A5077502826- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Solar Radiation and Photovoltaics
- Earthquake Detection and Analysis
- Magnetic confinement fusion research
- Planetary Science and Exploration
- Gamma-ray bursts and supernovae
- Tropical and Extratropical Cyclones Research
- Fluid Dynamics and Turbulent Flows
- Distributed and Parallel Computing Systems
- Spacecraft Design and Technology
- Silicon and Solar Cell Technologies
- Economic Growth and Productivity
- Rocket and propulsion systems research
- Nuclear reactor physics and engineering
- Nanofluid Flow and Heat Transfer
- Astrophysics and Cosmic Phenomena
- solar cell performance optimization
- Gender, Labor, and Family Dynamics
- Computational Physics and Python Applications
- Currency Recognition and Detection
Heliophysics
2022-2024
Goddard Space Flight Center
2022-2024
Heliophysics Science Division
2022-2023
National Aeronautics and Space Administration
2023
Princeton University
2023
University of Arizona
2023
University of California, Berkeley
2020-2021
University of California System
2021
University of Iowa
2018
Abstract Launched on 12 Aug. 2018, NASA’s Parker Solar Probe had completed 13 of its scheduled 24 orbits around the Sun by Nov. 2022. The mission’s primary science goal is to determine structure and dynamics Sun’s coronal magnetic field, understand how solar corona wind are heated accelerated, what processes accelerate energetic particles. returned a treasure trove data that far exceeded quality, significance, quantity expectations, leading significant number discoveries reported in nearly...
Abstract The Solar Probe ANalyzer for Ions (SPAN-I) onboard NASA’s Parker spacecraft is an electrostatic analyzer with time-of-flight capabilities that measures the ion composition and three-dimensional distribution function of thermal corona solar-wind plasma. SPAN-I energy per charge ions in solar wind from 2 eV to 30 keV a field view 247.°5 × 120° while simultaneously separating H + He ++ develop 3D velocity functions individual species. These observations, combined reduced measured by...
After leaving the Sun's corona, solar wind continues to accelerate and cools, but more slowly than expected for a freely expanding adiabatic gas. We use in situ measurements from Parker Solar Probe Orbiter spacecrafts investigate stream of as it traverses inner heliosphere. The observations show heating acceleration plasma between outer edge corona near orbit Venus, connection presence large amplitude Alfv\'en waves. waves are perturbations interplanetary magnetic field that transport...
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....
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...
Abstract During the thirteenth encounter of Parker Solar Probe (PSP) mission, spacecraft traveled through a topologically complex interplanetary coronal mass ejection (ICME) beginning on 2022 September 5. PSP traversed flank and wake ICME while observing event for nearly two days. The ANalyzer FIELDS instruments collected in situ measurements plasma particles magnetic field at ∼13.3 R S from Sun. We observe classical signatures, such as fast-forward shock, bidirectional electrons, low proton...
Drawing connections between heliospheric spacecraft and solar wind sources is a vital step in understanding the evolution of corona into contextualizing \textit{in situ} timeseries. Furthermore, making advanced predictions this linkage for ongoing missions, such as Parker Solar Probe (PSP), necessary achieving useful coordinated remote observations maximizing scientific return. The general procedure estimating connectivity straightforward (i.e. magnetic field line tracing coronal model) but...
Solar wind ions exhibit distinct kinetic non-thermal features such as preferential heating and acceleration of alpha particles compared to protons. On the other hand, Coulomb collisions in solar act eliminate these gradually lead thermal equilibrium. Previous observations at 1 au have revealed that even though local plasma are rare, cumulative effect during a transit time particle can be important terms thermalizing populations reducing ion features. Here, we analyze Parker Probe study...
Abstract Ion-scale wave events or storms in the solar wind are characterized by enhancements magnetic field fluctuations as well coherent polarization signatures at around local ion cyclotron frequencies. In this paper, we study detail one such event from Parker Solar Probe's (PSP) fourth encounter, consisting of an initial period left-handed (LH) abruptly transitioning to a strong right-handed (RH) polarization, accompanied clear core beam structure both alpha and proton velocity...
Abstract Upstream of quasi-parallel bow shocks, reflected ions generate ion–ion instabilities. The resulting magnetic fluctuations can advect through the shock and interact with planetary magnetospheres. amplitude depends on strength shock, quantified by Alfvén Mach number ( M A ), which is ratio solar wind velocity to local velocity. With increasing heliocentric distance, generally increases, such that Mercury typically experiences a lower ∼ 5 compared Earth 8), Mars slightly higher 9....
Abstract In the corona, plasma is accelerated to hundreds of kilometers per second and heated temperatures times hotter than Sun's surface before it escapes form solar wind. Decades space-based experiments have shown that energization process does not stop after escapes. Instead, wind continues accelerate, cools far more slowly a freely expanding adiabatic gas. Recent work suggests fast requires additional momentum beyond what can be provided by observed thermal pressure gradients alone,...
Electrostatic analyzers of different designs have been used since the earliest days space age, beginning with very solar wind measurements made by Mariner 2 en route to Venus in 1962. The Parker Solar Probe (PSP) mission, NASA's first dedicated mission study innermost reaches heliosphere, makes its thermal plasma using a suite instruments called Wind Electrons, Alphas, and Protons (SWEAP) investigation. SWEAP's electron Analyzer (SPAN-E) are pair top-hat electrostatic on PSP that capable...
