Eyjafjallajökull volcano ash plume operational monitoring all over Europe th ground based and airborne mounted lidars

Transcription

1 Eyjafjallajökull volcano ash plume operational monitoring all over Europe th ground based and airborne mounted lidars S.Lolli 1,M. Barbec 2, A. Cirisan 2, I.m Engel 2, F. G. Wienhold 2, J. P Cariou 1, L. Sauvage 1, L. Thobois 1 1 LEOSPHERE, Rue Rostand, 91400, Orsay, France 2 ETH, Universitaetstrasse 16, 8092 Zurich, Switzerland.

2 MODIS image at 11:39 (UT) the 15 th April 2010 Eruption of the Eyjafjallajökull volcano in Iceland Explosive phase of the eruption starts: 2010/04/14 at 3am (UTC) Volcanic ash

3 perational strategy and available tools for volcanic ashes survey Operational period (from 14 th April to 27 th May 2010) ear-real Time orecasts from AROME model (Météo-France) operational ground-based UV polarized elastic Backscattering Lidars eosphere) alcon 20 and ATR-42 from SAFIRE team (Météo-France, CNRS, CNES) irborne lidar (CEA) utomatic daily quicklooks of range corrected backscattered power loaded to VAAC (Volcanic Ash Advisory Center) coordinated by UK Met fice and to Meteo France Post-treatment and data analysis ssessing mass concentrations odeling of the dynamic of the volcanic plume at the synoptic scale olyphemus/polair3d) and comparison with lidar observations

4 chnical sheet ALS 300/450 lidars

5 Leonet( Ground-based Operational Tool LEOSPHERE has developed since 2009 a website to plug online the S elastic lidars with the following objectives: To provide an internal follow up To stock and backup measurement data on a central server To check the status of the instruments during the field campaigns EGAPOLI Paris, Air quality for Commonwealth games in Delhi..) To provide a potential support to existing research lidar networks Since 16 th of April 2010 turned into an operational tool to mediate support the decision makers during the Volcano crisis oviding range corrected backscattered power quicklooks of parallel d perpendicular channels on hourly basis.

6 twork with 9 (potentially 14) operative stations in Europe providing: ages of the attenuated backscatter (//, channels) resolution: 15m 100m -20 km solution 30s

7 Ground-based measurements: results Ash plume observed from N 2 -Raman lidar at CEA Saclay site AOD 355 = 0.08±0.05 risk threshold for engines: 2 mg/m 3 vigilance threshold: 200 µg/m 3 Volcanic ash Planetary boundary layer

8 Ground-based measurements: results Ash plume observed with EZ Lidar at Orsay site

9 Airborne measurements : instrumentation ALS Lidar onboarded in the Falcon 20 in order to monitor the volcanic plume Falcon 20 SAFIRE Acquisition system Optical head of the lidar pointing at the nadir in the Falcon 20

10 Airborne measurements : results (1) irst operational flight with the lidar onboard the Falcon 20 Altitude (m) Apparent backscattering coefficient (10 3 km 1.sr 1 ) 21 st April 2010 Volcanic ash Boulognesur Mer Strasbourg Caen Amboise Toulouse

11 Airborne measurements : results (2) British air space closed Attenuated backscattering coefficient (10 3 km 1.sr 1 ) 16 th May 2010 Volcanic ash AOD=0.5 Clouds

12 m Lidar signal to mass concentration: preliminary results at ETHZ

13 ETHZ: COBALD RS and ASL Lidar. 55sr Balloon sounding: 17 th April (UTC) ALS Lidar : 17 th April (UTC) Data supports a LR of 55-60sr

14 ore challenging: from optical signal to mass concentration ETHZ

15 ore challenging: from optical signal to mass concentration ETHZ nhanced signal at about 5km in the balloon profile characterizes a distinct l layer, which in conjunction with the relative humidity of 30%, the neous Lidar measurements and the trajectory analysis is identified as the ic ash above zurich

16 ore challenging: from optical signal to mass concentration ETHZ computations were performed to fit parameters of a bimodal size tribution (sulfate and ash mode) to the observed backscatter values of tinuously running aerosol and cloud lidar and in situ by balloon borne 1.4 at nm and 17.5 at 870 nm (COBALD) and the extinction of measurements ve Zurich, Switzerland, km-1 at 355 nm (lidar). The table provides overview of the fit parameters. Fit results yielding in a root mean squared iation to the observed values of less than 1% were considered in a

17 Example of fit of the bimodal size distribution esponding on observed backscattering values of 1.4 at 455nm, 17.5 at 855nm 25 km-1 extinction coefficient measured by lidar at 355nm. art equi distributed, imaginary part peak between and 0.004

18 ore challenging: from optical signal to mass concentration ETHZ

19 ore challenging: from optical signal to mass concentration ETHZ 150 µg/m3 600µg/m3 risk threshold for engines: 2000µg/m 3 vigilance threshold: 200µg/m 3

20 More challenging: from optical signal to mass concentration espite the large number of degrees of freedom most of the fit results over in total) constrained by the optical measurements yield a ass density between 80 and 150 µg/m 3 and a conversion factor in the ange of 0.65 to 1 g/m 2 ower values as compared to those used in the literature for mass lume estimates, which is explained by the fact that the effect of the ulphate mode only marginal in mass, but significantly contributing o the 355 nm extinction is not attributed in the values adopted from rdinary mineral dust he noontime extinction peak on 17 April, four times higher than uring the sounding, is consequently associated with a maximum ass density of 600 µg/m3.

21 Conclusion and perspectives Lack of existence of magic numbers that can convert extinction profiles into mass concentration. Mass estimation is retrieved with big efforts using synergy between different remote sensors Leonet network was an immediate operational tool in support of decision makers providing spatio-temporal evolution of the ash layer over Europe In the future, simple one wavelength new ALS lidars (Raman N2, with depolarization ) can integrate lidar super sites with research proposals as operational tool for ash dust events surveillance and trans-boundary pollution studies.

22 Thank you