"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."
Like GOME, SCIAMACHY works by observing atmosphere-scattered ultraviolet, visible and near-infrared radiation. The hard work comes on the ground, where researchers attempt to retrieve very weak trace gas absorption patterns within the overall spectrum of backscattered light, a feat comparable to finding a needle in a haystack.
The method they use is called Differential Optical Absorption Spectroscopy (DOAS), which is basically a complex filtering process also used with ground-based air-sampling instruments. DOAS removes t
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Contact: Mariangela D'Acunto
mariangela.d'acunto@esa.int
39-069-418-0856
European Space Agency
11-Oct-2004