Accession Number:

AD0745305

Title:

Annual and Sub-Annual Effects of EUV (Extreme Ultraviolet) Heating. Volume I. Harmonic Analysis,

Descriptive Note:

Corporate Author:

AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s):

• Ching,Barbara K.
• Chiu,Yam T.

Report Date:

1972-04-15

Pagination or Media Count:

39.0

Abstract:

The authors compute the rate of solar extreme ultraviolet radiation EUV heating in the upper atmosphere by photo-dissociation and photo-ionization, taking care to include properly the effects of oblique incidence of solar flux, sphericity of the atmosphere and ellipticity of the earths orbit. The time and latitudinal variations of the computed heat function are revealed by numerical Fourier analysis of the heat function into harmonics of the yearly cycle. It is shown that EUV absorption contains a latitude independent semi-annual component of heating with the proper phase to account for the semi-annual density variations. Further, the annual component of the heat function predicts the existence of summer polar density increases in the northern and southern hemispheres. Author

Descriptors:

• (*UPPER ATMOSPHERE
• HEATING)
• DENSITY
• ULTRAVIOLET RADIATION
• SOLAR RADIATION
• PHOTOCHEMICAL REACTIONS
• GAS IONIZATION
• DISSOCIATION
• FOURIER ANALYSIS
• ABSORPTION
• HARMONIC ANALYSIS

Subject Categories:

• Atmospheric Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE