A5084012159- Astro and Planetary Science
- Planetary Science and Exploration
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Space Science and Extraterrestrial Life
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Earthquake Detection and Analysis
- Space Exploration and Technology
- Stellar, planetary, and galactic studies
- Space exploration and regulation
- Global Energy and Sustainability Research
- Spaceflight effects on biology
- Space Satellite Systems and Control
- Gas Dynamics and Kinetic Theory
- Inertial Sensor and Navigation
- Radiative Heat Transfer Studies
- Thermography and Photoacoustic Techniques
- Atmospheric Ozone and Climate
- Calibration and Measurement Techniques
- Laser-induced spectroscopy and plasma
- Gamma-ray bursts and supernovae
- Geophysical and Geoelectrical Methods
- Scientific Research and Discoveries
- Particle Dynamics in Fluid Flows
Goddard Space Flight Center
2015-2025
University of Maryland, College Park
2015-2025
Deleted Institution
2020
National Institute of Aerospace
2018
University of Michigan
2005-2015
Michigan United
2010
Abstract Two Mars Atmosphere and Volatile EvolutioN magnetic field sensors sample the ambient at outer edge of each solar array. We characterized relatively minor spacecraft‐generated fields using in‐flight subsystem tests spacecraft maneuvers. Dynamic associated with power (≤1 nT) are compensated for engineering telemetry to identify active array circuits monitor their electrical current production. Static monitored roll Accuracy measurement environmental is demonstrated by comparison...
Abstract The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been continuously observing the variability of solar soft X‐rays EUV irradiance, monitoring upstream wind interplanetary magnetic field conditions measuring fluxes energetic ions electrons since its arrival to Mars. In this paper, we provide a comprehensive overview space weather events observed during first ∼1.9 years science mission, which includes description heliospheric sources activity. To illustrate variety...
Abstract Measurements provided by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft are analyzed to investigate Martian magnetotail configuration as a function of interplanetary magnetic field (IMF) B Y . We find that lobes exhibit ~45° twist, either clockwise or counterclockwise from ecliptic plane, up few radii downstream. Moreover, associated cross‐tail current sheet is rotated away expected location for Venus‐like induced based on nominal IMF draping. Data‐model comparisons...
Abstract Mars, being a small planet with tenuous atmosphere, does not have sharp boundary between regions dominated by solar wind plasma and planetary plasma. Instead, this transition is typically extended, allowing the interplanetary magnetic field (IMF) to penetrate into Martian ionosphere. However, depth of penetration well understood. Using 6 years MAVEN data, we statistically assess locations where exists dominance versus cold (1 eV), thermal pressure better understand reach IMF. We...
Abstract The Martian magnetosphere is a product of the interaction Mars with interplanetary magnetic field and supersonic solar wind. location bow shock has been previously modeled as conic sections using data from spacecraft such Phobos 2, Global Surveyor, Express. Atmosphere Volatile EvolutioN (MAVEN) mission arrived in orbit about November 2014 resulting thousands crossings to date. We identify over 1,000 crossings. model three‐dimensional surface accommodating asymmetry caused by crustal...
The Martian interaction with the solar wind leads to formation of a bow shock upstream planet. dynamics appear complex, due combined influence external and internal drivers. extreme ultraviolet fluxes magnetosonic Mach number are known major drivers location, while other possible is less constrained or unknown such as crustal magnetic fields, dynamic pressure, Interplanetary Magnetic Field (IMF) intensity, orientation. In this study, we compare main based on several methods published...
Magnetic clouds observed with the Wind and ACE spacecraft are fit static, linear force‐free cylinder model to obtain estimates of chirality, fluxes, magnetic helicity each event. The fastest (MCs) shown carry most flux helicity. We calculate net cumulative which measures difference in right‐ left‐handed contained MCs over time. does not average zero; rather, a strong bias develops solar cycle, dominated by largest events cycle 23: Bastille Day 2000 28 October 2003. majority (“slow” events, 〈...
Oxygen charge states measured by in situ instrumentation have long been used as a powerful diagnostic of the solar corona and to discriminate between different wind regimes, both because they freeze very close Sun, oxygen element abundance is comparatively high, allowing for statistically relevant measures. Like oxygen, carbon also rather abundant freezes Sun. Here, we show an analysis ionic states. First, through auditory Fourier measurements ion composition ACE/SWICS that some ratios are...
We present a novel procedure for deriving the physical properties of coronal mass ejections (CMEs) in corona. Our methodology uses situ measurements ionic charge states C, O, Si, and Fe heliosphere interprets them context model early evolution interplanetary CME (ICME) plasma, between 2 5 R☉. find that data are best fit by an consists initial heating followed expansion ultimately results cooling. The profile is consistent with compression plasma due to flare reconnection jets cooling...
The recent solar minimum with very low activity provides us a unique opportunity for validating wind models. During CR2077 (2008 November 20 through December 17), the number of sunspots was near absolute cycle 23. For this rotation, we perform multi-spacecraft validation study recently developed three-dimensional, two-temperature, Alfvén-wave-driven global model (a component within Space Weather Modeling Framework). By using in situ observations from Solar Terrestrial Relations Observatory...
