Using a default of 0.05 for fine-ash fraction and a peak to mean ratio of 1 for ash-calculations following
Beckett, F.M.; Witham, C.S.; Leadbetter, S.J.; Crocker, R.; Webster, H.N.; Hort, M.C.; Jones, A.R.; Devenish, B.J.; Thomson, D.J. Atmospheric Dispersion Modelling at the London VAAC: A Review of Developments since the 2010 Eyjafjallajökull Volcano Ash Cloud. Atmosphere 2020, 11, 352. https://doi.org/10.3390/atmos11040352
Allowing manually change of fine-ash fraction in user interface to either a new value or to original default, i.e. taken from Mastin et al (2009b) Table 3.
Using a default of 0.05 for fine-ash fraction and a peak to mean ratio of 1 for ash-calculations following
Beckett, F.M.; Witham, C.S.; Leadbetter, S.J.; Crocker, R.; Webster, H.N.; Hort, M.C.; Jones, A.R.; Devenish, B.J.; Thomson, D.J. Atmospheric Dispersion Modelling at the London VAAC: A Review of Developments since the 2010 Eyjafjallajökull Volcano Ash Cloud. Atmosphere 2020, 11, 352. https://doi.org/10.3390/atmos11040352
Allowing manually change of fine-ash fraction in user interface to either a new value or to original default, i.e. taken from Mastin et al (2009b) Table 3.