The response of Martian ionosphere to the passage of Corotating Interaction Region (CIR) of June 2015 is studied using observations from several instruments aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. An intense CIR arrived at Mars on 22 June 2015, during which the upstream solar wind and interplanetary conditions were monitored by the Solar Wind Ion Analyzer (SWIA), Solar Wind Electron Analyzer (SWEA), Magnetometer (MAG), and Solar Energetic Particle (SEP) instruments aboard MAVEN. The CIR event was characterized by enhancements in solar wind density, velocity, and dynamic pressure, and increased & fluctuating interplanetary magnetic field, and was associated with enhanced fluxes of solar energetic particles. The Langmuir Probe and Waves (LPW) instrument onboard MAVEN provided the ionospheric observations such as electron density and electron temperature during this period. The dayside ionosphere is significantly compressed only near the peak of solar wind dynamic pressure enhancement (~14 nPa). In contrast, on the nightside, the electron density remains depleted for a longer period of time. The electron temperatures are also enhanced during the period of electron depletion on the nightside. The STATIC (Suprathermal and Thermal Ion Composition) measurements show enhanced fluxes of suprathermal heavy ions in the Martian exosphere during CIR period, and evidences for enhanced tailward flow of these pickup ions. The analysis suggests that the nightside ionosphere is primarily controlled by the precipitating solar energetic particles and pickup ions transported across the Martian terminator, and depletes significantly when the heavy ion flux in the exosphere enhances.
Lower atmospheric global dust storms affect the small- and large-scale weather and variability of the whole Martian atmosphere. Analysis of the CO$_2$ density data from the Neutral Gas and Ion Mass Spectrometer instrument (NGIMS) on board NASA's Mars Atmosphere Volatile EvolutioN (MAVEN) spacecraft show a remarkable increase of GW-induced density fluctuations in the thermosphere during the 2018 major dust storm with distinct latitude and local time variability. The mean thermospheric GW activity increases by a factor of two during the storm event. The magnitude of relative density perturbation…
A comprehensive study of Nitric oxide (NO) chemistry in the Martian upper atmosphere is restricted due to the lack of requisite measurements. NO is an abundant form of odd nitrogen species in the Martian lower atmosphere and its density depends on several photochemical processes. We have developed a photochemical model to study the NO density in the dayside of Martian upper atmosphere by accounting for various production and loss mechanisms. By utilizing the Neutral Gas and Ion Mass Spectrometer (NGIMS) on-board Mars Atmosphere and Volatile Evolution (MAVEN) mission measured neutral and ion de…
First estimations of Gravity Wave Potential Energy (GWPE) for the Martian thermosphere are reported herein using the height profile of CO2 density derived temperature fluctuations for different Martian seasons during the 33rd Martian year. Explicit diurnal evolution of GWPE (for 52o to 73o latitude bin) with a post sunset maximum is delineated for summer. The higher values of GWPE are observed during morning, compared to post mid-night (35 o to 55 o latitude bin) for summer. As the latitude increases from 16 o to 45 o, GWPE (1-4 LT bin) is found to be nearly doubled for summer. Further, GWPE e…
The dearth of observations between 1 au and 3 au limits our understanding of energetic particle acceleration processes in interplanetary space. We present the first-of-their-kind observations of the energetic particle acceleration in a Corotating Interaction Region (CIR) using data from two vantage points, 1 au (near Earth) and 1.5 au (near Mars). The CIR event of June 2015 was observed by the particle detectors aboard the Advanced Composition Explorer (ACE) satellite as well as the SEP (Solar Energetic Particle) instrument aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft s…
Atmospheric gravity (buoyancy) waves (GWs) are of great importance for the energy and momentum budget of all planetary atmospheres. Propagating upward waves carry energy and momentum from the lower atmosphere to thermospheric altitudes and re-distribute them there. On Mars, GWs dominate the variability of the thermosphere and ionosphere. We provide a comprehensive climatology of Martian thermospheric GW activity at solar minimum (end of Solar Cycle 24) inferred from measurements by Neutral Gas and Ions Mass Spectrometer on board Mars Atmosphere and Volatile EvolutioN (NGIMS/MAVEN). The results…
Impacting the dayside Martian ionosphere from above and below: Effects of the impact of CIRs and ICMEs close to aphelion (April 2021) and during dust storms (June-July 2022) seen with MAVEN ROSE
We analyzed 44 passes of the MAVEN spacecraft through the magnetosphere, arranged by the angle between electric field vector and the projection of spacecraft position radius vector in the YZ plane in MSE coordinate system ($θ$ E ). All passes were divided into 3 angular sectors near 0°, 90° and 180° $θ$ E angles in order to estimate the role of IMF direction in plasma and magnetic properties of dayside Martian magnetosphere. The time interval chosen was from January 17 through February 4, 2016 when MAVEN was crossing the dayside magnetosphere at SZA ~ 70°. Magnetosphere as the region with prev…
