EMS Annual Meeting Abstracts
Vol. 22, EMS2025-612, 2025, updated on 18 Aug 2025
https://doi.org/10.5194/ems2025-612
EMS Annual Meeting 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Validating satellite observations of clouds with the ground-based ACTRIS cloud profiling network
Ewan O'Connor1, Simo Tukiainen1, Tuomas Siipola1, Lukas Pfitzenmaier2, Nathan Feuillard3, Matheus Tolentino da Silva4,5, and Juan Antonio Bravo Aranda4,5
Ewan O'Connor et al.
  • 1Finnish Meteorological Institute, Helsinki, Finland
  • 2Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany
  • 3Laboratoire Atmospheres et Observations Spatiales, Guyancourt, France
  • 4Andalusian Institute for Earth System Research (IISTA-CEAMA), Granada, Spain
  • 5Department of Applied Physics, University of Granada, Granada, Spain

The number of ground-based cloud profiling stations incorporating a cloud radar, ceilometer and multi-channel microwave radiometer have rapidly increased in recent years, with more than 20 stations now operating within the ACTRIS cloud profiling network and at least 5 more associated with the wider Cloudnet network. The majority of the cloud profiling stations are now providing data within about two hours with full product generation for these stations within a few minutes from receiving the data (meeting the requirement for real-real-time data delivery, RRT, which is within 3 hours of measurement). Decade or longer time series are available from at least 8 sites and comprehensive quality control and calibration procedures are applied across the network.

Two satellite calibration and validation pilots were performed during the EU H2020 project ATMO-ACCESS, which demonstrated that the increase in number of stations, the quality control applied and the reliable RRT operational capability of the ACTRIS network, were of significant benefit for the two users, EUMETSAT and ESA.

One pilot was dedicated to EUMETSAT cloud products obtained from both polar orbiters and geostationary satellites; here, the priority was to deliver consistent products from across the network with RRT provision for operational evaluation and over a long time-frame for statistical reliability.

For the second pilot, the task was to evaluate the ESA / JAXA satellite Cloud, Aerosol and Radiation Explorer (EarthCARE) which is the first Doppler cloud radar in space. The Doppler radar observations enable better characterization of cloud and precipitation processes, classification of hydrometeor types and investigation of cloud dynamics and, given that this is the first observation of in-cloud Doppler velocities from a spaceborne radar, extensive validation of these satellite observed Doppler velocities using ground-based Doppler velocities from the ACTRIS-Cloudnet cloud profiling network is under way.

We wil present results from both of these calibration/validation activities, and describe some of the improvements made to the ground-based network operations to enable these.

How to cite: O'Connor, E., Tukiainen, S., Siipola, T., Pfitzenmaier, L., Feuillard, N., Tolentino da Silva, M., and Bravo Aranda, J. A.: Validating satellite observations of clouds with the ground-based ACTRIS cloud profiling network, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-612, https://doi.org/10.5194/ems2025-612, 2025.