Surface Emissivity and Temperature Profile Retrieval over Sea Ice

Polar regions play a key role in the global climate. The information on atmospheric parameters in these regions is sparse. In order to derive atmospheric parameters such as temperature and humidity profiles from spaceborne radiometers, the surface emissivity of Polar Regions is needed. Among the polar surfaces, sea ice varies in extent and physical properties with region and season and so does the surface emissivity.

The retrieval of surface emissivity of sea ice is done by combining simulated brightness temperatures with the satellite measured brightness temperature. In order to determine the surface emissivity of sea ice, the observations of the microwave instruments AMSU (Advanced Microwave Sounding Unit) and AMSR-E (Advanced Microwave Scanning Radiometer- Earth Observing System) are used.

Determination of emissivity requires the knowledge of the temperature of the emitting layer. They are derived from lowest level air temperature. The method accounts for the variation of the penetration depth with frequency, air temperature and sea ice temperature.

An algorithm to retrieve temperature profiles from AMSU data is modified using the retrieved emissivities and the derived temperature correction factors so that the retrieval accuracy of temperature profiles over sea ice can be improved.

Datum

25.07.2007

Uhrzeit

13:30 Uhr

Ort

Bundesstr. 53, room 022/023
Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg

ReferentIn

Nizy Mathew, Institute of Environmental Physics, University of Bremen

Chair


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