The In-service Aircraft for a Global Observing System (IAGOS) is a distributed Research Infrastructure that operates a global-scale monitoring system for atmospheric trace gases, aerosols and clouds by using the existing provisions of the global air transport system to provide essential data on climate change and air quality. It complements the global observing system in addition to ground-based networks, dedicated research campaigns and observations from satellites, balloons, and ships. In order to provide optimal information, two complementary systems have been implemented, (i) IAGOS-CORE providing global coverage on a day-to-day basis of key observables and (ii) IAGOS-CARIBIC offering a more in-depth and complex set of observations with lesser geographical and temporal coverage.

IAGOS builds on the scientific and technological experience gained within the research projects MOZAIC (Measurement of Ozone and Water Vapour on Airbus in-service Aircraft) and CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container). In the ESFRI Roadmap since 2006, IAGOS developed the technical, organisational and legal concept during its Preparation Phase under the EU-funded IAGOS-ERI project. IAGOS was formally implemented in 2014 as an International non-profit Association under Belgian Law (AISBL) with its seat in Brussels. The scientific equipment deployed in IAGOS is owned and provided in-kind by the Members of IAGOS AISBL, who are also responsible for quality assurance of the measurements and for provision of the data.