珠江三角洲地区降水中δ^(18)O的变化特征及与ENSO的关系

Variations of δ^(18)O in Precipitation in the Zhujiang(Pearl) River Delta and Its Relationship with ENSO Event

根据2004年5月至2005年6月广州降水中δ18O与IAEA/WMO提供的1961~2001年香港降水中δ18O及相关气象资料,分析了珠江三角洲地区降水中δ18O在不同时间尺度下的变化特征及与ENSO事件的关系。在天气尺度和季节尺度下,该地区降水中δ18O与温度、降水量均存在显著的负相关关系;在年际变化上,该地区降水中1δ8O与温度、降水量的关系较为复杂。珠江三角洲地区年平均降水中1δ8O与N ino3区SST和南方涛动指数具有显著的相关性,表明ENSO事件对该地区降水中稳定同位素的变化具有重要影响。

The oxygen isotope in precipitation collected at Guangzhou Wushan meteorological station from May 2004 to June 2005 together with the observation by IAEA/WMO are analyzed under different time scales and its relationship with ENSO event is also analyzed in this paper. Under climatic and seasonal scale, the magnitude of δ^18O has reverse correlations with the temperature and the precipitation respectively. The magnitude of δ^18O in this region has notable precipitation effect but without temperature effect. The seasonal variations of δ^18O in precipitation are evident, resulting from the influences of the monsoon climate and different vapor sources on the isotope composition of precipitation. Under annual scale, there are complicated correlations between the δ^18O in precipitation and the temperature and the precipitation, i. e. , in different time stages the positive and negative correlations appears alternately, which seems to have some periodicity at a certain extent. Furthermore, there are distinct positive correlations between the SOI, SST in Nino-3 and the δ^18O in precipitation in Hongkong station respectively, showing that the strong signal form ENSO has important impact on the variations of stable isotopes in precipitation at the Zhujiang River Delta.