Simulated Encounters of the Parker Solar Probe with a Coronal-hole Jet
|Author||Roberts, Merrill; Uritsky, Vadim; DeVore, Richard; Karpen, Judith;|
|Keywords||Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; Sun: activity; Sun: corona; Sun: heliosphere; Sun: magnetic fields|
Solar coronal jets are small, transient, collimated ejections most easily observed in coronal holes (CHs). The upcoming Parker Solar Probe (PSP) mission provides the first opportunity to encounter CH jets in situ near the Sun and examine their internal structure and dynamics. Using projected mission orbital parameters, we have simulated PSP encounters with a fully three-dimensional magnetohydrodynamic (MHD) model of a CH jet. We find that three internal jet regions, featuring different wave modes and levels of compressibility, have distinct identifying signatures detectable by PSP. The leading Alfv\ en wave front and its immediate wake are characterized by trans-Alfv\ enic plasma flows with mild density enhancements. This front exhibits characteristics of a fast switch-on MHD shock, whose arrival is signaled by the sudden onset of large-amplitude transverse velocity and magnetic-field oscillations highly correlated in space and time. The trailing portion is characterized by supersonic but sub-Alfv\ enic outflows of dense plasma with uncorrelated velocity and magnetic-field oscillations. This compressible region contains most of the jet\textquoterights mass. The volume between the immediate wake and dense jet, the remote wake, mixes and transitions the characteristics of the two other regions. In addition to probing each region separately, we also simulate a corotational PSP-jet encounter. In this scenario, the simulated spacecraft hovers over the jet-producing CH, as may occur during the mission\textquoterights corotational phases, sampling each jet region in turn. We estimate that PSP will encounter numerous CH jets over the lifetime of the mission.
|Year of Publication||2018|
|Journal||The Astrophysical Journal|
|Number of Pages||14|