Authors: Kyung-Eun Choi(SSL-UCB), Oleksiy Agapitov(SSL-UCB), Nina Bizien(CNRS-University of Orleans), Clara Froment(CNRS-University of Orleans), Thierry Dudok de Wit (CNRS-University of Orleans)

Switchbacks (SBs) are localized magnetic structures found in the solar wind that exhibit deviations in the magnetic field direction compared to the background solar wind magnetic field. Inside SBs, there is an alignment between perturbations in the magnetic field (dB) and the bulk solar wind velocity (dV), leading to abrupt increases in the radial bulk velocity within SBs. The mechanisms behind the formation of SBs and the factors influencing their characteristics, such as deflection angle, Alfvénicity, and plasma temperature, are still not fully elucidated. Enhancements in wave activity at the boundaries of SBs have been linked to surface waves. This study investigates the nature and parameters of SB boundaries, examining their stability and relationship with waves at these boundaries. Utilizing data from the Parker Solar Probe, we analyze the dynamics of SB boundary features and the associated wave activity as a function of heliocentric distance. Special focus is placed on the boundary structure and its stability concerning surface shear flow perturbations.