REVIEW OF DYNAMICS OF DISTRIBUTIONAL CONTROL 431 



cyclone, but places its centre some 5° farther north than Meyer originally placed it. Sverdrup (1942, 

 chart 4), also evidently following Meyer, shows eastern and western cyclones at the surface. Sverdrup, 

 Johnson and Fleming (1946, chart vii) and the Marine Atlas published by the U.S.S.R. Ministry of 

 Defence (1953) again show two rotary surface movements, an eastern and a western, both of them 

 centred about much the same positions as Meyer's. Without figuring it Colman (1950) states there 

 is a clockwise gyral in the Weddell Sea. Leip (1954, p. 21) shows a western vortex only, revolving 

 about 30° W with its centre a little to the north of 70° S, Muromtsev (1956, p. 58) a western 

 cyclone in approximately the same position and an eastern one, again involving the return of 

 the Weddell to the East Wind stream, between 30° and 60° E. Deitrich (1957, Tafel 5), Taljaard 

 (1957, chart i) and Yevgenov (1957, Fig. 18) show the two Meyer cyclonic systems, but Taljaard 

 questions the reality of the eastern one. The 1957 American oceanographic atlas shows only the 

 eastern system, omitting Meyer's rotary circulation in the heart of the Weddell Sea. Bruns (1958, 

 Fig. 105) also omits Meyer's western vortex, but shows the Weddell stream curling back to the East 

 Wind drift between 40° and 80° E. The Times Atlas of the World (Bartholomew, 1958) shows the 

 surface stream moving coastwise round the Weddell Sea, up the east coast of Graham Land and away 

 to the north and east. It omits both eastern and western vortices and in this (see below) probably 

 provides the most reliable interpretation to date of the available hydrological evidence. 



Ruud (1932) ascribes the abundance and continued existence of the population in the western and 

 eastern parts of the Atlantic sector to Meyer's cyclonic systems, suggesting there may be similar 

 systems operating in other parts of Antarctica, notably, for instance, on the outskirts of the Ross Sea. 

 He suggests that although the bulk of the larvae produced in the western part of the Weddell Sea, 

 probably he supposes in the inaccessible heart of Meyer's western vortex, get carried to the north 

 and east in the surface stream, some get involved in the cyclonic movements and so as adults eventually 

 return to spawn in the higher latitudes from which they sprang. In other words he postulates a 

 mechanism of distributional control involving rotary movements in the surface alone. It will be 

 recalled, however (p. 97), that Ruud's nets did not go deep enough for him to see, as Eraser did, the 

 part the warm deep current, as an early larval carrier, may also play in the return of the krill to the 

 south. 



Although basically correct, in so far as there is on the Atlantic side an undoubted clockwise move- 

 ment of developing larvae in the East Wind- Weddell surface stream, Ruud's circulation, in so far as 

 its terminal phase (the return of his adults in the surface) is concerned, is based as Eraser 

 observes on very scanty hydrological evidence. Wiist (1933), for instance, suggests that Meyer's two 

 cyclonic movements do not in fact exist, nor do the comprehensive hydrological data of the Discovery 

 Investigations (Deacon, 1937, p. 28) provide any definite indication of a southward movement at the 

 surface linking the east-going Weddell with the west-going East Wind stream. Deacon writes, 

 'The movement towards the west, the northward current along the east coast of Graham Land, and 

 the current flowing out of the Weddell Sea towards the east, form three parts of a cyclonic movement 

 which extends across the entire width of the Atlantic Ocean. The surface temperature distribution 

 indicates that the cyclonic movement may be completed by a southward movement between 20° and 

 40° E ; there is, however, very little evidence of such a current at the surface '.^ Model (1958), using all 

 available hydrological data to date, but ignoring data obtained between the surface and 75 m. shows 

 what appears to be evidence of a shallow southward subsurface movement in i8°-25° E at a depth of 

 75-100 m., and, like Deacon, a strong south-westerly movement in the warm layer between 200 and 

 400 m. 



1 Schott (1924, Fig. 34), Brown (1927, Fig. 10), Debenham (1923, end map A) and Aagaard (1930, 11, end chart) also show 

 the coastwise current moving clockwise round the Weddell Sea, but nowhere any southward return at the surface. 



