In situ measurement of the Icelandic Holuhraun/ Bárðarbunga volcanic plume in an early "young state" using a LOAC

• Main Authors: Vignelles, Damien, Roberts, Tjarda, J, Carboni, Elisa, Ilyinskaya, Evgenia, Dagsson Waldhauserovà, Pavla, Berthet, Gwenael, Jegou, Fabrice, Baptiste Renard, Jean, Olafsson, Haraldur, Bergsson, Baldur, Yeo, Richard, Fannar Reynisson, Njall, Grainger, Roy, Pfeffer, Melissa, Lurton, Thibaut, Duverger, Vincent, Coute, Benoit
• Other Authors: Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales Paris (CNES)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2016
• Subjects: [SDU]Sciences of the Universe [physics]; Iceland
• Online Access: https://insu.hal.science/insu-03573541; https://insu.hal.science/insu-03573541/document; https://insu.hal.science/insu-03573541/file/EGU2016-298-1.pdf

International audience Volcanic eruptions have huge societal and economic consequences. In Iceland, one of the best known examples is the Laki eruption (1783-84 CE) (Thordarson and Self, 2003) which caused the death of > 20% of the Icelandic populations and likely increased European levels of mortality through air pollution (Witham and Oppenheimer, 2004). The recent fissure eruption at Holuhraun (31 August 2014 - 27 February 2015) was a major source of sulfur gases and aerosols and caused also both local and European-wide deteriorations to air quality (Gislason et al. 2015; Schmidt et al. 2015). The capability of atmospheric models to predict volcanic plume impacts is limited by uncertainties in the near-source plume state. Most in-situ measurements of the elevated plume involve interception of aged plumes that have already chemically or physically evolved. Small portable sensors airborne drone or balloon platforms offer a new possibility to characterize volcano plumes near to source. We present the results of a balloon flight through the plume emitted by Baugur the main vent during the night of the January 22th 2015. The balloon carrying a LOAC (Renard et al. 2015) has intercepted the plume at 8km distance downwind from the crater which represents a plume age of approximately 15 minutes. The plume was located in altitude between 2 and 3.1km above the sea level. Two layers were observed, a non-condensed lower layer and a condensed upper layer. The lower layer of 400m thick was characterized by a mode of fine particles centered on 0.2μm in diameter and a second mode centered on 2.3μm in diameter and a total particle concentration around 100 particles per cubic centimeter. The upper layer of 800m thick was a cloud-like signature with droplets centered on 20 μm in diameter and a fine mode, the total particles concentrations was 10 times higher than the first layer. The plume top height was determined between 2.7 and 3.1 km, the plume height is in good agreement with an estimate made by analysis of IASI ...