Wind driven snow accumulation variability and terrain : Establishing a relationship by using GPR on Svalbard.

Snow accumulation patterns can be highly variable depending on terrain and wind. Knowledge of spatial variability of snow accumulation is of high relevance for mass balance modelling. By not incorporating the variability in snow cover, the estimation in mass fluxes and the surface melt are incorrect...

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Bibliographic Details
Main Author: Heerema, Catharina
Format: Bachelor Thesis
Language:English
Published: Uppsala universitet, Institutionen för geovetenskaper 2016
Subjects:
GPR
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303875
Description
Summary:Snow accumulation patterns can be highly variable depending on terrain and wind. Knowledge of spatial variability of snow accumulation is of high relevance for mass balance modelling. By not incorporating the variability in snow cover, the estimation in mass fluxes and the surface melt are incorrectly presented, affecting the eventual estimation of for instance contribution to sea level rise. Additionally, knowledge of snow accumulation variability is essential for assessing the reliability of point-wise mass balance measurements. Using ground penetrating radar (GPR), the spatial variability of snow can be mapped with both a great spatial and temporal resolution. GPR enables tracing of summer surface melt layers, resulting in a 2D reconstruction of past snow accumulation and associated variability. GPR measurements have been done on Svalbard, during 2012, 2013 and 2014. Based on the selected 2009 summer surface in the GPR measurements, accumulation rates were estimated between 2009-2012; 2009-2013 and 2009-2014. In addition, several terrain parameters are computed by combining DEM calculations with wind direction, resulting in a sheltering index, slope and curvature. We explore relationships between the found accumulation pattern and the terrain parameters with varying wind directions. Correlations between terrain and accumulation depend on the selected wind angle, which appears to change with elevation. The results suggest that localized wind patterns prevail on the glacier and shape the snow cover. Katabatic winds form at low elevations on the glacier and are oriented in the glacier direction of approximately 20 degrees. At intermediate elevation, winds from the east-southeast regulate the accumulation pattern. On the upper parts of the glacier, the terrain is more exposed and winds from large-scale atmospheric circulation, at 240 degrees, become more important in formation of the snow accumulation pattern. Correlations are overall high, indicating a strong influence of terrain features on the accumulation ...