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The variability of the broad absorption lines is investigated for a broadabsorption line (BAL) QSO, SDSS J022844.09+000217.0 (z = 2.719), with 18SDSS/BOSS spectra covering 4128 days in the observed frame. With the ratio ofthe rms spectrum to the mean spectrum, the relative flux change of theBAL-trough is larger than that of the emission lines and the continuum. Fittingthe power-law continuum and the emission line profiles of \civ $\lambda$1549and \siiv$\lambda$1399, we calculate the equivalent width (EW) for differentepochs, as well as the continuum luminosity and the spectral index. It is foundthat there is a strong correlation between the BAL-trough EW and the spectralindex, and a weak negative correlation between the BAL-trough EW and thecontinuum luminosity. The strong correlation between the BAL-trough EW and thespectral index for this one QSO suggests that dust is intrinsic to outflows.The weak correlation between the BAL variability and the continuum luminosityfor this one QSO implies that the BAL-trough variation is not dominated byphotoionization.

Variability of broad absorption lines in a QSO SDSS J022844.09+000217.0 on multi-year timescales