Multi-Modal Learning-based Reconstruction of High-Resolution Spatial Wind Speed Fields

• Published in: Environmental Data Science pp. 1 - 21
• Main Authors: Zambra, Matteo, Farrugia, Nicolas, Cazau, Dorian, Gensse, Alexandre, Fablet, Ronan
• Format: Journal Article
• Language: English
• Published: Cambridge University Press 2024
• Subjects: Engineering Sciences; Signal and Image processing; FOS: Computer and information sciences; Atmospheric and Oceanic Physics (physics.ao-ph); FOS: Physical sciences; Machine Learning (cs.LG); Computational Physics (physics.comp-ph)
• ISSN: 2634-4602

Wind speed at sea surface is a key quantity for a variety of scientific applications and human activities. Due to the non-linearity of the phenomenon, a complete description of such variable is made infeasible on both the small scale and large spatial extents. Methods relying on Data Assimilation techniques, despite being the state-of-the-art for Numerical Weather Prediction, can not provide the reconstructions with a spatial resolution that can compete with satellite imagery. In this work we propose a framework based on Variational Data Assimilation and Deep Learning concepts. This framework is applied to recover rich-in-time, high-resolution information on sea surface wind speed. We design our experiments using synthetic wind data and different sampling schemes for high-resolution and low-resolution versions of original data to emulate the real-world scenario of spatio-temporally heterogeneous observations. Extensive numerical experiments are performed to assess systematically the impact of low and high-resolution wind fields and in-situ observations on the model reconstruction performance. We show that in-situ observations with richer temporal resolution represent an added value in terms of the model reconstruction performance. We show how a multi-modal approach, that explicitly informs the model about the heterogeneity of the available observations, can improve the reconstruction task by exploiting the complementary information in spatial and local point-wise data. To conclude, we propose an analysis to test the robustness of the chosen framework against phase delay and amplitude biases in low-resolution data and against interruptions of in-situ observations supply at evaluation time