h*fc»a $ It) , __£l* 



^ (stability due to stratification) 



VI. SUMMARY AND CONCLUSIONS 



An analysis for the spectral periods of internal waves was made from 

 temperature readings, comprising nearly 1,200 bathythermograms taken at 

 half-hourly intervals during Operation STANDSTILL. The analysis shows no 

 significant power associated with periods from 1 to 20 hours, but a con- 

 centration of the power in the band of periods between 20 and 26 hours. If 

 there is no aliasing from periods of less than 1 hour, it may be concluded 

 that the analysis of the temperature data fails to show that internal waves 

 of periods of less than 20 hours carry any appreciable amount of power at the 

 location of the operation. 



Two possible causes are suggested for the predominance of spectral periods 

 between 20 and 26 hours: formation of eddies on the southern edge of the 

 Gulf Stream due to instability gives periods of 21.7 hours, but the diameter 

 of the eddies is too small to account for the observed isothermal changes; 

 internal motion due to forced inertial oscillation is suggested, with a period 

 somewhat more than 21.7 hours. The latter oscillation apparently is in re- 

 sonance with the diurnal tidal components, and as a result the spectral power 

 is concentrated in the observed periods. 



-"See Fjeldstad, J. E., Interne Wellen, Geofysiske Publikasjoner, Vol. X, 

 No. 6, Oslo, 1933. 



