Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data
This study investigated the statistics of eddy splitting and merging in the global oceans based on 23 years of altimetry data. Multicore structures were identified using an improved geometric closed-contour algorithm of sea surface height. Splitting and merging events were discerned from continuous...
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ftcopernicus:oai:publications.copernicus.org:os70865 2023-05-15T13:55:28+02:00 Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data Cui, Wei Wang, Wei Zhang, Jie Yang, Jungang 2019-04-15 application/pdf https://doi.org/10.5194/os-15-413-2019 https://os.copernicus.org/articles/15/413/2019/ eng eng doi:10.5194/os-15-413-2019 https://os.copernicus.org/articles/15/413/2019/ eISSN: 1812-0792 Text 2019 ftcopernicus https://doi.org/10.5194/os-15-413-2019 2020-07-20T16:22:51Z This study investigated the statistics of eddy splitting and merging in the global oceans based on 23 years of altimetry data. Multicore structures were identified using an improved geometric closed-contour algorithm of sea surface height. Splitting and merging events were discerned from continuous time series maps of sea level anomalies. Multicore structures represent an intermediate stage in the process of eddy evolution, similar to the generation of multiple nuclei in a cell as a preparatory phase for cell division. Generally, splitting or merging events can substantially change (by a factor of 2 or more) the eddy scale, amplitude, and eddy kinetic energy. Specifically, merging (splitting) generally causes an increase (decrease) of eddy properties. Multicore eddies were found to tend to split into two eddies with different intensities. Similarly, eddy merging is not an interaction of two equal-intensity eddies, and it tends to manifest as a strong eddy merging with a weaker one. A hybrid tracking strategy based on the eddy overlap ratio, considering both multicore and single-core eddies, was used to confirm splitting and merging events globally. The census revealed that eddy splitting and merging do not always occur most frequently in eddy-rich regions; e.g., their frequencies of occurrence in the Antarctic Circumpolar Current and western boundary currents were found to be greater than in midlatitude regions (20–35 ∘ ) to the north and south. Eddy splitting and merging are caused primarily by an unstable configuration of multicore structures due to obvious current– or eddy–topography interaction, strong current variation, and eddy–mean flow interaction. Text Antarc* Antarctic Copernicus Publications: E-Journals Antarctic The Antarctic Ocean Science 15 2 413 430 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
This study investigated the statistics of eddy splitting and merging in the global oceans based on 23 years of altimetry data. Multicore structures were identified using an improved geometric closed-contour algorithm of sea surface height. Splitting and merging events were discerned from continuous time series maps of sea level anomalies. Multicore structures represent an intermediate stage in the process of eddy evolution, similar to the generation of multiple nuclei in a cell as a preparatory phase for cell division. Generally, splitting or merging events can substantially change (by a factor of 2 or more) the eddy scale, amplitude, and eddy kinetic energy. Specifically, merging (splitting) generally causes an increase (decrease) of eddy properties. Multicore eddies were found to tend to split into two eddies with different intensities. Similarly, eddy merging is not an interaction of two equal-intensity eddies, and it tends to manifest as a strong eddy merging with a weaker one. A hybrid tracking strategy based on the eddy overlap ratio, considering both multicore and single-core eddies, was used to confirm splitting and merging events globally. The census revealed that eddy splitting and merging do not always occur most frequently in eddy-rich regions; e.g., their frequencies of occurrence in the Antarctic Circumpolar Current and western boundary currents were found to be greater than in midlatitude regions (20–35 ∘ ) to the north and south. Eddy splitting and merging are caused primarily by an unstable configuration of multicore structures due to obvious current– or eddy–topography interaction, strong current variation, and eddy–mean flow interaction. |
format |
Text |
author |
Cui, Wei Wang, Wei Zhang, Jie Yang, Jungang |
spellingShingle |
Cui, Wei Wang, Wei Zhang, Jie Yang, Jungang Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data |
author_facet |
Cui, Wei Wang, Wei Zhang, Jie Yang, Jungang |
author_sort |
Cui, Wei |
title |
Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data |
title_short |
Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data |
title_full |
Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data |
title_fullStr |
Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data |
title_full_unstemmed |
Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data |
title_sort |
multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data |
publishDate |
2019 |
url |
https://doi.org/10.5194/os-15-413-2019 https://os.copernicus.org/articles/15/413/2019/ |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
eISSN: 1812-0792 |
op_relation |
doi:10.5194/os-15-413-2019 https://os.copernicus.org/articles/15/413/2019/ |
op_doi |
https://doi.org/10.5194/os-15-413-2019 |
container_title |
Ocean Science |
container_volume |
15 |
container_issue |
2 |
container_start_page |
413 |
op_container_end_page |
430 |
_version_ |
1766262115424796672 |