Site-testing at Muztagh-ata site I: ground meteorology and sky brightness

Site-testing is crucial for achieving the goal of scientific research and analysis of meteorological and optical observing conditions, one of the associated basic tasks. As one of three potential sites to host the 12-meter Large Optical/infrared Telescope (LOT), the Muztagh-ata site, which is located on the Pamir Plateau in Xinjiang, in west China, began its site-testing task in the spring of 2017. In this paper, we firstly start with an introduction to the site and then present a statistical analysis of the ground-level meteorological properties such as air temperature, barometric pressure, relative humidity, and wind speed and direction, recorded by an automatic weather station with standard meteorological sensors for a two-year duration. We also show the monitoring results of sky brightness during this period.