lOO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 70 



DISPROOF OF THE ASSUMPTION THAT THE OBSERVED TEMPERATURE 



VARIATIONS ARE DUE PRINCIPALLY TO VARIATIONS 



IN THE OCEAN CURRENTS 



Counter to the assumption that the variations in the surface tem- 

 perature of the North Atlantic Ocean depend mainly on the trans- 

 portation of colder or warmer water-masses along with the Gulf 

 Stream drift, tends the fact already mentioned, namely, if the sur- 

 face temperature in February in the middle of the North Atlantic 

 Ocean (30° to 39° west longitude) in comparison to that of the 

 most easterly part (10° to 19° west longitude) is low, then the sur- 

 face temperature on the coast of Europe near the Channel is high 

 as well as the air temperature over the northwest coast of Europe 

 at Hamburg and the yearly mean height of the water in the North 

 Sea and in the Baltic Sea. If, however, the surface temperature 

 in the middle part of the North Atlantic Ocean is high in rela- 

 tion to that of the eastern part, all this is reversed. Obviously 

 another cause must produce this result and we shall return to this 

 later. 



Opposed to the assumption that the minimum in the years 1903 

 and 1904 depended only on the transportation of cold water with 

 the Gulf Stream is the circumstance that this minimum, particularly 

 in the year 1904, extended over so great a part of the earth. In 

 the first place we find it not only over the whole of the region 

 of the Atlantic Ocean investigated by us, but also yet further 

 south near the equator, as shown in the Dutch fields (pi. 15, fields 

 19 to 20) where there was a minimum which agreed completely 

 with ours and which also occurred in the yearly temperature (see 

 fig. 39 and pi. 28) . In the western Danish fields north of 50° north 

 latitude, shown in figure 33, and also on the equator between 0° 

 and 1° north latitude»and 29° to 32° west longitude, as we shall 

 see later, we find the same minimum in the yearly temperature 

 (see fig. 60, icurve IXb). In the Indian Ocean also there appeared 

 a minimum in the year 1904, as is shown by the Dutch records for 

 the 10° squares (see fig. 62, curve VIII). 



Not only in the ocean was there a minimum in February, March- 

 April, and the whole year 1904, but also in the atmosphere there 

 was a minimum over a great region of the earth, particularly 

 marked in the tropics, and further appearing^ in the average tempera- 

 ture fo'r the year on the whole earth (see fig. 60) of which we 

 shall speak later. We must therefore believe that there was a more 

 general cause at work, for it is not possible that a mere local trans- 

 portation of relatively cooled water into the Atlantic Ocean could 

 have produced such general effects. 



