Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage
Due to the high nonlinearity, the accurate prediction of the Antarctic circumpolar current (ACC) transport is still challenging. Using the eddy-permitting regional ocean modeling system and the conditional nonlinear optimal perturbation approach, the sudden shift in the ACC transport through Drake P...
Published in: | Journal of Geophysical Research: Oceans |
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ftchinacasciocas:oai:ir.qdio.ac.cn:337002/177685 2023-05-15T13:50:10+02:00 Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage Zhou, Li Wang, Qiang Mu, Mu Zhang, Kun 2021-12-01 http://ir.qdio.ac.cn/handle/337002/177685 https://doi.org/10.1029/2021JC017899 英语 eng AMER GEOPHYSICAL UNION JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS http://ir.qdio.ac.cn/handle/337002/177685 doi:10.1029/2021JC017899 Antarctic Circumpolar Current optimal precursors short-range prediction baroclinic instability CNOP Oceanography SOUTHERN-OCEAN KUROSHIO EXTENSION VOLUME TRANSPORT VARIABILITY CIRCULATION SEA ADJOINT FLUCTUATIONS PERTURBATION TRANSITION 期刊论文 2021 ftchinacasciocas https://doi.org/10.1029/2021JC017899 2022-06-27T05:46:39Z Due to the high nonlinearity, the accurate prediction of the Antarctic circumpolar current (ACC) transport is still challenging. Using the eddy-permitting regional ocean modeling system and the conditional nonlinear optimal perturbation approach, the sudden shift in the ACC transport through Drake Passage (DP) is investigated by exploring its optimal precursor (OPR). Here, the sudden shift in the ACC transport is defined as a fluctuation exceeding double STD (similar to 16 Sv; 1 Sv = 10(6) m(3) s(-1)) within 30 days. The results indicate that the OPRs for all three cases exhibit specific structures in the middle DP (58 degrees-62 degrees S, 72 degrees-64 degrees W) at the depth of 1,000-3,000 m, implying that the ACC transport is most sensitive to the initial perturbations there. The OPRs' evolutions show similar features: the OPR for each case triggers an eddy-like dipole perturbation with a northern cyclone and a southern anticyclone, leading to a sudden reduction in the ACC transport of similar to 40 Sv. It is verified that the density components in the OPRs determine such evolution processes. Furthermore, baroclinic instability is diagnosed to play a dominant role in the development of OPRs by analyzing the perturbed kinetic energy budget. This study suggests that the deep-layer density perturbations in the Southern Ocean should be carefully monitored when considering the short-range prediction of the ACC transport. Report Antarc* Antarctic Drake Passage Southern Ocean Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR Antarctic Southern Ocean The Antarctic Drake Passage Journal of Geophysical Research: Oceans 126 12 |
institution |
Open Polar |
collection |
Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR |
op_collection_id |
ftchinacasciocas |
language |
English |
topic |
Antarctic Circumpolar Current optimal precursors short-range prediction baroclinic instability CNOP Oceanography SOUTHERN-OCEAN KUROSHIO EXTENSION VOLUME TRANSPORT VARIABILITY CIRCULATION SEA ADJOINT FLUCTUATIONS PERTURBATION TRANSITION |
spellingShingle |
Antarctic Circumpolar Current optimal precursors short-range prediction baroclinic instability CNOP Oceanography SOUTHERN-OCEAN KUROSHIO EXTENSION VOLUME TRANSPORT VARIABILITY CIRCULATION SEA ADJOINT FLUCTUATIONS PERTURBATION TRANSITION Zhou, Li Wang, Qiang Mu, Mu Zhang, Kun Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage |
topic_facet |
Antarctic Circumpolar Current optimal precursors short-range prediction baroclinic instability CNOP Oceanography SOUTHERN-OCEAN KUROSHIO EXTENSION VOLUME TRANSPORT VARIABILITY CIRCULATION SEA ADJOINT FLUCTUATIONS PERTURBATION TRANSITION |
description |
Due to the high nonlinearity, the accurate prediction of the Antarctic circumpolar current (ACC) transport is still challenging. Using the eddy-permitting regional ocean modeling system and the conditional nonlinear optimal perturbation approach, the sudden shift in the ACC transport through Drake Passage (DP) is investigated by exploring its optimal precursor (OPR). Here, the sudden shift in the ACC transport is defined as a fluctuation exceeding double STD (similar to 16 Sv; 1 Sv = 10(6) m(3) s(-1)) within 30 days. The results indicate that the OPRs for all three cases exhibit specific structures in the middle DP (58 degrees-62 degrees S, 72 degrees-64 degrees W) at the depth of 1,000-3,000 m, implying that the ACC transport is most sensitive to the initial perturbations there. The OPRs' evolutions show similar features: the OPR for each case triggers an eddy-like dipole perturbation with a northern cyclone and a southern anticyclone, leading to a sudden reduction in the ACC transport of similar to 40 Sv. It is verified that the density components in the OPRs determine such evolution processes. Furthermore, baroclinic instability is diagnosed to play a dominant role in the development of OPRs by analyzing the perturbed kinetic energy budget. This study suggests that the deep-layer density perturbations in the Southern Ocean should be carefully monitored when considering the short-range prediction of the ACC transport. |
format |
Report |
author |
Zhou, Li Wang, Qiang Mu, Mu Zhang, Kun |
author_facet |
Zhou, Li Wang, Qiang Mu, Mu Zhang, Kun |
author_sort |
Zhou, Li |
title |
Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage |
title_short |
Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage |
title_full |
Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage |
title_fullStr |
Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage |
title_full_unstemmed |
Optimal Precursors Triggering Sudden Shifts in the Antarctic Circumpolar Current Transport Through Drake Passage |
title_sort |
optimal precursors triggering sudden shifts in the antarctic circumpolar current transport through drake passage |
publisher |
AMER GEOPHYSICAL UNION |
publishDate |
2021 |
url |
http://ir.qdio.ac.cn/handle/337002/177685 https://doi.org/10.1029/2021JC017899 |
geographic |
Antarctic Southern Ocean The Antarctic Drake Passage |
geographic_facet |
Antarctic Southern Ocean The Antarctic Drake Passage |
genre |
Antarc* Antarctic Drake Passage Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Southern Ocean |
op_relation |
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS http://ir.qdio.ac.cn/handle/337002/177685 doi:10.1029/2021JC017899 |
op_doi |
https://doi.org/10.1029/2021JC017899 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
126 |
container_issue |
12 |
_version_ |
1766253136386719744 |