Lightning sferics and stroke‐delayed pulses measured in the stratosphere: Implications for mesospheric currents

During the Brazil Sprite Balloon Campaign 2002–03, the vector ELF to VLF (25 Hz–8 kHz) electric and magnetic fields driven by cloud‐to‐ground (CG) lightning strokes at horizontal distances of 75–600 km were measured at altitudes of 30–35 km. Electric field changes were measured for each of the 2467 CG strokes detected by the Brazilian Integrated Lightning Network. ELF pulses that occur 4–12 ms after the retarded time of the lightning sferic, which have been previously attributed to sprites, were found for 1.4% of 934 strokes examined. Thus, lightning‐driven electric and magnetic field changes were common and stroke‐delayed ELF pulses were rare, which disagrees with results from the Sprites99 Balloon Campaign.