Two simultaneous charge structures in thunderstorm convection

Abstract

A pair of simultaneous, horizontally displaced, thunderstorm electric field soundings are used to investigate an existing conceptual model of thunderstorm charge structure. The soundings show that two different vertical charge structures, one in the updraft and one outside the updraft, can exist at the same time inside a storm, as depicted in the existing model. The data suggest that the two charge structures can be relatively close together, since the soundings are separated by only 3 to 8 km horizontally in the convective region of the storm. Horizontal extent of the charge structures is estimated to be at least 4 km × 4 km. The differences in the two charge structures are coincident with substantial differences over this same 3 to 8 km horizontal distance in the reflectivity structure, updraft speed, and lightning activity of the convection. The nonupdraft sounding was made through the intense reflectivity core found at middle levels in the convection. Additional electric field complexity and additional charge regions were found in the nonupdraft sounding, and the lightning‐related electric field changes tended to be larger in magnitude and more numerous in that sounding than in the updraft sounding.