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

Context.
Aims: 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.
Methods: We extended our previous magnetic helicity-based technique of identifying magnetic flux rope structures. The method was improved upon to incorporate the azimuthal flow, which becomes larger as the spacecraft approaches the Sun.
Results: A total of 21 and 34 magnetic flux ropes are identified during the third (21-day period) and fourth (17-day 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.