Observed eddy dissipation in the Agulhas Current

被引：18

作者：

Braby, Laura ^{[1
]}

Backeberg, Bjorn C. ^{[2
,3
,4
]}

Ansorge, Isabelle ^{[5
]}

Roberts, Michael J. ^{[6
,7
]}

Krug, Marjolaine ^{[1
,3
,8
]}

Reason, Chris J. C. ^{[1
]}

机构：

[1] Univ Cape Town, Dept Oceanog, Cape Town, South Africa

[2] CSIR, Coastal Syst Res Grp, Nat Resources & Environm, Stellenbosch, South Africa

[3] Univ Cape Town, Dept Oceanog, Nansen Tutu Ctr Marine Environm Res, Cape Town, South Africa

[4] Nansen Environm & Remote Sensing Ctr, Bergen, Norway

[5] Univ Cape Town, Marine Res Inst, Dept Oceanog, Cape Town, South Africa

[6] Nelson Mandela Metropolitan Univ, Ocean Sci & Marine Food Secur, Port Elizabeth, South Africa

[7] Natl Oceanog Ctr, European Way, Southampton, Hants, England

[8] CSIR, Earth Observat Res Grp, Nat Resources & Environm, Cape Town, South Africa

来源：

GEOPHYSICAL RESEARCH LETTERS | 2016年 / 43卷 / 15期

基金：

新加坡国家研究基金会;

关键词：

source region eddies; Agulhas Current; GENERATION; TRANSPORT; LEAKAGE; EDDIES; ENERGY;

D O I：

10.1002/2016GL069480

中图分类号：

P [天文学、地球科学];

学科分类号：

070403 [天体物理学];

摘要：

Analyzing eddy characteristics from a global data set of automatically tracked eddies for the Agulhas Current in combination with surface drifters as well as geostrophic currents from satellite altimeters, it is shown that eddies from the Mozambique Channel and south of Madagascar dissipate as they approach the Agulhas Current. By tracking the offshore position of the current core and its velocity at 30 degrees S in relation to eddies, it is demonstrated that eddy dissipation occurs through a transfer of momentum, where anticyclones consistently induce positive velocity anomalies, and cyclones reduce the velocities and cause offshore meanders. Composite analyses of the anticyclonic (cyclonic) eddy-current interaction events demonstrate that the positive (negative) velocity anomalies propagate downstream in the Agulhas Current at 44km/d (23km/d). Many models are unable to represent these eddy dissipation processes, affecting our understanding of the Agulhas Current.

引用

页码：8143 / 8150

页数：8

共 32 条

[1]

A connection between the South Equatorial Current north of Madagascar and Mozambique Channel Eddies [J].