ATLANT. DEEP-SEA EXPED. 1910. VOL. IJ PHYSICAL OCEANOGRAPHY AND METEOROLOGY 



51 



or variable currents. The observations will refer to water 

 masses with different mean temperatures wliich ;ire not 

 directly comparable l)y a study of the seasonal changes. 

 On the very same day quite different temperatures may 

 be observed at the same depth at different stations. The 

 spreading of the points on the mm. -paper is then too 

 great to allow of a somewhat certain construction of a 

 curve representing the seasonal variations. By means of 



Figs. 13 and 16 these stations from 1924 are marked * 

 and from 1925 A. The material of observations comprises 

 13 different e.xpeditions and 11 different years. The num- 

 bers which are inserted on the map give the dates of 

 observation, January 1st having been reckoned as 1 and 

 December 31st as 365. 



To begin with stations from the whole of the eastern 

 North Atlantic between 32' and 60' N were combined for 



12° 



11° 



Figs. 12. (Area B) and 13 (Area C). Comparison between tlie direct obser- 

 vations of temperature at 100 metres (upper part of the figures) and the 

 "temperature anomalies" calculated with deference to the salinities observed. 



the above-mentioned "temperature anomalies" we may, 

 however, to a considerable e.xtent reduce our original 

 observations so that tlie variations of currents are partly 

 eliminated. By help of the curve on p. 74* the "normal" 

 temperature corresponding to the salinity observed has 

 been found and subtracted from the temperature observed. 

 In the following we shall discuss the results obtained by 

 this mode of proceeding. 



The map Fig. 1 1 shows most of the stations which 

 have been used. South and southwest of Portugal some 

 stations taken with the "Albacora" in 1924 and 1925 

 could not be inserted in the chart for want of space. In 



the construction of curves representing the variations of 

 temperature at different levels during a year. Some gene- 

 ral differences appear, however, between the conditions 

 in the northern, middle and southern regions. The obser- 

 vations were, therefore, divided in 3 groups as shown in 

 Fig. II:— A: NW of Ireland, B: the Bay of Biscay and the 

 sea further west, and C: the area between Portugal, Morocco 

 and Madeira. In the two northern areas only stations 

 from places where the depth is over 1000 metres have 

 been taken into consideration, and in the southern area 

 only stations with a depth of 800 metres or more are 

 included. 



