Spatial evaluation of volcanic ash forecasts using satellite observations

Atmospheric Chemistry and Physics

N. J.Harvey¹  H. F.Dacre¹ 

DOI  :  10.5194/acp-16-861-2016

学科分类：大气科学

来源: Copernicus Publications

【 摘 要 】

The decision to close airspace in the event of a volcanic eruption is basedon hazard maps of predicted ash extent. These are produced using output fromvolcanic ash transport and dispersion (VATD) models. In this paper thefractions skill score has been used for the first time to evaluate thespatial accuracy of VATD simulations relative to satellite retrievals ofvolcanic ash. This objective measure of skill provides moreinformation than traditional point-by-point metrics, such as success indexand Pearson correlation coefficient, as it takes into the account spatialscale over which skill is being assessed. The FSS determines the scale overwhich a simulation has skill and can differentiate between a "near miss"and a forecast that is badly misplaced. The idealized scenarios presentedshow that even simulations with considerable displacement errors have usefulskill when evaluated over neighbourhood scales of 200–700 (km)². Thismethod could be used to compare forecasts produced by different VATDs orusing different model parameters, assess the impact of assimilatingsatellite-retrieved ash data and evaluate VATD forecasts over a long timeperiod.

【 授权许可】

Unknown