Investigation of Martian UV Dayglow Emissions in the Southern Hemisphere during Solar Quiet-time Conditions: Insights from Multi-year MAVEN/IUVS Observations
Solar cycle 24 is one of the weakest solar cycles recorded, but surprisingly the declining phase of it had a slow CME which evolved without any low coronal signature and is classified as a stealth CME which was responsible for an intense geomagnetic storm at Earth (Dst = -176 nT). The impact of this space weather event on the terrestrial ionosphere has been reported. However,the propagation of this CME beyond 1 au and the impact of this CME on other planetary environments have not been studied so far. In this paper, we analyse the data from Sun-Earth L1 point as well as from the Martian orbit …
We report on the local structure of the Martian subsolar Magnetic Pileup Boundary (MPB) from minimum variance analysis of the magnetic field measured by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft for six orbits. In particular, we detect a well defined current layer within the MPB and provide a local estimate of its current density which results in a sunward Hall electric force. This force accounts for the deflection of the solar wind ions and the acceleration of electrons which carry the interplanetary magnetic field through the MPB into the Magnetic Pileup Region. We find t…
The comprehensive suite of scientific instruments with high temporal resolution measurements on the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft allowed studies of the structure and properties of the dayside magnetosphere of Mars. The dayside plasma envelope was found on first Mars orbiters (Vaisberg et al., 1976, Gringauz et al., 1976), but only the high temporal and mass resolutions of MAVEN instruments allowed investigations of the structure and processes of plasma of the dayside magnetosphere, the plasma layer which exists between shocked solar wind and ionosphere (Vaisberg et…
Depression in magnetic field strength with a scale below one proton gyroradius is referred to as kinetic-size magnetic hole (KSMH). KSMHs are frequently observed near terrestrial space environments and are thought to play an important role in electron energization and energy dissipation in space plasmas. Recently, KSMHs have been evidenced in the Venusian magnetosheath. However, observations of KSMHs in other planetary environments are still lacking. In this study, we present the in situ detection of KSMHs in Martian magnetosheath using Mars Atmosphere and Volatile EvolutioN (MAVEN) for the fi…
The first estimation of the incompressible energy cascade rate at magnetohydrodynamic (MHD) scales is obtained in the plasma upstream of the Martian bow shock, using MAVEN observations and an exact relation derived for MHD turbulence. The energy cascade rate is computed for events with and without proton cyclotron wave (PCW) activity, for time intervals when MAVEN was in the solar wind with no magnetic connection to the bow shock. It is shown that the nonlinear cascade of energy at the MHD scales is slightly amplified when PCWs are present in the plasma. The analysis of the normalized cross he…
August 1 to November 15, 2016 period was characterized by the presence of Corotating Interaction Regions (CIRs) and a few weak Coronal Mass Ejections (CMEs) in the heliosphere. In this study we show recurrent energetic electron and proton enhancements observed near Earth (1 AU) and Mars (1.43-1.38 AU) during this period. The observations near Earth are using data from instruments aboard ACE, SOHO, and SDO whereas those near Mars are by the SEP, SWIA, and MAG instruments aboard MAVEN. During this period, the energetic electron fluxes observed near Earth and Mars showed prominent periodic enhanc…
We study roles of the thermosphere and exosphere on the Martian ionospheric structure and ion escape rates in the process of the solar wind-Mars interaction. We employ a four-species multifluid MHD (MF-MHD) model to simulate the Martian ionosphere and magnetosphere. The $cold$ thermosphere background is taken from the Mars Global Ionosphere Thermosphere Model (M-GITM) and the $hot$ oxygen exosphere is adopted from the Mars exosphere Monte Carlo model - Adaptive Mesh Particle Simulator (AMPS). A total of four cases with the combination of 1D (globally averaged) and 3D thermospheres and exospher…
We present a statistical analysis on the variability of the incompressible energy cascade rate in the solar wind around Mars, making use of an exact relation for fully developed turbulence and more than five years of Mars Atmosphere and Volatile EvolutioN (MAVEN) observations. Using magnetic field and plasma data, we compute the energy cascade rate in the magnetohydrodynamics (MHD) scales in the pristine solar wind. From our statistical results, we conclude that the incompressible energy cascade rate decreases as the Martian heliocentric distance increases, for each of the three explored Marti…
Since the first \emph{in-situ} measurements of the altitude profile of upper atmospheric density and composition carried out by the Viking lander missions during 1976, similar data were continuously gathered by MAVEN and MOM spacecraft orbiting Mars since September 2014 with a mass spectrometer and other related payloads. Using near-simultaneous observations by the two orbiters, we show that both data sets confirm significant day-to-day variations of Argon ($Ar$) density profiles in the Martian thermosphere/exosphere during 1-15 June 2018 when the solar EUV radiation did not show any appreciab…
