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

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.

[1]  J. Overpeck,et al.  Regionalization of present-day precipitation in the greater monsoon region of Asia , 2011 .

[2]  S. Burns,et al.  Holocene and Pleistocene pluvial periods in Yemen, southern Arabia , 2011 .

[3]  M. Stein,et al.  Northward intrusions of low- and mid-latitude storms across the Saharo-Arabian belt during past interglacials , 2010 .

[4]  R. Edwards,et al.  Large variations of oxygen isotopes in precipitation over south-central Tibet during Marine Isotope Stage 5 , 2010 .

[5]  D. Burbank,et al.  Alluvial sequence in the north piedmont of the Chinese Tian Shan over the past 550 kyr and its relationship to climate change , 2010 .

[6]  W. Broecker,et al.  Ice Age Terminations , 2009, Science.

[7]  F. Riedel,et al.  Holocene environments and climate in the Mongolian Altai reconstructed from the Hoton-Nur pollen and diatom records: a step towards better understanding climate dynamics in Central Asia , 2009 .

[8]  T. Stocker,et al.  Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years , 2008, Nature.

[9]  Xiaohua Shao,et al.  Millennial- and orbital-scale changes in the East Asian monsoon over the past 224,000 years , 2008, Nature.

[10]  H. Birks,et al.  Holocene moisture evolution in arid central Asia and its out-of-phase relationship with Asian monsoon history , 2008 .

[11]  P. Tzedakis.  Seven ambiguities in the Mediterranean palaeoenvironmental narrative , 2007 .

[12]  S. Clemens,et al.  East Asian monsoon variability over the last seven glacial cycles recorded by a loess sequence from the northwestern Chinese Loess Plateau , 2006 .

[13]  D. Joswiak,et al.  Climatic and atmospheric circulation pattern variability from ice-core isotope/geochemistry records (Altai, Tien Shan and Tibet) , 2006, Annals of Glaciology.

[14]  M. Bar-Matthews,et al.  Sea-land oxygen isotopic relationships from planktonic foraminifera and speleothems in the Eastern Mediterranean region and their implication for paleorainfall during interglacial intervals , 2003 .

[15]  Manfred Mudelsee,et al.  Holocene Forcing of the Indian Monsoon Recorded in a Stalagmite from Southern Oman , 2003, Science.

[16]  G. A. Wang,et al.  The loess record in southern Tajikistan and correlation with Chinese loess , 2002 .

[17]  P. Tarasov,et al.  Holocene vegetation and climate changes in Hoton‐Nur basin, northwest Mongolia , 2000 .

[18]  E. Mosley‐Thompson,et al.  Tropical Climate Instability: The Last Glacial Cycle from a Qinghai-Tibetan Ice Core , 1997 .

[19]  E. Mosley‐Thompson,et al.  Holocene—Late Pleistocene Climatic Ice Core Records from Qinghai-Tibetan Plateau , 1989, Science.

[20]  J. D. Hays,et al.  The orbital theory of Pleistocene climate : Support from a revised chronology of the marine δ^ O record. , 1984 .

[21]  André Berger,et al.  Long-Term Variations of Caloric Insolation Resulting from the Earth's Orbital Elements , 1978, Quaternary Research.

[22]  C. Hendy,et al.  The isotopic geochemistry of speleothems—I. The calculation of the effects of different modes of formation on the isotopic composition of speleothems and their applicability as palaeoclimatic indicators , 1971 .