NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 265 



sun spots and prominences, as figures 69, 88, 89, and others. For 

 example, in figure 88 we see that the eleven-year period in the promi- 

 nence curve comes out very clearly. The reader will see, however, 

 that the three periods from 1878 to 1913 are very differently formed. 

 In the first of these three periods there was a very great average 

 number of prominences, in the next considerably less, and in the 

 last relatively very few. The smoothed curve for the prominences 

 shows therefore a clear decrease for this time interval of thirty-five 

 years. It is plainly a part of a secular period in the solar activity. 

 It appears that a similar sinking or corresponding rise occurred in 

 several of our meteorological curves. We have already remarked 

 that the temperature amplitude in Wellington (fig. 71) and the air 

 pressure in Batavia (fig. 69) showed such changes. A direct or 

 inverted agreement between the solar and terrestrial phenomena 

 with respect to very long periods is indicated by still other curves. 

 So, for example, in the curve for the temperature amplitude of 

 North America (fig. 88 and also fig. 89) particularly in the Pacific 

 states, but also in the Gulf states and in the inner states, the ampli- 

 tude has on the whole during the three above mentioned eleven-year 

 periods gradually become less, as well also as the air temperature 

 itself on the west coast of the United States (fig. 64 curve I). Other 

 examples could be cited which point to such secular changes in the 

 meteorological phenomena in correspondence with solar changes. 



CLOSE RELATION BETWEEN THE VARIATIONS IN SOLAR ACTIVITY 

 AND IN METEOROLOGICAL ELEMENTS. 



As a general result of our investigations we can here only remark 

 that certainly a very close relation exists between variations in the 

 solar activity and variations in the meteorological phenomena of 

 the earth. Even short interval variations in the radiation of the sun 

 are shown very distinctly in our meteorological phenomena and in 

 the surface temperature of the ocean. They act through variations 

 of the air pressure distribution, but the expression on the earth may 

 take different directions according to conditions, running inverted 

 to the solar variations or parallel to them. 



This close dependence between the variations of the solar activity 

 and the variations of the meteorological phenomena is shown not 

 so much by the general correlation of our curves of figures 95 and 

 96 as by the sudden and extraordinary change of character which 

 all of these curves of the solar and the terrestrial phenomena present 

 in the middle of the decade of the 90's. 

 18 



