Analysis of hourly precipitation characteristics in Kraków, southern Poland, using a classification of circulation types

摘要

This paper investigates the relationship between maximum precipitation in Krako ´w and typesnof atmospheric circulation in southern Poland, as classified by Niedz ´wiedz ´ . Three characteristicsnwere used to define this relationship: maximum precipitation (Pmax), its duration (d) andnprobability of exceedance ( p). The input data came from Krako ´w’s uniquely long andnhomogenous pluviographic record spanning the period 1886–2007. Hourly precipitation valuesnfor the maximum precipitation events were identified and arranged in 1–24 hour intervals. Theynwere then processed using the generalized extreme value (GEV) distribution to produce quantilesnof maximum precipitation totals in each of the intervals and broken down by the correspondingncirculation type. Differences between the development mechanisms are manifested innrelationships between precipitation characteristics and their measure of randomness,ni.e. exceedance probability. This paper demonstrates that maximum precipitation events dependnon their duration d and atmospheric circulation. The maximum short-duration (one-hour) eventsnoccur primarily in either of two circulation types: (i) cyclonic with advection from the east andnfrom the southeast or (ii) low-pressure centre and cyclonic trough. Maximum long-durationnprecipitation events (24 hour), on the other hand, occur in the cyclonic type of circulation withnadvection from the north and from the northeast.