Ocean transports, Evaporation-Precipitation and run-off estimated through the GECCO Reanalysis

A. Köhl and D. Stammer

The goal of this project is to quantify freshwater fluxes in the ocean, and improve our understanding of their temporal and spatial changes in terms of the interaction between ocean transport processes, surface net freshwater fluxes and river run-off, as well as mixing processes in the ocean. In particular, we aim at combining all available ocean salinity/freshwater data (including novel satellite-based salinity retrievals and ARGO data), surface freshwater fluxes (including HOAPS and NCEP net surface freshwater fluxes) and river discharge with a numerical model to improve our understanding of net surface sources of freshwater, near-surface freshwater budgets, and full-depth ocean freshwater transports.

Respective sub-goals entail:

  • Improving the quality of SMOS and Aquarius surface salinity data and estimating respective error information required for their subsequent analysis and assimilation.
  • Expansion of the GECCO data assimilation system to incorporate surface salinity fields.
  • Evaluation of the sensitivity of subsurface salinity to freshwater fluxes (incl. run-off), surface salinity fields and subsurface salinity changes.
  • Estimates of surface and subsurface salinity fields, ocean transports of freshwater (including surface freshwater fluxes) from monthly mean SMOS and Aquarius fields, ARGO salinities and underway salinity measurements.
  • Quantifying the role of surface forcing (E-P-R) versus lateral transports and mixing of freshwater in modulating the freshwater content as function of depths and geographical position.

Providing a best possible description of salinity changes and underlying processes in the Atlantic Ocean.

Picture: The SMOS satellite in space.