Propagation of the Interplanetary Shock Induced Pulse: New Observations by the Global Navigation Satellite System

Abstract

AbstractWe revisited a typical interplanetary (IP) shock event on 7 November 2004, with high time resolution (1 s) total electron content (TEC) observations. The IP shock impinged on the dayside magnetopause at ∼18:27 UT, and launched a pulse into the magnetosphere. Using the multi‐spacecraft timing method, the pulse was estimated to propagate at an angular velocity of ∼0.1 MLT/s. While the in situ spacecraft observations only provided a first‐order estimation of the propagation speed, a more precise monitoring of the propagating pulse was achieved by the densely distributed network of the Global Navigation Satellite System (GNSS). Following the shock arrival, GNSS receivers throughout the equatorial region recorded the associated TEC impulses. The signatures were sequentially observed from the sub‐solar to the nightside via both flanks, which in turn demonstrated the concrete propagation pattern of the pulse. In addition to a consistent angular velocity, a ∼40 s difference was systematically found between the TEC measurements and the in situ spacecraft observations, revealing the timescale of the shock‐induced magnetospheric‐ionospheric coupling.