A5086203372- Planetary Science and Exploration
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Space Science and Extraterrestrial Life
- Dust and Plasma Wave Phenomena
- Space Satellite Systems and Control
- Earthquake Detection and Analysis
- Geophysics and Gravity Measurements
- Isotope Analysis in Ecology
- Laser-induced spectroscopy and plasma
- Scientific Computing and Data Management
- Granular flow and fluidized beds
- Cold Atom Physics and Bose-Einstein Condensates
- SAS software applications and methods
- Spaceflight effects on biology
- Material Dynamics and Properties
- Radiation Effects in Electronics
- Astronomical Observations and Instrumentation
- Space Exploration and Technology
- High-pressure geophysics and materials
- Magnetic confinement fusion research
- Geology and Paleoclimatology Research
- Atomic and Subatomic Physics Research
University of Iowa
2016-2025
Laboratory for Atmospheric and Space Physics
2018-2025
University of Colorado Boulder
2023-2024
John Wiley & Sons (United States)
2016
Charles River Laboratories (Netherlands)
2016
Abstract We report on the in‐flight performance of Solar Wind Ion Analyzer (SWIA) and observations Mars‐solar wind interaction made during Mars Atmosphere Volatile EvolutioN (MAVEN) prime mission a portion its extended mission, covering 0.85 Martian years. describe data products returned by SWIA discuss proper handling measurements with different mechanical attenuator states telemetry modes, effects penetrating scattered backgrounds, limited phase space coverage, multi‐ion populations...
Coupling between the lower and upper atmosphere, combined with loss of gas from atmosphere to space, likely contributed thin, cold, dry modern Mars. To help understand ongoing ion Mars Atmosphere Volatile Evolution (MAVEN) spacecraft made comprehensive measurements ionosphere, interactions Sun solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes bow shock magnetosheath, formation widespread diffuse aurora, enhancement pick-up ions....
The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements martian thermosphere ionosphere composition, structure, variability at altitudes down to ~130 kilometers in subsolar region. This altitude range contains diffusively separated upper atmosphere just above well-mixed atmosphere, layer peak extreme ultraviolet heating primary reservoir for atmospheric escape. In situ reveal previously unmeasured populations...
Abstract We utilize suprathermal ion and magnetic field measurements from the Mars Atmosphere Volatile EvolutioN (MAVEN) mission, organized by upstream field, to investigate morphology variability of flows, fields, forces in Mars‐solar wind interaction. employ a combination case studies statistical investigations characterize interaction both quasi‐parallel quasi‐perpendicular regions under high low solar Mach number conditions. For first time, we include detailed investigation temperature...
Abstract Mars Atmosphere and Volatile EvolutioN mission (MAVEN) observes a tenuous but ubiquitous flux of protons with the same energy as solar wind in Martian atmosphere. During high intervals, we observe corresponding negative hydrogen population. The correlation between penetrating fluxes, constant energy, lack charged population at intermediate altitudes implicate products energetic neutral atoms from charge exchange upstream exosphere. These atoms, previously observed form, penetrate...
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 We report Mars Atmosphere and Volatile EvolutioN (MAVEN) observations of electrons, ions, magnetic fields which provide comprehensive demonstration reconnection signatures in the Martian magnetotail. In near‐Mars tail current sheet at X MSO ∼−1.3 R M , trapped electrons with two‐sided loss cones were observed, indicating closed field topology. region, MAVEN observed Hall Marsward bulk flows H + O suggest presence lines tailward from spacecraft. Velocity distribution functions...
Abstract Measurements provided by the Magnetometer and Extreme Ultraviolet Monitor (EUVM) on board Mars Atmosphere Volatile EvolutioN (MAVEN) spacecraft together with atomic H exospheric densities derived from numerical simulations are studied for time interval October 2014 up to March 2016. We determine proton cyclotron waves (PCWs) occurrence rate observed upstream at different times. also study relationship temporal variabilities of high‐altitude Martian hydrogen exosphere solar EUV flux...
Abstract We characterize low‐frequency plasma waves in the Martian magnetosphere and upstream region by using transport ratios. To compute ratios, we use Mars Atmosphere Volatile EvolutioN mission's (MAVEN) solar wind ion analyzer suprathermal thermal composition instrument measurements of moments magnetometer magnetic field. find that Alfvén are most dominant wave mode magnetosheath. Fast found frequently near bow shock pileup boundary. Mirror slow waves, on other hand, occur much less...
Abstract The identification of magnetic reconnection on the dayside Mars has been elusive owing to lack comprehensive plasma and field measurements. Here we present direct measurements in situ signatures by particles fields package board Atmosphere Volatile EvolutioN (MAVEN) spacecraft over strong crustal southern hemisphere Mars. During a crossing bifurcated current sheet consisting northward southward fields, MAVEN recorded (i) ionospheric photoelectrons trapped closed lines, (ii) Hall...
