Research Article

GPS scintillations associated with cusp dynamics and polar cap patches

¹ Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316 Oslo, Norway
² Arctic Geophysics, University Centre in Svalbard, N-9171 Longyearbyen, Norway
³ Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, P.B. 7803, 5020 Bergen, Norway
^a Now visiting Center for Space Science and Engineering Research (Space@VT), Virginia Tech, 1901 Innovation Drive, Blacksburg, VA 24060, USA

^* Corresponding author: yaqi.jin@fys.uio.no

Received: 7 June 2017
Accepted: 20 August 2017

Abstract

This paper investigates the relative scintillation level associated with cusp dynamics (including precipitation, flow shears, etc.) with and without the formation of polar cap patches around the cusp inflow region by the EISCAT Svalbard radar (ESR) and two GPS scintillation receivers. A series of polar cap patches were observed by the ESR between 8:40 and 10:20 UT on December 3, 2011. The polar cap patches combined with the auroral dynamics were associated with a significantly higher GPS phase scintillation level (up to 0.6 rad) than those observed for the other two alternatives, i.e., cusp dynamics without polar cap patches, and polar cap patches without cusp aurora. The cusp auroral dynamics without plasma patches were indeed related to GPS phase scintillations at a moderate level (up to 0.3 rad). The polar cap patches away from the active cusp were associated with sporadic and moderate GPS phase scintillations (up to 0.2 rad). The main conclusion is that the worst global navigation satellite system space weather events on the dayside occur when polar cap patches enter the polar cap and are subject to particle precipitation and flow shears, which is analogous to the nightside when polar cap patches exit the polar cap and enter the auroral oval.