Modeling the mass balance of tropical Lewis Glacier, Mt Kenya, and its sensitivity to climate

Meteorological and glaciological measurements on Lewis Glacier, Mt Kenya, (0.15° S, 37.30° E) are used to run a physically-based mass balance model for the two years period September 2009 to September 2011. Data for input, optimization and validation are provided by an automatic weather station (~4830 m) installed on the glacier and a network of ablation stakes. On a local scale, sensitivity studies allow the detection of the main drivers of the energy balance of the glacier surface. A focus is put on energy fluxes governed by the seasonal fluctuations of moisture (wet / dry seasons). On a more regional scale, decoding the local glacier-atmosphere interaction is crucial to understand the regional climate forcing which provides the basis to explain the rapid retreat of Lewis Glacier observed over almost a century.