BUSCADOR RECOLECTA

Digital.CSIC. Repositorio Institucional del CSIC

oai:digital.csic.es:10261/335521

This study is based upon work from the CSIC Interdisciplinary Thematic Platform Teledeteccion (PTI-TELEDETECT) members.-- 12 pages, 4 figures, supporting information https://doi.org/10.1029/2023GL103688.-- Data Availability Statement: Absolute geostrophic velocity data are available on the CMEMS web platform https://data.marine.copernicus.eu/products, https://doi.org/10.48670/moi-00141. PHYSAT-Med data are referenced at Navarro et al., 2017 and are available at https://nimbus.imedea.uib-csic.es/index.php/s/6w6YzWBpTmWD8BW. The code to compute the particle trajectories and the Finite-Time Lagrangian diagnostics are available at https://zenodo.org/record/7705122, https://doi.org/10.5281/zenodo.7705122 (Hernandez-Carrasco, 2023) with Creative Commons Attribution 4.0 International licence. Figures are plotted using Matlab v2021 software available under licence at https://es.mathworks.com/academia/tah-portal/uib-31521075.html, Diatoms are among the most efficient autotrophic organisms for oceanic primary production and carbon sequestration. Yet, the spatial distributions of these planktonic organisms remain puzzling and the underlying physical processes poorly known, especially in oligotrophic open waters. Here we investigate what dynamical conditions are conducive to episodic diatom blooms in oceanic deserts based on Lagrangian diagnosis and satellite-derived phytoplankton functional types and currents. The coherence of the flow is diagnosed in space and time simultaneously through the Lagrangian coherence rate (LCR) to identify which dynamical structures favor diatom growth. Observations evidence that flow structures with high LCR (40 days or longer) in areas with elevated eddy kinetic energy and vorticity sustain high diatom concentrations in the sunlit layers. Our findings show that the integration of Eulerian kinematic variables into a Lagrangian frame reveals new dynamical aspects of geophysical turbulence and unveil their biological impacts, IH-C acknowledges financial support from the project TRITOP (Grant UIB2021-PD06) funded by University of the Balearic Islands and by FEDER(EU). AO thanks financial support from Projects LAMARCA (PID2021-123352OB-C31) funded by MICIN/AEI/10.13039/501100011033/FEDER, UE and Tech2Coast (TED2021-130949B-I00) funded by MCIN/AEI/10.13039/501100011033 and BY EU ’NextGenerationEU/PRTR’. This work has been partially done in the framework of the AEI accreditation “Maria de Maeztu Centre of Excellence” given to IMEDEA (CSIC-UIB) (CEX2021-001198). AB acknowledges support from the National Science Foundation (Grant OCE-1658174), With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), Peer reviewed