The primary objective of the Aeolus mission was to demonstrate the Doppler Wind Lidar technique for measuring wind profiles from space. The missions aim was to provide observations of global wind profiles along the instrument line of sight direction over a minimum lifetime of three years. The data were intended for assimilation into Numerical Weather Prediction (NWP) models, improving the analyses and forecasting of the 3D vector wind field.

A secondary mission objective is to provide data sets suitable for the evaluation of climate models. Reliable short-term wind "climatologies" are needed to improve our understanding of atmospheric dynamics and the global atmospheric transport and cycling of energy, water, aerosols, chemicals and other airborne materials. The mission will, thus, provide data needed to address some of the key concerns of the World Climate Research Programme (WCRP) i.e. the quantification of climate variability, evaluation and improvement of climate models and process studies relevant to climate change. The newly acquired data will also help realise some of the objectives of the Global Climate Observing System (GCOS) i.e.

1. the study of the Earth's global energy budget (by measuring wind profiles globally)
2. the study of the global atmospheric circulation and related features such as precipitation systems, the El Niño and the Southern Oscillation phenomena and stratospheric/tropospheric exchange

The Aeolus mission objectives are further detailed as follows:

• improving NWP analyses and forecasting of the 3D vector wind field
• improved medium-range forecasts for the extra-tropical region through a better definition of planetary-scale waves
• improvements in forecasts of intense wind events through measurements of vertical wind shear (vertically resolved HLOS wind observations)
• improved modelling and forecasting of tropical dynamics through the provision of direct wind observation profiles
• provide data sets suitable for the evaluation of climate models
• improvements of the knowledge of the atmospheric state through the provision of atmospheric optical properties (cloud and aerosol spin-off products derived from the measured atmospheric backscatter)

The table outlines the measurement requirements for the Aeolus mission. These are based on information gained from the World Climate Research Programme and other organisations, which specify the accuracy and complexity of data required by the scientific and meteorological community.

(*) PBL = planetary boundary layer

Learn more about the science behind the Aeolus mission, and why its measurements are important: