Simultaneous measurements of velocity and temperature in a turbulent boundary layer over melting ice*

As the effects of climate change become increasingly significant to the lives of people across the globe, the need for accurate modelling of rapidly melting glaciers is critical. Current models make use of a surface energy balance to quantify the contribution of several different heat fluxes to the overall glacier melt. Of these, the sensible heat flux (related to turbulent exchange of heat between the atmospheric boundary layer and glacier surface) is an important term, given its high variability and potential contribution to glacier melt. There is a demonstrated need for improved estimations of the sensible heat flux, as current methods to estimate it are either too impractical for widespread use, or use a series of assumptions that are invalid for typical glacier flows. In the present work, a series of controlled, laboratory, wind tunnel experiments were performed in which simultaneous measurements of two components of velocity and temperature were recorded in the turbulent boundary layer above melting ice. Statistics of velocity and temperature (including joint ones) were investigated over melting ice to better understand the nature of the turbulent boundary layer over a melting glacier, with the aim of improving glacier melt models.