A model study of the pollution effects of the first 3 months of the Holuhraun volcanic fissure: comparison with observations and air pollution effects

• Published in: Atmospheric Chemistry and Physics
• Main Authors: B. M. Steensen, M. Schulz, N. Theys, H. Fagerli
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2016
• Subjects: Physics; QC1-999; Chemistry; QD1-999; Norway; Holuhraun; Iceland; North Atlantic; Northern Norway
• Online Access: https://doi.org/10.5194/acp-16-9745-2016; https://doaj.org/article/6328fd27ba794e79b66be8ad36353dcb

The volcanic fissure at Holuhraun, Iceland started at the end of August 2014 and continued for 6 months to the end of February 2015, with an extensive lava flow onto the Holuhraun plain. This event was associated with large SO 2 emissions, amounting up to approximately 4.5 times the daily anthropogenic SO 2 emitted from the 28 European Union countries, Norway, Switzerland and Iceland. In this paper we present results from EMEP/MSC-W model simulations to which we added 750 kg s −1 SO 2 emissions at the Holuhraun plain from September to November (SON), testing three different emission heights. The three simulated SO 2 concentrations, weighted with the OMI (Ozone Monitoring Instrument) satellite averaging kernel, are found to be within 30 % of the satellite-observed SO 2 column burden. Constraining the SO 2 column burden with the satellite data while using the kernel along with the three simulated height distributions of SO 2 , we estimate that the median of the daily burdens may have been between 13 and 40 kt in the North Atlantic area under investigation. We suggest this to be the uncertainty in the satellite-derived burdens of SO 2 , mainly due to the unknown vertical distribution of SO 2 . Surface observations in Europe outside Iceland showed concentration increases up to > 500 µg m −3 SO 2 from volcanic plumes passing. Three well identified episodes, where the plume crossed several countries, are compared in detail to surface measurements. For all events, the general timing of the observed concentration peaks compared quite well to the model results. The overall changes to the European SO 2 budget due to the volcanic fissure are estimated. Three-monthly wet deposition (SON) of SO x in the 28 European Union countries, Norway and Switzerland is found to be more than 30 % higher in the model simulation with Holuhraun emissions compared to a model simulation with no Holuhraun emissions. The largest increases, apart from extreme values on Iceland, are found on the coast of northern Norway, a region with frequent ...