4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 09 



The Parana River drains the interior of South America hetween 

 about 15° S. and 30° S. The river heights used were those measured 

 at Rosario, Argentina, near the mouth of the river. The mean annual 

 height for each year from 1900 to 1932 is given in column (2) of 

 table I. The variations of height are believed to form a good index 

 of the variations of rainfall over central South America, because 

 there is no snowfall or ice to retard the flow of water into the river. 

 The correlation between the rainfall of the interior of the United 

 States and the variation in height of the Parana River is found to 

 be +.55 ±.08. 



It was shown in a preceding paper* that the annual variations of 

 pressure at San Diego are similar to those at Buenos Aires. 



In figure 2 a comparison is made between the rainfall of the interior 

 of the United States and the rainfall of Australia. The rainfall of 

 the United States was obtained as previously described. The rain- 

 fall of Australia is expressed in percentages of Australia covered 

 by areas of rainfall in excess of the normal. These data were obtained 

 from the Rain Map of Australia, 1931 and 1932, published by the 

 Commonwealth Meteorologist and are given in column (3) of table i. 

 In this case there is an inverse relationship — that is, when the rainfall 

 in the United States is low, that in Australia is high, and vice versa. 

 For this reason the curve of Australia is inverted, the higher values 

 being plotted downward. The correlation value is —.66 ±.08. 



In comparing the two sets of curves, it is seen that every marked 

 depression in the rainfall in the interior of the United States was 

 accompanied by low water in the Parana River except in 1930 and 

 was coincident with a marked excess of rainfall in Australia, except 

 in 1924. 



In figure 3 is shown a comparison of the annual mean pressures at 

 Batavia in the Indian Ocean with the annual mean temperatures at 

 Santiago, Chile. There is clearly a similarity between them, showing 

 that they tend to oscillate in the same way. The correlation between 

 the two for 64 years, 1866 to 1930, is r=.43±.03. An even closer 

 relation is found between the pressure in the Indian Ocean as observed 

 at Colombo, Ceylon, and that at Santiago, Chile. The correlation for 

 the 29 years, 1871 to 1902, is r=— .68±.o8, and for the 28 years, 

 1903 to 1930, it is r= —.61 ±.08. In other words, the pressure oscil- 

 lates oppositely in the two regions except for occasional breaks in 

 the sequence. 



Many similar instances have been pointed out by others. Bland ford, 

 Teisserenc de Bort, Hildebrandsson, Lockyer, Mossman, Arctowski, 



' Smithsonian Misc. Coll., vol. 78, no. 4, p. 43, 1926. 



