Site-testing at Muztagh-ata site. IV. Precipitable Water Vapor

This is the fourth article in a series studying on the site-testing at Muztagh-ata site. The results of the characterization of precipitable water vapor (PWV) in the atmospheric column at Muztagh-ata site are presented. This paper studies the temporal variability of PWV, acquired from remote sensing data sets and validated by limited radiometers data, spanning a period from 2018 to 2019. The clear day PWV annual median values are 2.28 mm and 2.37 mm for 2018 and 2019 respectively. The results show that the driest seasons at Muztagh-ata site are from October to March and there are about 60 similar to 70 days with daily median PWV less than 2 mm in this period. Atmospheric transmission in mid-infrared bands calculated by AM model confirms the IR observation potential of Muztagh-ata site.