NO, 



4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC I37 



P-I-II, L-II to L-V) and a three-year period (see particularly 

 fig. 55, curves III, IV, and VII to IV; fig. 56, curves P-VII, 

 VIII, P-III-IV). These three-year periods agree with the cor- 

 responding periods of the prominences quite definitely. See for 

 example in figure 56, curves L-V and L-VI compared with R, for 

 the prominences, as obtained by the Osservatorio del Collegio 

 Romano. As we have mentioned above, the curves show a certain 

 similarity to the sun spot curve which points toward an eleven- 

 year period. In order to bring these periods distinctly to view, we 

 have taken the yearly means for the calendar years of temperature 



Figure 57. Three-year smoothed curves of surface temperature. I : for the 

 Danish field 20° to 29° west longitude 50° to 57° north latitude. II: for the 

 Danish field 30° to 39° west longitude 50° to 53° north latitude. Ill : for 

 Petersen's stations III to VIII, 22° to 46° west longitude. IV: for the 

 Dutch 10° square from 5° to 14° north latitude 25° to 34° west longitude. V : 

 for Liepe's most southerly stations VII to VII at 2° to 8° latitude. VI : 

 for the equatorial field at 0° north latitude, 29° to 31° west longitude, see also 

 figures 55, curve VII. VII : for the two Dutch fields in the Indian Ocean from 

 0° to 9° north latitude 70° to 89° east longitude, see also figure 55, curves X 

 and XI._ M: for the degree of disturbance of the three magnetic elements 

 in Potsdam. This curve is given with its scale at the left and the curve 

 inverted. S : for the relative sun spot numbers. This curve is given with its 

 scale on the right, curve inverted. 



for the different fields and have subjected them to three-years' 

 smoothing. 



In figure 57 we give in graphical form the results obtained in 

 this way for temperature values of fields in the middle part of the 

 North Atlantic. These include the Danish fields 20° to 29° west 

 longitude and 30° to 39° west longitude, curves I and II; Peter- 

 sen's stations III to VIII combined into one curve III ; the Dutch 

 10° squares at 5° to 14° north latitude and 25° to 34° west longitude, 

 curve IV; Liepe's stations VII-VIII, shown in curve V; the equa- 

 torial field of the International Central Bureau 0° north latitude, 29° 



10 



