Energy Balance

Alterations of the global radiation budget exert the most direct influence on global climate. In addition to the solar elevation angle and the duration of sunlight, the radiation budget is controlled by atmospheric scattering and absorption, clouds and haze, atmospheric (trace gas) chemistry, and the surface albedo. These factors are intricately linked with each other through various feedback loops and represent major uncertainties in an assessment of the Arctic's role in global climate (AMAP, 1998). Fluxes of latent, sensible, and conductive heat are largely controlled by the physical processes at the surface, including melting, evaporation, precipitation, and air-sea-ice interactions. Changes in sea ice characteristics (extent, thickness, snow cover) particularly affect the energy exchange between ocean and atmosphere and the surface albedo (see below). The cloud cover and the extent of sea ice, ice caps, and snow cover strongly influence the regional to global radiation budget through their effects on the planetary albedo and large-scale albedo gradients. The latter influence global atmospheric circulation patterns.

0 0

Post a comment