304 



DEPTHS OF THE OCEAN 



but, of course, that is too short a period from which to draw 

 definite conclusions. Anyhow, these preHminary results point 

 to possibilities of no little importance, and we may in the future 

 be able to predict, months beforehand, whether the coming 

 winter will be warmer or colder than the normal. Many 

 similar relations could be pointed out between the conditions in 

 the sea and facts of interest bearing upon our daily life, but the 

 above examples give an indication of the problems to be faced 

 in modern oceanography. 



The Atlantic current flowing northwards over the Norwegian 



Sea, which in our waters 



/SOO /so/ t902 /S03 /S04 /SOS . ' , >-> i r 



IS also called the Gulf 

 Stream, is thus subject to 

 considerable variations in 

 temperature and total 

 amount of heat. This cur- 

 rent is, however, a mixture 

 of water from the Atlantic 

 proper with water from the 

 northern currents penetrat- 

 ing intothe Norwegian Sea, 

 north of the Faroe Islands, 

 and the character of the 

 " Gulf Stream " will de- 

 pend on the conditions of 

 mixture, and on the indi- 

 vidual temperature of each 

 of these currents, factors of 

 It 

 is highly probable that the 

 Gulf Stream of the Atlantic also shows annual variations, 

 and, though they may not be of much importance in their 

 effect on the small branch in the Norwegian Sea, they may 

 prove to be of great climatological significance for the 

 countries on both sides of the Atlantic Ocean ; a thorough 

 study of this current in the immediate future is therefore 

 looked forward to with great expectations. That there are 

 large annual variations in the caloric conditions of the huge 

 water-masses of the North Atlantic was suggested by the 

 observations of the "Challenger" nearly forty years ago, and 

 has been confirmed during the recent cruise of the " Michael 

 Sars," these two vessels having made investigations in the 



Fig. 209. 

 I. and II. , the annual variations in the amount of 

 heat in the "Gulf Stream" (Sognefjord section, 

 May); III., variations in the air- temperature of which WC knOW little. 



Norway (November to April). 



