Journal article
Response of the Martian ionosphere to solar activity including SEPs and ICMEs in a two-week period starting on 25 February 2015
Planetary and space science, Vol.145, pp.28-37
10/01/2017
DOI: 10.1016/j.pss.2017.07.010
Abstract
In a two-week period between February and March of 2015, a series of interplanetary coronal mass ejections (ICMEs) and solar energetic particle (SEP) events encountered Mars. The interactions were observed by several spacecraft, including Mars Express (MEX), Mars Atmosphere and Volatile Evolution Mission (MAVEN), and Mars Odyssey (MO). The ICME disturbances were characterized by an increase in ion speed, plasma temperature, magnetic field magnitude, and energetic electron flux. Furthermore, increased solar wind density and speeds, as well as unusually high local electron densities and high flow velocities were detected on the nightside at high altitudes during the March 8 event. These effects are thought to be due to the transport of ionospheric plasma away from Mars. In the deep nightside, the peak ionospheric electron density at the periapsis of MEX shows a substantial increase, reaching number densities about 2.7 × 104 cm−3 during the second ICME in the deep nightside. This corresponds to an increase in the MO High-Energy Neutron Detector flux suggesting an increase in the ionization of the neutral atmosphere due to the high intensity of charged particles. Measurements of the SEP fluxs show a substantial enhancement before the shock of a fourth ICME causing impact ionization and absorption of the surface echo intensity which drops to the noise levels, below 10−15 V2m−2 Hz−1 from values of about 2 × 10−14 V2m−2 Hz−1. Moreover, the peak ionospheric density exhibits a discrete enhancement over a period of about 30 h around the same location, which may be due to impact ionization. Ion escape rates at this time are estimated to be in the order of 1025 to 1026 s−1.
•An investigation of the ionosphere and solar wind environment of Mars during a high solar activity period is provided.•Solar energetic particles, high ionospheric densities and absorption of the surface intensity are observed on the nightside.•ICMEs increase the ion escape rates.•A top-hat feature in the peak electron density is observed.
Details
- Title: Subtitle
- Response of the Martian ionosphere to solar activity including SEPs and ICMEs in a two-week period starting on 25 February 2015
- Creators
- F Duru - University of IowaD.A Gurnett - University of IowaD.D Morgan - University of IowaJ Halekas - University of IowaR.A Frahm - Southwest Research InstituteR Lundin - Swedish Institute of Space PhysicsW Dejong - Coe CollegeC Ertl - Coe CollegeA Venable - Coe CollegeC Wilkinson - Coe CollegeM Fraenz - Max Planck SocietyF Nemec - Charles UniversityJ.E.P Connerney - Goddard Space Flight CenterJ.R Espley - Goddard Space Flight CenterD Larson - University of California, BerkeleyJ.D Winningham - Southwest Research InstituteJ Plaut - Jet Propulsion LaboratoryP.R Mahaffy - Goddard Space Flight Center
- Resource Type
- Journal article
- Publication Details
- Planetary and space science, Vol.145, pp.28-37
- DOI
- 10.1016/j.pss.2017.07.010
- ISSN
- 0032-0633
- eISSN
- 1873-5088
- Publisher
- Elsevier Ltd
- Grant note
- DOI: 10.13039/100006196, name: Jet Propulsion Laboratory at the University of Iowa, award: 156064; DOI: 10.13039/100011766, name: Southwest Research Institute, award: NASW-00003; DOI: 10.13039/501100001859, name: Swedish National Space Board
- Language
- English
- Date published
- 10/01/2017
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199668802771
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