Abstract's details

Evaluating the impact of SWOT assimilation in Mercator Ocean International’s forecasting system: insights from AdAC campaigns

Ergane Fouchet (Ergane FOUCHET, France)

Mounir Benkiran (Mercator Ocean International, France); Pierre-Yves Le Traon (Mercator Ocean International, France)

Event: 2025 SWOT Science Team Meeting

Session: Oceanography: Regional Validation

Presentation type: Poster

Many social and economic sectors directly depend on the ability to describe and predict ocean conditions at any time, location, and depth. With its unprecedented spatial resolution, the SWOT mission now enables global measurements of sea surface height (SSH) and the characterization of ocean dynamics down to the submesoscale. However, ocean models and data assimilation systems remain essential to dynamically propagate this surface information in time, in depth, and across other physical variables. Assimilating SWOT KaRIn global, high-resolution, and two-dimensional SSH observations thus offers strong potential for improving the representation and forecasting of small mesoscale features.

Ahead of the operational assimilation of SWOT Science Phase data into Copernicus Marine products, we analyze the response of the Mercator Ocean assimilation system to three months of daily observations from the Cal/Val phase. Our assessment is based on comparisons with in situ measurements from the SWOT-AdAC Consortium, which deployed a wide range of instruments directly beneath the satellite tracks. We focus on the QUICCHE and SMODE campaigns, in the Agulhas and California Currents respectively, to evaluate the assimilation of SWOT in dynamically different regions.

Surface drifters provide high-temporal-resolution trajectories and velocities, capturing a broad spectrum of ocean motions across scales. They are besides independent of both the model and assimilated satellite data, making them a valuable reference for model validation. We compare observed drifter trajectories with those of virtual Lagrangian particles seeded in the model velocity fields, both with and without SWOT assimilation. This approach allows us to assess the added value of SWOT assimilation for surface current dynamics and transport.

Contribution: ST2025OS2-Evaluating_the_impact_of_SWOT_assimilation_in_Mercator_Ocean_International_s_forecasting_system__insights_from_AdAC_campaigns.pdf (pdf, 2868 ko)

Corresponding author:

Ergane Fouchet

Ergane FOUCHET

France

efouchet@mercator-ocean.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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