ACTRIS : European Research Infrastructure for the observation of Aerosol, Clouds, and Trace gases

EARLINET: European Aerosol Research Lidar Network to Establish an Aerosol Climatology

AERONET: AErosol RObotic NETwork

IAGOS: In-service Aircraft for a Global Observing System (European Research Infrastructure)

ICOS: Integrated Carbon Observation System (European Research Infrastructure)

ITaRS: Initial Training for Atmospheric Remote Sensing (EU FP7 Marie Curie Initial Training Network (ITN))

Cloudnet: A network of stations for the continuous evaluation of cloud and aerosol profiles in operational NWP models

EMEP: European Monitoring and Evaluation Programme

ICARE: Clouds Aerosol Water Radiation Interactions (Atmospheric Data and Service Centre)