中文摘要：

根据2004年5月至2005年6月广州日大气降水中δ^18O资料和GNIP提供的广州、香港多年月平均降水中δD、δ^18O资料，研究了天气尺度下广州大气降水中δ^18O与降水量、水汽压、气温和露点温度等气象要素之间的关系，并就季风活动对本地降水中δ^18O的影响作了初步分析．结果表明：在天气尺度下，广州大气降水中δ^18O与降水量、水汽压、气温和露点温度均存在显著的负相关关系，同温度露点差存在显著的正相关关系，表明广州大气降水中δ^18O变化具有显著的降水量效应和湿度效应．夏季风期间季风活动对天气尺度下降水中δ^18O的变化具有显著影响，使得天气尺度下大气降水中δ^18O变化有时并不遵循降水量效应．从多年气候平均状况来看，广州、香港降水中δ^18O的季节变化同亚洲夏季风的爆发和推进演变过程较为相似，在夏季风活跃的时期，大气降水中δ^18O值也较低，反映了季风降水再循环活动对降水中稳定同位素含量具有显著影响．

英文摘要：

Based on the data of daily δ^18O in precipi tation in Guangzhou Station from May, 2004 to June, 2005 and the monthly δD, δ^18O data of Guangzhou and Hongkong provided by GNIP, the relationships between the δ^18O in precipitation and the precipitation amount, air pressure, temperature and dew-point temperature on the synoptic timescale are analyzed, and the effect of monsoon activity on δ^18O in precipitation is also discussed in this paper. The results indicate that the meteoric water line equations for Guangzhou and Honking are basically identical, which reflects the comparability of precipitation, raining sources and their characteristics as well as the effect of monsoon activity in the two areas. There appear marked negative correlations of the δ^18O in precipitation with precipitation amount, air pressure, temperature and dewpoint temperature and a notable positive correlation with the dew-point deficit on the synoptic timescale. The summer monsoon activity has great effect on the variation of the δ^18O in precipitation, which makes the δ^18O in precipitation offend the precipitation amount effect sometimes on the synoptic timescale. In addition, the seasonal variations of the δ^18O in precipitation in Guangzhou and Hongkong are comparatively similar to the evolvement courses of the Asian monsoon. The δ^18O in precipitation is commonly lower during the active period of the summer monsoon, and this indicates that the recycle course of the monsoon precipitation has marked effect on the content of stable oxygen isotope in precipitation.