A Study of Whistling Atmospherics. I. Occurrence

The occurrence of whistling atmospherics at four Australian stations (Brisbane, Adelaide, Hobart, and Macquarie Island) over the LG.Y. period is discussed. A strong seasonal variation is observed at each station, with the maximum occurrenceduring local winter, and also a strong diurnal variation with a minimum during daylight hours. Whistlers are observed more commonly at about geomagnetic latitude 45 . Autocorrelation analysis suggests recurrence tendencies in the occurrence figures and cross correlation with sunspot numbers and Adelaide data indicates an association between the two. There is little evidence of association between whistler occurrence .and magnetic planetary index.