北京连续降水水汽输送差异的同位素示踪  

Using stable isotopes to study vapor transport of continuous precipitation in Beijing

作　　者：宋献方[1,2] 唐瑜[1,3] 张应华[1] 马英[1] 韩冬梅[1,2] 卜红梅[1] 杨丽虎[1] 刘飞[1] 

机构地区：[1]中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室,北京100101 [2]中国科学院大学资源与环境学院,北京100049 [3]中国科学院大学中丹学院,北京100190

出　　处：《水科学进展》2017年第4期488-495,共8页Advances in Water Science

基　　金：中国科学院地理科学与资源研究所"一三五"战略科技计划项目(2012ZD003)

摘　　要：为了探讨连续降水过程中水汽输送的变化,应用NCEP/NCAR资料、HYSPLIT后向轨迹模拟及降水稳定同位素资料对北京22场连续降水的水汽输送差异进行了研究。结果表明:连续降水的水汽输送可分为西向水汽输送、远洋水汽输送、近海水汽输送、远源大陆水汽输送和局地大陆水汽输送5种类型,并以近海水汽输送和西向水汽输送为主(降水量占比60.8%)。不同水汽输送类型下降水δ^(18)O的差异主要受水汽源区同位素富集程度及水汽输送途中降水过程的影响,降水氘盈余的变化反映出二次蒸发的影响及水汽源区大气相对湿度的差异。14场连续降水的水汽输送类型发生了变化,且降水δ^(18)O值的变化能够较好地指示水汽输送类型的变化。该结果说明降水同位素特征能够为识别水汽输送类型提供有效信息。To study changes in water vapor transport during continuous precipitation,stable isotope data,NCEP/NCAR data and Hybrid Single Particle Lagrangian Integrated Trajectory（ HYSPLIT） backward trajectory results during 22 continuous precipitation events in Beijing are analyzed. The results indicate that there are five different vapor transport types for the 22 continuous precipitations： westerly vapor transport,remote oceanic vapor transport,vicinal oceanic vapor transport,remote continental vapor transport,and vicinal continental vapor transport. Vicinal oceanic vapor transport and westerly vapor transport are predominate vapor transport types,contributing to 60. 8% of the total precipitation. Variations of precipitation δ^（18）O signals in different vapor transport types are mainly caused by differences in isotopic components in the source regions and the upstream rainout processes along the vapor transport pathways.Changes in deuterium excess reveal the influence of re-evaporation during precipitation and the humidity conditions in the vapor source areas. Fourteen continuous precipitation events are controlled by different vapor transport types at different stages,and the variations in precipitation δ^（18）O indicate the changes in vapor transport types. These results show that isotope signals in precipitation can provide useful information for identifying vapor transport types.

关 键 词：降水 水汽输送 同位素 HYSPLIT模型 北京 

分 类 号：P426.61[天文地球—大气科学及气象学]