Subtropical countercurrent variations in cooling climates induced by freshwater forcing over the subarctic North Atlantic

doi:10.1007/s00382-018-4293-1

	Subtropical countercurrent variations in cooling climates induced by freshwater forcing over the subarctic North Atlantic
	Zhang, Cunjie 1,2; Lin, Xiaopei 1,2; Zhang, Cong 3,4; Guo, Yongqing 1,2
刊名	CLIMATE DYNAMICS
	2019-03
卷号	52 期号:5-6 页码:2799-2812
关键词	Subtropical countercurrent Substantially weakened AMOC Bering strait Mode waters
ISSN号	0930-7575
DOI	10.1007/s00382-018-4293-1
英文摘要	The subtropical countercurrent (STCC) could affect ocean eddy activity and the atmosphere above. How the STCC varied in a cooling scenario, such as the stadials during the last deglaciation (19-11ka; ka=1000 years ago), is still unclear. By 1-Sv (1Sv=10(6) m(3) s(-1)) freshwater hosing over the subpolar North Atlantic to suppress the Atlantic Meridional Overturning Circulation (AMOC), the STCC variations under pre-industrial (PI) and last glacial maximum (LGM, similar to 21ka) conditions are analyzed. In both hosing experiments, the northern hemisphere cools. The upper ocean becomes less stratified, and the wintertime mixed layer deepens in the Kuroshio-Oyashio extension (KOE) region. As a result, more mode waters (similar to 20%) are formed, and they become more vertically uniform. The enhanced mode waters induce a stronger vertical shear and accelerate the STCC based on thermal wind relationship. The strengthened STCC further induces warm ocean temperature and upward air-sea heat flux anomalies along it. While the STCC strengthens in both hosing experiments, the location variations are different. In the PI hosing experiment, the Bering Strait is open. Fresh water enters the North Pacific through the Bering Strait and increases the stratification in the downstream of the KOE region. The mixed layer front shifts westward and induces a robust westward shift of mode waters and the STCC. In the LGM hosing experiment, on the contrast, there is no obvious location shift because the Bering Strait is closed.
资助项目	Qingdao National Laboratory for Marine Science and Technology[2017ASKJ01]
WOS关键词	MERIDIONAL OVERTURNING CIRCULATION ; THERMOHALINE CIRCULATION ; YOUNGER DRYAS ; PACIFIC ; SEA ; VARIABILITY ; RISE ; TEMPERATURE ; SENSITIVITY ; SUBDUCTION
WOS研究方向	Meteorology & Atmospheric Sciences
语种	英语
出版者	SPRINGER
WOS记录号	WOS:000463842700017
内容类型	期刊论文
源URL	[http://ir.fio.com.cn:8080/handle/2SI8HI0U/24764]
专题	自然资源部第一海洋研究所
通讯作者	Lin, Xiaopei
作者单位	1.Ocean Univ China, Phys Oceanog Lab, CIMST, Qingdao 266100, Shandong, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Qingdao 266100, Shandong, Peoples R China 3.State Ocean Adm, Inst Oceanog 1, Qingdao 266061, Shandong, Peoples R China 4.Qingdao Natl Lab Marine Sci & Technol, Lab Reg Oceanog & Numer Modeling, Qingdao 266000, Shandong, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Cunjie,Lin, Xiaopei,Zhang, Cong,et al. Subtropical countercurrent variations in cooling climates induced by freshwater forcing over the subarctic North Atlantic[J]. CLIMATE DYNAMICS,2019,52(5-6):2799-2812.
APA	Zhang, Cunjie,Lin, Xiaopei,Zhang, Cong,&Guo, Yongqing.(2019).Subtropical countercurrent variations in cooling climates induced by freshwater forcing over the subarctic North Atlantic.CLIMATE DYNAMICS,52(5-6),2799-2812.
MLA	Zhang, Cunjie,et al."Subtropical countercurrent variations in cooling climates induced by freshwater forcing over the subarctic North Atlantic".CLIMATE DYNAMICS 52.5-6(2019):2799-2812.