Article
Engineering, Aerospace
Shahd A. AlMutawa, Tariq Majeed, Omar AlAryani, Stephen. W. Bougher, Paul Withers, Syed A. Haider, Achim A. Morschhauser
Summary: Localized crustal magnetization in the heavily cratered southern hemisphere of Mars interacts with the solar wind magnetic field to form magnetic cusps, where energetic electrons accelerate downward to create auroras. Collisions between plasma and the neutral atmosphere at these cusps result in complex ionospheric structures over regions of magnetic anomalies.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Astronomy & Astrophysics
P. Garnier, C. Jacquey, X. Gendre, V Genot, C. Mazelle, X. Fang, J. R. Gruesbeck, B. Sanchez-Cano, J. S. Halekas
Summary: This study provides a detailed analysis of the influence of crustal magnetic fields on the location of Martian shocks. The results demonstrate that the influence of crustal fields on the shock is significant and complex, showing a seasonal variation and correlation with the Total Electronic Content. This study reveals a large-scale coupling between crustal fields, ionosphere, and shocks.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
I de Oliveira, M. Fraenz, E. Echer, A. Franco
Summary: The study investigates the advection of Mars' crustal magnetic fields by ionospheric plasma flow, showing statistical and observational evidence of displacement towards the night-side of the planet. The displacement increases exponentially with altitude, potentially due to dynamic pressure of ionospheric plasma flow.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
F. Duru, R. A. Frahm, D. Hughes, T. Caplice, J. Pierce, H. Madanian
Summary: Steep electron density depletions in the Martian ionosphere are important factors in plasma escape. Over the past 12 years, research has identified more than 200 cases of density depletions in the Martian ionosphere, with fluctuations observed in the electron density profiles obtained from the Mars Express spacecraft. These depletions occur at different altitudes and during both day and night, with a higher frequency in the southern hemisphere. Possible mechanisms for these depletions include localized electric or magnetic fields and plasma escape along magnetic field lines.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Geosciences, Multidisciplinary
Z. Z. Guo, H. S. Fu, J. B. Cao, K. Fan, Z. H. Yao, Y. Y. Liu, Z. Z. Chen, Z. Wang, X. Y. Liu, Y. Xu, C. Mazelle, D. L. Mitchell
Summary: This study reports two events of betatron cooling in the Martian magnetotail using MAVEN measurements, successfully reproducing these processes quantitatively with an analytical model. The results demonstrate the betatron-cooling effect beyond the Earth and provide insights into electron dynamics in the planetary magnetosphere.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Shengxia Gong, Mark Wieczorek
Summary: Magnetic field measurements on Mars indicate strong crustal magnetic anomalies, with differences in magnetization depths between the northern and southern hemispheres attributed to distinct origins of magnetic materials. The study suggests that the deep remanent magnetization in the southern hemisphere may be a result of excavation of strong primordial magnetic materials from the Borealis impact basin in the northern hemisphere.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2021)
Review
Astronomy & Astrophysics
S. A. Haider, K. K. Mahajan, S. W. Bougher, N. M. Schneider, J. Deighan, S. K. Jain, J. C. Gerard
Summary: This article reviews the latest research on Martian auroras, including observations obtained by instruments aboard Mars Express and the MAVEN mission, as well as observations of Martian auroras by the MARSIS instrument. Additionally, the article reviews various models of Martian auroras.
SPACE SCIENCE REVIEWS
(2022)
Article
Astronomy & Astrophysics
Z. Z. Guo, Y. Y. Liu, Z. Wang, Y. Xu
Summary: We analyze the occurrence rates of energetic electron pancake pitch-angle distributions in the Martian space environment using MAVEN data. In the Martian ionosphere, the occurrence rates vary with altitude and location, with higher rates at the edges of strong magnetic fields. In the Martian induced magnetosphere, the occurrence rates differ between the southern and northern magnetosheath regions, and are higher on the dawnside compared to the duskside.
ASTROPHYSICAL JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Roger Wood, Neil Smith
Summary: A magnetized conical shell has interesting properties and can be used in magnetic force microscopy. Only the magnetization component toward the vertex produces a field in a very tall uniformly magnetized shell. The axial component of the resulting field decays inversely with distance and has the same form as the field from an isolated charge.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Astronomy & Astrophysics
Qiong Luo, Yutian Cao, Binbin Ni, Jun Cui, Xing Cao, Xudong Gu
Summary: This study provides a detailed analysis of the occurrence patterns of photoelectron butterfly pitch-angle distributions in the Martian ionosphere based on pitch-angle-resolved electron fluxes recorded by the Mars Atmosphere and Volatile Evolution spacecraft over 5 years. The findings suggest that Martian photoelectron butterfly PADs are more likely to occur near moderate crustal magnetic fields and on the nightside.
