Charge transfer during intracloud lightning from a time-dependent multidipole model

[1] A time-dependent, multidipole (TDMD) model has been developed to show the charge transfer during intracloud (IC) flashes with high time and space resolution. This model combines high-speed electric field measurements from a balloon-borne instrument (Esonde) and three-dimensional lightning maps from the New Mexico Tech Lightning Mapping Array (LMA). The result is a time-varying spatial distribution of charge along lightning channels, which reveals several details about charge transfer during IC flashes. For example, a flash in 2004 initially deposited negative charge in one region and later transferred part of it to another region at a lower altitude where the negative leader was more highly branched. A flash in 2007 shows charge distributions along a main channel and two short branches; each of the three channels had different charges per unit length of channel.