Analysis of GPS-sensed atmospheric water vapour variability and its response to the terrestrial winds over Antarctica

Recent advances in GPS sensing technology and the availability of low-cost GPS receivers have allowed the continuous measurements of atmospheric water vapour in all weather conditions and on a global scale. This paper aims to analyze the variability of the Antarctic precipitable water vapour (PWV) observed by GPS receivers. In this contribution, the influence of terrestrial winds on the PWV variations is investigated where the climatology is extremely different from that in the Equatorial region. For this purpose, GPS and surface meteorological data for the period of 2003–2005 are analyzed. A significant diurnal variation in PWV was found over most of the sites with PWV difference increasing more than 0.50 mm during summer compared to the winter times on a monthly analysis. Increase in Antarctic PWV evidently follows the variations of the surface temperature. In winter, the temperature increase will be lower by about 1 °C and values of water vapour are 13% smaller than during summer months. The characteristics of Antarctic climate represented by the PWV variation show a seasonal dependence, higher (active) in summer and lower (inactive) in winter. It was found that the large decreases in the monthly mean PWV distribution were accompanied by strong winds above 10 m s−1.