  The boundaries identification of Kelvin-Helmholtz vortices in observational
data has been addressed by searching for single-spacecraft small-scale
signatures. A recent hybrid Vlasov-Maxwell simulation of Kelvin-Helmholtz
instability has pointed out clear kinetic features which uniquely characterize
the vortex during both the nonlinear and turbulent stage of the instability. We
compare the simulation results with \textit{in situ} observations of
Kelvin-Helmholtz vortices by the Magnetospheric MultiScale satellites. We find
good agreement between simulation and observations. In particular, the edges of
the vortex are associated with strong current sheets, while the center is
characterized by a low value for the magnitude of the total current density and
strong deviation of the ion distribution function from a Maxwellian
distribution. We also find a significant temperature anisotropy parallel to the
magnetic field inside the vortex region and strong agyrotropies near the edges.
We suggest that these kinetic features can be useful for the identification of
Kelvin-Helmholtz vortices in \textit{in situ} data.
