FN Archimer Export Format
PT J
TI Intra-Annual Rossby Waves Destabilization as a Potential Driver of Low-Latitude Zonal Jets: Barotropic Dynamics
BT 
AF Delpech, Audrey
   Ménesguen, Claire
   Morel, Yves
   Thomas, Leif N
   Marin, Frederic
   Cravatte, Sophie
   Le Gentil, Sylvie
AS 1:1;2:2;3:1;4:3;5:1;6:1;7:2;
FF 1:;2:PDG-ODE-LOPS-OH;3:;4:;5:;6:;7:PDG-ODE-LOPS-OH;
C1 LEGOS, Université de Toulouse, CNRS, CNES, IRD, Toulouse, France
   LOPS, Université de Bretagne Occidentale, Ifremer, CNRS, IRD, Brest, France
   Department of Earth System Science, Stanford University, Stanford, California
C2 OBSERV MIDI PYRENEES, FRANCE
   IFREMER, FRANCE
   UNIV STANFORD, USA
SI BREST
SE PDG-ODE-LOPS-OH
UM LOPS
IN WOS Ifremer UMR
   copubli-france
   copubli-int-hors-europe
IF 3.806
TC 4
UR https://archimer.ifremer.fr/doc/00677/78921/81289.pdf
LA English
DT Article
DE ;Ocean circulation;Jets;Rossby waves;Nonlinear dynamics
AB At low latitudes in the ocean, the deep currents are shaped into narrow jets flowing eastward and westward, reversing periodically with latitude between 15°S and 15°N. These jets are present from the thermocline to the bottom. The energy sources and the physical mechanisms responsible for their formation are still debated and poorly understood. This study explores the role of the destabilization of intra-annual equatorial waves in the jets’ formation process, as these waves are known to be an important energy source at low latitudes. The study focuses particularly on the role of barotropic Rossby waves as a first step toward understanding the relevant physical mechanisms. It is shown from a set of idealized numerical simulations and analytical solutions that nonlinear triad interactions (NLTIs) play a crucial role in the transfer of energy toward jet-like structures (long waves with short meridional wavelengths) that induce a zonal residual mean circulation. The sensitivity of the instability emergence and the scale selection of the jet-like secondary wave to the forced primary wave are analyzed. For realistic amplitudes around 5–20 cm s−1, the primary waves that produce the most realistic jet-like structures are zonally propagating intra-annual waves with periods between 60 and 130 days and wavelengths between 200 and 300 km. The NLTI mechanism is a first step toward the generation of a permanent jet-structured circulation and is discussed in the context of turbulent cascade theories. 
PY 2021
PD JAN
SO Journal Of Physical Oceanography
SN 0022-3670
PU American Meteorological Society
VL 51
IS 2
UT 000646377800006
BP 365
EP 384
DI 10.1175/JPO-D-20-0180.1
ID 78921
ER

EF