【摘要】 １９９６夏季，中美联合冰川考察队在西藏南部希夏邦马地区进行联合冰川学综合考察，期间在多处进行了降水样收集和冰川表面积雪的采集，为希夏邦马冰川冰芯中古环境气候记录的解释奠定基础．此外，还进行了同步气象观测．比较分析希夏邦马降水中氧稳定同位素、化学成分变化特征和冰川表面的沉积记录．结果发现希夏邦马夏季降水中氧稳定同位素含量和气温变化并未表现出相关性，但其“高程效应”却十分明显；降水中各离子成分的变化幅度很大，但除ＮＯ－３之外，其变化具有明显的同步性；海拔高度的变化对冰川沉积记录的保存产生重要的影响；如果海拔高度偏低，由融化所导致的淋溶作用会改变雪层中的环境信息记录．更多还原

【Abstract】 Precipitation and snow pits were sampled at different sites at Xixiabangma,south of the Tibetan Plateau,in a Sino American Glaciological Expedition during the summer of 1996.Meteorological data were also collected by an auto observation system.The water samples were analyzed for δ 18 O and ions.The study results indicate that there is no clear correlation between δ 18 O in precipitation and temperature.Nevertheless,δ 18 O in precipitation at Xixiabangma shows an obvious “altitude effect”.The amplitude of ion concentration variations is large,and the variations of various ions in precipitation are generally in the same phase except the variation of NO - 3.A comparison of the variations of δ 18 O and various ions between precipitation samples and snow pit samples show that the glacier records in 6400m have been modified by modern processes,whereas at 7000m,the glacier records are well preserved.更多还原