Global Monitoring for Environment and Security Atmosphere Core Service (GACS) Implementation Group Final Report

Transcription

1 Global Monitoring for Environment and Security Atmosphere Core Service (GACS) Implementation Group Final Report April 2009

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3 Executive summary Context Atmosphere-related services already exist and are quite successful as regards dynamical/physical (meteorological) characteristics. It is however through the chemosphere (i.e. the atmosphere with emphasis on its chemical components) that humankind demonstrates a capacity to modify atmospheric properties and ultimately the climate. Here too atmospheric services already exist. International bodies like UN ECE-EMEP, WMO and the European Environment Agency coordinate, to some extent, the international monitoring and modelling of greenhouse gases, the ozone layer and air quality; these activities are further organised on a national scale. Following the implementation of the EU legislation on air pollution, air quality monitoring networks have been set up, emission inventories are reported, and modelling tools are playing a growing role. Still, the picture is far from complete: there are considerable needs and also potential for improving capacities and consistency. The GMES Atmosphere Services (GAS) 1 and its Core Service (GACS) aim to address this gap by integrating the monitoring & modelling of every atmospheric constituent at global & regional scales, and enabling further services at more local scales. MACC, a pilot project for GACS, is scheduled to begin middle of By then, some key elements of the core service should be ready to run in preoperational mode. Approaches originally developed for meteorology will be used in and by the GACS, e.g. integrating developments from the science community, numerical modelling and tools for operational implementation. The GACS will improve the description, understanding and forecasting of atmospheric species. At the same time the core service will expand our understanding by monitoring surface fluxes (emission/deposition) and performing scenarios to support and take into account policy decisions. Scope of GAS GAS and its service chain aims to serve a broadened community of users. Achieving this is the main challenge. The Service should meet the needs of users/actors at both European and national levels dealing with policies on air quality, renewable energies, climate change mitigation and adaptation as well as the protection of the ozone layer. Focus is on supporting international commitments for these policy areas, (e.g. Montreal protocol, Kyoto protocol, CLRTAP), in particular for established requirements set out in documents such as GCOS 2nd Adequacy Report or IGACO. The user communities for these services are wide ranging and includes environmental authorities and agencies, meteorological & health agencies, NGOs, research/science community, private sector, developing countries, other GMES services, and - last but not least - EU citizens. The GACS will address 4 themes: air quality, climate forcing, stratospheric ozone (plus UV radiation), and solar radiation. For each of these themes, atmospheric quantities needed are: 1. Air quality, over Europe: surface concentrations of pollutants: PM (particulate matter) in several size ranges, O3, NO2, NO, volatile organic carbons (VOCs), hydrocarbons, SO2, CO, HCHO, CHOCHO, C6H6; Emission fluxes of NO, NO2, CO, CHOCHO, PM; 1 A glossary of acronyms is provided in annex 2 April 2009 Report of the GAS Implementation Group 3

4 3-dimensional concentrations of O3, NO, NO2, CO, SO2, HCHO, C6H6, particulate matter; Emphasis on time resolution (hourly) and near real time (NRT) data availability. 2. Climate forcing, at global scale: 3-dimensional concentrations of CO2, CH4, O3, aerosols, active nitrogen components (NOx), vertical distribution of tropospheric essential climate variables, including water vapour, O3, halogenated hydrocarbons, VOCs; Surface and upper air physical and radiative parameters: temperature, pressure, wind speed and direction, water vapour, earth radiation budget and solar irradiance, cloud properties; 3. Ozone, UV and solar energy: O3 total columnar content and vertical distribution; stratospheric clouds, concentration of ozone destructive species (ClO, NOx...) Surface UV-B, UV index; global UV spectral irradiance, multichannel irradiance, erythemal irradiance Global horizontal (GHI) and direct normal (DNI) irradiances, with emphasis on time resolution. The outputs of the GACS should include both data products and elaborated products. The former include easy access to observational data, data delivered in Near Real Time (NRT) (especially for AQ), GCOS essential climate variables (CF), and gridded fields. Elaborated products are forecasts and analysis products, i.e. long-time trends as established by reanalysis, and low volume information and scenarios for policy makers, as well as the identification of sources and sinks. Added value is derived from combining space and in-situ observations and assimilating them in models. GACS will interface with other GMES Services with regard to climate change, the identification of sources and sinks as well as for emergency situations. Core & downstream services The implementation of GAS is based on a service chain concept. Core Services are defined as common European information capacities designed to meet common data and information requirements of a broad range of application areas. In the case of GACS, three criteria are accordingly identified: Focus on wide geographical coverage : global, regional (i.e. European) scale; Address the needs of downstream services & end users; Avoid duplications of efforts and operations. Downstream services (DS) build on GACS products, add value to them and produce more specific, tailored applications. Examples include local air quality forecasts, improved air-quality-related alerts and forecasts by health services, information to enable effective air pollution abatement measures, identification & monitoring of regional/local sources and sinks of greenhouse gases, potential analysis and energy yield mapping for solar energies. Downstream services are outside the scope of EC, in terms of both governance and funding In situ observational infrastructure In situ in the GMES context is used to refer to all non satellite data/products: ground based in-situ as well as remote sensing measurements from routine aircraft. For GACS, the major role of the in situ data is to deliver (i) an input to local, regional and European air quality models for assimilation and validation purposes; (ii) enable monitoring of long-term trends of air quality, greenhouse gases and ozone; and (iii) ensure the validation of satellite retrievals. There is a wide range of R&D, semi-operational and operational networks in existence which together create a good foundation for the GAS in-situ infrastructure. The main capacities for AQ are national April 2009 Report of the GAS Implementation Group 4

5 and regional AQ networks, the EMEP network, and near-real-time initiatives (e.g. EEA NRT AQ, IAGOS, AirCE). For UV, the European UV network is the main capacity. Tropospheric content and profiles relies mostly research funding, e.g. for aerosols EUSAAR, EARLINET, AERONET, for greenhouse gases CarboEurope, ICOS, NitroEurope and for aircraft observations MOZAIC being expanded to IAGOS. Data is also provided by national meteorological services and the GAW network (for O3 and greenhouse gases) as well as global networks collaborating with GAW: NDACC (atmospheric constituents in free atmosphere), SHADOZ (O3 sondes), TCCON (carbon) and BSRN (radiation). Identified shortcomings relate to spatial coverage and sustainability. It is recommended to: optimize the spatial distribution of air quality stations (aiming at the priority regions: Balkan and Mediterranean areas; Eastern Europe); build a European highresolution AQ emission database; to address under-sampling of GHG in remote (marine) areas; to relocate O 3 monitoring capacities in Europe (which is heavily over-sampled) to Asia, Africa and Latin America. AQ capacities are mainly operated at MS levels, these are a key to enable the GACS and the sustainability of these activities should be assured by MS. There is also a strong need to consolidate monitoring activities which are often supported by R&D funds (such as those carried out by ICOS, AERONET, EARLINET, IAGOS, etc.) and sustain these, eventually as European contributions to international observation networks. Data management is another critical issue for the in-situ observation infrastructures, and includes: (a) timeliness (the need to establish mechanisms for NRT provision of AQ, total O 3, UV and radiation data (the latter at 15 min intervals) observation data to GACS; and (b) in the case of greenhouse and reactive gases, aerosols and ozone, the need for a single portal as well as the harmonization of multiple-source datasets. This latter requirement includes intercalibration and creation of common standards for metadata & data (functionalities currently provided through the FP6 GEOmon project). The issue of access to meteorological data for downstream service providers has been addressed. A "GMES labelling" of the pertinent data should enable this access for identified users and for GMES purposes. European coordination mechanisms are urgently needed for: a) Institutional issues (co-management of the infrastructure to ensure availability and appropriate evolution, co-funding approaches, international cooperation issues), and b) Technical issues (observation infrastructure consolidation and evolution, data quality and standardization, and data management). Concerning the latter, international frameworks are key drivers for calibration/validation and data standards. To address the issues, the EEA as coordinator of the In situ component will have to play a leading role in the consolidation process. The current developments with regard to the implementation of the INSPIRE directive and the SEIS framework will similarly impact on the availability and accessibility of the data. The direct links between GMES and these initiatives will have to be clarified. Further guidance on the development of the in situ component is to be provided by ISOWG in consultation with the GACS IG and the GACS providers. As regards funding, Member State commitment is needed on the long-term availability of in-situ observation infrastructure required by GACS and related data access mechanisms (including sustainable data policies). Possible areas for EU support include (i) the filling of gaps in observation infrastructure e.g. helping relocations, development of networks in Eastern Europe or outside Europe; (ii) Pan-European observation infrastructures; (iii) European contribution to international networks (through European infrastructure); (iv) Technical (e.g. cal/val facilities, data management) & institutional coordination activities. April 2009 Report of the GAS Implementation Group 5

6 Space observational infrastructure Remote sensing techniques from space on their own do not provide satisfactory measurements of surface concentrations. On the other hand, they demonstrate improving capacities for measuring columnar content and estimating concentration profiles, with full global/regional coverage and the required time resolution. This depends, of course, on optimized "chemical" payloads being onboard space missions in adequate combinations. The highest priority is to guarantee the continuity of space observations with stable operation performances and quality. A number of European capacities relevant for GAS exist. These capacities include the "chemistry" payload onboard ENVISAT (SCIAMACHY, MIRAS, GOMOS), IASI, GOME-2 onboard MeToP and MSG/SEVIRI, MeToP/AVHRR, ENVISAT/MERIS (for fires, aerosols, clouds). Also worth mentioning is the European OMI instrument on NASA s AURA. These capacities do not comply with the required (hourly) time resolution for air quality measurements. Furthermore, they will be substantially weakened at the end of ENVISAT's operation. With this in mind, a future scheme including the low orbit Sentinel 5 (in the Post-EPS time frame) and a geostationary Sentinel 4 payload (in the post-msg time frame) has been prepared. Assuming that thermal infrared missions remain part of the core payload of EUMETSAT space missions, it is recommended that: ENVISAT lifetime be maximized in order to narrow the time gap before the Sentinels 4 & 5 become operational; a UVNS spectrometer (Sentinel-5) be accommodated on a Post-EPS platform, alongside IRS and VII; a UVN spectrometer (Sentinel-4) be embarked on MTG-S (for AQ dense sampling); a UVNS spectrometer (precursor of Sentinel-5) be made available around 2014, in a polar orbit complementary to EPS/MetOp (global AQ); ESA & EUMETSAT align their mission requirements & implementation agendas The geostationary "chemical payload" (Sentinel-4) is expected to bring a wholly new capacity. This capacity will move beyond improved time resolution and forecasting, to creating a new vision and understanding of relevant phenomena. It is also recommended to address pertinent ground segment issues such as the need for a direct interface between GAS data acquisition and mission operators; and to enable the proficient use of existing dissemination infrastructures (e.g. EUMETCAST, GEONETCAST) as well as the EUMETSAT SAFs for GAS purposes. International cooperation is needed in order both to provide redundancy and also to complement European observation capacities. A relevant example is the absence of a Limb MMW/IR profiling mission (which is important for the UTLS) in the planned European missions outlined above. Clear and early planning is needed to build global cooperation agreements for operational systems in the frameworks of WMO, CEOS and GEO. On this basis, EU should engage in dialogue with the USA (interest in AURA, OCO, limb sounding mission, future possibilities) as well as with other countries: Japan (JAXA, NIES), China, Canada, and South Korea. Concerning R&D, several missions were identified as having high relevance for the GACS. These include the ESA Earth Explorer programme, for which GACS requirements and priorities should be considered during its selection stage. For selected missions, the usefulness and contribution for GACS should be assessed for example to address requirements not met by existing and planned capacities. Improving the measurement of atmospheric CO2 from space is a major R&D issue which requires ESA R&D efforts and funding to be maintained. Moreover, in-orbit capabilities of USA's OCO & Japanese GOSAT should be assessed in order to define a long-term observation approach at European & international levels. April 2009 Report of the GAS Implementation Group 6

