Does the altitude of the charge source region influence stroke multiplicity?
Candace L. Cyrek, Texas Tech University, Lubbock, TX; and K. C. Wiens Many differences exist between positive and negative cloud-to-ground (CG) lightning flashes, though these differences are not well understood. Observations show that negative CG flashes tend to have multiple return strokes with little continuing current from each stroke, whereas positive CG flashes tend to have only one return stroke with continuing current. Though the reason for this polarity asymmetry in terms of multiple strokes has not been identified, the leading hypothesis is related to the idea that the return stroke channel needs to be maintained by infusion of current from within the cloud. Insufficient infusion of current in the initial return stroke may lead to channel decay, thus resulting in a successive stroke. However, if this infusion of current is sufficient enough to maintain the initial stroke channel, then there may be large continuing current down the initial channel and no subsequent strokes. On
