Inclination Trend of the Agulhas Return Current Path in Three Decades
The Agulhas Return Current (ARC), as a primary component of the Agulhas system, contributes to water exchange and mass transport between the southern portions of the Indian and Atlantic Ocean basins. In this study, satellite altimeter data and reanalysis datasets, and a new set of criteria for the p...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/15/24/5652 |
| _version_ | 1797379496112816128 |
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| author | Yan Lin Liru Lin Dongxiao Wang Xiao-Yi Yang |
| author_facet | Yan Lin Liru Lin Dongxiao Wang Xiao-Yi Yang |
| author_sort | Yan Lin |
| collection | DOAJ |
| description | The Agulhas Return Current (ARC), as a primary component of the Agulhas system, contributes to water exchange and mass transport between the southern portions of the Indian and Atlantic Ocean basins. In this study, satellite altimeter data and reanalysis datasets, and a new set of criteria for the piecewise definition of the jet axis are used to explore the long-term change of the ARC’s axis position in recent three decades. It is found that the ARC axis exhibits a significant slanting trend with its western part (35–48°E) migrating northward and the eastern part (48–70°E) migrating southward. The meridional movement of the ARC path could be attributed to large-scale wind forcing. The anomalous surface wind stress curl, by Ekman pumping mechanism, leads to positive–negative–positive sea surface height anomalies in the western section and negative–positive–negative anomalies in the eastern section, thus the ARC axis tilts accordingly, in a northwest–southeast direction. Further analysis suggests that this ARC slanting trend is more dependent on the southward shift of the downstream axis and less on the topographic steering upstream. The downstream axis is more likely to interact with the ACC fronts and its migration could dominate the local EKE pattern by changing the background circulation and energy cascade direction. For the headstream west of 35°E, the ARC axis is more subject to topography, thus the EKE change is more dominated by eddy activity processes, including shedding, propagation and merging. This study provides some new insights into the long-term change of ARC and its interaction with the local EKE variability. |
| first_indexed | 2024-03-08T20:24:07Z |
| format | Article |
| id | doaj.art-6aedb6d19aff446c90fff2fa249dde21 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-08T20:24:07Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-6aedb6d19aff446c90fff2fa249dde212023-12-22T14:38:52ZengMDPI AGRemote Sensing2072-42922023-12-011524565210.3390/rs15245652Inclination Trend of the Agulhas Return Current Path in Three DecadesYan Lin0Liru Lin1Dongxiao Wang2Xiao-Yi Yang3State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, ChinaXiamen Ocean Vocational College, Xiamen 361100, ChinaSchool of Marine Sciences, Sun Yat-sen University, Guangzhou 510275, ChinaState Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, ChinaThe Agulhas Return Current (ARC), as a primary component of the Agulhas system, contributes to water exchange and mass transport between the southern portions of the Indian and Atlantic Ocean basins. In this study, satellite altimeter data and reanalysis datasets, and a new set of criteria for the piecewise definition of the jet axis are used to explore the long-term change of the ARC’s axis position in recent three decades. It is found that the ARC axis exhibits a significant slanting trend with its western part (35–48°E) migrating northward and the eastern part (48–70°E) migrating southward. The meridional movement of the ARC path could be attributed to large-scale wind forcing. The anomalous surface wind stress curl, by Ekman pumping mechanism, leads to positive–negative–positive sea surface height anomalies in the western section and negative–positive–negative anomalies in the eastern section, thus the ARC axis tilts accordingly, in a northwest–southeast direction. Further analysis suggests that this ARC slanting trend is more dependent on the southward shift of the downstream axis and less on the topographic steering upstream. The downstream axis is more likely to interact with the ACC fronts and its migration could dominate the local EKE pattern by changing the background circulation and energy cascade direction. For the headstream west of 35°E, the ARC axis is more subject to topography, thus the EKE change is more dominated by eddy activity processes, including shedding, propagation and merging. This study provides some new insights into the long-term change of ARC and its interaction with the local EKE variability.https://www.mdpi.com/2072-4292/15/24/5652Agulhas Return Currentlong-term changewind stress curlsea surface heighteddy kinetic energy |
| spellingShingle | Yan Lin Liru Lin Dongxiao Wang Xiao-Yi Yang Inclination Trend of the Agulhas Return Current Path in Three Decades Remote Sensing Agulhas Return Current long-term change wind stress curl sea surface height eddy kinetic energy |
| title | Inclination Trend of the Agulhas Return Current Path in Three Decades |
| title_full | Inclination Trend of the Agulhas Return Current Path in Three Decades |
| title_fullStr | Inclination Trend of the Agulhas Return Current Path in Three Decades |
| title_full_unstemmed | Inclination Trend of the Agulhas Return Current Path in Three Decades |
| title_short | Inclination Trend of the Agulhas Return Current Path in Three Decades |
| title_sort | inclination trend of the agulhas return current path in three decades |
| topic | Agulhas Return Current long-term change wind stress curl sea surface height eddy kinetic energy |
| url | https://www.mdpi.com/2072-4292/15/24/5652 |
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