HR: 17:00h
AN: A34D-05    [Abstracts]
TI: Diagnosis of the Course Vertical Profile of Radiative Heating with CERES Surface and Atmosphere Radiation Budget (SARB) for Terra and Aqua
AU: * Charlock, T P
EM: ThomasP.Charlock@nasa.gov
AF: NASA Langley Research Center, Mail Stop 420, Hampton, VA 23681, United States
AU: Rose, F G
EM: Fred.G.Rose@nasa.gov
AF: Science Systems & Applications Inc, 1 Enterprise Pkwy Suite 2300, Hampton, VA 23666, United States
AU: Rutan, D A
EM: David.A.Rutan@nasa.gov
AF: Science Systems & Applications Inc, 1 Enterprise Pkwy Suite 2300, Hampton, VA 23666, United States
AB: The vertical profiles of SW and LW fluxes (surface, 500 hPa, 200 hPa, 70 hPa, and TOA) have been computed over the globe with the Langley Fu-Liou (FL) code and inputs for clouds from MODIS (Minnis et al.), aerosols from the MODIS-Atmosphere Team and the NCAR Model for Atmospheric Transport and Chemistry (MATCH), temperature and humidity from GEOS-4, and ozone from SMOBA (mostly SBUV). Surface spectral albedo for the ice-free ocean was based on Jin et al.; clear-sky broadband CERES SW observations and a look-up table to FL were used to develop surface albedo elsewhere. Tuned (i.e., based on adjustments to cloud properties) and untuned fluxes were compared with CERES at TOA for every footprint. Systematic validation with independent broadband SW and LW measurements at 60 sites worldwide has been a severe teacher on disparate accounts: RMS discrepancies of calculations with observations show that computed instantaneous diabatic profiles with clouds have limited meaning. For clear footprints over land, time-mean computed and observed surface insolations often agree, but this is partly due to offsetting errors in the code and aerosol inputs (MFRSR and Cimel photometers show MODIS Collection 4 land optical depths are too high). CERES broadband SW TOA observations appear to be low by 2-3 percent. Matched surface and TOA validation indicates, however, the LW profiles merit attention on the monthly scale: the interannual variability of surface LW downwelling compares astoundingly well with collocated ARM measurements of E13 and C01 (RMS of retrieval and measurement less than RMS of measurements). On both the interannual (deviation of an individual month from the calendar monthly mean) and synoptic (snapshot deviation from the mean of the individual month) scales, layer radiative heating correlates with layer water vapor more strongly than with layer temperature; and coherence in the upper troposphere exceeds that in the lower troposphere. Clouds introduce noise and reduce the correlation of layer radiative heating with water vapor, but all-sky regressions can have more slope than do clear-sky regressions, so total radiative divergence explained by fluctuations of water vapor increases in a cloudy sky. We will summarize such profile results from sites where matched TOA and surface validation give sufficient confidence.
UR: http://www-cave.larc.nasa.gov/ceres/
DE: 3311 Clouds and aerosols
DE: 3359 Radiative processes
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting