A search for molecular hydrogen fluorescence near 100 km
Abstract
The fluorescence of H2 in the Lyman band system, excited by solar extreme ultraviolet radiation, provides a means for the optical detection of H2 in the upper atmosphere. In particular, the Ly line of hydrogen is nearly degenerate with the (6,0) P1 transition, and absorption in this line produces fluorescence in the v=6 progression, principally at 1265, 1366, 1462 and 1608 Å. Absorption by 02 rapidly attenuates the Ly from an overhead sun below 100 km and also significantly attenuates the fluorescent radiation. Farultraviolet dayglow spectra from 1130 to 1510 Å obtained from an Aerobee rocket experiment on 11 December 1972 give an upper limit for any H2 emission which is a factor of 5 higher than expected according to recent hydrogen models.
- Publication:
-
Journal of the Atmospheric Sciences
- Pub Date:
- November 1975
- DOI:
- 10.1175/1520-0469(1975)032<2209:ASFMHF>2.0.CO;2
- Bibcode:
- 1975JAtS...32.2209F
- Keywords:
-
- Far Ultraviolet Radiation;
- Fluorescence;
- Hydrogen;
- Molecular Spectra;
- Radiation Effects;
- Solar Radiation;
- Atmospheric Attenuation;
- Atmospheric Radiation;
- Dayglow;
- H Beta Line;
- Lyman Spectra;
- Mesosphere;
- Molecular Excitation;
- Upper Atmosphere