7 Issues for data exploitation that warrant further R&D include: addressing calibration / validation issues and the link with GAS operational requirements, enhancing efforts for direct / retrieval modelling, and enhancing efforts and related funding (from EC, ESA and EUMETSAT) for deriving trace gas products from IASI and GOME-2 in order to transfer these products efficiently into the operational GAS domain. 2 Functional architecture The functional architecture of GACS is suggested to consist of five elements. Observation acquisition and pre-processing aims to interface with data/product providers (space agencies, international & research missions, NRT and delayed in situ data providers, emission data and meteorological data) and perform quality control of inputs, validation and blending for modelling use. "Global monitoring, assimilation and forecasting" turns the quality-controlled observations into assimilated global fields and produces global forecasts as well as emission fluxes. The Ensemble of European-scale monitoring, assimilation and forecasting systems element will combine the outputs of several models ("ensemble" approach) at European scale to produce fields and forecasts. Data and Products Services is the user interface, assuring the dissemination of all CS output products to the users and assuring the quality of these products. End users will provide feedback upon which the GACS portfolio is established and updated. The fifth element Core R&D will allow the GACS to analyse problems in all GAS parts and processes, make required quick fixes and drive R&D on specific short term issues. The core service mainly interacts with: Data providers from both space and in situ infrastructure; Upstream R & D at EC and national levels for long term issues; Other GMES services (marine, land, probably emergency in the future), for example for conducting harmonized reanalyses; Users (mechanisms such as service level agreements will ensure efficient interactions with both end users and downstream services. Users will be encouraged to join federations in order to enter such agreements. Governance The GAS is expected to depend on an overall GMES governance organisation, encompassing every GMES service. At service level, the governance for GACS will have to oversee GACS provision and evolution and enable the prioritisation & arbitration, linking with the GMES governance. A board is needed to involve: (a) Users (European, national, private) represented at the appropriate level; (b) GAS providers, e.g. institutions contributing through their own capacities & resources; and (c) Observation data providers. 2 Based on the work of a dedicated working group on space infrastructures, recommendations were issued by end of March 2008 and communicated to the space agencies. A workshop bringing together members of the space working group, the GACS implementation group (IG), the GMES Bureau as well as ESA and EUMETSAT was held on April 25 th. As outcome, it resulted that IG recommendations were fully taken into account by ESA & EUMETSAT and the preliminary assessment of the Sentinel MRD by the IG was positive. For the future it is envisaged that the IG be represented in the ESA/EUMETSAT mission advisory process. April 2009 Report of the GAS Implementation Group 7

8 An Advisory Body (functions similar to GAS IG) would prepare decisions of a scientific & technical nature. A GACS management body would carry out the Board's directives, manage the five core elements listed above, provide the institutional/technical interface with external entities including the EC and MS, and provide the overall management of the service including interfacing to other services. An appropriate legal structure for the GACS service provision is still to be defined in discussions with the EC. Such a structure, should capitalize on the strengths of the consortium created for the MACC pilot project as well as allowing evolution of the partnership without endangering the continuity of the service. Implementation process Bearing in mind the year 2014 as a starting point for the fully operational GACS a number of drivers and processes should be taken into account for an articulation of an implementation strategy. There must be a flexibility to incorporate advanced methodologies (e.g. full coupling of chemistry & dynamical/physical models & new capacities - e.g. ESA's Sentinel-4 data by 2017+). The ongoing pre-operational activities (e.g. projects GEMS, PROMOTE and MACC in the future) should serve as platforms to initiate GACS implementation. In addition to the recommendations spelled out in the sections on observation infrastructures, user engagement must be assured with the help of service level agreements in MACC and any follow-up projects. The level of resources devoted to R&D activities essential for a GACS evolution (namely in the areas of observation technology & related physics; modelling & observation assimilation techniques; and service applications including the downstream sector) should be maintained. It appears useful that the Implementation (or similar) Group should carry on in order to advise on the consolidation and validation process of the GACS and contribute to the seamless transition of preoperational GAS activities into a fully-fledged GACS. To this end, an action plan was prepared over the fall period, with following actions: : assess governance principles defined in EC GMES communication, elaborate further on interfaces between GAS core and downstream services, start reviewing interactions with user communities in pilot phase as well as interaction with EEA on coordination of in situ observation infrastructure for GAS : give advice on funding issues in detail (including cost estimate of the GACS provision, and EU support to in situ observation infrastructure) , monitor regularly the implementation of GACS though MACC (avoiding redundancy with the FP monitoring) in order to come up with guidelines for the setting-up of the GAS provision scheme and the related GAS coordination structure by the end Conclusions A number of issues still need to be solved in upcoming years: selecting the most efficient legal entity for the GACS, obtaining cost estimates for the operational phase and defining the ways to meet them. Also, setting up the coordination of in situ data providers undoubtedly appears as a complicated task. On the other hand, a solid foundation of considerable assets already exists, enabling a rapid progress toward an operational status for the GACS. The pilot phase will allow to better focus the services and prepare their upgrades, to stimulate the implementation of the service chain, and to develop the essential interaction with users. April 2009 Report of the GAS Implementation Group 8

9 Contents 1. Introduction The purpose of GMES Atmospheric Services (GAS) Building GAS More benefits to more users The scope of GAS Core Services (GACS) Political environment User communities Concept of Core Services (CS) & Downstream services (DS) Perimeter of GACS and envisaged products/information to be delivered CS themes Added value of GACS Prioritization of product types Limits / borderline of CS Service output parameters Cross-cutting issues to other services The required in situ observational infrastructure In situ observation needs for the GMES Atmosphere Core Service In situ existing observation infrastructure for GACS Shortcomings of the existing In situ observation capacities Geographical coverage and adequacy of the monitoring activities Sustainability of the observation capacities Availability of data Coordination mechanisms Funding and data policy issues International cooperation issues Research and Development Summary of conclusions and recommendations The required space observational infrastructure Space observation needs for the GMES Atmosphere Core Service Space infrastructure for the GMES Atmosphere Core Service Existing European observation capacities Future European observation capacities Ground segments and interfaces with GACS International cooperation issues Research and development European research and demonstration missions Research and development activities on data exploitation GACS functionality and architecture Core service functional architecture and corresponding existing assets Observation acquisition and pre-processing Global monitoring, assimilation and forecasting Ensemble of European-scale monitoring, assimilation and forecasting systems Data and products services and quality assurance Core R&D Existing assets External dependencies Satellite data In situ data Meteorological data Emission data Service delivery and interaction with users and downstream services Research and development outside of GACS Link to international bodies and coordinating activities Implementation strategy for GACS Foundations of the GACS...54 April 2009 Report of the GAS Implementation Group 9

10 6.2 Proposed strategy Service development: Observation infrastructure Operational service and perspectives Users R&D Funding Data Policy Guidelines Meteorological data Governance and management structures Principles Proposed governance structure Critical needs and service evolution Critical needs Evolution of GACS Future actions: tentative timetable...60 ANNEX 1: Working practices of the Implementation Group A 1.1. Principles of IG work and sources of guidance used...62 A Working approaches A Guidance A 1.2. The GAS Implementation Group...63 A Composition A Mandate A Workplan 2007/ A 1.3. Mandates and work plans of working groups (WG)...66 A WG 1: Scope of the Atmosphere Core Service A WG 2: Functionalities and Architecture of the GMES Atmosphere Core Service A WG 3: In-situ infrastructure and data A WG 4: Space infrastructure and data ANNEX 2: References and glossary of abbreviations ANNEX 3: Detailed outputs (scope) of the GAS A 3.1. Specification of CS products for AQ and CF in relation to the intended use...74 A 3.2. Specification of CS products for O 3 and UV in relation to the intended use...77 A 3.3. CS products for solar radiation...81 ANNEX 4: In situ priority capacities A 4.1. Air quality...83 A 4.2. Ozone and UV...86 A 4.3. Climate...89 ANNEX 5: Current capacities of space infrastructures & outlook until A 5.1. Stratospheric reactive gases global (columns)...92 A 5.2. Stratospheric parameters global (profiles)...92 A 5.3. Tropospheric aerosol...94 A 5.4. Greenhouse Gases (Global)...94 A 5.5. Tropospheric reactive gases (global)...95 A 5.6. Tropospheric reactive gases (Europe/Africa - regional)...96 ANNEX 6: Existing assets for GACS A 6.1. Observation acquisition and pre-processing...97 A 6.2. Global Monitoring, Assimilation and Forecasting...98 A 6.3. Ensemble of European-scale monitoring, assimilation & forecasting systems...99 A 6.4. Data Services...99 A 6.5. Further organisations of possible relevance April 2009 Report of the GAS Implementation Group 10

11 1. Introduction 1.1 The purpose of GMES Atmospheric Services (GAS) Anthropogenic climate change is recognized as a major issue as the third millennium begins. The atmosphere, which acts as a reservoir for greenhouse gases and aerosols, as well as its interfacial fluxes, is the critical element of this issue. For many other environmental issues, the atmosphere plays essential and diverse roles. Atmospheric mechanisms, which provide protection from UV rays or cause dispersion and conversion of pollutants deeply affect human health and the environment. The life of EU citizens is still on average shortened by 8 months due to the effects of air pollution and almost half the ecosystems within the European Union remain exposed to excessive eutrophication. European environment policies on air thus face significant challenges. As measures to address the impacts become increasingly complex and costly and sometimes requiring difficult trade-offs, the best possible information on the status of the atmosphere is needed to ensure an effective policy cycle. Atmospheric services already exist. The network of national weather services coordinated by WMO is achieving considerable and steadily growing success in monitoring and forecasting the dynamical and physical (in short: meteorological) properties of the atmosphere. It is however through the chemosphere (i.e. the atmosphere with emphasis on its chemical components) that humankind demonstrates capacity, for better or (more often) for worse, to modify atmospheric properties and ultimately the climate. Here too atmospheric services already exist. International bodies like UN ECE-EMEP, WMO and the European Environment Agency coordinate, to some extent, the international monitoring and modelling of greenhouse gases, the ozone layer and air quality; these activities are further organised on a national scale. Following the implementation of the EU legislation on air pollution, air quality monitoring networks have been set up; emission inventories are developed and reported; modelling tools are playing a growing role. Still, the picture is far from complete: there are considerable needs and also potential for improving capacities and consistency. Within GMES, GAS aims to integrate the monitoring and modelling of the physical and chemical state of the atmosphere on global and European scales. 1.2 Building GAS The success of weather forecasting is due to the fact that the time behaviour of the meteorological atmosphere obeys a set of coupled time-dependent differential equations. In other words, the dynamics of the atmosphere are well represented by a model that can be implemented in numerical simulations, with such a growing efficiency that the term model has now come to refer to the numerical algorithm itself. Currently, atmospheric chemistry and meteorology are mostly dealt with separately: dynamical analyses and forecasts (assumed not to depend upon chemical processes) provide the input dynamics to chemical modelling. However, the real atmosphere is a fully interacting medium, which will be best represented and forecast through integration of chemical and physical phenomena. Through advances in science and computing power, this integrated dynamical approach is rapidly becoming feasible. The approach is dependant on the availability of satellite observations and ground based monitoring data on continental and global scale. The principal tools of GAS are expected to be dynamic modelling, state-of-the-art atmospheric chemistry modules and data assimilation. Inverse modelling will also be used extensively to infer emissions and depositions from the surface beneath the atmosphere (i.e. the atmosphere lower boundary condition) using measured concentrations. April 2009 Report of the GAS Implementation Group 11

12 The meteorological community has succeeded in gathering a strong research community, and setting up a number of centres endowed with considerable competence in numerical modelling. GMES, in its development of GAS, aims to combine these capacities with those developed in the field of emissions and air quality monitoring, modelling and projections, human health and ecosystems effects assessments and abatement response. Similarly, the experience gained by meteorological services and other capacities, for example for organizing operational observation from space, and setting up information/communication systems, should be fully exploited to achieve the objective to create an operational, sustainable atmospheric service at EU level. In recent years, a series of focused research and development initiatives to improve modelling of the ozone layer, air quality and climate forcing have been undertaken. MACC, a pilot project for the core of GAS, will begin middle By that time, some key elements of the core service should be ready to run in preoperational mode. This provides a perspective to evolve smoothly and quickly toward the operational phase. 1.3 More benefits to more users What are the benefits of such an integrated Atmosphere Service? Not only the overall picture of what happens in the atmosphere will be more detailed and more accurate, but also it will be clearer why things happen. The largest advantages will occur in fields where both meteorological and environmental worlds meet. There will be improved understanding of climate and climate change. Complicated problems, such as the interaction between climate change and ozone layer depletion or air quality, will become easier to address. The GAS will provide more detailed information on trends in atmospheric concentrations, variations in sources and sinks of gases and aerosols, as well as underlying chemical processes. In addition, GAS will support improvement of weather forecasts. Whereas meteorological surface fluxes of momentum and energy are dependent, predictable parts of the whole system, this is not the case for chemical components, as these fluxes also strongly depend on anthropogenic activity and policy choices. Through scenario studies, univocal forecasts will be expanded, when accounting for the chemosphere, into a series of forecast scenarios depending upon man-made decisions. GAS is expected to serve a broad community of users. The core service, developed and maintained at the Community level and serving principal users in support of European environmental policies, is complemented by downstream services. The latter exploit the outputs of the core, facilitate further work at more local level, or serve more specific users and uses such as the efforts of the health community and local administration to reduce public exposure to the air pollution. Such a service chain concept provides a solution for integrating users and their needs in a flexible and efficient way. Achieving a successful implementation of this scheme will be a major challenge for GAS. April 2009 Report of the GAS Implementation Group 12

