Author/Authors :
Petنjن، نويسنده , , T. and Laakso، نويسنده , , L. and Grِnholm، نويسنده , , T. and Launiainen، نويسنده , , S. and Evele-Peltoniemi، نويسنده , , I. and Virkkula، نويسنده , , A. and Leskinen، نويسنده , , A. and Backman، نويسنده , , J. and Manninen، نويسنده , , H.E. and Sipilن، نويسنده , , M. and Haapanala، نويسنده , , S. and Hنmeri، نويسنده , , K. and Vanhala، نويسنده , , E. and Tuomi، نويسنده , , T. and Paatero، نويسنده , , J. and Aurela، نويسنده , , M. and Hakola، نويسنده , , H. and Makkonen، نويسنده , , U. and Hellén، نويسنده , , H. and Hillamo، نويسنده , , R. and Vira، نويسنده , , J. and Prank، نويسنده , , M. and Sofiev، نويسنده , , M. and Siitari-Kauppi، نويسنده , , M. and Laaksonen، نويسنده , , A. and Lehtinen، نويسنده , , K.E.J. and Kulmala، نويسنده , , M. and Viisanen، نويسنده , , Y. and Kerminen، نويسنده , , V.-M.، نويسنده ,
Abstract :
The volcanic ash cloud from Eyjafjallajökull volcanic eruption seriously distracted aviation in Europe. Due to the flight ban, there were only few in-situ measurements of the properties and dispersion of the ash cloud. In this study we show in-situ observations onboard a hot air balloon conducted in Central Finland together with regional dispersion modelling with SILAM-model during the eruption. The modeled and measured mass concentrations were in a qualitative agreement but the exact elevation of the layer was slightly distorted. Some of this discrepancy can be attributed to the uncertainty in the initial emission height and strength. The observed maximum mass concentration varied between 12 and 18 μg m−3 assuming a density of 2 g m−3, whereas the gravimetric analysis of the integrated column showed a maximum of 45 μg m−3 during the first two descents through the ash plume. Ion chromatography data indicated that a large fraction of the mass was insoluble to water, which is in qualitative agreement with single particle X-ray analysis. A majority of the super-micron particles contained Si, Al, Fe, K, Na, Ca, Ti, S, Zn and Cr, which are indicative for basalt-type rock material. The number concentration profiles indicated that there was secondary production of particles possibly from volcano-emitted sulfur dioxide oxidized to sulfuric acid during the transport.
