Figure 1

Integrated antenna voltage magnitude versus distance to lightning flash for TD1, with the distance obtained from the radio frequency (LINET) lightning location measurement for TD1 events which were time coincident. Black circles represent the summer data set (during May–August 2012), and purple squares 1–2 November 2012 data. The gray line indicates an inverse-cube relationship passing through the May–August data set.Reuse & Permissions

Figure 2

Map of LINET lightning flash locations for 1–2 November 2012 within 500 km of TD1 (cyan circle). Red and blue circles indicate positive and negative polarity flashes, respectively, with the circle diameter proportional to peak current. The cyan crosses represent flashes coincident with TD1 detections. The location of TD2 is shown as an orange circle, with orange crosses identifying flashes coincident with this detector.Reuse & Permissions

Figure 3

Normalized probability densities in 20 kA bins plotted vertically and back to back of peak flash current magnitudes for negative (blue) and positive (red) measured by LINET, during events which are (a) noncoincident and (b) coincident between LINET detections and either TD1 or TD2, and within 500 km of TD1.Reuse & Permissions

Figure 4

Currents (relative scale) detected by TD1 (Reading, black) and TD2 (Portishead, green), on 2 November 2012 for events within one second of a LINET reporting event (location given on left-hand panels by orange triangle) for (a) single stroke $-281\mathrm{kA}$ flash over southern Wales, 191 km from Reading and 65 km from Portishead, (b) a further nearby single stroke 267 kA flash over the Bristol Channel, 199 km from Reading and 72 km from Portishead, and (c) a distant single stroke 267 kA flash over North West England, 318 km from Reading and 286 km from Portishead.Reuse & Permissions

Figure 5

Relationship between surface electric field and distance from different charge configurations [see also Supplemental Material [14], Eqs. (1)–(4)]. The blue dotted line shows the inverse-cubed relationship from a single point source at 8 km altitude, representing the charge neutralized by a cloud(top)-to-ground flash. The green dashed line is for a tripole configuration, with equal magnitude point sources at 8, 10, and 80 km altitude (the 10 km being of opposite polarity). This represents cloud top CG charge, screening charge (SC) 2 km above and the upper termination of a sprite. The red line is for the same configuration as the green (sprite) model except the upper charge is spread into a 600 km disc of uniform charge density. The insert indicates the different charge configurations considered.Reuse & Permissions