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When observing spectral lines in the optically-thin corona, line-of-sight(LOS) effects can strongly affect the interpretation of the data, especially inregions just above the limb. We present a semi-empirical forward model, calledGHOSTS, to characterize these effects. GHOSTS uses inputs from several othermodels to compute non-equilibrium ionization states (which include thesolar-wind freezing-in effect) for many ions. These are used to generateensembles of simulated spectral lines that are examined in detail, withemphasis on: (1) relationships between quantities derived from observables andthe radial variation of the observed quantities, (2) the behavior of thermaland non-thermal components of the line width, and (3) relative contributions ofcollisionally excited and radiatively scattered photons. We find that rapidlychanging temperatures in the low corona can cause ion populations to varydramatically with height. This can lead to line-width measurements that areconstant with height (a "plateau" effect) even when the temperature isincreasing rapidly, as the plane-of-sky becomes evacuated and theforeground/background plasma dominates the observation. We find that LOSeffects often drive the velocity width to be close to the plane-of-sky value ofthe wind speed, despite it flowing perpendicularly to the LOS there. Theplateau effect can also cause the non-thermal component of the line width togreatly exceed the solar wind velocity at the observation height. Lastly, westudy how much of the LOS is significant to the observation, and the importanceof including continuum in the solar spectrum when computing the radiativelyscattered emission.

The Effect of Solar Wind Expansion and Non-Equilibrium Ionization on the Broadening of Coronal Emission Lines