"While nitrogen dioxide vertical column concentrations above central and eastern Europe and parts of the East Coast of the United States have been either static or exhibiting a small decrease, there is a clear and significant increase over China," explains John Burrows of the University of Bremen's Institute of Environmental Physics, SCIAMACHY's Principal Investigator.
"Before SCIAMACHY was flying we previously retrieved NO2 data from its precursor instrument, GOME on ESA's ERS-2 mission. Although GOME had lower resolution, the article shows that China's nitrogen dioxide retrievals from the two instruments overlap seamlessly.
"What the combined data show are that nitrogen dioxide levels have risen by around 50% since 1996, and this behaviour is continuing."
Space-based sensors are the only way to carry out effective global and regional monitoring of the atmosphere. While GOME demonstrated the first satellite sensitivity to tropospheric nitrogen dioxide, SCIAMACHY possesses superior performance, with a spatial resolution of 60 x 30 kilometres compared to 320 x 40 km for its predecessor.
SCIAMACHY also observes the atmosphere in two different ways - downwards or nadir-sounding' as well as 'limb-sounding' along the direction of flight - and with a larger spectral range than its predecessor.
The increase in nitrogen dioxide levels seen is an unfortunate side effect of economic success. China's industrial boom has seen it become the world's largest consumer of copper, aluminium and cement and the second bigger importer of oil. Car ownership within the country has been doubling every few years.
"China's nitrogen dioxide concentration varies according to season," Burrows adds. "There is more in the winter as a result of differing emiss
Source:European Space Agency