Impact of the Deep Chlorophyll Maximum in the Equatorial Pacific as Revealed in a Coupled Ocean GCM-Ecosystem Model

doi:10.1029/2022JC018631

IOCAS-IR > 海洋环流与波动重点实验室

	Impact of the Deep Chlorophyll Maximum in the Equatorial Pacific as Revealed in a Coupled Ocean GCM-Ecosystem Model
	Shi, Qidong 1,2; Zhang, Rong-Hua2,3,4 ; Tian, Feng 1,4
	2023-04-01
发表期刊	JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
ISSN	2169-9275
卷号	128 期号:4 页码:24
通讯作者	Zhang, Rong-Hua([email protected])
摘要	A coupled ocean general circulation model (OGCM)-ocean ecosystem model is used to investigate the effects of the deep chlorophyll maximum (DCM) on the ocean state in the equatorial Pacific Ocean. Climatological and interannual three-dimensional (3-D) chlorophyll (CHL) fields are captured well in control runs using the coupled ocean physics-ecosystem model forced by prescribed atmospheric fields. Further sensitivity experiments are performed to assess the effects of 3-D CHL structure using the OGCM with the prescribed CHL fields taken from the control runs: CHLclim and CHLclimsurf are runs in which climatological DCM effect is included or only surface CHL effect is included; CHLinter and CHLintersurf inter are runs with interannually varying DCM effects included or not. The differences in the simulated ocean conditions are analyzed to explore DCM effects on sea surface temperature (SST) and amplitude of El Nino-Southern Oscillation (ENSO). Two competing mechanisms responsible for the DCM effects are revealed: an ocean biology-induced direct heating (OBH) effect, and an indirect cooling effect due to dynamic processes associated with vertical mixing and shallow meridional overturning circulation. There are three major findings: (a) DCM acts to reduce mean SST by around 0.2 degrees C in the eastern equatorial Pacific, being larger than the surface CHL effects. (b) DCM interannual variability increases the ENSO amplitude to a comparable degree as the surface CHL effects. (c) The total net impact of vertical mixing, currents, and net surface heat flux makes SST drop more under the DCM effect than the surface CHL effect in the eastern Pacific. These findings provide a new insight into the feedback mechanisms for the bioclimate interactions. Plain Language Summary Ocean chlorophyll (CHL) concentration is influenced by physical conditions in the ocean, such as El Nino-Southern Oscillation (ENSO), and has a feedback effect on ENSO by absorbing solar radiation in the upper ocean. CHL is usually seen to have a maximum below the mixed layer due to the vertical distribution of light and nutrients, forming a deep chlorophyll maximum (DCM). However, the specific effects of DCM on physical properties and the related mechanisms in the equatorial Pacific have not been understood well. In this study, we examine the impact of DCM on the physical oceanography in the tropical Pacific, using a coupled ocean general circulation model (OGCM)-ocean ecosystem model. By performing sensitivity experiments with the DCM effects included or not, it is found that the existence of DCM effects acts to reduce climatological SST in the eastern equatorial Pacific and increase ENSO amplitude. Two competing mechanisms are identified that can be responsible for the DCM effects: one is a direct warming due to increased absorption of solar radiation in the mixed layer, and the other is an indirect cooling due to processes induced by the former.
DOI	10.1029/2022JC018631
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[42030410]; National Natural Science Foundation of China[LSKJ202202402]; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB 42000000]; Startup Foundation for Introducing Talent of NUIST; NSFC[42006001]
WOS研究方向	Oceanography
WOS类目	Oceanography
WOS记录号	WOS:001000243600008
出版者	AMER GEOPHYSICAL UNION
WOS关键词	TROPICAL PACIFIC ; GENERAL-CIRCULATION ; PENETRATIVE RADIATION ; COLOR DATA ; CLIMATE ; FEEDBACKS ; ENSO ; BIOLOGY ; TEMPERATURE ; VARIABILITY
引用统计
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/182253
专题	海洋环流与波动重点实验室
通讯作者	Zhang, Rong-Hua
作者单位	1.Chinese Acad Sci, Inst Oceanol, CAS Key Lab Ocean Circulat & Waves, Qingdao, Peoples R China 2.Univ Chinese Acad Sci, Beijing, Peoples R China 3.Nanjing Univ Informat Sci & Technol, Sch Marine Sci, Nanjing, Peoples R China 4.Laoshan Lab, Qingdao, Peoples R China
第一作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	Shi, Qidong,Zhang, Rong-Hua,Tian, Feng. Impact of the Deep Chlorophyll Maximum in the Equatorial Pacific as Revealed in a Coupled Ocean GCM-Ecosystem Model[J]. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,2023,128(4):24.
APA	Shi, Qidong,Zhang, Rong-Hua,&Tian, Feng.(2023).Impact of the Deep Chlorophyll Maximum in the Equatorial Pacific as Revealed in a Coupled Ocean GCM-Ecosystem Model.JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,128(4),24.
MLA	Shi, Qidong,et al."Impact of the Deep Chlorophyll Maximum in the Equatorial Pacific as Revealed in a Coupled Ocean GCM-Ecosystem Model".JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 128.4(2023):24.