【摘要】 根据广州市2004年5月—2005年6月和2007年4月—2008年6月大气降水中δ18O含量及气象数据,分析了广州市大气降水δ18O对极端天气事件的反映.结果表明:研究期间广州市的大气降水δ18O都落在世界降水δ18O的变化范围之内,夏季低冬季高;2004年由于夏季风爆发偏晚且活动位置偏南等因素致使广州降水δ18O与气温正相关;2005年夏季风爆发晚,高纬冷空气偏强,前汛期华南成强降水中心,广州5、6月降水中δ18O偏低;2008年1月华南地区严重的冰灾期间大气降水δ18O波动剧烈,"负温度"效应和降水量效应更加明显;热带气旋使广州市降水δ18O普遍偏低.更多还原

【Abstract】 Based on the oxygen isotope results of precipitation and the meteorological data at Guangzhou from May 2004 to June 2005 and from April 2007 to June 2008,we analyzed the response of precipitation δ18O to the extreme weather events.We concluded that:(1) During the study periods,the magnitudes of precipitation δ18O were within the range of world’s precipitation δ18O and showed lower values in the summer generally;(2) In 2004,the later outbreak of the Summer Monsoon and southward shifting resulted in the extremely summer dry in South China.Our data reflected a positive correlation between rainfall δ18O and temperature;(3) The onset of the Summer Monsoon was later in 2005,besides the stronger high-latitude cold air shifts southward,the South China became the rainfall center at the pre-flood season,precipitation δ18O in Guangzhou appeared lower values in May and June;(4) In January 2008,the freezing disaster in South China was associated with the "North Ridge" but "South Passage" atmospheric circulations,maximum polar vortex area index in Eurasia and the strengthened "La Nina" event.The rainfall δ18O fluctuated heavily and the "Negative temperature effect" and "Precipitation effect" were more obvious;(5) All precipitations δ18O brought by tropical cyclones showed depleted values and varied with the previous typhoons characteristics.更多还原