70 Hydkography of the Stream 



(thus, tidal variations and magnetic storm signals are averaged out). 

 Perhaps the most striking feature of these fluctuations is the extreme 

 rapidity with which major changes in transport can occur. 



THE NORTH ATLANTIC CURRENT 



There are not a great many observations of the North Atlantic Current 

 (Defant, 1939; Neumann, 1940; Soule, 1950). The Atlantis made a section 

 from 37° N. to 52° N. along 30° W. longitude in 1931 (Iselin, 1936), here 

 sho^\^l as fig. 42, and the International Gulf Stream Expedition of 1938 

 (the Altair and the Armauer Hansen) made some sections in the area. What 

 data there are suggest that the North Atlantic Current is not a single, 

 narrow current like the Gulf Stream off the United States coast, but is 

 made up of several distinct broad currents. Just how permanent these 

 currents are has not been determined. Iselin (1936) and Sverdrup, Johnson, 

 and Fleming (1942) have supposed that the Gulf Stream System sphts into 

 a number of branches just east of the tail of the Grand Banks. Fughster 

 (19516) has proposed that there is no real branching at aU. He has drawn 

 a schematic set of streamUnes which fit the data well, and caUs his schema 

 the Multiple Current Hypothesis. He suggests that an instantaneous chart 

 would show not a continuous stream, but a number of disconnected fila- 

 ments of current. This pattern changes from time to time. The possibility 

 that the current system of the North Atlantic Current is irregular and 

 varying and actually discontinuous is very disconcerting. It is even more 

 disturbing to find that Fughster is able to draw these alternative inter- 

 pretations even about the water as far west as 65° W. longitude, where we 

 have always thought of the Gulf Stream as unambiguous^ identifiable. 

 Figs. 43-45 represent three interpretations of the nature of the north- 

 eastern parts of the Gulf Stream, according to Fughster (1955, charts 

 3a-3c, all based on the same data). These illustrate clearly the difiiculties 

 of adequate description of the Gulf Stream System. In my opinion, the 

 interpretation in fig. 45 is a bit forced, from an attempt to spread iso- 

 therms apart wherever possible. On the other hand, fig. 43 is forced in 

 the opposite way. Fig. 44 corresponds most nearly to Fuglister's picture of 

 multiple streams and seems intuitively, to me, to be the most natural 

 interpretation. 



