Possible Evidence for Shear-driven Kelvin–Helmholtz Instability along the Boundary of Fast and Slow Solar Wind in the Corona

Abstract This paper reports the first possible evidence for development of Kelvin–Helmholtz (KH) instability at border coronal holes separating associated fast wind from slower originating adjacent streamer regions. Based on a statistical data set spectroscopic measurements UV corona acquired with UltraViolet Coronagraph Spectrometer board SOlar and Heliospheric Observatory during minimum activity solar cycle 22, high temperature–velocity correlations are found along fast/slow interface region interpreted as manifestations KH vortices formed by roll-up shear flow, whose dissipation could lead to higher heating and, because that, velocities. These observational results supported solving coupled turbulence transport equations including KH-driven source tangential velocity discontinuity between faster flows: numerical analysis indicates that correlation speed temperature is large in presence turbulence. findings suggest may play an important role both plasma dynamics energy deposition boundaries equatorial streamers.