ASTROPHYSICAL JOURNAL
(2022)
Article
Geosciences, Multidisciplinary
Z. Z. Chen, H. S. Fu, Z. Wang, Z. Z. Guo, Y. Xu, C. M. Liu
Summary: This study presents the first observation of a magnetic flux rope (MFR) inside an electron diffusion region (EDR), confirming its crucial role in magnetic reconnection. By observing and analyzing the structure and energy dissipation of MFR, it helps to understand the modulation of the electric field in EDR by MFR.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Chemistry, Physical
Felix Buettner, Bastian Pfau, Marie Boettcher, Michael Schneider, Giuseppe Mercurio, Christian M. Guenther, Piet Hessing, Christopher Klose, Angela Wittmann, Kathinka Gerlinger, Lisa-Marie Kern, Christian Strueber, Clemens von Korff Schmising, Josefin Fuchs, Dieter Engel, Alexandra Churikova, Siying Huang, Daniel Suzuki, Ivan Lemesh, Mantao Huang, Lucas Caretta, David Weder, John H. Gaida, Marcel Moeller, Tyler R. Harvey, Sergey Zayko, Kai Bagschik, Robert Carley, Laurent Mercadier, Justine Schlappa, Alexander Yaroslavtsev, Loic Le Guyarder, Natalia Gerasimova, Andreas Scherz, Carsten Deiter, Rafael Gort, David Hickin, Jun Zhu, Monica Turcato, David Lomidze, Florian Erdinger, Andrea Castoldi, Stefano Maffessanti, Matteo Porro, Andrey Samartsev, Jairo Sinova, Claus Ropers, Johan H. Mentink, Bertrand Dupe, Geoffrey S. D. Beach, Stefan Eisebitt
Summary: Time-resolved X-ray scattering was used to demonstrate the ultrafast 300 ps topological phase transition to a skyrmionic phase, mediated by the formation of a transient topological fluctuation state. The emergence of an extended topological phase containing many magnetic skyrmions was observed within picoseconds, with the nucleation process mediated by the transient topological fluctuation state induced by a time-reversal symmetry-breaking perpendicular magnetic field.
Article
Geosciences, Multidisciplinary
JunFeng Qin, Hong Zou, Yoshifumi Futaana, YuGuang Ye, YongQiang Hao, Erling Nielsen, JinSong Wang
Summary: This study investigates the detailed configurations of the Martian nightside ionosphere in crustal magnetic field cusp regions using high-spatial-resolution total electron content (TEC) data obtained by Mars Advanced Radar for Subsurface and Ionospheric Sounding. It finds that the double-peak structures of TEC values are frequently observed in strong crustal magnetic field cusp regions, with higher TECs in the periphery than in the central areas. The difference in electron fluxes precipitating in central and peripheral areas of the cusp regions is responsible for the observed TEC double-peak structures.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Astronomy & Astrophysics
J. W. Gao, Z. J. Rong, Lucy Klinger, X. Z. Li, D. Liu, Y. Wei
Summary: This study proposed a new spherical harmonic model of the crustal magnetic field of Mars based on data from MGS and MAVEN spacecraft. By minimizing external field influences and using a least squares technique, the model achieved a higher accuracy compared to previous models, especially at low altitudes. The new model may benefit future studies on the Martian crustal field and its interaction with the solar wind.
