Study of the Geomagnetic Stoem of October 29, 1973

Abstract

Due to the absence of data for solar wind plasma parameters during the October 29, 1973 geomagnetic storm, the auroral electrojet (AE) index was employed for the study of the ionospheric response to the storm. The available interplanetary magnetic field component, B_z, and the low latitude magnetic index, D_st, showed that the storm was moderate (D_st = -64nT, B_z = -5.8nT). The analysis from the disturbances in ionospheric foF2 from October 29-31, 1973 showed predominantly an enhancement (positive storm) at the mid and low latitude stations. In between the time of storm (i.e. 14:00UT on 29 and 05:00UT on 30 October), the upper latitudes also showed some degree of enhancement. This paper concluded that the reason for this positive ionospheric storm across all latitudes could be injection of energy because of significant increase in the AE index, which caused an uplift of the ionospheric layers to higher altitudes, where the recombination rate was small. In addition, the paper attempted to confirm the argument that, moderate magnetic storms are capable of generating ionospheric storms, which are of comparable magnitude with those resulting from intense geomagnetic storms.

Keywords:Geomagnetic storm, moderate storm, solar wind, AE index, ionospheric storm

International Journal of Natural and Applied Sciences, 5(3): 229-234, 2009