Space sensors highlight polluted air in India

Space sensors highlight polluted air in India

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Frascati, Italy, October 22, 2007: Air pollution is becoming one of the biggest dangers for the future of the planet, causing premature deaths of humans and damaging flora and fauna. With their vantage point from space, satellites are the only way to carry out effective global measurements of air-polluting emissions and their transboundary movement.

Scientists and researchers from around the world gathered at ESRIN, ESA’s Earth Observation Centre in Frascati, Italy, last week to discuss the contribution of satellite data in monitoring nitrogen dioxide in the atmosphere and to present the latest results of their ongoing atmospheric research that includes identifying hotspots, analysing trends and monitoring the effectiveness of mitigation efforts.

All of the satellite data used by the participants was acquired through the TEMIS project, part of ESA’s Data User Programme (DUP). The TEMIS Internet-based service offers near-real time data products, long-term data sets and forecasts from various satellite instruments related to tropospheric trace gas concentrations, aerosol and Ultra Violet radiation.

Emissions of gaseous pollutants have increased in India over the past two decades. According to Dr Sachin Ghude of the Indian Institute of Tropical Meteorology (IITM), rapid industrialisation, urbanisation and traffic growth are most likely responsible for the increase. Because of varying consumption patterns and growth rates, the distribution of emissions vary widely across India. In order to mitigate the causes of pollution, policy makers need to know the hardest hit regions.

Using nitrogen dioxide (NO2) data acquired from 1996 to 2006 by the Global Ozone Monitoring Experiment (GOME) instrument aboard ESA’s ERS-2 satellite and the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument aboard ESA’s Envisat, Ghude was able to identify the major NO2 hotspots, quantify the trend over major industrial zones and identify the largest contributing regions.

“Nitrous oxide emissions over India is growing at an annual rate of 5.5 percent/year and the location of emission hot spots correlates well with the location of mega thermal power plants, mega cities, urban and industrial regions,” Ghude said. “Data from the 11-year time series of GOME and SCIAMACHY provide valuable information to improve estimates of nitrogen dioxide emissions as well as to identify the source regions and to study the regional ozone chemistry in light of seasonal meteorology.”