EARTH AND SPACE SCIENCE
(2021)
Article
Astronomy & Astrophysics
S. D. Shuvalov, E. E. Grigorenko
Summary: By studying the structures observed near the Martian aphelion, it is found that these structures are consistent with the Short Large-Amplitude Magnetic Structures (SLAMS) commonly detected in the foreshock regions of magnetized and unmagnetized bodies throughout the Solar system. Further analysis shows that the observed SLAMS-like structures are formed by the ion cyclotron resonance between plasma waves propagating along the IMF and the back-streaming solar wind ions and exospheric ions.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Geosciences, Multidisciplinary
A. R. Poppe, D. A. Brain, Y. Dong, S. Xu, R. Jarvinen
Summary: Ion outflow is a significant factor contributing to atmospheric loss at Mars over geologic time. Studies have shown that regions within crustal magnetic fields on Mars' nightside may accelerate electrons into the atmosphere and enhance ionospheric escape. The presence of strong open crustal magnetic fields could lead to more than double the ionospheric escape flux compared to regions with no crustal fields, indicating their potential significant contribution to Mars' atmospheric loss.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
C. F. Bowers, J. A. Slavin, G. A. DiBraccio, G. Poh, T. Hara, S. Xu, D. A. Brain
Summary: By analyzing data from the MAVEN spacecraft, researchers have identified 121 magnetic flux ropes on Mars, formed via different mechanisms and impacting the Martian plasma environment. The study demonstrates that the formation mechanism of a flux rope influences its impact on the Martian magnetospheric and atmospheric environment.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Astronomy & Astrophysics
R. D. Jolitz, C. F. Dong, A. Rahmati, D. A. Brain, C. O. Lee, R. J. Lillis, S. M. Curry, B. M. Jakosky
Summary: This study investigates the effects of extreme space weather events releasing high-energy particles on the Martian atmosphere, highlighting the significant influence of curvature and gradient drifts on particle precipitation and predicting changes in differential flux with energy and SEP electron spectra. The model estimates suggest that a portion of incident flux precipitates into the Mars atmosphere, with nonadiabatic transport mechanisms playing a significant role in precipitation.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
N. M. Schneider, Z. Milby, S. K. Jain, J. C. Gerard, L. Soret, D. A. Brain, T. Weber, Z. Girazian, J. McFadden, J. Deighan, B. M. Jakosky
Summary: MAVEN's Imaging Ultraviolet Spectrograph has identified 278 discrete aurora events on Mars, with the brightest and most frequent occurrences located around strong crustal fields in the southern hemisphere. These events primarily occur in the evening and are influenced by favorable orientations of the interplanetary magnetic field, lasting for hours each night and potentially visible to future astronauts.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Takuya Hara, Zesen Huang, David L. Mitchell, Gina A. DiBraccio, David A. Brain, Yuki Harada, Janet G. Luhmann
Summary: We analyzed data from MAVEN and VEX to study the characteristics and formation processes of magnetic flux ropes observed in the nightside magnetosphere of Mars and Venus. Our analysis showed that there is no significant difference in the axial orientation of flux ropes between Mars and Venus. However, flux ropes at Venus tend to be observed near the central plasma sheet, while those at Mars are more spread out. Furthermore, the frequency of occurrence of flux ropes is higher in the -E hemisphere and the southern hemisphere of Mars, indicating the significant role of crustal magnetic fields in their generation.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Robin Ramstad, David A. Brain, Yaxue Dong, Jasper S. Halekas, James P. McFadden, Jared Espley, Bruce Jakosky
Summary: In this study, the distributions of H+, O+, and O-2(+) near Mars were determined using phase-space mapping and line integration of energetic neutral atom (ENA) production and loss rates. The results show that the H+ flux is mainly from the upstream solar wind, while the O-ENAs are dominated by a near-isotropic low-energy population originating in the top-side ionosphere. Synthetic ENA observations provide valuable insights into the near-Mars space environment, including the planet's plasma environment and exosphere.
ASTROPHYSICAL JOURNAL
(2022)
Article
Geosciences, Multidisciplinary
Shaosui Xu, David L. Mitchell, James P. McFadden, Nicholas M. Schneider, Zachariah Milby, Sonal Jain, Tristan Weber, David A. Brain, Gina A. DiBraccio, Jasper Halekas, Suranga Ruhunusiri, Christian Mazelle, Robert J. Lillis, Ben Johnston
Summary: This study establishes empirical criteria and enables a direct statistical comparison between discrete aurorae and their source electron events, bridging the gap in previous research and facilitating collaboration among different Mars missions and comparative planetary studies of discrete aurora.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Kotaro Sakakura, Kanako Seki, Shotaro Sakai, Ryoya Sakata, Hiroyuki Shinagawa, David A. Brain, James P. McFadden, Jasper S. Halekas, Gina A. DiBraccio, Bruce M. Jakosky, Naoki Terada, Takashi Tanaka
Summary: Based on observations and numerical models, this study investigated the formation mechanism of a molecular ion plume on Mars and its contribution to ion escape. The results show that the plume is formed by the deep penetration of the solar wind-induced electric field under strong solar wind dynamic pressure conditions. This study also found that CO2+ plume events tend to occur under high solar wind dynamic pressure and strong electric field conditions, while O-2(+) plumes can be formed even under weak solar wind conditions.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Geosciences, Multidisciplinary
