Lambert冰川流域东西两侧大气降水的化学特征

1992～1993年,中国科学家参加了澳大利亚南极考察队对Lambert冰川流域西侧的考察,1996年起中国南极考察队对Lambert流域东侧进行了多次考察.本文基于以上考察的研究成果,对Lambert冰川流域东西两侧大气降水的化学特征进行了对比研究.结果表明:Lambert冰川流域东西两侧在1932～1992年,各种离子均有较大的年际变化和年代际变化,东侧过去60年来海盐离子浓度呈现升高趋势,而西侧则呈现下降趋势,可能反映了东西两侧水汽输送能力存在明显的差异.同时,对东西两侧雪冰中的离子浓度进行了EOF分析,表明Lambert冰川流域东西两侧降水中的化学成分主要来源于海盐传输、中低纬度远距离传输和高纬地区局地来源.

Chemical characteristics of precipitation on both sides of the Lambert Glacier Basin

During 1992-1993 joint Australian/Chinese oversnow traverse on the western side of Lambert Glacier Basin (LGB), one firn core was drilled at LGB16. During 1996-1997 austral summer, a firn core was drilled at DT001 on the eastern side of LGB. Based on the achievements made during the expeditions, the chemical characteristics of precipitation on both sides of LGB have been studied. Results show that the annual to decadal variations of major ion concentrations in the firn cores recovered from both sides of LGB are large. The variation trends of sea salt ion concentrations in the firn core recovered from eastern side of LGB show increasing trend while those in the firn core recovered from western side of LGB show decreasing trend which may be reflect the different moisture resources between the eastern side of LGB and the western side of LGB. The results of EOF (Empirical Orthogonal Function) analysis indicate that the chemicals in precipitation in both sides of LGB originate from sea salts, low and intermediate latitude regions and local sources.