TY - JOUR
T1 - An intercomparison of radiation codes for retrieving upper-tropospheric humidity in the 6.3-μm band
T2 - A report from the first GVaP workshop
AU - Soden, Brian
AU - Tjemkes, S.
AU - Schmetz, J.
AU - Saunders, R.
AU - Bates, J.
AU - Ellingson, B.
AU - Engelen, R.
AU - Garand, L.
AU - Jackson, D.
AU - Jedlovec, G.
AU - Kleespies, T.
AU - Randel, D.
AU - Rayer, P.
AU - Salathe, E.
AU - Schwarzkopf, D.
AU - Scott, N.
AU - Sohn, B.
AU - De Souza-Machado, S.
AU - Strow, L.
AU - Tobin, D.
AU - Turner, D.
AU - Van Delst, P.
AU - Wehr, T.
N1 - Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2000/4
Y1 - 2000/4
N2 - An intercomparison of radiation codes used in retrieving upper-tropospheric humidity (UTH) from observations in the v2 (6.3 μm) water vapor absorption band was performed. This intercomparison is one part of a coordinated effort within the Global Energy and Water Cycle Experiment Water Vapor Project to assess our ability to monitor the distribution and variations of upper-tropospheric moisture from spaceborne sensors. A total of 23 different codes, ranging from detailed line-by-line (LBL) models, to coarser-resolution narrowband (NB) models, to highly parameterized single-band (SB) models participated in the study. Forward calculations were performed using a carefully selected set of temperature and moisture profiles chosen to be representative of a wide range of atmospheric conditions. The LBL model calculations exhibited the greatest consistency with each other, typically agreeing to within 0.5 K in terms of the equivalent blackbody brightness temperature (Tb). The majority of NB and SB models agreed to within ±1 K of the LBL models, although a few older models exhibited systematic Tb biases in excess of 2 K. A discussion of the discrepancies between various models, their association with differences in model physics (e.g., continuum absorption), and their implications for UTH retrieval and radiance assimilation is presented.
AB - An intercomparison of radiation codes used in retrieving upper-tropospheric humidity (UTH) from observations in the v2 (6.3 μm) water vapor absorption band was performed. This intercomparison is one part of a coordinated effort within the Global Energy and Water Cycle Experiment Water Vapor Project to assess our ability to monitor the distribution and variations of upper-tropospheric moisture from spaceborne sensors. A total of 23 different codes, ranging from detailed line-by-line (LBL) models, to coarser-resolution narrowband (NB) models, to highly parameterized single-band (SB) models participated in the study. Forward calculations were performed using a carefully selected set of temperature and moisture profiles chosen to be representative of a wide range of atmospheric conditions. The LBL model calculations exhibited the greatest consistency with each other, typically agreeing to within 0.5 K in terms of the equivalent blackbody brightness temperature (Tb). The majority of NB and SB models agreed to within ±1 K of the LBL models, although a few older models exhibited systematic Tb biases in excess of 2 K. A discussion of the discrepancies between various models, their association with differences in model physics (e.g., continuum absorption), and their implications for UTH retrieval and radiance assimilation is presented.
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U2 - 10.1175/1520-0477(2000)081<0797:AIORCF>2.3.CO;2
DO - 10.1175/1520-0477(2000)081<0797:AIORCF>2.3.CO;2
M3 - Article
AN - SCOPUS:0001458461
VL - 81
SP - 797
EP - 808
JO - Bulletin of the American Meteorological Society
JF - Bulletin of the American Meteorological Society
SN - 0003-0007
IS - 4
ER -