Subregional characterization of mesoscale eddies across the Brazil‐Malvinas Confluence

Journal of Geophysical Research: Oceans - Tập 122 Số 4 - Trang 3329-3357 - 2017
Evan Mason1, Ananda Pascual1, Peter Gaube2, Simón Ruíz1, Josep Lluís Pelegrí3, Antoine Delepoulle4
1IMEDEA (CSIC-UIB), Esporles (Illes Balears), Spain
2Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
3Institut de Ciències del Mar (CSIC), Barcelona, Spain
4C.L.S. Space Oceanography Division, Toulouse, France

Tóm tắt

AbstractHorizontal and vertical motions associated with coherent mesoscale structures, including eddies and meanders, are responsible for significant global transports of many properties, including heat and mass. Mesoscale vertical fluxes also influence upper ocean biological productivity by mediating the supply of nutrients into the euphotic layer, with potential impacts on the global carbon cycle. The Brazil‐Malvinas Confluence (BMC) is a western boundary current region in the South Atlantic with intense mesoscale activity. This region has an active role in the genesis and transformation of water masses and thus is a critical component of the Atlantic meridional overturning circulation. The collision between the Malvinas and Brazil Currents over the Patagonian shelf/slope creates an energetic front that translates offshore to form a vigorous eddy field. Recent improvements in gridded altimetric sea level anomaly fields allow us to track BMC mesoscale eddies with high spatial and temporal resolutions using an automated eddy tracker. We characterize the eddies across fourteen 5° × 5° subregions. Eddy‐centric composites of tracers and geostrophic currents diagnosed from a global reanalysis of surface and in situ data reveal substantial subregional heterogeneity. The in situ data are also used to compute the evolving quasi‐geostrophic vertical velocity (QG‐ω) associated with each instantaneous eddy instance. The QG‐ω eddy composites have the expected dipole patterns of alternating upwelling/downwelling, however, the magnitude and sign of azimuthally averaged vertical velocity varies among subregions. Maximum eddy values are found near fronts and sharp topographic gradients. In comparison with regional eddy composites, subregional composites provide refined information about mesoscale eddy heterogeneity.

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Tài liệu tham khảo

10.1002/rog.20022

10.1016/S0924-7963(01)00062-8

10.1029/2011JC007367

10.1002/2016JC011889

AVISO(2015) SSALTO/DUACS User Handbook: (M)SLA and (M)ADT Near‐Real Time and Delayed Time Products CLS 4.4th ed. sALP‐MU‐P‐EA‐21065‐CLS Toulouse France.

10.5194/os-12-1003-2016

10.1016/j.ocemod.2009.04.004

10.1016/S0967-0637(99)00075-8

10.1002/jgrc.20345

10.1016/j.rse.2005.09.018

10.1175/1520-0485(1995)025<0902:AEASVU>2.0.CO;2

10.1002/2014GL061770

10.1016/j.pocean.2008.10.013

10.1029/2011JC007134

10.1029/2007GL030812

10.1016/j.pocean.2011.01.002

10.1126/science.1208897

10.1002/2013JC009498

10.1021/es1012752

10.1016/j.dsr.2010.07.008

10.1016/j.ocemod.2009.03.007

10.1038/ncomms4294

10.1029/2000JC900063

10.1002/2015JC011371

10.1146/annurev.fluid.40.111406.102139

10.1038/ngeo1863

10.1002/2015JC011047

10.1175/JPO2991.1

10.1029/2009JC005349

10.1016/0967-0637(93)90118-M

10.1016/0198-0149(89)90145-3

10.1016/j.dsr2.2010.10.063

10.1002/2013JC009027

10.1002/2014JC010111

10.1175/JPO-D-14-0032.1

10.1016/0198-0149(89)90042-3

10.1002/2014JC010113

10.1016/j.jmarsys.2003.11.022

10.5194/os-8-845-2012

10.1038/ncomms12811

10.1016/j.dsr2.2013.10.015

10.1016/j.dsr.2012.08.005

10.1002/qj.49710443903

10.1016/B978-0-12-391851-2.00013-1

10.1175/1520-0426(2003)20<772:IOMEFA>2.0.CO;2

10.1175/2009JPO4174.1

10.1029/2004RG000166

10.1175/1520-0426(2003)020<0889:CWMGFW>2.0.CO;2

10.1029/2010JC006285

10.1002/JGRC.20210

10.1175/JTECH-D-14-00019.1

10.1029/93JC01602

10.5194/os-6-983-2010

10.1029/1998JC900131

10.1146/annurev-marine-010814-015606

10.1080/0309192031000108698

10.1175/JPO-D-13-0225.1

10.1016/j.dsr2.2012.04.012

10.1175/2009JTECHO725.1

10.1016/0967-0637(95)00021-W

10.1175/1520-0485(2004)034<2274:AQAOAM>2.0.CO;2

10.1029/2005GL024633

10.1002/2014GL062569

10.1016/0079-6611(91)90006-8

10.1016/j.dsr.2012.10.008

10.5194/os-11-629-2015

10.1002/jgrc.20170

10.1175/1520-0485(1992)022<0609:VAVCAA>2.0.CO;2

Preisendorfer R. W., 1988, Principal Component Analysis in Meteorology and Oceanography, 444

10.5194/os-12-1067-2016

Reynolds R. W.(2009) What's New in Version 2. OISST Webpage. [Available athttp://www.ncdc.noaa.gov/sites/default/files/attachments/Reynolds2009_oisst_daily_v02r00_version2-features.pdf.]

10.1175/2007JCLI1824.1

10.1175/2008JPO3881.1

10.1029/2007GL032827

10.1175/2007JCLI1702.1

10.1175/JPO-D-13-0161.1

10.1175/1520-0485(1995)025<0329:BCDFAS>2.0.CO;2

10.1016/j.dsr.2009.08.008

10.1016/j.dsr.2012.07.005

10.1029/2003JC002127

10.1126/science.277.5334.1956

10.1175/JPO-D-15-0251.1

10.1029/1999JC900139

10.1016/0198-0149(90)90083-8

10.1002/2015JC010769

10.1175/JCLI3485.1

10.1029/2011GL048401

10.1029/2010JC006574

10.1002/2015GL063105

10.1175/1520-0485(1996)026<0684:CITASA>2.0.CO;2

10.1029/2008JC004841

10.1017/CBO9780511612336

10.1002/2014JC010573

10.1038/ngeo943

10.1002/2015GL063120

10.1126/science.1252418

10.1038/srep24349

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Journal of Geophysical Research: Oceans

Tập 122 Số 4

3329-3357

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