Filtering Internal Tides From Wide-Swath Altimeter Data Using Convolutional Neural Networks

• Main Authors: Lguensat, Redouane, Fablet, Ronan, Sommer, Julien Le, Metref, Sammy, Cosme, Emmanuel, Ouenniche, Kaouther, Drumetz, Lucas, Gula, Jonathan
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: arXiv 2020
• Subjects: Atmospheric and Oceanic Physics physics.ao-ph; Machine Learning cs.LG; Image and Video Processing eess.IV; Signal Processing eess.SP; FOS Physical sciences; FOS Computer and information sciences; FOS Electrical engineering, electronic engineering, information engineering; North Atlantic
• Online Access: https://dx.doi.org/10.48550/arxiv.2005.01090; https://arxiv.org/abs/2005.01090

The upcoming Surface Water Ocean Topography (SWOT) satellite altimetry mission is expected to yield two-dimensional high-resolution measurements of Sea Surface Height (SSH), thus allowing for a better characterization of the mesoscale and submesoscale eddy field. However, to fulfill the promises of this mission, filtering the tidal component of the SSH measurements is necessary. This challenging problem is crucial since the posterior studies done by physical oceanographers using SWOT data will depend heavily on the selected filtering schemes. In this paper, we cast this problem into a supervised learning framework and propose the use of convolutional neural networks (ConvNets) to estimate fields free of internal tide signals. Numerical experiments based on an advanced North Atlantic simulation of the ocean circulation (eNATL60) show that our ConvNet considerably reduces the imprint of the internal waves in SSH data even in regions unseen by the neural network. We also investigate the relevance of considering additional data from other sea surface variables such as sea surface temperature (SST). : Accepted for publication in IEEE IGARSS 2020 conference