Monte Carlo modeling and measurements of actinic flux levels in Summit, Greenland snowpack

摘要

Knowledge of actinic flux levels in snowpack is needed to find the influence of snowpack photochemical processes on atmospheric composition. Measurements show that while < 0.2/100 of direct UV and visible light is transmitted through 0.7 cm of snowpack, downwelling actinic flux levels are at least 10/100 of incident levels at a depth of 10cm within the snowpack. This results from the highly forward-scattering nature of the snowgrains within the snowpack. A 1-D Monte Carlo model of photon scattering from, and absorption in, snowgrains accurately simulates relative actinic flux levels in a horizontally homogeneous, vertically layered representation of the upper meter of Summit, Greenland snowpack.