Using DOAS traverses and atmospheric modelling to determine plumeheight and eruption rate of the 2015 Holuhraun eruption
(English)Manuscript (preprint) (Other academic)
The fissure eruption in Holuhraun — part of the Barðarbunga volcanic system — in 2014–2015 was amajor emitter of SO 2 . We present estimates of the SO 2 release rate of the eruption based on inverseatmospheric modelling and mobile-DOAS measurements made 80–240 km downwind of the main fissurevent. The FLEXPART-WRF and FLEXPART models are used to simulate the dispersion, using differentmeteorological data sets as input. Different inversion schemes were used to determine emission rates basedon modelled and measured column densities. The results were compared with OMI satellite observationsfor validation. This is, to our knowledge, the first case where a ground-based mobile-DOAS measurementshave been used in an atmospheric dispersion model for inverse modelling.
Comparisons were made between dispersion simulations based on meteorological data from different con-figurations of the WRF-model (at a resolution of 1.5 km); comparisons were also made using analysis andforecast data from ECMWF (at 0.2 degree resolution). Dispersion simulations based on data from ECMWFshowed better agreement with OMI satellite data than any of the simulations based on data from WRF.The inversion technique produced less variable emission rates compared to previous estimates, except duringperiods with low directional wind shear. Plume heights determined by the inverse modelling were below4 km for all periods.
We estimate the emission rate of the eruption to 500 kg/s in September 2014 and to 150 kg/s in thebeginning of February 2015, with a steady decrease over time.
Dispersion modelling, FLEXPART, Volcanic eruption, Sulfur dioxide, Holuhraun
Meteorology and Atmospheric Sciences
Research subject Meteorology
IdentifiersURN: urn:nbn:se:uu:diva-303950OAI: oai:DiVA.org:uu-303950DiVA: diva2:974722