ESA Climate Studies - Aerosol Gas Survey

Aerosol optical depth measured by SEVIRI. Climate studies to benefit from 12 years of satellite aerosol data

Aerosols, very small particles suspended in the air, play an important role in the global climate balance and in regulating climate change.

They are one of the greatest sources of uncertainty in climate change models. ESA's GlobAerosol project has been making the most of European satellite capabilities to monitor them.

Using data from the Along Track Scanning Radiometer-2 on the ERS-2 satellite, the Advanced Along Track Scanning Radiometer and the Medium Resolution Imaging Spectrometer on Envisat and the Spinning Enhanced Visible & InfraRed Imager (SEVIRI) instrument on the Meteosat Second Generation, GlobAerosol has produced a global aerosol dataset going back to 1995. The full dataset is available on the GlobAerosol website.

Some aerosols occur naturally, originating from sea-spray, wind-blown dust, volcanic eruptions and biochemical emissions from oceans and forests, while others are produced through emissions from industrial pollution, fossil-fuel burning, man-made forest fires and agriculture.

Wind-blown dust
They are important because they strongly affect Earth’s energy balance in two ways: they scatter and absorb sunlight and infrared emission from Earth's surface, and act as condensation nuclei for the formation of cloud droplets. According to the Intergovernmental Panel on Climate Change, these effects tend to cool the planet to almost the same degree as carbon dioxide emissions warm it. These estimates are uncertain, however, so more data are needed.

Satellite data can provide essential information on the global distribution of aerosols to help understand the impact of these processes for the purposes of predicting weather and climate as well as for monitoring the transport of industrial pollution.