Aeolus horizontal-line-of-sight wind observations measured in the direction of the laser beam and projected onto the horizontal plane, on 1 September 2019 between about 6°N and 42°N. Aeolus was launched in 2018 to test the usefulness of direct wind profile observations from space for numerical weather prediction. It works by measuring the backscatter of laser light from air molecules (‘Rayleigh-clear’ data) and from clouds and aerosols (‘Mie-cloudy’ data).