Magnetospheric electric field from low latitude whistlers during magnetic storm

Abstract

An attempt has been made to estimate the east-west component (Ew) of the magnetospheric equatorial electric field near L = 1.12 during a magnetic storm period from the whistlers observed at our low latitude ground station, Nainital (geomag.lat. 19°1'N), on March 25, 1971 in the 0130-0500 IST sector. The method of measuring Ew from the observed cross L-motions of whistler ducts within the plasmasphere, indicated by changes in nose frequency of whistlers, has been outlined. The nose frequencies of non-nose whistlers under consideration have been deduced from Dowden-Allcock linear Q-technique. The variation of (f{hook}n) 2 3 with local time has been shown, the slope of which can be directly related to the convection electric field. The estimated equatorial electric field at L≅ 1.12 is in the range 0.1-0.5 mV m-1 (in the 0130-0500 IST sector) during a storm period, which is in agreement with the results reported by earlier workers. The departure from a dipole field and the contribution of an induced electric field from the temporal changes have been discussed. The importance of an electric field study has been indicated. © 1980.