  We perform local excitation calculations to obtain line opacities and
emissivity ratios and compare them with observed properties of H, He I, O I, Ca
II, and Na I lines to determine the density, temperature, and photon ionization
rate. We find that UV photoionization is the most probable excitation mechanism
for generating the He I 10830 opacities that produce all the associated
absorption features. We also calculate the specific line flux at an observed
velocity of v_obs = +/- 150 km/s for both radial wind and infall models. All
the model results, together with observed correlations between absorption and
emission features and between narrow and broad emission components, are used to
deduce the origins of the strong H, He I, and Ca II broad line emission. We
conclude that the first two arise primarily in a radial outflow that is highly
clumpy. The bulk of the wind volume is filled by gas at a density ~10^9 cm^-3
and optically thick to He I 10830 and H alpha, but optically thin to He I 5876,
Pa gamma, and the Ca II infrared triplet. The optically thick He I 5876
emission occurs mostly in regions of density greater than or equal to 10^11
cm^-3 and temperature greater than or equal to 1.5x10^4 K, while the optically
thick H alpha and Pa gamma emission occur mostly in regions of density around
10^11 cm^-3 and temperature between 8750 and 1.25x10^4 K. In producing the
observed line fluxes at a given v_obs, the covering factor of these emission
clumps is sufficiently small not to incur significant absorption of the stellar
and veiling continua in either He I or H lines. The strong Ca II broad line
emission likely arises in both the magnetospheric accretion flow and the disk
boundary layer, where the gases dissipate part of their rotational energies
before infalling along magnetic field lines. The needed density and temperature
are ~10^12 cm^-3 and less than or equal to 7500 K.
