2012年6月在祁连山老虎沟12号冰川采集雪坑和表层雪样品,结合相关分析法、海盐示踪法、气团轨迹法等方法,对冰川积雪的主要化学离子特征、来源及环境意义进行分析研究.结果表明,积雪中平均离子浓度Ca2+】SO24-】NH4+】NO3-】Cl-】Na+】Mg2+】K+.雪坑中Ca2+是主要的阳离子,SO24-是主要的阴离子;各种离子在雪坑中的平均浓度要远大于表层雪,而且雪坑中的化学离子浓度峰值与污化层有着很好的对应性.同时,与青藏高原、中亚天山、阿尔泰山以及北半球其他区域高海拔雪冰化学特征进行比较,发现祁连山老虎沟12号冰川区积雪化学特征受亚洲粉尘源区陆源矿物影响较大.然而,雪坑中的离子(尤其是Na+和Cl-)除了陆源矿物粉尘之外,部分还来源于海洋源.结合NOAA Hysplit模型对冰川区积雪化学离子来源进行了后向轨迹反演验证.
Snow chemistry on the glaciers of high mountains is good indicator for studying atmospheric environment change.During the summer of 2006,snow samples were taken from three snowpits at different altitude on the Laohugou Glacier No.12 in the West Qilian Mountains of China,and then snow chemistry characteristics of the samples were measured.Correlation analysis and sea-salt tracing methods were used in this study to reveal the sources of major ions and dust particles.It is found that major ions in the snow have obvious seasonal variation.The major ionic concentrations rank as Ca2+> SO2-4>NH+4>NO-3>Cl->Na+>Mg2+>K+.Ca2+ is the dominate cation,and SO2-4 is the dominate anion.The ionic correlation coefficient analysis shows that all the ions,except NO-3,have very good correlation.The glacier regions are mainly affected by dust activities.Moreover,the major ions,especially Na+ and Cl-,are significantly affected by ocean in west,owing to precipitation mainly coming from west.Besides,there are part ions originating from the dust sources in central Asian.