1. PROJECT ------------ Title: Protecting airspace infrastructure: A tool for calculating along-flight volcanic ash dosage Dates: 1 February 2017 - 30 April 2018 Funding organisation: Natural Environment Research Council Grant no.: NE/P009026/1 This dataset was generated at the University of Reading (UK) and was funded by the Natural Environment Research Council (NERC) under the Environmental Risks to Infrastructure Innovation Programme. The Numerical Atmospheric-dispersion Modelling Environment (NAME) was run on JASMIN and CEDA are acknowledged for providing access to the super-data-cluster (http://www.ceda.ac.uk/projects/jasmin/). The air-route data were generated using flightCode, which is software that was developed at the University of Reading by Marc Stringer (http://www.met.reading.ac.uk/~marc/it/flightCode/). 2. DATASET ------------ Title: Ash dosage and concentration risk dataset Description: This dataset provides data sufficient to plot Figures 2, 3, 4, 6 and 7 presented in Prata et al. (2018). Note that Figures 1 and 5 are schematic diagrams and data needed to plot Figure 8 can be made available upon request (a.t.prata@reading.ac.uk or h.f.dacre@reading.ac.uk). This dataset includes: 1) NAME dispersion model output for a control run of a hypothetical Katla eruption to 15 km (a.s.l.) on 1 January 2017 at 03:00 UTC. 2) Processed data that represent model agreement and risk maps. 3) Waypoints produced using flightCode (see link above) for an air-route from New York (JFK) to London (LHR) return. 4) Processed data that represent ash dosage, concentration, model agreement and risk calculated along an air-route from New York (JFK) to London (LHR) return. Publication Year: 2018 Creator(s): Andrew T. Prata, Helen F. Dacre, Emma E. Irvine and Keith P. Shine Organisation(s): University of Reading Rights-holder(s): University of Reading 3. TERMS OF USE ----------------- This dataset is licensed by the rights-holder(s) under a Creative Commons Attribution 4.0 International Licence: https://creativecommons.org/licenses/by/4.0/. 4. CONTENTS ------------ All data files listed below are provided in netcdf format. The units of variables and relevant metadata are included in each file. Below are brief descriptions for each file. Item 1: Filename: katla_control_run.nc Description: NAME dispersion model output for the Katla eruption scenario control run (used to plot Figure 2 of Prata et al., 2018). Note 1: These data are processed to produce 'thick layers' in the paper whereas the data provided are 25FL resolution (i.e. 'thin layers'). Note 2: Geopotential height data over-plotted on Figure 2 of Prata et al. (2018) are available on request (a.t.prata@reading.ac.uk or h.f.dacre@reading.ac.uk). Item 2: Filenames: FL000_FL200_0_2mg_agreement_map_lhs.nc FL000_FL200_2mg_agreement_map_lhs.nc FL000_FL200_4mg_agreement_map_lhs.nc FL000_FL200_10mg_agreement_map_lhs.nc FL200_FL350_0_2mg_agreement_map_lhs.nc FL200_FL350_2mg_agreement_map_lhs.nc FL200_FL350_4mg_agreement_map_lhs.nc FL200_FL350_10mg_agreement_map_lhs.nc FL350_FL550_0_2mg_agreement_map_lhs.nc FL350_FL550_2mg_agreement_map_lhs.nc FL350_FL550_4mg_agreement_map_lhs.nc FL350_FL550_10mg_agreement_map_lhs.nc Description: Percentage of ensemble members with ash concentrations above 0.2, 2, 4, 10 mg / m^3 for the three flight level ranges at time step 5 (T5) of the NAME simulation. These data were used to plot Figure 3 of Prata et al. (2018). Note: To plot the vertical cross-sections, the user must collocate these data with the JFK to LHR air-route (see Item 4). Item 3: Filenames: FL000_FL200_risk_layers_lhs.nc FL200_FL350_risk_layers_lhs.nc FL350_FL550_risk_layers_lhs.nc Description: Risk index maps (values from 1-9) for three flight level ranges at time step 5 (T5) of the NAME simulation. Used to plot Figure 6 of Prata et al. (2018). Item 4: Filename: JFK_LHR_return.nc Description: Waypoints for time-optimal return air-route from New York (JFK) to London (LHR) for FL350 at time step 5 (T5) of the NAME simulation. Note: This route is for 30 h after 1 Jan 2017 at 03:00 UTC (which is the eruption start time). Item 5: Filename: along_route_data.nc Description: Along-route ash concentration, dosage, risk and agreement for FL350 at time step 5 (T5) of the NAME simulation. These data were used to plot Figure 7 of Prata et al., 2018. Note: For the ash concentrations and dosages the minimum, maximum and median of the ensemble are given. 5. METHOD and PROCESSING -------------------------- The dispersion model data and air-route data were produced using NAME III Version 6.5 and flightCode Version 1, respectively. The model agreement and risk data were generated by processing a NAME 600-member ensemble dataset which was generated using Latin hypercube sampling (LHS). The ensemble dataset is available on request (h.f.dacre@reading.ac.uk). The method by which these data were processed is also described in Prata et al. (2018). The control run dispersion model data were post-processed following the 'thick layer' approach of the London Volcanic Ash Advisory Center (see Prata et al., 2018 for details). Note that in Prata et al. (2018) the risk indices were coloured as follows: 0 = not coloured, 1-3 = yellow, 4-6 = amber, 7-9 = red. Any further queries about the data may be sent to a.t.prata@reading.ac.uk or h.f.dacre@reading.ac.uk 6. REFERENCES -------------------------- Prata, A. T., Dacre, H. F., Irvine, E. A., Mathieu, E., Shine, K. P. and Clarkson, R. J. (2018) Calculating and communicating ensemble-based volcanic ash dosage and concentration risk for aviation. Meteorological Applications. ISSN 1469-8080 doi: https://doi.org/10.1002/met.1759.