Search Publications
Cataloging Stream Interaction Regions at MAVEN: A Cross-comparative Study with STEREO-A
Allen, Robert C.; Lee, Christina O.; Halekas, Jasper S. +5 more
Stream interaction regions (SIRs) are long-lasting solar wind structures that result from stable fast solar wind interacting with preceding slow solar wind. These structures have been examined in depth throughout the heliosphere, particularly at 1 au; however, due to sparse observations, SIRs have not been characterized thoroughly at 1.5 au. Thank…
Ion Charge States from a Global Time-dependent Wave-turbulence-driven Model of the Solar Wind: Comparison with in Situ Measurements
Riley, Pete; Rivera, Yeimy J.; Lionello, Roberto
Solar wind charge-state measurements contain a wealth of knowledge related to the properties of the solar corona from where they originated. However, their interpretation has remained challenging because it convolves coronal temperature, density, and velocity along the particles' trajectory through the corona before they "freeze in" and are convec…
Fluctuations Driven by Multicomponent Pickup Ion Distributions in the Outer Heliosheath
Roytershteyn, Vadim; Mousavi, Ameneh; Fraternale, Federico +1 more
The stability of a realistic multicomponent pickup ion (PUI) velocity distribution derived from a global model of neutral atoms in the heliosphere, which treats hydrogen and helium atoms self-consistently and includes equations for electrons and helium ions, is investigated using linear instability analysis and hybrid simulations. Linear instabili…
Juno Observations of Langmuir Waves in Association with Interplanetary Shocks from ~1.3 to ~5.4 au
Cattell, C.; Elliott, S.; Hanson, E. L. M. +1 more
Langmuir waves are often observed upstream of planetary bow shocks and interplanetary (IP) shocks. Waveform capture (WFC) measurements, obtained during Juno's cruise phase, reveal the occurrence of Langmuir waves, as well as other wave modes, in association with IP shocks and IP coronal mass ejections (ICMEs) at distances from ∼1.3 to ∼5.4 au. Thi…
Constraining Solar Wind Transport Model Parameters Using Bayesian Analysis
Parashar, Tulasi N.; Oughton, Sean; Bishop, Mark A. +1 more
We apply nested-sampling Bayesian analysis to a model for the transport of magnetohydrodynamic-scale solar wind fluctuations. The dual objectives are to obtain improved constraints on parameters present in the turbulence transport model (TTM) and to support quantitative comparisons of the quality of distinct versions of the transport model. The TT…
Proposed Resolution to the Solar Open Magnetic Flux Problem
Antiochos, Spiro K.; Wallace, Samantha; Henney, Carl J. +2 more
The solar magnetic fields emerging from the photosphere into the chromosphere and corona are comprised of a combination of closed (field lines with both ends rooted at the Sun) and open (field lines with only one end at the Sun) fields. Since the early 2000s, the magnitude of total unsigned open magnetic flux estimated by coronal models has been i…
New Horizons Venetia Burney Student Dust Counter Observes Higher than Expected Fluxes Approaching 60 au
Singer, Kelsi N.; Stern, S. Alan; Verbiscer, Anne +8 more
The NASA New Horizons Venetia Burney Student Dust Counter (SDC) measures dust particle impacts along the spacecraft's flight path for grains with mass ≥10‑12 g, mapping out their spatial density distribution. We present the latest SDC dust density, size distribution, and flux measurements through 55 au and compare them to numerical mode…
Comparative Analysis of Type III Radio Bursts and Solar Flares: Spatial Localization and Correlation with Solar Flare Intensity
Maksimovic, Milan; Szabo, Adam; Bale, Stuart D. +8 more
We present a comprehensive study of type III radio bursts and their association with solar flares of magnitude M1.0 and larger, as observed by four widely separated spacecraft (Parker Solar Probe, Solar Orbiter, STEREO-A, and Wind). Our main focus is the introduction and validation of two methods for localizing radio bursts using the available mul…
Parallel Diffusion Coefficient of Energetic Charged Particles in the Inner Heliosphere from the Turbulent Magnetic Fields Measured by Parker Solar Probe
Klein, Kristopher G.; Chen, Xiaohang; Giacalone, Joe +1 more
Diffusion coefficients of energetic charged particles in turbulent magnetic fields are a fundamental aspect of diffusive transport theory but remain incompletely understood. In this work, we use quasi-linear theory to evaluate the spatial variation of the parallel diffusion coefficient κ ∥ from the measured magnetic turbulence power spe…
Radial Distribution of Electron Quasi-thermal Noise in the Outer Heliosphere
Chen, Ling; Li, Yi-Lun; Wu De, Jin
Voyager 1 and 2 are only the two spacecraft that have arrived and passed through the heliospheric boundaries. Based on the plasma data from the Voyager 2 spacecraft, the electron quasi-thermal noise (QTN) is investigated by using of the electron population model consisting of a core with Maxwellian distribution and a halo with kappa distribution. …