A5070521159- Planetary Science and Exploration
- Astro and Planetary Science
- Space Science and Extraterrestrial Life
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Ionosphere and magnetosphere dynamics
- Laser-induced spectroscopy and plasma
- Astrophysics and Star Formation Studies
- Spacecraft and Cryogenic Technologies
- Electrohydrodynamics and Fluid Dynamics
- Spaceflight effects on biology
- Geophysics and Gravity Measurements
- Space Satellite Systems and Control
- Scientific Research and Discoveries
- Space Exploration and Technology
- Atomic and Molecular Physics
- Space exploration and regulation
- Radiation Therapy and Dosimetry
- History and Developments in Astronomy
- Gas Dynamics and Kinetic Theory
- Laser-Plasma Interactions and Diagnostics
- Hydrology and Drought Analysis
- GNSS positioning and interference
- Financial Risk and Volatility Modeling
- Atmospheric Ozone and Climate
Laboratory for Atmospheric and Space Physics
2015-2025
University of Colorado Boulder
2015-2025
University of Colorado System
2016-2025
Planetary Science Institute
2023-2024
University of California, Los Angeles
2023-2024
University of California, Berkeley
2023-2024
Rice University
2011-2014
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....
Abstract We present observations by the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission of a substantial plume‐like distribution escaping ions from Martian atmosphere, organized upstream solar wind convection electric field. From case study MAVEN particle‐and‐field data during one spacecraft orbit, we identified three planetary ion populations: plume fluxes mainly along field over north pole region Mars‐Sun‐Electric (MSE) coordinate system, antisunward in tail region, much weaker...
Abstract We present the results of an initial effort to statistically map fluxes planetary ions on a closed surface around Mars. Choosing spherical shell ~1000 km above planet, we both outgoing and incoming ion (with energies >25 eV) over 4 month period. The show net escape behind Mars strong escaping from northern hemisphere with respect solar wind convection electric field. Planetary also travel toward return are particularly in southern field hemisphere. obtain lower bound estimate for...
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 study the Mars Atmosphere and Volatile Evolution spacecraft observations of Martian planetary ion escape during two time periods: 11 November 2014 to 19 March 2015 4 June 24 October 2015, with focus on understanding seasonal variability in response solar extreme ultraviolet (EUV) flux. organize >6 eV O + data by upstream electric field direction estimate rates through plume tail. To investigate dependence EUV flux, we constrain wind dynamic pressure interplanetary magnetic...
Atmospheric ion escape plays a crucial role in the evolution of planetary climate and habitability. While Mars has been focus extensive in-situ spacecraft observations, our understanding at constrained by single-point measurements, which fail to distinguish spatial temporal variability. Observations from NASA's Atmosphere Volatile EvolutioN (MAVEN) mission China's Tianwen-1 provide complementary observations Martian space environment unique opportunity study variability escape. Here, we...
There have been three Cassini encounters with the south‐pole eruptive plume of Enceladus for which Plasma Spectrometer (CAPS) had viewing in spacecraft ram direction. In each case, CAPS detected a cold dense population heavy charged particles having mass‐to‐charge ( m / q ) ratios up to maximum detectable by (∼10 4 amu/ e ). These are interpreted as singly nanometer‐sized water‐ice grains. Although they both negative and positive net charges, former greatly outnumber latter, at least range...
Abstract We present results from a global Mars time‐dependent MHD simulation under constant solar wind and radiation impact considering inherent magnetic field variations due to continuous planetary rotation. calculate the 3‐D shapes locations of bow shock (BS) induced magnetospheric boundary (IMB) then examine their dynamic changes with time. develop physics‐based, empirical algorithm effectively summarize multidimensional crustal distribution. It is found that by organizing model using...
Abstract We present a time‐dependent MHD study of the controlling effects Mars crustal field on atmospheric escape. calculate globally integrated planetary ion loss rates under quiet solar conditions considering continuous rotation anomalies with planet. It is found that rotating plays an important role in Significant time variation ∼20% and ∼50% observed during entire period for O + , respectively. The control exerted mainly through two processes. First, magnetic pressure over subsolar...
Abstract The Mars Atmosphere and Volatile EvolutioN mission (MAVEN), launched on 18 November 2013, is now in its primary science phase, orbiting with a 4.5 h period. In this study, we use time‐dependent MHD model to interpret plasma observations made by MAVEN particle field instruments. Detailed comparisons between the relevant from are presented for an entire rotation under relatively quiet solar wind conditions. Through comparison along orbits, find that multispecies single‐fluid able...
