Study of the moisture content of the troposphere over the ULAB (Ulaanbaatar) monitoring station using GPS measurement, radio sounding and surface meteorology data

Abstract

The water vapor content is calculated in a conditional vertical column to the tropopause level from remote sensing data on the lower atmosphere. The calculations are based on GPS measurements, surface meteorological data and vertical meteorological profiles produced by radiosondes.Atotal zenith tropospheric delay (ZTD) is estimated as a difference between an estimated straight line, along which the GPS signal propagates in vacuum, and alength of the pathbetween the signal source and the receiver, which is refracted in the real medium. A direct correlation is noted between changes in the ‘wet’ component of the tropospheric delay of the GPS signal and variations in the moisture content of the troposphere. A‘wet’ component value of the tropospheric delay can be converted with a very high confidence into a value of integral water vapor above the observation point.In order to determine the integral water vapor amounts over the ULAB (Ulaanbaatar) permanent GPS monitoring station, empirical equations were used for the linear regressions of the ratios of surface temperature and mean weighted temperature for the water vapor elasticity using the data of radiosondes launched in the city of Ulaanbaatar and Murensettlement. We studied the features of the dynamics of variations in the integral water vapor, surface values of atmospheric pressure, air temperature and precipitation volumes over the ULAB station, using the data of July 2016.

Keywords

• gps measurements
• meteorological data
• tropospheric delay of signals
• integral water vapor
• precipitation