A5072613902- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Stellar, planetary, and galactic studies
- Planetary Science and Exploration
- Geophysics and Gravity Measurements
- Solar Radiation and Photovoltaics
- Gamma-ray bursts and supernovae
- Seismic Waves and Analysis
- Radio Astronomy Observations and Technology
- Ocean Waves and Remote Sensing
- Spacecraft Design and Technology
- Magnetic confinement fusion research
- Space Satellite Systems and Control
- Photovoltaic System Optimization Techniques
- Astrophysics and Cosmic Phenomena
- GNSS positioning and interference
- Atmospheric aerosols and clouds
- Spacecraft and Cryogenic Technologies
- Space exploration and regulation
- Atmospheric Ozone and Climate
- Atomic and Subatomic Physics Research
- Aeolian processes and effects
University of Minnesota
2016-2025
University of Minnesota System
1998-2023
Goddard Space Flight Center
1995-2023
Urban College of Boston
2023
Laboratory for Atmospheric and Space Physics
2023
University of Glasgow
2023
1366 Technologies (United States)
2021
University of Michigan–Ann Arbor
2021
Twin Cities Orthopedics
2009-2020
University of California, Berkeley
2020
The Electric Fields and Waves (EFW) Instruments on the two Radiation Belt Storm Probe (RBSP) spacecraft (recently renamed Van Allen Probes) are designed to measure three dimensional quasi-static low frequency electric fields waves associated with major mechanisms responsible for acceleration of energetic charged particles in inner magnetosphere Earth. For this measurement, instrument uses pairs spherical double probe sensors at ends orthogonal centripetally deployed booms spin plane...
The first two orbits of the Parker Solar Probe (PSP) spacecraft have enabled in situ measurements solar wind down to a heliocentric distance 0.17 au (or 36 Rs). Here, we present an analysis this data study turbulence at and its evolution out 1 au. While many features remain similar, key differences include: increased energy levels by more than order magnitude, magnetic field spectral index -3/2 matching that velocity both Elsasser fields, lower compressibility consistent with smaller...
One of the most striking observations made by Parker Solar Probe during its first solar encounter is omnipresence rapid polarity reversals in a magnetic field that otherwise mostly radial. These so-called switchbacks strongly affect dynamics field. We concentrate here on their macroscopic properties. First, we find these structures are self-similar, and have neither characteristic magnitude, nor duration. Their waiting time statistics shows evidence for aggregation. The associated long...
We present observations of intense, bipolar, electrostatic structures in the transition region terrestrial bow shock from Wind spacecraft. The electric field signatures are on order a tenth millisecond duration and greater than 100 mV/m amplitude. measured is generally larger smaller dipole antenna, indicating small spatial size. compare potential two antennas with model antenna response to Gaussian profile. This result agrees scale determined by convection gives characteristic size 2–7 λ d...
During a passage through the Earth's dawn‐side outer radiation belt, whistler‐mode waves with amplitudes up to more than ∼240 mV/m were observed by STEREO S/WAVES instrument. These are an order of magnitude larger previously for whistlers in belt. Although peak frequency is similar whistler chorus, there distinct differences from addition amplitudes, including lack drift and oblique propagation large longitudinal electric field component. Simulations show that these amplitude can energize...
We report data from the Cassini radio and plasma wave instrument during approach first orbit at Saturn. During approach, emissions Saturn showed that rotation period is now 10 hours 45 minutes +/- 36 seconds, about 6 longer than measured by Voyager in 1980 to 1981. In addition, many intense impulsive signals were detected lightning orbit. Some of these have been linked storm systems observed imaging instrument. Within magnetosphere, whistler-mode auroral hiss near rings, suggesting a strong...
The STEREO/WAVES instrument has detected a very large number of intense voltage pulses. We suggest that these events are produced by impact ionisation nanoparticles striking the spacecraft at velocity order magnitude solar wind speed. Nanoparticles, which half-way between micron-sized dust and atomic ions, have such charge-to-mass ratio electric field induced magnetic accelerates them efficiently. Since impacts increases fast with speed, produce signals as high do much larger grains smaller...
Heat transport in the solar corona and wind is still a major unsolved astrophysical problem. Because of key role played by electrons, electron density temperature(s) are important prerequisites for understanding these plasmas. We present such situ measurements along two first encounters Parker Solar Probe (PSP), between 0.5 0.17 AU from Sun, revealing different states emerging near activity minimum. These preliminary results obtained simplified analysis plasma quasi-thermal noise (QTN)...
The Solar Wind Electrons Alphas and Protons experiment on the Parker Probe (PSP) mission measures three-dimensional electron velocity distribution function. We derive parameters of core, halo, strahl populations utilizing a combination fitting to model distributions numerical integration for $\sim 100,000$ measured near Sun first two PSP orbits, which reached heliocentric distances as small 0.17$ AU. As expected, core density temperature increase with decreasing distance, while ratio thermal...
