266 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 70 



XIII. CONCLUSION 



The point of departure in these investigations was the wish to 

 investigate more closely some of the yearly temperature variations 

 in the North Atlantic Ocean. We have seen that such variations 

 are present and that they are very considerable and extend over 

 great regions in common. They can be ascribed in greater part 

 to the action of the air pressure distribution, that is to say, the 

 winds. In order to understand the occurrence and the nature o'f the 

 variations, meteorological variations must therefore be closely 

 studied. These can be understood only when the atmosphere as a 

 whole is investigated, and we are therefore led to make a very wide 

 investigation. 



Hitherto these extensive investigations have shown us that dif- 

 ferent groups of regions vary intact in a definite direction, while 

 another group of regions varies in an opposite sense, and that again 

 still other regions show transition phenomena, partly on account of 

 phase displacements and partly on account of mixed relationships 

 to the primary groups. All this gives us a variegated picture of the 

 meteorological fluctuations, but out of this same variegated picture 

 we find also by a proper analysis the influence of the variations in 

 the solar activity which in all probability make themselves felt first 

 in the higher layers of the atmosphere and thereby produces dis- 

 turbances which again introduce changes in the lower layers. Such 

 dynamic changes will take dififerent courses in respect to the tem- 

 perature, cloudiness, precipitation, etc., at different stations of' 

 the earth. But it seems possible by a thorough evaluation of avail- 

 able observational material to work out sure and general rules to 

 cover the phenomena. 



The present work is to be regarded only as an introduction to 

 such more thorough investigations, and we must postpone a clarifi- 

 cation of many of the questions raised here to later publications. 

 Among them is the regulating action which the thermal condition 

 of the ocean exercises upon the air circulation and the air tem- 

 perature. 



