  The formation of shocks within the solar atmosphere remains one of the few
observable signatures of energy dissipation arising from the plethora of
magnetohydrodynamic waves generated close to the solar surface. Active region
observations offer exceptional views of wave behavior and its impact on the
surrounding atmosphere. The stratified plasma gradients present in the lower
solar atmosphere allow for the potential formation of many theorized shock
phenomena. In this study, using chromospheric Ca II 854.2nm spectropolarimetric
data of a large sunspot, we examine fluctuations in the plasma parameters in
the aftermath of powerful shock events that demonstrate polarimetric reversals
during their evolution. Modern inversion techniques are employed to uncover
perturbations in the temperatures, line-of-sight velocities, and vector
magnetic fields occurring across a range of optical depths synonymous with the
shock formation. Classification of these non-linear signatures is carried out
by comparing the observationally-derived slow, fast, and Alfv\'en shock
solutions to the theoretical Rankine-Hugoniot relations. Employing over 200,000
independent measurements, we reveal that the Alfv\'en (intermediate) shock
solution provides the closest match between theory and observations at optical
depths of log(tau) = -4, consistent with a geometric height at the boundary
between the upper photosphere and lower chromosphere. This work uncovers
first-time evidence of the manifestation of chromospheric intermediate shocks
in sunspot umbrae, providing a new method for the potential thermalization of
wave energy in a range of magnetic structures, including pores, magnetic flux
ropes, and magnetic bright points.
