Controls on spatial and temporal variations in the snowpack of a High Arctic ice cap: Devon Island Ice Cap, Nunavut, Canada

This project aims to determine the key processes responsible for creating spatial and temporal variations in snowpack structure across High Arctic ice caps. Variations in rates of accumulation, surface melting, percolation and refreezing within the snowpack create a range of different annual snowpack characteristics across the accumulation areas of ice caps. A better understanding of these processes is important not least because of the crucial contribution of meltwater retention by refreezing to the surface mass balance of arctic ice masses. Variations in snowpack structure also make the derivation of ice amss elevation change from airborne and satellite radar measurements problematic since seasonally produced internal ice layers and ice lenses may generate stronger reflectors than the snow surface. Without knowledge of controls on such short term (seasonal - annual) variability, identification of longer term trends remains open to misinterpretation. This project addresses these concerns, focussing on a 45 km long transect of Devon Island Ice Cap, by (a) identifying structural change in snowpack stratigraphy from field measurements taken across several snow facies, before and after the summer melt season (Spring and Autumn 2004, 2006); (b) monitoring meterological conditions at 4 elevations along the transect over a 2.5 year period (including air temperature, accumulation, wind speed/direction, incoming solar radiation, and relative humidity); and by (c) using these data to test and develop existing energy balance models and thereby determine key processes controlling snowpack evolution across a High Arctic ice mass. Work is being carried out as part of the calibration/validation effort of the European Space Agency's CryoSat mission due for launch in summer 2005.