Characteristics of lightning associated transient perturbations in low latitude VLF paths

Here we have reported some characteristics of lightning associated transient perturbations of Very Low Frequency signals detected over two tropical VLF paths; VTX-Kolkata and NWC-Kolkata. All types of events with positive and negative perturbations, very short to long recovery time have been found in nighttime. We explain positive and negative VLF amplitude deviations due to lightning events using the most well-known Long Wavelength Propagation Capability (LWPC) code. We find the location and size of ionospheric perturbations on the propagation paths by comparing the model results with observations.