Subionospheric VLF signatures of oblique (nonducted) whistler‐induced precipitation

Abstract

Subionospheric very low frequency (VLF) signal perturbations observed at multiple sites in association with individual lightning discharges exhibit onset delays which steadily increase with increasing L ‐value. The timing of the onsets and the inferred spatial extent (∼1000 km) of the ionospheric disturbance are consistent with those expected for electron precipitation induced by obliquely propagating (i.e., nonducted) whistlers.