HR: 0800h
AN: A21B-0439    [Abstracts]
TI: Integrating retrieved cloud information with model simulation to extend usability of tracer gas retrievals.
AU: Tan, Q
EM: qtan@umbc.edu
AF: University of Maryland Baltimore County, 5523 Research Park Drive, Suite 320, Baltimore, MD 21228, United States
AU: * Prinn, R
EM: rprinn@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts avenue, Cambridge, MA 02139, United States
AB: We have explored the possibility of using retrieved cloud information to extend the usability of trace gas concentration retrievals from satellites, since choosing only cloud-free retrievals might lead to a bias in their source-sink estimates using inverse modeling, i.e. the geographic locations of cloud-free or cloudy regions and trace gas source or sink regions might be correlated. We used methane retrievals (IMAP) and cloud retrievals (FRESCO) from SCIAMACHY as an example for this study, and assumed agreement between 3D model simulations (MATCH) and cloud-free satellite retrievals as a proxy for defining usability of satellite data. We found that when the pixel is very cloudy (f>0.7), the model simulation, which is integrated with retrieved cloud top height and cloud fraction data, yields similar agreement with observations as obtained with cloud-free pixels (f=0). The addition of cloudy pixel data significantly extends the spatial and temporal coverage of methane retrievals that can be used in source and sink studies. We also tried to overlay the MODIS aerosol retrievals with SCIAMACHY methane data to test the impact of aerosols on trace gas retrievals. Since these two retrievals are somewhat orthogonal, i.e. stronger MODIS aerosol signals over the ocean, and stronger SCIAMACHY methane signals over the land, we have not found a significant correlation between these two retrievals. Other possible reasons for this result could be the different passing times of the two satellites and the wave length differences of the two retrievals.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0319 Cloud optics
DE: 0480 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting