1. PROJECT ------------ Title: Radar-supported Next-Generation Forecasting of Volcanic Ash Hazard (R4AsH) Dates: February 2019 - February 2022 Funding organisation: NERC Grant no.: NE/S005218/1 2. DATASET ------------ Title: Outputs from a volcanic ash transport and dispersion model (NAME), source inversion system (InTEM) and SEVIRI satellite retrievals for the 2011 Grímsvötn eruption. Description: This dataset contains (1) the output of a volcanic ash transport and dispersion model (Numerical Atmospheric-dispersion Modelling Environment - NAME) simulations of the 2011 Grímsvötn eruption used in the UK Met Office volcanic ash source inversion system (InTEM), (2) SEVIRI satellite retrievals provided by kind permission of the UK Met Office that were used in InTEM inversion system, (3) output from the InTEM system for the Grímsvötn eruption (4) output of volcanic ash transport and dispersion model simulations used for comparison to satellite retrievals and to produce ash hazard risk maps. The use of this data is outlined in Natalie Harvey et al. (2020): The impact of ensemble meteorology on inverse modelling estimates of volcano emissions and ash dispersion forecasts: Grímsvötn 2011. Atmosphere (accepted). Publication Year: 2020 Simulation data Creator: Natalie Harvey Organisation: University of Reading Rights-holder: University of Reading Satellite data Creator: Mike Cooke Organisation: UK Met Office Rights-holder: UK Met Office 3. TERMS OF USE ----------------- Simulation data: (C) University of Reading 2020. This dataset is licensed by the rights-holder under a Creative Commons Attribution 4.0 International Licence: https://creativecommons.org/licenses/by/4.0/. Satellite data: (C) Crown Copyright 2020. This dataset is licensed by the rights-holder under the Non-commercial Government Licence 2.0: http://www.nationalarchives.gov.uk/doc/non-commercial-government-licence/version/2/. 4. CONTENTS ------------ File listing name_runs_intem_wet_dep.tar.gz contains concentration output at hourly resolution from NAME simulations using a nominal release rate (1 g/s) from each possible source term component (4km height range and 3-hourly time period) with wet deposition represented for each member of the meteorological ensemble. The posterior emissions determined by InTEM using linear combinations of these nominal simulations are described in Harvey et al. (accepted 2020). name_runs_intem_no_wet_dep.tar.gz contains concentration output at hourly resolution from NAME simulations using a nominal release rate (1 g/s) from each possible source term component (4km height range and 3-hourly time period) without wet deposition represented for each member of the meteorological ensemble. The posterior emissions determined by InTEM using linear combinations of these nominal simulations are described in Harvey et al. (accepted 2020). intem_runs_wet_dep.tar.gz contains the output files from the InTEM inversion with wet deposition represented for each member of the meteorological ensemble. intem_runs_no_wet_dep.tar.gz contains the output files from the InTEM inversion with wet deposition represented for each member of the meteorological ensemble. This output is used to determine the impact of wet deposition on the forecasts of volcanic ash following the Grimsvštn 2011 eruption and as source terms for NAME simulations that are used to compare to satellite retrievals of ash column loading and to create ash hazard risk maps as described in Harvey et al. (accepted 2020). grims_ens_runs_apriori.tar.gz contains .txt concentration output at hourly resolution from NAME simulations using the a priori source for each member of the meteorological ensemble. grims_ens_runs_posterior.tar.gz contains .txt concentration output at hourly resolution from NAME simulations using the inverted posterior source term for each member of the meteorological ensemble. This data was used to compare to satellite retrievals of ash column loading and to create ash hazard risk maps as described in Harvey et al. (accepted 2020). SEVIRI_grims.tar.gz contains .txt of retrieved ash column loading from SEVIRI averaged on to a 0.375 degree latitude by 0.5625 longitude (approximately 40 km x 40 km in mid latitudes) and averaged over 1 hour for ashy boxes and clear sky boxes. 5. METHOD and PROCESSING -------------------------- The method and processing used to create this data are described in Natalie Harvey et al. (2020): The impact of ensemble meteorology on inverse modelling estimates of volcano emissions and ash dispersion forecasts: Grímsvötn 2011. Atmosphere (accepted). The dispersion model data was created using NAME III Version 7.2. Full details of the NAME model can be found here: Jones, A., Thomson, D., Hort, M., Devenish, B. The UK Met Office’s next-generation atmospheric dispersion model, NAME III. In Air Pollution Modeling and its Application XVII; Springer, 2007; pp. 580-589. https://doi.org/10.1007/978-0-387-68854-1 Full details of the InTEM system can be found here: Pelley, R.E., Cooke, M.C., Manning, A.J., Thomson, D.J., Witham, C.S., Hort, M.C. Initial implementation of an inversion technique for estimating volcanic ash source parameters in near real time using satellite retrievals. Forecasting Research Technical Report No. 604;Met Office, 2015. https://library.metoffice.gov.uk/Portal/Default/en-GB/RecordView/Index/212804 Full details of the satellite retrieval applied to the SEVIRI radiances can be found here: Francis, P. N., M. C. Cooke, and R. W. Saunders (2012): Retrieval of physical properties of volcanic ash using Meteosat: a case study from the 2010 Eyjafjallajökull eruption. J. Geophys. Res., 117, D00U09. doi:10.1029/2011JD016788.