Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data
<p>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 co...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-04-01
|
| Series: | Ocean Science |
| Online Access: | https://www.ocean-sci.net/15/413/2019/os-15-413-2019.pdf |
| _version_ | 1818060756429570048 |
|---|---|
| author | W. Cui W. Cui W. Wang J. Zhang J. Yang |
| author_facet | W. Cui W. Cui W. Wang J. Zhang J. Yang |
| author_sort | W. Cui |
| collection | DOAJ |
| description | <p>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<span class="inline-formula"><sup>∘</sup></span>) 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.</p> |
| first_indexed | 2024-12-10T13:37:29Z |
| format | Article |
| id | doaj.art-a4718f4d03284b9b932dfa092fc708a7 |
| institution | Directory Open Access Journal |
| issn | 1812-0784 1812-0792 |
| language | English |
| last_indexed | 2024-12-10T13:37:29Z |
| publishDate | 2019-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Ocean Science |
| spelling | doaj.art-a4718f4d03284b9b932dfa092fc708a72022-12-22T01:46:47ZengCopernicus PublicationsOcean Science1812-07841812-07922019-04-011541343010.5194/os-15-413-2019Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter dataW. Cui0W. Cui1W. Wang2J. Zhang3J. Yang4First Institute of Oceanography, Ministry of Natural Resources of China, Qingdao, ChinaPhysical Oceanography Lab, Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao, ChinaPhysical Oceanography Lab, Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao, ChinaFirst Institute of Oceanography, Ministry of Natural Resources of China, Qingdao, ChinaFirst Institute of Oceanography, Ministry of Natural Resources of China, Qingdao, China<p>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<span class="inline-formula"><sup>∘</sup></span>) 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.</p>https://www.ocean-sci.net/15/413/2019/os-15-413-2019.pdf |
| spellingShingle | W. Cui W. Cui W. Wang J. Zhang J. Yang Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data Ocean Science |
| title | 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_short | 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 |
| url | https://www.ocean-sci.net/15/413/2019/os-15-413-2019.pdf |
| work_keys_str_mv | AT wcui multicorestructuresandthesplittingandmergingofeddiesinglobaloceansfromsatellitealtimeterdata AT wcui multicorestructuresandthesplittingandmergingofeddiesinglobaloceansfromsatellitealtimeterdata AT wwang multicorestructuresandthesplittingandmergingofeddiesinglobaloceansfromsatellitealtimeterdata AT jzhang multicorestructuresandthesplittingandmergingofeddiesinglobaloceansfromsatellitealtimeterdata AT jyang multicorestructuresandthesplittingandmergingofeddiesinglobaloceansfromsatellitealtimeterdata |