ISSN:
1420-9136
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Summary The Southern Oscillation in air pressure may be described primarily as an air pressure balance whose scales are centred near Djakarta (Indonesia) and near Easter Island (South Pacific Ocean) respectively. A synoptic station was established at Easter Island July 1, 1949. 1) The 8 twelve-monthly air pressure values of Djakarta and Easter Island from the period July 1949 up to July 1957 have been correlated with the simultaneous air pressure values at 289 stations throughout the world; 2) The 7 twelve-monthly air pressure values of Djakarta and Easter Island from the period July 1949 up to July 1956 have been correlated with the simultaneous air pressure values at 65 grid points in North Asia and from the period July 1950 up to July 1957 with simultaneous air pressure values at 32 grid points in Africa; 3) At least 5 twelve-monthly air pressure values of Djakarta and Easter Island have been correlated with simultaneous air pressure values at 159 grid points between latitudes 20° and 60° S (Southern Hemisphere Project, Weather Bureau, Pretoria). The latter coefficients obtained, being less reliable, have been used only indicatively. The 545 correlation coefficients have been plotted on world charts and isopleths of the correlation coefficients with the values −0.9,; −0.7; −0.4; 0; +0.4; +0.7 and +0.9 have been drawn (Fig. 1 and 2). The patterns of the isopleths on both maps are very much alike. This is due, of course, to the fact that the coefficient of correlation between Djakarta and Easter Island air pressure deviations reaches a value as high as −0.93. From these pictures may be inferred that the Southern Oscillation acts for the greater part as a stationary wave and for the rest as a progressive wave. Another prominent feature of the Southern Oscillation, shown by the pictures, is that the Easter Island scale is meridionally developed, whereas the Djakarta scale is mainly zonally developed, especially along the equator. It is shown to be very probable that the arctic and antarctic regions both cooperate with the Djakarta region, thus stressing an undeniable overall zonal symmetry of the two patterns. A first impression is obtained of the kind of encroachment of the antarctic circulation on the Southern Oscillation. The well detailed patterns in the northern moderate and high latitudes call up the idea of the planetary waves in the zonal current which normally flows through these latitudes and the question is raised whether blocking action is stimulated when the Southern Oscillation is well developped. Similar indications are obtained from the still rather provisional and rough patterns in the southern moderate and high latitudes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01997657
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