Curvature of Magnetic Field and Its Role on Plasma in Turbulent Magnetosheath

This study presents statistical features of magnetic field curvature in the magnetosheath region. Two sets of high-quality field and plasma data measured by the Magnetospheric Multiscale mission are analyzed by the multiple-point analysis method. The results include the following: (a) The probability distribution function (PDF) of the curvature exhibits two different power laws consistent with previous studies; the PDF of small curvatures depends on the plasma condition and the PDF of large curvatures shows better agreement. (b) The data validate the derived relation between the current density and the guiding center current as well as the diamagnetic current. (c) The acceleration due to curvature drifts in the perpendicular direction occurs when kappa/kappa (rms) is larger than 1, which is a potential mechanism for anisotropic distribution of plasma pressure at large curvatures.