Atmospheric Patterns Leading Major Avalanche Episodes in the Eastern Pyrenees and Estimating Occurrence
نویسندگان
چکیده
The occurrence of major avalanche episodes in the Eastern Pyrenees (NE Spain) is estimated by means of the Poisson and the negative binomial distributions, assuming that they are rare events. The differences observed in their spatial distribution along the seven regions in which Eastern Pyrenees have been divided, suggests us to look for spatial variations in the relationship between extreme avalanche episodes and synoptic patterns. Applying principal-component analysis procedure, atmospheric patterns at 500 hPa geopotential height leading major avalanches have been obtained. Looking at their pressure anomalies at 500 hPa, the relation of these patterns respect to the normal atmospheric conditions can be assessed.
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