Putting a value on ESA’s Aeolus wind mission

Aeolus is an Earth Explorer research mission, developed within what is now ESA’s FutureEO programme – a programme that harnesses novel ideas and concepts to forge pioneering satellite missions to understand Earth for a more sustainable future.

Aeolus set out to demonstrate how new spaceborne laser technology can profile Earth’s winds.

This remarkable piece of satellite technology involves firing pulses of ultraviolet light from the satellite’s laser towards Earth. This light bounces off air molecules and particles such as dust in the atmosphere.

The small fraction of light that scatters back towards the satellite is collected by a large telescope.

Through the measurement of the Doppler shifts in the return signals, the horizontal speed of the wind in the lowermost 30 km of the atmosphere are derived, making Aeolus the first satellite mission to deliver profiles of Earth’s wind on a global scale.

These profiles contribute to climate research and to forecasting the weather.

Aeolus has also been used to track events in near-realtime, such as the Hunga Tonga volcanic eruption which happened early this year.

Tracking ash plumes is important to warn the airline industry of potential hazards as ash clouds can reduce visibility and damage aircraft engines.

As well as demonstrating that its novel technology works and that its resulting benefit climate science, numerical weather predication and weather forecasts, a recent report by London Economics found that Aeolus has brought some real economic benefits to Europe.

The report states that the total benefits of Aeolus data and information to European stakeholders and society is as much as €3.5 billion over the lifetime of the mission.

This figure is based several aspects of the mission such as the fact that Aeolus data have been used to understand and predict extreme weather variations in both Europe and North America.

Also, major improvements were made in data availability at the poles and the equator. In these regions, the mean error between predictions and observations was reduced by more than 4% only with the addition of Aeolus.

ESA’s free and open data access also reduces the barriers to adoption of data and therefore increases user uptake. Without such policy, budget constraints would prevent the value of information to trickle down in the entire value chain of the European economy.

During the COVID pandemic, data from Aeolus filled the gap left by the aviation sector. With fewer flights, measurements from air traffic reduced accordingly. Fortunately, Aeolus was available, and the mission was used to help maintain the data input to operational weather forecast models.

Launched in 2018, Aeolus was designed to deliver wind profiles from space for three years, but has clearly exceeded expectations. Nevertheless, the mission cannot live on forever, and a future series of Doppler wind lidar satellites, Aeolus-2, is planned to continue delivering wind profiles from space.

The London Economics report states that a series of two Aeolus-2 satellites, providing ten years of observations, could benefit the European economy by €7.1 billion, so more than double that of Aeolus.

Aeolus-2 is included in the Earth Observation Proposal at ESA’s upcoming Council at Ministerial Level. It is a prime example of an Earth Explorer research mission developed within ESA's FutureEO programme providing sound heritage to develop an operational mission – a mission that delivers systematic data for environmental or weather services.

In this case, the development of a new wind lidar system will be carried out in cooperation with European Organisation for the Exploitation of Meteorological Satellites, Eumetsat.