G. Dynamic Topographies 



In order to draw dynamic height charts of the Ross Sea (Figs. 27, 28, 

 29, and 30) and include data from all the stations, the 200-decibar level 

 was used. This is not a level of no motion, but it does permit an esti- 

 mation of circulation in the area. Comparison between the 150-decibar 

 surface (Fig. 30) and the surface of Shelf Water (Fig. 19) shows some 

 correlation of the streamlines with the surface of the Shelf Water mass. 

 The streamlines determined on DEEP FREEZE 61 for the eastern Ross Sea at 

 theO- and 50-decibar surfaces show good correlation with DEEP FREEZE 63 

 and 64 determinations. Maximum currents appear at the surface decreasing 

 with depth. Streamlines at all levels generally agreed as to direction 

 of flow. 



The main movement within the Ross Sea appears to be little more than 

 a drift, although a current does parallel the Ross Ice Shelf. All other 

 movement appears to be surface movement caused by wind stress. Movement 

 of the Antarctic Circumpolar and Shelf Water masses may be caused by rapid 

 seasonal changes with the formation of a dense water mass in the winter 

 and the intrusion of the Antarctic Circumpolar Water in the summer. 



37 



