Characterization of Low‐Altitude Nightside Martian Magnetic Topology Using Electron Pitch Angle Distributions

Weber, Tristan; Brain, David; Mitchell, David; Xu, Shaosui; Connerney, J. E. P.; Halekas, J. S.

doi:10.1002/2017ja024491

Cited by 65 publications

(124 citation statements)

References 34 publications

Supporting

Mentioning

121

Contrasting

Order By: Relevance

“…Mars is unique among terrestrial planets in its possession of multiple magnetic anomalies of small spatial scale in the crust (e.g., Acuna et al, , ; Connerney et al, ), which leads to a complex pattern of ambient magnetic field configuration in the vicinity of the planet (e.g., Harada et al, ; Lillis et al, ; Mitchell et al, ; Weber et al, ; Xu, Mitchell, Liemohn, et al, , Xu, Mitchell, Luhmann, et al, ). The dayside and nightside mappings of both the magnetic field strength and elevation angle are displayed in Figure , extracted from the MAVEN Magnetometer level 2 data at 350–450 km (Connerney et al, ).…”

Section: Impacts Of the Magnetic Field Configurationmentioning

confidence: 99%

The Morphology of the Topside Martian Ionosphere: Implications on Bulk Ion Flow

Cui

et al. 2019

JGR Planets

Self Cite

View full text Add to dashboard Cite

Prior to the Mars Atmosphere and Volatile Evolution mission, the only information on the composition of the Martian ionosphere came from the Viking Retarding Potential Analyzer data, revealing the presence of substantial ion outflow on the dayside of Mars. Extensive measurements made by the Mars Atmosphere and Volatile Evolution Neutral Gas and Ion Mass Spectrometer allow us to examine the morphology of the Martian ionosphere not only in unprecedented detail but also on both the dayside and the nightside of the planet. Above 300 km, various ionospheric species present a roughly constant density scale height around 100 km on the dayside and 180 km on the nightside. An evaluation of the ion force balance, appropriate for regions with near‐horizontal magnetic field lines, suggests the presence of supersonic ion outflow predominantly driven by the ambient magnetic pressure, with characteristic dayside and nightside flow velocities of 4 and 20 km/s, respectively, both referred to an altitude of 500 km. The corresponding total ion outflow rates are estimated to be 5 × 1025 s−1 on the dayside and 1 × 1025 s−1 on the nightside. The data also indicate a prominent variation with magnetic field orientation in that the ion distribution over regions with near‐vertical field lines tends to be more extended on the dayside but more concentrated on the nightside, as compared to regions with near‐horizontal field lines. These observations should have important implications on the pattern of ion dynamics in the vicinity of Mars.

show abstract

Section: Impacts Of the Magnetic Field Configurationmentioning

confidence: 99%

The Morphology of the Topside Martian Ionosphere: Implications on Bulk Ion Flow

Cui

et al. 2019

JGR Planets

Self Cite

View full text Add to dashboard Cite

show abstract

“…Furthermore, these planetary fields are able to undergo magnetic reconnection with the impinging IMF (Brain, 2006;Halekas et al, 2009;Harada et al, 2018). In particular, the structure of the Martian magnetotail is populated with a variety of field topologies (Brain et al, 2007;Weber et al, 2017;Xu, Mitchell, Liemohn, et al, 2017;Xu, Mitchell, Luhmann, et al, 2017) that DIBRACCIO ET AL. In particular, the structure of the Martian magnetotail is populated with a variety of field topologies (Brain et al, 2007;Weber et al, 2017;Xu, Mitchell, Liemohn, et al, 2017;Xu, Mitchell, Luhmann, et al, 2017) that DIBRACCIO ET AL.…”

Section: Introductionmentioning

confidence: 99%

The Twisted Configuration of the Martian Magnetotail: MAVEN Observations

DiBraccio

Luhmann

Curry

et al. 2018

Geophysical Research Letters

Self Cite

110

View full text Add to dashboard Cite

Measurements provided by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft are analyzed to investigate the Martian magnetotail configuration as a function of interplanetary magnetic field (IMF) BY. We find that the magnetotail lobes exhibit a ~45° twist, either clockwise or counterclockwise from the ecliptic plane, up to a few Mars radii downstream. Moreover, the associated cross‐tail current sheet is rotated away from the expected location for a Venus‐like induced magnetotail based on nominal IMF draping. Data‐model comparisons using magnetohydrodynamic simulations are in good agreement with the observed tail twist. Model field line tracings indicate that a majority of the twisted tail lobes are composed of open field lines, surrounded by draped IMF. We infer that dayside magnetic reconnection between the crustal fields and draped IMF creates these open fields and may be responsible for the twisted tail configuration, similar to what is observed at Earth.

show abstract

“…Differentiating between these cases allows us to determine which locations around Mars are shielded from or exposed to solar wind influence and provides insight into where and how ion outflow may occur. Magnetic topology at Mars has therefore been the subject of many studies, including several providing statistical maps of topology (Brain et al, ; Weber et al, ; Xu et al, ) and many using topological analysis to support case studies of interesting phenomena in the Martian magnetosphere (e.g., Brain et al, ; Dubinin, Fraenz, Woch, Winnigham, et al, ; Eastwood et al, ; Frahm et al, ; Mitchell et al, )…”

Section: Introductionmentioning

confidence: 99%

The Influence of Solar Wind Pressure on Martian Crustal Magnetic Field Topology

Weber

Brain

Mitchell

et al. 2019

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

We present a study of changes in Martian magnetic topology induced by upstream solar wind ram pressure variations. Using electron energy spectra and pitch angle distributions measured by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we classify the topology of magnetic field lines in the Martian space environment across a range of solar wind conditions. We find that during periods of high solar wind dynamic pressure, draped fields are pushed to lower altitudes on the dayside of the planet, compressing closed fields. At the same time, open topology becomes more prevalent on the nightside due to the broadening of crustal cusp regions. The result is a decrease in closed topology at all locations around Mars, suggesting that the Martian ionosphere becomes significantly more exposed to solar wind energy input during high solar wind pressure. This could likely contribute to elevated levels of ion escape during these periods.

show abstract

Characterization of Low‐Altitude Nightside Martian Magnetic Topology Using Electron Pitch Angle Distributions

Cited by 65 publications

References 34 publications

The Morphology of the Topside Martian Ionosphere: Implications on Bulk Ion Flow

The Morphology of the Topside Martian Ionosphere: Implications on Bulk Ion Flow

The Twisted Configuration of the Martian Magnetotail: MAVEN Observations

The Influence of Solar Wind Pressure on Martian Crustal Magnetic Field Topology

Contact Info

Product

Resources

About