Reactive trace gases

The atmosphere is mainly composed of nitrogen and oxygen, but also of a large number of trace gases which, despite their low concentrations, play an important role for air quality.

Certain short-lived reactive gases are associated with pollution episodes. Ozone, sulfur dioxide and nitrogen oxides have therefore been measured continuously for more than 20 years at the Puy de Dôme station as part of the ACTRIS research infrastructure.

Different volatile organic compounds (VOCs) emitted by anthropogenic or biogenic sources are also measured at Puy de Dôme. The gases are trapped in cartridges and are then analyzed by gas chromatography/mass spectrometry (GC-MS). An online measurement system also using GC-FID chromatography (Gas Chromatography – Flame Ionization Detector), has been operational since 2018 and allows the continuous monitoring of certain volatile organic compounds which are tracers of pollution sources.

Contacts : Aurélie Colomb/Agnes Borbon