Evidence of New Particle Formation Within Etna and Stromboli Volcanic Plumes and Its Parameterization From Airborne In Situ Measurements

• Published in: Journal of geophysical research. Atmospheres 2019-05, Vol.124 (10), p.5650-5668
• Main Authors: Sahyoun, Maher, Freney, Evelyn, Brito, Joel, Duplissy, Jonathan, Gouhier, Mathieu, Colomb, Aurélie, Dupuy, Regis, Bourianne, Thierry, Nowak, John B., Yan, Chao, Petäjä, Tuukka, Kulmala, Markku, Schwarzenboeck, Alfons, Planche, Céline, Sellegri, Karine
• Format: Article
• Language: English
• Subjects: Aerosol dynamics; aerosol formation rate parameterization; Aerosol particles; Aerosols; Airborne sensing; Boundary layers; Climate; Cloud properties; Clouds; Earth; Earth Sciences; Emission measurements; Etna and Stromboli; Geophysics; In situ measurement; Instrumentation; Jupiter; Mesoscale models; new particle formation; Ocean, Atmosphere; Parameterization; Particle formation; Plumes; Radiation budget; Sciences of the Universe; Solar radiation; Sulfur; Sulfur dioxide; Sulfuric acid; Sulphur; Sulphur dioxide; Sulphuric acid; Troposphere; Volcanic activity; Volcanic ash; Volcanic gases; volcanic plume; Volcanic plumes; volcanic secondary aerosols; Volcanoes; Volcanology; Weather
• ISSN: 2169-897X; 2169-8996
• DOI: 10.1029/2018JD028882

Volcanic emissions can significantly affect the Earth's radiation budget by emitting aerosol particles and gas‐phase species that can result in the new particle formation (NPF). These particles can scatter solar radiation or modify cloud properties, with consequences on health, weather, and climate. To our knowledge, this is the first dedicated study detailing how gas‐phase precursors emitted from volcanic plumes can influence the NPF. A series of airborne measurements were performed around the Etna and Stromboli volcanoes within the framework of the CLerVolc and STRAP projects. The ATR‐42 aircraft was equipped with a range of instrumentation allowing the measurement of particle number concentration in diameter range above 2.5 nm and gaseous species to investigate the aerosol dynamics and the processes governing the NPF and their growth within the volcanic plumes. We demonstrate that NPF occurs within the volcanic plumes in the free troposphere (FT) and boundary layer (BL). Typically, the NPF events were more pronounced in the FT, where the condensational sink was up to two orders of magnitude smaller and the temperature was ~20 °C lower than in the BL. Within the passive volcanic plume, the concentration of sulfur dioxide, sulfuric acid, and N2.5 were as high as 92 ppbV, 5.65 × 108 and 2.4 × 105 cm−3, respectively. Using these measurements, we propose a new parameterization for NPF rate (J2.5) within the passive volcanic plume in the FT. These results can be incorporated into mesoscale models to better assess the impact of the particle formed by natural processes, that is, volcanic plumes, on climate. Key Points New particle formation was evidenced to occur within different volcanic plumes of Etna and Stromboli and was more pronounced in the free troposphere The growth of the newly formed particles to the CCN active size was observed to occur within the volcanic plumes in different rates A novel parameterization rate of new particle formation within the Etna's volcanic passive plume was proposed based on the actual measurements