Abstract's details

What can we learn about nearshore dynamics from spatial altimetry ? : preliminary results from the TOSCA/POSPOW project

Yann Krien (LEGOS, University of Toulouse, France)

Florence Birol (LEGOS, France); Jamal Khan (LEGOS, IRD, France)

Event: 2025 SWOT Science Team Meeting

Session: Deltas, Estuaries and Coasts

Presentation type: Poster

Improving our understanding of hydrodynamics very close to the shore -at depths of just a few meters- is crucial for better predicting and anticipating coastal flooding, shoreline erosion, and pollutant transport. While spatial altimetry has proven effective in accurately measuring water levels or waves in coastal areas, it generally remains limited to distances several kilometers offshore, and has yet not been used to investigate dynamics in the surf zone, where wind waves strongly interact with the bottom. The emergence of new technologies on recent space missions such as SWOT has the potential to change this situation.

As part of the CNES-funded TOSCA/POSPOW project, we are taking advantage of the exceptional morphological features of a unique geographical region -the Ganges delta- to explore the potential of spatial altimetry to capture hydrodynamic processes in the surf zone. The Ganges delta is indeed characterized by an exceptionally flat clinoform, resulting in water depths of less than 10 meters even tens of kilometers offshore.

Building upon a decade of work conducted by the POSPOW team in the study area, that resulted in particular in a state-of-the-art 3D wave-current coupled numerical model, we conduct intercomparisons between altimetric data (SWOT, LRM), numerical reanalysis, and estimates of currents or wave heights derived from alternative methods such as Doppler shift (Sentinel 1) and optical imagery (Sentinel 2).

We will present very preliminary results of these intercomparisons that demonstrate the potential of SWOT to capture physical processes in nearshore waters, and also point the way for future improvements.

Corresponding author:

Yann Krien

LEGOS, University of Toulouse

France

yann.krien@univ-tlse3.fr

Poster show times:

Room Start Date End Date
Poster session part 1 Tue, Oct 14 2025,18:00 Tue, Oct 14 2025,21:00
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