The frequency of gales in Alaska is similar to that of eastern 

 Siberia. In the interior the season of greatest frequency is sum- 

 mer. Along the coast the season of greatest frequency is winter. 

 Coastal stations have a greater annual frequency than inland sta- 

 tions. Point Barrow on the north coast has an average of 18.7 

 gales a year, while Fairbanks in the interior has an average of 

 only 0.9. Wrangel Island has an annual average of 50.4 gales. 

 From May through August there is an average of two each month. 

 The season of low average at Wrangel Island is associated with 

 the summer, at which time the Polar Anticyclone is weakest and 

 the Aleutian Low is dissipated. During the colder months from 

 September to April the average monthly frequency is between five 

 and six. At this season the Polar Anticyclone is present and the 

 Aleutian Low is well developed. 



OVER NORTHERN CANADA 



Little is known of the upper-wind regime of northern Canada. 

 The elevation of the many islands of the Canadian archipelago is 

 not great. The area is covered with ice and snow a great portion 

 of the year. An extension of the Polar Anticyclone extends down 

 over this region. A steady flow of air out of this high pressure 

 area continues throughout most of the year, being greatest in win- 

 ter when the anticyclone is most highly developed. As a result, 

 winds across the Hudson Bay region are northwesterly in winter. 

 The depth of this northwesterly current is reflected in the winds 

 aloft at Port Harrison. Northwesterly winds are most frequent 

 up to the limit of observational data at 13,000 feet. Progressing 

 from winter to summer the Polar Anticyclone and its Canadian 

 extension gradually weaken, so that the northwesterly surface 

 winds do not penetrate as far south as Port Harrison. Aloft, how- 

 ever, there is still a prevalence of northwesterly wind at 6,000 to 

 13,000 feet, although the velocities are not as great. There are no 

 data as to the number of gales in this region. But in the colder 

 months of the year, during the presence of high pressure there 

 would be few gales. In the warmer months the weakened anti- 

 cyclone would allow cyclones to invade this region, with attendant 

 gales. 



The ice-covered region of Greenland, because of its high eleva- 

 tion and great size, exerts a considerable influence on the wind 

 flow in its vicinity. The wind circulation in close proximity re- 

 sembles that of an anticyclone. At Etah, in northwest Greenland, 

 during the winter, the prevailing winds, from the surface to 3,000 



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