Aeolus

Aeolus is a European Space Agency (ESA) Earth Explorer mission, scheduled to be launched in August 2018 as part of the Living Planet Programme.

The mission is intended to have a lifetime of three years. The Earth Explorers are designed to address critical and specific issues that are raised by the science community, while at the same time demonstrating breakthrough technology in observing techniques.

Aeolus will demonstrate the capability of a spaceborne Doppler wind lidar to make accurate, globally-distributed measurements (polar orbit) of vertical profiles of wind information in the troposphere and lower stratosphere (near surface to 30 km). It will measure single horizontal line-of-sight (HLOS) winds, perpendicular to the satellite track, by aiming an ultraviolet (UV) laser into the atmosphere and then detecting the Doppler-shift of the backscattered light from both molecules (clear air) and particles (clouds/aerosols). Aeolus is seen as a pre-operational mission, demonstrating new laser technology and paving the way for future meteorological satellites to measure atmospheric winds.

The Aeolus mission has suffered long delay due to problems encountered with the state-of-the-art UV laser technology, however this has now been resolved and it is set to be launched in August 2018.

Further details on the mission can be found from the Aeolus Science Report (2008) and from Stoffelen et al. (2005).

Role of ECMWF

ECMWF is contracted by ESA to produce Aeolus wind products suitable for use in NWP. In particular, ECMWF is responsible for the development of the wind retrieval software through collaboration with KNMI (Royal Netherlands Meteorological Institute), Météo-France and DLR (German Aerospace Centre). ECMWF has been chosen as the Level-2 Meteorological Processing Facility so it will process wind products (referred to as Level-2B wind products) and auxiliary meteorological data products for ESA in an operational manner during the mission’s lifetime.

ECMWF will also be responsible for the monitoring of Aeolus wind retrievals, and will assess the impact of Aeolus winds on the global NWP system. The intention is to assimilate HLOS winds operationally if they can provide the expected positive impact. ECMWF will also participate in readiness tests, Calibration/Validation activities and the mission’s Commissioning Phase.

The Aeolus Level-2B processing software along with detailed documentation is made available for NWP centres from the website: https://confluence.ecmwf.int/display/AEOL/Aeolus+Level-2B+Processor+Package.

It is expected that an increase in wind profile information will be a valuable addition to the global observing system, as was identified by a WMO expert team (Andersson & Sato, 2012). If Aeolus observations are of sufficient quality, they are expected to provide a significant positive impact on global NWP. Therefore, ECMWF has been separately contracted to investigate the expected impact of Aeolus data given some significant changes to the mission design over recent years.

See the ESA's project page