A post‐Pioneer Venus reassessment of the Martian dayside ionosphere as observed by radio occultation methods

M.H.G. Zhang, Janet Luhmann, A.J. Kliore, Jhoon Kim

Research output: Contribution to journalArticle


The dayside altitude profiles of the electron density obtained with the radio occultation experiments on Mariners 4, 6, 7, and 9 and the Viking 1 and 2 spacecraft are collectively reanalyzed to determine the global characteristics of the dayside ionosphere of Mars. These analyses concentrate on the comparison of the properties of both the electron density peaks and the topside profiles with the behavior expected for a Chapman layer and that observed at Venus with the Pioneer Venus orbiter radio occultation experiment. As at Venus, the peak densities at Mars behave much like Chapman layer peaks with only slight departure from a (cosθ) ½ dependence, where θ is the solar zenith angle. In contrast, the peak heights depart from ideal Chapman layer behavior at Venus but not at Mars because the dayside neutral atmosphere at Venus depends on solar zenith angle. The global dust storm during the Mariner 9 main …
Original languageEnglish
Article number10.1029/JB095iB09p14829
Pages (from-to)14829-14839
JournalJournal of Geophysical Research B: Solid Earth
Publication statusPublished - 1990 Aug 30


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