Simultaneous Observations of Daytime Whistlers and VLF-ELF Emissions at a Low Latitude Indian Ground Station

This paper reports an unexpected simultaneous observation of whistlers and different types of ELF/VLF emissions during daytime at a low latitude Indian ground station Jammu (geomag. lat., 22o 26/ N; L=1.17), which are (a) pulses of atmospheric bursts, (b) discrete chorus riser ELF emissions triggered from the bottom of the atmospherics, (c) whistlers, (d) whistler-triggered discrete chorus riser VLF emissions triggered from the lower end of the whistler, (e) long enduring ELF/VLF hiss emissions, (f) band limited quasi-periodic pulsing ELF/VLF hiss emissions, (g) hook and inverted hook ELF emissions, (h) oscillating tone discrete chorus riser ELF emissions. The data shown in this paper indicate that there is a strong possibility that lightning is an important source of different types of VLF/ELF emissions, at least in the embryonic sense, recorded at Jammu. The present observation is in fact the first simultaneous occurrence of different types of VLF/ELF emissions alongwith whistlers recorded on a single day during daytime at a low latitude ground station.