The analysis of water vapor distribution over Taklimakan Desert

Up to now, all analysis of the distribution of water vapor over the Taklimakan desert area only depends on limited ground measurements and radio soundings setting mostly on the outer margin area. This paper establishes an approach to retrieve the water vapor over the desert at high temporal and spatial resolutions by the use of FY2C geostationary satellite split-window channels in cooperation with ground-based GPS water vapor measurement. Results show that the water vapor distribution over the Taklimakan desert is affected highly by topography and surface properties. The outer margin area has generally more water vapor than the inner area. Over the outer margin area, the western part has more water vapor than the eastern part, and the northern part has more than the southern part. The driest area lies to the south of Tazhong, east of Hotan River, and extended to the south boundary of the desert. Similar to elsewhere, water vapor over the desert area shows diurnal, monthly, seasonal and annual variations even at the driest inner area of the desert. In summer, the water vapor is transported from west to east over a long distance along the westerlies at a height between 700–400 hPa and with the average speed of 50 km h−1.