Objective classification of atmospheric processes for the East European region

Abstract

The article describes the objective classification, involving the automated systems application to section the atmospheric processes by types. The objective of typing is to split a collection of objects of a certain sample according to the maximum-distance-separable groups. The basis for objective classification includes several methods: correlation, cluster analysis, nonlinear methods, neural network method, etc. One of the analysis methods for the characteristics of synoptic processes is typing, or the classification of synoptic processes by types, which allows finding common features of development of atmospheric processes in a large variety of synoptic situations. The objective of typing is to split a collection of objects of a certain sample by maximum-distance-separable groups. Since the beginning of the XIX century, when the classification of synoptic processes was introduced to the practice of weather forecasting, there were published a large number of works that differ in specific methodological approaches, in a number of selected types of weather, etc. Currently, only on the territory of Europe, according to various estimates, researchers allocate from 4 to 40 types of atmospheric processes and account for up to 209 subtypes, 84 % of which is obtained by analyzing the data of surface atmospheric pressure, geopotential heights and wind characteristics. On-scale data from 6 to 12 hours (9 %), daily (84 %) and monthly data(7 %) are used as an output information. The spatial range varies from mesoscale (5% of classifications), regional (3 %), on an individual nationwide scale (20 %), as part of the continent (22 %) and the continent as a whole (50 %) The second half of the XX century and the beginning of XXI century are characterized by high rates of changes in climatic and circulation conditions. An occurrence of rare weather extremums is a manifestation of the transition state of the atmosphere and its instability. Often regional changes have more significant variations than global. Therefore, progress, in the understanding of current trends of climate change, is impossible without taking into account spatiotemporal dynamics of atmospheric processes. The author considers the main principles of GWL classification and investigates regional characteristics of synoptic processes in the territory of Europe based on the characteristics of the surface baric field and displacement trajectories of the main baric systems. The purpose of this paper is to explore one of the most popular classifications for the European region and to establish the possibility of its further application to the territory of Ukraine. Research methods: a statistical description of the synoptic types for Europe for the period from September 1957 up to August 2002. Results of the study confirm the fact, that the addressed classification is aimed at creation of seasonal and interannual forecasts of synoptic processes and works better in the central, western and southern directions of Europe.