华北地区大气降水稳定同位素特征与水汽来源

选取华北地区的包头,石家庄,天津,太原IAEA/WMO/GNIP大气降水的氢氧同位素组成的资料,分析了华北地区降水稳定同位素的时空分布特征及其影响因素.研究表明:华北地区降水中的δ18O值都表现出明显的“夏高冬低”的季风气候特征,夏季表现雨量效应,冬季温度效应明显；华北各地区降水线方程与全国及全球降水线相比,斜率和截距都偏小,揭示了华北地区降水是在非瑞利条件下进行的,并且除天津外,其他地区稳定同位素特征还受到降水过程中局地水汽循环的影响；d值总体表现出冬高夏低的季节变化特征,说明了冬季风和夏季风期间降水的水源区蒸发条件不同.

Sources and Stable Isotope Characteristics of Precipitation in North China

Hydrogen(H) and Oxygen(O) stable isotope data of precipitation water in the north China area,which were collected at Baotou,Tianjin,Shijiazhuang and Taiyuan by IAEA/WMO/GNIP,were compiled to analyze their temporal and spatial variations and to trace their controlling factors.The results indicate that,the values of δ18O in north China precipitation are high in the half year of summer and low in the half year of winter,showing the significant monsoon climate precipitation characteristics of presenting precipitation amount effect during the half year of summer while presenting temperature effect during the half year of winter.The observed slopes and the intercepts of meteoric water lines in this study are smaller than those of averaged meteoric water lines for overall China or the world indicates that isotope fractionations in north China precipitation does not follow the Raleigh fractionation;the values of deuterium are high in the half year of winter and low in the half year of summer,this seasonal characteristics implies different evaporation conditions at their vapor sources.