13 2. The scope of GAS Core Services (GACS) 2.1 Political environment The GMES atmosphere service orientation paper and December 2006 user workshop conclusion document provide a good overview of relevant European level directives and regulations, as well as commitments of the European Union at the international level. The most relevant legal documents or policy initiatives are: 6 th Environmental Action Programme (EC, DG ENV) setting out European environmental policy objectives for ; mid-term review published recently ec.europa.eu:8082/environment/newprg/index.htm Shared Environmental Information system (SEIS) COM2008 (46) final: INSPIRE Directive: Air quality legislation Clean Air for Europe programme (CAFE), in particular the Thematic Strategy on air Pollution ec.europa.eu/environment/air/index.htm The new Directive on ambient air quality and cleaner air for Europe including provisions for harmonised monitoring requirements for MS as well as informing the public and regulating fine particles PM 2.5 levels for the first time Convention on long-range transboundary air pollution (CLRTAP) Climate changes policies UNFCC and Kyoto Protocol: Unfcc.int/kyoto_protocol/2830.php European Climate Change Programme (ECCP): ec.europa.eu:8082/environment/climat/eccpii.htm Green Paper on Adaptation to CC, White Paper to follow in fall 2008: ec.europa.eu:8082/environment/climat/adaptation/index.htm EC communication "Limiting Global Climate Change to 2 Celsius: The way ahead for 2020 and beyond." and related documents on EU climate policy ec.europa.eu:8082/environment/climat/future_action.htm Stratospheric Ozone Vienna Convention and Montreal Protocol: ozone.unep.org EU policy on ozone: ec.europa.eu:8082/environment/ozone/community_action.htm Solar Radiation Several EU policy initiatives in the filed of CCE (Climate Change Energy) including the promotion of renewable energies, increased energy efficiency and increased use of environmental technologies, e.g. Commission communication by 2020 Europe s Climate Change Opportunity : ec.europa.eu/energy/climate_actions/index_en.htm; including a proposal for a directive on the promotion of the use of energy from renewable sources ( ): ec.europa.eu/energy/climate_actions/doc/2008_res_directive_en.pdf and existing Directive 2001/77/EC on the promotion of the electricity produced from renewable energy source in the internal electricity market; Green paper: A European Strategy for Sustainable, Competitive and Secure Energy; Renewable energy road map In addition, background documents have been produced in the above international context, which outline the challenges ahead and the current shortcomings to meet them with regard to atmospheric composition, and which GMES should help to address: April 2009 Report of the GAS Implementation Group 13

14 The GCOS 2 nd adequacy report, GCOS implementation plan and satellite supplement address inter alia the observational needs regarding a better understanding of the climate system The IPCC 4 th Assessment report summarizes the current understanding regarding climate change: The IGACO-Report establishes inter alia the requirements for observations of atmospheric composition at international level: User communities Users of GMES Atmosphere Services include the following: European institutions and agencies (European Commission: DG ENV, JRC, EEA,..) International bodies in support of conventions (e.g. CLRTAP/EMEP; IPCC; WMO; UNEP,..) National and regional authorities and environmental agencies, networks (EIONET, IMPEL ) National meteorological services Specific communities: modelling, research/science, EU research projects EU citizens Health services NGOs Other GMES services Private sector including industrial federations Less developed countries. These users expect different types of products; generally it may be distinguished between users that need predominantly (a) high-volume data/data products based on monitoring or resulting from modelling, in contrast to those that rather need (b) low-volume, but highly elaborated products. Typical examples for (a) are e.g. the research/science community and meteorological services, while (b) are e.g. policy makers. 2.3 Concept of Core Services (CS) & Downstream services (DS) The GMES Atmosphere Services will be based on a Core Service (CS or GACS), which provides data and products either directly to (end)-users or to the providers (="intermediate users") of Downstream Services (DS). The DS are outside the scope of EC, in terms of both governance and funding. In practical terms however, all services using or benefiting from the GACS implementation should be considered GMES Atmosphere services. Whether they should be included in the GACS itself depends on the "European added value" of the services: A. CS will generally seek to provide information at scales such as pan-european, or even global. B. Information products should be provided through the CS if they are better generated once than many times in parallel by more local providers, according to the economies of scale principle. This does not however exclude "ensemble" products where synergy of products from multiple providers is used to improve the robustness or accuracy of the product. Hence, the mission of the GACS will be to produce in real-time operational, generic, multi-purpose data to monitor the composition of the atmosphere at global and European scale. The data will be composed of analyses of the state of the atmosphere for the current day, forecasts to a few days ahead, and homogeneous reanalyses of past periods. The Core Service will rely on GMES funding and provide direct support to European policies and information on global issues. April 2009 Report of the GAS Implementation Group 14

15 The GACS will also deliver these data services that are indispensable inputs for the DS. The DS, in turn, will seek to create targeted services tailored to meet specific user requirements. These specific products may extend to sectors far beyond air policy, such as health or transport. Expectations are that most DS will primarily support needs at national, regional and local level, generally through downscaling and assimilation of more specific/local information. Dependency on a common GACS should facilitate development, increase consistency, comparability and subsequent improvement of such DS. Key characteristics of DS are hence their dependency on the GACS as well as the involvement of a decentralized network of service providers usually in close contact with specific users. This is of particular importance in the case of public information, where a local face for the information is required. A typical example for the division of labour between CS and DS (in the field of Air Quality - AQ -) is the case of forecasting AQ levels to citizens: A number of regional/local DS provide citizens with relevant short-term forecasts on the quality of the air in their immediate environment, taking into account local specifics including microenvironment, culture and language. But these DS will depend on a GACS that will provide - as a result of larger-scale (regional/global) modelling - the necessary boundary conditions for the local models, improving the accuracy and reliability of the DS 3. In the following, an indicative, non-exhaustive list of DS is presented: Air quality Local air quality forecasts (urban scale). Improved air-quality-related alerts and forecasts by health services supporting vulnerable communities (chronic obstructive pulmonary disease, respiratory diseases, asthma (including pollen-induced allergies); Supporting integrated air quality indices. Enhanced assessment of air quality within a specific region, supporting development of effective air pollution abatement measures through proper apportionment of sources and assessment of impacts (human exposure) etc. Improved air-quality-related alerts and forecasts for extreme events involving the combined effects of heat stress, high UV-B exposure and poor air quality; Analysis of national, regional and local air pollution abatement policies and measures through inverse modelling, validation/improvement of emission inventories and reconciling bottom-up and top-down emission inventories; Support to implementation of indicators related to following different aspects of policy effectiveness, as for example public exposure assessment, transboundary contributions (at a particular site/regions, rather than at large scale), footprint of cities, contribution from a transport mode etc. Climate forcing Identification, assessment and monitoring of regional/local sources and sinks of Greenhouse Gases and pollutants and related tracers in support of emission and sink verification and mitigation policy. Stratospheric ozone and solar radiation Solar-radiation potential analysis, policy scenario analysis, energy yield mapping, support to electricity transmission network management together with site audits and plant management for solar power plants. 3 This concrete example already exists: e.g. (Downstream) services provided by AIRPARIF on AQ in Ile de France (Paris region) receive boundary conditions from FP6-project GEMS and their regional ENSEMBLE modelling component. April 2009 Report of the GAS Implementation Group 15

16 2.4 Perimeter of GACS and envisaged products/information to be delivered The objective for the GACS is to produce outputs for the relevant users with their differing requirements, as identified above. These outputs should provide added value with regard to existing information and should not duplicate operational and sustainable services already in existence CS themes The four primary themes of the GACS are: 1. Climate forcing (CF); 2. Air quality (AQ); 3. Stratospheric ozone (and UV); 4. Solar radiation. These themes are to be complemented with horizontal services across the themes such as NRT satellite data provision and so-called toolboxes. In addition, there are specific recommendations on the initial CS, such as the need for re-analysis, brought forward in following subsections. AQ and CF represent the major components of the GACS and should be considered first priority, due to their relevance to many different kinds and types of users, their estimated uptake by downstream users (especially AQ) and the high relevance to policy and research (especially CF). A second priority for the service should be Stratospheric ozone; while much already exists today to satisfy the high relevance of these data to policy, long-term funding of observations is not secured. Finally, solar radiation has relevance to policy, but a stronger focus on downstream users in the private industry. The support of renewable energies in the field of wind is not considered to be part of the scope, as this would encroach upon already existing and future services provided by the meteorological bodies. In addition, unlike solar energy, wind energy is generally not affected by atmospheric composition parameters Added value of GACS In order to properly justify a GACS there is a need to produce added value on existing services and products. The CS should fill the user-identified gaps in the accessible information on atmospheric chemistry and provide the needed monitoring data to support policy needs. To fulfil its role regarding the monitoring of atmospheric chemistry/composition, observational data (space & in situ) from the themes AQ, CF and stratospheric ozone are essential. For stratospheric O 3, current efforts of collecting relevant observations are quite substantial already ( IGACO report 4 ), but there is a risk of degradation of the existing infrastructure due to lack of sustainable funding. For AQ, current efforts of collecting relevant information are similarly plentiful already. However, there are some identified gaps in spatial coverage, and in particular in ensuring effective access in NRT to support several CS. CS should maximize the added value through optimization of combined use and common access of remote sensing and in-situ observation monitoring, overcoming current shortcomings that limit applicability of either. The combination through data assimilation, at EU scale, is expected to bring core added value to CS, while ensuring effective access to in-situ and satellite observation, including near real time (NRT) data. This in turn will facilitate acceptance and further improvement of CS and foster development of optimized downstream services. Solar energy technologies are an important example of this vision. 4 April 2009 Report of the GAS Implementation Group 16

17 The provision of GCOS essential climate variables (ECVs) should be regarded as a priority for the atmosphere service and thus a main driver for the climate forcing service theme to be provided. The current situation in Europe is as follows: Surface ECVs: Many centres already do this and meet user requirements, e.g. gridded monthly, seasonal and annual averages. However, research users, in particular, would like to have better and increased access. Upper-air ECVs: Temperature, wind and radiation budget are already available from other providers. Access and user specification may need improvement Composition ECVs: There is a clear user requirement to do more than currently exists, especially with regard to gridded information. For environmental policies, the establishment of trends based on long-term data is extremely relevant: For this purpose, high precision data with regard to space and time over long periods of time (several decades) is needed. Whilst a number of databases with observational data already exist, their specific objectives and/or limited access show significant potential for CS to add value. CS should ensure proper archiving and effective access to the core data/information as identified by users. Besides its monitoring capabilities, the GACS CS should also have forecasting and predictive as well as analysis capabilities: The added value and the value for money should be in providing new common services and products with at least EU-wide coverage that support a range of policies across several sectors including climate change mitigation and adaptation, air pollution abatement, health and biodiversity, aviation plus other transport modes, weather forecasting etc. In some cases, CS added value may be ensured by cost-effective, optimized analysis methodologies through ensemble modelling benefiting from access to single harmonized data input. CS added value may come also from the economies of scale this should be demonstrated in advance through a solid user base Prioritization of product types As regards the priorities within the four themes, the following recommendations are made: Addressing gaps in the information on atmospheric chemistry/composition should be regarded as an initial priority. The joint, proficient use of satellite and in situ data should be put to good use to address this priority. In addition, the CS should also enable forecasting, allow predictions and analysis. Policy relevance, user relevance, added value on existing services and/or economies of scale justify the inclusion of such services within CS. For the latter services, the main areas of interest are: 'Low volume' information: indicators, aggregate information, added value documents such as assessments or scientific reports; Services with a strong user uptake and providing economies of scale such as services in the area of health and transportation (aviation, ground), supporting DS such as alert services for relevant events in air pollution and UV exposure; Provision of AQ scenarios (at European scale) to evaluate impact of policies or beneficial strategies to reduce pollution, especially because the step from calculating assimilated global and European 3D fields to prognostic fields is not very large; Confirmation of anthropogenic emissions (based on inverse modelling and satellite data) in MS as well as at global level (rapidly evolving economies) as well as the identification of sinks; April 2009 Report of the GAS Implementation Group 17

18 Clarification of the contribution of emission sources (e.g. agriculture emissions of methane, NOx and N2O and forests emissions of VOCs, GHG, fires/sand-dust storms); validation / improvement of emission inventories. Importance of transboundary transport, including the hemispheric scale Some other remarks: The theme CF should have an initial focus on gridded data for atmospheric composition, in addition to relevant observational data such as that derived through the in situ measurement infrastructure. The GACS evolution process may include a move from providing GCOS atmospheric ECVs on composition towards a provision of all GCOS ECVs, with contributions from the marine and land CS. Reanalysis: A focus of going back further in time (up to 1930, 40 with CC data), achieving better resolution & coupling upper air with ocean/land state parameters, using a multi-model approach with improved (and 4D) modelling capacities now available in order to provide better information as compared to existing efforts such as ERA-40 is clearly useful to climate modelling, but also for air quality and related fields. There are obvious advantages to including reanalysis work within a GACS and providing such an exercise at regular intervals, rather than depending on research funding outside of the operational service Limits / borderline of CS While the line can be drawn between the GACS and its DS with relative ease, it is more difficult to define the limits of GACS with regard to services already existing today. Hence, there are some ambiguities on the borderline of the CS, e.g.: In case of an existing service, it should not become part of the CS, as we are aiming to build added value; however, integration in a CS may be considered in some cases in the process of service development; Some specialised, targeted products for a direct user should also be within the scope of GACS, especially if providing EU added value (e.g. policy relevance) With regard to access to observational data: here it is key to avoid duplication (e.g. with meteorological bodies): if data is already available somewhere, then this should not be done by the GACS; however, if such data is relevant for some GACS products or other GMES-CS, then these data should be included in the scope. For solar energies: as support is considered to be within scope of GACS, then the needed data/observations should be part of the GACS. Identified DS depending on observational data including meteorological data and raw satellite data should be able to obtain such data; it would therefore be appropriate to issue a "GMES label" for such data to show that it is included within the GACS umbrella, enabling open access to identified DS providers for GMES-related use. A few examples, which also take into account the identified priorities (section 2.4.3) follow below Atmospheric composition In-situ and satellite observations already play a key role in the context of providing data needed for EU and MS obligations under EU legislation and in UNFCCC, CLTRAP and the Montreal Protocol. CS are not meant to duplicate or take over the established exchange mechanisms, but to provide added 5 Large-scale re-analysis for climate purposes may become part of the GACS Core Service. Alternatively, funding for such efforts needs to come from R&D framework programmes. (e.g. cooperation with FP6 projects ENSEMBLES, and CECILIA, In AQ, reanalysis may be even more important due to larger number of pollutants/measurement methods/siting criteria which provide further challenges in ensuring a coherent picture and establish reliable long-term trends. April 2009 Report of the GAS Implementation Group 18

