FN Archimer Export Format
PT J
TI Agulhas Leakage Predominantly Responds to the Southern Hemisphere Westerlies
BT 
AF DURGADOO, Jonathan V.
   LOVEDAY, Benjamin R.
   REASON, Chris J. C.
   PENVEN, Pierrick
   BIASTOCH, Arne
AS 1:1;2:2;3:2;4:3;5:1;
FF 1:;2:;3:;4:;5:;
C1 GEOMAR Helmholtz Ctr Ocean Res Kiel, D-24105 Kiel, Germany.
   Univ Cape Town, Dept Oceanog, ZA-7925 Cape Town, South Africa.
   UBO, IRD, IFREMER, LMI ICEMASA,LPO,UMR 6523,CNRS, Brest, France.
C2 IFM GEOMAR, GERMANY
   UNIV CAPE TOWN, SOUTH AFRICA
   IRD, FRANCE
IF 2.871
TC 91
UR https://archimer.ifremer.fr/doc/00161/27247/25452.pdf
LA English
DT Article
DE ;Boundary currents;Meridional overturning circulation;Wind stress;Mesoscale models;Numerical analysis;modeling
AB The Agulhas Current plays a crucial role in the thermohaline circulation through its leakage into the South Atlantic Ocean. Under both past and present climates, the trade winds and westerlies could have the ability to modulate the amount of Indian-Atlantic inflow. Compelling arguments have been put forward suggesting that trade winds alone have little impact on the magnitude of Agulhas leakage. Here, employing three ocean models for robust analysisa global coarse-resolution, a regional eddy-permitting, and a nested high-resolution eddy-resolving configurationand systematically altering the position and intensity of the westerly wind belt in a series of sensitivity experiments, it is shown that the westerlies, in particular their intensity, control the leakage. Leakage responds proportionally to the intensity of westerlies up to a certain point. Beyond this, through the adjustment of the large-scale circulation, energetic interactions occur between the Agulhas Return Current and the Antarctic Circumpolar Current that result in a state where leakage no longer increases. This adjustment takes place within one or two decades. Contrary to previous assertions, these results further show that an equatorward (poleward) shift in westerlies increases (decreases) leakage. This occurs because of the redistribution of momentum input by the winds. It is concluded that the reported present-day leakage increase could therefore reflect an unadjusted oceanic response mainly to the strengthening westerlies over the last few decades.
PY 2013
PD OCT
SO Journal Of Physical Oceanography
SN 0022-3670
PU Amer Meteorological Soc
VL 43
IS 10
UT 000325534400005
BP 2113
EP 2131
DI 10.1175/JPO-D-13-047.1
ID 27247
ER

EF