1901] The Hydrography of the North Ocean. 21 



Remarks on the observations. 



In the preeeding tables is given a series of observations, which 

 in some degree contribute to the knowledge of the variations in the 

 superficial extent of the Gulf Stream. Dr. Peteemann (1870) has 

 shown the annual horizontal variations in the Gulf Stream. In 1892 

 the Swedish hydrographers Petteesson and Ekman showed that in 

 Skagerack variations were goirig on in a ' vertical direction too. 

 The ocean water was in summer at a higher level than in winter. 

 The same level dnference was afterwards observed in the Norwegian 

 fjords by dr. Hjoet and others. — There are, however, in the Gulf 

 Stream variations of another character. Prof. Petteesson says (6, 

 p. 16): „Ausser dieser jahrlichen Periode zeigt der Golfstrom auch 

 aperiodische Schwankungen." The observations of the Tromsø cap- 

 tains plainly illustrate the latter fact, and show that there is a 

 great scope between the limits of variation. 



Before I enter into a closer discussion of the facts given in 

 this paper, I will shortly mention some other observations of later 

 years, which are pointing at a considerable difference in the extent 

 of the Gulf Stream water. 



When Mr. Andeée in June 1896 was såiling along the west 

 coast of Spitsbergen, he was much delayed by ice, but the next year 

 the same ocean field was already at the end of May free from ice. 

 Petteesson and Ekman give the following explanation (6, p. 7): 

 „Im Allgemeinen war der Sommer 1897 ausgezeichnet durch eine 

 ausserordentlich starke Entwicklung des Golfstroms im nordlichsten 

 Nordmeer." In the summer of 1898 a German and a Swedish 

 expedition were in the Spitsbergen waters. 



Romee and Schaudinn say about the conditions mentioned (7, 

 p. 54): „Die ganzen Stromungsverhaltnisse des vorigen Sommers 

 waren entschieden eigenartig. Der Golfstrom sandte seine Verzweig- 

 ungen nm ganz Spitsbergen. Seine aussersten Aeste trafen wir 

 noch nordlich des 81. Grades, womit natmiich die aussergewohn- 

 liche Eisfreiheit des ostspitsbergischen Meeres in Wechselbeziehung 

 stand. Nordlich von Konig-Karls-Land betrug die Oberflachen- 

 temperatur des Meeres -\- 5°C, nordlich von Nord-Ost-Land tiber 



