The Cold Surface Layer on Storglaciären

The thickness of the cold, water free surface layer was mapped using a high frequency radar. In the ablation area of Storglaciären the layer was approximately 30 m thick. It was thicker along the edges and thinner in the central part of the tongue. The thickness pattern shows similarities with the pattern of the vertical velocity on Storglaciären. Downgoing or slightly upgoing movement is associated with large depths of the cold surface layer and conversely, high rates of upgoing movement give shallow depts. The mapping was performed using a step-frequency radar (K-radar) which through Fourier analysis transformed changes in phase and amplitude of continuous wave (CW) signals into the time domain. The equipment was drawn on a sledge by a snow-mobile. The system is well prepared for field use and gives a good opportunity for data processing.