【摘要】 根据青藏高原拉萨气象站１９９３～１９９６年雨季降水中δ１８Ｏ的测量和ＩＡＥＡ／ＷＭＯ的观测结果，分析了拉萨雨季降水中δ１８Ｏ的变化规律，以及与气温和降水之间的关系。受青藏高原季风的影响，拉萨降水季节变化异常明显，降水集中在夏半年，尤其是７～９月份。拉萨降水中δ１８Ｏ也表现出季风降水的典型特征。降水中δ１８Ｏ“雨量效应”明显，而且这种降水量的影响远远掩盖了气温对降水中δ１８Ｏ的作用。高降水对应降水中δ１８Ｏ低值，反之亦然。拉萨降水中δ１８Ｏ的这种变化特征与青藏高原北部是不同的。更多还原

【Abstract】 The oxygen isotope in precipitation collected at Lhasa Meteorological Station from 1993 to 1996 toghther with the observation by IAEA/WMO are analyzed in this paper. Precipitation concentrates mainly in the warm half year, especially in July, August and September. δ 18 O in summer precipitation has a clear signal of monsoon precipitation. There is no positive correlation between δ 18 O and temperature neither for the variation of the total precipitation samples nor for the seasonal variation, but there is a clear amount effect. The amount effect has overshadowed the temperature effect at Lhasa. This is just opposite to that of the Delingha Station in the north of the Tibetan Plateau where the effect of the southwest monsoon is quite limited.更多还原