DOI: 10.1016/j.gloplacha.2015.03.004
论文题名: The middle Holocene climatic records from Arabia: Reassessing lacustrine environments, shift of ITCZ in Arabian Sea, and impacts of the southwest Indian and African monsoons
作者: Enzel Y. ; Kushnir Y. ; Quade J.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2015
卷: 129 起始页码: 69
结束页码: 91
语种: 英语
英文关键词: African monsoon
; Arabia
; Holocene paleoclimate
; Indian monsoon
; ITCZ
; Lake
; Somali jet
Scopus关键词: Arid regions
; Atmospheric thermodynamics
; Climate change
; Lakes
; Wetlands
; African monsoons
; Arabia
; Indian monsoon
; ITCZ
; Paleoclimates
; Rain
; climate change
; climate modeling
; Holocene
; moisture content
; paleoclimate
; rainfall
; Arabian Peninsula
; Arabian Sea
; Indian Ocean
英文摘要: A dramatic increase in regional summer rainfall amount has been proposed for the Arabian Peninsula during the middle Holocene (ca. 9-5. ka BP) based on lacustrine sediments, inferred lake levels, speleothems, and pollen. This rainfall increase is considered primarily the result of an intensified Indian summer monsoon as part of the insolation-driven, northward shift of the boreal summer position of the Inter-Tropical Convergence Zone (ITCZ) to over the deserts of North Africa, Arabia, and northwest India. We examine the basis for the proposed drastic climate change in Arabia and the shifts in the summer monsoon rains, by reviewing paleohydrologic lacustrine records from Arabia. We evaluate and reinterpret individual lake-basin status regarding their lacustrine-like deposits, physiography, shorelines, fauna and flora, and conclude that these basins were not occupied by lakes, but by shallow marsh environments. Rainfall increase required to support such restricted wetlands is much smaller than needed to form and maintain highly evaporating lakes and we suggest that rainfall changes occurred primarily at the elevated edges of southwestern, southern, and southeastern Arabian Peninsula. These relatively small changes in rainfall amounts and local are also supported by pollen and speleothems from the region. The changes do not require a northward shift of the Northern Hemisphere summer ITCZ and intensification of the Indian monsoon rainfall. We propose that (a) latitudinal and slight inland expansion of the North African summer monsoon rains across the Red Sea, and (b) uplifted moist air of this monsoon to southwestern Arabia highlands, rather than rains associated with intensification of Indian summer monsoon, as proposed before, increased rains in that region; these African monsoon rains produced the modest paleo-wetlands in downstream hyperarid basins. Furthermore, we postulate that as in present-day, the ITCZ in the Indian Ocean remained at or near the equator all year round, and the Indian summer monsoon, through dynamically induced air subsidence, can reduce rather than enhance summer rainfall in the Levant and neighboring deserts, including Arabia. Our summary suggests a widening to the north of the latitudinal range of the rainfall associated with the North African summer monsoon moisture crossing the Red Sea to the east. We discuss other mechanisms that could have potentially contributed to the formation and maintaining of the modest paleo-wetlands. © 2015 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84927729934&doi=10.1016%2fj.gloplacha.2015.03.004&partnerID=40&md5=db8c08ac63c6cdbd43fcbc038f87a0b7
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11532
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: The Fredy and Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
Recommended Citation:
Enzel Y.,Kushnir Y.,Quade J.. The middle Holocene climatic records from Arabia: Reassessing lacustrine environments, shift of ITCZ in Arabian Sea, and impacts of the southwest Indian and African monsoons[J]. Global and Planetary Change,2015-01-01,129.