Regional coastal sea level change and sea level topography from altimetry, oceanography, and tide gauge stations in Europe

• Applicant: Professor Dr.-Ing. Matthias Becker
• Subject Area: Geophysics
• Term: from 2007 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 26374204

Coastal Areas are one of major challenges for Satellite Altimetry due to deterioration of altimeter signals and environmental corrections to altimetry near to the coast. The use of altimetry data in combination with tide gauge data for satellite altimeter calibration, sea level variability (SLV) determination and mutual validation of trends in sea levels is hindered by these coastal effects.Topic of the proposal is the improved estimation of sea level variability in coastal areas. The aim is twofold a) to monitor the long-term sea level variability and b) to assess the applicability of altimeter techniques in coastal/marginal regions. Two regions with complementary characteristics are selected, namely the Gulf of Biscay on the Atlantic Ocean shelf and the north-western Mediterranean Sea in the semi-enclosed Mediterranean Sea basin.The work is based on newly available altimetry data at high frequency (10 Hz of higher) and on improved altimeter corrections better suitable for coastal areas. With a combination of local corrections and dedicated waveform processing the accuracy of altimetric measurements in coastal region shall be improved. The standard 1-Hz data will be used and analyzed in addition. The combination of multi-satellite altimetry and tide gauge data shall improve the spatial and temporal resolution of the estimated sea level variability. The regional unification of multi-satellite altimeter data is addressed and discrepancies in the sea level height measurements are investigated. Tide gauge station data are used as ground truth to investigate both variability and absolute location of the sea level measurements. Correction from local barotropic and oceanographic models and of residual tidal effects from local tidal models are used in addition to mean sea level and geoid models to improve the agreement between altimetry and tide gauge measurements.In the framework of this project methodologies will be developed to construct improved models of sea level variability and of mean dynamic topography by optimally combing the new altimetry dataset and the heterogeneous data from tide gauges and oceanographic models.

• DFG Programme: Research Grants