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Parker Solar Probe: Four Years of Discoveries at Solar Cycle Minimum
McComas, D. J.; Bale, S. D.; Matteini, L. +55 more
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 the structure and dynamics of the Sun's coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what processes accelerate …
The Radial Variation of the Solar Wind Turbulence Spectra near the Kinetic Break Scale from Parker Solar Probe Measurements
Bale, S. D.; Kontar, E. P.; Engelbrecht, N. E. +7 more
In this study we examine the radial dependence of the inertial and dissipation range indices, as well as the spectral break separating the inertial and dissipation range in power density spectra of interplanetary magnetic field fluctuations using Parker Solar Probe data from the fifth solar encounter between ~0.1 and ~0.7 au. The derived break wav…
Extreme Solar Events: Setting up a Paradigm
Notsu, Yuta; Maehara, Hiroyuki; Dalla, Silvia +17 more
The Sun is magnetically active and often produces eruptive events on different energetic and temporal scales. Until recently, the upper limit of such events was unknown and believed to be roughly represented by direct instrumental observations. However, two types of extreme events were discovered recently: extreme solar energetic particle events o…
Future Exploration of the Outer Heliosphere and Very Local Interstellar Medium by Interstellar Probe
Wurz, P.; Krimigis, S. M.; Kurth, W. S. +40 more
A detailed overview of the knowledge gaps in our understanding of the heliospheric interaction with the largely unexplored Very Local Interstellar Medium (VLISM) are provided along with predictions of with the scientific discoveries that await. The new measurements required to make progress in this expanding frontier of space physics are discussed…
Modeling a Coronal Mass Ejection from an Extended Filament Channel. II. Interplanetary Propagation to 1 au
Scolini, Camilla; Lynch, Benjamin J.; Palmerio, Erika +5 more
We present observations and modeling results of the propagation and impact at Earth of a high-latitude, extended filament channel eruption that commenced on 2015 July 9. The coronal mass ejection (CME) that resulted from the filament eruption was associated with a moderate disturbance at Earth. This event could be classified as a so-called "proble…
Statistical Analysis of Interplanetary Shocks from Mercury to Jupiter
Janvier, Miho; Nieves-Chinchilla, Teresa; Démoulin, Pascal +3 more
In situ observations of interplanetary (IP) coronal mass ejections (ICMEs) and IP shocks are important to study as they are the main components of solar activity. Hundreds of IP shocks have been detected by various space missions at different times and heliocentric distances. Some of these are followed by clearly identified drivers, while some oth…
Estimates of Proton and Electron Heating Rates Extended to the Near-Sun Environment
McComas, D. J.; Bale, S. D.; Cranmer, S. R. +11 more
A central problem of space plasma physics is how protons and electrons are heated in a turbulent, magnetized plasma. The differential heating of charged species due to dissipation of turbulent fluctuations plays a key role in solar wind evolution. Measurements from previous heliophysics missions have provided estimates of proton and electron heati…
Unfolding Drift Effects for Cosmic Rays over the Period of the Sun's Magnetic Field Reversal
Luo, Xi; Potgieter, M. S.; Aslam, O. P. M. +2 more
A well-established, comprehensive 3D numerical modulation model is applied to simulate galactic protons, electrons, and positrons from 2011 May to 2015 May, including the solar magnetic polarity reversal of Solar Cycle 24. The objective is to evaluate how simulations compare with corresponding Alpha Magnetic Spectrometer observations for 1.0-3.0 G…
The Polytropic Behavior of Solar Wind Protons as Observed by the Ulysses Spacecraft during Solar Minimum
Livadiotis, George; Nicolaou, Georgios; McComas, David J.
We analyze proton bulk parameters derived from Ulysses observations and investigate the polytropic behavior of solar wind protons over a wide range of heliocentric distances and latitudes. The large-scale variations of the proton density and temperature over heliocentric distance indicate that plasma protons are governed by subadiabatic processes …
On the General Correlation between 3D Solar Wind Speed and Density Model and Solar Proxies
Bzowski, M.; Tokumaru, M.; Porowski, C.
The solar wind (SW) is a supersonic outflow of plasma from the solar corona, with the latitudinal speed and density profiles varying with the solar activity. The SW protons charge exchange with the inflowing interstellar neutral atoms and create energetic neutral atoms (ENAs), which bring information on the physical state of the plasma within the …