Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winter
Abstract The Kuroshio, which flows to the south of Japan, typically takes two paths on decadal timescales; the straight path and the large meander path, or the so-called Kuroshio large meander. This phenomenon is characterized by the presence of the cyclonic cold-core eddy located south of Japan, wh...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-03-01
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| Series: | Progress in Earth and Planetary Science |
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| Online Access: | https://doi.org/10.1186/s40645-024-00620-3 |
| _version_ | 1797233173903441920 |
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| author | Yoshi N. Sasaki Ryunosuke Ito |
| author_facet | Yoshi N. Sasaki Ryunosuke Ito |
| author_sort | Yoshi N. Sasaki |
| collection | DOAJ |
| description | Abstract The Kuroshio, which flows to the south of Japan, typically takes two paths on decadal timescales; the straight path and the large meander path, or the so-called Kuroshio large meander. This phenomenon is characterized by the presence of the cyclonic cold-core eddy located south of Japan, which leads to both negative and positive sea surface temperature (SST) anomalies along the southeastern coast of Japan. To clarify the atmospheric response to these SST anomalies in winter, we conducted a control experiment employing a regional atmospheric model with observed SSTs and two sensitivity experiments in which the SST boundary conditions were substituted with those corresponding to the periods of for the Kuroshio large meander and the straight path. The differences in these two sensitivity experiments showed that the surface wind response to the SST anomalies associated with the Kuroshio large meander was not only characterized by wind divergence over the cyclonic cold-core eddy, as reported previously but also wind convergence along the southeastern coast of Japan. Interestingly, this wind anomaly blew into the positive SST anomaly along the east coast of Japan at around 36°N. Similar wind anomalies along the east coast of Japan were observed in a reanalysis product. The results of the model simulation and the reanalysis product showed that during the Kuroshio large meander period, the number of rainy days increased significantly over the warm SST anomaly, while the precipitation and the number of rainy days decreased over the cyclonic cold-core eddy. Moisture budget analysis revealed that the observed decrease in precipitation was attributed to the disparity between the reduced evaporation and the anomalous horizontal moisture convergence in a region where the surface winds were divergent. This moisture convergence was mainly induced by a decrease in specific humidity, implying this change in specific humidity effectively mitigated the variation in precipitation. |
| first_indexed | 2024-04-24T16:11:58Z |
| format | Article |
| id | doaj.art-40a46b11b89949ee99be4d0eef5efe90 |
| institution | Directory Open Access Journal |
| issn | 2197-4284 |
| language | English |
| last_indexed | 2024-04-24T16:11:58Z |
| publishDate | 2024-03-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Progress in Earth and Planetary Science |
| spelling | doaj.art-40a46b11b89949ee99be4d0eef5efe902024-03-31T11:38:21ZengSpringerOpenProgress in Earth and Planetary Science2197-42842024-03-0111111310.1186/s40645-024-00620-3Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winterYoshi N. Sasaki0Ryunosuke Ito1Faculty of Science, Hokkaido UniversityFaculty of Science, Hokkaido UniversityAbstract The Kuroshio, which flows to the south of Japan, typically takes two paths on decadal timescales; the straight path and the large meander path, or the so-called Kuroshio large meander. This phenomenon is characterized by the presence of the cyclonic cold-core eddy located south of Japan, which leads to both negative and positive sea surface temperature (SST) anomalies along the southeastern coast of Japan. To clarify the atmospheric response to these SST anomalies in winter, we conducted a control experiment employing a regional atmospheric model with observed SSTs and two sensitivity experiments in which the SST boundary conditions were substituted with those corresponding to the periods of for the Kuroshio large meander and the straight path. The differences in these two sensitivity experiments showed that the surface wind response to the SST anomalies associated with the Kuroshio large meander was not only characterized by wind divergence over the cyclonic cold-core eddy, as reported previously but also wind convergence along the southeastern coast of Japan. Interestingly, this wind anomaly blew into the positive SST anomaly along the east coast of Japan at around 36°N. Similar wind anomalies along the east coast of Japan were observed in a reanalysis product. The results of the model simulation and the reanalysis product showed that during the Kuroshio large meander period, the number of rainy days increased significantly over the warm SST anomaly, while the precipitation and the number of rainy days decreased over the cyclonic cold-core eddy. Moisture budget analysis revealed that the observed decrease in precipitation was attributed to the disparity between the reduced evaporation and the anomalous horizontal moisture convergence in a region where the surface winds were divergent. This moisture convergence was mainly induced by a decrease in specific humidity, implying this change in specific humidity effectively mitigated the variation in precipitation.https://doi.org/10.1186/s40645-024-00620-3KuroshioLarge meanderAir-sea interactionPrecipitationRegional atmospheric model |
| spellingShingle | Yoshi N. Sasaki Ryunosuke Ito Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winter Progress in Earth and Planetary Science Kuroshio Large meander Air-sea interaction Precipitation Regional atmospheric model |
| title | Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winter |
| title_full | Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winter |
| title_fullStr | Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winter |
| title_full_unstemmed | Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winter |
| title_short | Impact of the Kuroshio large meander on local atmospheric circulation and precipitation in winter |
| title_sort | impact of the kuroshio large meander on local atmospheric circulation and precipitation in winter |
| topic | Kuroshio Large meander Air-sea interaction Precipitation Regional atmospheric model |
| url | https://doi.org/10.1186/s40645-024-00620-3 |
| work_keys_str_mv | AT yoshinsasaki impactofthekuroshiolargemeanderonlocalatmosphericcirculationandprecipitationinwinter AT ryunosukeito impactofthekuroshiolargemeanderonlocalatmosphericcirculationandprecipitationinwinter |