High-Resolution Estimation of Summer Surface Air Temperature in the Canadian Arctic Archipelago

Abstract

In the Canadian high Arctic patterns of temperature are poorly resolved at the mesoscale. This issue is addressed using a model to estimate mean summer surface air temperature at high spatial resolution. The effects on temperature of site elevation and coastal proximity were selected for parameterization. The spatial basis is a 1-km resolution digital elevation model of the region. Lapse rates and resultant wind estimates were obtained from upper-air ascents. These were used to estimate the change in temperature with elevation based on the digital elevation model. Advection effects are handled using resultant winds, air temperature above the ocean, and distance to coast. Model results for 14-day runs were compared to observed data. The two effects captured much of the mesoscale variability of the Arctic climate, as shown by verification with point observational data. Sensitivity analyses were performed on the model to determine response to alterations in lapse rate calculation, sea surface temperature, and wind field generation. The model was most sensitive to the lapse rate calculation. The best results were obtained using a moderate lapse rate calculation, moderate wind field, and variable sea surface temperature.