Analysis of the Temporal Variability of Positive Degree Day Factors

Sammanfattning: The surface mass balance determines the growth or decay of an ice sheet, by taking the difference between accumulation and ablation. In this thesis snow and ice ablation is related to 2m-temperature through the positive degree day method. The positive degree day method takes into account the ablation rate of snow and ice and the number of measurements with temperature above freezing level in order to compute the proportionality constant between the two. Positive degree day factors for snow and ice are computed using data obtained from EC-Earth model simulations. The factors are computed for the present day climate and the Eemian in order to exploit their variability. The results demonstrate positive degree day factors to be visibly variating with the climate.