珠穆朗玛峰地区新降雪的化学特征

Chemical Characteristics of Fresh Snow in Mount Everest Region

根据 1 998年 8、9月份在珠穆朗玛峰东侧东绒布冰川源头所采集的新降雪样的化学成分资料并与不同时期前人在该地区采集的降水样进行对比 ,初步探讨了该地区降水的化学特征及其气候环境意义 .结果表明 ,珠峰地区夏末降水非常纯净 ,主要离子浓度可与南极和格陵兰地区相当 ,代表了全球偏远地区的大气环境本底值 ;珠峰地区不同季节降水的化学成分有明显的差异 ,反映了不同的水汽来源和气候状况 .8～ 9月的水汽主要来源于南亚季风 ;4～ 5月的降水深受中亚干旱、半干旱区粉尘的影响 ,说明其降水的化学特征具有气候敏感性 .

The chemistry of fresh snow samples collected in August and September, 1998 from Mount Everest was studied and compared with other fresh snow samples collected in different seasons in this region. The results indicated that major species in precipitation were very low in late summer in Mount Everest region and may be representative of the background of precipitation chemistry of remote regions in the wold. Chemical Characteristics of fresh snow in different seasons had distinct differences and they may reflect different moist source and climatic status. The precipitation in August and September was mainly come from Indian summer monsoon and in April and May it was influenced deeply by the dust of semi arid and arid regions in central Asia. This indicates the precipitation in this region is climatic sensitively.