Berlin 2014 – wissenschaftliches Programm

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UP: Fachverband Umweltphysik

UP 11: Postersession

UP 11.13: Poster

Mittwoch, 19. März 2014, 17:00–18:30, MAG Poster

Determination of sea ice concentration during summer using 1.4 GHz brightness temperatures — •Valentin Ludwig¹ and Lars Kaleschke² — ¹Raum 020, Institut für Meereskunde, Universität Hamburg, Bundesstraße 53, ZMAW-Gebäude, 20146 Hamburg — ²Raum 016, Institut für Meereskunde, Universität Hamburg, Bundesstraße 53, ZMAW-Gebäude, 20146 Hamburg

An algorithm for the sea ice concentration retrieval from passive microwave data acquired in the protected frequency band of 1400-1427 MHz (L-band) was developed. It had been hypothesised that the wide range between the emissivities of open water and sea ice in L-band causes a high sensitivity towards low and intermediate ice concentrations. Previously used sensors had shown large uncertainties in low ice concentrations or were not even able to measure them at all. Additionally, the atmospheric influence can mostly be neglected in L-band. The results of this study indeed indicate the potential of the Soil Moisture and Ocean Salinity (SMOS) satellite in showing lower, physically consistent, sea ice concentrations than the Special Sensor Microwave/Imager (SSM/I) during the melting period 2012. Sea ice concentration uncertainties were found to be low for low and intermediate sea ice concentrations. A validation with Moderate Resolution Imaging Spectrometer (MODIS) infrared images shows good agreement with SMOS in low and intermediate ice concentrations. SMOS tends to underestimate high sea ice concentrations which exceed 80%. Additionally, clear 100% - 0% sea ice concentration jumps are smeared out due to the coarse spatial resolution.