Accession Number : AD0282050

Title :   EFFECTS OF COSMIC RADIATION ON THE EXTREMELY LOW FREQUENCY PROPERTIES OF THE MESOSPHERE,

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : Goldberg,P. A.

Report Date : JUL 1962

Pagination or Media Count : 27

Abstract : At extremely low frequencies (1 to 3000 cps), relatively slight amounts of ionization can produce notable effects on electromagnetic phenomena in the terrestrial system. Representative atmospheric conditions are examined to find minimum conditions that can produce such strong ELF effects at geophysically quiet periods. Based on analyses of ion production parameters it is found that even for quiet nights, when only cosmic radiation is important for producing ionization in the mesosphere, large refractivities can be produced in this portion of the atmosphere below the ionosphere. For even a minimum electron detachment condition the refractive index of the mesophere has the large magnitude of 4 at an altitude 75 km. For a more inclusive ion production condition with a maximum detachment factor that collates with VLF observations, strong refractivity effects occur at quite low altitudes; namel 35 km at 1 cps, 50 km at 10 cps, 55 km at 100 cps, and 65 km at 1000 cps. At VLF frequencies (10 KC and above) effective altitudes for the night time lower ionosphere take on values normally assumed. During daytime and active solar periods it is indicated that strong refractivity effects will occur at altitudes below 30 km. (Author)

Descriptors :   *EXTREMELY LOW FREQUENCY, *IONSPHERE, *COSMIC RAYS, REFRACTION, RADIATION EFFECTS, IONIZATION, ELECTROMAGNETIC EFFECTS, ELECTRON DIFFRACTION, ATMOSPHERICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE