ENSO事件对珠江中下游地区降水氢氧同位素的影响  

Influence of ENSO events on the hydrogen and oxygen isotopes of precipitation in the middle and lower reaches of Pearl River

作　　者：郭政昇 郑国璋 曹富强 赵培 肖杰 GUO Zheng-sheng;ZHENG Guo-zhang;CAO Fu-Qiang;ZHAO Pei;XIAO Jie(College of Geographical Sciences,Shanxi Normal University,Linfen 041000,Shanxi,China;College of Environment and Economics,Shanxi University of Finance&Economics,Taiyuan 030006,China;College of Urban,Rural Planning and Architectural Engineering,Shangluo University,Shangluo 726000,Shaanxi,China)

机构地区：[1]山西师范大学地理科学学院,临汾041004 [2]山西财经大学环境经济学院,太原030006 [3]商洛学院城乡规划与建筑工程学院,商洛726000

出　　处：《自然资源学报》2019年第11期2454-2468,共15页Journal of Natural Resources

基　　金：山西师范大学科技开发与应用基金项目(ZK1402);国家自然科学基金项目(41471188)

摘　　要：水汽源区变化与ENSO事件显著影响季风区水循环过程。基于珠江中下游地区4个GNIP站点(中国香港、广州、桂林、柳州)的降水同位素及OLR(向外长波辐射)数据,研究了ENSO背景下δ18O的时空分布特征及ENSO事件对降水中氢氧同位素特征的影响机制。结果表明:ENSO事件是影响稳定同位素年际差异的主要因素,通过影响雨季降水的年内分配而实现;正常年大气降水线方程的斜率与截距均大于厄尔尼诺年而小于拉尼娜年;拉尼娜年加强δ18O的反温度效应,厄尔尼诺年减弱反温度效应;厄尔尼诺与拉尼娜年热带辐合带的变化规律呈现出相反的趋势,其OLR场的变化与研究区稳定同位素特征有着较强的对应关系;ENSO事件年不同的水汽源区相对湿度特征是造成d值年际差异的主要因素。The characteristics of stable isotopes in precipitation are influenced by moisture transport path, rainfall amount, temperature, humidity, elevation and so on. El Ni?o-Southern Oscillation(ENSO) is one of the strongest signals of Global Coupled Ocean-Atmosphere and an important factor influncing the inter-annual climate change. The variation of moisture sources and the ENSO events prominently affect the processes of hydrological cycle and characteristics of precipitation isotope in the East Asian monsoon region. Based on the isotopic values of precipitation and Outgoing Longwave Radiation(OLR) data from four stations of GNIP(Hong Kong, Guangzhou, Guilin, Liuzhou) in the middle and lower reaches of the Pearl River, the spatial distribution and temporal characteristics of δ18 O in precipitation were studied under the background of ENSO. The results show that the ENSO event was the main factor which affected the inter-annual variation of stable isotopes in precipitation in the middle and lower reaches of the Pearl River by impacting the annual distribution of precipitation especially in the rainy season. The slope and intercept of the Meteoric Water Line in normal year were larger than those in El Nino year and smaller than those in La Ni?a year. La Ni?a year highlighted the strong characteristics of marine climate. The δ18 O in precipitation showed antitemperature effect. This phenomenon was strengthened in La Ni?a year and weakened in El Ni?o year. The position of Intertropical Convergence Zone(ITCZ) in moisture sources,intensity of convective activity and the process of air mass migration largely determined the characteristics of stable isotopes. The scope and strength of ITCZ in La Ni?a and El Ni?o years showed the opposite trend. The variation of OLR field had a strong correspondence with the stable isotope characteristics in the study region. There was a significant negative correlation between d-excess and the intensity of ENSO events. The relative humidity characteristic of moisture sources in different EN

关 键 词：稳定同位素 ENSO OLR场 ITCZ 珠江中下游地区 

分 类 号：P73[天文地球—海洋科学]