Detection of small magnetic flux ropes from the third and fourth Parker Solar Probe encounters

TL;DR

This study identifies and analyzes small magnetic flux ropes in the solar wind close to the Sun using Parker Solar Probe data, extending previous detection methods to improve accuracy near the Sun.

Contribution

The paper introduces an improved flux rope detection technique that accounts for azimuthal flow, enabling more accurate identification of structures closer to the Sun.

Findings

21 flux ropes identified in the third orbit

34 flux ropes identified in the fourth orbit

Flux ropes show relation to streamer belt and current sheet

Abstract

We systematically search for magnetic flux rope structures in the solar wind to within the closest distance to the Sun of 0.13 AU, using data from the third and fourth orbits of the Parker Solar Probe. We extend our previous magnetic helicity based technique of identifying magnetic flux rope structures. The method is improved upon to incorporate the azimuthal flow, which becomes larger as the spacecraft approaches the Sun. A total of 21 and 34 magnetic flux ropes are identified during the third (21 days period) and fourth (17 days period) orbits of the Parker Solar Probe, respectively. We provide a statistical analysis of the identified structures, including their relation to the streamer belt and heliospheric current sheet crossing.