How accurate the satellite observations need to be? --required accuracy of satellite data to provide information beyond ground based observations for optimization of the CH4 flux estimate

HR: 0800h
AN: A41C-0050 [Abstracts]
TI: How accurate the satellite observations need to be? --required accuracy of satellite data to provide information beyond ground based observations for optimization of the CH4 flux estimate
AU: * Tan, Q
EM: qiantan@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 United States
AU: Prinn, R G
EM: rprinn@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 United States
AU: Buchwitz, M
EM: Michael.Buchwitz@iup.physik.uni-bremen.de
AF: University of Bremen, Otto-Hahn-Allee 1 PO Box 33 04 40, Bremen, D-28334 Germany
AU: Ortega, J M
EM: jmoa@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 United States
AU: de Beek, R
EM: debeek@iup.physik.uni-bremen.de
AF: University of Bremen, Otto-Hahn-Allee 1 PO Box 33 04 40, Bremen, D-28334 Germany
AU: Burrows, J
EM: burrows@iup.physik.uni-bremen.de
AF: University of Bremen, Otto-Hahn-Allee 1 PO Box 33 04 40, Bremen, D-28334 Germany
AB: We examine the strengths and weaknesses of various types of atmospheric methane (CH₄) observations through a synthetic inverse modeling study. The NCAR Model of Atmospheric Transport and Chemistry (MATCH) is used to generate synthetic CH₄ measurements at existing ground-based CH₄ observation sites and along a sun-synchronized satellite orbit. The ground sites chosen are based on the WDCGG, which reports multi-network CH₄ surface mixing ratio measurements, and the NDSC, which observes column burdens of CH₄. The parameters of the SCIAMACHY onboard ESA's EnviSat satellite are used to specify the satellite orbit within the MATCH model. Methane surface emission estimates used here to drive MATCH to produce the synthetic measurements are from the Chen and Prinn (J. Geophys. Res., 2005a,b) inverse modelling study that using the actual real-time CH₄ surface measurements. The assumed uncertainty of ground-based synthetic MATCH concentrations is also based on the real observations. Through Kalman filter inversion, we estimate the threshold uncertainty of satellite observations, above which the uncertainty in CH₄ emission estimates using satellite data exceeds those using surface data alone. We also report the results of a comparison of the model simulations with real time surface measurements, as well as with SCIAMACHY CH₄ data (WFM-DOAS version 0.5, Buchwitz, et al., Geophys. Res. Letts., 2005) for the year 2003.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0312 Air/sea constituent fluxes (3339, 4504)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005