ESA's Earth Explorer, Aeolus, was launched into space on 22 August 2018. This new satellite type provides novel global observations of wind profiles from the surface up to 30 km altitude.
Although there are several ways of measuring wind from a satellite, Aeolus utilises the active Doppler Wind Lidars (DWL) method. This is currently the only technology that can provide direct wind profile observations in clear air, inside thin clouds and aerosol layers and on top of thick clouds globally. In addition, a DWL provides information on cloud top heights and the vertical distribution of thin clouds and aerosol.
An improved knowledge of Earth's wind fields will lead to progress in atmospheric dynamics research and weather forecasting. Forecast impact experiments by a number of leading meteorological institutes across the world have shown that Aeolus observations lead to an improvement of operational weather forecasting. The experiments show that the impact is largest in the tropics, southern hemisphere, polar areas and in the upper troposphere and lower stratosphere, where there are currently very few direct wind observations in the Global Observing System of the World Meteorological organization (WMO).
The provision of global wind profiles will also benefit climate research. Climate models are similar to weather models, but predict the evolution of the coupled Earth System (atmosphere, land, ocean and ice) on the scale of years rather than days. As for weather forecast models, the key atmospheric variables in climate models are wind, temperature, pressure and humidity. The Aeolus winds will be used to evaluate climate models, and for the improvement of modelling of the global atmospheric transport and cycling of energy, water, aerosols and chemicals.