Blending drifters and altimetric data to estimate surface currents: Application in the Levantine Mediterranean and objective validation with different data types. (October 2021)

• Record Type: Journal Article
• Authors: Baaklini, Georges; Issa, Leila; Fakhri, Milad; Brajard, Julien; Fifani, Gina; Menna, Milena; Taupier-Letage, Isabelle; Bosse, Anthony; Mortier, Laurent
• Is Part Of: Ocean modelling. Volume 166(2021)
• Publication Date: 2021-10
• Subjects: Altimetry -- Lagrangian data -- Data assimilation -- Drifters -- Surface velocity field -- Levantine Mediterranean; Oceanography -- Periodicals; Océanographie -- Périodiques; Oceanography; Periodicals; 551.46
• DOI: 10.1016/j.ocemod.2021.101850
• Languages: English
• ISSNs: 1463-5003

Abstract

Abstract: An improved estimation of the surface currents in the Levantine Basin of the Mediterranean sea is crucial for a wide range of applications, including pollutants transport and nutrients distribution. This estimation remains challenging due to the scarcity or shortcomings of various data types used for this purpose. In this paper, we present an objective validation of a variational assimilation algorithm that blends geostrophic velocities derived from altimetry, wind-induced velocities, and drifter positions, to continuously obtain velocity corrections. The assessment of the validation impact was based on available independent in-situ data (current meters, gliders, and independent drifters) and satellite ocean color images. In all cases, the improvement was shown either qualitatively (position of the eddies) or quantitatively. Highlights: We validate an assimilation algorithm blending drifters and altimetry. The algorithm is extensively applied in the Levantine Mediterranean. The validation is done with independent current meters, gliders and Chl-a images. Significant improvement is shown qualitatively and quantitatively.