Porous aerosol in degassing plumes of Mt. Etna and Mt. Stromboli

摘要: Abstract. Aerosols of the volcanic degassing plumes from Mt. Etna and Stromboli were probed with in situ instruments on board Deutsches Zentrum fur Luft- und Raumfahrt research aircraft Falcon during contrail, volcano, cirrus experiment CONCERT September 2011. Aerosol properties analyzed using angular-scattering intensities particle size distributions measured simultaneously Polar Nephelometer Forward Scattering Spectrometer probes (FSSP series 100 300), respectively. are characterized by low values asymmetry parameter (between 0.6 0.75); effective diameter was within range 1.5–2.8 µm maximal lower than 20 µm. A principal component analysis applied to data indicates that scattering features aerosols different crater origins clearly distinctive contrails. Retrievals aerosol revealed particles "optically spherical" estimated real part refractive index interval 1.35 1.38. The interpretation these results leads conclusion plume porous air voids. Our estimates suggest contained about 18 35 % voids terms total volume.