{"title":"长期涡流调节影响波弗特环流中晕线的经向不对称性","authors":"Jinling Lu, Ling Du, Shuhao Tao","doi":"10.5194/os-19-1773-2023","DOIUrl":null,"url":null,"abstract":"Abstract. Against the background of wind-forcing change along with Arctic sea ice retreat, the mesoscale processes undergoing distinct variation in the Beaufort Gyre (BG) region are increasingly important to oceanic transport and energy cascades, and these changes subsequently put oceanic stratification into a new state. Here, the varying number and strength of eddies in the central Canada Basin (CB) and Chukchi–Beaufort continental slope are obtained based on mooring observations (2003–2018), altimetry measurements (1993–2019), and reanalysis data (1980–2020). In this paper, the variability in the BG halocline, representing the adjustment of stratification in the upper layer, is shown in order to analyse how variability occurs under changing mesoscale processes. We find that over almost the last 2 decades the halocline depth has deepened by ∼ 40 m in the south of the central gyre, while that in the north has deepened by ∼ 70 m according to multiple datasets. Surrounding the central gyre, the asymmetry of the halocline, with much steeper and deeper isopycnals over the southern continental slope, reduced after 2014. In the meantime, eddy activities in the upper layer from the southern margin of the BG to the abyssal plain have been enhanced. Moreover, the convergence of the eddy lateral flux has increased as the halocline structures on either side, which is at least 120 km from the central gyre, have reached a nearly identical and stable regime. It has been clarified that long-term dynamic eddy modulation through eddy fluxes, facilitating the freshwater redistribution, affects the meridional asymmetry of the BG halocline. Our results provide a better understanding of the eddy modulation processes and their influence on the halocline structure.\n","PeriodicalId":19535,"journal":{"name":"Ocean Science","volume":"34 1","pages":""},"PeriodicalIF":4.1000,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Long-term eddy modulation affects the meridional asymmetry of the halocline in the Beaufort Gyre\",\"authors\":\"Jinling Lu, Ling Du, Shuhao Tao\",\"doi\":\"10.5194/os-19-1773-2023\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. Against the background of wind-forcing change along with Arctic sea ice retreat, the mesoscale processes undergoing distinct variation in the Beaufort Gyre (BG) region are increasingly important to oceanic transport and energy cascades, and these changes subsequently put oceanic stratification into a new state. Here, the varying number and strength of eddies in the central Canada Basin (CB) and Chukchi–Beaufort continental slope are obtained based on mooring observations (2003–2018), altimetry measurements (1993–2019), and reanalysis data (1980–2020). In this paper, the variability in the BG halocline, representing the adjustment of stratification in the upper layer, is shown in order to analyse how variability occurs under changing mesoscale processes. We find that over almost the last 2 decades the halocline depth has deepened by ∼ 40 m in the south of the central gyre, while that in the north has deepened by ∼ 70 m according to multiple datasets. Surrounding the central gyre, the asymmetry of the halocline, with much steeper and deeper isopycnals over the southern continental slope, reduced after 2014. In the meantime, eddy activities in the upper layer from the southern margin of the BG to the abyssal plain have been enhanced. Moreover, the convergence of the eddy lateral flux has increased as the halocline structures on either side, which is at least 120 km from the central gyre, have reached a nearly identical and stable regime. It has been clarified that long-term dynamic eddy modulation through eddy fluxes, facilitating the freshwater redistribution, affects the meridional asymmetry of the BG halocline. Our results provide a better understanding of the eddy modulation processes and their influence on the halocline structure.\\n\",\"PeriodicalId\":19535,\"journal\":{\"name\":\"Ocean Science\",\"volume\":\"34 1\",\"pages\":\"\"},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2023-12-13\",\"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-19-1773-2023\",\"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-19-1773-2023","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}
Long-term eddy modulation affects the meridional asymmetry of the halocline in the Beaufort Gyre
Abstract. Against the background of wind-forcing change along with Arctic sea ice retreat, the mesoscale processes undergoing distinct variation in the Beaufort Gyre (BG) region are increasingly important to oceanic transport and energy cascades, and these changes subsequently put oceanic stratification into a new state. Here, the varying number and strength of eddies in the central Canada Basin (CB) and Chukchi–Beaufort continental slope are obtained based on mooring observations (2003–2018), altimetry measurements (1993–2019), and reanalysis data (1980–2020). In this paper, the variability in the BG halocline, representing the adjustment of stratification in the upper layer, is shown in order to analyse how variability occurs under changing mesoscale processes. We find that over almost the last 2 decades the halocline depth has deepened by ∼ 40 m in the south of the central gyre, while that in the north has deepened by ∼ 70 m according to multiple datasets. Surrounding the central gyre, the asymmetry of the halocline, with much steeper and deeper isopycnals over the southern continental slope, reduced after 2014. In the meantime, eddy activities in the upper layer from the southern margin of the BG to the abyssal plain have been enhanced. Moreover, the convergence of the eddy lateral flux has increased as the halocline structures on either side, which is at least 120 km from the central gyre, have reached a nearly identical and stable regime. It has been clarified that long-term dynamic eddy modulation through eddy fluxes, facilitating the freshwater redistribution, affects the meridional asymmetry of the BG halocline. Our results provide a better understanding of the eddy modulation processes and their influence on the halocline structure.
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.