The role of radiation geometry in the climate response of mount kenya's glaciers, part 2: Sloping versus horizontal surfaces

This part of the study expands the modelling of incident solar radiation on Mount Kenya and its glaciers to include the behaviour for sloping as compared to horizontal surfaces. It is concluded that for the purposes of the ongoing climate study the broad‐scale generalizations reached in part 1 of the study for horizontal reference surfaces remain inviolate for sloping reference surfaces. However, significant additional information is brought out by reference to sloping surfaces. Further, differences in absolute radiation magnitudes are significant for realistic situations of cloudiness and shading when modelling short‐term (e.g. monthly) radiation means. In the annual case, these differences are small for glaciers having mean gradients up to 45°; for the one extremely steep glacier with mean slope approaching 60°, these differences are significant. It is anticipated that for higher latitudes the discrepancies between sloping and horizontal reference surfaces in the annual case may well be more substantial. For Mount Kenya, located as it is almost directly under the Equator, it must be concluded that the conventional horizontal reference surface is indeed appropriate for climatic heat and mass budget analyses.