气候变化领域集成服务门户(CCPortal): Winter extreme mixed layer depth south of the kuroshio extension

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DOI	10.1175/JCLI-D-19-0966.1
	Winter extreme mixed layer depth south of the kuroshio extension
	Yu J.; Gan B.; Jing Z.; Wu L.
发表日期	2020
ISSN	0894-8755
起始页码	10419
结束页码	10436
卷号	33 期号:24
英文摘要	Change in the extratropical wintertime-mean mixed layer has been widely studied, given its importance to both physical and biogeochemical processes. With a focus on the south of the Kuroshio Extension region where the mixed layer is deepest in March, this study shows that variation of the synoptic-scale extreme mixed layer depth (MLD) is a better precursor than the monthly mean (or nonextreme) MLD for change in the subtropical mode water formation in spring, based on the NCEP Climate Forecast System Reanalysis (1979-2010). It is found that the extreme MLD events are attributable to the accumulation of excessive surface cooling driven by the synoptic storms that characterize cold-air outbreaks. Particularly, the difference between the extreme and nonextreme MLD is primarily related to differences in the cumulative synoptic heat flux anomalies, while a change in the preconditioning upper-ocean stratification contributes almost equally to both cases. Relative contributions of oceanic and atmospheric forcing to the interannual variation of the extreme MLD are quantified using a bulk mixed layer model. Results show comparable contributions: the preconditioning stratification change accounts for;44% of total variance of the extreme MLD, whereas the convective mixing by surface heat flux and the mechanical stirring by wind stress account for;35% and;13%, respectively. In addition, both the reanalysis and observational data reveal that the extreme and nonextreme MLD has been shallowed significantly during 1979-2010, which is accounted for by the strengthened stratification due to the enhanced ocean surface warming by the Kuroshio heat transport. © 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Climate change; Ocean currents; Atmospheric forcing; Biogeochemical process; Interannual variation; Mechanical stirring; Observational data; Relative contribution; Subtropical mode water formations; Surface heat fluxes; Heat flux; atmospheric convection; biogeochemical cycle; extreme event; heat flux; heat transfer; mixed layer; seasonal variation; synoptic meteorology; Kuroshio Extension; Pacific Ocean
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171518
作者单位	Key Laboratory of Physical Oceanography and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China; Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
推荐引用方式 GB/T 7714	Yu J.,Gan B.,Jing Z.,et al. Winter extreme mixed layer depth south of the kuroshio extension[J],2020,33(24).
APA	Yu J.,Gan B.,Jing Z.,&Wu L..(2020).Winter extreme mixed layer depth south of the kuroshio extension.Journal of Climate,33(24).
MLA	Yu J.,et al."Winter extreme mixed layer depth south of the kuroshio extension".Journal of Climate 33.24(2020).