Absorption of Solar Energy in the Atmosphere: Discrepancy Between Model and Observations

Abstract

An atmospheric general circulation model, which assimilates data from daily observations of temperature, humidity, wind, and sea-level air pressure, was compared with a set of observations that combines satellite and ground-based measurements of solar flux. The comparison reveals that the model underestimates by 25 to 30 watts per square meter the amount of solar energy absorbed by Earth's atmosphere. Contrary to some recent reports, clouds have little or no overall effect on atmospheric absorption, a consistent feature of both the observations and the model. Of several variables considered, water vapor appears to be the dominant influence on atmospheric absorption.

Absorption cross-sections of atmospheric constituents: NO2, O2, and H2O

“…OC10, BrO) in the stratosphere [3]. Furthermore, the absorption of atmospheric constituents is also required by the scientific community for the study of the transmission and radiative properties of the atmosphere where 02 and I420 play an important role [4,5]. Finally, some cloud properties can be deduced from the absorption bands of 02 and its collisioninduced spectrum [6,7].…”

Estimate of the Cloud and Aerosol Effects on the Surface Radiative Flux Based on the Measurements and the Transfer Model Calculations

“…There have been disputes over the discrepancy by 10-30 W m-2 between the observed, and the model calculated atmospheric absorptance (Cess et al, 1995;Ramanathan et al, 1995;Pilewskie and Valero, 1995;Wild et al, 1995;Arking, 1996;Stephens, 1996). These disputes are based on the estimates of the cloud radiative forcing at the top of the atmosphere and at the surface.…”

Decadal changes in shortwave irradiance at the surface in the period from 1960 to 2000 estimated from Global Energy Balance Archive Data

“…[2] Solar radiation intercepted by our planet will either be absorbed or returned to space by scattering and reflection [e.g., Arking, 1996;Wild et al, 1998]. The absorbed part of the solar radiation is the source of energy which drives the processes in the atmosphere and the oceans.…”