Stable Isotope Characteristics and Water Vapor Sources of Atmospheric Precipitation in Baotianman,Henan Province
[Objective]It is critical to explore the stable isotope characteristics and water vapor sources of atmospheric precipitation in Baotianman,Henan Province,warm temperate-northern subtropical transition zone in China,which could provide scientific basis for predicting the temporal and spatial distribution pattern of precipitation in climatic transition zone.[Method]We determined the δD and δ18O in 128 precipitation events from May 2021 to April 2023(2 hydrological years)in Baotianman area.To analyze the factors affecting the δD and δ18O in precipitation,we established the relationships of δD(δ18O)and meteorological factors such as rainfall,air temperature and relative humidity by Pearson correlation analysis.We employed the Hybrid Single Particle Lagrangian Integrated Trajectory Model(HYSPLIT)to simulate the water vapor source of atmospheric air mass.[Result]The local meteoric water line in Baotianman was δD=7.86 δ18O+12.29(n=128,R2=0.96,P＜0.05).Its slope was lower than that of the global meteoric water line.The δD(δ18O)and d-excess of precipitation in Baotianman area showed obvious seasonal variation,with a trend of being lower during the growing season and higher during the non-growing season.The source of precipitation in this area also exhibited seasonal changes.The water vapor in the non-growing season came from the southwest monsoon airflow in India,the mid-latitude westerly airflow and local water vapor evaporation,while the water vapor in the growing season stemmed from the South China Sea airflow in the Indochina Peninsula and the mid-latitude westerly airflow.8D(δ18O)of precipitation in Baotianman area were significant negatively correlated with precipitation on the annual scale,indicating a precipitation effect.In addition,on the annual scale,d-excess had a significant negative correlation with sunshine time,air temperature,water vapor pressure,total solar radiation and photosynthetic active radiation,while it had a significant positive correlation with atmospheric pressure.[Conclusion]The seasonal and height changes of water vapor sources indirectly affect the 8D(δ18O)of precipitation by impacting rainfall,whereas local environmental factors directly affect the δD(δ18O)of precipitation.This study supplemented the data of δD(δ18O)in precipitation in Baotianman area,and provided a scientific basis for exploring the water cycle process of Baotianman forest ecosystem.
atmospheric precipitationhydrogen and oxygen stable isotopesBaotianman in Henan Provincewater vapor source
万方数据
维普
