Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysis
<p>The propagation of equatorial waves is essential for the onset of Atlantic Niño, but diagnosing waves with ocean reanalysis or in situ data remains a challenge. This study uses an ocean reanalysis to diagnose the wave energy transfer route during the 2019 event. The climatological values an...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-12-01
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| Series: | Ocean Science |
| Online Access: | https://os.copernicus.org/articles/19/1705/2023/os-19-1705-2023.pdf |
| _version_ | 1797404128890060800 |
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| author | Q. Song Q. Song H. Aiki |
| author_facet | Q. Song Q. Song H. Aiki |
| author_sort | Q. Song |
| collection | DOAJ |
| description | <p>The propagation of equatorial waves is essential for the onset of Atlantic Niño, but diagnosing waves with ocean reanalysis or in situ data remains a challenge. This study uses an ocean reanalysis to diagnose the wave energy transfer route during the 2019 event. The climatological values and the anomaly in 2019 at each grid point are decomposed into the first four baroclinic modes based on their local density profiles. The decomposed geopotential can well reproduce the displacement of the thermocline during the event. Wave energy flux is calculated by means of a group-velocity-based scheme. In addition to detecting wind-forced Kelvin waves and reflected Rossby waves, the wave energy flux reveals another possible energy transfer route along the western boundary, where some off-equatorial wave energy can excite coastally trapped Kelvin waves and transfer back to the equatorial Atlantic. Five transects are selected, across which the passing wave energy fluxes in 2019 are integrated. The results suggest that the Kelvin waves in the third and fourth mode are locally forced, while the wave energy in the second mode is more likely from the off-equatorial region. Therefore, in the autumn of 2019, the second-mode Kelvin waves can deepen the thermocline ahead of other modes from September, serving to precondition the Niño event.</p> |
| first_indexed | 2024-03-09T02:50:30Z |
| format | Article |
| id | doaj.art-949a93b119e44ea9b78d6126e96b09a7 |
| institution | Directory Open Access Journal |
| issn | 1812-0784 1812-0792 |
| language | English |
| last_indexed | 2024-03-09T02:50:30Z |
| publishDate | 2023-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Ocean Science |
| spelling | doaj.art-949a93b119e44ea9b78d6126e96b09a72023-12-05T11:16:16ZengCopernicus PublicationsOcean Science1812-07841812-07922023-12-01191705171710.5194/os-19-1705-2023Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysisQ. Song0Q. Song1H. Aiki2Key Laboratory of Marine Hazards Forecasting, Ministry of Natural Resources, Hohai University, Nanjing, ChinaCollege of Oceanography, Hohai University, Nanjing, ChinaInstitute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan<p>The propagation of equatorial waves is essential for the onset of Atlantic Niño, but diagnosing waves with ocean reanalysis or in situ data remains a challenge. This study uses an ocean reanalysis to diagnose the wave energy transfer route during the 2019 event. The climatological values and the anomaly in 2019 at each grid point are decomposed into the first four baroclinic modes based on their local density profiles. The decomposed geopotential can well reproduce the displacement of the thermocline during the event. Wave energy flux is calculated by means of a group-velocity-based scheme. In addition to detecting wind-forced Kelvin waves and reflected Rossby waves, the wave energy flux reveals another possible energy transfer route along the western boundary, where some off-equatorial wave energy can excite coastally trapped Kelvin waves and transfer back to the equatorial Atlantic. Five transects are selected, across which the passing wave energy fluxes in 2019 are integrated. The results suggest that the Kelvin waves in the third and fourth mode are locally forced, while the wave energy in the second mode is more likely from the off-equatorial region. Therefore, in the autumn of 2019, the second-mode Kelvin waves can deepen the thermocline ahead of other modes from September, serving to precondition the Niño event.</p>https://os.copernicus.org/articles/19/1705/2023/os-19-1705-2023.pdf |
| spellingShingle | Q. Song Q. Song H. Aiki Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysis Ocean Science |
| title | Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysis |
| title_full | Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysis |
| title_fullStr | Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysis |
| title_full_unstemmed | Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysis |
| title_short | Equatorial wave diagnosis for the Atlantic Niño in 2019 with an ocean reanalysis |
| title_sort | equatorial wave diagnosis for the atlantic nino in 2019 with an ocean reanalysis |
| url | https://os.copernicus.org/articles/19/1705/2023/os-19-1705-2023.pdf |
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