The annual cycle of temperature in Iceland

Abstract

This report presents the results of an analysis of temperature at weather stations in Iceland. Monthly temperature means for the period 1961 – 1990 were calculated for each station, and the results spatially interpolated.

The spatial interpolation procedure consisted of two steps: de-trending and kriging. In the de-trending step an 8 component linear model was fitted to the temperature data, and the residual from the linear model calculated. In the kriging step, the residuals were spatially interpolated to a map of Iceland using kriging. The results from the linear model were added to the interpolated residual field to produce a map of mean temperature for the month. This method was employed for the 12 calendar months, and also for the annual mean.

Following this, the 12 monthly values at each gridpoint of the map were interpolated to produce a 365 day smooth seasonal cycle. This allowed for a more detailed study of the annual cycle and the calculation of maps of various temperature related indices.