Seminar

Abstract

The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System) operates a global-scale monitoring system for atmospheric trace gases, aerosols and clouds utilising existing global civil aircraft. This new monitoring infrastructure builds on the heritage of the former 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). IAGOS is now a major contributor to the in-situ component of the Copernicus Atmosphere Monitoring Service (CAMS), the successor to the Global Monitoring for the Environment and Security - Atmospheric Service (GAS), and is providing data for users in science, weather services and atmospherically relevant policy.

IAGOS is unique in collecting regular in-situ observations of reactive gases, greenhouse gases, and aerosol concentrations in the extra-tropical upper troposphere/lowermost stratosphere (UTLS) over mid-latitudes at high spatial resolution. It also provides routine vertical profiles of these species in the troposphere over continental sites or regions, many of which are undersampled by other networks or sampling studies, particularly in Africa, South East Asia, and South America. In combination with MOZAIC and CARIBIC, IAGOS has provided long-term observations of atmospheric chemical composition in the UTLS since 1994. The longest time series are 20 years of temperature, H2O and O3, and 9-15 years of aerosols, CO, NOy, CO2, CH4, N2O, SF6, Hg, acetone, ~30 HFCs, and ~20 NMHCs.

Among the scientific highlights which have emerged from these data sets are: observations of extreme concentrations of O3 and CO over the Pacific basin that have never or rarely been recorded over the Atlantic region for the past 12 years; detailed information on the temporal and regional distributions of O3, CO, H2O, NOy, and aerosol particles in the UTLS, including the impacts of cross-tropopause transport, deep convection and lightning on the distribution of these species; characterization of ice-supersaturated regions in the UTLS; and finally, improved understanding of the spatial distribution of upper tropospheric humidity (UTH) including the finding that the UTLS is much more humid than previously assumed.