Wednesday, 12 January 2005
Parameterizing snow albedo by means of ARM data measured at Barrow, Ak
All state-of-the-art land surface models use parameterizations of various complexity to describe snow albedo. Some parameterizations include various environmental information like wind speed and air or snow temperature, while others use snow related characteristics like snow grain-size, snow depth, snow density or snow age. Combinations of environmental and snow characteristics also exist. We derived snow albedo from the ratio of out-going to incoming solar radition using three years of ARM data obtained at Barrow, Alaska. The first two years of the albedo dataset served to develop a new parameterization of snow albedo, while the third year's data were used to evaluate the new snow-albedo parameterization. The new parameterization of snow albedo will be presented. It considers snow-age, snow depth, wind speed, and air temperature. Snow albedo calculated with this new parameterization was compared to other snow-albedo parameterizations given in the literature. Evaluation of the improvement of the new parameterization will be demonstrated by use of the data from the third year, as this year's data have not been used for the development of our snow-albedo parameterization.