Statistical validation of Aeolus L2A particle backscatter coefficient retrievals over ACTRIS/EARLINET stations on the Iberian Peninsula Abril Gago, Jesús Guerrero Rascado, Juan Luis Bravo Aranda, Juan Antonio Bermejo Pantaleón, Diego Granados Muñoz, María José Ortiz Amezcua, Pablo Jiménez Martín, Marta María Alados Arboledas, Lucas The analysis in this work has been performed in the framework of the Aeolus Scientific Calibration and Validation Team (ACVT) activities. The authors acknowledge the ESA project "Aeolus L2A aerosol and cloud product validation using the European Aerosol Research Lidar Network EARLINET" (project no. 5166). The ACTRIS-2 Research Infrastructure Project and Implementation Project of the European Union's Horizon 2020 Research and Innovation program (grant nos. 654109 and 871115) and GRASP-ACE (grant no. 778349) are also acknowledged. This work is related to activities within the COST Action CA18235 PROBE (PROfiling the atmospheric Boundary layer at European scale). This work was also supported by the Spanish Ministry of Economy and Competitiveness (project nos. CGL2015-73250-JIN, CGL2016-81092-R, CGL2017-83538-C3-1R and CGL2017-90884-REDT); the Spanish Ministry of Science and Innovation (project nos. PID2019-103886RB-I00, PID2020117825GB-C21 and PID2020-120015RB-I00); the Unity of Excellence "Maria de Maeztu" (project MDM-2016-0600), financed by the Spanish State Research Agency (AEI); the national Portuguese funds, through FCT -Fundacao para a Ciencia e Tecnologia, I.P. (project nos. UIDB/04683/2020, UIDP/04683/2020, PTDC/CTAMET/29678/2017 and 0753_CILIFO_5_E); and the Regional Government of Andalusia (project no. P18-RT-3820). The authors thankfully acknowledge the FEDER program for the instrumentation used in this work. Maria Jose Granados-Munoz has received funding from the European Union's Horizon 2020 Research and Innovation program via a Marie Sklodowska-Curie grant (grant no. 796539). Juan Antonio Bravo-Aranda received funding from the Marie Sklodowska-Curie Action Cofund 2016 EU project -Athenea3i grant (grant no. 754446). Pablo Ortiz-Amezcua received funding from the National Science Centre (NCN, Poland) in the framework of the SONATINA 5 project (project no. DEC2021/40/C/ST10/00023). Finally, the authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (https://www.ready.noaa.gov/index.php, last access: 7 January 2022) used in this publication. The Global Observing System (GOS) has encountered some limitations due to a lack of worldwide real-time wind measurements. In this context, the European Space Agency (ESA) has developed the Aeolus satellite mission, based on the ALADIN (Atmospheric Laser Doppler Instrument) Doppler wind lidar; this mission aims to obtain near-real-time wind retrievals at the global scale. As spin-off products, the instrument retrieves aerosol optical properties such as particle backscatter and extinction coefficients. In this work, a validation of Aeolus reprocessed (baseline 10) co-polar backscatter coefficients (beta(part)(Aeolus)) is presented through an intercomparison with analogous ground-based measurements taken at the ACTRIS (Aerosols, Clouds and Trace gases Research InfraStructure Network)/EARLINET (European Aerosol Research Lidar Network) stations of Granada (Spain), Evora (Portugal) and Barcelona (Spain) over the period from July 2019 until October 2020. Case studies are first presented, followed by a statistical analysis. The stations are located in a hot spot between Africa and the rest of Europe, which guarantees a variety of aerosol types, from mineral dust layers to continental/anthropogenic aerosol, and allows us to test Aeolus performance under different scenarios. The so called Aeolus-like profiles (beta(part)(Aeolus) (like, 355)) are obtained from total particle backscatter coefficient and linear particle depolarization art ratio (delta(part)(linear)) profiles at 355 and 532 nm measured from the surface, through a thorough bibliographic review of dual-polarization measurements for relevant aerosol types. Finally, the study proposes a relation for the spectral conversion of delta(part)(linear), which is implemented in the Aeolus-like profile calculation. The statistical results show the ability of the satellite to detect and characterize significant aerosol layers under cloud-free conditions, along with the surface effect on the lowermost measurements, which causes the satellite to largely overestimate copolar backscatter coefficients. Finally, the Aeolus standard correct algorithm middle bin (SCAmb) shows a better agreement with ground-based measurements than the standard correct algorithm (SCA), which tends to retrieve negative and meaningless coefficients in the clear troposphere. The implementation of Aeolus quality flags entails a vast reduction in the number of measurements available for comparison, which affects the statistical significance of the results. 2022-02-23T07:50:06Z 2022-02-23T07:50:06Z 2022-01-27 info:eu-repo/semantics/article Abril-Gago, J... [et al.]: Statistical validation of Aeolus L2A particle backscatter coefficient retrievals over ACTRIS/EARLINET stations on the Iberian Peninsula, Atmos. Chem. Phys., 22, 1425–1451, [https://doi.org/10.5194/acp-22-1425-2022], 2022. http://hdl.handle.net/10481/72946 10.5194/acp-22-1425-2022 eng info:eu-repo/grantAgreement/EC/H2020/654109 info:eu-repo/grantAgreement/EC/H2020/871115 info:eu-repo/grantAgreement/EC/H2020/796539 info:eu-repo/grantAgreement/EC/H2020/778349 info:eu-repo/grantAgreement/EC/H2020/754446 http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Copernicus