  We present results from a three-dimensional particle-in-cell simulation of
plasma turbulence, resembling the plasma conditions found at kinetic scales of
the solar wind. The spectral properties of the turbulence in the subion range
are consistent with theoretical expectations for kinetic Alfv\' en waves.
Furthermore, we calculate the local anisotropy, defined by the relation
$k_{\parallel}(k_{\perp})$, where $k_{\parallel}$ is a characteristic wave
number along the local mean magnetic field at perpendicular scale
$l_{\perp}\sim 1/k_{\perp}$. The subion range anisotropy is scale dependent
with $k_{\parallel}<k_{\perp}$ and the ratio of linear to nonlinear time scales
is of order unity, suggesting that the kinetic cascade is close to a state of
critical balance. Our results compare favorably against a number of \emph{in
situ} solar wind observations and demonstrate---from first principles---the
feasibility of plasma turbulence models based on a critically balanced cascade
of kinetic Alfv\' en waves.
