Geophysical Institute-Alaska University— Wilson 187 



statistical devices. Several investigations based on this set of 

 data have been reported: 



1. CRPL D-Series, F-Series and E-Series 



2. Carnegie Institution of Washington, Ionospheric and Auroral 



Studies at College, Alaska, 1941-46. 



3. Tidal Effects in the F-layer, M. W. Jones and J. G. Jones, 



Physical Review, j6, 581, (1949). 



4. Thickness of Winter F-layer in Polar Regions — M. W. Jones, 



Trans. Am. Geophys. Union, 5/, 187-190 (1950). 



5. State of the Upper Atmosphere — S. L. Seaton, Jour. Met. 4, 



*93 0947)- 



6. Magnetonic Multiple Refraction at High Latitudes, S. L. 



Seaton, Proc. Inst. Radio Eng., 36, 450-454 (1948). 



7. Generalized Magneto-Ionic Theory— N. C. Gerson and S. L. 



Seaton, J. Frank. Inst., 246, 483-494 (1948). 



8. A Correlation between Ionospheric Phenomena and Surface 



Pressure — M. W. Jones and J. G. Jones. 



9. State of the Earth's Atmosphere in the Arctic — Research Re- 



ports Nos. 1-8, Contract W2 8-099^-445 Airforce Cambridge 

 Research Laboratories, Cambridge, Mass. 



Signal Intensity Measurements 



Continuous measurements of the strengths of radio signals 

 traversing various long and short paths ending at College are 

 being recorded. These data supplement the ionospheric meas- 

 urement program. The records of variations of signal strength 

 with time over the longer distances give information which per- 

 mits verification and extension of wave propagation theory for 

 use in establishing and maintaining satisfactory long distance 

 communications in all parts of the world. Recordings over short 

 distances are applicable to studies of absorption of wave energy 

 in the ionosphere locally and to extension of knowledge of the 

 upper atmosphere generally. The results from this phase of the 

 work are transmitted to the proper contracting agency and are 

 part of the internal operations of these agencies. 



The sky-wave radio propagation in the auroral zone is sub- 

 ject to peculiar variations. Part of Alaska is in the maximum 



