The characteristics and preliminary quality control of soil moisture and temperature observations at US Climate Reference Network sites

The United States Climate Reference Network (USCRN) has over 100 stations established over the United States. Until recently, those stations had only observations in the atmosphere, most importantly temperature and precipitation. After more than a year of observations at the ATDD in Oakridge, TN, and input from soil scientists and the meteorological community, it was decided how soil moisture and temperature sensors would be installed at the USCRN sites. Soil moisture and temperature sensors are installed at each site in three nearby holes at 5, 10, 20, 50, and 100 cm depths. There are now six months of observations at many USCRN sites and this paper considers the characteristics of those measurements and the development of methods of automated quality control.