An investigation of terrain irradiance in a mountain-glacier basin

A remotely sensed method of assessing radiative-transfer processes which considers distinctive zones in the mountain-glacier drainage basin, increases the potential for comprehensive radiative-exchange analysis. By investigating terrain-reflected and terrain-emitted radiation using Landsat-5 Thematic Mapper images and digital elevation data, the objective of this study is to demonstrate the importance of local exchange in the computation of net shortwave and longwave radiation. The results show that terrain-reflected radiation estimates are required to calculate the total shortwave spectral irradiance in all parts of the basin This is necessary to compute accurate surface-cover reflectance and albedo values from the satellite imagery. Furthermore, the assessment of the terrain-emitted radiation explains why, especially on a clear day, the snow and ice covers in many parts of the basin have a very small longwave radiation deficit.