A new frontier in CO₂ flux measurements using a highly portable DIAL laser system

Volcanic CO₂ emissions play a key role in the geological carbon cycle, and monitoring of volcanic CO₂ fluxes helps to forecast eruptions. The quantification of CO₂ fluxes is challenging due to rapid dilution of magmatic CO₂ in CO₂-rich ambient air and the diffuse nature of many emissions, leading to large uncertainties in the global magmatic CO₂ flux inventory. Here, we report measurements using a new DIAL laser remote sensing system for volcanic CO₂ (CO₂ DIAL). Two sites in the volcanic zone of Campi Flegrei (Italy) were scanned, yielding CO₂ path-amount profiles used to compute fluxes. Our results reveal a relatively high CO₂ flux from Campi Flegrei, consistent with an increasing trend. Unlike previous methods, the CO₂ DIAL is able to measure integrated CO₂ path-amounts at distances up to 2000 m using virtually any solid surface as a reflector, whilst also being highly portable. This opens a new frontier in quantification of geological and anthropogenic CO₂ fluxes.