Daily on-line measurements by OMI of tropospheric NO2 above Europe
Tuesday, 18 October 2005.
Since Tuesday 18 October everyone can check today's measurements of air pollution by nitrogen dioxide. Tropospheric NO2 amounts derived from measurements of the satellite instrument OMI (Ozone Monitoring Instrument) are available on the KNMI web site within three hours after the observation.
OMI is one of four instruments on-board NASA's EOS-Aura satellite, launched in July 2004. The aim of the Aura satellite is to observe atmospheric chemistry, and specifically to monitor the ozone layer, the Earth's climate and air pollution. OMI measures ozone and several other trace gases. One of them is nitrogen dioxide (NO2), which, together with aerosol (fine dust particles) and ozone, is one of the most important contributors to air pollution. This nitrogen dioxide can be monitored worldwide on a daily basis and at a city size scale, thanks to OMI's wide observing beam and small pixels.
Ozone measurements are available since April 2005. Measurements of nitrogen dioxide in the lower part of atmosphere (the troposphere) are now also on-line available. The near-real time images for Europe are available on-line between 16:00 and 18:00 hours Central European Time. OMI usually passes over Europe twice a day, around 14:00 and 15:30 hours (CET) and it takes about two and half hour before the data has been broadcasted to the surface, processed and put on-line.
The figures below show the changes in tropospheric nitrogen dioxide
for six consecutive days. It can be clearly seen that on Sunday
afternoon the nitrogen dioxide pollution level is much lower than
the other days.
Click on a figure for an enlargement
Blue: low amounts of nitrogen dioxide,
Grey: no measurements because the view was blocked by clouds,
Red: much higher amounts of nitrogen dioxide.
',
'Tropospheric NO2 above Europe on Thursday 13 October 2005,
as measured by OMI'
) "95 kb - Tropospheric NO2 above Europe on Thursday 13 October 2005")
',
'Tropospheric NO2 above Europe on Friday 14 October 2005,
as measured by OMI'
) "101 kb - Tropospheric NO2 above Europe on Friday 14 October 2005")
',
'Tropospheric NO2 above Europe on Saturday 15 October 2005,
as measured by OMI'
) "114 kb - Tropospheric NO2 above Europe on Saturday 15 October 2005")
',
'Tropospheric NO2 above Europe on Sunday 16 October 2005,
as measured by OMI'
) "103 kb - Tropospheric NO2 above Europe on Sunday 16 October 2005")
',
'Tropospheric NO2 above Europe on Monday 17 October 2005,
as measured by OMI'
) "84 kb - Tropospheric NO2 above Europe on Monday 17 October 2005")
',
'Tropospheric NO2 above Europe on Tuesday 18 October 2005,
as measured by OMI'
) "103 kb - Tropospheric NO2 above Europe on Tuesday 18 October 2005")
Air quality
For a further understanding of the production and spread of air pollution, it is best to combine the OMI measurements with measurements from a ground network and with an atmospheric chemistry model. In The Netherlands, KNMI is currently co-operating with the National Institute of Public Health and the Environment (RIVM) to set up an improved air quality forecasts system for the Netherlands, which combines air quality models, satellite measurements and RIVM's ground measurements.
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