Jean-Charles Gallet

Forsker, snøfysikk
Jean-Charles Gallet
Norsk Polarinstitutt

My work focuses on snow and its interaction with the atmosphere, especially the radiative processes between the incoming solar light and the snow surface. Snow is one of the most, or perhaps even the most reflective surface on Earth so that its albedo is a key parameter to determine the planetary energy budget. The albedo is of snow is essentially determined by the size of the snow grain and by its impurity content such as black carbon, dust, volcanic ash, algae ...

I am especially focused on the determination of the specific surface area (SSA) of snow. The SSA is the surface area per unit of mass and is expressed in m 2 kg -1. Contrary to the snow grain size that is often determined in the field and which is observer dependent, the snow SSA is non-ambiguous and can be easily measured in the field using optical instruments. I have also been working on the determination of the black carbon content of the snowpack and its effect on the albedo of snow using field measurement and modeling calculations (DISORT, radiative transfer model).

I have done work on the Antarctic plateau at Dome C, in Barrow, Alaska, and in the French Alps. Currently my work is focused on the Arctic area (Svalbard archipelago) and China (north-east). I am mostly interested in snow on land, glaciers and ice caps, but have also done some work on snow on sea-ice.