WC Archive

The European Space Agency has been involved in some very cool projects lately. Now comes word that the ESA "Envisat" -- the largest Earth Observation satellite ever built -- has just completed 18 months of observations of Nitrogen Dioxide accumulation. Using its "Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY)," it has produced the most detailed map yet of global atmospheric pollution.

"The higher spatial resolution delivered by SCIAMACHY means we see a lot of detail in these global images, even resolving individual city sources" said Steffen Beirle of the University of Heidelberg's Institute for Environmental Physics, responsible for the map shown above.

"High vertical column distributions of nitrogen dioxide are associated with major cities across North America and Europe, along with other sites such as Mexico City in Central America and South African coal-fired power plants located close together in the eastern Highveld plateau of that country.

"Then a very high concentration is found above north eastern China. Also across South East Asia and much of Africa can be seen nitrogen dioxide produced by biomass burning. Ship tracks are visible in some locations: look at the Red Sea and the Indian Ocean between the southern tip of India and Indonesia. The smoke stacks of ships crossing these routes send a large amount of NO2 into the troposphere.

This map is average out across all available data, spanning 18 months. This has the effects of reducing seasonal variations in biomass burning and also those due to human activity changes due to the time of year."

NO2 is a major component of smog, triggering the development of tropospheric ozone. The map shown above is a small version of a massive (1.6 MB jpeg, 7.8 MB TIFF) display of NO2 density observed between January 2003 and June 2004. I have to say, the image makes an impressive, if disturbing, computer desktop.