Project

Measuring the emissions of greenhouse gases

Greenhouse gases move through the atmosphere.

Innovative atmospheric measurements and model calculations are required to be able to establish the level of emissions in each area.

Scintillometers measure the exchange of heat and water vapour between the earth’s surface and the atmosphere, also known as the surface fluxes of heat and water vapour. Using ceilometers, researchers establish the thickness of the turbulent layer in the atmosphere (the so-called boundary layer). The researchers combine these measurements with model calculations and thus gain an increased understanding of the behaviour of the turbulent atmosphere and the way in which greenhouse gases move in the atmosphere.

Scintillometer

In some places in the Netherlands, measurements have been performed since 1999, which means that extensive data are available. When collating and analysing the data, the Environmental Sciences Group of Wageningen UR works jointly with the KNMI (The Royal Netherlands Meteorological Institute). The results are also useful to other research projects and are also used in the education and research of the Meteorology and Air Quality chair group. For the study, this chair group developed the Large Aperture Scintillometer (LAS), the first measuring instrument that can measure the surface flux across distances of up to ten kilometres. The scintillometer looks at the fluctuations in intensity (called scintillations) of infrared light or radio waves that are caused by the atmosphere. The transmitter sends a beam of light to the receiver. The beam of light is distorted in the atmosphere. The higher the level of turbulence, the more distortion there is.

Climate summit

The measurements and model calculations enable monitoring of the greenhouse gas emissions caused by human activities. That is important because during the climate summit in Kyoto it was agreed that by 2012 there will be eight percent less greenhouse gas emissions than in 1990. The Netherlands has committed to reducing the emissions by six percent by 2012.