An overview of Aeolus
ESA’s wind mission
Tommaso Parrinello, Thorsten Fehr, Viet Duc Tran, Denny Wernham, Luca Girardo, Irene Cerro,
Aditi Sathe, Trismono Candra Krisna, Peter Bickerton, Timon Hummel, Massimo Romanazzo,
Anne Grete Straume, Jonas Von Bismark, Thomas Kanitz, Emilio Alvarez, Oliver Reitebuch andMichael Rennie

Aeolus Industry Teams
Aeolus DISC Teams
Aeolus Flight Control Team
Aeolus Payload Ground Control TeamESA UNCLASSIFIED – For ESA Official Use Only

ESA-JAXA Pre-Launch EarthCARE
Science and Validation Workshop
13 - 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy
1Aeolus in a Nutshell▪ Aeolus is the second Earth Explorer Core Mission of ESA’s
Directorate of Earth Observation▪ Launch: 22nd August 2018 from Kourou on a Vega rocket▪ Orbit: Altitude of 320 km, inclination of 97deg, sun-synchronous,
7-days repeat cycle▪ Designed Mission Life: 3 years [until end 2021]▪ Line-of-sight (LOS) pointing 35o from nadir to capture profilesof single component horizontal wind (LOS wind is projected toHLOS)
Main Payload - ALADIN• Doppler Wind Lidar @355 nm -> 𝚫λ= 2.4 10-15 m (H+ ≈ 1.7 10-15 m)• One of the most sophisticated instruments ever to be put in orbit and last forsuch long time
• High-power ultraviolet (UV) laser transmitter containing ~80 optical functions
and different wavelength conversion• Extreme backscatter sensitivity via 1.5m telescope, 80 microns field stop andetalon spectrometers2Mission Objectives

Scientific Objectives
1. To improve the quality of weather forecasts
by providing Global Measurements ofhorizontal wind profiles in the troposphereand lower stratosphere
2. To advance our understanding ofatmospheric dynamics and climateprocesses•Long-term goal
Demonstrate space-based Doppler Wind
LIDARs capability for operational use3

Aeolus Achievements - Examples
Standard Deviation of Zonal
wind where Aeolus is changing
the analyses.
Courtesy ECMWF

Aeolus shows the Tonga
eruption to rise above
20.5 km, since the lidar
signal is totallyattenuatedImproved forecast impact over tropical troposphere and lower stratosphere.
Courtesy M. Rennie (ECMWF)

cxx

Dynamical and Surface Impacts of the January
2021 Sudden Stratospheric Warming in NovelAeolus Wind Observations, MLS and ERA5.
Courtesy Corwin J. Wright et al.

Atmospheric Gravity Waves in Aeolus
wind lidar observations.
Courtesy T. Banyard et al4

STRATEGIC MISSION GOALS [2021-2023]
Goal #1: Support the Tropical Campaign in summer 2021 withbest possible performance with Laser B to support both thevalidation and the science aspect of the campaign
Goal #2: Achieve the designed end of life-time (Dec 2021) withbest possible performance on both channels RAY and MIE tocomplete the prime mission objectives
Goal #3: Achieve within the extended life-time (2022), the best
possible performance on both channels or at least on one (e.g.
MIE)

Goal #4: Perform technological and science demonstration tosupport the Aeolus Follow on5

Aeolus Data Portfolio and Data Quality
Quality is constantly monitored and improved (random and systematic errors) allowing
also for quick reaction to performance issues• Random errors are primarily affected by lower UVtransmitted and emitted energy.

Data Access and Discovery• Biases - originated by different sources - have been
kept under control below mission requirements

3 September 2018 – 30 April 2023

Main ProductsContents• Aeolus Online Dissemination http service
http://aeolus-ds.eo.esa.int/oads/access

Level 1B

Geololocated preliminary Horizontal Line ofSight (HLOS) wind observations and usefulsignals for RAY amd MIE signals• ESA Aeolus Online Dissemination ftp service
ftps:// aeolus-ds.eo.esa.int

Level 2B

Ray and Mie wind profiles over thevertical bins

Level 2C

Superset of L2B data with wind fields
resulting from NWP assimilation processing• WMO in BUFR format
https://acquisition.ecmwf.int/index.html

Level 2A

Aerosol/Cloud optical profile prodcuts (i.e.
backscatter, optical depth, extinction, etc)

•VirES https://aeolus.services
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Aeolus Mission Status-The final overall performance of Aeolus mission has been beyond any expectations (e.g. 3-hour Neal Real Timedelivery of wind products to world-wide meteo centres was 99.23%).

-The ALADIN instrument operated for around 4.7 years accumulating some 7.6 billion laser shots.

-Following the end of mission operations on the 30th April 2023, Aeolus’ altitude started to decay naturally the 19th ofJune 2023 which allowed an additional number of tests to be performed as part of the End-of-Life activities.

-During these tests, FM-B was ramped up 180mJ and remained stable for more than one day with no sign ofdegradation, setting a new worldwide record for space-borne UV lasers.

-The ALADIN instrument was switched off on the 5th July 2023. The satellite reentered from space with an assisted (i.e.
semi-controlled) approach on the 28th July 2023 at 18:46 UTC over Antarctica close to entering the Atlantic corridor-Transition to Phase F [2024-2028] has started and the high-level timeline was consolidated.

-Preparation for the three conclusive Lessons Learnt Workshops (i.e Aeolus Reentry, Aeolus End-of-life Activities,Aeolus Phase E2) are ongoing.
Aeolus last measurement 30 April 2023 @23:59:51

Main Objective

FPHASE F TIMELINE

January 2024 – December 2028

Providehomogenous,
high-quality,validated wind and aerosol cloud
products from Aeolus in order tocontinue demonstrating positive impact
on NWP and enabling atmosphericscience and climate studies

Target Reentry

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A Special Mission
ScientificimpactInstrument

Innovation

Measurement Principles

Pierre Auger Observatory

Operations

People8

Conclusion
The mission has exceeded its designed lifetime (3-years). The overall performance of themission has been outstanding beyond any expectations despite a number or criticalproblems that have been solved or mitigated thanks to excellent cooperation between ESA
and industry
Aeolus has been providing globally wind measurements and has achieved its main
objectives with its data assimilated operationally by the most important meteo forecasting
centres in Europe and experimentally worldwide.

It has been a great journey for us
and I wish all the best toDue to the increase of SA and fuel limitation, nominal mission operations ended on 30thand his community.
April followed by the EarthCARE
start of the End-of-Life
activities (i.e. “a unique treasure ofinformation” cit. ASAG members). The satellite has reentered successfully on the 28th ofJuly 2023 over Antarctica.
Aeolus has been an innovative and unique mission. It is can be truly considered as THE
PATHFINDER for future DWL and has played a fundamental role in motivating ESA andEUMETSAT to develop EPS-Aeolus which fly in the next decade.
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