Abstract Measurements of the near-Sun solar wind by Parker Solar Probe have revealed presence large numbers discrete Alfvénic impulses with an anti-sunward sense propagation. These are similar to those previously observed near 1 au, in high speed streams over Sun’s poles and at 60 radii. At 35 radii, however, they typically shorter sharper than seen elsewhere. In addition, these spikes occur “patches” there also clear periods within same stream when do not occur; timescale patches might be...
The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is described in this paper. This designed to measure in-situ magnetic electric fields waves from continuous a few hundreds of kHz. RPW will also observe solar radio emissions up 16 MHz. primary importance science requirements since it essential answer three four overarching objectives. In addition exchange on-board data with other instruments order process algorithms for interplanetary shocks type III langmuir detections.
We analyze dust impacts recorded by the S/WAVES radio instrument onboard two STEREO spacecraft near 1 A.U. during period 2007–2010. The impact of a particle on produces plasma cloud whose associated electric field can be detected on‐board antennas. For this study we use potential time series waveform sampler instrument. high resolution and long sampling times measurement enable us to deduce considerably more information than in previous studies based dynamic power spectra provided same or...
Abstract Parker Solar Probe ( PSP ) observations during its first encounter at 35.7 R ⊙ have shown the presence of magnetic field lines that are strongly perturbed to point they produce local inversions radial field, known as switchbacks. Their counterparts in solar wind velocity enhancements speed, or jets, displaying (in all components) velocity–magnetic correlation typical large amplitude Alfvén waves propagating away from Sun. Switchbacks and jets previously been observed over a wide...
The Radio Frequency Spectrometer (RFS) is a two‐channel digital receiver and spectrometer, which will make remote sensing observations of radio waves in situ measurements electrostatic electromagnetic fluctuations the solar wind. A part FIELDS suite for Solar Probe Plus (SPP), RFS optimized inner heliosphere, where bursts are more intense plasma frequency higher compared to previous at distances 1 AU or greater. inputs four electric antennas mounted near front SPP spacecraft single axis...
Abstract Switchbacks (rotations of the magnetic field) are observed on Parker Solar Probe . Their evolution, content, and plasma effects studied in this paper. The solar wind does not receive a net acceleration from switchbacks that it encountered upstream observation point. typical switchback rotation angle increased with radial distance. Significant Poynting fluxes existed inside, but outside, switchbacks, dependence flux amplitude location is explained quantitatively as being proportional...
Understanding the physical processes in solar wind and corona which actively contribute to heating, acceleration, dissipation is a primary objective of NASA's Parker Solar Probe (PSP) mission. Observations coherent electromagnetic waves at ion scales suggests that linear cyclotron resonance non-linear are dynamically relevant inner heliosphere. A wavelet-based statistical study first perihelion encounter PSP demonstrates presence transverse resonant observed 30-50\% radial field intervals....
Magnetic reconnection in current sheets converts magnetic energy into particle energy. The process may play an important role the acceleration and heating of solar wind close to Sun. Observations from Parker Solar Probe provide a new opportunity study this problem, as it measures at unprecedented distances During 1st orbit, PSP encountered large number through perihelion 35.7 radii. We performed comprehensive survey these found evidence for 21 exhausts. These exhausts were observed...
Abstract During Parker Solar Probe ’s first orbit, the solar wind plasma was observed in situ closer than ever before, perihelion on 2018 November 6 revealing a flow that is constantly permeated by large-amplitude Alfvénic fluctuations. These include radial magnetic field reversals, or switchbacks, seem to be persistent feature of young wind. The measurements also reveal very strong, unexpected, azimuthal velocity component. In this work, we numerically model corona during encounter, solving...
Abstract Parker Solar Probe (PSP), NASA’s latest and closest mission to the Sun, is on a journey investigate fundamental enigmas of inner heliosphere. This paper reports initial observations made by Analyzer for Ions (SPAN-I), one instruments in Wind Electrons Alphas Protons instrument suite. We address presence secondary proton beams concert with ion-scale waves observed FIELDS, electromagnetic fields show two events from PSP’s second orbit that demonstrate signatures consistent...
We consider 2D joint distributions of normalized residual energy, σr(s, t), and cross helicity, σc(s, during one day Parker Solar Probe's (PSP's) first encounter as a function wavelet scale s. The broad features the are similar to previous observations made by Helios in slow solar wind, namely well-correlated fairly Alfvénic except for population with negative helicity that is seen at shorter scales. show this due presence magnetic switchbacks, or brief periods where field polarity reverses....