Separating freshwater flux effects on ENSO in a hybrid coupled model of the tropical Pacific

doi:10.1007/s00382-020-05245-y

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋环流与波动重点实验室

	Separating freshwater flux effects on ENSO in a hybrid coupled model of the tropical Pacific
	Gao, Chuan 1,2,3,4; Zhang, Rong-Hua 1,2,3,4; Karnauskas, Kristopher B.5,6; Zhang, Lei 5; Tian, Feng 1,2,3,4
刊名	CLIMATE DYNAMICS
	2020-04-24
页码	22
关键词	Freshwater flux effects Sea surface salinity Buoyancy flux Feedbacks on ENSO Layer and level ocean models
ISSN号	0930-7575
DOI	10.1007/s00382-020-05245-y
通讯作者	Zhang, Rong-Hua(rzhang@qdio.ac.cn)
英文摘要	Freshwater flux (FWF) at the sea surface, defined as precipitation minus evaporation, is a major atmospheric forcing to the ocean that affects sea surface salinity (SSS) and buoyancy flux (Q(B)). Physically, there exist two pathways through which interannual FWF variability can affect the ocean: one through SSS and the other through Q(B). The roles of the interannual FWF variability in modulating the El Nino-Southern Oscillation (ENSO) through its effects on SSS or Q(B) are separately examined using a hybrid coupled model (HCM) of the tropical Pacific; its ocean component is a layer model in which the topmost layer (the first layer) is treated as a mixed layer (ML) whose depth (H-m) is explicitly predicted using an embedded bulk ML model with H-m being directly affected by Q(B), whereas in level ocean models, Q(B) does not have a direct and explicit effect on H-m. Four experiments are conducted using the HCM that is designed to illustrate the effects of these processes on coupled simulations systematically. It is demonstrated that interannual FWF variability serves as a positive feedback on ENSO through its collective effects on both SSS and Q(B). Individually, the interannual FWF effect through SSS accounts for about 80% in terms of ENSO amplitude in the Nino 3.4 area, while that through buoyancy flux accounts for about 26%. This indicates that ocean models without explicitly taking into account the direct FWF effect on Q(B) (typically in level ocean models) could underestimate the positive feedback on ENSO compared with layer ocean models in which the FWF effects are collectively represented on both SSS and Q(B). Further implications for model biases associated with FWF effects are discussed.
资助项目	National Key Research and Development Program of China[2017YFC1404102(2017YFC1404100)] ; National Natural Science Foundation of China[41705082] ; National Natural Science Foundation of China[41690122(41690120)] ; National Natural Science Foundation of China[41421005] ; NSFC-Shandong Joint Fund for Marine Science Research Centers[U1406402] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA19060102] ; Taishan Scholarship
WOS研究方向	Meteorology & Atmospheric Sciences
语种	英语
出版者	SPRINGER
WOS记录号	WOS:000528435500002
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/167307]
专题	海洋研究所_海洋环流与波动重点实验室
通讯作者	Zhang, Rong-Hua
作者单位	1.Pilot Natl Lab Marine Sci & Technol, Qingdao 266237, Peoples R China 2.Chinese Acad Sci, Inst Oceanol, CAS Key Lab Ocean Circulat & Waves, Qingdao 266071, Peoples R China 3.Chinese Acad Sci, Ctr Ocean Megasci, Qingdao 266071, Peoples R China 4.Univ Chinese Acad Sci, Beijing 10029, Peoples R China 5.Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA 6.Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA
推荐引用方式 GB/T 7714	Gao, Chuan,Zhang, Rong-Hua,Karnauskas, Kristopher B.,et al. Separating freshwater flux effects on ENSO in a hybrid coupled model of the tropical Pacific[J]. CLIMATE DYNAMICS,2020:22.
APA	Gao, Chuan,Zhang, Rong-Hua,Karnauskas, Kristopher B.,Zhang, Lei,&Tian, Feng.(2020).Separating freshwater flux effects on ENSO in a hybrid coupled model of the tropical Pacific.CLIMATE DYNAMICS,22.
MLA	Gao, Chuan,et al."Separating freshwater flux effects on ENSO in a hybrid coupled model of the tropical Pacific".CLIMATE DYNAMICS (2020):22.