Aeolus

Aeolus is an ESA satellite that provides global observations of wind profiles. It is the first wind satellite that can measure winds globally, as it is able to calculate atmospheric winds also in cloud-free areas or winds throughout vertical wind columns. Aeolus can provide high-quality short and medium-range forecasts (between three to ten days ahead) both of the northern and the southern hemispheres. It can also produce useful information on ocean salinity and frozen expanses as well as insights into the wind’s influence on heat and soil moisture within the Earth's surface. The measurements from the satellite can contribute to long-term climate research and help scientists better understand global environmental challenges such as extreme natural disasters, global warming, and air pollution.

 

Aeolus is equipped with an Atmospheric Laser Doppler Instrument, called Aladin. Aladin comprises powerful lasers, one of the largest telescopes ESA has put into orbit and very sensitive receivers that measure the minute shifts in wavelength of light generated by the movement of molecules and particles in the atmosphere caused by the wind. The ultraviolet lidar – “laser radar” – emits 50 short, powerful pulses of ultraviolet light per second magnified by a 1.5-m-diameter telescope to shine through the entirety of the atmosphere from 320 km away in space. Within three one-thousandths of a second, this telescope can gather the resulting laser backscatter from aerosol droplets, dust particles, water vapor, and actual air molecules across different atmospheric layers. This "Doppler shift" is measured to derive wind velocities down to a few meters per second, taking a fresh sample every 200 km.