Jets with Kelvin-Helmholtz waves at the Earth’s magnetopause under pure southward IMF conditions

The Kelvin-Helmholtz (KH) waves have been frequently observed during the northward interplanetary magnetic field (IMF) but have been much less frequently observed during the southward IMF. Here, we performed a 3D MHD simulation of a KH wave to investigate the evolution of KH instability under the pure southward IMF condition. In the linear phase of KH instability, there are almost no jet flows along northward and southward. In the nonlinear growth phase, the width of the KH vortex is about ∼12λ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\sim 12\lambda $\end{document}, and the duration time of the KH vortex is about ∼20tA\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\sim 20t_{A}$\end{document}. Moreover, the obvious jet flows whose peak Vz\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$V_{z}$\end{document} value is about ∼0.5VA\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\sim 0.5V_{A}$\end{document} are distributed in both the spine region and the edge of the KH vortex.