Variability and trends in Southern Ocean eddy activity in 1/12° ocean model simulations

• Published in: Geophysical Research Letters
• Main Authors: Patara, Lavinia, Böning, Claus W., Biastoch, Arne
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU (American Geophysical Union) 2016
• Subjects: Antarctic; Indian; Pacific; Southern Ocean; The Antarctic; Antarc*
• Online Access: https://oceanrep.geomar.de/id/eprint/32342/; https://oceanrep.geomar.de/id/eprint/32342/1/grl54386.pdf; https://oceanrep.geomar.de/id/eprint/32342/2/grl54386-sup-0001-2016GL069026-SI.pdf; https://oceanrep.geomar.de/id/eprint/32342/3/grl54386-sup-0001-gr54386-sup-0001-2016GL069026-ms01.m4v; https://oceanrep.geomar.de/id/eprint/32342/4/grl54386-sup-0002-gr54386-sup-0001-2016GL069026-ms02.m4v; https://doi.org/10.1002/2016GL069026

The response of eddy kinetic energy (EKE) to the strengthening of Southern Hemisphere winds occurring since the 1950s is investigated with a global ocean model having a resolution of 1/12° in the Antarctic Circumpolar Current domain. The simulations expose regional differences in the relative importance of stochastic and wind-related contributions to inter-annual EKE changes. In the Pacific and Indian sectors the model captures the EKE variability observed since 1993 and confirms previous hypotheses of a lagged response to regional wind stress anomalies. Here, the multi-decadal trend in wind stress is reflected in an increase in EKE typically exceeding 5 cm2 sec-2 decade-1. In the western Atlantic EKE variability is mostly stochastic, is weakly correlated with wind fluctuations, and its multi-decadal trends are close to zero. The non-uniform distribution of wind-related changes in the eddy activity could affect the regional patterns of ocean circulation and biogeochemical responses to future climate change.