Introduction to ADM-Aeolus
ADM-Aeolus (or Aeolus for short) is the fifth planned satellite in the Living Planet Programme of the European Space Agency. The mission's objective is to provide profiles of high-quality wind observations from the surface to around 30 km altitude, using a Doppler wind lidar (DWL) instrument (known as ALADIN) in a near-polar sun-synchronous, dawn-dusk orbit (320 km altitude). The wind information is the horizontal line-of-sight (HLOS) component, in the direction perpendicular to the satellite's velocity. The mission is intended to have a minimum lifetime of three years.
ECMWF is contracted by ESA to develop, in collaboration with KNMI, the Aeolus Level 2B/C processing software i.e. the wind retrieval. The L2B wind retrieval algorithms have also been developed in the past in collaboration with Météo-France, DLR and LMD/IPSL. ECMWF will also generate the L2B products operationally at ECMWF, and provide the products to ESA for further distribution. ECMWF intend to assimilate the L2B winds in ECMWF's global NWP (Numerical Weather Prediction) model if demonstrated to improve forecast skill. Since ALADIN is a High Spectral Resolution Lidar; then it is also possible to derive information useful for atmospheric composition modelling. Aeolus will also provide information on the atmosphere's cloud and aerosol optical properties (via the Level-2A product). ECMWF has contributed to ESA funded observation impact studies to assess the potential impact of the Aeolus data in the past. We expect the Aeolus mission to have a positive impact on analysis and forecast quality, in particular the improvement of winds in the tropics.
More information is available at ESA's website.
Aeolus is expected to be launched in December 2017; this website provides a log of progress on the satellite: https://aeolusweb.wordpress.com/
A CAL/VAL rehearsal workshop will take place in March 2017: http://www.aeolus-calval-2017.org/
The L2B processing software
ECMWF and KNMI develop the ADM-Aeolus Level-2B wind retrieval software which produces HLOS winds suitable for use in NWP and meteorological research. The algorithms are described in Tan et al. (Tellus, A, 2008, 60, 2, 191-205), however note that there have been many modifications to the software since the reference was written (the Algorithm Theoretical Baseline document is up-to-date; see link below).
Downloading the L2B processing software
- The ADM-Aeolus Level-2B/C processing documentation v2.30 (including the Software Release Note, the Algorithm Theoretical Baseline and the Input/Output Data Definitions Interface Control documents) and associated datasets (needed to test the success of the installation) is available for download: Download Aeolus L2B/C documentation
- The source code (v2.30) can be downloaded for free from from our website (upon acceptance of the licence terms): Download Aeolus L2B processor package
- News on updates to the software, e.g. new deliveries, will be provided here
- Technical Notes prepared for ESA regarding the L2B/C processing can be downloaded here (they are useful to help understand more about the L2B products)
An artist's impression of the ADM-Aeolus satellite in orbit (courtesy of ESA).
An example of Aeolus L2B Rayleigh-clear wind observations, generated by running the genuine ground processing (i.e. L0/L1A/L1B/L2B processing) upon a realistic simulation of the raw data (E2S).