“…The Kelvin‐Helmholtz (KH) instability driven by a large sheared flow (Chandrasekhar, ) is often considered as one of the major mechanisms of the “viscous‐like” interaction (Axford, ) between the solar wind and the Earth's magnetosphere during northward interplanetary magnetic field (IMF) conditions (Johnson et al, ). Nonlinear KH waves are ubiquitously observed by different spacecrafts (Chen & Kivelson, ; Eriksson et al, ; Fairfield et al, ; Hasegawa et al, , ; Li et al, ; Nakamura et al, ; Nykyri et al, ; Stawarz et al, ; Vernisse et al, ) at low latitudes under both northward and southward IMF conditions (Hwang et al, ; Kavosi & Raeder, ; Walsh et al, ; Yan et al, ), as well as at high latitudes for dawnward and duskward IMF conditions (Hwang et al, ; Ma, Otto, Delamere, et al, ), which are consistent with global magnetohydrodynamics (MHD) simulations (Guo et al, ; Hwang et al, ; Li et al, ; Merkin et al, ). Therefore, it is of importance to identify and quantify how efficiently the nonlinear KH instability transports magnetic flux, mass, flux tube entropy, and momentum.…”