中国亚热带大气降水氢氧稳定同位素特征及其影响因素  

Characteristics and Drivers ofδD andδ^(18)O in Precipitation over Subtropical China

作　　者：张蓓蓓 徐庆[1] 高德强 左海军 任冉冉 许文斌 Zhang Beibei;Xu Qing;Gao Deqiang;Zuo Haijun;Ren Ranran;Xu Wenbin(Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration,Ecology and Nature Conservation Institute,Chinese Academy of Forestry,Beijing 100091,China)

机构地区：[1]中国林业科学研究院森林生态环境与自然保护研究所,国家林业和草原局森林生态环境重点实验室,北京100091

出　　处：《陆地生态系统与保护学报》2022年第4期13-20,共8页Terrestrial Ecosystem and Conservation

基　　金：国家自然科学基金(31870716,31670720);林业公益性行业专项(201504423);中央级公益性科研院所基本科研业务费专项资金(CAFYBB2017ZB003)。

摘　　要：【目的】探究中国亚热带地区大气降水氢氧稳定同位素特征可以获取其水汽循环过程及气候信息,为准确预测气候变化背景下大气降水的时空分布格局提供科学依据。【方法】基于数据整合分析方法,从72篇文献中收集了中国亚热带地区78个站点的大气降水氢氧稳定同位素数据,探究该地区大气降水氢氧稳定同位素及过量氘的空间分布特征。利用最小二乘回归分析方法分析大气降水氢氧稳定同位素与有关因素的相关关系,并通过多元线性回归模型揭示影响大气降水氢氧稳定同位素空间分布的主导因素。【结果】研究发现,中国亚热带地区大气降水δD(δ^(18)O)存在西部贫化中东部富集现象,分布范围为−111.19‰~−19.80‰(−15.32‰~−3.74‰)。与之类似,大气降水过量氘同样呈现西低东高的格局,分布范围为−11.27‰~26.55‰。此外,发现大气降水δD(δ^(18)O)与经度(δD:r=0.61,P<0.001;δ^(18)O:r=0.51,P<0.001)呈显著正相关,而与海拔(δD:r=−0.60,P<0.001;δ^(18)O:r=−0.57,P<0.001)呈显著负相关。但多元线性回归分析发现,上述2类因子均不是大气降水δD(δ^(18)O)的主要调控因子,而纬度和年均降水量是影响该地区大气降水δD(δ^(18)O)空间分布的主导因素,二者与大气降水δD(δ^(18)O)呈显著正相关。具体表现为:纬度每增加1°,大气降水δD(δ^(18)O)相应富集2.65‰(0.25‰);年均降水量每增加100 mm,大气降水δD(δ^(18)O)相应富集1.43‰(0.17‰)。【结论】中国亚热带地区大气降水δD(δ^(18)O)呈西部贫化中东部富集的格局。另外,该地区大气降水δD(δ^(18)O)呈现“反纬度效应”和“反降水量效应”,这与经典大气降水同位素理论中的“纬度效应”及“降水量效应”明显不同,表明不同地区大气降水氢氧稳定同位素值的环境效应差异较大,建议今后研究中应加以区分。【Objective】Exploring the hydrogen and oxygen stable isotopes in precipitation could improve our understanding on water vapor cycle and climate characteristics,which may help better predict the temporal and spatial distribution of precipitation in subtropical China under the scenario of climate change.【Method】Here,we conducted meta-analysis usingδD(δ^(18)O)data for precipitation from 78 stations reported by 72 peer-reviewed articles over subtropical China to explore the spatial patterns of theδD,δ^(18)O and d-excess in precipitation in this region.Furthermore,we used the least square method to analyze the relationship between theδD(δ^(18)O)in precipitation and environmental factors,and employed multiple regression model to identify the dominant driver affecting theδD(δ^(18)O)in precipitation over subtropical China.【Result】TheδD(δ^(18)O)in precipitation was depleted in the western regions but enriched in the central and eastern regions in subtropical China,with a range from−111.19‰to−19.80‰(from−15.32‰to−3.74‰).Similarly,the d-excess in precipitation gradually increased from the western regions to the eastern regions,with the value ranging from−11.27‰to 26.55‰.Our results further revealed that theδD(δ^(18)O)in precipitation was positively associated with longitude(δD:r=0.61,P<0.001;δ^(18)O:r=0.51,P<0.001)and negatively correlated with altitude(δD:r=−0.60,P<0.001;δ^(18)O:r=−0.57,P<0.001).However,multiple regression analysis indicated that longitude and altitude were not the primary drivers of theδD(δ^(18)O)in precipitation,while both the latitude and mean annual precipitation were the dominant controls of theδD(δ^(18)O)in precipitation over subtropical China.These two factors have positive effects on theδD(δ^(18)O)in precipitation,with a gradient of 2.65‰(0.25‰)enrichment in theδD(δ^(18)O)per 1°increase in latitude and a gradient of 1.43‰(0.17‰)enrichment in theδD(δ^(18)O)per 100 mm increase in mean annual precipitation.【Conclusion】TheδD(�

关 键 词：大气降水 氢氧稳定同位素 过量氘 中国亚热带 整合分析 

分 类 号：P426.6[天文地球—大气科学及气象学]