The present installation of a planned 100 stations in the United States Climate Reference Network (USCRN) has added a wealth of information concerning not only the elemental relationships between wind, solar radiation, infra-red surface (skin) temperature, and ambient temperature, but also the spatial comparison of ambient temperatures sensed in three separate aspirated shields. The USCRN sensor suites monitor the sensed ambient temperatures in each shield as well as the speed of the aspirating fans in each shield. Currently existing quality control checks for both the departure of the sensed temperature (between the three shields) and the speed of the aspirating fans has allowed the quality control staff to quickly alert maintenance personnel when either condition exceeds the quality control limits in magnitude and or time. In those few cases where either the temperature sensor or fan have exceeded the limits, the readings from the other two redundant sensors and their associated fans provide a solid reference from which we are able to document the magnitude and timing of the failure of the suspect sensor.

This report will document several types of failures and their causes as well as cases of what otherwise might appear to be failures but are actually real differences in terrestrial heat flux on a small spatial and temporal extent.