11. Arctowski — About Climatical Variations. 305 



Art. XXIV. — About Climatical Variations / by Heneyk 



Arctowski. 



Some striking correlations have been found between the 

 temporary climatic anomalies of far distant regions of the 

 globe. To recall attention to the discoveries made, it will be 

 sufficient to mention the names of Blanford, Woeikow, Hilde- 

 brandsson, Pettersson, Meinardus, Kremser, Lockyer, Bigelow, 

 Merecki, Mossman, and others. Now let us suppose an anom- 

 aly at two correlated centers of action of our atmosphere, e. g. 

 at the Icelandic low pressure center and the high pressure area 

 of the Azores. Evidently, if the barometric gradient between 

 these two centers of action is increased during a certain lapse 

 of time, the atmospheric circulation — and, therefore, the distri- 

 bution and quantity of rainfall — will vary in Western Europe 

 as well as in the Northeastern States and Canada. But what 

 are these variations for a given variation at the centers of 

 action ? 



As simple as this question seems to be, no serious attempt 

 toward its solution has ever been made. And the same may 

 be said about the other centers of action of atmospheric circu- 

 lation. It is true that some researches of Teisserenc cle Bort, 

 Hann, Poincare, Garrigou-Lagrange, and Exner may be men- 

 tioned, but the systematic work on the inter-action of the varia- 

 tions at the centers of action remains to be made. 



Let us consider for a moment another question : does the 

 temperature of our atmosphere remain constant from year 

 to year, or from a period of a given number of years to the 

 following period ? 



We have to admit, of course, that all the climates, all over the 

 world, have been very much warmer during certain geological 

 periods. We know also perfectly well that during the Pleis- 

 tocene ice age the temperature at the earth's surface was 

 very much lower than at present, and that similar important 

 climatic variations have produced ice ages during different geo- 

 logical periods. But how about the climates of historic times, 

 or the climates of, let us say, the last century or the last decade 

 of years ? 



Certain periodicities of climatic variations have been advo- 

 cated, discussed, contradicted, and may finally be admitted or 

 rejected according to personal opinion. This is particularly 

 the case of the 19-year period of Russell and the 35-year period 

 of Bruckner. 



A simpler periodicity is the sunspot cycle correlation. Long 

 ago, Koppen demonstrated the complexity of the phenomenon, 

 since he found that the variation is direct under certain lati- 



Am. Jour. Sci.— Fourth Series, Vol. XXXVII, No. 220.— April, 1914. 



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