Journal of Geographical Sciences ›› 2019, Vol. 29 ›› Issue (12): 2101-2121.doi: 10.1007/s11442-019-1707-x

• Research Articles • Previous Articles     Next Articles

Moisture sources of the Alashan Sand Seas in western Inner Mongolia, China during the Last Glacial Maximum and mid-Holocene: Interpretation from modern analogues, paleoclimatic simulations and geological records

FENG Yingying1, YANG Xiaoping2()   

  1. 1. Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, CAS, Beijing 100029, China
    2. Department of Geography, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
  • Received:2019-01-26 Accepted:2019-09-09 Online:2019-12-25 Published:2019-12-06
  • Contact: YANG Xiaoping E-mail:xpyang@zju.edu.cn
  • About author:Feng Yingying (1994–), specialized in palaeoclimatic simulations.
  • Supported by:
    National Natural Science Foundation of China, No(41430532);National Natural Science Foundation of China, No(41672182)

Abstract:

Knowledge of moisture sources is of great significance for understanding climatic change and landscape evolution in desert environments. In this paper, we aim to clarify moisture origins for the Alashan (Alxa) Sand Seas (ALSS) in western Inner Mongolia and their transport pathways during the Last Glacial Maximum (LGM) and the mid-Holocene using modern analogues and paleoclimatic simulations. Precipitation data for the period 1959-2015 from meteorological stations in the study area and wind and specific humidity data from the European Center for Medium-Range Weather Forecasts (ECMWF) daily reanalysis were adopted to determine the moisture sources of summer precipitation in the ALSS. In addition paleoclimate simulations under PMIP3/CMIP5 protocols were used to detect the atmospheric circulation and precipitation at 21 ka BP and 6 ka BP over the ALSS. We also reviewed paleoclimate records from the ALSS to acquire a semi-quantitative reconstruction of the moisture history during the late Pleistocene and Holocene. Our results suggest that the summer monsoon transported water vapor from the Indian Ocean and the South China Sea to the ALSS during July and August, causing increased precipitation. The dominant moisture source was from the southwest monsoon, while the East Asian summer monsoon also partly contributed to precipitation in the ALSS. The increased humidity during the period 8.2-4.2 ka BP in the ALSS, as derived from both climate simulation outputs and sedimentary records, was caused by monsoons according to the outputs of simulations. At 21 ka BP, the moisture sources of the ALSS were greatly associated with the prevailing westerlies.

Key words: Badain Jaran Desert, Tengger Desert, Ulan Buh Desert, Asian summer monsoon, westerlies, paleoclimate