19 value following the principles described above. It is however likely that some existing data-flows will subsequently be modified to take advantage of GACS 6. Satellite data While GACS should not be considered as an alternate satellite data provider, there is scope within GACS for provision of validated and quality controlled selected set of (multi-sensor) satellite data of known measurement uncertainty (such as atmospheric column data on trace gases, aerosol distributions, solar radiation etc.). The greatest value is obtained from these data if user needs are considered, i.e. that for high-capacity AQ users, data is provided in conjunction with maximal information on their vertical distribution. Data are needed at high temporal and spatial resolution to monitor processes with a relatively short atmospheric lifetime. The direct use of satellite data for other users without interpretation (e.g. DS) is limited. Concentration data In analogy to the above, GACS should not be considered as alternate in-situ observation data provider to the numerous networks already in place. However, the provision of ground-level concentration data for relevant pollutants such as PM2.5, PM10, O 3, NO 2 in µg/m3 is considered to be within GACS. These data should already carry the added value of GACS quality control, data assimilation with emission dispersion modelling and remote sensing incl. satellite observations to ensure adequate quality, comparability, spatial and temporal resolution. To ensure the 'buy-in' by the users as well as facilitate further improvement of the service, individual components of the system (i.e. in-situ monitoring data, dispersion modelling outputs etc.) should also be available separately as GACS. NRT in-situ and satellite data The GAS user workshop (December 2006) included in the scope of GAS ( Table 1) the provision of NRT satellite-based products, which are not currently being provided operationally by satellite data providers. Table 1: required satellite products as identified in the Dec 2006 user workshop NRT satellite products Data type Extension Tropospheric O3 column NRT satellite Europe Ozone profile NRT satellite Europe SO2 NRT satellite Europe Tropospheric NO2 NRT satellite Europe CHOH (plus CHOCHO?) NRT satellite Europe PM (types) NRT satellite Europe CH4 NRT satellite Europe CO2 (CO?) NRT satellite Europe Aerosol optical depth (column) NRT satellite Europe Dust NRT satellite Europe Solar radiation NRT satellite (Meteosat) Europe O3 total column NRT satellite Global Tropospheric NO2 NRT satellite Global GACS should support the better availability and usability of Level 2 and 3 satellite data, including radiance data. It is also evident that access to NRT in-situ data needs to be provided at least to 6 In such case, they should be recognized as DS, and appropriate account should be taken in ensuring that their needs are taken into account. April 2009 Report of the GAS Implementation Group 19

20 modellers developing the assessment/forecasting of AQ, and most probably to its users as well (see 2 above). GMES implementation should promote open data access policy; however the provision of basic observational data to end users should not be part of GACS. Access by high capacity users to the data collected in order to enable related CS should nonetheless be made possible within GACS Products other than atmospheric composition Meteorological data Meteorological data such as clouds (an important CC variable) or wind and precipitation (essential input in AQ assessments) are already provided in a sustainable and operational manner by the national meteorological services. Provision of such data should be beyond the scope of CS. The implementation of GACS should only ensure that GACS has an effective access to this data. There may however be GACS products which build strongly on such input, but already present added value to GMES users; examples include filtering and resampling these data to feed directly in GACS models. Such products may be offered separately as part of GACS. Sources and sinks An important category to be considered is the information on sources and sinks, which is a) essential in determination of gridded information on atmospheric compositions, and b) one of the key policy indicators. GACS should not make an effort to disseminate the related information collected from different sources, or provide an additional layer in reporting EU emission data. However, the subsequent gridded maximum spatial/temporal resolution inventory, together with some more aggregated information, should be considered part of GACS. There may be a number of related services envisioned such as validation/improvement of sources - emission inventories as well as sinks (refinement of atmospheric chemistry models, deposition etc.) through inverse modelling. They should be considered in the development of GACS as supporting tools in providing information of adequate and known quality. They should however at this moment not be systematically considered as specific CS, since some users may develop them as DS. It is expected that source/sink-related GACS and DS will, through feedback, influence the data provided (similar, but to a lesser extent, can be claimed for the observational data). Flexibility in the implementation of GACS should enable the possibility that in future some of the EU international reporting obligations may be taken over by GACS. Toolboxes Following in particularly the "economies of scale" rationale, there is scope for the provision of toolboxes based on additional modelling capabilities allowing to (interactively) further examine relevant phenomena, future scenarios / integrated assessment such as RAINS/GAINS, cost benefit analysis, to support adaptation strategies at various levels etc. Some of these toolboxes will need to be established in any case as part of the "generic services" of GACS supporting the sensitivity analysis, QA/QC, validation and further development of CS products. While all these services could be also considered as important DS, the following should be already now considered as CS: interactive toolbox enabling manipulation of inputs to data assimilation/models to further examine relevant phenomena; ability to describe future scenarios to obtain information on projected atmospheric composition, sources and sinks. Forecasting and identification of pollution episodes Building upon the assessment and forecasting CS specific information may be extracted linked to specific atmospheric events (e.g. long-range transport of air pollution, sand-dust storms, pollen, volcanoes, forest fires). Such CS should be explicitly targeting 'alert' DS linked to the further April 2009 Report of the GAS Implementation Group 20

21 processing and dissemination such as health warnings and exposure recommendations, triggering short-term actions plans such as urban transport restriction measures etc Service output parameters A description of desired service outputs for the different themes is attempted in the following. For all services provided, uncertainty assessments are crucial, in particular for assimilation modelling. The required temporal and spatial resolutions for CS parameters as listed in annex 3 should not be seen as absolute, as A. Temporal and spatial resolution often change whenever new measurement platforms or models are used; B. Data can easily be transformed into any resolution during the download process. Data processing and assimilation may provide information which is superior to its individual components such as in-situ or space monitoring data both in resolution as well as in quality. The resolutions indicated are based on currently identified user needs and are intended as minimum values Air quality (AQ) A GMES CS for AQ can provide added value regarding at least EU-wide surface monitoring, harmonization of AQ assessment, better integration of monitoring and modelling results, integration with satellite data and providing NRT concentration fields. Further, the envisaged CS products for AQ are based on atmospheric composition data that may be categorised as follows: 1. Type of Pollutant: a. Ozone b. Particulate matter/aerosol/soot (this includes industrial emissions and anthropogenic dust, sea spray and geogenic dust) c. NO2 d. SO2 e. CO f. HCHO g. CHOCHO (Glyoxal; tracer of VOC emissions) h. C6H6 2. Parameters: a. Concentrations of pollutants (e.g. PM1, PM2.5, PM10): first and foremost 2D surface grids are required. For some applications, e.g. long-range transport of pollutants, aerosols for cloud formation modelling, 3D tropospheric grids are also needed; b. Integrated quantities (optical depths, columnar contents) and profiles; c. Other, such as sources and sinks (emission, deposition estimates, atmospheric removal rates). 3. Periods 7 (including temporal resolution and provision frequency): a. Historic data (data anywhere in the past, e.g. the last 10 years) as 3h time resolution and 1d/month/season/annual statistics; last year s data to be provided annually; b. (Near) Real Time data ( now 8 ) as 1h time series; to be provided hourly c. Forecasts (one to several days ahead) as 1h time series; to be provided 6-hourly or daily; 7 Similar to this distinction of temporal extents, one might add a distinction in spatial extents: global and European. 8 Particularly for public information, as near as possible approaching real time, e.g. to be approximated by forecasts in previous hours and NRT. Data should be provided within the next hour. April 2009 Report of the GAS Implementation Group 21

22 d. Scenarios (several years ahead) as 1h/8h/1d/ annual statistics [and time series?]; to be provided annually. The GACS products can be described as combinations of these three categories: see Table 2. Table 2: CS Products for AQ: relevant combinations of pollutants, parameters and periods Parameters Period Columns, AOD 9 Concentrations Other Historic data (2000+) O3, NO2, aerosol, clouds; 3h time series and annual statistics O3, PM2.5, PM10, NO2, SO2, CO, HCHO Data on emissions, atmospheric processes, NRT O3, NO2, aerosol, clouds; 1h time series O3, PM1, PM10, NO2 Aerosols, clouds Forecasts Not relevant O3, PM10, NO2 Aerosols, clouds Scenarios Not relevant O3, PM10, NO2, SO2; 1h/3h/1d annual statistics Aerosols, clouds CS products on AQ may be used (i) directly, or (ii) as basis to elaborate more specifically tailored products (DS: find examples in section 2.3). Direct use of CS products (both by high-capacity users and by low-volume users as described in section 2.2) may be made for Scientific understanding and development: Model validation Emission estimates for inventories, natural events Alerts of major pollution events (natural and anthropogenic) Policy scenario development Large scale assessments by European institutions and agencies Large scale compliance checking with AQ thresholds at MS level; e.g. O 3, PM, difficult for NO 2 Public information on large scale for AQ (However, local information may be more relevant for public) Improving regional and global weather forecasting (e.g. clouds and fog, and air pollution radiative forcing) Climate forcing (CF) Services on climate forcing should include A. Monitoring of the state of the climate system (surface and upper air meteorology and composition) and its variability, and B. Integrated Global, European and regional concentration fields of key greenhouse gases (CO2, CH4 and related tracers, halogenated Hydrocarbons (CFCs, HCFCs,..) enabling determination of sources and sinks 9 The definition of time series of columns, AODs etc needs further consideration. April 2009 Report of the GAS Implementation Group 22

23 The emphasis is on essential climate variables (as a minimum) and GCOS requirements; High spatial and temporal resolution of the analysis is essential; Include water vapour and GHG cycles as well as different emissions sources. Where there is some information already available in an operational manner (i.e. clouds), the development of GACS in these areas should limit itself to the value added. As outlined above (section 2.4.2), the emphasis with respect to climate forcing should lie in a provision of ECVs variables as gridded fields, with a focus on atmospheric composition. Climate (Earth System) modelling will remain outside the scope of the GACS. Both the climate change as well as the air quality communities actually need very similar data, e.g. chemical composition, emissions, deposition fluxes, but for different purposes. Although the output of climate models is averaged over longer time spans, for the evaluation of many processes climate modellers need a fine resolution as well. Therefore, AQ and CF may be considered as a common issue within the GACS: While the user communities are different, the data requirements often overlap. In addition, the large component for AQ and CF should also provide elaborated products going beyond the provision of atmospheric composition data targeting the low-volume CS users such as policy makers. Annex 3.1 lists the envisaged products, their intended uses and the required parameters for AQ and CF Stratospheric ozone and UV services The GAS user workshop (December 2006) asked for the following topics to be included: Improved and sustained monitoring of the current status and trends in stratospheric ozone depletion; Routine provision of updated Ozone, UV and solar radiation maps and forecasts; Historic European UV and solar radiation records and mapping; See Annex 3.1 for the envisaged products Solar radiation (renewable energies) The GACS can provide added value for Solar Radiation regarding an EU-wide monitoring, and integration with other GMES services. Besides high-quality satellite-derived solar radiation, the renewable energy industry would benefit from improved quality and access to meteorological observations. Closer partnership between in situ observation networks and industry would stimulate expansion and qualitative enhancement of the observation infrastructure. The outputs envisaged to be provided by a CS for this theme are: Access to Satellite-derived (Meteosat) continental data of Global Horizontal Irradiance (GHI) and possibly also Direct Normal Irradiance (DNI); Access to in-situ solar radiation observations (global, diffuse and direct irradiance measured by meteorological services, BSRN, GEBA, and IDMP networks), including other meteorological parameters (air temperature, wind speed and direction, humidity, etc.); Prepared (filtered, resampled etc.) solar model data inputs comprising from relevant observational data and GACS AQ and CF CS outputs, e.g. ozone, water vapour, aerosols, atmospheric turbidity (as an alternative to water vapour and aerosols), cloud parameters, snow cover (NRT data needed); Genuine CS products such as time series, averages, maps. The satellite-derived CS output products are listed in detail in Annex 3. April 2009 Report of the GAS Implementation Group 23

