On the Surface Temperature of JVorth Sea and North Atlantic. 23 



Norwegian Sea, as compared with the conditions along the meridian 

 of 15° W., will, in the same high latitude, be considerably perturbed 

 by this anomalous condition of the standard of comparison. This is 

 at once apparent in our chart. We see from the latter that the 

 whole basin of the North Sea, and all the waters of the liritish coasts 

 are notably cooler than the mid-Atlantic waters in corresponding 

 latitudes, and tlie relative cooling is nowhere less than half a degree 

 centigrade. In other words, an isanomaly of — '5° runs from the neigh- 

 bourhood of Bergen round the west coasts of Scotland and Ireland, 

 and is continued southward at some considerable distance from the 

 French coast. It is followed at no great distance by an isanomaly 

 of — 1° C, which line, however, visibly bends into the North Sea, the 

 Irish Sea, and slightly into the mouth of the English Channel. In 

 the greater part of the North Sea, the Skagerrack, the Irish Sea, and 

 the English Channel, the anomaly lies between —1° and —2" C. 

 Off the east coast of England and Scotland, the west coast of Den- 

 mark, and a considerable stretch of the southern and eastern North 

 Sea, the anomaly runs from — 2° to — 3^ C, and it exceeds — 3° C. in a 

 small area in the Cirerman Bight, and again in the Cattegat. Doubt- 

 less as we approach and enter the Baltic, the anomaly will be found 

 to increase greatly. 



In the Norwegian Sea, between Shetland and Faroe on the one 

 hand and the coast of Norway on the other, the anomaly is a positive 

 one, the mean temperatures tending to be higher than those of the 

 Atlantic along our standard meridian of 15° W. This phenomenon, 

 over which w^e need not spend time, is in part due to the warm waters 

 of the Gulf Stream Current, which actually give to this region (or 

 part of it) a mean temperature above what is properly due to such 

 latitudes ; and in part is due (as we have already indicated) to the 

 fact that in the corresponding part of our standard meridian, the 

 waters are unduly cooled by the neighbourhood of the great Ice- 

 landic land-mass, and by the cold current which eddies round the 

 east coast of Iceland from the north. 



The range of temperature between maximum and minimum, that 

 is to say, the amplitude of the fundamental sine-curve, varies in a 

 very regular manner in our area, as has already been said. The am- 

 plitude is largest in the German Bight and Cattegat, where the total 

 range is over 14°, the half range (which is represented in our chart, 

 Fig. 6) being over 7°. From this region the values steadily diminish 

 as we pass on the one hand towards Shetland and Faeroe and on the 

 other towards the mouth of the English Channel. In all cases as we 

 enter the narrow seas from the ocean (that is to say in the Channel, 

 at the northern opening of the North Sea and off both the north and 

 south of Ireland), we see the curves of equal amplitude sagging inwards ; 

 that is to say the low amplitudes characteristic of the open ocean tend 

 to show their influence for some distance into the narrow seas. 



This chart of amplitudes is so simple in itself that we do not gain 

 very much by transforming it into a chart of isanomalies. However, 

 I have made such a chart (Fig. 7), for the sake of uniformity with the 

 others, to show as in the other cases how this phenomenon of am- 

 plitude differs throughout our area from the conditions which obtain 

 along the meridian of 15' W. It will be seen that we get an ex- 



