摘要
基于2012年6~8月的实测水汽同位素数据及相关气象数据,对黑河中游夏季昼夜的同位素基本特征、水汽来源方向及潜在蒸发源地进行了研究。结果表明:空气水汽线斜率白天大于夜晚和水汽过量氘值白天大于夜晚,综合说明白天局地蒸发较夜晚强烈;夏季受西风水汽影响显著。其中,6月主要受西风水汽和北冰洋水汽影响,7、8月主要受西风水汽和东南方向水汽影响,且8月受东南方向水汽影响最为明显;水汽运移路径上下垫面地形和气压带移动会影响水汽后向轨迹高度,西北方向上水汽输送通道较顺畅,风速较大,有利于水汽的输送;水汽蒸发源地主要集中在研究区周围及以东、以北部,其次是西北部。绿洲是主要的水汽蒸发源地,其次是城市和河流,白天较夜晚局地蒸发强烈且面积大。
In this study,we analyzed the basic characteristics of water vapor isotopes in the middle reaches of the Heihe River,Gansu Province,China mainly based on water vapor d data. We used PSCF and CWT analysis for the 2012 summer months in the studied area.We identified potential steam source locations during the day and night,and connected this with backward trajectory clustering,maximum wind speed and direction analysis,atmospheric precipitation data,and vapor flux divergence.Our results showed that the slope of the moisture line in the daytime was greater than that at night,with elevated d values during the day.This suggests that local evaporation is stronger during the day than at night.The values of D and 18O in the water vapor increased every month,and were significantly elevated during the day due to the urban heat island effect.The water vapor source was complex,and the d value of the water vapor decreased throughout the summer.In June,high values reflected relatively humid conditions in the western Pacific,which were significantly affected by arctic and westerly water vapor.In July and August,the arctic vapor was steadily replaced by southeast water vapor.Surface topography and the movement of the pressure zone on the path of water vapor transport both affected the height of the backward trajectory of the water vapor.The water vapor transportation channel in the northwest direction was smooth with high wind speeds,which encourages water vapor transportation.In response to the movement of the pressure belt,the backward trajectory height of water vapor in August was higher than that in June and July.The origins of the water evaporation were mainly concentrated to the east and north of the study area,with lesser contributions from the northwest.Oases were the main source of water evaporation,followed by cities and rivers,with local evaporation being stronger during the day than at night.Indeed,most of the observed features were strengthened by warm daytime temperatures.
作者
孟鸿飞
张明军
王圣杰
邱雪
杜铭霞
张亚宁
余秀秀
周苏娥
MENG Hong-fei;ZHANG Ming-jun;WANG Sheng-jie;QIU Xue;DU Ming-xia;ZHANG Ya-ning;YU Xiu-xiu;ZHOU Su-e(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,Gansu,China;Key Laboratory for Ecology and Environment of River Wetlands in Shaanxi Province,Weinan 714099,Shaanxi,China)
出处
《干旱区地理》
CSCD
北大核心
2020年第2期360-370,共11页
Arid Land Geography
基金
国家自然科学基金(41461003,41771035,41701028)
甘肃省高等学校创新团队项目(2018C-02)资助。
关键词
夏季昼夜
水汽来源
水汽同位素
黑河中游
summer days and nights
water vapor sources
water vapor isotope
middle reaches of Heihe River