tions much higher readings are found and maxima near 70° F. 

 are quite common. Still greater maxima are recorded at inland 

 stations, and temperatures above 90° F. are the rule at stations 

 near the arctic circle which are a considerable distance from the 

 sea. 



There are two features worthy of note which characterize the 

 summer temperatures in the polar sea: (1) The temperature is 

 near freezing everywhere with no variation with latitude and 

 (2) again independent of latitude, the first day with a maximum 

 temperature and the first day with a mean temperature of 32° F. 

 or higher is nearly the same in all sections except those under the 

 influence of warm winds from the south. 



PRECIPITATION 



There are two significant factors which make it extremely dif- 

 ficult to obtain satisfactory measurements of precipitation in the 

 Arctic: (1) The fine ice needles of winter precipitation are very 

 easily blown across the rain gage opening and (2) during snow 

 storms it is diflScult to determine whether the snow is falling or 

 is being blown up from the surface. Another obstacle is de- 

 termining the number of days with a measurable amount of 

 precipitation. On extremely cold days the snow is very fine, and 

 there are many days when precipitation is so slight that it can- 

 not be measured but is present nevertheless. A striking example 

 is found in records of the Norwegian north polar expedition. At 

 Goose Fiord, Ellesmere Island, eleven days in April were recorded 

 on which precipitation occurred, but the total for the month 

 showed only 0.2 mm. or slightly less than 0.01 inch. On the 

 North American continent the number of days with precipitation 

 is determined from the days on which 0.01 inch or more is 

 measured. Other stations use days with 0.1 mm. or more, while 

 still other stations have tabulated all the days when precipitation 

 occurred. 



In the arctic and subarctic regions the inadequacy of the records 

 permit only broad and general statements regarding yearly aver- 

 ages and seasonal distribution. The time of year of maximum 

 precipitation varies with the prominence of marine or continental 

 influence. It is a well known fact that snowfall is extremely 

 light and stations in continental areas have maximum precipita- 

 tion in late summer, indicating that a large percent of the yearly 

 total falls as rain. 



128 



