Satellites are the best available measuring tool for tracking air pollution caused by humans on a global scale, yet are so far underutilised as a technology, says atmosphere researcher Pieternel Levelt. Since 2004 Levelt has been the principal investigator of OMI, the world leading satellite instrument for studying air pollution in the earth’s atmosphere. The instrument has been providing a steady stream of data on the ozone layer, but also on nitrogen dioxide and other harmful air pollutants.


To this day, the OMI instrument plays a leading role in creating long series of measurements which is of great importance to monitoring air quality and the climate. ''This includes measurements concerning the ozone layer, but also a lot of trends for air quality. OMI currently has the longest measurement series for nitrogen dioxide and sulphur dioxide with global coverage, which is highly unique for a satellite instrument," states Levelt with visible pride.

From religion to economy

Many types of information can be derived from this data, right down to a country’s dominant religion. Levelt: "It’s really incredibly interesting. Human and economic activity can be deduced from the quantity of nitrogen dioxide a country emits. This quantity drops considerably on religious holidays. We can deduce, for instance, that economic growth has halted in Dubai, while emissions of nitrogen dioxide increased in China till about 2014, and still increase in India and Africa."

Measuring air pollution from a height of 800 km

A lot more will be possible in the not too distant future. OMI’s successor is currently being prepared, the TROPOMI satellite. "The latter will also measure methane and carbon monoxide in the atmosphere and it will also provide more information on clouds. The instrument’s sensitivity and resolution have also been improved. TROPOMI will enable us to distinguish the air pollution over Rotterdam’s port from that above the city centre, seen from a height of 800 km!"

Levelt argues that satellites offer a reliable means of monitoring the emission of air pollutants. Such monitoring is currently conducted mainly on the basis of information supplied by government bodies or companies. "However, a single satellite can map all the air pollution on the planet. This makes satellites in particular suitable as monitoring devices. Not only for the Netherlands, but globally. Many policy makers have scant awareness of the options already available to us."

Profile Prof. Pieternel Levelt
1987: Master in Chemistry, VU University Amsterdam
1992: PhD Physics, VU University Amsterdam
2007: Professor at University of Technology Eindhoven
2011: Professor of Remote Sensing of the Earth Atmosphere, TU Delft
Levelt is also Head of the R&D Satellite Observation Department at KNMI.

President Barack Obama used footage of OMI to discuss how NASA maps pollution from space and what it means for our future. This video message was broadcasted on 12 April 2016 by Science Channel.

Published: May 2016