改写：changes over small portions of the BAL troughs rather than entire BALs varying which can be understood in terms of movements of substructures in the flows Changes in the ionizing flux should global

Instead of the entire BALs varying, the changes occur in small portions of the BAL troughs. These changes can be explained by the movements of substructures within the flows. If there are changes in the ionizing flux, it should affect the ionization in the flow globally. As a result, we would anticipate these changes to be visible over large portions of the BAL profiles rather than just a small velocity range.