The KNMI has moved part of the weather station at Groningen Airport Eelde by 35 meters. This happened partly due to recommendations from RTV Drenthe weathermen Hans Nienhuis and Roland van der Zwaag and after extensive KNMI research into the influence of the solar park that was installed next to the station in 2019.
According to Roland van der Zwaag, the deviations have been visible for a long time. “The sensors of the measuring station are located in a hole,” he says. “As a result, it remains cold for longer in cold weather and warm for longer in warm weather. Fog is also less likely to enter the pit.”
In addition, the airport, the solar park and surrounding companies influence the temperature. “On an annual basis, this results in an average deviation of 0.2 to 0.3 degrees,” says Van der Zwaag.
Parallel measurement provides clarity
After the weathermen reported their concerns, the KNMI got to work. “We reported it to the KNMI and they really took it seriously,” Van der Zwaag emphasizes.
In 2020, the KNMI installed a parallel setup on the other side of the runway. This shows that the solar park increases the annual average maximum temperature by 0.1°C and reduces the minimum temperature by about 0.3°C.
Displacement of 35 meters
Based on the research, it was decided to move the temperature and humidity setup 35 meters further south. Measurements have been taken there since November 11.
Van der Zwaag understands the choice, although he sees even better possibilities: “This place meets the WMO standards, but an area such as Nieuw-Beerta between the fields is actually much better. This could also be possible in Eelde if you make agreements with a farmer.”
According to Van der Zwaag, a larger move should not be unthinkable. “At the national station in De Bilt it was also completely moved and everything was then recalculated. That is a huge operation, but it is possible.”
Yet he understands that the KNMI is now opting for a limited step. “It is also an old station and it has been a measuring series of more than 100 years, so you would have to adjust that. In addition, you must be able to maintain it, such as the grass minimum. For now this is a logical choice.”