Klaus-Peter Johnsen
Institute of Environmental Physics
University of Bremen
P.O. Box 330440, D-28334 Bremen
Tel.+49 421 218-2584, Fax -4555,
e-mail: johnsen@diana.physik.uni-bremen.de

Klaus-Peter Johnsen, born in 1967, Diplomphysiker (Technical University of Braunschweig, 1994),

Ph.D. (University of Bremen, 1998).

Since 1995 he is with the Institute of Environmental Physics, University of Bremen, where he has finished his PhD.-thesis 'Radiometric measurements in the Arctic ocean - comparison between theory and experiment' in 1998. He took part in the Polarstern cruise ARK XII and has taken passive microwave in situ measurements of sea ice in the Kara- and Laptevsea. His research interests are in the fields of remote sensing of cryospheric surface with passive microwave and other sensors. He has developed with colleagues a combined emissivity model of (ice covered) sea surface and atmosphere ( ESA, 1994-96).

Activities in radiative transfer calculations.

A. Darovskikh, K.-P.Johnsen, V.Fedotov, K.Tyshko, H.Eicken, G.Heygster Growth velocity of freshwater ice and air bubble sizes linked to microwave radiometer measurements. in: Ice in Surface Waters. Proceedings of the 14th International Symposium on Ice, Editor: Hung Tao Shen, Vol.1, 391-395, Potsdam, New York, USA, 1998

K.-P. Johnsen, A.Darovskikh, G.Heygster, A.Wiesmann: Microwave Measurements of Sea Ice in the Kara- and Laptev Sea. Proceedings of the IGARSS'97, 3.-8.8.1997, Singapur, IEEE Catalog No.97CH36042, 1675--1677, 1997

K.-P.Johnsen, G. Heygster, A. Darovskikh, Interference effects in freshwater and sea ice - theory and experiment, Submitted to IEEE Transaction on Geoscience and Remote Sensing, Institut fuer Umweltphysik, Universitaet Bremen, 1998

K.-P.Johnsen, G. Heygster, A. Darovskikh, 1998: Microwave radiometer measurements of sea ice and freshwater ice in experiment and theory -Submitted to IEEE Transactions on Antennas and Propagation.

R.Fuhrhop, T.C.Grenfell, G.Heygster, K.-P.Johnsen, P.Schluessel, M. Schrader, C.Simmer, 1998 -- A combined radiative transfer model for sea ice, open ocean, and atmosphere. Radio Science, Vol.3, No.2, 303-316.

Role in the SMOS mission:

Exploiting the high spatial resolution of the 1.4 GHz channel in combination with the low influence of the atmosphere we will analyze the possibility to improve the detection of the ice concentration and ice drift. For comparisons and synergy the AMSR and the SSM/I will be used.

With microwave emissivity models we will analyse the influence of the salinity in sea ice to the radiometric signal. According to preliminary studies it should be possible to determine the ice thickness for areas of low salinity. Development of a retrieval scheme.