Interactive comment on “Model-based aviation advice on distal volcanic ash clouds by assimilating aircraft in-situ measurements” by G. Fu et al

The article represents a nice study treating the application of an Ensemble Kalman Filter on the prediction of volcanic ash plumes distal to the emission source, exploiting the observational information of aircraft-performed mass concentration measurements. This is innovative in terms of volcanic ash dispersion forecast improvements for aviation advice because it exploits real observational in-situ data by assimilation. The authors discuss the results as well as validate the assimilation performance using independent measurements. However, especially the discussion of assimilation impacts on subsequent ash dispersion predictions and thereon based aviation advices suffer from imprecise definitions of influenced areas. Further, some stated terms, interpretations,