Temporal variability of waves at the proton cyclotron frequency upstream from Mars: Implications for Mars distant hydrogen exosphere

• Published in: Geophysical Research Letters
• Main Authors: Bertucci, Cesar, Romanelli, Norberto Julio, Chaufray, J. Y., Gomez, Daniel Osvaldo, Mazelle, C., Delva, M., Modolo, R., González Galindo, F., Brain, D. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union
• Subjects: MARS; EXOSPHERE; PICK UP; https://purl.org/becyt/ford/1.3; https://purl.org/becyt/ford/1; Argentina; South Pole; Gomez; South pole
• Online Access: http://hdl.handle.net/11336/17062

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. Fil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Romanelli, Norberto Julio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Chaufray, J. Y. LATMOS; Francia Fil: Gomez, Daniel Osvaldo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Mazelle, C. IRAP; Francia ...