Abstract
Aqueous sulphuric acid droplets, which constitute the background stratospheric aerosol, strongly absorb HNO3 and HCl under cold conditions. A thermodynamic model is used to predict partitioning of HNO3, HCl and H2O between gas and aerosol phases, and show that a 50‐fold increase in aerosol volume, observed in the Arctic stratosphere as temperature approached the frost point (188.9 K), can be explained in terms of uptake of HNO3 and H2O by liquid aerosols. Calculated degrees of saturation of the droplets with respect to solid hydrates, taking into account the reduction in vapour phase HNO3, suggest that the droplets remain liquid to the frost point. Near this temperature, they can yield larger aerosol volumes than would have been the case for solid NAT (HNO3•3H2O) particles. The depletion of gas phase HNO3 into enhanced volumes of liquid aerosols resulting from volcanic eruptions may hamper NAT formation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
