天山哈密榆树沟6号冰川积雪化学特征及环境意义

Chemistry characteristics and environmental significance of snow deposited on the Yushugou Glacier No. 6, Tianshan Mountains

本研究基于2017年8月和2018年8月在天山榆树沟6号冰川采集的雪坑和表层雪实测资料,通过海盐示踪法、相关分析法、HYSPLIT后向轨迹等方法,对冰川积雪的主要阴阳离子的化学特征进行了分析,并探讨了离子的来源及环境指示意义.研究发现,冰川积雪中平均离子浓度顺序为Ca2+>SO42->Cl->Na+>NO-3>NH+4>Mg2+>K+,其中SO42-和Ca2+分别为主要的阴阳离子.雪坑中各离子平均浓度,pH值、电导率整体高于表层雪,且雪坑中的不溶微粒粉尘和化学离子峰值与污化层具有很好的对应关系.表层雪的化学离子浓度随海拔变化呈先减小后增大的趋势.冰川积雪中的离子来源主要包括,陆源矿物粉尘(Ca2+、Mg2+、K+)、海洋源海盐(Cl-、Na+)、人为源(SO42-、NO-3、NH+4).

We collected snow samples in three snow pits at different altitudes and surface snow on the Yushugou Glacier No.6,Tianshan Mountains,China,during August 2017 and August 2018.Sea-salt tracing methods,correlation analysis and backward trajectory model methods were used in this study to reveal the sources of major ions.The research found that the major ionic concentrations rank was Ca2+>SO42->Cl->Na+>NO-3>NH+4>Mg2+>K+,The SO42-was the dominate anion,and Ca2+was the dominate cation.The average concentration,pH and electrical conductivity of each ion in the snow pit were higher than the surface snow.In addition,the peak value of dust particles and ions in the snow pit corresponded well with the fouling layer.The ions concentration of surface snow showed a tendency of firstly decreased and then increased with the change of altituded.The main sources of ions included mineral dust(Ca2+,Mg2+,K+),sea-salt(Cl-,Na+),anthropogenic sources(SO42-,NH+4,NO-3).