Jovian electrons at the Earth orbit and stationary structures in the solar wind

Abstract

ABSTRACT This work studies the influence of the structure of inner heliospheric magnetic field on the propagation of Jovian electrons from Jupiter to the Earth orbit. Beginning from 1974, 13-month variations of relativistic Jovian electron fluxes were recorded by spacecraft near the Earth. 22 synodic cycles are analysed. The best connection in each cycle was found within a narrow longitudinal interval with an angular divergence of the planets 230 ± 20°, when the Parker field line connecting the two planets is formed at solar wind speed 450 ± 50 km s−1. Such invariability for more than 45 yr could not be accidental. We attribute the observed phenomenon to the long-term presence of recurrent stationary structures in the solar wind generated near the Sun. This assumption is confirmed by comparing the time profiles of the solar wind speed measured over all solar rotations in the solar activity minima in 1975 and 2007–2008.