432 APPENDIX V 



depth was thereby cooled on an average 2° C. This zone of 

 water weighs about 1'5 trillion kilogrammes, and the quantity of 

 warmth given off thus corresponds to about 2 '5 trillion great 

 calories. 



It has been calculated that the whole atmosphere of the earth 

 weighs 5*27 trillion kilogrammes, and it will require something 

 over 1 trilhon great calories to warm the whole of this mass of 

 air 1 C. From this it follows that the quantity of warmth 

 which, according to our calculation, is given off to the air from 

 that part of the South Atlantic lying between lats. 15° and 35° S., 

 will be sufficient to warm the whole atmosphere of the earth 

 about 2° C, and this is only a comparatively small part of the 

 ocean. These figures give one a powerful impression of the 

 important part played by the sea in relation to the air. The sea 

 stores up warmth when it absorbs the rays of the sun; it gives off 

 warmth again when the cold season comes. We may compare 

 it with earthenware stoves, which continue to warm our rooms long 

 after the fire in them has gone out. In a similar way the sea 

 keeps the earth warm long after summer has gone and the sun's 

 rays have lost their power. 



Now it is a familiar fact that the average temperature of the air 

 for the whole year is a little lower than that of the sea; in winter 

 it is, as a rule, considerably lower. The sea endeavours to raise 

 the temperature of the air; therefore, the warmer the sea is, the 

 higher the temperature of the air will rise. It is not surprising, 

 then, that after several years' investigations in the Norwegian Sea 

 we have found that the winter in Northern Europe is milder than 

 usual when the water of the Norwegian Sea contains more than 

 the average amount of warmth. This is perfectly natural. But 

 we ought now to be able to go a step farther and say beforehand 

 whether the winter air will be warmer or colder than the normal 

 after determining the amount of warmth in the sea. 



It has thus been shown that the amount of warmth in that part 

 of the ocean which we call the Norwegian Sea varies from year to 



