Possible Evolution of Minifilament-Eruption-Produced Solar Coronal Jets, Jetlets, and Spicules, into Magnetic-Twist-Wave “Switchbacks” Observed by the Parker Solar Probe (PSP)

Alphonse C Sterling,Navdeep K Panesar,Tanmoy Samanta,Ronald L Moore

doi:10.1088/1742-6596/1620/1/012020

Abstract

Many solar coronal jets result from erupting miniature-filament (“minifilament”) magnetic flux ropes that reconnect with encountered surrounding far-reaching field. Many of those minifilament flux ropes are apparently built and triggered to erupt by magnetic flux cancelation. If that cancelation (or some other process) results in the flux rope’s field having twist, then the reconnection with the far-reaching field transfers much of that twist to that reconnected far-reaching field. In cases where that surrounding field is open, the twist can propagate to far distances from the Sun as a magnetic-twist Alfvénic pulse. We argue that such pulses from jets could be the kinked-magnetic-field structures known as “switchbacks,” detected in the solar wind during perihelion passages of the Parker Solar Probe (PSP). For typical coronal-jet-generated Alfvénic pulses, we expect that the switchbacks would flow past PSP with a duration of several tens of minutes; larger coronal jets might produce switchbacks with passage durations ∼1hr. Smaller-scale jet-like features on the Sun known as “jetlets” may be small-scale versions of coronal jets, produced in a similar manner as the coronal jets. We estimate that switchbacks from jetlets would flow past PSP with a duration of a few minutes. Chromospheric spicules are jet-like features that are even smaller than jetlets. If some portion of their population are indeed very-small-scale versions of coronal jets, then we speculate that the same processes could result in switchbacks that pass PSP with durations ranging from about ∼2 min down to tens of seconds.

Highlights

Solar coronal jets are transient features in the Sun’s outer atmosphere, the corona, that were first studied in detail using observations from the X-ray telescope on the Yohkoh satellite ([1, 2]), which was launched in 1991
There is excellent evidence that many quiet Sun and coronal hole jets are made by minifilament eruptions
Active region jets develop and form the same way, but the process can be complicated by the more-complex and rapidly evolving magnetic environment of active regions compared to quieter solar regions

Summary

Introduction

Solar coronal jets are transient features in the Sun’s outer atmosphere, the corona, that were first studied in detail using observations from the X-ray telescope on the Yohkoh satellite ([1, 2]), which was launched in 1991. Under the assumption that a minifilament flux rope that contains twist erupts to produce a jet on reconnected coronal field that extends out into the heliosphere, we can expect that much of the twist of the minifilament field is transferred onto the open field This twist may continue to propagate outward, driving a density enhancement, and appearing as a white-light jet and a density enhancement in interplanetary space. Following [14], taking a coronal Alfven speed of 1000 km s−1 and a typical jet lifetime of 10 min, we can expect the time for the minifilament flux rope to transfer its twist to the open coronal field to be ∼600 s, so that the length of the Alfven twist-wave pulse in the corona would be ∼600,000 km. If there were negligible contraction of the pulse between the corona and PSP we would expect the time for the passage to be about 25 min; with contraction, it is less than this

A Possible Source for Shorter-Duration Switchbacks

Discussion and Conclusions