Temporal variability of waves at the proton cyclotron frequency upstream from Mars: Implications for Mars distant hydrogen exosphere. Issue 15 (1st August 2013)

• Record Type: Journal Article
• Authors: Bertucci, C.; Romanelli, N.; Chaufray, J. Y.; Gomez, D.; Mazelle, C.; Delva, M.; Modolo, R.; González‐Galindo, F.; Brain, D. A.
• Is Part Of: Geophysical research letters. Volume 40:Issue 15(2013:Aug.)
• Page Start: 3809
• Page End: 3813
• Publication Date: 2013-08-01
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/grl.50709
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>[1] We report on the temporal variability of the occurrence of waves at the local proton cyclotron frequency upstream from the Martian bow shock from Mars Global Surveyor observations during the first aerobraking and science phasing orbit periods. Observations at high southern latitudes during minimum‐to‐mean solar activity show that the wave occurrence rate is significantly higher around perihelion/southern summer solstice than around the spring and autumn equinoxes. A similar trend is observed in the hydrogen (H) exospheric density profiles over the Martian dayside and South Pole obtained from a model including UV thermospheric heating effects. In spite of the complexity in the ion pickup and plasma wave generation and evolution processes, these results support the idea that variations in the occurrence of waves could be used to study the temporal evolution of the distant Martian H corona and its coupling with the thermosphere at altitudes currently inaccessible to direct measurements.</p> </abstract>