Searching for a Solar Source of Magnetic-Field Switchbacks in Parker Solar Probe's First Encounter

Area of Science:

• * Solar Physics
• * Heliophysics
• * Plasma Physics

Background:

• * Magnetic field reversals, termed switchbacks, are prevalent in the inner heliosphere.
• * Previously observed rarely near 1 AU, switchbacks are now recognized as dominant structures in the young solar wind below ~0.2 AU.
• * Parker Solar Probe (PSP) provides in situ measurements of these phenomena closer to the Sun than ever before.

Purpose of the Study:

• * To investigate the coronal origin of switchbacks observed by Parker Solar Probe.
• * To correlate in situ switchback signatures with remote observations of their coronal sources.
• * To understand the relationship between coronal structures and the outflowing solar wind.

Main Methods:

• * Analysis of Parker Solar Probe (PSP) in situ data during Encounter 1.
• * Correlation of switchback signatures with remote-sensing observations of a specific equatorial coronal hole.
• * Spatial analysis of the coronal region to determine optimal solar wind speed estimations.

Main Results:

• * Strong linear correlations found between coronal timescales and switchback characteristics in the solar wind.
• * Spatial analysis confirmed optimal solar wind speed estimations matching PSP observations.
• * Hemispherical structures in the corona showed strong correlations with radial proton velocity and solar wind mass flux.

Conclusions:

• * A significant subpopulation of solar wind switchbacks are likely seeded at their coronal footpoints.
• * These switchbacks propagate from the corona into interplanetary space.
• * The findings highlight the relevance of coronal processes in shaping the young solar wind.