The dissipation of magnetized turbulence is an important paradigm for describing heating and energy transfer in astrophysical environments such as the solar corona wind; however, specific collisionless processes behind remain relatively unconstrained by measurements. Remote sensing observations have suggested presence strong temperature anisotropy consistent with cyclotron resonant heating. In wind, situ magnetic field measurements reveal waves, while measured ion velocity distribution...
Abstract The SWEAP instrument suite on Parker Solar Probe (PSP) has detected numerous proton beams associated with coherent, circularly polarized, ion-scale waves observed by PSP’s FIELDS suite. Measurements during PSP Encounters 4−8 revealed pronounced complex shapes in the velocity distribution functions (VDFs), which tip of beam undergoes strong perpendicular diffusion, resulting VDF level contours that resemble a “hammerhead.” We refer to these beams, their attendant “hammerhead”...
A variety of energy sources, ranging from dynamic processes like magnetic reconnection and waves to quasi-steady terms the plasma pressure, may contribute acceleration solar wind. We utilize a combination charged particle field observations Parker Solar Probe (PSP) attempt quantify steady-state contribution proton electric potential, wave wind observed by PSP between 13.3 ~100 radii (RS). The pressure provides natural kinematic driver outflow. ambipolar potential acts couple electron...
The hot and diffuse nature of the Sun's extended atmosphere allows it to persist in non-equilibrium states for long enough that wave-particle instabilities can arise modify evolution expanding solar wind. Determining which arise, how significant a role they play governing dynamics wind, has been decades-long process involving situ observations at variety radial distances. With new measurements from Parker Solar Probe (PSP), we study what wave modes are driven near Sun, calculate predicted...
We make use of the Parker Solar Probe (PSP) data to explore nature solar wind turbulence focusing on Alfv\'enic character and power spectra fluctuations their dependence distance context (i.e. large scale properties), aiming understand role that different effects such as source properties, expansion, stream interaction might play in determining turbulent state. carry out a statistical survey from first five orbits PSP with focus how fluctuation properties at large, MHD scales, vary streams...
We report observations of reconnection exhausts in the Heliospheric Current Sheet (HCS) during Parker Solar Probe Encounters 08 and 07, at 16 Rs 20 , respectively. current sheet accelerated protons to almost twice solar wind speed increased proton core energy by a factor ∼3, due Alfvén being comparable flow these near-Sun distances. Furthermore, were energized super-thermal energies. During E08, found have leaked out exhaust along separatrix field lines, appearing as field-aligned energetic...
Abstract Collisionless shock waves, ubiquitous in the Universe, are crucial for particle acceleration various astrophysical systems. Currently, heliosphere is only natural environment available their situ study. In this work, we showcase collective of electrons and ions by one fastest shocks ever recorded, observed pioneering Parker Solar Probe at 34.5 million km from Sun. Our analysis unprecedented, near-parallel shows electron up to 6 MeV amidst intense multiscale electromagnetic wave...
Abstract Parker Solar Probe (PSP) has shown that the solar wind in inner heliosphere is characterized by quasi omnipresence of magnetic switchbacks (“switchback” hereinafter), local backward bends field lines. Switchbacks also tend to come patches, with a large-scale modulation appears have spatial scale size comparable supergranulation on Sun. Here we inspect data from first 10 encounters PSP focusing different time intervals when clear switchback patches were observed PSP. We show...
Switchbacks are rapid magnetic field reversals that last from seconds to hours. Current Parker Solar Probe (PSP) observations pose many open questions in regard the nature of switchbacks. For example, they stable as propagate through inner heliosphere, and how formed? In this work, we aim investigate structure origin order study stability switchbacks, suppose small-scale current sheets therein generated by braiding, should work stabilize With more than one thousand switchbacks identified...
Abstract During Parker Solar Probe (Parker) Encounter 15 (E15), we observe an 18 hr period of near-subsonic ( M S ∼ 1) and sub-Alfvénic (SA), A ⋘ 1, slow-speed solar wind from 22 to 15.6 R ⊙ . As the most extreme SA interval measured date skirting sonic point, it is deepest has probed into formation acceleration region in corona. The stream also by Wind Magnetosonic Multiscale mission near 1 au at times consistent with ballistic propagation this slow stream. We investigate source,...
First results from the Parker Solar Probe (PSP) mission have revealed ubiquitous coherent ion-scale waves in inner heliosphere, which are signatures of kinetic wave-particle interactions and fluid-scale instabilities. However, initial studies circularly polarized observed by PSP only thoroughly analyzed magnetic field signatures, precluding a determination solar-wind frame propagation direction intrinsic wave-polarization. A comprehensive wave-properties requires measurements both electric...
In the corona, plasma is accelerated to hundreds of kilometers per second, and heated temperatures times hotter than Sun's surface, before it escapes form solar wind. Decades space-based experiments have shown that energization process does not stop after escapes. Instead, wind continues accelerate cools far more slowly a freely-expanding adiabatic gas. Recent work suggests fast requires additional momentum beyond what can be provided by observed thermal pressure gradients alone whereas...
In December of 2024, the Parker Solar Probe performed its first encounter in what is planned to be final orbital configuration. At this distance from Sun, it expected that will spend a large fraction each perihelion pass deep below Alfvén critical point. It also that, during period peak solar activity, mission have best opportunities measure low-latitude coronal hole streams and interplanetary mass ejections their earliest phases evolution. presentation, we preview observations Wind...