【摘要】 利用1961—2000年高原91个站的气象实测资料并结合高原沙区分布状况,分析了近40a青藏高原沙尘暴的时空分布特征。结果表明,高原具备发生沙尘暴的前提条件,大片的流动沙丘和大片荒漠化土地为沙尘暴的发生提供了充足的沙源,年沙尘暴发生频率非常高,大体有以羌塘高原为中心向东南逐渐减少的趋势。从12月至翌年4月,沙尘暴发生中心从藏南的雅鲁藏布江上游河谷地区依次逐渐向北扩展到羌塘高原南部、羌塘高原及塔里木盆地南部,这种季节性摆动与副热带西风急流的位置变化密切相关,加上高原海拔4000～5000m的高度,细粒物质被轻松地扬升到西风急流区,传往遥远的北太平洋地区,高原成为远程传输最高效的沙尘源地之一。沉降在北太平洋的沙尘,加强了海洋生物泵的效率,进而可能对全球气候产生影响。更多还原

【Abstract】 Based on the distribution of sand regions and the available observation data from 91 meteorological stations during 1961—2000, the spatio-temporal distribution characters of sandstorms in Qinghai-Tibet Plateauare discussed. The Qinghai-Tibet Plateau possesses all factors resulting in sand-dust storm. The widespread moving sand dune and desertified land in the plateau provide sufficient sand source, which combing with arid climate and prevailing wind induce that sand-dust storm occurred at high frequency. The center of sand-dust storm frequently taking place is in the Qiang-Tang Plateau, the annual days gradually decrease from Qiang-Tang to southeast. Monthly, from December to April the center moves northward from upriver valley of Brahmaputra to south of Qiang-Tang Plateau, to center of Qiang-Tang Plateau, and to south of Tarim Basin. Such seasonal shifting of the center is closely related with the position swing of westerly jet-stream. In addition, due to high altitude of the Qinghai-Tibet Plateau fine particles in sandstorms may be easily raised up into the westerly jet-stream （500 hPa） and transported to remote North Pacific region. Therefore, the Qinghai-Tibet Plateau is one of the most effective sand-dust source regions of long-distance transportation; sand-dusts settled down in the North Pacific region may play a very important role in global climate change through strengthening the Biological Pump efficiency and possibly changing the atmospheric CO₂concentration.更多还原