Climate instability in the Yili region, Xinjiang during the last glaciation

The climate is influenced by westerlies year in year out and the aeolian loess is widespread in the Yili region, the Xinjiang Uygur Autonomous Region. Through the study of the loess section with a thickness of 21.5 m, much useful information about climatic change in this region during the last glaciation was gotten. Grain size analysis of loess samples in the section showed that the climatic change in the Yili region was of instability during the last glaciation and similar to those of the North Atlantic Ocean and Greenland. In correspondence with the Heinrich events. the percentage of the size fraction of loess with grain size less than 10 mu m decreased in cold stadials in the Yili region. This result suggests that the westerly wind be strengthened during the cold periods. Compared with the stadials, the content of the loess with grain size less than 10 um was increased in interstadials, which indicated that the strength of the westerly wind was weakened, It is obvious that the climate was instable not only in the North Atlantic Ocean and polar regions. but also in other areas of Northern Hemisphere during the last glaciation.