Publication Date:
2022-05-25
Description:
Author Posting. © American Meteorological Society, 2017. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 47 (2017): 633-647, doi:10.1175/JPO-D-16-0089.1.
Description:
Interannual variability in the volumetric water mass distribution within the North Atlantic Subtropical Gyre is described in relation to variability in the Atlantic meridional overturning circulation. The relative roles of diabatic and adiabatic processes in the volume and heat budgets of the subtropical gyre are investigated by projecting data into temperature coordinates as volumes of water using an Argo-based climatology and an ocean state estimate (ECCO version 4). This highlights that variations in the subtropical gyre volume budget are predominantly set by transport divergence in the gyre. A strong correlation between the volume anomaly due to transport divergence and the variability of both thermocline depth and Ekman pumping over the gyre suggests that wind-driven heave drives transport anomalies at the gyre boundaries. This wind-driven heaving contributes significantly to variations in the heat content of the gyre, as do anomalies in the air–sea fluxes. The analysis presented suggests that wind forcing plays an important role in driving interannual variability in the Atlantic meridional overturning circulation and that this variability can be unraveled from spatially distributed hydrographic observations using the framework presented here.
Description:
DGE was supported by a Natural
Environment Research Council studentship award
at the University of Southampton. JMT’s contribution
was supported by the U.S. National Science Foundation
(Grant OCE-1332667). GF’s contribution was
supported by the U.S. National Science Foundation
through Grant OCE-0961713 and by the U.S. National
Oceanic and Atmospheric Administration through
Grant NA10OAR4310135. The contributions of JDZ
and AJGN were supported by the NERC Grant ‘‘Climate
scale analysis of air and water masses’’ (NE/
K012932/1). ACNG gratefully acknowledges support
from the Leverhulme Trust, the Royal Society, and the
Wolfson Foundation. LY was supported by NASA
Ocean Vector Wind Science Team (OVWST) activities
under Grant NNA10AO86G.
Keywords:
North Atlantic Ocean
;
Atmosphere-ocean interaction
;
Ekman pumping/transport
;
Ocean circulation
;
Water masses
;
Inverse methods
Repository Name:
Woods Hole Open Access Server
Type:
Article
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