Heidrun Wiebe

Name:              Heidrun Wiebe (ESSReS PhD student)
Institute:          IUP Uni Bremen
Department:     Remote Sensing (group: PHAROS)
Phone:             +49-(0)421-218-4274
Email:              hwiebe(at)uni-bremen.de
Web link:         http://www.iup.uni-bremen.de/iuppage/satellite_index.html

PhD-project title: Combination of microwave and optical satellite data for remote sensing of snow and sea ice.

Observations of sea ice and snow cover in polar regions are very important for climate modelling. Satellite remote sensing techniques offer to monitor these quantities on a global scale. Sea ice monitoring is typically done by microwave sensors, for the snow cover optical sensors are most suited.

Sea ice plays an important role for the oceanic circulation. During the formation of sea ice, salt is released to the surrounding water. The water becomes dense and sinks down. This process drives the thermohaline circulation.

Snow fields have potentially significant effects on the energy balance of the Earth due to the high albedo of snow. The retreat of snow cover would lead to more absorption of solar radiation, which would further reduce the snow cover. The albedo of snow is mainly dependent on snow grain size (larger grains have lower albedo) and soot pollution (higher amounts of soot reduce the albedo).

The goal of this doctoral thesis is to combine microwave and optical satellite data for sea ice monitoring and to retrieve the grain size and soot pollution of the snow from optical data. The latter requires to preprocess the data in terms of a) separating snow pixels from non-snow pixels (e.g. water, cloud, vegetation), and b) applying atmospheric corrections due to aerosols and atmospheric gases in the atmosphere.

Start of doctoral thesis: 01.06.2008

Thesis Committee:

Prof. Dr. J. Notholt (IUP University Bremen)
Dr. G. Heygster (IUP University Bremen)