TY - JOUR
T1 - Investigating the formation of submesoscale structures along mesoscale fronts and estimating kinematic quantities using lagrangian drifters
AU - Lodise, John
AU - Özgökmen, Tamay
AU - Gonçalves, Rafael C.
AU - Iskandarani, Mohamed
AU - Lund, Björn
AU - Horstmann, Jochen
AU - Poulain, Pierre Marie
AU - Klymak, Jody
AU - Ryan, Edward H.
AU - Guigand, Cedric
N1 - Publisher Copyright:
© 2020 by the authors.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/9
Y1 - 2020/9
N2 - Much of the vertical transport near the surface of the ocean, which plays a critical role in the transport of dissolved nutrients and gases, is thought to be associated with ageostrophic submesoscale phenomena. Vertical velocities are challenging not only to model accurately, but also to measure because of how difficult they are to locate in the surface waters of the ocean. Using unique massive drifter releases during the Lagrangian Submesoscale Experiment (LASER) campaign in the Gulf of Mexico and the Coherent Lagrangian Pathways from the Surface Ocean to the Interior (CALYPSO) experiment in the Mediterranean Sea, we investigate the generation of submesoscale structures along two different mesoscale fronts. We use a novel method to project Lagrangian trajectories to Eulerian velocity fields, in order to calculate horizontal velocity gradients at the surface, which are used as a proxy for vertical transport. The velocity reconstruction uses a squared-exponential covariance function, which characterizes velocity correlations in horizontal space and time, and determines the scales of variation using the data itself. SST and towed CTD measurements support the findings revealed by the drifter data. Due to the production of a submesoscale instability eddy in the Gulf of Mexico, convergence magnitudes of up to ∼ 20 times the planetary vorticity, f , are observed, the value of which is almost 3 times larger than that found in the mesoscale dominated Western Mediterranean Sea.
AB - Much of the vertical transport near the surface of the ocean, which plays a critical role in the transport of dissolved nutrients and gases, is thought to be associated with ageostrophic submesoscale phenomena. Vertical velocities are challenging not only to model accurately, but also to measure because of how difficult they are to locate in the surface waters of the ocean. Using unique massive drifter releases during the Lagrangian Submesoscale Experiment (LASER) campaign in the Gulf of Mexico and the Coherent Lagrangian Pathways from the Surface Ocean to the Interior (CALYPSO) experiment in the Mediterranean Sea, we investigate the generation of submesoscale structures along two different mesoscale fronts. We use a novel method to project Lagrangian trajectories to Eulerian velocity fields, in order to calculate horizontal velocity gradients at the surface, which are used as a proxy for vertical transport. The velocity reconstruction uses a squared-exponential covariance function, which characterizes velocity correlations in horizontal space and time, and determines the scales of variation using the data itself. SST and towed CTD measurements support the findings revealed by the drifter data. Due to the production of a submesoscale instability eddy in the Gulf of Mexico, convergence magnitudes of up to ∼ 20 times the planetary vorticity, f , are observed, the value of which is almost 3 times larger than that found in the mesoscale dominated Western Mediterranean Sea.
KW - Kinematics
KW - Lagrangian drifters
KW - Mesoscale/submesoscale interaction
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U2 - 10.3390/fluids5030159
DO - 10.3390/fluids5030159
M3 - Article
AN - SCOPUS:85092610675
VL - 5
JO - Fluids
JF - Fluids
SN - 2311-5521
IS - 3
M1 - A3
ER -