A comparison of surface renewal theory with the observed roughness length for temperature on a melting glacier surface

Abstract

The roughness lengths for momentum and temperature are calculated using the profile method on amelting glacier surface. Data from a 5-level 9-m meteorological mastpositioned near the edge of Breidamerkurjokull, an outlet glacier of the Vatnajokull ice cap Iceland, are used for the calculations. The data are selected to avoid the presence of the katabatic wind speedmaximum which would otherwise alter the scaling laws of the surface layer. The surface roughness length for momentum is determined to be 1.0 mm, similar to other estimates made on flat melting ice surfaces. The surface roughness length for temperature is found to be in good agreement with previously proposed surface renewal theories for the observed roughness Reynolds number range of 30 * 70.