Central Facilities


On the European level, ACTRIS operations are performed by ACTRIS Central Facilities (CFs) that include six Topical Centres, the Data Centre and the Head Office.

ACTRIS CFs represent the key operative entities of this RI and have a fundamental role as they provide services to the users according to the ACTRIS access policy as well as operation support to the National Facilities (NFs) to increase their performance. 

CFs participate in ACTRIS governance and management and provide services to the users accordingly to the user access policy as well as operation support to the National Facilities

Each CF may have several operational Units that can be situated in the same or different locations, and are operated by research performing organizations (RPOs) or by ACTRIS ERIC.

The CFs link the National Facilities, i.e. the observational and exploratory platforms, which are operated at the national level and produce the majority of the ACTRIS data.

ACTRIS Topical Centres

ACTRIS TCs are organized around the main scientific themes of ACTRIS: aerosols, clouds, and reactive trace gases, each with a particular focus on either remote sensing or in situ measurement techniques.

The key services and operation support provided by the TCs are

  • a) procedures and tools for quality assurance and quality control of ACTRIS measurements and data,
  • b) transfer of knowledge and training to ACTRIS operators and users, and
  • c) improvements of measurement methodologies for aerosols, clouds, and reactive trace gases.

The TCs operate at the state-of-the-art, fostering the implementation of validated new techniques in ACTRIS. To sustain a high level of performance and to stimulate the advancement of new techniques and methodologies, the TCs contribute to expert collaboration networks.

ACTRIS TCs under implementation include the existing European WDC and WCC components of GAW, the European component of the AERONET calibration facility, and complement centres already operating within other RIs (e.g. ICOS) or activities already ongoing in networks (NDACC) in Europe. Quality objectives are therefore compliant with international standards. Not all the TCs are currently at the same level of maturity, some are nearly operational while others are still in planning. Each of the TCs is foreseen to be organized as a consortium with several Units.

ACTRIS Central Facilities

  • ACTRIS Head Office (HO) is in charge of the strategic development and planning of ACTRIS services for users to solve important scientific questions and in promoting technology development and innovations.
  • HO also manages and oversees the future cooperation with RIs from other domains.
  • HO manages the ACTRIS scientific and technological development project portfolio and ensures that these collaborations lead to benefits for ACTRIS users, such as developments in services and operations, in line with the ACTRIS strategy.
  • HO coordinates and promotes ACTRIS services, handle internal and external communication, operate the legal entity, and ensure the strategic development and sustainability of ACTRIS.
  • The HO coordinates the RI at the European level, in close cooperation with the national ACTRIS consortia, the NFs, and the other CFs.
  • ACTRIS Data Centre (DC) is responsible for handling the ACTRIS data.
  • The primary role of ACTRIS DC is to compile, archive and provide access to well documented and traceable ACTRIS measurement data and data products, including digital tools for visualisations, data analysis and research.
  • As a tool for science, the highest priorities for ACTRIS DC is to maintain and increase the availability of ACTRIS data and data products relevant to climate and air quality research for all interested users.  
  • All primary measurement data and produced data products are made available to the users via the ACTRIS data portal.
  • ACTRIS DC will provide scientists and other user groups with free and open access to all ACTRIS data in accordance with the Access policy, and ACTRIS follows the open research data initiative of the Commission.
  • ACTRIS DC provides access to all measurements, both quality-assured data and near-real-time data, archived in interoperable topical data repositories handling very diverse type of data.
  • The mission of this TC is fundamental to improve the quality of the ACTRIS in situ aerosol data, by offering operation support to NFs, operating instruments for the physical or chemical in situ characterization of atmospheric aerosol particles as well as for particle sampling and subsequent laboratory analysis of these particles.
  • The mission of CARS is to offer operational support to ACTRIS National Facilities operating aerosol remote sensing instrumentation: profile and column observations. Relevant data include higher-level aerosol variables such as daytime extinction, backscatter, absorption and mass concentration (total, fine, coarse) and aerosol microphysical properties.
  • CARS includes AERONET-Europe calibration facility for photometers which complements the AERONET-NASA calibration facility in the USA.
  • There is also a close link to the Centre for Cloud Remote Sensing because automatic low-power lidars and ceilometers belong to the minimum required instrumentation of NFs for cloud remote sensing.
  • The mission of this TC is to offer operation support to ACTRIS National Facilities performing cloud in situ measurements.
  • The Centre will offer services for instrument calibration, provide training and knowledge transfer opportunities, and support instrument improvements and new technological developments for the relevant ACTRIS variables and measurement techniques.
  • The units of the Centre are partly operational and provide services as part of the EUROCHAMP-2020 project.
  • CCRES offers operation support to ACTRIS National Facilities operating cloud remote sensing instrumentation.
  • The Centre is elemental in developing calibration methods for cloud radars, microwave radiometry and Doppler Wind Lidars to be implemented on site (e.g. using calibration equipment or self-consistency techniques) and through mobile services (e.g. reference instruments or drone-based calibration).  
  • The mission of the TC is to provide operation support to NFs measuring key trace gases (non-methane hydrocarbons (NMHC), oxidized volatile organic compounds (OVOC), biogenic volatile organic compounds (BVOC), specific direct aerosol precursors, NO, and NO2) in order to produce traceable, reliable and quality controlled datasets with known compatibility.
  • The Centre develops and tests innovative gas analytical technologies and data evaluation algorithms and enhances the competence of operative personnel by intensive training courses.
  •  The Units of the Centre are in preparation.
  • CREGARS offers operation support to ACTRIS National Facilities operating reactive trace gases remote sensing instrumentation.
  • The Centre deals with different trace gas remote sensing techniques: Fourier-transform infrared spectrometry (FTIR), differential optical absorption spectrometry in the UV-visible range (UVVIS) and ozone LIDAR or O3 DIAL (differential absorption lidar).
  • The Centre provides essential knowledge about the observation techniques (measurement and retrieval) that may be applied in future applications (e.g., new satellite sensors, progress in air quality modelling etc.) to species that are currently not addressed.