Impact of the weighted mean temperature on the estimation of GPS precipitable water vapor

The relationship of the weighted mean temperature and the surface temperature was obtained using the radiosonde observation in Anqing from 2004 to 2007. The weighted mean temperature estimated from the regressed formula is higher than that from the Bevis formula when the surface temperature increases, which introduces the difference of approximate 1.9% of the GPS precipitable water vapor when the surface temperature gets to 40degC, and smaller difference in the lower surface temperature. The different regressions between different years induce the difference of 0.72% of the GPS PWV when the surface temperature reaches 40degC, and the difference of 2.17% of the GPS PWV in the surface temperature of -10degC. It suggests that the regressed formula to estimate the weighted mean temperature will be beneficial for the estimation of the GPS PWV in the summer, while it has little positive impact on the estimation in the winter.