A5034270295- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Planetary Science and Exploration
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Resource-Constrained Project Scheduling
- Geophysics and Gravity Measurements
- Space Satellite Systems and Control
- Scheduling and Optimization Algorithms
- Space Exploration and Technology
- Magnetic confinement fusion research
- Scientific Research and Discoveries
- Lightning and Electromagnetic Phenomena
- Geology and Paleoclimatology Research
- Magnetic and Electromagnetic Effects
- Operations Management Techniques
- Construction Project Management and Performance
- Space Science and Extraterrestrial Life
- GNSS positioning and interference
- VLSI and FPGA Design Techniques
- Gamma-ray bursts and supernovae
- Geophysics and Sensor Technology
- Atomic and Subatomic Physics Research
- Formal Methods in Verification
Planetary Science Institute
2016-2025
University of California, Los Angeles
2016-2025
Goddard Space Flight Center
2021
KTH Royal Institute of Technology
2021
Nanchang Institute of Technology
2015-2020
Earth and Space Research
2006-2020
Jiangxi Normal University
2020
Los Alamos National Laboratory
2010
Collisionless shock nonstationarity arising from microscale physics influences structure and particle acceleration mechanisms. Nonstationarity has been difficult to quantify due the small spatial temporal scales. We use closely spaced (subgyroscale), high-time-resolution measurements one rapid crossing of Earth's quasiperpendicular bow by Magnetospheric Multiscale (MMS) spacecraft compare competing processes. Using MMS's high-cadence kinetic plasma measurements, we show that exhibits in form ripples.
Abstract We report a rare regime of Earth's magnetosphere interaction with sub‐Alfvénic solar wind in which the windsock‐like transforms into one Alfvén wings. In magnetic cloud Coronal Mass Ejection (CME) on 24 April 2023, NASA's Magnetospheric Multiscale mission distinguishes following features: (a) unshocked and accelerated low‐beta CME plasma coming directly against dayside magnetosphere; (b) dynamical wing filaments representing new channels connection between foot points Sun's erupted...
Abstract Stream interaction regions (SIRs) are long-lasting solar wind structures that result from stable fast interacting with preceding slow wind. These have been examined in depth throughout the heliosphere, particularly at 1 au; however, due to sparse observations, SIRs not characterized thoroughly 1.5 au. Thanks Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, we a chance fill this observational gap. We implement situ data collected by MAVEN identify between 2014 November 2023...
Transverse, near-circularly polarized, parallel-propagating electromagnetic waves around the proton cyclotron frequency were found sporadically in solar wind throughout inner heliosphere. They could play an important role heating and accelerating wind. These low-frequency (LFWs) are intermittent but often occur prolonged bursts lasting over 10 minutes, named "LFW storms." Through a comprehensive survey of them from Solar Terrestrial Relations Observatory A using dynamic spectral wave...
Abstract Simulations and observations of collisionless shocks have shown that deviations the nominal local shock normal orientation, is, surface waves or ripples, are expected to propagate in ramp overshoot quasi‐perpendicular shocks. Here we identify signatures a ripple propagating during crossing Earth's marginally quasi‐parallel ( θ B n ∼45 ∘ ) bow on 27 November 2015 06:01:44 UTC by Magnetospheric Multiscale (MMS) mission determine ripple's properties using multispacecraft methods. Using...
This paper reports a new global multispecies single‐fluid MHD model that was recently developed for Venus. is similar to the numerical has been successfully applied Mars. Mass densities of proton and three important ionospheric ion species (O + , O 2 CO ) are self‐consistently calculated in by including related chemical reactions ion‐neutral collision processes. The simulation domain covers region from 100 km altitude above surface up 24 R V tail. An adaptive spherical grid structure...
Electron heating at Earth's quasiperpendicular bow shock has been surmised to be due the combined effects of a quasistatic electric potential and scattering through wave-particle interaction. Here we report observation electron distribution functions indicating new process occurring leading edge front. Incident solar wind electrons are accelerated parallel magnetic field toward downstream, reaching an electron-ion relative drift speed exceeding thermal speed. The bulk acceleration is...
The induced magnetosphere at Venus consists of regions near the planet and its wake for which magnetic pressure dominates all other contributions. Initial Express measurements indicate a well‐defined outer boundary, magnetopause, magnetosphere. This magnetopause acts as an obstacle to deflect solar wind. Across this field exhibits abrupt directional changes pronounced draping. In paper, we examine structure using measurements. We find that is discontinuity resembling either tangential or...
Flux transfer events observed at Mercury, Earth, and Jupiter are attributed to spatially temporally limited in which the magnetosheath magnetospheric magnetic field become interconnected flux is transported from dayside lobes of magnetotail. Examination Saturnian magnetopause local times 1000 1400 shows no evidence for this phenomenon. Nevertheless, we do find brief intervals during normal component across becomes significantly enhanced typically one ten minutes. Magnetosheath electrons...
