Solar Radiation Processes on the East Antarctic Plateau

University Of Washington, Seattle WA

Investigators

Abstract

0003826 Warren This project is an experimental study of solar radiation processes near the surface at Dome C, the French-Italian station in East Antarctica. It will be carried out in cooperation with the Labortatoire de Glaciologie et Geophysique de l'Environment in Grenoble, France. The emphasis will be on the reflection of sunlight by snow, and the transmission of sunlight through clouds. The observations will have relevance to climate, remote sensing, and the physics of ice and snow. Both spectral (narrow-band) and broadhead transmissions of solar radiation through clouds will be measured, and these measurements will be used to obtain effective cloud optical depths for use in estimating cloud radiative forcing with applications in climate models. A method to obtain this information from pyranometers alone will be developed so that the historical record of solar radiation observations in the antarctic interior can be analyzed for climatological information on clouds. Observations of the angular pattern of solar radiation reflected from the snow surface will allow the validation of satellite-derived atmospheric profile information. The measured surface reflection functions will be reconciled with the empirical functions obtained from Advanced Vidicon High Resolution Radiometers (AVHRR) on the NOAA series of polar orbiting satellites by radiative transfer modeling through the atmosphere. Finally, the spectral peak of snow albedo will be accurately located in order to resolve a discrepancy concerning the spectral absorption of pure ice in the visible to near-ultraviolet range.