Comparative Study on the Sources of Precipitation Water Vapor in the Shaliu River Basin of Qinghai Lake in Abnormal Climate Years

Abstract

Climate change profoundly affects the water budget and the water vapor cycle， and studying the source of water vapor under abnormal climate conditions is of great significance to the study of the regional water cycle.It is well known that the year 2017 and 2019 are La Niña and El Niño years， respectively.Therefore， GDAS （Global Data System） meteorological data of January， April， July and September in 2017 and 2019 are used to better study the sources of precipitation and water vapor in climate abnormal years， the data comes from the National Environmental Forecast Center of the National Oceanic and Atmospheric Administration （NOAA）.Existing studies have shown that the HYSPLIT Lagrangian model is widely used not only in the study of atmospheric pollution sources but also in the study of meteorological and precipitation water vapor sources.Therefore， this study uses the HYSPLIT Lagrangian model to compare the sources of precipitation and water vapor in the Shaliu river basin of Qinghai Lake in the year of abnormal climate.The comparative study is expected to provide theoretical reference for the study of the water cycle in the basin.The results showed that： （1） the water vapor source of precipitation in the Shaliu river basin of Qinghai Lake in 2017 and 2019 was mainly westward water vapor transport before April.After April， the source of water vapor began to gradually carry eastward transportation.Until September， the water vapor transportation in the basin gradually weakened from the east direction， and the water vapor transportation gradually increased in the west direction.（2） Compared with the sources of water vapor in the Shaliu river basin of Qinghai Lake in 2017 and 2019， the source of water vapor in the north direction of the Shaliu river basin in 2019 was earlier than that in 2017.The westward water vapor transportation shifted to the eastward water vapor transportation earlier， in 2017， the Shaliu river basin was affected by the westward water vapor transportation for a long time， and the transportation path was single.（3） The La Niña occurrence period in 2017 intensified the intensity of water vapor transportation in the west direction of the Shaliu river basin and shortened the time of water vapor transportation in the east direction； the occurrence of El Niño in 2019 weakened the intensity of water vapor transport in the westward direction in the basin， increased the northward water vapor transport path， and extended the eastward water vapor transport time.

Keywords

• qinghai lake
• abnormal climate
• shaliu river basin
• source of water vapor