Improving the reconstruction of upper ocean dynamics from space

Final presentation of research fellow Florian Le Guillou.

Abstract:

The use of satellite data has revolutionized the study of upper ocean dynamics, offering global, continuous, and real-time information about various physical processes at the ocean’s surface. These data provide key insights into ocean circulation, temperature distribution, wave patterns, and other dynamic factors. For instance, Sea Surface Height (SSH), observed by altimetry, is a key variable for monitoring ocean circulation. Similarly, Sea Surface Temperature (SST) serves as a crucial indicator of heat exchange between the ocean and atmosphere.

Typically, scientific, and operational applications require gap-free, gridded satellite data (L4 products). However, operational algorithms often depend on basic interpolation techniques applied to L3 satellite data, which tend to filter out fine-scale processes. In this presentation, I will introduce a hybrid methodology which combines minimal physically based constraints with a variational scheme to enhance the mapping capabilities of upper ocean dynamics. By synthesizing multi-modal satellite observations, the method improves the accuracy and resolution of SSH and SST maps in comparison to operational products. Applications of the method will be discussed, including the reconstruction of 3D dynamics from surface data, the refinement of SSH climate records, and the estimation of air-sea fluxes.