11th Conference on Atmospheric Radiation and the 11th Conference on Cloud Physics

Wednesday, 5 June 2002: 10:30 AM
Observed and modeled atmospheric absorption in ARESE II
Shelly K. Pope, SIO/Univ. Of California, La Jolla, CA; and F. P. J. Valero, B. C. Bush, Q. T. Nguyen, and D. C. Marsden
Observations of the absorption of solar radiation by the atmosphere in ARESE II are compared to calculations performed with several different radiative transfer models. It is found that the calculated absorption differs from the observed value by a significant amount in cloudy conditions, with models underpredicting the absorption. It is also found that the models, all using identical input, differ among themselves significantly, e.g. yielding absorptance estimates ranging from 15% to 19% for the column of atmosphere from the surface up to 7 km. Model values of clear sky absorptance are in agreement with the observations within experimental uncertainties. These results are from ARESE II; a comparison with ARESE I results shows agreement within observational uncertainties. As in ARESE I, visible absorptance is present on some days at levels of up to 2.5%, which can be attributed to the presence of aerosols.

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