Actual data compared with modelling
Could somebody clarify what data decisions are presently being made on?
From this thread I have gathered that the ash is not visible to the naked eye, except in very high concentrations. What levels of ash contamination are visible to satellite imagery?
Having got down to level below which it is not visible on satellite imagery, I presume everything else is based on computer modelling. The longer the eruptions continue, the further the ash spreads and the more complex the weather patterns have been to disperse the ash. Therefore the accuracy of the model will get gradually worse, because there is being little or no verification of the predicted data with measurement.
So I am assuming that once the ash is no longer detectable on satellite imagery, the accuracy of any other predictions is gradually getting less.
Have I totally misread the situation?
Phil