Abstract We conduct an extended survey of reconnection signatures observed in the Martian magnetotail by Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. Although it is well established that magnetic plays a fundamental role dynamics intrinsic magnetospheres, induced magnetospheres remains poorly understood. Based on comprehensive plasma field measurements MAVEN magnetotail, we first identified 776 current sheet crossings then selected 34 with Hall signatures, which are indicative ion...
Abstract We present preliminary results and interpretations for Mars Atmospheric Volatile EvolutioN (MAVEN) observations of magnetosheath‐ionospheric boundary oscillations at Mars. Using centrifugal force arguments, we first predict that a signature fully rolled up Kelvin‐Helmholtz vortices is sheath ions have bulk motion toward the Sun. The adjacent to vortex should also accelerate speeds higher than mean velocity. while ionospheric are in antisunward, they never attain exceeding ions,...
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...
Abstract Using data from the National Aeronautics and Space Administration Mars Atmosphere Voltatile EvolutioN European Agency Express spacecraft, we show that transient phenomena in foreshock solar wind can directly inject energy into ionosphere of Mars. We demonstrate impact compressive ultralow frequency waves on induced magnetospheres drive compressional, linearly polarized, magnetosonic ionosphere, a localized electromagnetic "ringing" at local proton gyrofrequency. The pulsations heat...
Abstract We characterize turbulence in the Mars plasma environment a global scale for first time by computing spectral indices magnetic field fluctuations (slopes power spectra) and determining how they vary with frequency different regions. In magnetosheath, unlike solar wind, we find an absence of inertial range which has index value equal to Kolmogorov scaling −5/3. Instead, as observed magnetosheaths other planets, that transition from low negative values close −0.5 at frequencies (<...
Abstract We present initial Mars Atmosphere and Volatile EvolutioN (MAVEN) observations preliminary interpretation of bulk plasma loss from Mars. MAVEN particle field measurements show that planetary heavy ions derived the Martian atmosphere can escape in form discrete coherent structures or “clouds.” The these clouds are unmagnetized weakly magnetized, have velocities well above speed, lie directly downstream magnetic amplifications, suggesting a “snowplow” effect. This postulated process,...
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 We present Mars Atmosphere and Volatile EvolutioN (MAVEN) observations of Marsward tailward fluxes suprathermal (>25 eV) ions in the near‐Mars (∼1–1.5 radii downstream) magnetotail. Statistical results show that proton flux magnetic field draping pattern are well organized by upstream motional electric direction. observe both significant tightly wrapped lines hemisphere pointed opposite direction to field. These characteristics very similar those observed at Venus. On other hand,...
Abstract We report on narrowband electromagnetic waves at frequencies between the local electron cyclotron and lower hybrid observed by Mars Atmosphere Volatile EvolutioN (MAVEN) spacecraft in Martian induced magnetosphere. The peaked electric field wave spectra below frequency were first Phobos‐2 magnetosphere, but lack of magnetic data prevented definitive identification mode their generation mechanisms remain unclear. Analysis obtained MAVEN demonstrates that have properties consistent...
Abstract We present topside ionospheric sounding on the nightside of Mars during September 2017 solar event by Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) board Express along with complementary dayside observations from Atmosphere Volatile EvolutioN (MAVEN). The MARSIS MAVEN suggest that (i) bottomside ionosphere was significantly enhanced energetic particles, (ii) peak electron density increased to unusually high values ∼1–2 ×10 4 cm −3 around 120 km altitudes owing...
Machine learning (ML) methods can expand our ability to construct, and draw insight from large datasets. Despite the increasing volume of planetary observations, field has seen few applications ML in comparison other sciences. To support these methods, we propose ten recommendations for bolstering a data-rich future science.
Abstract We present a novel method to determine solar wind proxies from sheath measurements at Mars. Specifically, we develop an artificial neural network (ANN) simultaneously infer seven proxies: ion density, speed, temperature, and interplanetary magnetic field magnitude its vector components, using spacecraft of moments, magnitude, components in the sheath, extreme ultraviolet flux. The ANN was trained tested 3 years data Mars Atmosphere Volatile EvolutioN (MAVEN) spacecraft. When...
Abstract We describe a new method to analyze the properties of plasma waves and apply it observations made upstream from Mars by Atmosphere Volatile EvolutioN (MAVEN) mission. The slow measurement cadence most charged particle instrumentation has limited application analysis techniques based on correlations between magnetic field measurements. show that we can extend frequency range applicability for these techniques, subset remain nearly coherent over multiple wave periods, subsampling...
Abstract Magnetic reconnection is often suggested to be implicated in a variety of dynamic phenomena observed the complex magnetosphere Mars. We present first global survey ion jets within current sheets, which are thought as primary product magnetic reconnection, with Mars Atmosphere and Volatile EvolutioN (MAVEN) data obtained on dayside nightside Martian magnetosphere. develop fully automated algorithm efficiently reliably identify flow velocity deviations during sheet crossings recorded...