@article{Bizien:2023:1538-4357/acf99a,
author = {Bizien, N and Dudok, de Wit T and Froment, C and Velli, M and Case, AW and Bale, SD and Kasper, J and Whittlesey, P and MacDowall, R and Larson, D},
doi = {1538-4357/acf99a},
journal = {Astrophysical Journal},
title = {Are Switchback Boundaries Observed by Parker Solar Probe Closed?},
url = {http://dx.doi.org/10.3847/1538-4357/acf99a},
volume = {958},
year = {2023}
}

Download

TY  - JOUR
AB  - Switchbacks are sudden and large deflections in the magnetic field that Parker Solar Probe frequently observes in the inner heliosphere. Their ubiquitous occurrence has prompted numerous studies to determine their nature and origin. Our goal is to describe the boundary of these switchbacks using a series of events detected during the spacecraft’s first encounter with the Sun. Using FIELDS and SWEAP data, we investigate different methods for determining the boundary normal. The observed boundaries are arc-polarized structures with a rotation that is always contained in a plane. Classical minimum variance analysis gives misleading results and overestimates the number of rotational discontinuities. We propose a robust geometric method to identify the nature of these discontinuities, which involves determining whether or not the plane that contains them also includes the origin ( B = 0). Most boundaries appear to have the same characteristics as tangential discontinuities in the context of switchbacks, with little evidence for having rotational discontinuities. We find no effect of the size of the Parker spiral deviation. Furthermore, the thickness of the boundary is within MHD scales. We conclude that most of the switchback boundaries observed by Parker Solar Probe are likely to be closed, in contrast to previous studies. Our results suggest that their erosion may be much slower than expected.
AU  - Bizien,N
AU  - Dudok,de Wit T
AU  - Froment,C
AU  - Velli,M
AU  - Case,AW
AU  - Bale,SD
AU  - Kasper,J
AU  - Whittlesey,P
AU  - MacDowall,R
AU  - Larson,D
DO  - 1538-4357/acf99a
PY  - 2023///
SN  - 0004-637X
TI  - Are Switchback Boundaries Observed by Parker Solar Probe Closed?
T2  - Astrophysical Journal
UR  - http://dx.doi.org/10.3847/1538-4357/acf99a
VL  - 958
ER  - 

Download