Temperature climatology for Schiphol (the Netherlands), for present-day and climate scenarios in 2050

Temperature is an important climatological variable at Schiphol Airport (Amsterdam, the Netherlands), for many aspects of daily operations as well as for longer-term planning. Mostly due to anthropogenic global warming, temperature at Schiphol Airport has been rising over the past decades and is projected to continue to rise over the 21st century. In this report, a climatology of daily, monthly and annual minimum and maximum temperature is derived from observations at Schiphol Airport in the period 1981-2010. This was done for the present-day climate as well as projected into the future, according to the KNMI’06 Climate Scenarios for the Netherlands. These scenarios incorporate different estimates of the increase of the mean temperature and the change of its variance, into the 21st century.

For the present-day climate we have considered the average daily minimum and maximum temperature for different parts of the year (months and decades of days). We have also looked at the average number of days per month and per year on which certain thresholds for minimum and maximum temperature are exceeded.

Furthermore, for the present-day climate we have carried out an analysis of the occurrence of extreme monthly and annual minimum and maximum temperatures. In this analysis GEV statistical distributions were fitted on observed extremes. In the derivation of the GEV shape parameter, we have pooled together observations from different months in the year. It was derived that for monthly minimum temperatures one negative value of the GEV shape parameter could be used for April through November, and value 0 (resulting in Gumbel distributions) for December through March. For monthly maximum temperatures one value of the GEV shape parameter could be applied for all calender months. From the fitted distributions, return values of monthly and annual minimum and maximum temperatures were derived for return periods of up to 50 years.

The observed time series of daily minimum and
maximum were then transformed, applying changes to their statistical distribution according to four climate scenarios, for time horizons 2010 and 2050. All above-described analyses were repeated for these transformed time series, obtaining projected future climatologies of minimum and maximum temperature. The statistics for the time horizon of 2010 can be used to estimate how much, according to the scenarios, the climate may have already changed since the 1981-2010 normal period, which may be most representative for its central year 1995.