Observation of bow shock protons at the lunar orbit
Benson, John Louis
Freeman, John W.
Master of Science
Protons with energies ranging from about 5 eV to 35 eV are observed by the Suprathermal Ion Detector Experiment on both the dusk and dawn sides of the. magnetosphere. On each lunation these particles appear as a rather continuous phenomenon for 3 to 5 days after crossing from the dawn-side magnetosheath into the solar wind and for about 2 days prior to entering the dusk-side magnetosheath. Transverse proton flows of this type have been observed by Asbridge et al., , Scarf et al.,  and are believed to be deviated solar wind particles that are accelerated at the earth's bow shock and emitted outwardly along interplanetary field lines at greater than solar wind energies. Data from the SIDE and from the Explorer 35 lunar orbiting magnetometer have been analyzed and these data indicate that the transverse ion flows observed by the SIDE in the pre and post bow shock crossing regions of the lunar orbit are due to these deviated solar wind particles. A computer model based on EXB drift trajectories for particles leaving the shock has been developed and synthetic particle data produced by this model are in good agreement with the observed data.