Thermal (<1 eV) electron density measurements, derived from the Mars Atmosphere and Volatile Evolution's (MAVEN) Langmuir Probe and Waves (LPW) instrument, are analyzed to produce the first statistical study of the thermal electron population in the Martian magnetotail. Coincident measurements of the local magnetic field are used to demonstrate that close to Mars, the thermal electron population is most likely to be observed at a cylindrical distance of ~1.1 Mars radii (RM) from the central tail region during times when the magnetic field flares inward toward the central tail, compared to ~1.3…
In a two-week period between February and March of 2015, a series of interplanetary coronal mass ejections (ICMEs) and (solar energetic particles) SEPs made contact with 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, unusually high local electron densities and high flow velociti…
Dayside magnetosphere of Mars is a thin layer with usually increased magnetic field and heated planetary ions between the magnetosheath and the ionosphere. The Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft provided, for the first time, high temporal and spatial resolution measurements enabling to study the structure of this region. The region was given several names including the boundary layer, the plasma mantle, and magnetosphere. The outer boundary of this region was called magnetopause, ionopause, ion composition boundary and pile-up boundary (see Espley, 2018). We anal…
We present fast algorithms to automatically estimate the statistical position of the bow shock from spacecraft data, using existing analytical two-dimensional (2D) and three-dimensional (3D) models of the shock surface. We derive expressions of the standoff distances in 2D and 3D and of the normal to the bow shock at any given point on it. Two simple bow shock detection algorithms are constructed, one solely based on a geometrical predictor from existing models, the other using this predicted position to further refine it with the help of magnetometer data, an instrument flown on many planetar…
A case study on the impact of interplanetary coronal mass ejection on the Martian O(1S) 557.7 nm dayglow emission using ExoMars TGO/NOMAD-UVIS observations: First Results
Kelvin-Helmholtz vortices in the Martian +E hemisphere downstream of crustal magnetic anomalies
University of Science and Technology of China（中国科学技术大学）；The University of Hong Kong（香港大学）；National Space Science Center, Chinese Academy of Sciences（中国科学院国家空间科学中心）；Harbin Institute of Technology, Shenzhen（哈尔滨工业大学（深圳））；Space Research Institute, Austrian Academy of Sciences（奥地利科学院空间研究所）
Characterizing the current systems in the Martian ionosphere
Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences（中国科学院地质与地球物理研究所）；College of Earth and Planetary Sciences, University of Chinese Academy of Sciences（中国科学院大学地球与行星科学学院）；School of Space and Environment, Beihang University（北京航空航天大学空间与环境学院）；Department of Earth Sciences, ETH Zurich（苏黎世联邦理工学院地球科学系）；Swedish Institute of Space Physics（瑞典空间物理研究所）；Center for Space Physics and Department of Astronomy, Boston University（波士顿大学空间物理中心暨天文学系）；Fudan University（复旦大学）；The Shanghai Institute for Mathematics and Interdisciplinary Sciences（上海数学与交叉学科研究院）；Planetary Environmental and Astrobiological Research Laboratory, School of Atmospheric Sciences, Sun Yat-sen University（中山大学大气科学学院行星环境与天体生物学研究实验室）
We present observations from the Rosetta Plasma Consortium of the effects of stormy solar wind on comet 67P/Churyumov-Gerasimenko. Four corotating interaction regions (CIRs), where the first event has possibly merged with a CME, are traced from Earth via Mars (using Mars Express and MAVEN) and to comet 67P from October to December 2014. When the comet is 3.1-2.7 AU from the Sun and the neutral outgassing rate $\sim10^{25}-10^{26}$ s$^{-1}$ the CIRs significantly influence the cometary plasma environment at altitudes down to 10-30 km. The ionospheric low-energy \textcolor{black}{($\sim$5 eV) pl…
Knowledge of Mars's ionosphere has been significantly advanced in recent years by observations from Mars Express (MEX) and lately MAVEN. A topic of particular interest are the interactions between the planet's ionospheric plasma and its highly structured crustal magnetic fields, and how these lead to the redistribution of plasma and affect the propagation of radio waves in the system. In this paper, we elucidate a possible relationship between two anomalous radar signatures previously reported in observations from the MARSIS instrument on MEX. Relatively uncommon observations of localized, ext…
Mars Exospheric Neutral Composition Analyzer (MENCA) of Mars Orbiter Mission (MOM) measures the \emph{in-situ} neutral upper atmospheric constituents of Mars. Martian lower atmosphere predominated by the presence of $CO_2$ which photo-dissociates into atomic oxygen ($O$) in higher altitudes much near the exobase. Atomic $O$ plays a significant role in invoking the stronger presence of $O_2^+$ in the Martian ionosphere. Primary photo-dissociative species $CO_{2}$, crossover their neutral abundance with atomic $O$ in the collisionless heterogenous atmosphere with varying local solar conditions. …
Simultaneous Mars-orbit observations reveal Kelvin-Helmholtz instability-driven bulk atmospheric ion escape
Boston University（波士顿大学）；Institute for Advanced Study, Princeton（普林斯顿高等研究院）；Catholic University of America（美利坚天主教大学）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；University of Iowa（爱荷华大学）；University of Colorado（科罗拉多大学）；University of California, Berkeley（加州大学伯克利分校）
