ELF magnetic field measurements from 10 to 135 Hz at Arrival Heights, Antarctica, are used as a proxy measure of global cloud-to-ground lightning activity. Simultaneous hourly recordings of the atmospheric electric field on the surface of the Earth at South Pole during December 1992 make possible a detailed comparison between global cloud-to-ground lightning activity and the atmospheric electric field. Although the mean diurnal variation of the ELF magnetic field anti the atmospheric electric field exhibit a remarkable similarity in shape and phase, the hourly departures from their mean diurnal variations are poorly correlated. We quantify the variability of the atmospheric electric field which can be explained by global cloud-to-ground lightning activity through linear regression analysis. To estimate an accuracy of this method, it is applied to simultaneous measurements of the ELF magnetic field at Sondrestromfjord, Greenland, for comparison. The resulting hourly contribution of global cloud-to-ground lightning activity to the atmospheric electric field in the Antarctic during December 1992 is similar to 40 +/- 10%, and the contribution of global cloud-to-ground lightning activity to hourly departures from the mean diurnal variation of the atmospheric electric field is similar to 25 +/- 10%.
|Number of pages||6|
|Journal||Journal of Atmospheric and Solar-Terrestrial Physics|
|Publication status||Published - 1999|