661 / 2024-09-18 20:45:35
Quadruple Enhancement of Surface Chlorophyll Growth by Submesocale Fronts of Oceanic Eddies
Oceanic submesoscale processes,submesoscale fronts,ocean biogeochemistry,chlorophyll growth
Session 46 - Oceanic Mesoscale and Submesoscale Processes: Characteristics, Dynamics & Parameterizations
Abstract Accepted
Hanrui Liu / Ocean University of China;Academy of the Future Ocean;Frontiers Science Center for Deep Ocean Multispheres and Earth System (FDOMES) and Key Laboratory of Physical Oceanograph
Bo Qiu / University of Hawaii at Manoa;Department of Oceanography
Hailin Wang / Ocean University of China;Academy of the Future Ocean;Frontiers Science Center for Deep Ocean Multispheres and Earth System (FDOMES) and Key Laboratory of Physical Oceanography
Zhengguang Zhang / Ocean University of China;Laoshan Laboratory;Academy of the Future Ocean;Frontiers Science Center for Deep Ocean Multispheres and Earth System (FDOMES) and Key Laboratory of Physical Oceanography
Submesoscale fronts have been recognized as important contributors to nutrient supply for primary production in the euphotic layer. Their small spatio-temporal scale (100-101 km, 100-101 days) has hindered the understanding of their spatial structures, temporal evolution and biogeochemical impact. Here, by combining the global multi-platformed observations, we find that the submesoscale fronts around oceanic eddies are featured by an along-front enhancement of ageostrophic kinetic energy. Stronger fronts increase fourfold the surface chlorophyll growth rate on the warm side of the fronts, where the upwelling branch of a vertical secondary circulation emerges. The temporal evolution of submesoscale fronts of oceanic eddies is characterized by a frontal intensity peak with a lifecycle about 10 days. The frontal processes induce biogeochemical impact on a larger scale, which exhibits a net enhancement of surface chlorophyll of the corresponding eddies during this lifecycle, and the strongest enhancement of surface chlorophyll emerges when the frontal intensity reaches its maximum.