Registration of synchronous geomagnetic pulsations and proton aurora during the substorm on March 1, 2017

Ilya Varlamov,Kazuo Shiokawa,Dmitry Baishev,Stanislav Parnikov,Igor Ievenko,A Dmitriev,Z Rakhmonov,G Vodinchar

doi:10.1051/epjconf/202125402012

Abstract

Data of synchronous geomagnetic pulsations and proton aurora registrations were analyzed during the substorm on March 1, 2017 at Zhigansk (L=4.5, induction magnetometer), Maimaga (L=4, all-sky imager and Yakutsk (L = 3.3, induction magnetometer) stations, simultaneously with satellite measurement of EMIC waves. Ground-based registration of proton aurora is very difficult due to the fact that their intensity is much lower than the aurora intensity caused by precipitations of electrons, but in the event of substorm activity at the zenith of Maimaga station, a narrow (1 degree in latitude) proton arc was observed. Irregular pulsations of the diminishing periods (IPDPs) in the range of Pc1 geomagnetic pulsations associated with the injection of energetic protons were recorded simultaneously at Zhigansk and Yakutsk stations. This is the first report when STEVE (Strong Thermal Emission Velocity Enhancement) was observed in the course of a substorm with the onset at 12:45 UT after the decay of Pc1-associated proton arc. It is shown that the proton arc and geomagnetic pulsations are a consequence of ion-cyclotron instability in the area of the outer plasmasphere overlapping by energetic protons.

Highlights

In the area of overlapping of the outer plasmasphere by ring current ions, many processes arise, the results of which, in particular, are electromagnetic ion cyclotron (EMIC) waves, mid-latitude stable auroral red (SAR) arcs and proton auroras, equatorward of the auroral oval
EMIC waves manifest themselves in the form of variations in the components of the magnetic field in the region of generation and geomagnetic pulsations of the Pc1 range on the Earth
The proton arc arising in the vicinity of the zenith of the optical observation station had an uneven glow along the latitude

Summary

Introduction

In the area of overlapping of the outer plasmasphere (plasmapause) by ring current ions, many processes arise, the results of which, in particular, are electromagnetic ion cyclotron (EMIC) waves, mid-latitude stable auroral red (SAR) arcs and proton auroras, equatorward of the auroral oval. SAR arcs are the result of heating the outer plasmasphere by energetic ring current ions. Protons undergo a recharge, as a result of which excited hydrogen atoms are formed. In the visible part of the spectrum, the Hα and Hβ lines are emitted by which the precipitation of protons from the Earth is identified. EMIC waves manifest themselves in the form of variations in the components of the magnetic field in the region of generation and geomagnetic pulsations of the Pc1 range on the Earth

Methods

Results

Conclusion