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DOI	10.1007/s00382-018-4444-4
	Atlantic salinity budget in response to Northern and Southern Hemisphere ice sheet discharge
	van den Berk J.; Drijfhout S.S.; Hazeleger W.
发表日期	2019
ISSN	0930-7575
起始页码	5249
结束页码	5267
卷号	52 期号:2020-09-10
英文摘要	The impact of an idealised scenario of future mass release of major ice sheets on the Atlantic ocean is studied. A freshwater forcing is applied to the ocean surface in a coupled climate model forced in accordance with a high-end future climate projection for mass loss from the Greenland and Antarctic ice-sheet, together with the RCP8.5 emission scenario. The added freshwater dilutes the entire ocean by increasing total volume, but changes in freshwater budget are non-linear in time, especially in the Atlantic Ocean. In the Atlantic the initial dilution mainly comes from Greenland freshwater, but the increase in mass is counteracted by the mass flux across the boundaries of the Atlantic, with the outflow into the Southern Ocean becoming larger than the inflow through Bering Strait. Associated with this mass divergence, salt is exported to the Southern Ocean by the barotropic flow. Further freshening is associated with more freshwater import by the Atlantic Meridional Overturning Circulation across the southern boundary of the Atlantic. Also, the subtropical gyre exports salt and imports freshwater across the Atlantic’s southern boundary, especially when freshwater from the Antarctic Ice Sheet arrives at the boundary of the basin. It appears that the response to Northern Hemisphere (NH) sources (the Greenland Ice Sheet) and Southern Hemisphere (SH) sources (the Antarctic Ice Sheet) are opposite. In the case of NH-only freshwater forcing, sea surface height (SSH) increases in the Arctic, causing a reduction of the SSH gradient over the Bering Strait, and hence the barotropic throughflow across the Arctic–Atlantic basin reduces. In case of SH-only freshwater forcing, SSH increases in the Pacific, enhancing the barotropic throughflow in the Arctic–Atlantic. When both NH and SH freshwater forcings are present, the response in the Atlantic is dominated by NH forcing. Changes in overturning transport to either NH or SH forcing counteract the response to changes in barotropic transport. These changes are not due to volume transport but mainly due to salinity changes, in particular across the southern boundary of the Atlantic. Only when both SH and NH freshwater forcing are present changes in barotropic transport and overturning transport reinforce each other: the barotropic transport more strongly reacts to NH forcing, while the overturning transport reacts more strongly to SH forcing. © 2018, The Author(s).
英文关键词	Atlantic Ocean; Coupled climate models; Meltwater; Salinity budget
语种	英语
scopus关键词	air-sea interaction; climate modeling; discharge; ice sheet; meltwater; Northern Hemisphere; outflow; salinity; Southern Hemisphere; Antarctic Ice Sheet; Antarctica; Arctic; Atlantic Ocean; Bering Strait; Greenland; Southern Ocean
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146359
作者单位	Royal Netherlands Meteorological Institute, De Bilt, Netherlands; School of Ocean and Earth Science, University of Southampton, Southampton, United Kingdom; Wageningen University, Wageningen, Netherlands; Netherlands eScience Center, Amsterdam, Netherlands
推荐引用方式 GB/T 7714	van den Berk J.,Drijfhout S.S.,Hazeleger W.. Atlantic salinity budget in response to Northern and Southern Hemisphere ice sheet discharge[J],2019,52(2020-09-10).
APA	van den Berk J.,Drijfhout S.S.,&Hazeleger W..(2019).Atlantic salinity budget in response to Northern and Southern Hemisphere ice sheet discharge.Climate Dynamics,52(2020-09-10).
MLA	van den Berk J.,et al."Atlantic salinity budget in response to Northern and Southern Hemisphere ice sheet discharge".Climate Dynamics 52.2020-09-10(2019).