21 Jan 2013:
NASA Map Shows Air Pollution
Across Asia and the Middle East
New satellite data released by NASA provide dramatic visual evidence of the dangerous air quality reported from cities across Asia and the Middle East this month. Based on data collected from its
satellite-based Ozone Monitoring Instrument, a map released by NASA scientists
illustrates high levels of nitrogen dioxide (NO2) — shown in orange — over several major cities, including Istanbul, Tehran and New Delhi, during the first week of January. Satellite measurements of nitrogen dioxide concentrations are a good indicator of air quality since NO2 is produced by the same fossil fuel-burning processes that also send sulfur dioxide and aerosols into the atmosphere, such as from vehicles, industrial sites, and power plants. During the winter months, nitrogen dioxide often gets trapped near the earth's surface for long periods as a result of cold temperatures and strong high-pressure systems, contributing to small particle pollution. The high concentrations of NO2 illustrated in the NASA map, based on measurements from Jan. 1 to 8, coincided with reports
from several cities of yellow hazy skies, unhealthy air quality, and elevated cases of lung ailments.