The Impact of Changing Ice Surfaces on the Glacier Boundary Layer Structure: A Large-eddy Simulation Case Study from Hintereisferner Glacier, Austria

The glacier boundary layer with katabatic down-slope wind strongly governs the exchange of heat between the ice surface and the atmosphere aloft. Glaciers are mostly located in mountainous regions, therefore mountain boundary layer processes (eg., other thermally-driven flows) and dynamically-driven processes such as gravity waves interact with the local glacier boundary layer, leading to disturbance or erosion of it.
In this study, we explore the impact of  dynamically-driven disturbances of the glacier boundary layer with large-eddy simulations. The location of the study is the Hintereisferner glacier in the Austrian Alps. We employ the WRF model at dx=48m to simulate the the evolution of the glacier boundary layer for one day during the HEFEX field campaign in 2018. The day is characterised by  mesoscale cross-glacier flow from the North-West. 
In a second simulation run, we remove the upstream glaciers to validate the impact of the ice surface on the formation of gravity waves. Generally speaking, removing the upstream glaciers leads to a modulation of the gravity waves and a changed sensible heat flux structure over the glacier, a weaker glacier boundary layer, and the propagation of an up-valley flow onto the glacier surface. 
As a final step, we remove all the glaciers from the domain to give an insight on the changed land-atmosphere exchange. The removed glaciers lead to a complete change from a partly stable glacier boundary layer to a convective valley boundary layer disturbed by weaker gravity waves.
This numerical study tries to untangle the processes behind thermally- and dynamically-driven flows in an complex environment and gives possible scenarios for "what to expect” in terms of boundary layer and mesoscale dynamics in a future ice-free catchment area.