The IDAEA Atmospheric Research network is a unique infrastructure for atmospheric research located in NE Spain. It is integrated by a Mobile Unit and a cluster of three observational platforms for atmospheric aerosols: Montsec (MSA, mountain site, 1590 m.a.s.l.), Montseny (MSY, Regional background, 720 m.a.s.l.), and Barcelona (BCN, Urban background, 78 m.a.s.l.). The infrastructure is particularly well-equipped for the in-situ characterization of aerosols (optical, physical, and chemical offline and online). All sites are also equipped with instruments for trace gases and two of them (MSY and BCN) will be equipped with instruments for VOCs online. Ceilometers are also operated at MSA and MSY, for remote sensing observation of atmospheric aerosols.

Access to the network permits investigating three different environments, connecting Air Quality, Health and Climate Research. It is the only infrastructure as such in the Western Mediterranean Basin, a unique region for atmospheric research given the high insolation, the specific meteorology, the elevated emissions of pollutants, and the frequent impact of dust outbreaks.

The IDAEA monitoring network forms part of the ACTRIS infrastructure. Access to the sites can be provided via ACTRIS and ATMO-ACCESS projects.

Services currently offered by the infrastructure:

• Access to equipment available at the sites and conditioned laboratories to deploy users’ own instruments for research projects and campaigns
• Technical developments and instrument testing in scientific
• Technical and administrative supportive environments provided by CSIC
• Capability of organizing training workshops on instrument utilization
• Data processing and result interpretation.