In the Climate Observations division we study the global and regional
atmospheric composition using satellite observations of trace gases, aerosols
and clouds. 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 and SEVIRI. 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 in 2014/15 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 (right).
2013-11-04: OMI - News: Antarctic Ozone Hole in 2013
According NASA's Ozone Hole Watch team and based upon a combination of ozone column data from OMI and from the Ozone Monitoring and Profiler Suite (OMPS) on the NASA-NOAA Suomi NPP satellite, the ozone hole over Antarctica was slightly smaller in 2013 than the average for recent decades. The combined set of satellite data showed an the average size of the hole in September-October 2013 of 21.0 million square kilometers. The average size since the mid 1990s is 22.5 million square kilometers.Read more...
2013-10-29: Retrieval of aerosols using the oxygen A band in the presence of vegetation fluorescence
Within ESA's Sentinel-5 Precursor / TROPOMI project researchers at KNMI are currently developing a new operational aerosol product that is specifically dedicated to retrieval of the height of tropospheric aerosols. Aerosol height information will contribute to ash-forecasting systems for aviation safety and it will improve our understanding of aerosol interactions in climate research. The aerosol layer height product is based on the oxygen A band in the near-infrared wavelength range. In the same wavelength region vegetation exhibits fluorescence emissions as a byproduct of photosynthesis. Studies shows that aerosol retrieval may be inaccurate if fluorescene emissions are not taken into account. In a recently published article we have investigated how vegetation fluorescence should be treated in an O2 A band aerosol retrieval algorithm.Read more...
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2013-09-30: Inter-calibration of polar imager solar channels using SEVIRI
Accurate calibration of satellite imagers is a prerequisite for using their measurements in climate applications. We have developed a method for the inter-calibration of geostationary and polar-orbiting imager solar channels based on regressions of collocated near-nadir reflectances.Read more...