Summary
Using annual and monthly values of the local zonal index, we study the circulation change during the past hundred years for the area A (20°W–10°E) and area B (10°E–40°E).
For the area A the results are: 1) During the subperiod (1873–1902) blocking systems were predominant and westerly type of circulation was less frequent. 2) For the subperiod (1903–1932) an abnormal situation prevailed in 80% of the years, towards the direction of W zonal flux. 3) The third subperiod (1933–1972) was characterized from the point of view of intensity of zonal flux as intermediate.
For the area B showed that the prevailing circulation was actually meridional or “Low Index”. Also for the area B the easterly zonal circulation was 26%.
Zusammenfassung
Mit Verwendung von Jahres- und Monatswerten des lokalen Zonalindex werden die Zirkulationsänderungen in den letzten hundert Jahren im Gebiet A (20°W–10°E) und im Gebiet B (10°E–40°E) untersucht.
Für das Gebiet A hat sich ergeben: 1. In der Teilperiode 1873–1902 waren blockierende Systeme vorherrschend und der Typ einer westlichen Zirkulation kam weniger oft vor. 2. In der Teilperiode 1903–1932 herrschte in 80% der Jahre eine abnormale Situation in Richtung zu zonaler Westströmung hin vor. 3. Die dritte Periode (1933–1972) war vom Gesichtspunkt der Intensität durch zeitweise zonale Strömung charakterisiert. Für das Gebiet B zeigte sich, daß die Zirkulation entsprechend einem niedrigen Index vorherrschend meridional war. Im Gebiet B kam eine zonale östliche Strömung in 26% der Jahre vor.
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References
Chang, Jeu Hu: Atmospheric Circulation Systems and Climates. Oriental Press, p. 149. 1972.
Lamb, H. H.: British Isles Weather Types and a Register of the Daily Sequencies of Circulation Patterns 1861–1971. Geophys. Memoirs, No. 116, London, 1972.
Lamb, H. H., Collison, P., Ratcliffe, R. A. S.: Northern Hemisphere Monthly and Annual Mean-Sea-Level Pressure Distribution for 1951–56, and Changes of Pressure and Temperature Compared with Those of 1900–39. Geophys. Memoirs, No. 118, London, 1973.
Lamb, H. H., Johnson, A. I.: Secular Variation of the Atmospheric Circulation Since 1750. Geophys. Memoirs No. 110, London, 1966.
Makrogiannis, T. J., Bloutsos, A. A., Giles, B. D.: Zonal Index and Circulation Change in the North Atlantic Area, 1873–1972. J. Climatology2, 159–169 (1982).
Namias, J.: The Index Cycle and Its Role in the General Circulation. J. Met.77, 130 (1939).
Rossby; C. G., et al.: Relation between Variation in the Intensity of the Zonal Circulation of the Atmosphere and the Dispacements of the Semipermanent Centers of Action. J. Marine Res.2, 38 (1939).
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Makrogiannis, T.J. Local zonal index and circulation change in the European area, 1873–1972. Arch. Met. Geoph. Biocl., Ser. B 34, 39–48 (1984). https://doi.org/10.1007/BF02275673
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DOI: https://doi.org/10.1007/BF02275673