The spatial and temporal distributions of solar radiation and temperature were investigated to predict glacial meltwater discharge in the McMurdo Dry Valleys, Antarctica (77 30 deg.; 162 00 deg.). Average annual incoming solar radiation, as measured by pyranometer data, ranged from 84 to 117 W/m^2 during 1994 and 1995. Differences among stations were attributed primarily to terrain effects, but coastal cloudiness and orographic effects may also be factors. Average annual net solar radiation at soil-covered sites was 59 to 76 W/m.sq., while net solar radiation at glacier and lake-ice sites was lower, 18 to 52 W/m.sq. The difference was caused by the high albedo of snow and ice. Using a topographic solar radiation model, considerable topographic variability was found in solar radiation over the region, even averaged over a monthly time scale, with north facing slopes receiving more energy than south facing slopes. In the valley bottom, differences in incident radiation were discerned among lakes. Lake Fryxell received a uniform amount of energy while Lakes Hoare and Bonney received less energy along their northern shores due to terrain shading. Hourly radiation maps and pyranometer data illustrated that the cliff faces of the glaciers received more intense solar radiation than their surfaces, but this intense illumination was of short duration, occurring only when the sun directly strikes the cliff faces.

Satellite-derived data were used to investigate the distributions of radiative fluxes and snow-covered area in the dry valleys. Pixel values of temperature, albedo, and shortwave radiation from NOAA AVHRR images compared favorably to field data, although a finer temporal resolution of satellite data would be needed to fully capture the temporal trends. Images of snow-covered area correctly identified areas of little or no fractional snow in most cases, but further modifications of the spectral mixture analysis used will be necessary to distinguish shaded snow from ice covered surfaces.

The NOAA AVHRR temperature maps were used to calculate indices for predicting streamflow in Taylor Valley. While seasonal discharge was not well predicted by the indices, diurnal discharge was well characterized by a linear relation between streamflow and a source-area temperature distribution with a threshold at 259 deg K. This satellite-derived index, called the temperature area index, has great potential for streamflow and climate change studies in both Taylor Valley and other remote areas in the McMurdo Dry Valleys of Antarctica.