Facilities
ACTRIS consists of an extensive network of National Facilities, and Central Facilities (Head Office, Data Centre and six Topical Centres).

Finland has 14 National Facilities fulfilling ACTRIS standards and contributes to five ACTRIS Central Facilities. The leadership of ACTRIS is in Finland; the statutory seat of ACTRIS ERIC (expected in 2022) and part of ACTRIS Head Office will be in Helsinki.

ACTRIS National Facilities consist of observational and exploratory platforms. Observational platforms are fixed ground-based stations that deliver long-term data based on a regular measurement schedule and common operation standards. Exploratory platforms are atmospheric simulation chambers, laboratory platforms and mobile platforms that perform dedicated experiments and contribute data on atmospheric constituents, processes, events or regions.

ACTRIS Central Facilities are the key operative entities of the Research Infrastructure, providing operation support to the National Facilities, and services to the ACTRIS users. Topical Centers are organised around the main scientific themes of ACTRIS: aerosol, clouds, and reactive trace gases, each with a particular focus on either remote sensing (from the ground) or in situ (near surface) measurement techniques.

Observational platforms
  • SMEAR I (Värriö, UH): Aerosol in situ, Cloud in situ, Reactive trace gases in situ. PI: Mikko Sipilä.
  • SMEAR II (Hyytiälä, UH): Aerosol in situ, Reactive trace gases in situ, Aerosol remote sensing, Cloud remote sensing. PI: Tuukka Petäjä
  • SMEAR III (Helsinki, UH&FMI): Aerosol in situ, Reactive trace gases in situ. PI: Leena Järvi and Tuukka Petäjä.
  • SMEAR IV (Kuopio, UEF&FMI): Aerosol in situ, Cloud in situ. PI: Annele Virtanen
  • Pallas Atmosphere-Ecosystem Supersite (FMI): Aerosol in situ, Cloud in situ, Reactive trace gases in situ, Cloud remote sensing. PI: Antti Hyvärinen.
  • Utö Atmospheric and Marine Research Station (FMI): Aerosol in situ, Reactive trace gases in situ. PI: Antti Hyvärinen.
  • Marambio (Antarctic Peninsula, FMI): Aerosol in situ. PI: EIja Asmi.
Exploratory platforms
  • Multi-wavelength Raman Lidar (FMI, mobile). Aerosol remote sensing. PI: Mika Komppula.
  • Doppler Cloud Radar (FMI, mobile). Cloud remote sensing. PI: Ewan O'Connor.
  • Doppler Lidars (FMI, mobile). Cloud remote sensing. PI: Ewan O'Connor.
  • Mobile Aerosol Laboratory (TAU, mobile).  Aerosol in situ, Reactive trace gases in situ. PI: Jorma Keskinen.
  • Unmanned Aerial Vehicle (FMI, mobile).  Aerosol in situ, Cloud in situ. PI: David Brus.
  • Kuopio Atmospheric Simulation Chambers (UEF, atmospheric simuation chamber). Aerosol in situ. PI: Annele Virtanen.
  • Aerosol, cluster and trace gas laboratory (UHEL, laboratory). Aerosol in situ, Reactive trace gases. PI: Tuukka Petäjä.
Finnish contribution to ACTRIS Central Facilities
  • Head Office: ERIC Management Unit, RI Operations Unit, Development and Relations Unit. PI: Interim ACTRIS Leader Eija Juurola
  • Centre for Aerosol In Situ Measurements: Unit for nanoparticle number concentration and size distribution measurements (namely Cluster Calibration Centre, CCC) (UH). PI: Silja Häme
  • Centre for Reactive Trace Gases In Situ Measurements: Unit for condensable vapor and aerosol presursor measurements using chemical ionisation mass spectrometry (namely CiGas-UHEL) (UH). PI: Silja Häme
  • Centre for Cloud Remote Sensing: Unit for Doppler Lidar data processing and quality control (FMI). PI: Ewan O’Connor
  • Data Centre: Unit for cloud remote sensing data (FMI). PI: Ewan O’Connor