114 



H. IMOHN. IMETEOROLOGY. [2nd. ARC. EXP. FRAM 



morning hours, and a maximum some houi's after noon. The range 

 has a maximum in the spring months, April and May. 



With an overcast sky, we find the ordinary daily period in every 

 month, even in the dark season. The range comes out rather high 

 in January, but has its maximum in April, and is rather low in the 

 summer months. 



The daily period of the temperature of the air in the arctic and 

 antarctic regions deserves a fuller investigation by means of all the 

 available observations. It is particularly the inverted period with a clear 

 sky and the ordinary period with an overcast sky in the dark season 

 that promise, when their causes can be found, to throw a new light 

 upon the work of radiation from and to the earth in the lower atmos- 

 phere. It is with this end in view that I have discussed the obser- 

 vations from the Fram's drift in 1893 to 1896 1. 



The Tables on pp. 63—107 give the minimum and the maximum 

 temperature for each day, and their difference, or the aperiodic range. 

 The last horizontal row shows the monthly means of these three 

 columns. Putting these means together, we have the following Tables. 

 The brackets indicate the incomplete months. 



Mean monthly Minima. 



Mean monthly Maxima. 



The Norwegian North Polar Expedition, 1893-1896. Scientific Results, edited by 

 Fridtjof Nansen. Vol. VI, pp. 473-481, and 603-6O7. 



