Quantifying Surface Temperature Inversions and Their Impact on the Ground Thermal Regime at a High Arctic Site

ABSTRACT Air and ground temperature data collected at Canadian Forces Station Alert, Nunavut, Canada, have been analyzed to investigate the potential role that air temperature inversions play in influencing the spatial variation of permafrost thermal conditions in coastal areas of the High Arctic. Frequent, persistent air temperature inversions have been documented using a series of weather stations deployed along an elevation gradient inland from the coast. During inversion periods, which may last several days, air temperatures in valley bottoms can be up to 10 °C lower than adjacent stations located at elevations 47 to 130 m higher. The occurrence of air temperature inversions during the winter combined with thin snow cover suggest a mechanism explaining the observation of lower winter ground-surface temperatures and colder permafrost conditions in valley bottoms compared to higher elevations.