干旱区生态环境知识资源中心(Arid): The origin of Asian monsoons: a modelling perspective

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DOI	10.5194/cp-16-847-2020
	The origin of Asian monsoons: a modelling perspective
	Tardif, Delphine 1; Fluteau, Frederic 1; Donnadieu, Yannick 2; Le Hir, Guillaume 1; Ladant, Jean-Baptiste 3; Sepulchre, Pierre 4; Licht, Alexis 5; Poblete, Fernando 6; Dupont-Nivet, Guillaume 7,8
通讯作者	Tardif, Delphine
来源期刊	CLIMATE OF THE PAST
ISSN	1814-9324
EISSN	1814-9332
出版年	2020
卷号	16 期号:3 页码:847-865
英文摘要	The Cenozoic inception and development of the Asian monsoons remain unclear and have generated much debate, as several hypotheses regarding circulation patterns at work in Asia during the Eocene have been proposed in the few last decades. These include (a) the existence of modern-like monsoons since the early Eocene; (b) that of a weak South Asian monsoon (SAM) and little to no East Asian monsoon (EAM); or (c) a prevalence of the Intertropical Convergence Zone (ITCZ) migrations, also referred to as Indonesian-Australian monsoon (I-AM). As SAM and EAM are supposed to have been triggered or enhanced primarily by Asian palaeogeographic changes, their possible inception in the very dynamic Eocene palaeogeographic context remains an open question, both in the modelling and field-based communities. We investigate here Eocene Asian climate conditions using the IPSL-CM5A2 (Sepulchre et al., 2019) earth system model and revised palaeogeographies. Our Eocene climate simulation yields atmospheric circulation patterns in Asia substantially different from modern conditions. A large high-pressure area is simulated over the Tethys ocean, which generates intense low tropospheric winds blowing southward along the western flank of the proto-Himalayan-Tibetan plateau (HTP) system. This low-level wind system blocks, to latitudes lower than 10 degrees N, the migration of humid and warm air masses coming from the Indian Ocean. This strongly contrasts with the modern SAM, during which equatorial air masses reach a latitude of 20-25 degrees N over India and southeastern China. Another specific feature of our Eocene simulation is the widespread subsidence taking place over northern India in the midtroposphere (around 5000 m), preventing deep convective updraught that would transport water vapour up to the condensation level. Both processes lead to the onset of a broad arid region located over northern India and over the HTP. More humid regions of high seasonality in precipitation encircle this arid area, due to the prevalence of the Intertropical Convergence Zone (ITCZ) migrations (or Indonesian-Australian monsoon, I-AM) rather than monsoons. Although the existence of this central arid region may partly result from the specifics of our simulation (model dependence and palaeogeographic uncertainties) and has yet to be confirmed by proxy records, most of the observational evidence for Eocene monsoons are located in the highly seasonal transition zone between the arid area and the more humid surroundings. We thus suggest that a zonal arid climate prevailed over Asia before the initiation of monsoons that most likely occurred following Eocene palaeogeographic changes. Our results also show that precipitation seasonality should be used with caution to infer the presence of a monsoonal circulation and that the collection of new data in this arid area is of paramount importance to allow the debate to move forward.
类型	Article
语种	英语
国家	France ; USA ; Chile ; Germany
开放获取类型	Green Submitted, gold
收录类别	SCI-E
WOS记录号	WOS:000531869000001
WOS关键词	EARTH SYSTEM MODEL ; EARLY EOCENE ; TIBETAN PLATEAU ; CLIMATE-CHANGE ; OLIGOCENE CLIMATE ; SUMMER MONSOON ; GLOBAL MONSOON ; ICE-SHEET ; PART I ; CHINA
WOS类目	Geosciences, Multidisciplinary ; Meteorology & Atmospheric Sciences
WOS研究方向	Geology ; Meteorology & Atmospheric Sciences
来源机构	French National Research Institute for Sustainable Development
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/319072
作者单位	1.Univ Paris, CNRS, Inst Phys Globe Paris, F-75005 Paris, France; 2.Aix Marseille Univ, CNRS, IRD, Coll France,INRA,CEREGE, Aix En Provence, France; 3.Univ Michigan, Dept Earth & Environm Sci, Ann Arbor, MI 48109 USA; 4.Univ Paris Saclay, CEA CNRS UVSQ, LSCE IPSL, Lab Sci Climat & Environm, F-91191 Gif Sur Yvette, France; 5.Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA; 6.Univ Chile, Dept Geol, Santiago, Chile; 7.Univ Rennes, Geosci Rennes, CNRS, F-35000 Rennes, France; 8.Univ Potsdam, Inst Geosci, Potsdam, Germany
推荐引用方式 GB/T 7714	Tardif, Delphine,Fluteau, Frederic,Donnadieu, Yannick,et al. The origin of Asian monsoons: a modelling perspective[J]. French National Research Institute for Sustainable Development,2020,16(3):847-865.
APA	Tardif, Delphine.,Fluteau, Frederic.,Donnadieu, Yannick.,Le Hir, Guillaume.,Ladant, Jean-Baptiste.,...&Dupont-Nivet, Guillaume.(2020).The origin of Asian monsoons: a modelling perspective.CLIMATE OF THE PAST,16(3),847-865.
MLA	Tardif, Delphine,et al."The origin of Asian monsoons: a modelling perspective".CLIMATE OF THE PAST 16.3(2020):847-865.