Study On The Change Of Tropospheric Water Vapor During Typhoon

The troposphere is the layer closest to the earth's surface and is an important part of the atmosphere.Various climate changes and the occurrence of extreme weather are closely connected with the troposphere.Although water vapor occupies a small proportion in the earth's atmosphere,most of it exists in the troposphere,and water vapor plays an important role in some weather events.The activity of water vapor in the atmosphere is relatively active,and it is difficult to use conventional atmospheric detection methods to carry out its temporal and spatial distribution characteristics.Based on the above content,the main research content of this article is as follows:(1)Briefly introduce the research background,significance and development status of GPS water vapor inversion.The related theories of tropospheric and water vapor inversion are introduced,including several models and mapping functions of tropospheric delay.The principle of inversion of atmospheric precipitable volume with tropospheric delay and airsonde data inversion is briefly described.(2)Using the IGS site tropospheric delay product data provided by the International GNSS Analysis Center,the time and space changes of the ZTD sequence are analyzed.Through the ZTD sequence of more than 200 GNSS stations distributed globally,the global spatial distribution of tropospheric delay is explained,and the law of tropospheric delay changing with latitude and changing with altitude is analyzed.A total of 9 years of ZTD time series from January 2010 to December 2019 in China's regional IGS sites are used to analyze the laws and characteristics of ZTD changes over time.(3)Taking the super typhoon "Mangkhut" that occurred in Hong Kong in September 2018 as an example,analyze the spatial and temporal characteristics of the PWV time series obtained by GNSS inversion,and explore the temporal and spatial characteristics of water vapor over Hong Kong during the typhoon.At the same time,by comparing the correlation between PWV and precipitation,it can be seen that water vapor accumulation is a prerequisite for large amounts of rainfall.When water vapor accumulates to a certain extent,a large amount of rainfall will be generated.At the same time,rainfall is also restricted by various random factors.For example,terrain affects water vapor distribution and rainfall.In addition,the article only studies the two-dimensional distribution of water vapor and analyzes it.The selected GNSS sites are all located on the same side of the typhoon path.If there is enough data to support,the vertical distribution of water vapor can be changed using water vapor tomography technology.The analysis is of great valueFigure[24]table[7]reference[82]...