In the present work, we calculate evolution of charge state distribution within fast solar wind. We use temperature, density, and velocity profiles predicted by Cranmer et al. to ionization history most important heavy elements in corona wind: C, N, O, Ne, Mg, Si, S, Fe. The each is calculated from source region lower chromosphere final freeze-in point. show that wind causes plasma experience significant departures equilibrium at very low heights, well inside field view (within 0.6 Rsun...
Abstract We report on the complex nature of induced Martian magnetotail using simultaneous magnetic field and plasma measurements from Mars Atmosphere Volatile EvolutioN (MAVEN) spacecraft. Two case studies are analyzed which we identify (1) repetitive loading unloading tail flux as magnitude changes dramatically, exhibiting signatures similar to substorm activity within intrinsic magnetospheres; (2) multiple current sheet crossings indicative flapping; (3) tailward flowing high‐energy...
Abstract Direct interaction between the solar wind (SW) and Martian upper atmosphere forms a characteristic region, called induced magnetosphere magnetosheath ionosphere. Since SW deceleration due to increasing mass loading by heavy ions plays an important role in formation, ion composition is also expected change around boundary (IMB). Here we report on relations of IMB, (ICB), pressure balance based statistical analysis about 8 months simultaneous ion, electron, magnetic field observations...
Abstract NASA's Parker Solar Probe (PSP) mission is currently investigating the local plasma environment of inner heliosphere (<0.25 R ⊙ ) using both in situ and remote sensing instrumentation. Connecting signatures microphysical particle heating acceleration processes to macroscale heliospheric structure requires sensitive measurements electromagnetic fields over a large range physical scales. The FIELDS instrument, which provides PSP with corona, includes set three vector magnetometers:...
Abstract During Parker Solar Probe’s first close encounter with the Sun in early 2018 November, a large number of impulsive rotations magnetic field were detected within 50 R s ; these also occurred association short-lived solar wind bursts speed. These features are now called “switchback” events. We examined set switchbacks where boundary transition into and out switchback was abrupt, fast B simultaneous speed changes occurring on timescales less than ∼10 s; thus appear as step...
The activity of the Sun alternates between a solar minimum and maximum, former corresponding to period "quieter" status heliosphere. During minimum, it is in principle more straightforward follow eruptive events wind structures from their birth at throughout interplanetary journey. In this paper, we report analysis origin, evolution, heliospheric impact series transient that took place during second half August 2018, i.e. midst late declining phase Solar Cycle 24. particular, focus on two...
The Martian magnetotail exhibits a highly twisted configuration, shifting in response to changes polarity of the interplanetary magnetic field's (IMF) dawn-dusk (BY) component. Here, we analyze ∼6000 MAVEN orbits quantify degree twisting (θTwist) and assess variations as function (a) strong planetary crustal field location, (b) Mars season, (c) downtail distance. results demonstrate that θTwist is larger for duskward (+BY) IMF orientation majority time. This preference likely due local...
Abstract The response of Mars to the major space weather events called interplanetary coronal mass ejections (ICMEs) is interest for both general planetary solar wind interaction studies and related speculations on their evolutionary consequences—especially with respect atmosphere escape. Various particle field signatures ICMEs have been observed Phobos‐2, Global Surveyor (MGS), Express (MEX), now Atmosphere Volatile EvolutioN (MAVEN). Of these, MAVEN's combined instrumentation orbit...
Abstract The Martian magnetotail is a complex regime through which atmospheric particles are lost to space. Our current understanding of Mars' tail continues develop with the comprehensive particle and field data collected by Mars Atmosphere Volatile EvolutioN (MAVEN). In this work, we identify periods when MAVEN encounters multiple sheet crossings single traversal in order understand dynamics. We apply an analysis technique that has been developed validated using multipoint measurements...
The Martian crustal magnetic anomalies present a varied, asymmetric obstacle to the imposing draped interplanetary field (IMF) and solar wind plasma. Magnetic reconnection, ubiquitous plasma phenomenon responsible for transferring energy changing topology, has been observed throughout magnetosphere. More specifically, reconnection can occur as result of interaction between fields IMF, however, global implications changes overall magnetospheric structure Mars have yet be fully understood....
Abstract An unusually low density solar wind event was observed in December 2022 moving past both Earth and Mars. The source traced back to a coronal hole active region on the Sun's surface. resulting lead development of co‐rotating interaction (CIR) trailing rarefaction that lasted for multiple rotations. Within this structure, conditions, including density, velocity, magnetic field magnitude orientation drastically changed. In study we analyze response Martian ionosphere using MAVEN data...
We develop a new diagnostic technique that utilizes, at the same time, two completely different types of observations—in situ determinations solar wind charge states and high-resolution spectroscopy inner corona—in order to study temperature, density, velocity as function height in corona below plasma freeze-in point. This relies on ability calculate evolution ion composition escapes Sun given profiles distance. The resulting state can be used predict frozen-in well spectral line...
Abstract It has long been a goal of the heliophysics community to understand solar wind variability at heliocentric distances other than 1 AU, especially ∼1.5 AU due not only steepening stream interactions outside but also number missions available there measure it. In this study, we use 35 months and interplanetary magnetic field (IMF) data taken Mars by Atmosphere Volatile EvolutioN (MAVEN) spacecraft conduct an autocorrelation analysis speed, density, dynamic pressure, which is derived...