MAVEN Observations of the Effects of Crustal Magnetic Fields on Electron Density and Temperature in the Martian Dayside Ionosphere. Issue 21 (4th November 2017)

• Record Type: Journal Article
• Authors: Flynn, Casey L.; Vogt, Marissa F.; Withers, Paul; Andersson, Laila; England, Scott; Liu, Guiping
• Is Part Of: Geophysical research letters. Volume 44:Issue 21(2017)
• Page Start: 10, 812
• Page End: 10, 821
• Publication Date: 2017-11-04
• Subjects: Mars -- ionosphere; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL075367
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Mars lacks a global magnetic field but possesses concentrated regions of crustal magnetic field that influence the planet's interaction with the solar wind and the structure of the Martian ionosphere. In this study we survey 17 months of MAVEN Langmuir Probe and Waves dayside electron density and temperature measurements to study how these quantities are affected in regions with strong crustal magnetic fields. Above 200 km altitude, we find that regions of strong crustal magnetic fields feature cooler electron temperatures and enhanced electron densities compared to regions with little or no crustal magnetic field. Neutral densities and temperatures are not significantly affected. Closed field lines on which electrons can be trapped are more prevalent in strong crustal field regions than elsewhere. Trapped on closed field lines, electrons are protected against loss processes involving the solar wind. This would lead to longer plasma lifetimes, higher densities, and lower temperatures. Key Points: MAVEN Langmuir Probe and Waves (LPW) measurements are used to study the effects of crustal magnetic fields on electron densities and temperatures Regions of strong crustal magnetic field feature higher electron densities and lower electron temperatures than noncrustal field regions Neutral densities and temperatures are not significantly affected