Reconstructing the 4D Thermohaline Field in the Gulf of Mexico from Argo Float Data Using Geostrophic Stream-Function Projections

The variability of the Loop Current has been extensively studied due to its influence on the energy and heat distribution in the Gulf of Mexico, which in turn impacts both the oil industry and hurricane forecasting. Improving the predictability of the Loop Current's path and the detachment of its eddies requires a better understanding of the thermohaline structure, which has driven the deployment of numerous Argo profiling buoys in the eastern Gulf over the past decade. Despite these efforts, significant gaps remain in both the temporal and spatial coverage of in situ observations. Several methods have been developed to address these gaps by generating vertical projections from surface data, combining remote sensing information with available hydrographic profiles. In this study, the satGEM (satellite-Gravest Empirical Mode, Meijers et al., 2011) method is applied to project profile data onto geostrophic stream-function space, the latter being the absolute dynamic topography derived from satellite data. The performance of this method in reproducing thermohaline profiles under various dynamic conditions of the Loop Current and its eddies is compared with other vertical projection techniques currently used in the region, including both empirical methods (such as those based on Machine Learning) as well as hydrodynamical models with data assimilation.