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

Volcanic CO emissions play a key role in the geological carbon cycle, and monitoring of volcanic CO fluxes helps to forecast eruptions. The quantification of CO fluxes is challenging due to rapid dilution of magmatic CO in CO-rich ambient air and the diffuse nature of many emissions, leading to large uncertainties in the global magmatic CO flux inventory. Here, we report measurements using a new DIAL laser remote sensing system for volcanic CO (CODIAL). Two sites in the volcanic zone of Campi Flegrei (Italy) were scanned, yielding CO path-amount profiles used to compute fluxes. Our results reveal a relatively high CO flux from Campi Flegrei, consistent with an increasing trend. Unlike previous methods, the CODIAL is able to measure integrated CO 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 CO fluxes.