Analysis of Frequency Trends in Amalgamated Peczely Macro-Synoptic Types (1971-2020) Characterising Continental-Scale Circulation Parallel to the Global Warming

Abstract

Macro-synoptic classification, based on spatial fields of sea-level pressure often meet application in applied climatology, weather forecasting and in air-pollution meteorology. One of these classifications was defined by Peczely (1957), establishing 13 original classes influencing actual weather in Hungary. These types, however, are of local concern and not appropriate for diagnostic analysis of continent-scale modification of circulation, related to the on-going global climate change. In the present study, new continent-scale circulation types are defined, based on frequent transition between the original circulation types, two cyclonic (Atlantic and Mediterranean) and two anticyclonic (Northward and Central-Southward) groups are defined, joining 3x3 and 1x4 original circulation types. Frequency trends of these amalgamated circulation types are established in the recent 50 years during which period a monotonical warming trend could be established in the mean near-surface temperature of the Northern Hemisphere. An important feature of these circulation trends is that the significant trends of the amalgamated types are of the same sign in all cases, although the signs of the trends are different for the different amalgamated types. Comparison of these significant 50-year trends with those derived from two 30 years periods, however, this comparison suggests that there is no simple universal relationship between the continent-scale circulation and the hemispherical mean temperature.

Keywords

• circulation types
• peczely
• europe
• climate change
• linear trends