Fluctuations in Arctic climate with biological productivity of the English Channel 219 



The areas around the Faeroe-Iceland Ridge and the Denmark Strait are sinks in every 

 sense of the word. Consequently, not until the argument is geared to a thermodynamic 

 source can it be fully satisfactory. 



A chain of hypotheses has been constructed to link fluctuations in Arctic climate 

 with fluctuation in the biological productivity of the English Channel. The author 

 is under no illusions as to their vulnerability to attack from many directions. He can 

 hope only that, by offering a target, something more substantial may emerge. 



There is climatic evidence in support of the hypotheses. 



Smed(1947, e^j'e^.) has collected and summarized all the records of surface tempera- 

 ture which have been collected in the North Atlantic. Fig. 2 shows the areas into which 

 he has divided the North Atlantic. His areas B, C, D are those in which we are most 

 interested. A series of cold winters was experienced in the 'teens of this century, and 



58* 



67'- 



63*- 



60*- 



SC- 



30* 



20* 



10* 



1921 -0.8(18) 



B 



1920 -0.3(27) 



1921 -0.8(53) 



1920-0.4(6) 

 1921 -1.5(16) 



1920 -0.5 (15) 



1921 -0.4 (64) 



1920 -3.0( 



1921 -2.0(36) 



1920 -0.6 (2) 



1921 -0.7(63) 



I 



0.5(21 

 1921 -1.6(24 



H 



1920-2.0(12) 

 1921-0.6(78 



6T* 



ROCKALL 



1920-2.0(9) 

 1921 -1.2 (36) 



63* 



60* 



50* 



40° 



30' 



20' 



lO* 



50* 



Fia 7 Northern North Atlantic Average departures of sea surface temperatures (C) from long 

 Term meam ,n Se Itths of Apnl 1920 and 19^1. The number of available observat.ons averaged .s 



shown in brackets (alter Smed). 



particularly in 1918, 1920 and 1921. In the same Figure the departures Irom ihc long 

 term average of the sea temperatures in April, 1920, and April, 1921, are presemed^ 

 These were the culmination of a series of cold winters when a great amount ot North 

 Atlantic bottom water must have been formed. . ^ . „ 



Air temperatures between 60^ and 70° N have been recently summarized by Brown 

 (1953) Fig 3 shows the area studied divided in Marsden squares. Unfortunately, 

 for squares 220 and 221 (in which we are most interested) there are msuflicenl data 

 for evaluating means. His decadal means for areas 217A and B and 218A and B are 

 shown in Fig. 4. It will be seen that the decade 1910-1919 in December-March was 



