Atmospheric Composition

In the Satellite Observations Department at KNMI we study the global and regional atmospheric composition using satellite observations of trace gases, aerosols, clouds and winds. The observations contribute to monitoring and research of Climate, Ozone, and Air Quality. The main satellite instruments used in our division are OMI, GOME, GOME2, SCIAMACHY, SEVIRI and ASCAT. We develop calibration and retrieval algorithms for these instruments, and process and distribute the satellite data to users, e.g. via TEMIS, in collaboration with international partners. To validate the satellite observations and to provide local monitoring we also operate several ground-based instruments, like the Brewer, the ozone sonde and the NO2 sonde. Our division has the Principal Investigatorship for the Dutch-Finnish instrument OMI, launched in 2004 on NASA's EOS-Aura satellite, and for the Dutch-ESA instrument TROPOMI, to be launched early in 2016 on ESA's Sentinel-5 Precursor satellite.
A thirty year time series of the ozone hole (left) and a global air pollution map of NO2 (middle). A brochure about our department (right).


2018-03-08: Field calibration of electrochemical NO2 sensors in a citizen science context

We assessed the performance of low-cost air quality sensors which were used to measure air pollution in Amsterdam during the 2016 Urban AirQ campaign. We show that the current generations of electrochemical NO2 sensors may provide useful complementary data on local air quality, provided that the experiment is properly set up and the data are carefully analysed.


2018-02-06: Simultaneous assimilation of ozone profiles from multiple UV-VIS satellite instruments

Ozone profiles measured by two satellite instruments (GOME-2A and OMI) have been combined with a chemical transport model using data assimilation. The results give a better insight into the global spatial and temporal ozone distribution than either measurement or model results alone. Validation with independent measurements shows biases varying between -5% and +10% between the surface and 100 hPa, while between 100 and 10 hPa the biases vary between -3% and +3%.


2017-10-24: Antarctic Ozone Hole decreased by 20%

The Antarctic Ozone Hole that forms over Antarctica ever year during springtime is continuing to heal. Since about the year 2000 its ozone depletion has decreased by approximately 20%. Likely this is mostly due to international agreements on the protection of the ozone layer. Such are the findings of a recently published new research paper by KNMI. First signs of global recovery of the ozone layer had already been reported before.


All news items