Abstract We study the solar wind interaction with Martian upper atmosphere during 8 March 2015 interplanetary coronal mass ejection (ICME) by using a global multifluid MHD model. Comparison of simulation results observations from Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft shows good agreement. The total ion escape rate is increased an order magnitude, 2.05 × 10 24 s −1 (pre‐ICME phase) to 2.25 25 (ICME sheath phase), this time period. Two major channels are illustrated:...
Abstract We simulate and compare three phases of the Mars‐solar wind interaction with 8 March interplanetary coronal mass ejection (ICME) event using Mars Atmosphere Volatile EvolutioN (MAVEN) mission observations in order to derive heavy ion precipitation escape rates. The MAVEN provide initial conditions for steady state MHD model cases, which reproduce observed features solar density, velocity, magnetic field seen along orbit. Applying results a kinetic test particle model, we global maps...
Abstract The magnetic field draping pattern in the magnetosheath of Mars is interest for what it tells us about both solar wind interaction with obstacle and use measured there as a proxy upstream interplanetary (IMF) clock angle. We apply time‐dependent, global magnetohydrodynamic model toward quantifying spatial temporal variations direction on Martian dayside above 500‐km altitude. plasma are self‐consistently solved over one rotation period, dynamics morphology considered result crustal...
Abstract Mars regional and global dust storms are able to impact the lower/upper atmospheres through aerosol radiative heating cooling atmospheric circulation. Here we present first attempt globally investigate how transfers from neutral upper atmosphere ionosphere induced magnetosphere above 100‐km altitude. This is achieved by running a multifluid magnetohydrodynamic model under nondusty dusty conditions for 2017 late‐winter storm 1971–1972 storm. Our results show that dayside main...
[1] The Cassini E3, E5, and E7 encounters with Enceladus probed the south polar plumes, where Ion Neutral Mass Spectrometer (INMS) measured neutral H2O molecular densities up to ∼109 cm−3. We have constructed a physical model for expected water density in based on supersonic radial outflow from one or more of surface vents. apply this possible sources vapor associated multiple jets observed visible dust plumes. Our predictions fit well INMS measurements along trajectories. is optimized by...
Abstract We examine the newly discovered phenomena of sinuous aurora on nightside Mars, using images 130.4 and 135.6 nm oxygen emission measured by Emirates Mars Mission EMUS ultraviolet spectrograph, upstream measurements from MAVEN Express spacecraft. They are detected in ∼3% observations, totaling 73 clear detections. These emissions narrow, elongated (1,000–6,000 km), cross Mars' UV terminator, oriented generally toward anti‐solar point, clustering into north, south, east, west‐oriented...
Abstract Ice grains in the Enceladus plume have been observed by several Cassini instruments during many encounters. In this paper we study ice ranging from less than one nanometer to micrometers size based on multiple instrument observations. We analyzed nanograin data E17 and E18 Plasma Spectrometer (CAPS) energy spectra using approach of Hill et al. (2012) studied charging E3–E6 Radio Wave (RPWS)‐Langmuir Probe (LP) presented Morooka (2011). To bridge gap between CAPS observations Cosmic...
Abstract The canonical picture of the magnetotail unmagnetized planets consists draped interplanetary magnetic fields (IMFs) forming opposite‐directed lobes, separated by current sheet. DiBraccio et al. (2018, https://doi.org/10.1029/2018GL077251 ) showed that Mars's has a twist departing from this picture. Magnetohydrodynamic (MHD) results suggest asymmetry in how open field lines connected to planet populate tail causes apparent twist. To validate interpretation, we compare topology...
Abstract The solar wind interaction with Mars controls the transfer of energy and momentum from into magnetosphere, ionosphere atmosphere, driving structure, dynamics within each. This is highly dependent on upstream Interplanetary Magnetic Field (IMF) orientation. We use in‐situ plasma measurements made by Atmosphere Volatile EvolutioN (MAVEN) mission to identify several prominent features that arise when IMF aligned approximately parallel or antiparallel flow (conditions known as “radial...
Leveraging the wide area coverage of COSMOS-Web survey, we quantify abundance different morphological types from $z\sim 7$ with unprecedented statistics and establish robust constraints on epoch emergence Hubble sequence. We measure global (spheroids, disk-dominated, bulge-dominated, peculiar) resolved (stellar bars) morphologies for about 400,000 galaxies down to F150W=27 using deep learning, representing a two-orders-of-magnitude increase over previous studies. then provide reference...
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...