Articles | Volume 17, issue 1
Atmos. Chem. Phys., 17, 551–574, 2017
Atmos. Chem. Phys., 17, 551–574, 2017

Research article 11 Jan 2017

Research article | 11 Jan 2017

Detecting volcanic sulfur dioxide plumes in the Northern Hemisphere using the Brewer spectrophotometers, other networks, and satellite observations

Christos S. Zerefos1,2,3,4, Kostas Eleftheratos2,5, John Kapsomenakis1, Stavros Solomos6, Antje Inness7, Dimitris Balis8, Alberto Redondas9, Henk Eskes10, Marc Allaart10, Vassilis Amiridis6, Arne Dahlback11, Veerle De Bock12, Henri Diémoz13, Ronny Engelmann14, Paul Eriksen15, Vitali Fioletov16, Julian Gröbner17, Anu Heikkilä18, Irina Petropavlovskikh19, Janusz Jarosławski20, Weine Josefsson21, Tomi Karppinen22, Ulf Köhler23, Charoula Meleti8, Christos Repapis4, John Rimmer24, Vladimir Savinykh25, Vadim Shirotov26, Anna Maria Siani27, Andrew R. D. Smedley24, Martin Stanek28, and René Stübi29 Christos S. Zerefos et al.
  • 1Research Centre for Atmospheric Physics and Climatology, Academy of Athens, Athens, Greece
  • 2Biomedical Research Foundation, Academy of Athens, Athens, Greece
  • 3Navarino Environmental Observatory (N.E.O.), Messinia, Greece
  • 4Mariolopoulos-Kanaginis Foundation for the Environmental Sciences, Athens, Greece
  • 5Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, Athens, Greece
  • 6Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS), National Observatory of Athens, Athens, Greece
  • 7European Centre for Medium-Range Weather Forecasts (ECMWF), Reading, UK
  • 8Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece
  • 9Izaña Atmospheric Research Center, AEMET, Tenerife, Canary Islands, Spain
  • 10Royal Netherlands Meteorological Institute (KNMI), De Bilt, the Netherlands
  • 11Department of Physics, University of Oslo, Oslo, Norway
  • 12Royal Meteorological Institute of Belgium, Brussels, Belgium
  • 13ARPA Valle d'Aosta, Saint-Christophe, Italy
  • 14Leibniz Institute for Tropospheric Research, Leipzig, Germany
  • 15Danish Meteorological Institute, Copenhagen, Denmark
  • 16Environment and Climate Change Canada, Toronto, Canada
  • 17PMOD/WRC, Davos Dorf, Switzerland
  • 18Climate Change Unit, Finnish Meteorological Institute, Helsinki, Finland
  • 19Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
  • 20Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland
  • 21Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
  • 22Arctic Research Centre, Finnish Meteorological Institute, Sodankylä, Finland
  • 23DWD, Meteorological Observatory Hohenpeißenberg, Hohenpeißenberg, Germany
  • 24Centre for Atmospheric Science, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK
  • 25A.M. Obukhov Institute of Atmospheric Physics, Kislovodsk, Russia
  • 26Institute of Experimental Meteorology, Obninsk, Russia
  • 27Department of Physics, Sapienza, University of Rome, Rome, Italy
  • 28Solar and Ozone Observatory, Czech Hydrometeorological Institute, Hradec Králové, Czech Republic
  • 29Federal Office of Meteorology and Climatology, MeteoSwiss, Payerne, Switzerland

Abstract. This study examines the adequacy of the existing Brewer network to supplement other networks from the ground and space to detect SO2 plumes of volcanic origin. It was found that large volcanic eruptions of the last decade in the Northern Hemisphere have a positive columnar SO2 signal seen by the Brewer instruments located under the plume. It is shown that a few days after the eruption the Brewer instrument is capable of detecting significant columnar SO2 increases, exceeding on average 2 DU relative to an unperturbed pre-volcanic 10-day baseline, with a mean close to 0 and σ = 0.46, as calculated from the 32 Brewer stations under study. Intercomparisons with independent measurements from the ground and space as well as theoretical calculations corroborate the capability of the Brewer network to detect volcanic plumes. For instance, the comparison with OMI (Ozone Monitoring Instrument) and GOME-2 (Global Ozone Monitoring Experiment-2) SO2 space-borne retrievals shows statistically significant agreement between the Brewer network data and the collocated satellite overpasses in the case of the Kasatochi eruption. Unfortunately, due to sparsity of satellite data, the significant positive departures seen in the Brewer and other ground networks following the Eyjafjallajökull, Bárðarbunga and Nabro eruptions could not be statistically confirmed by the data from satellite overpasses. A model exercise from the MACC (Monitoring Atmospheric Composition and Climate) project shows that the large increases in SO2 over Europe following the Bárðarbunga eruption in Iceland were not caused by local pollution sources or ship emissions but were clearly linked to the volcanic eruption. Sulfur dioxide positive departures in Europe following Bárðarbunga could be traced by other networks from the free troposphere down to the surface (AirBase (European air quality database) and EARLINET (European Aerosol Research Lidar Network)). We propose that by combining Brewer data with that from other networks and satellites, a useful tool aided by trajectory analyses and modelling could be created which can also be used to forecast high SO2 values both at ground level and in air flight corridors following future eruptions.

Short summary
The paper makes a convincing case that the Brewer network is capable of detecting enhanced SO2 columns, as observed, e.g., after volcanic eruptions. For this reason, large volcanic eruptions of the past decade have been used to detect and forecast SO2 plumes of volcanic origin using the Brewer and other ground-based networks, aided by satellite, trajectory analysis calculations and modelling.
Final-revised paper