Long-term interactions between snow and the atmosphere in the Arctic

Climate assessments consistently reproduce zonal mean surface
temperature warming in Arctic latitudes exceeding the global average.
This Arctic Amplification was initially attributed to snow/ice albedo
feedbacks, but progressing climate modeling revealed several other
feedbacks playing a role as well. These include effects due to modified
thermal properties of sea ice or changes in poleward energy transport
and associated shifts in storm tracks, vapor and clouds. These findings
are mostly based on climate modeling, but their validation by
observations as well as the assessment of the relative importance of
inherent processes remains difficult and is still quite controversially
discussed. Based on this background, this project seeks to investigate
the role of long-term snow developments and of inherent feedbacks due to
e.g. changes in snow structure and snow albedo in Arctic
Amplification in more detail. Albedo changes are at least partly related to the incorporation of light absorbing impurities and, thus, the chemical composition of the snow. Therefore, a second objective is related to a better understanding about chemical interactions between the atmosphere and the snow including pollutant wet/dry deposition and pollutant recycling at the snow/ice-atmosphere interface.