V -'.---s.'- j> ■ *i-^»SfeS"il "~ i.---r-'":,'"')>-<^-.-*'->*i'* -. ^^ti^V^'-i' ;&^"i^iisfe5^ 



3 _ 



MOST FREQUENT HEIGHT 1600 FT 



Figure 3-10. — Cloud heights are lower in the Arctic. 



the pack ice than over the coastal areas. In winter the number 

 of cloudy days will generally run between 6 and 12 a month, the 

 greater number occurring in the same areas as the least number 

 of clear days. 



The conditions described apply only to the arctic basin and the 

 adjacent coastal areas. In the interior of the continents within 

 the arctic zone cloudiness is appreciably different. In particular 

 the summer cloudiness is much less, with few cloudy or overcast 

 days, but with a large proportion of partly cloudy days. The 

 clouds are mostly of a cumuliform nature, as contrasted to the 

 stratus clouds of the arctic basin. In winter the cloudiness of 

 these interior sections is largely governed by their location with 

 respect to the moving cyclonic disturbances. Those localities near 

 the paths of the disturbances will have a high percentage of cloudi- 

 ness with a large number of cloudy days. Other localities far 

 removed from the paths of storms will have less cloudiness, with 

 a larger number of clear or partly cloudy days. 



Cloud heights are lower in the Arctic than in the temperate 

 latitudes. The most frequent type of cloud, the stratus clouds, 

 will be found anywhere between zero and 5,000 feet. The obser- 

 vations on the Maud indicated that the most frequent height is 

 below 1,600 feet. However, the measurement of the ceilings were 



119 



