FN Archimer Export Format PT J TI Equatorial deep jets triggered by a large vertical scale variability within the western boundary layer BT AF D'ORGEVILLE, Marc HUA, Bach-Lien SASAKI, H AS 1:1;2:3;3:2; FF 1:;2:PDG-DOP-DCB-OPS-LPO;3:; C1 CNRS, UBO, IFREMER, Lab Phys Oceans, F-29280 Plouzane, France. Japan Agcy Marine Earth Sci & Technol, Yokohama Inst Earth Sci, Earth Simulator Ctr, Kanazawa Ku, Yokohama, Kanagawa 2360001, Japan. IFREMER, Lab Phys Oceans, F-29280 Plouzane, France. C2 UBO, FRANCE JAMSTEC, JAPAN IFREMER, FRANCE SI BREST SE PDG-DOP-DCB-OPS-LPO IN WOS Ifremer jusqu'en 2018 copubli-france copubli-univ-france copubli-int-hors-europe IF 1.565 TC 32 UR https://archimer.ifremer.fr/doc/2007/publication-2534.pdf LA English DT Article AB The response of the deep equatorial ocean to an oscillatory baroclinic western boundary current is investigated in a continuously stratified primitive equation model. The symmetry of the current about the equator is such that mixed Rossby-gravity (MRG) waves are excited in the western part of the equatorial ocean. Depending on the forcing frequency, short to long scale (when compared to equatorial Rossby radius) monochromatic (MRG) waves are selected. The subsequent MRG wave destabilization generally leads to a much higher vertical mode response than the forced MRG wave mode. In a channel, short MRG waves are destabilized by shear instability (Hua et al., 2007). In a basin, the destabilization occurs in the vicinity of the western boundary and leads to the formation of finite amplitude, nonlinear jets in the entire equatorial basin. The space and time pattern of the jets correspond to low-frequency oscillating equatorial basin-modes, the period of which is set by the dominant vertical mode of the response. The vertical scale of the jets is a function mainly of the forcing period and is independent of the forcing vertical mode, as long as the excited MRG waves are in a sufficiently short regime to be unstable. As a result, an oscillatory western boundary current leads to a permanent equatorial zonal circulation, unlike a steady western boundary current. But most importantly, MRG wave destabilization appears to be a plausible formation mechanism for the observed Equatorial Deep Jets. The spatial and dynamical characteristics of the zonal circulation achieved with a 60-day forcing period are indeed compatible with the observations in the Atlantic Ocean. PY 2007 SO Journal of Marine Research SN 0022-2402 PU Yale University VL 65 IS 1 UT 000245520300001 BP 1 EP 25 DI 10.1357/002224007780388720 ID 2534 ER EF