巴丹吉林沙漠更新世古风向变化及环境意义

古大气环流研究旨在揭示高大沙山形成发育过程中地表风系的变化和大气环流形式。通过对巴丹吉林沙漠的沙山形态、沙山地层测年、古沙丘层理结构以及区域风况等的综合研究 ,表明末次间冰期以前该区主要受西风环流控制 ,地表盛行风向为西风 ,次为西北风 ,河湖水系较发育 ;末次冰期以来该区主要受东亚季风环流影响 ,地表盛行风向为西北风 ,次为西风 ,风沙活动居主导地位。古风向变化可能是青藏高原隆升对西风环流的阻挡与对东亚季风环流强化的具体表现

Pleistocene paleowind direction change in the Badain Jaran desert and its environmental significance

High megadunes in the Badain Jaran desert, seldom seen in the other sand sea of the world, are origined from the long time coupling of airflow with underlying sandy terrain. Based on the analysis of dune types and distribution features of dune types, dune strata and TL dating, fossil dune cross bedding orientation and wind data etc, it indicates that the prevailing palaeowind regime in the Badain Jaran Desert area is at variance throughout the quaternary. Before last glaciations westerly winds originating from westerly circulation predominated but that there is a relatively important northwest wind caused by East Asian monsoon circulation in the processes of megadune occurrence, and since last glaciations northwest winds dominated the area but there is a relatively important westerly wind at the time of high megadune growth. These also imply that prevailing wind direction change in the area may be resulted from the obstruction of westerly wind circulation and the strength of East Asian monsoon circulation caused by the uplift of Qinghai Tibet plateau.