24 The solar radiation theme is closely linked to other Atmosphere Core Services (such as Air Quality and Climate Forcing) as it depends on similar data, for the provision of high-quality solar radiation products (as inputs to solar radiation models) 2.5 Cross-cutting issues to other services The GACS has a need to acquire satellite observations delivered by other GMES services, specifically those related to land or ocean parameters. The latter two services will most probably need operational access to GACS products as well. Hence it is important to design data access procedures allowing easy implementation of data streams between the GMES core services. The HALO FP6-project focused on the data acquisition and data exchange requirements of the interacting parts of the three integrated projects MERSEA, GEOLAND and GEMS. Common data demands and direct product exchanges are discussed in detail in the HALO documents 10,11. The HALO recommendations are also applicable to the GACS and to the other GMES services. Cross-cutting issues and relevant dependencies between marine, land, emergency and the atmosphere service have been adequately identified, as follows: Sources and sinks: A Global Fire Assimilation Capability describing the biomass burning emissions into the atmosphere and the associated changes in carbon stock and land cover is needed. GMES should encourage the scientific development of ecosystem models incorporating the carbon cycle explicitly in the marine and land monitoring services. The three Earth system pillars of GMES (Land, Marine, and Atmosphere) should contribute jointly to the monitoring of carbon and nitrogen sinks and sources with the ultimate goal of supplying the factual basis for political decisions regarding climate change and air pollution. The GACS addresses source attribution from atmospheric observations; the Land and Marine CS model the terrestrial and oceanic stocks and fluxes. Reanalysis: As discussed above, GMES should include a new atmosphere re-analysis in support of the ocean re-analysis that will be produced by the marine fast track service. Interactions between services: The Land, Ocean and Atmosphere services each need to generate or acquire the best possible estimates of interfacial fluxes of momentum, radiation, sensible heat, latent heat and interfacial fluxes of a number of atmospheric constituents including carbon dioxide, nitrogen, water vapour and aerosol. It is important to have consistent high-resolution datasets with Land/Marine for cross-cutting issues needing all three, e.g. climate change. GMES marine and atmosphere monitoring systems should be encouraged to maintain close scientific and operational contacts with existing numerical weather prediction services so as to coordinate and further develop the multitude of interfaces already implemented between the pre-operational and operational systems; e.g. Ocean modelling requires atmospheric forcing fields, primarily wind stress; The systems exchange carbon dioxide as well as dust and sea salt aerosols; Ocean currents, waves, and winds interact to modify all the above mentioned fluxes; Atmospheric seasonal forecasts improve by using advanced marine seasonal forecasts; 10 HALO - Harmonised Coordination of the Atmosphere, Land, and Ocean IPs in GMES. Final Activity Report. ECMWF, Kaiser et al. HALO Final Scientific Report (Annex 2 of HALO Final Activity Report) April 2009 Report of the GAS Implementation Group 24

25 In addition: A transversal GMES element for Climate Change will require important inputs from the atmosphere service; in addition, other relevant ECVs must be delivered by Marine and Land services. Emissions from shipping may be envisioned for the future in connection with future services provided by GMES in the field of maritime safety & surveillance. The Emergency Response core service evolution envisions a facilitating of early warning systems (EWS). Model dispersion data sets are essential in the emergency response to chemical or nuclear accidents. Their provision should be considered within the GACS evolution in order to support the ERCS EWS. April 2009 Report of the GAS Implementation Group 25

26 3. The required in situ observational infrastructure In-situ is here defined in a broad sense to cover all non satellite observation data products, i.e. data from ground based in-situ measurements, ground-based remote sensing, balloon soundings 12, and routine aircraft. In-situ observation data are required as direct input to local, regional and European air quality models used for air quality forecasting or monitoring its long-term trends, for either assimilation or validation purposes. The boundary layer is not well monitored from space observation and many species are currently only accessible through collecting in-situ observations. In-situ observation data are also essential for monitoring of greenhouse gases and ozone. The following sub-sections contain a set of assessments and recommendations regarding the in situ observation infrastructure, bearing in mind needs of the GMES Atmosphere Core Service (GACS). However, the needs of future Downstream Services (DS), such as local AQ forecasting systems and the growing solar energy sector were not left aside either, in particular because some in situ observation capacities could feed both the GACS and these downstream services. 3.1 In situ observation needs for the GMES Atmosphere Core Service The GMES Atmosphere Core Service (GACS) provides products for four main application areas: (i) air quality, including long range transport of pollution, (ii) climate forcing, (iii) stratospheric ozone, UV and (iv) solar energy. These areas have different requirements regarding the need for in-situ data ranging from near real time (within hours) over rapid delivery (days) up to delayed mode of delivery (more than 1 month). A number of parameters coming from in situ observations should be fed into the GACS in order to ensure the above-mentioned requirements. A short overview is listed below, while the detailed description is attached to this report as tables in Annex 4. Air quality: Continuous surface station measurements for gaseous (O 3, NO, NO 2, CO, SO 2 ; if possible: HCHO, C 6 H 6 ) and aerosol mass concentrations (PM10, PM2.5), as well as pollen data; meteorological parameters (temperature, wind, humidity, pressure); Ground-based remote sensing (O 3, aerosol from LIDAR - several times a day/daily delivery, Aerosol optical depth from sky radiometers); Particulate matter (PM) composition (weekly, at least episodic for selected sites); Sondes (O 3 ) several times a day/daily delivery; Aircraft (O 3, PM, NO 2 ; possibly others like VOC); Emission data and deposition fluxes; Ancillary data (administrative units, land cover, elevation); Data quality information: detailed error estimates, specification of minimum detection limit; preliminary quality check at provider side for NRT data; Timeliness: NRT (not later than three hours later) for forecasting (at least hourly delivery); DM (delayed mode delivery) for validation (bi-annual); Geographical coverage: Europe, equally distributed number of stations, representative distribution of remote/rural/suburban/traffic stations. Climate forcing: 12 Such observations provide important knowledge in R&D phases April 2009 Report of the GAS Implementation Group 26

27 Surface concentrations, surface fluxes and vertical profiles/column for the essential climate variables as identified by WMO and GCOS, including water vapour, ozone and aerosol, and GHGs (CO 2, CH 4, and N 2 O) 13 ; High accuracy is essential for the quantification of long-term trends and for Kyoto protocol compliance modelling; Timeliness of data is of lower priority, although RD1 (Rapid Delivery, with delay ~1 day) might be useful for assimilation in models and for validation of satellite retrievals (in relation to Kyoto and Montreal protocol compliance); Data from the UTLS (O 3, H 2 O) are important for diagnosing climate change and its influence on air quality; The measurements must cover the global scale and require international coordination, e.g., via GAW. Stratospheric ozone and UV: Daily total column, vertical profiles, and UTLS measurements of ozone and aerosol (concentration and optical properties), plus total column and profile information on source gases (weekly) and surface measurements of UV radiation on a global scale; Accuracy requirements range from 1% for trends in TOC to 3% for NRT ozone mapping and prediction of UV radiation in order to assess compliance with the Montreal Protocol. Solar energy: Hourly or even 5-15 min values of global and direct normal radiation with an accuracy of 3% for global and 5% for direct normal radiation; NRT for network operation (Downstream Services); Meteorological data (temperature, wind, humidity, pressure) in NRT; Ancillary data (administrative units, land cover, elevation). 3.2 In situ existing observation infrastructure for GACS Main in-situ observation infrastructure available for the GACS include: 1. For air quality: National and regional air quality networks, which are mandated at EU level (EC, EEA, EIONET), operated by Member States and by regional and urban authorities, sometimes also by national meteorological services. The data collection scheme and the parameters measured/reported are based on legal requirements (EU AQ Directives and follow up daughter directives, national and regional legislation). The objective is assessment, compliance with limit values and information to the public. Data are sent to regional, national, and EC (AirBase) databases. Most sites are located in sub-urban, urban, or industrial areas. There are also a number of regional sites, which are often also measurement sites for the EMEP programme. EMEP (Co-operative European Monitoring and Evaluation Programme) was established under the LRTAP convention. The focus on EMEP is on long-range transport; therefore, in order to measure background concentrations, EMEP stations are located at rural sites. EMEP monitoring includes a large number of chemical and physical parameters to enable a complete understanding of transport, chemical conversion and deposition of pollutants at the regional scale. For the GAS in-situ infrastructure, the EMEP measurements of pollutant concentrations and wet deposition, emission inventories are important. 13 Phenological data are additional useful indicators of climate change; other long-lived greenhouse gases such as halocarbons, fluorocarbons, and sulphur hexafluoride needed when considering the ozone layer are also relevant for climate forcing.. April 2009 Report of the GAS Implementation Group 27

28 Near-real-time AQ data infrastructures in Europe relevant for GAS (EEA NRT AQ, EUSAAR, AirCE, Citeair, IAGOS) 2. The European UV network comprises about 40 stations with spectroradiometers and broadband EUV-biometers, operated by national agencies, who mostly (36) submit their data to the European EUV data base at FMI, Helsinki. QA procedures are established and further developed. There are about 100 additional regional stations operated by regional agencies. 3. Infrastructures and long-term research projects, which are supported by national research organisations with a long-term commitment and often co-funded by the EC: AERONET (aerosol column measurements by sun photometers coordinated by NASA), EARLINET (European LIDAR Network for vertical profiles of aerosol layers and optical properties, EU-infrastructure), EUSAAR (EU infrastructure project for advanced surface aerosol measurements), CREATE, CARBOEUROPE; NITROEUROPE, ICOS (EU infrastructure for measurements of GHGs (concentration and fluxes) and, MOZAIC, CARIBIC, IAGOS-ERI (EU infrastructure for routine aircraft observations, O 3, H 2 O, NO x, CO, CO 2, aerosol). 4. The European Aeroallergen Network (EAN) combines in-situ monitoring activities for biogenic allergenic aerosols, which are important for medical use. EAN currently receives operational monitoring information from 376 sites in 39 countries (also from outside Europe). The central database GAW-WDCA covers 213 pollen and spore types in total, with information content varying between the regions, climatic zones and contributors. 5. National Meteorological Services (NMS) collect, transfer and assimilate data from the global meteorological observing network in the framework of the World Meteorological Organisation (WMO) and through Global Telecommunication System (GTS). Data access and exchange are managed under Resolution 40 of the 1995 WMO Congress and the ECOMET agreement. The meteorological observing network is under re-assessment due to new needs with respect to more advanced higher resolution modelling. The GTS will, starting 2009, be superseded by the more open WMO Information System (WIS), which will have data centres open to the public. The European NMS coordinate their activities within EUMETNET, facilitating the contact at EU level. 6. Global Atmosphere Watch (GAW) coordinates world wide the total ozone (Dobson and Brewer) and the ozone sounding network. In addition, GAW stations measure greenhouse gases, such as CO 2, methane and N 2 O, reactive gases (NO x, surface O 3 etc.), aerosols and precipitation chemistry. The GAW network is coordinated by the secretariat of WMO. Since its inception in 1992, GAW has matured and developed into a programme with support from a large number of WMO Members. Twenty-four stations (comprising one or several individual sites) constitute the network of Global GAW stations. The remaining stations represent the GAW network of Regional and Contributing stations which add significantly to the global observing systems. More than 100 countries have registered approximately 700 stations with the GAW Station Information System (GAWSIS). As of March 2007, each of the GAW World Data Centres (WDCs) have registered anywhere between 80 and 400 stations. The surface-based observational network remains the back-bone of GAW. 7. NDACC, SHADOZ, TCCON and BSRN are independent worldwide networks that collaborate with and contribute to GAW. NDACC consists of approximately 70 stations world-wide for high-precision long-term measurements focused on free atmosphere. The network uses UV-Vis spectrometers, UV spectroradiometers, lidars, FT-IRs and microwave spectrometers to measure columnar contents and profiles of a large number of atmospheric constituents. SHADOZ (Southern Hemisphere Additional Ozone sondes) is a subset (12 active sites) of the GAW ozone sonde sites that are coordinated by NASA. It has its own data centre. TCCON (Total Carbon Column Observing Network) is a network of 10 ground-based Fourier Transform Spectrometers recording direct solar spectra in the near-infrared spectral region. From these spectra, accurate and precise column-averaged abundance of CO2, CH4, N2O, HF, April 2009 Report of the GAS Implementation Group 28

