FN Archimer Export Format
PT J
TI Can mesoscale eddy kinetic energy sources and sinks be inferred from sea surface height in the Agulhas Current ?
BT 
AF Tedesco, Pauline
   Gula, Jonathan
   Penven, Pierrick
   Menesguen, Claire
   Jamet, Quentin
   Vic, Clement
AS 1:1,2;2:1,3;3:5;4:6;5:4;6:6;
FF 1:;2:;3:;4:PDG-ODE-LOPS-OH;5:;6:PDG-ODE-LOPS-OH;
C1 Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Oceanographie Physique et Spatiale (LOPS), IUEM, 5 6 29280, Brest, France
   Imperial College of London, London, UK
   Institut Universitaire de France (IUF), Paris, France
   Institut des Geosciences de l’Environnement (IGE), Grenoble, France
   Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Oceanographie Physique et Spatiale (LOPS), IUEM, 5 6 29280, Brest, France
   Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Oceanographie Physique et Spatiale (LOPS), IUEM, 5 6 29280, Brest, France
C2 UBO, FRANCE
   IMPERIAL COLL LONDON, UK
   INST UNIV FRANCE, FRANCE
   UNIV GRENOBLE ALPES, FRANCE
   CNRS, FRANCE
   IFREMER, FRANCE
SI BREST
SE PDG-ODE-LOPS-OH
UM LOPS
TC 0
UR https://archimer.ifremer.fr/doc/00783/89477/94974.pdf
LA English
DT Article
AB Western boundaries (WB) have been suggested to be hotspots of mesoscale eddy decay, using an eddy kinetic energy (EKE) flux divergence based on sea surface height (η). The η-based diagnostic requires approximations, including the use of geostrophic velocities. Here, we assess to what extent mesoscale EKE flux divergence can be inferred from η using a numerical simulation of the Agulhas Current. The EKE flux divergence is composed of two terms: the eddy-pressure work (linear component) and the advection of EKE (nonlinear component). Both are mainly positive in the WB region (net EKE sources). However, it is not reliably accounted by both η-based diagnostics. The η-based eddy-pressure work has a net contribution in the WB region of the opposite sign than the true one. Ageostrophic eddy-pressure work dominates the geostrophic one (corresponding to a β-contribution). It is explained by mesoscale eddies’s scale to fall below the scale of ζ/β (ζ: root mean square of normalized relative vorticity for mesoscale eddies; β: latitudinal variations of Coriolis parameter). The advection done by geostrophic EKE flux dominates the EKE flux divergence in the WB region. It results in the EKE flux divergence to be qualitatively estimable using η (up to 54 % of the net EKE source). Our results in the Agulhas Current show a mesoscale eddy dynamics in contrast with the decay's paradigm at western boundaries. Further analysis in other western boundaries are required to complete our understanding of mesoscale eddies dynamics. 
PY 2022
PD JUN
SO ESS Open archive
PU ESSOAR
DI 10.1002/essoar.10511782.1
ID 89477
ER

EF