A performance evaluation of CALPUFF dispersal model: the case of SO2 volcanic cloud released during the Holuhraun eruption (Iceland)

• Main Author: Helga Ívarsdóttir 1970-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2020
• Subjects: Umhverfis- og auðlindafræði; Loftmengun; Eldgos; Holuhraun; Gerðar; Iceland
• Online Access: http://hdl.handle.net/1946/35887

The Holuhraun eruption (2014-2015) emitted about 9.6 Tg of SO2 into the troposphere, causing repeated pollution events in Iceland. The performance of the CALPUFF dispersal model was evaluated by comparing simulated SO2 concentrations to observations from monitoring stations in Iceland, using the ECMWF Numerical Weather Prediction (NWP) data. The model sensitivity to spatial and temporal resolution of meteorological parameters was assessed by using also the HARMONIE high-resolution model. The volcanic plume was described by two emission sources, low-level and higher-level sources, representing the emission from the lava and the volcanic plume and their contribution to the SO2 concentration was assessed. The overall impact on the air quality was also examined. The low-level source was found responsible for pollution events in the nearfield while the higher-level source was responsible for the widespread distribution of SO2. The simulated pollution events showed, in general, too short duration and uncertainty of arrival time of about 4 hours. Using meteorological data with higher resolution did not improve the performance and severe under- or overestimations became more frequent. Using ECMWF NWP data and nine-hour running mean concentration showed the best results, and the quality of the CALPUFF model was found acceptable at most monitoring stations. The impact on air quality was significant during the eruption especially to the north and east of the eruption site. From the results, it can be concluded that the CALPUFF model is suitable for use in an eruption crisis such as the Holuhraun eruption. It provides vital information to the public and authorities where a dangerous concentration of SO2 can be expected and thus promotes appropriate actions. Frá Holuhraunsgosinu (2014-2015) bárust um 9.6 Tg af SO2 upp í veðrahvolfið og fylgdi því mikil loftmengun á Íslandi. Gæði CALPUFF dreifilíkansins var metin með því að bera saman reiknaðan styrk SO2 við mælingar sem gerðar voru á Íslandi, en notuð voru veðurgögn frá ...