title: [Characteristics of Stable Isotopes in Precipitation and Their Moisture Sources in Mengzi Region, Southern Yunnan].
abstract: The δD and δ¹⁸O values in precpitation have disciplinary variations, and they have close connections with meteorological parameters and moisture sources. Based on the continuously collected precipitation samples in Mengzi from Jan. 2009 to Dec. 2011, the reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centre for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR), and the Hybrid Single-Particle Lagrangian Integrated Trajectory for 4.8 (HYSPLIT_4.8) model, we analyzed the variations of δD and δ¹⁸O in precipitation at synoptic scale in Mengzi, and the relations between δ¹⁸O in precipitation and air temperature, δ¹⁸O in precipitation and amount, δ¹⁸O in precipitation and wind speed, δ¹⁸O in precipitation and moisture sources. The results showed that the variations of δD and δ¹⁸O values in precipitation exhibited remarkable seasonal variability. The stable isotopic values in precipitation were higher during dry season than those during wet season. The relations between δ¹⁸O in precipitation and air temperature, δ¹⁸O in precipitation and amount indicated significant negative correlations. However, it exhibited significant positive correlation between precipitation δ¹⁸O and wind speed at different pressure levels (300 hPa, 500 hPa, 700 hPa, and 800 hPa), and this result indicated that the wind speed was an important influencing factor for the variations of precipitation δ¹⁸O. With the increasing rainfall levels, the intercept and slope of meteoric water line also increased, and this phenomenon suggested that there was a secondary evaporation effect under sub-cloud in stable isotopes of precipitation. The backward trajectory model showed that the main moisture sources during dry season came from the westerly and the inland. However, during wet season, the remote ocean vapor was the main moisture source in Mengzi, and the δ¹⁸O values in precipitation were much lower during typhoon period.
authors.forename: Guang
authors.initials: G
authors.lastname: Li
authors.forename: Xin-ping
authors.initials: XP
authors.lastname: Zhang
authors.forename: You-peng
authors.initials: YP
authors.lastname: Xu
authors.forename: Song
authors.initials: S
authors.lastname: Song
authors.forename: Yue-feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Xiao-min
authors.initials: XM
authors.lastname: Ji
authors.forename: Jie
authors.initials: J
authors.lastname: Xiang
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
mesh_terms: D002681:China; D004784:Environmental Monitoring; D010103:Oxygen Isotopes / Q000032:analysis*; D011891:Rain / Q000737:chemistry*; D012621:Seasons; D013696:Temperature; D014887:Weather; D014919:Wind
chemical_list: D010103:Oxygen Isotopes