NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 1 5 



below it is forced up on the left side of the stream and follows on 

 southward with the cold surface water. On the other side of this 

 cold " wedge " there goes according to our chart a warmer oppos- 

 ing stream to the no'rtheast and north. These hypotheses are 

 strengthened by the march of the isotherms. 



We do not know with certainty the direction of the separate 

 parts of the currents further eastward in their course through 

 the Atlantic, and the current paths and eddies which we have indi- 

 cated there must be regarded as somewhat hypothetical. 



Figure 7 shows the distribution of the surface temperatures in 

 February in the North Atlantic Ocean according to the represen- 

 tation given in " Atlantic Ocean " published by the Deutschen See- 

 warte in Hamburg, 1902. The figure shows also the mean tempera- 

 tures which we have found for the three February decades from 

 1900 to 19 10 for 10° fields of longitude in the region Portugal to 

 Azores, and also for the similar 10° fields of the route Channel- 

 New York. The mean of the latter is found from temperature 

 values of the 2° fields previously mentioned which occur in the 

 10° intervals of longitude between 10° and 20° west longitude and 

 between 20° and 30° west longitude. There is clearly a good agree- 

 ment between these values and the ones represented by the isotherms 

 published by the Seewarte. However, we may remark that our 

 values for the eleven-year period 1900 to 1910 are somewhat lower 

 in the eastern part of the ocean than those indicated by these 

 isotherms. 



We have also given the observed mean temperatures for Febru- 

 ary (1900-1910) for the 10° fields along the Danish routes north 

 of 50° north latitude. They are mostly considerably lower than 

 those corresponding to the isotherms. The isotherms for 10°, g°, 

 8° and 7° C. should accordingly probably be moved somewhat fur- 

 ther to the southeast between 40° and 10° west longitude. 



On this chart (repeated in pi. i) we give the above mentioned 

 mean temperatures for the time interval 1900 to 1910 for each of 

 the investigated 2° fields (where there were sufficient observations) 

 on the route Channel-New York as well as the corresponding mean 

 temperatures in the 10° fields in the region Portugal-Azores. 

 Based upon these mean temperatures, we give also the isotherm 

 for 8° C. and also those for each full degree between 10° and 

 16° C. As the reader will see, these do not differ in their course very 

 much from the isotherms which appear on the charts issued by 

 the Seewarte. In figure 5 we have endeavored to draw an isotherm 



