Analysis on the Turbulent Properties of Current Sheets in the Solar Wind

Abstract The energy dissipation of solar wind turbulence, closely linked to solar wind heating, is a fundamental process in space physics. Previous research indicates that current sheets in the solar wind significantly influence both energy dissipation and particle heating. However, varying definitions of current sheets can lead to inconsistent results, and treating current sheets and the ambient solar wind as uniform entities may obscure the unique turbulent properties within these structures. By analyzing 117 typical current sheets near 1 au in the solar wind over the period from 2005 to 2017, we systematically investigate the turbulent properties of these current sheets. For the first time, we present a direct relationship between the magnetic field decrease rate, thermal energy increase, intermittency, and the magnetic power spectrum inside these structures. We observe a notable increase in proton temperature accompanied by a significant decrease in the magnetic field within the current sheets. Current sheets with larger magnetic field shear angles and more pronounced magnetic field drops tend to exhibit greater inhomogeneity at the sub-ion scale. Most importantly, our analysis reveals that the steeper magnetic field spectrum in the sub-ion range is directly associated with small-scale intermittent structures, a phenomenon observable only within current sheets and gradually diminishing over longer time scales. These results imply that the fine structures within the current sheets might affect the turbulent energy dissipation, and it is necessary to distinguish the current sheet itself from the ambient solar wind when studying turbulent properties and the associated energy dissipation processes.