VHF radio response of the near Earth space during solar activity growth in October, 2003

Abstract

The analysis of observations of very high frequency radio noise intensity at the middle latitude on a frequency f=500MHz from 14th till 26th of October, 2003 is presented. These data are compared with the solar radio bursts in the range of frequencies 1–14MHz registered by RAD2 receiver of the WAVES device installed on board the WIND spacecraft.The sporadic enhancement of near Earth very high frequency radio noise were observed with the help of ground radio telescope preferably either in pre mid night hours or at daytime. In many cases between October 17 and 22 short-term increases of the fluxes of low energy electrons, protons and ions in the interplanetary space by hundreds of times, corresponded to VHF radio bursts. At the same time slow increasing of solar cosmic rays streams at Lagrange point L1 and on geostationary orbit during October, 21 and 22, did not affect the usual radio noise level. A strong solar flare of 1B/X5.5 class on October 23 contributed to a prolonged rise of the intensity level of spectral radio emission, including the night sector of magnetosphere. It is assumed that very high frequency radio bursts in the near Earth space may appear when the processes of penetration of interplanetary low energy charge particles into Earth plasmasphere take place.