Downwelling longwave fluxes at continental surfaces - A comparison of observations with GCM simulation and implication for the global land-surface radiation budget

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Journal of Climate

DOI:https://doi.org/10.1175/1520-0442(1996)009<0646:DLFACS>2.0.CO;2· OSTI ID:273952

Garratt, J R; Prata, A J ^[1]

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1. CSIRO Division of Atmospheric Research, Aspendale, Victoria (Australia)

Previous work suggests that general circulation (global climate) models have excess net radiation at land surfaces, apparently due to overestimates in downwelling shortwave flux and underestimates in upwelling longwave flux. Part of this excess, however, may be compensated for by an underestimate in downwelling longwave flux. Longterm observations of the downwelling longwave component at several land stations in Europe, the United States, Australia, and Antarctica suggest that climate models (four are used, as in previous studies) underestimate this flux component on an annual basis by up to 10 W m{sup -2}, yet with low statistical significance. It is probable that the known underestimate in boundary-layer air temperature contributes to this, as would low model cloudiness and neglect of minor gases such as methane, nitrogen oxide, and the freons. The bias in downwelling longwave flux, together with those found earlier for downwelling shortwave and upwelling long-wave fluxes, are consistent with the model bias found previously for net radiation. All annually averaged fluxes and biases are deduced for global land as a whole. 21 refs., 2 figs., 3 tabs.

• OSTI ID: 273952
• Journal Information: Journal of Climate, Journal Name: Journal of Climate Journal Issue: 3 Vol. 9; ISSN 0894-8755; ISSN JLCLEL
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CLIMATE MODELS
CONTINENTAL CRUST
DATA COVARIANCES
GENERAL CIRCULATION MODELS
LONG WAVE RADIATION
RADIATION FLUX
SURFACE AIR