Robert J. Lillis, Justin Deighan, David Brain, Matthew Fillingim, Sonal Jain, Michael Chaffin, Scott England, Greg Holsclaw, Krishnaprasad Chirakkil, Hessa Al Matroushi, Fatma Lootah, Hoor Al Mazmi, Ed Thiemann, Frank Eparvier, Nick Schneider, Shannon Curry
Summary: This study presents the first measurements and observations of discrete aurora on Mars in the extreme ultraviolet and far ultraviolet ranges. The results reveal that auroral emissions are commonly detected on the nightside images and exhibit visible patterns shifting within a short timeframe. The occurrence of aurora is found to be most frequent in regions of open magnetic topology, with the brightest aurora observed where crustal magnetic fields are strongest. The study also categorizes the discrete auroral morphology into three types and presents the first disk-averaged spectrum of discrete aurora.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Michael S. Chaffin, Christopher M. Fowler, Justin Deighan, Sonal Jain, Greg Holsclaw, Andrea Hughes, Robin Ramstad, Yaxue Dong, Dave Brain, Hoor AlMazmi, Krishnaprasad Chirakkil, John Correira, Scott England, J. Scott Evans, Matt Fillingim, Rob Lillis, Fatma Lootah, Susarla Raghuram, Jim McFadden, Jasper Halekas, Jared Espley, Nick Schneider, Majd Mayyasi, Christina O. Lee, Shannon Curry, Hessa AlMatroushi
Summary: Multiple definitive observations of localized patchy proton aurora at Mars are reported in this study, along with the characterization of the plasma environment using measurements from other missions. Multiple mechanisms are required to explain these observations, and further research is needed to understand the impact of these auroral events on Mars atmospheric evolution.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Shaosui Xu, David L. Mitchell, James P. McFadden, Christopher M. Fowler, Kathleen Hanley, Tristan Weber, David A. Brain, Gina A. DiBraccio, Michael W. Liemohn, Robert J. Lillis, Jasper S. Halekas, Suranga Ruhunusiri, Laila Andersson, Christian Mazelle, Shannon M. Curry
Summary: Discrete aurorae have been observed at Mars, and the occurrence rate is found to be influenced by upstream dynamic pressure and interplanetary magnetic field strength. Strong crustal fields are associated with more frequent and intense auroral electron precipitation. This precipitation has significant impact on ionization and plasma density locally.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
R. D. Jolitz, A. Rahmati, D. A. Brain, C. O. Lee, R. J. Lillis, E. Thiemann, F. Eparvier, D. Mitchell, J. Halekas, D. Larson, S. M. Curry, B. M. Jakosky
Summary: Solar extreme ultraviolet (EUV) radiation, solar wind, and solar energetic particles (SEPs) are sources of ionization and heating to the Martian atmosphere. MAVEN's orbit allows it to measure these solar drivers upstream of Mars. By averaging observations over several months, the study found that EUV and solar wind ions are the dominant contributors to energy fluxes, while SEPs play a smaller role. The study also identified the presence of strong and weak coronal mass ejections, which can impact the energy fluxes on the nightside.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Geosciences, Multidisciplinary
H. Madanian, N. Omidi, D. G. Sibeck, L. Andersson, R. Ramstad, S. Xu, J. R. Gruesbeck, S. J. Schwartz, R. A. Frahm, D. A. Brain, P. Kajdic, F. G. Eparvier, D. L. Mitchell, S. M. Curry
Summary: This study investigates the non-planarity of Mars' bow shock and its impact on transient structures near the upstream edge of moving foreshocks caused by slow rotations in the IMF. The structures exhibit a decrease in plasma density and IMF strength within their core, accompanied by a compressional shock layer, consistent with foreshock bubbles. The ion populations responsible for these structures include backstreaming ions and reflected ions with hybrid trajectories.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Shaosui Xu, David L. L. Mitchell, James P. P. McFadden, Christopher M. M. Fowler, Kathleen Hanley, Tristan Weber, David A. A. Brain, Yingjuan Ma, Gina A. A. DiBraccio, Christian Mazelle, Shannon M. M. Curry
Summary: This study utilizes observations from the MAVEN mission to revisit boundaries within the interaction of Mars and the solar wind, proposing new findings regarding the photoelectron boundary (PEB). It is found that the PEB falls within the ion composition boundary and is not a pressure balance boundary. The PEB marks the top of the Mars dayside ionosphere and serves as the interface where the sheath plasma flow deflects around the obstacle going downstream.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Wenyi Sun, Yingjuan Ma, Christopher T. Russell, Janet Luhmann, Andrew Nagy, David Brain
Summary: Although photochemistry-enabled escape of oxygen is dominant at Mars today, ion outflow, including planetary proton loss, plays an important role in the atmosphere's long-term evolution. Improving the MHD model of Mars to differentiate between planetary and solar wind protons, we find that planetary proton escape rates exceed heavy ion loss rates and solar wind proton inflows. However, the contribution of planetary protons to hydrogen loss is limited. By considering different reactions, we conclude that H-O charge exchange affects low altitude densities while impact ionizations impact escape rates at higher altitudes. This research highlights the need to include specific treatment of proton origins in future studies on the fate of water on Mars.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)