Examples of Enhanced Global Solar Radiation Through Multiple Reflection from an Ice-Covered Arctic Sea

Abstract

Three years of simultaneous measurements of incoming and reflected solar radiation for adjacent snow-free land and ice-covered sea surfaces along the Hudson Bay coastline indicate that multiple reflection enhancement can be large over high-albedo surfaces in the presence of cloud. The type and thickness of cloud is the major factor determining the magnitude of multiple reflection, and there is a wide range in cloud base albedos. When, under cloudy skies, the global solar radiation equals the magnitude for clear skies, it is due to the fact that the clouds are thin and largely transparent to the solar beam, rather than to multiple reflection enhancement.