Accessing Global Precipitation Data Products via TRMM Online Visualization and Analysis System (TOVAS) Zhong Liu Center for Spatial Information Science and Systems (CSISS), George Mason University and NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)
Outline Brief overview of TRMM Introduction of TOVAS Precipitation products in TOVAS TOVAS interface overview Functions and examples Other ancillary tools Future plans Other TRMM data and services at GES DISC Demos and hands-on exercises Questions
Brief Overview of TRMM Tropical Rainfall Measuring Mission (TRMM) Sampling footprint between 35 S and d35 N 4-D distribution of rainfall and latent heating over vastly under-sampled oceanic and tropical continental regimes
PR 247Km (5km) TMI 878km (5.1km, 85.5GHz) VIRS 833 km (2.4km) GES DISC is the TRMM data archive center Courtesy of trmm.gsfc.nasa.gov
TOVAS Introduction ti Why TOVAS?
Traditional Way vs. TOVAS in Data Evaluation for a New User Traditional Way: Obtain data from a FTP site Read data manuals Learn software if available If not available, write your own software Write visualization software TOVAS: Basic analysis and visualization (no software and data download needed)
TOVAS
Reliable Flexible Low-cost System Description Visualization and Analysis Server Receive Parameters from Interface CGI Receive Parameters from Web Client Compose GrADS Script GrADS Environment Execute Generate GrADS Plot/ASCII Script Output Output to Web Browser Output to Web Client Data: Binary or GDS GrADS: The Grid Analysis and Display System (COLA)
Products in TOVAS Near-real-timereal Rainfall Archives Ground Observation Archives Other Ancillary Products
Near-real-time 3-Hourly combined (3B42RT) 3-Hourly microwave (3B40RT) Hourly IR (3B41RT) Daily (derived from 3B42RT)
Rainfall Archives 3-Hourly y( (3B42) Daily y( (derived from 3B42) 10-day y( (derived from 3B42) Monthly (3B43, 3A12, 3A25, GPCP, etc.)
Ground Observation Archives Willmott (1950-1999, 0.5 deg) GPCC (1986 present, 1 deg)
Others: Monthly Global Precipitation (GPCP) Prototype Interactive Inter-comparison of Rainfall Products Monthly Rainfall (3B43 V6) Anomaly Inter-Comparison of Rainfall Climatology
TRMM Web Interface Overview
TOVAS Landing Page: http://disc2.nascom.nasa.gov/giovanni/tovas/ /Gi i/t / New
Two types of GUIs
Accessing new interfaces: New
TOVAS Functions and Examples
TOVAS Functions: Animation Lat-Lon Area Plot, Time-averaged Lat-Lon Lon Plot, Difference Map Latitude-Time Hovmöller Plot Longitude-Time Hovmöller Plot Correlation Plot Comparison Plot Cross-Map Plot (Latitude-Height) Cross-Map Plot (Longitude-Height) Cross-Map Plot (Time-Height) Scatter Plot Scatter Plot, Time-averaged Time Series, Area-averaged Time Series Difference Time Series, Area Statistics
Other Features: Climatology l Anomaly and normalized anomaly Fine tune graphic output Output in other formats (e.g., NetCDF) Google Earth hkmzfil file output Application examples with real events FAQ and documentation Help desk
2D Lat-Lon Plots (Record breaking rainfall in the Mid- Atlantic Region in 2003) Atlantic Region in 2003)
2D Plots (The contribution of Isabel in 2003) Isabel
Time Series Plots Floyd Alex, Charley, Gaston Isabel Mid- Atlantic Region
Hovmoller Diagram (Mid-Atlantic Region) Multiple Tropical Storms Isabel Floyd
Anomaly (Positive anomaly due to Isabel in Sept., 2003)
Scatter Plot (Error vs Rain Rate, revealing biases)
ASCII data output for further analysis (e.g. MS. Excel)
Prototype Interactive Inter-comparison of Rainfall Products
Other Ancillary Tools Hurricane Data Analysis Tool (HDAT) Other Giovanni Tools
Hurricane Data Analysis Tool: http://disc.gsfc.nasa.gov/hdat /HDAT The global merged IR product, also known as, the NCEP/CPC 4km Global (60ºN - 60ºS) IR Dataset, is one of TRMM ancillary datasets. 4 km IR Global (60ºN - 60ºS) 30 minutes Since Feb., 2000
Basic Functions and Features: Selection of area of interest Single image or multiple l images (animation) Allow time skipping (1 hr., 2 hr., etc.) Allow different image sizes False color Fine tune graphic output
HDAT Landing Page
HDAT Landing Page (Cont.):
HDAT Landing Page (Cont.):
HDAT Landing Page (Cont.):
Examples: Category 2 cyclone Catarina Landfall
AF Flight-447: Satellite Observation of Mesoscale Convective g System Development on 1 June, 2009
Dust Strom (near Iraq and Saudi Arabia border)
Dust Storm (cont.)
TOVAS and HDAT 2009 2010 Flooding in Pakistan due to higher-than-normal monsoon rainfall between Jul Aug. 2010
Other Giovanni Tools: http://disc.sci.gsfc.nasa.gov/giovanni i / i i Giovanni: GES-DISC (Goddard Earth Sciences Data and Information Services Center) Interactive Online Visualization ANd analysis Infrastructure
Cloud Water in g/m3 Cloud Ice in Precipitation Ice (scaled by 100) g/m3 (scaled in g/m3 3( (scaled by 100) by 100)
Future Plans for TOVAS: Add more functions IPWG: a proposal p for adding IPWG validation algorithms is pending Add TRMM Level-2 orbital ldata (a prototype to extract 2A12 and 2A25 profiles is ready for YOTC) Add multi-sensor data (e.g., CloudSat)
Other TRMM data and services at GES DISC Mirador Other data accessing methods
TRMM Data Archive at GES DISC
Data Volumes (as of Sept. 22, 2010) Standard products (L-1, L-2, L-3, orbital, gridded): ~20.3 TB (772,553 files) Ancillary data: ~1.9 TB (93,051 files) Ground based instruments: ~4.5 TB (1,853,484) Subsets: ~3.1 TB (2,995,019) File Total: 5,714,107 Total size: ~29.7 TB
Mirador Basic Features: http://mirador.gsfc.nasa.gov/ Search features: Keyword/event search, projects, science focus areas Spatial subsetting (limited products) Format conversion (e.g., NetCDF)
Other Data Access Methods: Giovanni TOVAS (TRMM Online Visualization and Analysis System) GrADS Data Server (GDS) (subsetting and analysis services over the Internet) OPeNDAP (accessed by IDL, GrADS) The Open Geospatial Consortium (OGC) Web Map Server (WMS) Google Earth
Demos and Hands-on Exercises
Generate a lat-lon map Generate a time series and its ASCII data New interface and data download options
URLs: TOVAS: http://disc2.nascom.nasa.gov/giovanni/tovas/ nasa HDAT: http://disc.sci.gsfc.nasa.gov/hdat Mirador: http://mirador.gsfc.nasa.gov/ Giovanni: http://disc.sci.gsfc.nasa.gov/giovannisci gov/giovanni GES DISC: http://disc.sci.gsfc.nasa.gov/ Contact: Zhong.Liu@nasa.gov
Thank You!