The chromospheres of the Sun and solar-like stars respond to the underlying
magnetic activity. The spectral lines of singly ionized calcium (e.g., Ca
II K at 3933 Angstrom) exhibit single or double reversals and serve as diag
nostic tools for the magnetic activity. We present observations showing tha
t the Ca II K spectral Line may exhibit reversals in addition to the well-k
nown K1, K2, and K3 components, when observed with high angular and spectra
l resolution. These Ca II K spectral line anomalies occur when small-scale,
subarcsecond magnetic fields emerge through the chromosphere. The anomalou
s profiles originate at locations that are cospatial with H alpha brighteni
ng at footpoints of dark active region fibrils, or active region filaments.
The photospheric magnetic field is bipolar (small opposite polarity magnet
ic nodules) or has neutral lines at cospatial locations where the spectral
lines are anomalous. Small-scale reconnective processes can cause these ano
malous profiles. From a simultaneous time series of magnetic field data, we
find that the emerging magnetic flux is associated with these profiles. Th
e additional reversals primarily occur redward of the familiar K3 absorptio
n trough, implying chromospheric downflow velocities that lead to the forma
tion of shocks. The magnitude of the Doppler shift is of the order 40-50 km
s(-1). We present evidence to suggest that a combination of subresolution
elements, each of which has regular profiles with large relative Doppler sh
ifts could explain the formation of some of these profiles. A heuristic mod
el that combines buoyant magnetic fields, convective collapse, gas evacuati
on, shock formation, heating, and a multicomponent model atmosphere can rep
roduce these profiles.