Analysis Of Water Vapor Sources In Shijiazhuang And Its Influence On Composition Characteristics Of ?¹⁸O

By analyzing the hydrogen and oxygen stable isotopes in the region and their correlation with meteorological elements,we can better understand the regional climate characteristics and laws;study the characteristics of water vapor transport in the monsoon region and its relationship with precipitation,which is useful for understanding the water cycle and predicting drought and desertification.has very important practical significance.This paper is based on the precipitation isotope data of Shijiazhuang City,Hebei Province,China from2015 to 2018,and the GDAS reanalysis grid data of the National Center for Environmental Prediction(NCEP)Global Data Assimilation System(GDAS)during the same period.(NCEP/NCAR)provides global reanalysis data,and uses Meteo Info software and its trajectory analysis plug-in to analyze the stable isotope characteristics of atmospheric precipitation in the region,simulate the water vapor source and migration trajectory of precipitation from 2015 to 2018,and determine different seasons and trends.Sources of water vapor in the study area in different years.On this basis,combined with the precipitation stable oxygen isotope characteristics of typical precipitation events,the corresponding relationship between the source of water vapor and the stable oxygen isotope in precipitation was discussed.The main results are as follows:(1)The mean value of?¹⁸O in the precipitation in 2015 in the study area was the lowest in four years,and the mean value of?¹⁸O in the precipitation in 2018 was the highest.In general,the average value of stable oxygen isotopes in precipitation in the summer half year in the study area is higher than that in the winter half year,and the variation range is smaller.(2)On the annual scale and on the scale of all precipitation events from 2015 to 2018 in the study area,?¹⁸O in precipitation has a certain correlation with temperature,showing a temperature effect.There is a certain correlation with precipitation,showing the effect of precipitation.(3)There are six water vapor source areas in the study area,namely,the water vapor source area of the western Pacific Ocean-the eastern coastal waters of my country,the western Pacific Ocean-the water vapor source area of the South my country Sea,the Indian Peninsula-the water vapor source area of the Bay of Bengal,and the water vapor source area of the northern Eurasian continent,the high-altitude and far-source water vapor area in the west,and local evaporation.Differences in water vapor sources in different seasons.At the same time,the water vapor sources and migration paths of precipitation at different heights are different:at the 500m and 1500m heights,the water vapor in winter mainly comes from the cold air mass moving south from Siberia-Mongolia and local evaporation,and in summer the water vapor mainly comes from the South China Sea and the western Pacific Ocean;the3000m height The water vapor of the upper layer in winter mainly comes from the north-south branches of the high-altitude westerly belt,and the water vapor in summer mainly comes from the warm and humid water vapor from the southwest under the influence of the Indian monsoon.(4)The isotopic characteristics of precipitation in the study area from 2015 to 2018 are closely related to the monsoon circulation.In the winter half year,the precipitation water vapor sources in the study area mainly include the northern water vapor source area and the western high-altitude remote water vapor area.At this time,the?^l8O in the precipitation in the study area has a temperature effect.The source of water vapor,the water vapor source of the Western Pacific Ocean-South my country Sea,and the water vapor source of the Indian Peninsula-Bay of Bengal,the?l8O in the precipitation has a precipitation effect at this time,and the precipitation isotope and the water vapor source under the influence of the summer monsoon have a certain law:summer In the early stage of wind influence,when the precipitation came from land,the isotope ratio in the precipitation was slightly higher.With the advance of the summer monsoon,the precipitation trajectory from the ocean increased,and the isotope ratio in the precipitation also decreased.