29 CO, H2O, and HDO are retrieved. TCCON provides an essential validation resource for the Orbiting Carbon Observatory (OCO), SCIAMACHY, and GOSAT. BSRN (Baseline Surface Radiation Network) is a WCRP/GEWEX project aimed at detecting important changes in the earth's radiation field at the earth's surface which may be related to climate change. At about 40 stations in contrasting climatic zones, solar and atmospheric radiation is measured with instruments of the highest available accuracy and with high time resolution (1 to 3 minutes). 3.3 Shortcomings of the existing In situ observation capacities Geographical coverage and adequacy of the monitoring activities Air quality The inadequate monitoring and geographical coverage of parameters for air quality assessment (in particular surface PM2.5, CO and VOCs) is an issue which should be addressed by optimization of the spatial distribution of air quality stations. Monitoring on the regional/rural scale should be in compliance with the recommendations of the EMEP monitoring strategy in terms of station density and parameters to be measured. There is in particular a need for additional sites in the Balkan area, Mediterranean, and Eastern Europe as priority regions. The number of sites for the measurement of ozone, NOx, and CO should be increased there so that it is in compliance with the recommendations of the EMEP monitoring strategy in terms of station density. More regional sites for the measurement of VOCs are needed, and more sites with PM2.5 and PM1 would be useful. In some regions of Europe, in particular in the south and south-eastern part, more PM10 measurements are needed. Further research, particularly modelling, should aid the strategic positioning of AQ measurement stations. Climate change The infrastructure for monitoring GHG (CO 2, CH 4, N 2 O) is inadequate. While there are many monitoring stations in Europe, particularly for CO 2, there is insufficient coverage in remote marine areas. There is need for relocating monitoring stations to European owned territories, particularly over the southern ocean 14. As to phenological data, there is a very low coverage in most parts of Europe. An adequate monitoring infrastructure needs to be set up to address the role of aerosols and clouds, which generate (see IPCC reports) large uncertainties in determining the current anthropogenic climate forcing. EARLINET and especially a limited subset of supersites are instrumental to this purpose in Europe. Similar initiatives exist in the USA (the ARM-sites) Stratospheric ozone Many European nations perform routine measurements of total ozone with Dobson and Brewer instruments in support of the Vienna Convention for the Protection of the Ozone Layer. Ozone profile measurements are also carried out at several stations. It is usually considered a national obligation to carry out these measurements. However, compared to the global coverage, Europe is again over-sampled. Dobson instruments that are complemented by a Brewer instrument at the same station should be relocated to data sparse regions, such as Asia, Africa and Latin America. Coordinated approach is needed among European countries to agree on how the station density could be homogenised globally. 14 High latitude regions should also be mentioned April 2009 Report of the GAS Implementation Group 29

30 3.3.2 Sustainability of the observation capacities There is a limited sustainability of in-situ infrastructure, in particular for vertical profiles (for ozone, aerosol, CO, NO x, CO 2 ), which are often provided and operated by national research institutions. For air quality, the key activities are derived from existing long term structures (monitoring in support of AQ Directive, EEA, EMEP, GAW, HELCOM, and OSPAR) as described in official documents, e.g. the monitoring in the EU description, the EMEP strategy, and the GAW strategy. However, these structures deliver mostly surface in-situ data and vertical ozone content. The important requirements for vertical profiles (ground based and aircraft measurements) are presently fulfilled by weaker structures and should be consolidated for GMES purpose. As regards climate forcing, data from the UTLS on O 3 and H 2 O, as well as vertical profiles of GHG (O 3, CO 2, CH 4 ) and aerosol properties, have similarly been provided mainly through research projects, some of which are currently transformed into European research infrastructures under the support of Member States. Most important for GMES are those research-type monitoring structures, such as AERONET, EARLINET, EUSAAR, IAGOS-ERI, ICOS, and NDACC/TCCON, which have a proven longstanding record and are sustained by institutions with a strong commitment but not necessarily for very long term operational activities. Sustainability of some key infrastructure components for GACS and related activities, including the AERONET central European calibration and maintenance site, the EARLINET NRT collection and operation, EUSAAR, ICOS, the support for IAGOS-ERI operation, the GAW/NDACC capacity building/training for NRT, and support for its long term operation, should be ensured. In the long-term, the sustainability of observations from regular aircraft measurements should also be ensured. It is particularly important to expand routine aircraft observations to remote areas of the Northern Hemisphere and to the Southern Hemisphere (as planned in IAGOS). Due to the need for long term contracts with airlines and the long lead times for certification, routine aircraft observations cannot be guaranteed on the basis of research projects, but require a long term perspective Availability of data Air quality There is insufficient timeliness of data availability compared to GACS needs, e.g. NRT data for AQ forecasting and solar power. It is recommended to establish common and sustainable mechanisms for the provision of NRT data required by GACS, in particular for air quality forecasting and solar energy, using existing infrastructures established by EEA or forthcoming structures, such as the WMO WIS, or EMEP initiative. The provision of NRT AQ data, in particular of PM2.5, is needed for assimilation in models operated by GMES core and downstream services... Another issue related to air quality is an inadequate availability of NRT meteorological data to services. The NRT meteorological data should be made more easily available for local/regional air quality modellers on the basis of detailed service requirements. Ozone and UV Ozone sonde data from a number of European stations are gathered in NRT at the Norwegian Institute for Air Research (NILU) and passed on to ECMWF. The existing routine for NRT collection of European ozone sonde data should be expanded to include all ozone sonde stations worldwide. Some short-term support might be needed to implement routines that once established would run with a minimum of effort. There is no such NRT facility for total ozone, although some stations (only one in Europe) submit total ozone data to the WMO GTS system. A system to collect total ozone data in NRT and make it April 2009 Report of the GAS Implementation Group 30

31 available to the GAS Core Service should be established. This system should encompass stations world wide. It should make use of WMO s GTS (WIS in the future). 15 The NRT UV data (both scans and EUV/UV Index values) are available only in regional data bases and information systems. The data are not collected or shared in the EU scope. Except for some pilot experiments in the past, a system for NRT and RD (Rapid Delivery) UV data exchange data does not exist at EU level. Same as for total ozone data, a system to collect UV data in NRT and make it available to the GACS should be established. In addition, The European data centre for UV (EUVDB) does not serve for all European stations. Because of limited resources, the UV calibrations with the new calibration unit developed in the frame of the QUASUME project are performed only occasionally. All European UV radiation data should be made available through a single focal point. Solar radiation NRT solar radiation data are needed for grid operation. The data are used (i) locally, (ii) for online quality check of satellite data, and (iii) as input for forecast products. Solar radiation measurements collected by national meteorological services should be available in NRT, preferably at 5-15 minutes intervals (depending on the application). GEOmon and its follow-on The GEOmon (Global Earth Observation and Monitoring of the atmosphere) project, co-funded by the EU FP6, was originally planned in support of GEOSS, for building an integrated pan-european atmospheric observing system of greenhouse gases, reactive gases, aerosols, and stratospheric ozone. Ground-based and air-borne data are gathered, harmonised and analysed for supporting the quantification and understanding of the atmospheric composition changes. GEOmon is seen as an important contribution for preparing the operational GACS in-situ data management in terms of databases and NRT data delivery, and for establishing the data structures required by GACS. Several functionalities developed by this project should be sustained, either through direct integration in the GACS architecture, or through external functionalities interfaced with the GACS system. 3.4 Coordination mechanisms The in-situ observation provision to the GACS requires several levels of coordination linked to: The long term availability of the in situ observation infrastructure required by GACS, and the related data access conditions which should be addressed at governmental and institutional levels: For European capacities: between the Member States and the EU For international capacities: through the existing frameworks and forums, including the GEO and WMO, or through bi- or multi-lateral approaches when relevant. The technical coordination for data collection, assembly and provision to the GACS, which should be addressed by technical entities with the appropriate level of coordination. This section will be more focused on technical issues. Infrastructure coordination Currently both the stratospheric Ozone and UV data that originate from EU networks are managed individually by national institutions; they are not subordinated to joint EU reporting obligations. Longterm and regular ozone observations are co-ordinated and supported by the GAW facilities and the NDACC initiative in Europe. The UV observations are mostly controlled under EC funded R&D projects. 15 The archiving/availability of non-nrt total ozone and profile ozone data should also be addressed. This dataset is the basis for trend analyses in the framework of the Montreal protocol. April 2009 Report of the GAS Implementation Group 31

32 It is then recommended that, considering the GACS implementation and related requirements, a European coordination for the observation and data management infrastructure for O3 and UV should be set up. It would serve as a European contribution to the GAW/IGACO and GEO programmes and would also represent an asset for downstream services. Research-type monitoring structures, such as AERONET, EARLINET, EUSAAR, IAGOS-ERI, ICOS, and NDACC/TCCON, have a proven longstanding record and are sustained by institutions with a strong commitment. To the extent possible, it is recommended that research monitoring infrastructure should be coordinated with or made part of the EMEP/GAW joint supersite arrangement. Data quality and standardization The lack of interchange between networks results in the absence of common Quality Assurance (QA) standards, common data formats and conversion procedures for data used in different networks and for different purposes. There is a clear need for traceable and harmonised data quality across various networks. It is recommended to define or apply common international standards for different data, preferably by expanding or implementing EN or ISO standards as it is already the rule in the meteorological community. From the short-term viewpoint, there is a need for establishing NRT procedures, including QA, for regular LIDAR profiles of aerosol and for establishing a European QA centre for the European sun photometer network (AERONET), which is currently mainly sustained by NASA. The data quality of the Dobson, Brewer and sonde networks is secured through GAW calibration centres, but the sustainability for these is variable. These calibration centres should be secured; since they look after the whole European region (the whole world for the ozone sonde calibration centre) this should be a European responsibility and not only rely on a few nations voluntary efforts. A sustainable assistance to a central calibration facility for European UV radiation stations is necessary. In summary, the EU should support the operation and further development of central European facilities including: Ozone and UV calibration and mapping centres, EMEP, AERONET and EARLINET calibration, The provision and storage of quality-controlled long-term reference data sets for open access by the GACS and GMES users. Databases It is also recommended to support the harmonisation of air quality and atmospheric chemistry databases, based on activities such as EMEP, GAW, CREATE, AirBase, as well as national and regional networks in order to harmonise processing methodologies, data formats, quality assurance procedures and NRT data dissemination for GAS. As a long-term goal, it is recommended to implement a common and interoperable management of atmospheric constituent databases. An improved European high resolution air quality emissions database, building on existing infrastructure such as EMEP and EPER, as an input for air quality modelling is needed and should be supported. Finally, error estimates and site descriptions (metadata) are very important for assimilation modelling. Data and metadata formatting should be adopted in line with the INSPIRE process (Air SDIC) to enable proper data filtering, interoperability and metadata information defined by the Air SDIC (Data Exchange Group) under EC DG Environment chairing. In this context, the added-value of GEOmon-like approaches for data quality and harmonization and for database coordination and management should be taken advantage of and sustained through in the long term. Moreover, a coordination body for the GACS in situ observation infrastructure (e.g. April 2009 Report of the GAS Implementation Group 32

33 embedded in the GACS coordination structure) should be set up for managing the technical activities and the various interfaces and linkages between the various actors. Regarding coordination issues, the technical and institutional roles and functionalities covered by EEA, SEIS and the INSPIRE framework and its related data management infrastructure, should be clarified, and their consequences and impacts on the GACS governance and architecture identified. Guidance on these issues should be provided by the In-Situ Observation Working Group. 3.5 Funding and data policy issues A coordinated European approach, with greater liaison between funding sources and implementing entities, is essential to streamline funding and thereby provide significantly increased stability for observation infrastructure, data quality and the provision of observation data. Current funding is provided through regional, national, governmental, European and private authorities with different interests. In most cases, long-term funding is not available; monitoring activities must rely heavily on the successful renewal of two or three year contracts by individual researchers. The funding stream for monitoring is in some cases (but not for meteorology-like observations) the same as for interest-driven research despite the different nature and aims of the work involved. In recent years, research funding organisations have put an increasing emphasis on innovative and wealth creating science. Atmospheric monitoring does not fall in these categories per se, but rather contributes significantly to policy and public debate through the extension of established, high quality records and increased spatial, temporal and species coverage. The implementation of an operational GACS requires the availability of European atmospheric monitoring systems which should be sustainably supported as part of this operational activity through appropriate funding mechanisms. Many in-situ services needed for GAS still depend on discontinuous, cyclical funding and additional EU R&D funding for specific objectives. A great number of EU research projects have included an insitu data component which involves support for collection or acquisition of data from across member states or standardisation of data collection and management processes. The data, the relationships developed with data holders and data processes become part of a capital which helps the consortia to secure further work. As a consequence, EU funded research with its reliance on cyclical funding can reduce in situ availability (as it stays within certain consortia), or is lost as funding is discontinued. Organizations financing models have been adapted to the funding cycle and requirements and this creates obstacles to data access, which ultimately undermines the development of GMES. For in-situ observation networks, a transition of funding from research projects to long-term sustainable schemes for the upgrade of observing systems, services, and the set-up of a data management system are highly recommended. To fix the orders of magnitude for air quality, it is estimated that about 3000 AQ monitoring stations exist in Europe (without research networks), with running costs of k /year/station, and investment costs of about 10 k /yr/station, which results in total costs of M for the standard AQ monitoring stations in Europe. It has to be emphasized that the k /year/station are the costs for AQ stations that measure standard AQ components and are relatively easy to cover. The costs for background monitoring stations (e.g. EMEP stations) that are more remote and/or measure special components can be much higher (i.e k /yr). The European operational ozone and UV monitoring network is almost fully supplied from national resources - mostly by the meteorological services, universities, atmospheric research institutions or by grant agencies. A joint and sustainable international funding system has not been established for O3 and UV In-situ infrastructure in Europe. Ozone observations in several newly adopted EU countries are occasionally supported by the GAW programme, by the EC funded research projects or by EU partner institutions. The existing joint European GAW technological facilities (RDCC-E, RBCC-E, WCCOS) that assist the monitoring stations are also mostly funded by national agencies. For April 2009 Report of the GAS Implementation Group 33

