Establishment and preliminary results of an atmospheric precipitable water vapor measurement system at Ali site in Tibet

To better understand the characteristics of atmospheric precipitable water vapor (PWV) in high-altitude regions, we have installed a microwave radiometer at the Ali site in Tibet for PWV measurements. The calibrated microwave radiometer is operating normally. Currently, it is the summer season at this site, and the PWV distribution ranges from 6 to 14 millimeters. In addition to measuring in the zenith direction, the microwave radiometer can also perform rotational scanning to obtain numerical results of PWV distribution throughout all the sky above the site. Besides the measurement of Precipitable Water Vapor, we have also published profile measurements of relative and absolute humidity. With the continuous measurement and accumulation of data on PWV, it will provide important support for the upcoming primordial gravitational wave measurement experiments.