NUMERICAL-SIMULATION OF WHISTLER-TRIGGERED VLF EMISSIONS OBSERVED IN ANTARCTICA

The British Antarctic Survey VLF database from Halley (L = 4.3) and Fa raday (L 2.3) stations, Antarctica, has been searched for clear exampl es of whistler-triggered emissions (WTEs). Dominant events were the tr iggering of risers or quasi-constant frequency emissions from the uppe r arm of a whistler. A fairly frequent occurrence was the triggering o f steep fallers from the whistler upper arm. At Faraday most WTE event s were the triggering of long steep risers from the lower whistler arm . A VHS/VLF Vlasov hybrid simulation code was run and successfully sim ulated the main categories of WTE: risers and fallers off the upper ar m and risers from the lower arm. Agreement with observations was gener ally very good, although in the case of triggered fallers and risers f rom the lower arm, very high frequency sweep rates were not obtained. The Vlasov code is highly efficient and well suited to this problem.