GPS scintillations associated with cusp dynamics and polar cap patches

TL;DR

This study examines how cusp dynamics and polar cap patches influence GPS scintillation levels, revealing that polar cap patches combined with auroral activity cause the highest scintillation, impacting space weather effects on navigation systems.

Contribution

It provides new observational evidence linking polar cap patches and cusp auroral activity to increased GPS phase scintillations, highlighting conditions that worsen space weather impacts.

Findings

Polar cap patches with auroral activity cause highest GPS scintillations.

Cusp dynamics alone cause moderate scintillations.

Polar cap patches away from cusp cause sporadic scintillations.

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.