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Longitudinal Evolution of the Velocity of Subauroral Polarization Streams (SAPS) in Different Phases of Magnetic Storms: SuperDARN Observations
Author(s) -
Zhang Qiang,
Liu Yong C.M.,
Zhang Q.H.,
Xing ZanYang,
Ma YuZhang
Publication year - 2021
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2021ja029340
Subject(s) - substorm , magnetosphere , geomagnetic storm , geophysics , storm , physics , interplanetary magnetic field , ring current , magnetic field , phase velocity , geology , atmospheric sciences , computational physics , earth's magnetic field , solar wind , meteorology , optics , quantum mechanics
Abstract Investigations of the evolution of subauroral polarization streams (SAPS) are important to understand the plasma transport processes in the polar ionosphere. In this article, three cases of SAPS evolution are analyzed using the observations made by the Super Dual Auroral Radar Network mid‐latitude radar chain, Special Sensor Ultraviolet Spectrographic Imagers instrument and Active Magnetosphere and Planetary Electrodynamics Response Experiment. The three cases occur in the main phase, beginning of recovery phase and end of recovery phase of three magnetic storms. The cases last from 1.5 to 2 h during 1800–0300 MLT (magnetic local time). The observations show that the SAPS velocity evolution is strongly controlled by the ring current injection during the storm main phase. The responses of SAPS velocity are prompt and appear first near the dusk side and then expand to the night side. Besides, the SAPS velocity has a good linear correlation ( R = −0.85) with SYMH index during the evolution of the magnetic storm. The SAPS velocity also shows dependence on the AE index and interplanetary magnetic field (IMF) Bz. The correlations between SAPS velocity and AE/Bz increase with the decay of the magnetic storm. However, the effect of substorm/IMF on SAPS velocity is not strong compared to that of the magnetic storm.