Helicopter-borne GPR for mapping snow accumulation distribution

Snow accumulation and its spatial distribution is highly important for many components of the cryosphere (e.g. glacier mass balance, permafrost active layer), but also determines the hydrological regime of mountainous catchments. It is thus crucial for water resource management. In high-alpine terrain snow depth can vary by one order of magnitude over distances of a few meters. This variability can not yet be adequately captured by numerical models, and measurements of snow depth distribution in the field are laborious. Therefore, tools for easily identifying snow depth are required and would contribute to a better understanding of the high variability of snow accumulation in space.

This project will apply and further develop Ground Penetrating Radar (GPR) techniques for detecting the snow depth distribution on glaciers. The GPR system will be based on a helicopter thus allowing a fast, remote and reliable monitoring of snow accumulation in high alpine terrain. This allows an accurate mapping of the pattern of spatial variability in the snow cover. The helicopter-borne GPR technology is applied at two glacierized test sites (Findelengletscher and Colle Gnifetti on Grenzgletscher, Valais). GPR measurement campaigns are accompanied by extensive ground-based validation of the results (snow density measurements, firn cores etc) for assessing the uncertainties. Furthermore, the potential of helicopter-borne GPR to detect firn layers of previous years, and thus past accumulation rates on alpine glaciers are investigated in detail.

The project focuses on the potential of helicopter-borne GPR in glaciology and develops methods for standardized evaluation of the field data. In addition, new modelling approaches to calculate the spatial distribution of snow accumulation on glaciers are developed based on the process understanding gained from the high-resolution field data. This will contribute to enhance current glacier mass balance models, and allows advances in glacier monitoring and the prediction of the future change in alpine glaciers.

• Publications
  • Sold L., Huss M., Machguth H., Joerg P. C., Leysinger Vieli G., Linsbauer A., Salzmann N., Zemp M., HoelzleM. (2016), Mass balance re-analysis of Findelengletscher, Switzerland; benefits of extensive snow accumulation measurements, in Frontiers in Earth Science, 4(18), 1-16.
  • Sold L., Huss M., Eichler A., Schwikowski M., Hoelzle M. (2015), Unlocking annual firn layer water equivalents from ground-penetrating radar data on an Alpine glacier, in The Cryosphere Discussion, 9(3), 1075-1087.
  • Sold Leo, Huss Matthias, Hoelzle Martin, Andereggen Hubert, Joerg Philipp, Zemp Michael (2013), Methodological approaches to infer end-of-winter snow distribution on alpine glaciers, in Journal of Glaciology, 59(218), 1047-1059.
  • Sold L., Eichler A., Hoelzle M., Huss M., Schwikowski M. (2013), Recent accumulation rates on Findelengletscher derived from airborne GPR and firn cores.
  • Huss M., Sold L., Hoelzle M., Stokvis M., Salzmann N., Farinotti D., Zemp M. (2013), Towards remote monitoring of sub-seasonal glacier mass balance, in Annals of Glaciology, 54(63), 85-93.
  • Eichler A., Eikenberg J., Ruthi M., Sold L., Hoelzle M., Schwikowski M. (2013), Tritium fallout from Fukushima accident in Switzland?.
  • Sold L., Huss M., Eichler A., Schwikowski M., Hoelzle M., Recent accumulation rates of an alpine glacier derived from firn cores and repeated helicopte-borne GPR, in The Cryosphere Discussion, 8(4), 4431-4462.