Partner und Internationale Organisationen
(Englisch)
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Dept. of Geophysics, University of Bologna, Groupe de Recherche de Géodésie Spatiale, Toulouse, Bundesamt für Kartographie und Geodäsie, Frankfurt/M., Inst. f. Geophysik, Christian-Albrecht-Universität, Kiel Dionysos Satellite Obs., Nat. Techn. University, Athens
Proudman Oceanographic Laboratory, Merseyside, UK, Dept. de Fisica Aplicada, Universidad de Cadiz, Spain, Moscow State University, Moscow, Bulgarian Academy of Sciences, Sofia
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Abstract
(Englisch)
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The objective of this project is to assess sea level changes using tide gauge recordings at coastal sites around the Mediterranean Sea. The ultimate goal is to provide basic data for studying sea level changes in connection with climate changes. The project is carried out in the framework of the European SEa Level Fluctuation program, SELFII. One of the key problems in this project was the separation of vertical crustal movements of the tide gauge sites from the long-term signals of the relative sea level records. In addition, the tide gauge sites have to be connected by using a global reference system. The method which provides this information is based on Radiowave (GPS) ranging techniques. The main limiting factor for the determination of the height components using GPS is the tropospheric refraction. Modeling of the water vapor content is particularly difficult because of its high spatial and temporal variability. Therefore, water vapor radiometers were developed and deployed to determine the effects of the wet component of the troposphere. Experiments have revealed differential path delays of the GPS radio signals on the order of several cm [Sierk et al., 1997]. The determination of the wet component and its consideration for assessing the portion of long-term sea level changes in tidal gauge recordings was a prime contribution of the Geodesy and Geodynamics Lab (GGL, ETH Zürich). The second objective was to determine spatial variations of the sea-surface topography in the Ionian Sea from airborne Laser profiling, and connect it with results from Satellite Radar Altimetry.
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