Balmer profiles in the geocorona and interstellar space I. Asymmetries due to fine structure

In principle, we can analyze Doppler profiles of Balmer-alpha and -beta to extract orbital information about escaping and satellite geocoronal particles. In practice, our interpretations are hampered because we do not fully understand what the profile would be in the absence of any peculiarly geocoronal characteristics (e.g., an asymmetry due to the absence of any downward directed particles exceeding the velocity of escape; broadening characteristics of distant satellite particles). Here we look at profiles for H atoms that emit radiation from a complete Maxwellian distribution, but which exhibit some asymmetry due to the fine structure of H-alpha. This asymmetry is a predictive function of the excitation mechanism.