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Observations of ULF waves on the ground and ionospheric Doppler shifts during storm sudden commencement
Author(s) -
Ouyang Xinyan,
Liu Wenlong,
Xiao Zuo,
Hao Yongqiang
Publication year - 2016
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2015ja022092
Subject(s) - ionosphere , doppler effect , ultra low frequency , geophysics , physics , magnetometer , doppler frequency , storm , magnetic field , meteorology , acoustics , astronomy , quantum mechanics
Using data from ground‐based magnetometers and HF Doppler sounder, we study ultralow frequency (ULF) waves excited during the storm sudden commencement (SSC) on 8 March 2012 and find possible evidence on the link between ULF waves and ionospheric Doppler shifts. Pc1–Pc2 ULF waves are observed from 11:04 to 11:27 UT after the SSC by ground stations of L shell ranging from 1.06 to 2.31, mapping to the topside ionosphere. There are weak responses in this frequency range in the power spectra of ionospheric Doppler shift. From 11:19 to 11:23 UT, oscillations of magnetic field in a lower frequency range of Pc3–Pc4 are observed and are well correlated with the trace of Doppler shift. It is thus suggested that ionospheric Doppler shift can response to ULF oscillations in magnetic field in various frequency ranges, especially in the frequency range of Pc3–Pc4 and below. This paper demonstrates a new mechanism of magnetosphere‐ionosphere coupling.