34 sustainable function and further development of these facilities an additional funding in the GMES framework is needed. Some ozone measurements like the airborne, LIDAR/microwave measurements or special satellite validation missions are supported by temporary R&D projects. Concerning data policy, the situation is not homogeneous, as illustrated by the case of total ozone and UV data. About 70 % of the European stations provide their provisionally quality controlled total ozone data operationally to the WMO World Ozone Mapping Centre. The derived products are freeavailable to users. The ozone and UV data files deposited in databases of some specific programmes/projects (e.g. NDACC, BAS, SHADOZ, SUVDAMA/SCOUT) are not fully accessible to users because of different levels of restrictions given by the projects agreements. Within Europe, the existing legal reporting frameworks (e.g. AQ directives) should be used to provide the framework to request (additional) in-situ data. Specific thematic legislative acts, such as INSPIRE, as well as SEIS, can be leveraged to achieve the results foreseen to be needed for GMES services. Mandates agreed at a European level by the Group of Four 16 and other existing European data centres should be used to provide a basic framework around which the European dimension of in-situ data can be built. 17 The availability of near real time surface weather data is a special case and specific bilateral agreements have been established in several countries. It is recommended that the access to meteorological data in the context of GMES has to be clarified, and organisations have to be mandated to negotiate and resolve limitations on non-research use of meteorological data for the whole of the EU. Furthermore, it is essential that GMES funding of networks/infrastructures must be conditional to open data access. In more general terms, a governance approach is needed for the in-situ observation component required by the GAS. This approach should involve the relevant Member States and European authorities mandated for making arbitrations, deciding priorities and long-term commitments about the long term availability of in-situ observation infrastructure and related data processing and management facilities, and their evolution. 3.6 International cooperation issues International cooperation is mandatory for GACS because it requires global in situ observation data which cannot be collected only by European infrastructure. It induces that international cooperation mechanisms should be used for the coordination of in situ observation infrastructure and exchange of data. It was recognized that there is too little cooperation between existing networks and data centres. In several countries, national agencies have limited access to data from regional networks. Furthermore, a diversity of data access policies and a large number of specific bilateral data exchange agreements exists. In addition, there is limited access by organisations and networks to in-situ data, e.g. only to partial data-sets or aggregated values. In particular, a clear need for access to meteorological in-situ data is found. On an international level, coordination is required between European networks and other non- European networks, e.g. in the USA and Asia (for AQ etc.). Important topics are exchangeable data formats and compatible (known) instrumentation, as well as calibration / validation and QA procedures. Monitoring from commercial aircraft (IAGOS) has the important advantage of providing worldwide information which is based on a common set of instruments, is based on the same quality standards, 16 Made up of DG Env, EEA, Eurostat, and JRC. A 2005 technical agreement on Environmental Data Centres identifies roles in relation to DG Environment s information needs. 17 The EU's EEA is mandated to coordinate in-situ data with the support of its network (EEA/EIONET) in countries. In this context, it is advisable to extend the Exchange of Information Decision (97/101/EC) to NRT data exchange. April 2009 Report of the GAS Implementation Group 34

35 and is provided through a single database. The leading role of Europe in this sector should be maintained and coordination should be sought through IAGOS with other routine aircraft projects, e.g., in Japan and the USA. Guidelines for defining the contribution of European observation infrastructure to international observation capacities and networks, and the related coordination and funding approaches should be defined at the GMES governance and management levels. These guidelines should drive the implementation approaches for the relevant GAS in-situ observation infrastructure and related capacities. 3.7 Research and Development Continued research and development is an essential component of a healthy in situ component of the GAS. Several orientations are supported: Develop new in situ measurement techniques, including ground based remote sensing and aircraft observations. Concerning AQ, better and more detailed methods for aerosol monitoring are called for from the public health perspective. Concerning climate change, there is a strong need to better monitor aerosols and clouds and their role in the radiation balance. More accurate and regular measurements of the increasing amount of stratospheric water vapour are necessary for the ozone layer and UV. Also, completely new approaches might be explored, like the use of a large number of relatively cheap, low-quality sensors coupled through Internet. Improve comparison and characterisation of existing monitoring equipments, to better assess the obtained datasets, including measurement errors, strengths and weaknesses. This will lead the way to further harmonisation and integration. find and develop the best ways to make all measurements available in (decentralised but transparent) databases, in such ways that data use is facilitated maximally. This includes the NRT and computer-to-computer access that is necessary for a number of applications. Initiate studies to achieve the best balance (both from economic and scientific point of view) between space based and ground based monitoring, and to determine the optimal ground based networks for different components, in terms of density and locations. Increase accuracy and resolution of emission databases; Finally chemical transport models are starting to assimilate ground based monitoring data in real time, allowing more accurate forecasts and better analyses. Research is needed to find out the best ways to do this, with implications both ways: for the model and for the monitoring infrastructure. 3.8 Summary of conclusions and recommendations The GACS scope and its related information provision leads to requirements for in-situ observation data for the whole atmospheric layer (from near-surface to upper stratosphere) with European to global coverage and timeliness ranging from near real time (within hours) over rapid delivery (days) up to delayed delivery mode (more than 1 month). A number of observation capacities already exist, based on national and regional observation infrastructure, and in many cases structured at European (e.g. EMEP for air quality) or international (e.g. through the WMO Global Atmospheric Watch for the free atmosphere) levels. Recommendation 1: observation infrastructure availability The existing in situ observation capacities relevant for GACS, mainly based on infrastructure operated at national level, must be sustained in the long-term by the Member States, and the European and international structure of these capacities should be consolidated by the European Union. April 2009 Report of the GAS Implementation Group 35

36 Commitments from the Member States and the EU are needed in terms of: Improvement or optimization of spatial coverage For the air quality station distribution, especially over the Balkan and Mediterranean areas and Eastern part of Europe Sampling of GHG observations, especially over marine areas Relocation of stratospheric ozone observation capacities in Asia, Africa and Latin America Sustainability of observation infrastructure For key air quality capacities mainly operated by Member States For the consolidation of research-type monitoring capacities linked to GHG observation (e.g. ICOS), ozone layer (e.g. NDACC), tropospheric aerosols (e.g. AERONET and EARLINET) and aircraft measurements in the troposphere (e.g. IAGOS), which in many cases contribute to international observation networks. Recommendation 2: data management and access A critical requirement is linked to the NRT data provision to the GACS, especially for air quality, ozone and UV, and solar radiation. There is a need to establish mechanisms and related systems enabling this data provision, encompassing the data delivery from observation infrastructure, the data management and its quality control. The creation of a European high resolution air quality emissions database, building on existing infrastructure such as EMEP and EPER, as an input for air quality modelling, should be supported. For tropospheric and stratospheric observation management, functionalities such as: Single-point portal enabling to connect with distributed databases, Harmonisation of multiple-source datasets, including inter-calibration, common standards for metadata and data currently provided through research projects such as GEOmon must be sustained for GAS, and for some of them integrated in the GAS architecture. Access conditions to meteorological data for air quality and solar energy downstream services should be clearly established. Recommendation 3: coordination issues European coordination is needed regarding both institutional and technical issues. At institutional level, there is a need for defining approaches involving the Member States and the European Union and addressing: The co-management of the observation infrastructure and data provision, inducing commitments about their long-term availability The co-funding issues The international cooperation and integration issues The technical coordination activities include observation infrastructure operation and data management. GAS requires in particular: Consolidated and integrated procedures for operating the observation capacities, including research monitoring systems, e.g. as part of EMEP Data quality and standardization, including calibration and validation activities April 2009 Report of the GAS Implementation Group 36

37 Data management and dissemination The international framework, e.g. CLRTAP, WMO and GEO, represents a key driver for the European coordination approach, especially regarding calibration and validation, data standards, The institutional and technical functionalities covered by the EEA, the Shared Environmental Information System and INSPIRE, and their impact on, or linkages with, the GACS architecture, management and governance should be clarified. Guidance on these issues should be provided by the ISOWG, after consultation with the GACS Implementation Group and potential GACS providers. Recommendation 4: funding issues As much of the GACS relevant in situ observation infrastructure will be provided and operated by Member States, commitments from these Member States are needed about: The long-term availability of in situ observation infrastructure required by GACS, Related data access mechanisms (including sustainable data delivery conditions). The EU funding support should in particular be focused on: The gap filling in observation infrastructure, enabling e.g. relocation of observation capacities and development of observation networks in e.g. Eastern part of Europe or outside Europe, The availability and operation of Pan-European observation infrastructures that cannot be associated to individual member states, The European contributions, in particular through European capacities, to international observation networks and data management systems, Technical (e.g. Cal/Val and data management facilities) and institutional coordination activities. Recommendation 5: R&D A steady support to research in needed in order to Develop new in situ measurement techniques, including ground based remote sensing and aircraft observations, and explore various organizing scheme with the benefit of improved communication technology; Improve comparison and characterisation of existing monitoring equipments; Find and develop the best ways to make all measurements available in (decentralised but transparent) databases. Initiate studies to achieve the best balance (both from economic and scientific point of view) between space based and ground based monitoring, and to determine the optimal ground based networks for different components, in terms of density and locations. Increase accuracy and resolution of emission databases; Stimulate joint efforts of in situ observation and modelling communities, in order to achieve increasing and successful assimilation of in situ observations in numerical chemistry forecast models. The EU funding support should in particular be focused on essential R&D for monitoring networks addressing global environmental issues, or environmental issues at a supra-national scale April 2009 Report of the GAS Implementation Group 37

38 4. The required space observational infrastructure In the following, the recommendations regarding the space infrastructure are summarised based on the overall report (available on a stand alone basis) produced by WG4. These recommendations have been forwarded to the space agencies ESA and EUMETSAT in order to guide their considerations of user requirements. A relevant workshop at ESTEC, 25 th April 2008, was held between ESA, EUMETSAT, the EC and IG/WG4 representatives in order to discuss these findings. Funding for S-4 and S-5 is earmarked in Segment Space observation needs for the GMES Atmosphere Core Service The GMES Atmosphere Core Service (GACS) provides products for three main application areas: (i) air quality, including long range transport of pollution, (ii) climate forcing and (iii) stratospheric ozone, UV and solar energy. These products cover short (including when appropriate near real-time) to long term (especially through reanalysis) information needs. The specific parameters to be derived from space observation requirements for each of the GACS application areas include: 1. For air quality: (vertical profiles of) 18 particulate matter (PM), ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO) and sulphur dioxide (SO2), with hourly sampling during daytime with specific focus over the European area and its neighbourhood 2. For climate forcing: vertical distribution of tropospheric Essential Climate Variables as identified by WMO and GCOS, including water vapour, ozone, aerosols (optical and chemical properties), cloud optical properties and greenhouse gases with focus on carbon dioxide (CO2) and methane (CH4), with global coverage 3. For ozone, UV and solar energy: total content and profiles (especially in the upper troposphere and stratosphere) of ozone, plus information on water vapour, active nitrogen components, nitrogen reservoir and source species (NOx, HNO3 and N2O), active halogens and halogen reservoirs, aerosol and cloud optical properties and methane with global daily coverage and vertical resolutions ranging from 0.5 to a couple of km. In addition, also needed for all activity areas: 4. Access to the full range of data utilized in operational numerical weather prediction 5. Information on fire activity. As the availability of well documented long time series of atmospheric composition parameters (mainly derived from reanalysis) for climatology purposes is of major importance for GACS, the continuity of space observations with stable operational performances and quality is considered as the highest priority. 4.2 Space infrastructure for the GMES Atmosphere Core Service The fulfilment of the GACS requirements for space observation is linked to the availability of several types of missions, including: 18 Vertical profiles in the troposphere are needed for most of the species of interest except NO2 for which it can be assumed that the major part is localized in the PBL. However, vertical profiles are in many cases not feasible, especially not for the GEO UVN and the precursor and only partly for the Sentinel 5. The possibility to achieve vertical profiles is a matter of combined techniques; EO measurements, in-situmeasurements and advanced 4D-Var assimilation in models. April 2009 Report of the GAS Implementation Group 38

