Quantitative aspect in circulation type classifications – an example based on evaluation of moisture flux anomalies.
Abstract
The paper is motivated by the effort to add the quantitative aspect into the process of classification of circulation types and to enable the comparison of various regions from the viewpoint of synoptic-dynamical causes of hydro-meteorologically extreme events. Three-day grid-related means of zonal and meridional components of moisture flux were used as the criterion for the suggested circulation type classification.
The method was applied to heavy rain events which occurred in warmer half-years 1958-2002 within selected Central-European river basins. Central-European extreme rain events were accompanied with extra significant moisture flux anomalies.
We detected four regions with different circulation types responsible for heavy rains and demonstrated a close relation between dominant circulation type and the seasonal distribution of heavy rain events in the regions.