Abstract's details
ADVANCING MARINE GRAVITY FIELD RECOVERY IN THE BAY OF BENGAL USING SURFACE WATER AND OCEAN TOPOGRAPHY ALTIMETRY DATA
Event: 2025 SWOT Science Team Meeting
Session: Oceanography: Mean Sea Surface
Presentation type: Oral
Recovering the marine gravity field from satellite altimetry is essential for geoid modeling and for understanding ocean circulation, tectonic activity, seabed dynamics, and seafloor topography. Among available techniques, the Inverse Vening Meinesz Method (IVM)—which utilizes Deflection of the Vertical (DoV) components—has proven to be a robust alternative to the Inverse Stokes’ Integral Method (ISM), which relies on geoid heights. The accuracy of the IVM method is highly dependent on the precision of the DoV inputs.
This study enhances marine gravity field estimation in the Bay of Bengal using the IVM, with DoV components derived from observations collected over 19 cycles of the Surface Water and Ocean Topography (SWOT) mission. Unlike earlier studies limited to simulated or single-cycle SWOT data, this work significantly improves temporal coverage and captures both static and dynamic gravity features. High-resolution DoV components were computed on a fine spatial grid, targeting improved precision in the recovered gravity field.
Validation is performed using shipborne gravity data and comparisons with established global gravity models, including EGM2008, SSv29.1, and DTU21GRA. To further ensure reliability, the SWOT-derived results are cross-validated with data from other satellite altimetry missions (e.g., Jason series, CryoSat-2). This multi-mission integration leverages SWOT's high spatial resolution and the long-term consistency of traditional altimeters, facilitating both bias correction and enhanced temporal coverage.
Building upon prior work in the Bay of Bengal, this study demonstrates the benefits of multi-cycle SWOT data in refining marine gravity estimates. The results are expected to significantly improve regional geoid modeling and offer insights into subsurface density variations. The proposed methodology is also adaptable to other geophysically complex regions, laying a foundation for broader application across the Indian Ocean, particularly in areas with weak geoid signals.
This research helps advance marine geophysics by showing how SWOT data can be used effectively to recover gravity fields. The findings support enhanced oceanographic studies, improved navigation, and a more profound understanding of the interactions between oceanic and geophysical processes in coastal regions.
Keywords: Surface Water and Ocean Topography, Bay of Bengal, Marine Gravity, Deflection of the Vertical, Satellite Altimetry, Gravity Field Recovery
Back to the list of abstractThis study enhances marine gravity field estimation in the Bay of Bengal using the IVM, with DoV components derived from observations collected over 19 cycles of the Surface Water and Ocean Topography (SWOT) mission. Unlike earlier studies limited to simulated or single-cycle SWOT data, this work significantly improves temporal coverage and captures both static and dynamic gravity features. High-resolution DoV components were computed on a fine spatial grid, targeting improved precision in the recovered gravity field.
Validation is performed using shipborne gravity data and comparisons with established global gravity models, including EGM2008, SSv29.1, and DTU21GRA. To further ensure reliability, the SWOT-derived results are cross-validated with data from other satellite altimetry missions (e.g., Jason series, CryoSat-2). This multi-mission integration leverages SWOT's high spatial resolution and the long-term consistency of traditional altimeters, facilitating both bias correction and enhanced temporal coverage.
Building upon prior work in the Bay of Bengal, this study demonstrates the benefits of multi-cycle SWOT data in refining marine gravity estimates. The results are expected to significantly improve regional geoid modeling and offer insights into subsurface density variations. The proposed methodology is also adaptable to other geophysically complex regions, laying a foundation for broader application across the Indian Ocean, particularly in areas with weak geoid signals.
This research helps advance marine geophysics by showing how SWOT data can be used effectively to recover gravity fields. The findings support enhanced oceanographic studies, improved navigation, and a more profound understanding of the interactions between oceanic and geophysical processes in coastal regions.
Keywords: Surface Water and Ocean Topography, Bay of Bengal, Marine Gravity, Deflection of the Vertical, Satellite Altimetry, Gravity Field Recovery