39 For the short-term, European and international satellites or payloads already operated or planned in the near future, For the medium to long-term, continuity of current observation capacities or implementation of new ones. Many observation capacities relevant for GACS have no redundancies, neither at European nor at international levels. In order to mitigate this weakness: Missions initially designed for research purposes and whose observation performances have been validated could be used in the operational context of GACS All possibilities for maximizing the observation potential, including complementary or shared infrastructures with non European institutions, need to be explored. Major features of the present /anticipated space infrastructure are illustrated by charts in Annex Existing European observation capacities It is recognized that: The "atmospheric chemistry payload" of ENVISAT, including the SCIAMACHY, MIPAS and GOMOS instruments, is crucial for the characterization of atmospheric composition throughout the troposphere and stratosphere, The IASI instrument onboard MetOp/EPS makes a substantial contribution to global monitoring of many atmospheric species which is crucial for many GACS components, The GOME-2 instrument onboard MetOp/EPS and the European OMI instrument onboard NASA s AURA enable to derive column characteristics for e.g. O 3, NO 2 and SO 2, The MSG SEVIRI, MetOp/EPS AVHRR-3, ENVISAT/AATSR&MERIS and PARASOL instruments contribute to the characterization of aerosols and clouds, solar radiation and in some cases fire. It is accordingly recommended to: Maximise the lifetime of the ENVISAT atmospheric chemistry instruments and of the AATSR and MERIS instruments 19, Deliver operationally to GACS the MetOp/EPS and MSG relevant observations. More specifically, for the GOME-2 instrument onboard MetOp/EPS, it is recommended to: Explore the feasibility for the two remaining MetOps to provide GOME-2 with increased performance, in order to achieve improved spatial sampling Future European observation capacities UV-visible-near and shortwave infrared spectrometers GMES Sentinels 4 and 5 payloads are proposed by ESA in order to address the atmospheric chemistry observation collection in the timeframe and to initiate a new era of operational missions in heritage of successful previous and current demonstration missions. The two spectrometers UV-visible and near-infrared (UVN) in geostationary (GEO) orbit for Sentinel-4, and UV-visible-near-infrared and shortwave infrared (UVNS) in low-earth (LEO) orbit for Sentinel-5 should primarily address the needs for climate forcing gases 20 and its precursors and 19 A similar recommendation (see the section devoted to international issues) holds for OMI, an ESA third party mission and also a Dutch-Finnish instrument; OMI might be seen as part of the existing European observation capabilities.. 20 It is understood that CO2 and CH 4 are very important ECVs. SCIAMACHY and IASI as well as OCO and GOSAT will allow preparing for some initial services. Even with SCIAMACHY (not fully optimised for CO 2/CH 4, especially with regard to spatial resolution) there is already added value demonstrated. Thus Europe could significantly contribute to atmospheric CO 2 and CH 4 monitoring from space. April 2009 Report of the GAS Implementation Group 39

40 basic needs for aerosol monitoring, as well as high temporal/spatial resolution measurements of tropospheric composition for application to air quality. Additionally, EUMETSAT has started preparatory activities for its future geostationary and polar missions, i.e. MTG and Post-EPS, to be launched by 2017 and 2020 respectively, where identified application areas include ozone layer and surface UV monitoring & forecasting, composition-climate interaction, and air quality monitoring & forecasting. The use of MTG and Post-EPS satellites as platforms for implementing the Sentinels 4 and 5 payloads is a major option under consideration in the GACS perspective. In this context: The Sentinel-4 (GEO) is a new observation capacity which should be handled by Europe. It should especially improve the time sampling (as needed based on GACS requirements) and then increase the frequency of cloud-free observations, which is important for highly reactive gases such as NO 2 and SO 2. Embarking the Sentinel-5 payload onboard Post-EPS would allow sustaining global monitoring of atmospheric composition established by GOME-2 / IASI operationally on MetOp, by OMI on EOS-Aura and by SCIAMACHY /ENVISAT to retrieve greenhouse Gases. This plan would however clearly lead to a significant data gap for the LEO observation capacity after ENVISAT and USA's AURA lifetimes, i.e. in the 2010 (2012) 2015 (2020) timeframe, in particular for data in support of air quality applications and tropospheric climate gases and its precursors UV-visible-near and shortwave infrared spectrometers It is accordingly recommended to develop and deploy the following new capacities: A UVN spectrometer (Sentinel-4) to be embarked on MTG-S To serve needs of regional operational Air Quality applications requiring dense sampling, in Europe, To allow optimal use of the synergies of an UVN on MTG with the FDHSI (clouds, aerosol) and IRS (tropospheric O 3 and CO) instruments. Around 2014, a UVNS spectrometer (precursor of Sentinel-5) in a polar orbit complementary to MetOp, with afternoon equator crossing time To serve global needs of Air Quality applications as optimal addition to MetOp and the USA's NPOESS, To add SWIR observations to sustain & improve on SCIAMACHY-nadir/SWIR monitoring of greenhouse gases and CO near-surface column concentrations, To bring forward by 5 years deployment of the first Sentinel-5 payload, hopefully achieving overlap with ENVISAT, To maintain global coverage, and improve upon the spatial resolution provided by OMI (on the AURA mission). A UVNS spectrometer (Sentinel-5) to be accommodated on Post-EPS platform, alongside Infrared Spectrometer (IRS) and Visible-Infrared Imager (VII) Concerning the Sentinel-5 precursor, it is noted that deployment on a 3 rd party platform 21 or through a national payload contribution would minimize cost. While no priority has been currently established between the GEO and LEO mission lines, some boundary conditions (observation gaps, specific milestones linked to MTG and Post-EPS developments) should drive their implementation. 21 Candidate 3rd party platforms to accommodate launch ~2015 could potentially include NPOESS and other national agencies and need not exclude Sentinels 1-3. April 2009 Report of the GAS Implementation Group 40

41 In order to synchronise the MTG and Sentinel-4 as well as Post-EPS and Sentinel- 5 programmatic agendas, it is then recommended to ESA and EUMETSAT to further harmonise their respective requirements on these projects Thermal infrared spectrometers for atmospheric chemistry GACS requirements also include needs for thermal infrared spectrometers to sound the troposphere for atmospheric chemistry purposes and provide profile measurements of CO, ozone, HNO 3, CH 4 and volcanoes SO 2 and to complement Sentinels 4 and 5 observations. As thermal infrared instruments are already part of the core payload of MTG and Post-EPS, as they are the baseline meteorological instruments to sound temperature, humidity and winds, specific recommendations are not provided here. But these instruments will also provide important information for air quality only if the instrumental specifications are optimized accordingly. It is thus recommended that the instrumental specifications (noise, spectral resolution, and pixel size) are also optimized to answer the GACS air quality and climate requirements Limb mission The Upper Troposphere/Lower Stratosphere (UTLS) region plays an important role in the Earth s climate system, particularly in the tropics and north polar region: observations of trace gases in this region at high vertical resolution are mandatory for understanding the effects of climate on global ozone and the water vapour budget, and in turn the effects of these greenhouse gases on climate, ozone and large scale mid-to-upper troposphere air quality issues. Millimetre-wave limb-sounding (MMW) technique provides key trace gas profiles in the upper troposphere/tropopause region, and would also enable to resolve the lower troposphere through combination with Infra-Red Sounding and UVNS nadir measurements. Noting the absence of MMW and IR limb profiling capability for the UTLS region in the post-envisat/aura/odin era, it is recommended to address this key deficiency for GACS and to identify solutions, possibly through international cooperation, to avoid discontinuity of these observations Other European operational observation capacities The interest of ESA Sentinel-3 and of relevant MTG and Post-EPS instruments for the characterisation of aerosols and clouds (and fires) deserves to be emphasized Ground segments and interfaces with GACS Ground segment requirements and interfaces with the GACS are not detailed in this report, and will also be addressed through the GACS architecture. It is however recommended that: Direct interfaces between the operators of GACS data management and assimilation systems and the relevant space mission operators, including European and non-european (e.g. NPOESS) ones, should be implemented. Use of existing data dissemination infrastructure, such as EUMETCast and GEONETCast, should be encouraged, especially for GACS near real time applications, Existing assets such as the Climate Monitoring and Ozone / Atmospheric Chemistry SAFs established by EUMETSAT contribute to the GACS provision as needed. April 2009 Report of the GAS Implementation Group 41

42 4.3 International cooperation issues As mentioned previously, international cooperation is of crucial importance for maximising the space observation capacities for GACS and for complementing the European capacities, which have no redundancies. Regarding international coordination processes, it is recommended that an early and clear planning from Europe be used to build global cooperation agreements for operational systems in the frameworks of WMO, CEOS and GEO, following the successful model of meteorology implemented in Europe by EUMETSAT. More specifically, it is recommended To engage a formal dialogue between Europe and the United States relevant agencies to: Emphasize the interest of Europe for existing GACS relevant USA missions, and especially AURA (noting the European instrument OMI onboard AURA) and those of the A-Train, and its support to the maximisation of their lifetime; Point out as well the interest of Europe for future GACS relevant USA missions, including the Orbiting Carbon Observatory (OCO), and OMPS limb instrument for ozone profiling in the stratosphere (with limited capacity for the UT/LS); Address possibilities for cooperation on future operational atmospheric chemistry missions, especially for LEO and GEO UVN(S) spectrometry and MMW and IR limb-sounding capacities. To engage similarly dialogues with countries such as e.g. Canada, Japan, China and South Korea, on possibilities for cooperation on R&D and operational missions providing GACS relevant observations: In particular with JAXA and NIES in Japan for their GOSAT and potential follow-on mission on GHG measurements. 4.4 Research and development European research and demonstration missions Atmospheric chemistry missions in the ESA Earth Explorer programme Three out of six ESA currently proposed Earth Explorer Mission Concepts (TRAQ, PREMIER, and ASCOPE) have potentially relevance for GACS. Selection criteria for Earth Explorer missions, as defined by ESA, are strongly weighted towards scientific research objectives. If one of the three relevant candidate Explorer missions is selected for implementation, it can potentially offer a contribution to monitoring as well, and possibly serve a pre-operational function. Conversely, integration of these data in GACS would be a natural part in the evaluation of its possible operational value. It is recommended that, should any of these three missions identified above be selected, its potential to temporarily augment the operational satellite system (comprising EPS-MetOp, MSG and NPP/NPOESS) in support of GACS be assessed, in consistency with the GMES Sentinel programme Other European national initiatives for atmospheric chemistry A number of initiatives exist on national, bilateral or multilateral basis to support important research proposals also with the intention to demonstrate precursors for operational missions (and to develop national scientific and technical competence). April 2009 Report of the GAS Implementation Group 42

43 Such European national initiatives are strongly endorsed where they bring a gap-filling (Sentinel-5 precursor) contribution, and/or are addressing requirements that cannot be met by the ESA Sentinels European research missions for aerosol-cloud-radiation interactions Several existing (CALIPSO and PARASOL as part of the A-Train: see above) and future (EarthCARE through European-Japanese cooperation) missions address the understanding of the aerosol-cloudradiation interactions that play a role in climate regulation. Inasmuch as these missions aim at improving the representation and understanding of the Earth's radiative balance in climate and numerical weather forecast models by obtaining vertical profiles of clouds and aerosols, as well as the radiances at the top of the atmosphere, they are also fully relevant for GACS Measuring CO 2 from space As regards the GACS and the important challenge of measuring and monitoring CO 2 from space it is recommended: To maintain in any case R&D efforts and funding in order to progress toward operational measurements of atmospheric CO 2 concentrations. That an assessment should be made of in-orbit capabilities of the OCO & GOSAT research missions to: (a) Improve significantly on the quantification of CO 2 emission sources from assimilation of surface data and IRS (AIRS/IASI) radiances, and (b) enable GACS to comply with requirements for monitoring emissions on national and local scales which could otherwise not be met. Pending the outcome of such an assessment, it would then be timely to review observational requirements for an SWIR CO 2 sensor specification, and the feasibility of implementing as possible addition to Sentinel-5 (UVNS) or by other means (e.g. NASA or JAXA) Research and development activities on data exploitation It is recommended: To maintain R&D efforts and funding on methodologies and experiments dedicated to calibration and validation of data and products, on parameter retrieval from observations and on integration/assimilation of these data and products within numerical models, in close conjunction with GACS activities and development; Specifically, concerning additional IASI-derived trace GACS products, to enhance R&D efforts and related funding (from EC, ESA and EUMETSAT) in order to ensure that these products are transferred efficiently into the operational domain and exploited by GACS. April 2009 Report of the GAS Implementation Group 43

44 5. GACS functionality and architecture 5.1 Core service functional architecture and corresponding existing assets The proposed functional architecture of the GMES Atmosphere Core Service and its links with related activities is summarized in Figure 1. The Core Service is composed of these five generic elements which reside within the pale blue box. Figure 1: GAS functional architecture Observation acquisition and pre-processing This first generic element of the Core Service interfaces with the observation providers, namely: (i) the space agencies (EUMETSAT and its Satellite Application Facilities, ESA, and the other space agencies within and outside Europe); (ii) the operational and research in situ networks, including actors such as the existing projects based on commercial airplanes. In general, space agencies should be responsible for cal/val activities with regard to (singleinstrument) space observations. In situ networks should be responsible for the quality of their data. However, in the future coordination responsibility for GMES, the spelling out of quality parameters needed especially for GAS should be included, as these may differ from principal objectives of collecting networks. Cal/val activities in relation to CS products fall entirely within the GACS (within elements 5.1.2, and 5.1.4). April 2009 Report of the GAS Implementation Group 44