PLATEAU WINDS. 



145 



were from the same direction as the less strong winds his observations have been divided 



into two classes: the first containing winds up to strength 4 on the Beaufort scale and the 



second those of greater strength. The result reduced to percentage frequency is shown in the 

 following table. 



Table 77. 



For the lower wind strength the most frequent direction was W.S.W., while for the higher 

 winds the greatest frequency was from the S. and S.S.W. It will be noticed that with the 

 higher winds there is a second maximum at the W.S.W. It should be pointed out, however, 

 that all the winds in this class occurred when Captain Scott was very near to the head of the 

 Ferrar Glacier valley and therefore were probably more westerly than they would have been 

 on the open plateau, on account of the tendency of winds to blow down the glacier valleys. 

 These few observations point to the blizzards on the Western Plateau being slightly west 

 of south, while the normal fair weather winds are more nearly from the W.S.W. Thus, the 

 conditions associated with blizzards add a strong southerly component to the prevailing W.S.W. 

 winds. 



Soutli Polar Plateau.— We have already shown that the prevailing winds on the South 

 Polar Plateau are from the S.S.E., S. and S.S.W., the^e three directions taking 63 per cent, 

 of the wind observations and 75 per cent, of the total air motion. While Scott was on the 

 plateau he recorded wind of force 5 and over on 23 occasions, 22 of which were from these 

 same directions, the remaining observations being from the S.W. Thus, Scott's observations 

 show practically no high winds from any dii-ection except S.S.E., S. and S.S.W. During 

 the first five days that Amundsen was on the plateau, he experienced high winds from the 

 S.E., E.S.E. and E.N.E., during the remaining 40 days like Scott he experienced high winds 

 only from S.S.E., S. and S.S.W. Grouping all Scott's and Amundsen's observations together, 

 we get the following percentage of high and low winds under each direction. 



Table 78. 



Percentage frequency of High and Loiv Wituls on the South Polar Plateau (November 22 



to February 4; S. = parallel to 160" E.). 



* Apiundaen 8 metres per second and over. 



I? 



