MJO-Induced Intraseasonal Mixed Layer Depth Variability in the Equatorial Indian Ocean and Impacts on Subsurface Water Obduction

doi:10.1175/JPO-D-20-0179.1

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

	MJO-Induced Intraseasonal Mixed Layer Depth Variability in the Equatorial Indian Ocean and Impacts on Subsurface Water Obduction
	Liu, Lingling 2,3; Li, Yuanlong 1,2,3; Wang, Fan 2,3
刊名	JOURNAL OF PHYSICAL OCEANOGRAPHY
	2021-04-01
卷号	51 期号:4 页码:1247-1263
关键词	Indian Ocean Entrainment Oceanic mixed layer Intraseasonal variability
ISSN号	0022-3670
DOI	10.1175/JPO-D-20-0179.1
通讯作者	Li, Yuanlong(liyuanlong@qdio.ac.cn)
英文摘要	Change of oceanic surface mixed layer depth (MLD) is critical for vertical exchanges between the surface and subsurface oceans and modulates surface temperature variabilities on various time scales. In situ observations have documented prominent intraseasonal variability (ISV) of MLD with 30-105-day periods in the equatorial Indian Ocean (EIO) where the Madden-Julian oscillation (MJO) initiates. Simulation of Hybrid Coordinate Ocean Model (HYCOM) reveals a regional maximum of intraseasonal MLD variability in the EIO (70 degrees-95 degrees E, 3 degrees S-3 degrees N) with a standard deviation of similar to 14 m. Sensitivity experiments of HYCOM demonstrate that, among all of the MJO-related forcing effects, the wind-driven downwelling and mixing are primary causes for intraseasonal MLD deepening and explain 83.7% of the total ISV. The ISV of MLD gives rise to high-frequency entrainments of subsurface water, leading to an enhancement of the annual entrainment rate by 34%. However, only a small fraction of these entrainment events (<20%) can effectively contribute to the annual obduction rate of 1.36 Sv, a quantification for the amount of resurfacing thermocline water throughout a year that mainly (84.6%) occurs in the summer monsoon season (May-October). The ISV of MLD achieves the maximal intensity in April-May and greatly affects the subsequent obduction. Estimation based on our HYCOM simulations suggests that MJOs overall reduce the obduction rate in the summer monsoon season by as much as 53%. A conceptual schematic is proposed to demonstrate how springtime intraseasonal MLD deepening events caused by MJO winds narrow down the time window for effective entrainment and thereby suppress the obduction of thermocline water.
资助项目	National Natural Science Foundation of China[41976009] ; Strategic Priority Research Program of Chinese Academy of Sciences[XDB42000000] ; Strategic Priority Research Program of Chinese Academy of Sciences[XDB40000000] ; National Key Research and Development Program of China[2017YFC1404002] ; Shandong Provincial Natural Science Foundation[ZR2020JQ17] ; Key Deployment Project of CAS Centre for Ocean Mega-Science[COMS2019Q07]
WOS研究方向	Oceanography
语种	英语
出版者	AMER METEOROLOGICAL SOC
WOS记录号	WOS:000644279200016
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/170949]
专题	海洋研究所_海洋环流与波动重点实验室
通讯作者	Li, Yuanlong
作者单位	1.Chinese Acad Sci, Ctr Excellence Quaternary Sci & Global Change, Xian, Peoples R China 2.Chinese Acad Sci, Ctr Ocean Megasci, Inst Oceanol, Key Lab Ocean Circulat & Waves, Qingdao, Peoples R China 3.Qingdao Natl Lab Marine Sci & Technol, Funct Lab Ocean Dynam & Climate, Qingdao, Peoples R China
推荐引用方式 GB/T 7714	Liu, Lingling,Li, Yuanlong,Wang, Fan. MJO-Induced Intraseasonal Mixed Layer Depth Variability in the Equatorial Indian Ocean and Impacts on Subsurface Water Obduction[J]. JOURNAL OF PHYSICAL OCEANOGRAPHY,2021,51(4):1247-1263.
APA	Liu, Lingling,Li, Yuanlong,&Wang, Fan.(2021).MJO-Induced Intraseasonal Mixed Layer Depth Variability in the Equatorial Indian Ocean and Impacts on Subsurface Water Obduction.JOURNAL OF PHYSICAL OCEANOGRAPHY,51(4),1247-1263.
MLA	Liu, Lingling,et al."MJO-Induced Intraseasonal Mixed Layer Depth Variability in the Equatorial Indian Ocean and Impacts on Subsurface Water Obduction".JOURNAL OF PHYSICAL OCEANOGRAPHY 51.4(2021):1247-1263.