Premium
Geomagnetic and solar wind fluctuations at discrete frequencies: A case study
Author(s) -
Villante U.,
Del Corpo A.,
Francia P.
Publication year - 2013
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2012ja017971
Subject(s) - magnetopause , solar wind , physics , earth's magnetic field , interplanetary magnetic field , geophysics , computational physics , magnetic field , perturbation (astronomy) , atmospheric sciences , astronomy , quantum mechanics
A worldwide analysis of geomagnetic field measurements, during a period of wave activity following an intense magnetospheric perturbation, revealed signals at discrete frequencies ( f ≈ 1.0, ≈1.9, ≈2.2–2.4, ≈2.6, ≈3.4–3.6, and ≈4.7 mHz) which are similar to the frequencies identified from auroral to low latitudes in previous investigations. All the power enhancements found correspondence in enhancements, approximately at the same frequencies, in the solar wind dynamic pressure, and/or speed and interplanetary magnetic field components. The modes dominant in the wide afternoon sector ( f ≈ 1.9, ≈2.6, and ≈3.4–3.6 mHz) were almost ubiquitously detected, and rough estimates of the propagation parameters appear consistent with those expected for standing cavity modes. The modes emerging in the morning sector ( f ≈ 1.0 and ≈2.2–2.4 mHz) appear related to the fluctuations of the magnetopause current, driven by those of the solar wind pressure.