{"title":"南海南越上升流的季节内变率:大气强迫和海洋固有变率的影响","authors":"M. Herrmann, Thai To Duy, C. Estournel","doi":"10.5194/os-19-453-2023","DOIUrl":null,"url":null,"abstract":"Abstract. The South Vietnam upwelling (SVU) develops off the Vietnamese coast (South\nChina Sea, SCS) during the southwest summer monsoon over four main areas: the\nnorthern coastal upwelling (NCU), the southern coastal upwelling (SCU), the\noffshore upwelling (OFU) and the shelf off the Mekong River mouth (MKU). An\nensemble of 10 simulations with perturbed initial conditions were run with\nthe fine-resolution SYMPHONIE model (1 km inshore) to investigate the daily\nto intraseasonal variability of the SVU and the influence of the ocean\nintrinsic variability (OIV) during the strong SVU of summer 2018. The intraseasonal variability is similar for the SCU, MKU and OFU, driven to the\nfirst order by the wind variability. The MKU and SCU are induced by stable ocean\ndynamics (the northeastward then eastward boundary current) and have very\nlittle chaotic variability. The OIV has a stronger influence on OFU. In\nJuly, OFU mainly develops along the northern flank of the eastward jet. The\ninfluence of the OIV is strongest and related to the chaotic variability of the\nmeridional position of the jet. In August, this position is stable and OFU\ndevelops mainly in the area of positive wind curl and cyclonic eddies north\nof the jet. The influence of the OIV, weaker than in July, is related to the\norganization of this mesoscale circulation. The NCU shows a behavior different\nfrom that observed in the other areas. In the heart of summer, a large-scale\ncirculation formed by the eastward jet and eddy dipole is well established\nwith an alongshore current preventing the NCU development. In early and late\nsummer, this circulation is weaker, allowing a mesoscale circulation of\nstrongly chaotic nature to develop in the NCU area. During those periods,\nthe OIV influence on the NCU is very strong and related to the organization of\nthis mesoscale circulation: the NCU is favored (annihilated) by\noffshore-oriented (alongshore) structures.\n","PeriodicalId":19535,"journal":{"name":"Ocean Science","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Intraseasonal variability of the South Vietnam upwelling, South China Sea: influence of atmospheric forcing and ocean intrinsic variability\",\"authors\":\"M. Herrmann, Thai To Duy, C. Estournel\",\"doi\":\"10.5194/os-19-453-2023\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. The South Vietnam upwelling (SVU) develops off the Vietnamese coast (South\\nChina Sea, SCS) during the southwest summer monsoon over four main areas: the\\nnorthern coastal upwelling (NCU), the southern coastal upwelling (SCU), the\\noffshore upwelling (OFU) and the shelf off the Mekong River mouth (MKU). An\\nensemble of 10 simulations with perturbed initial conditions were run with\\nthe fine-resolution SYMPHONIE model (1 km inshore) to investigate the daily\\nto intraseasonal variability of the SVU and the influence of the ocean\\nintrinsic variability (OIV) during the strong SVU of summer 2018. The intraseasonal variability is similar for the SCU, MKU and OFU, driven to the\\nfirst order by the wind variability. The MKU and SCU are induced by stable ocean\\ndynamics (the northeastward then eastward boundary current) and have very\\nlittle chaotic variability. The OIV has a stronger influence on OFU. In\\nJuly, OFU mainly develops along the northern flank of the eastward jet. The\\ninfluence of the OIV is strongest and related to the chaotic variability of the\\nmeridional position of the jet. In August, this position is stable and OFU\\ndevelops mainly in the area of positive wind curl and cyclonic eddies north\\nof the jet. The influence of the OIV, weaker than in July, is related to the\\norganization of this mesoscale circulation. The NCU shows a behavior different\\nfrom that observed in the other areas. In the heart of summer, a large-scale\\ncirculation formed by the eastward jet and eddy dipole is well established\\nwith an alongshore current preventing the NCU development. In early and late\\nsummer, this circulation is weaker, allowing a mesoscale circulation of\\nstrongly chaotic nature to develop in the NCU area. During those periods,\\nthe OIV influence on the NCU is very strong and related to the organization of\\nthis mesoscale circulation: the NCU is favored (annihilated) by\\noffshore-oriented (alongshore) structures.\\n\",\"PeriodicalId\":19535,\"journal\":{\"name\":\"Ocean Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2023-04-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Ocean Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.5194/os-19-453-2023\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"METEOROLOGY & ATMOSPHERIC SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ocean Science","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/os-19-453-2023","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
Intraseasonal variability of the South Vietnam upwelling, South China Sea: influence of atmospheric forcing and ocean intrinsic variability
Abstract. The South Vietnam upwelling (SVU) develops off the Vietnamese coast (South
China Sea, SCS) during the southwest summer monsoon over four main areas: the
northern coastal upwelling (NCU), the southern coastal upwelling (SCU), the
offshore upwelling (OFU) and the shelf off the Mekong River mouth (MKU). An
ensemble of 10 simulations with perturbed initial conditions were run with
the fine-resolution SYMPHONIE model (1 km inshore) to investigate the daily
to intraseasonal variability of the SVU and the influence of the ocean
intrinsic variability (OIV) during the strong SVU of summer 2018. The intraseasonal variability is similar for the SCU, MKU and OFU, driven to the
first order by the wind variability. The MKU and SCU are induced by stable ocean
dynamics (the northeastward then eastward boundary current) and have very
little chaotic variability. The OIV has a stronger influence on OFU. In
July, OFU mainly develops along the northern flank of the eastward jet. The
influence of the OIV is strongest and related to the chaotic variability of the
meridional position of the jet. In August, this position is stable and OFU
develops mainly in the area of positive wind curl and cyclonic eddies north
of the jet. The influence of the OIV, weaker than in July, is related to the
organization of this mesoscale circulation. The NCU shows a behavior different
from that observed in the other areas. In the heart of summer, a large-scale
circulation formed by the eastward jet and eddy dipole is well established
with an alongshore current preventing the NCU development. In early and late
summer, this circulation is weaker, allowing a mesoscale circulation of
strongly chaotic nature to develop in the NCU area. During those periods,
the OIV influence on the NCU is very strong and related to the organization of
this mesoscale circulation: the NCU is favored (annihilated) by
offshore-oriented (alongshore) structures.
期刊介绍:
Ocean Science (OS) is a not-for-profit international open-access scientific journal dedicated to the publication and discussion of research articles, short communications, and review papers on all aspects of ocean science: experimental, theoretical, and laboratory. The primary objective is to publish a very high-quality scientific journal with free Internet-based access for researchers and other interested people throughout the world.
Electronic submission of articles is used to keep publication costs to a minimum. The costs will be covered by a moderate per-page charge paid by the authors. The peer-review process also makes use of the Internet. It includes an 8-week online discussion period with the original submitted manuscript and all comments. If accepted, the final revised paper will be published online.
Ocean Science covers the following fields: ocean physics (i.e. ocean structure, circulation, tides, and internal waves); ocean chemistry; biological oceanography; air–sea interactions; ocean models – physical, chemical, biological, and biochemical; coastal and shelf edge processes; paleooceanography.