SAR altimetry in the Gulf of Bengal

Luciana Fenoglio-Marc (University of Bonn, Germany)

CoAuthors

Bernd Uebbing (University of Bonn, Germany); Christopher Buchhaupt (Technical University Darmstadt, Germany); Salvatore Dinardo (EUMETSAT, Germany); Remko Scharroo (EUMETSAT, Germany); M. Joana Fernandes (University of Porto, Portugal); Jürgen Kusche (University of Bonn, Germany); Haque Khan (Institute of Water Modelling, Bangladesh); Matthias Becker (Technical University Darmstadt, Germany)

Event: 2016 SAR Altimetry Workshop

Session: Applications, SAR for science

Presentation type: Type Oral

Sea level in the Bay of Bengal is perceived as a major threat to the densely populated coastal areas due to land subsidence, absolute sea level rise rates higher than the global mean and frequent cyclones.

Sea level change is here measured from SAR and pulse-limited satellite altimetry in the interval 2012 to 2016. Our goal is to investigate the additional knowledge that SAR altimetry from the Cryosat-2 and Sentinel-3 missions can eventually provide. We use CryoSat-2 and Sentinel-3 data in SAR mode, as well as conventional Jason-2 and SARAL-AltiKa low resolution mode (LRM) data. Cryosat-2 SAR data are from GPOD and Sentinel-3 data from EUMETSAT. The FBR data are processed to generate Reduced SAR (RDSAR) 20 Hz waveforms. RDSAR and LRM waveforms are retracked using various algorithms.

The accuracy of some environmental corrections to the altimetric measurement to derive sea level is expected to be low due to lacking of in-situ data and due to the intrinsic characteristics of the natural signal itself. Wet tropospheric correction from on-board microwave radiometer, model-derived and GPD+ from UPorto are here compared as well as the resulting sea level data.

SAR-derived parameters are evaluated by using in-situ hourly tide gauge data from the University of Hawaii Sea level Center, wind and wave models from European Centre for Medium-Range Weather Forecasts and from Wave Watch 3. Through the BanD-Aid consortium (Belmont Forum) additional tide gauges and modelled water levels are made available from the operational forecast system of the Institute of Water Modelling (IWM) in Bangladesh.

Spatially averaged and gridded monthly sea level variability and trends computed from SAR altimetry are compared to state of the art sea level datasets as the Climate Change Initiative ECV products and to monthly tide gauges of the Permanent Service of Mean Sea level. Finally swell and cyclonic events are investigated to detect differences between SAR and RDSAR observations.
 

Oral presentation show times:

RoomStart DateEnd Date
Auditorium Mon, Oct 31 2016,17:15 Mon, Oct 31 2016,17:30
Luciana Fenoglio-Marc
University of Bonn
Germany
fenoglio@psg.tu-darmstadt.de