Details

Autor(en) / Beteiligte

• Cheng, H.
• Zhang, P. Z.
• Spötl, C.
• Edwards, R. L.
• Cai, Y. J.
• Zhang, D. Z.
• Sang, W. C.
• Tan, M.
• An, Z. S.

Titel

The climatic cyclicity in semiarid-arid central Asia over the past 500,000 years

Ist Teil von

• Geophysical research letters, 2012-01, Vol.39 (1), p.n/a

Ort / Verlag

Washington, DC: Blackwell Publishing Ltd

Erscheinungsjahr

2012

Quelle

Wiley Online Library

Beschreibungen/Notizen

• 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 (δ18O) 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 δ18O speleothem growth at times of high Northern Hemisphere summer insolation followed by gradual δ18O 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 caveδ18O 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. Key Points Speleothem records characterize 500 ka precipitation history in Central Asia Climatic patterns in the Westerlies region are dominated by a precession rhythm Asian Monsoon incursions may explain the hydrological change on precession scale