Signal formation in snow and firn: Combining surface topography data and stable water isotopes

• Main Authors: Zuhr, Alexandra, Hörhold, Maria, Steen-Larsen, Hans Christian, Münch, Thomas, Kipfstuhl, Sepp, Laepple, Thomas
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: Greenland; East Greenland
• Online Access: https://epic.awi.de/id/eprint/48649/; https://hdl.handle.net/10013/epic.e39c8d9c-1c53-4b51-98ed-0a8a7f384960

Ice sheets represent one of the main reservoirs in the global climate system archiving information on past climatic conditions. The isotopic composition of stable water isotopes of ice sheets can be used as a temperature proxy and allows the reconstruction of past climates. However, measured isotopic compositions from precipitation differ strongly from surface snow samples. Thus, non-climatic effects (e.g. wind-redistribution) alter the isotopic composition after the deposition. In order to investigate the evolution of the isotopic composition in the upper firn layer (top 10cm) we carried out a comprehensive sampling scheme along a 40m transect throughout the full season at the deep drilling site in North-East Greenland, EastGRIP. Additionally, we tracked snow accumulation with a new method using daily photos to develop elevation models of the snow surface. The evolution of the isotopic composition from the precipitation via the deposition on the snow to the upper firn layer together with information on changes in topography (i.e. the net accumulation based on the photos) allow us to investigate possible relations between these parameters. Complementing this new data set with data from the previous seasons, we aim to investigate the evolution of this temperature proxy with depth and time.