Geophysical Institute-Alaska University— Wilson 191 



(2) Theoretical Studies 



Theoretical studies on the state of the atmosphere in the 

 arctic were started in the spring of 1948. They are still in 

 progress and are naturally based upon existing theories of the 

 upper atmosphere and such new postulates as have become 

 necessary. Data obtained from the programs in progress at the 

 Institute have been used to test the hypotheses. Some of the 

 problems attacked are the magnitude of the lunar diurnal wave 

 in the ionosphere 300 km. above the surface of the earth, the 

 correlations (almost inverse) between ground barometric pres- 

 sure and the F-layer semithickness and a delineation of wind 

 systems in the ionospheric regions. (See references at end of the 

 discussion on ionospheric measurements.) 



(3) The determination of ozone in the atmosphere 



A series of measurements of the daily concentration of ozone 

 in the atmosphere near the surface was started in January 1950 

 and is still in progress. Ozone is absorbed in a solution of so- 

 dium arsenite following a method described at length by Dau- 

 villier (Polar Year, Scoresby Sund, 1932-33). Comparative ex- 

 periments with sodium thiosulfate indicate that the arsenite 

 method gives more uniform results due to the greater stability 

 of these solutions at the low concentrations involved. These 

 daily determinations show certain extremely high values which 

 seem to be significant even though a few may represent experi- 

 mental eccentricities. However, certain exceptional values such 

 as those of February 8/9 did correspond to an isothermal sound- 

 ing of the atmosphere, and are thus comparable to Dauvillier's 

 value and probably have the same explanation. The amounts 

 of ozone present in winter are nearly 10 times those observed 

 in summer. The average values are many times as great as 

 those in the temperate zones. A study of the monthly averages 

 shows a maximum in March to April and a secondary maximum 

 in the summer. A similar progression of values for total ozone 

 concentration in the Northern latitudes has been noted by 

 several observers. 