Abstract Mirror mode waves are ubiquitous in the Earth's magnetosheath, particular behind quasi‐perpendicular shock. Embedded these nonlinear structures, intense lion roars often observed. Lion characterized by whistler wave packets at a frequency ∼100 Hz, which thought to be generated magnetic field minima. In this study, we make use of high time resolution instruments on board Magnetospheric MultiScale mission investigate and associated electron dynamics magnetosheath 22 January 2016. We...
We use simultaneous global observations of the mid‐latitude trough and plasmapause to experimentally prove a long‐standing conjecture magnetosphere‐ionosphere coupling‐ namely are on same field line. Global Ionospheric Maps (GIM), generated using ground based GPS receivers, used detect globally extended trough; while IMAGE EUV pictures estimate position. Observations during equinox solstices quiet disturbed periods analyzed. In addition, positions calculated simple empirical model. The two...
The fluxgate magnetometer on Venus Express samples the magnetic field near periapsis at 128 Hz. Bursts of plane‐polarized waves in vicinity 100 Hz are observed propagating small angles to field. is generally horizontal region around periapsis, located high northern latitudes. When remains within 15° during 2‐min pass, no such observed; but when there brief periods which local dips into atmosphere by more than 15°, bursts begin appear. Such radial excursions occur 25% time periapsis. seen...
Abstract We analyze two ion scale dipolarization fronts associated with field‐aligned currents detected by the Magnetospheric Multiscale mission during a large substorm on 10 August 2016. The first event corresponds to fast dawnward flow an antiparallel current and could be generated wake of previous earthward flow. It is intense lower hybrid drift waves at front propagating perpendicular phase speed close electric thermal velocity. second reversal: from southwward/dawnward...
Abstract Hot Flow Anomalies (HFAs) are transients observed at planetary bow shocks, formed by the shock interaction with a convected interplanetary current sheet. The primary interpretation relies on reflected ions channeled upstream along short duration of HFAs has made direct observations this process difficult. We employ high resolution measurements NASA's Magnetospheric Multiscale Mission to probe ion microphysics within HFA. data reveal smoothly varying internal density and pressure,...
Abstract The Magnetospheric Multiscale mission (MMS) consists of four identical spacecraft forming a closely separated (≤10 km) and nearly regular tetrahedron. This configuration enables the decoupling spatial temporal variations allows calculation gradients plasma electromagnetic field quantities. We make full use well cross‐calibrated MMS magnetometers fast instruments measurements to calculate both magnetic forces in flux transfer events (FTEs) evaluate relative contributions different...
Electrons in earth's magnetotail are energized significantly both the form of heating and acceleration to non-thermal energies. While magnetic reconnection is considered play an important role this energization, it still remains unclear how electrons energy partitioned between thermal components. Here, we show, based on situ observations by NASA's Magnetospheric Multiscale mission combined with multi-component spectral fitting methods, that average electron ε¯ (or equivalently temperature)...
Magnetic flux ropes are a fundamental component in both space and laboratory plasmas. We present Hall-MHD simulation exploring the interaction between two isolated magnetic under mesoscale solar wind conditions. The interface is resolved with resolution approaching kinetic scale, to reveal unprecedented details of this process. As we replicate previous findings that such interactions can lead formation new ropes, also find reconnection occurs multiple locations inside central current sheet,...
Abstract This study reports on a dayside magnetic reconnection event detected by the Magnetospheric Multiscale mission in presence of moderate guide field ( times reconnecting magnetosphere side) and assumed to be present whole region. The spacecraft traversed compressed magnetospheric separatrix region, observing cold ions with densities up 10 large magnetosheath density 150 . We provide detailed analysis current densities, generalized Ohm's law, energy conversion processes both fluid...
Substorms play an important role in the energization and transport of plasmas planetary magnetospheres, including shedding mass added by moons case Jupiter Saturn. Mass occurs through rapid reconnection near tail resulting dipolarization on magnetospheric side point plasmoid formation down tail. Observations these sudden events Saturn’s near‐tail region provide additional insight into this process. Saturnian substorms, at least occasion, have a phase leading to traveling compression region....
The escape of particles from planetary atmospheres, especially hydrogen, is an important key towards understanding the atmospheric composition and evolution over lifetime solar system. For unmagnetized planet such as Venus or Mars when neutral exosphere extends into flowing wind plasma, loss pick‐up ions upstream bow shock can play a significant role in process. Cyclotron waves hydrogen have been previously observed at other system bodies. At Venus, they were reported within magnetosheath,...
Abstract Within the solar wind throughout inner heliosphere, observations reveal presence of magnetic field enhancements accompanied by thin current sheets at varying distances from sun and across different longitudes latitudes. Two primary explanations have been proposed to elucidate these phenomena: Solar wind‐dust interaction interlacing flux ropes. In this study, we employ multi‐fluid Magnetohydrodynamics (MHD) Hall MHD models simulate hypotheses, respectively. Our findings indicate a...
Abstract Magnetic flux ropes are ubiquitous in various space environments, including the solar corona, interplanetary wind, and planetary magnetospheres. When these intertwine, magnetic reconnection may occur at interface, forming disentangled new ropes. Some of newly formed contain reversed helicity along their axes, diverging from traditional rope model. We introduce observations interpretations existing Hall Magnetohydrodynamics model results. first examine time‐varying local field...