Air temperature sensors calibration in the Arctic, and its impact for climate measurements

The Arctic is an important place for environmental data due to its sensitivity to climate change and its remoteness. The research center of Ny-Ålesund, in the Norwegian Svalbard Archipelago, is a key place to perform such measurements given the infrastructures already available and the relative ease of access. The harsh environment of the polar regions can degrade the performance of sensors, which are not designed to be run in these environments: maintenance of these sensors must be frequent and made with metrological rigour, in order to provide traceability and comparability in time and space with other sensors. This communication reports on the calibration campaign INRiM set out on the air temperature sensors installed on the Ny-Ålesund Climate Change Tower (CCT), managed by CNR-ISP. This campaign was able to correct the temperature measurements of the atmospheric vertical profile from ground to 34 m, and found errors up to 1 °C; moreover it was able to reduce the absolute measurement uncertainty with respect to the one stated by the manufacturer, and the relative uncertainty on the profile to few hundredths of a degree Celsius. Future development will also be illustrated.