1. Methane inversion from satellite, TRANSCOM workshop, Jena, 12-15 May 2003 Inverse modelling of methane sources and sinks using satellite observations Jan Fokke Meirink, Henk Eskes, Michiel van Weele, Albert Goede Royal Netherlands Meteorological Institute (KNMI)

2. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Overview EVERGREEN SCIAMACHY inverse modelling strategy first experiments

3. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 EVERGREEN EnVisat for Environmental Regulation of GREENhouse gases EC 5 th framework programme Feb. 2003 – Feb. 2006 Objective: use ENVISAT (SCIAMACHY and MIPAS) measurements for inverse modelling of GHG emissions Partners: KNMI (NL, coordinator), Univ. Bremen (DE), Univ. Leicester (GB), Univ. Heidelberg (DE), NILU (NO), SRON (NL), MPI-BGC (DE), BIRA-IASB (BE), UPMC-SA (FR), RWE-Rheinbraun (DE), Univ. Liège (BE), EC-JRC-IES (IT) website: http://www.knmi.nl/evergreen

4. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 EVERGREEN: tasks Retrieval and validation: CH4, CO, (CO2), O2 columns; clouds Radiation budget modelling: use of measured trace gas distributions in radiative forcing calculations (Inverse) modelling: CH4, CO, CO2 emission inventory (forward) model intercomparison ( 222 Rn, SF 6,...) inverse modelling

5. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 SCIAMACHY on ENVISAT CH4 CO CO2

6. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 SCIAMACHY measurements No useful retrievals yet: calibration problems (mainly dark current correction) ice layers on the detectors, channel 7 and 8 NIR retrieval quality will depend on: albedo: over water low signal-to-noise ratio solar zenith angle clouds

7. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 SCIAMACHY: example nadir measurements (simulated)

8. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Chemistry-transport model TM3 horizontal resolution: 7.5x10 / 3.75x5 / 2.5x2.5 deg vertical resolution: 19 / 31 layers up to 10 hPa slopes scheme for advection ECMWF meteorology 37 tracers (22 transported) CBM-4 scheme for NMHC chemistry nudging at model top to climatology (O3) and UARS data (CH4) single-tracer version with OH fields from full model

9. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Planned model setup in Evergreen horizontal resolution: 2x3 deg extension of model in vertical direction: use subset of ECMWF layers up to 0.1 hPa nudging of CH4 to surface observations to have model reproduce measured NH-SH gradient up-to-date emissions from WP 4100

10. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Inversion strategy 4D-var method adjoint model of TM3 CH4-only version has been developed optimize surface fluxes and initial CH4 field expected: in the beginning adjustments to CH4 field, later to surface fluxes time frame: 1 week to 1 month

11. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 4D var (1)

12. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 cost function 4D var (2) state vector x = [c,f] background error covariance observation error covariance observatio n observatio n operator model

13. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 4D var (3) gradient of the cost function adjoint model

14. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Preconditioning S diagonal matrix with standard deviations LL T symmetric matrix with correlations

15. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 First experiments First week of January 2000 Sat.obs. taken from perturbed model run Optimize emissions only Background error covariance Standard deviation: 50% of emission Horizontal correlation function: Gaussian with length scale of 1000 km Observation error covariance Diagonal; standard deviation: 0.5% of column

16. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 A priori emissions

17. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Perturbed run 50% enhanced emissions

18. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Effect on CH4 field after one week

19. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Pseudo satellite observations

20. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Optimized CH4 emissions

21. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Resulting CH4 field

22. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Setting  obs to 2%

23. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Adding 0.5% noise to sat.data

24. Methane inversion from satellite, TRANSCOM meeting, Jena,12-15 May 2003 Summary EU project EVERGREEN for emission estimates of CH4, CO, and possibly CO2, using satellite data. SCIAMACHY has the potential of measuring CH4 and CO columns, but first some calibration problems have to be solved. Inverse modelling of CH4 using 4D-var has been set up at KNMI and first experiments have been done.