HR: 16:35h
AN: GC34A-03    [Abstracts]
TI: Spectrally resolved infrared radiances from AIRS observation and GCM simulation
AU: * Huang, Y
EM: Yi.Huang@noaa.gov
AF: Princeton University, 201 Forrestal Road, Princeton, NJ 08540,
AU: Ramaswamy, V
EM: V.Ramaswamy@noaa.gov
AF: NOAA/GFDL, 201 Forreatal Road, Princeton, NJ 08540,
AB: Global multi-year spectrally resolved infrared radiances observed by the Atmospheric Infrared Sound (AIRS) satellite instrument and simulated from the General Circulation Models (GCMs) of the Geophysical Fluid Dynamics Lab (GFDL) are processed to obtain long-term global and regional means as well as the associated spatial and temporal variability. The accumulated radiance data comprise a host of phenomena that are still largely unrecognized but reveal important physical processes. For instance, the correlation between the radiances and the Sea Surface Temperatures (SSTs) discloses the roles of water vapor in both upper (via its v2 band) and lower (via the continuum in the window region) troposphere, and that of clouds regarding the so called "super greenhouse effect" in Tropics. A comparison between observed and simulated radiances demonstrates that radiance affords a stricter and more insightful metric than the broadband flux. A seemingly good agreement of OLR flux may arise from cancellation of errors of opposite signs in different spectral regions; radiance biases are indicative of physical causes because the radiances at each frequency are sensitive to factor(s) at different levels. Model validation at the radiance level thus provides a complementary and integrative perspective to that obtained using meteorological variables. It is demonstrated that the radiance discrepancies between the GFDL model and the observation are consistent with the model biases in temperature, water vapor and clouds.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3337 Global climate models (1626, 4928)
DE: 3359 Radiative processes
DE: 3360 Remote sensing
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting