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The climatic cyclicity in semiarid‐arid central Asia over the past 500,000 years
Author(s) -
Cheng H.,
Zhang P. Z.,
Spötl C.,
Edwards R. L.,
Cai Y. J.,
Zhang D. Z.,
Sang W. C.,
Tan M.,
An Z. S.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl050202
Subject(s) - stalagmite , speleothem , westerlies , paleoclimatology , arid , climatology , pluvial , precipitation , climate change , cave , monsoon , aridification , marine isotope stage , east asian monsoon , ice core , geology , northern hemisphere , physical geography , glacial period , holocene , geography , interglacial , oceanography , paleontology , archaeology , meteorology
Central Asia is currently a semiarid‐arid region, dominated by the Westerlies. It is important to understand mechanisms of climate and precipitation changes here, as water availability in the region is crucial today and in the future. High‐resolution, absolutely‐dated oxygen isotope ( δ 18 O) records of stalagmites from Kesang Cave characterize a dynamic precipitation history over most of the past 500,000 years. This record demonstrates, for the first time, that climate change in the region exhibits a processional rhythm with abrupt inceptions of low δ 18 O speleothem growth at times of high Northern Hemisphere summer insolation followed by gradual δ 18 O increases that track decreases of insolation. These observations and interpretations contrast with the interpretation of nearby, but higher elevation ice core records. The absolutely‐dated cave δ 18 O shifts can be used to correlate the regional climate variability by providing chronological marks. Combined with other paleoclimate records, the Kesang observations suggest that possible incursions of Asian summer monsoon rainfall or related moisture into the Kesang site and/or adjacent areas during the high insolation times may play an important role in changing orbital‐scale hydrology of the region. Based on our record, arid climate will prevail in this region for the next several millennia, providing that anthropogenic effects do not supersede natural processes.