Hydromagnetic Waves in the Magnetosphere and the Ionosphere

Alperovich, L.; Fedorov, E. N.

doi:10.1007/978-1-4020-6637-5

Cited by 103 publications

(87 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Magnetic field is inclined by angle I to the Earth's surface. Here we use some theoretical concepts from the thin sheet approximation (Alperovich and Fedorov, 2007) necessary for the interpretation of the results of simultaneous observations at low-orbiting satellite and ground stations.…”

Section: Model Of Mhd Wave Penetration To the Ground At Low Latitudesmentioning

confidence: 99%

Near-equatorial Pi2 and Pc3 waves observed by CHAMP and on SAMBA/MAGDAS stations

Cuturrufo

Pilipenko

Heilig

et al. 2015

Advances in Space Research

View full text Add to dashboard Cite

We have examined simultaneous ULF activity in the Pi2 and Pc3 bands at the near-equatorial magnetic stations in South America from SAMBA and MAGDAS arrays and low-orbiting CHAMP satellite during its passage over this meridional network. At the nighttime, both Pi2 and Pc3 waves in the upper ionosphere and on the ground are nearly of the same magnitude and in-phase. At the same time, the daytime Pc3 pulsations on the ground and in space are nearly out-of-phase. Comparison of observational results with the theoretical notions on the MHD wave interaction with the system ionosphere-atmosphere-ground suggests that nighttime low-latitude Pi2 and Pc3 wave signatures are produced by magnetospheric fast compressional mode. The daytime near-equatorial Pc3 waves still resist a quantative interpretation. These waves may be produced by a combination of two mechanisms: compressional mode leakage through the ionosphere, and by oscillatory ionospheric current spreading towards equatorial latitudes.

show abstract

Section: Model Of Mhd Wave Penetration To the Ground At Low Latitudesmentioning

confidence: 99%

Near-equatorial Pi2 and Pc3 waves observed by CHAMP and on SAMBA/MAGDAS stations

Cuturrufo

Pilipenko

Heilig

et al. 2015

Advances in Space Research

View full text Add to dashboard Cite

show abstract

“…Below we present a model and numerical results for the problem of magnetohydrodynamic wave transmission through and reflection from the ionosphere within a more realistic "thick ionosphere" model (Knudsen et al, 1992). Our analysis follows the scheme developed by Budden (1966) and Alperovich and Fedorov (2007). It is shown in Sect.…”

Section: Model Calculationsmentioning

confidence: 99%

Pc2-3 geomagnetic pulsations on the ground, in the ionosphere, and in the magnetosphere: MM100, CHAMP, and THEMIS observations

Yagova

Heilig²,

Fedorov

2015

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. We analyze Pc2-3 pulsations recorded by the CHAMP (CHAllenging Minisatellite Payload) satellite in the F layer of the Earth's ionosphere, on the ground, and in the magnetosphere during quiet geomagnetic conditions. The spectra of Pc2-3 pulsations recorded in the F layer are enriched with frequencies above 50 mHz in comparison to the ground Pc2-3 spectra. These frequencies are higher than the fundamental harmonics of the field line resonances in the magnetosphere. High quality signals with dominant frequencies 70-200 mHz are a regular phenomenon in the F layer and in the magnetosphere. The mean latitude of the maximum Pc2-3 occurrence rate lies at L ≈ 3.5 in the F layer, i.e., inside the plasmasphere. Day-to-day variations of the L value of the CHAMP Pc2-3 occurrence rate maximum follow the plasmapause day-to-day variations. Polarization and amplitude of Pc2-3s in the magnetosphere, in the ionosphere, and on the ground allow us to suggest that they are generated as fast magnetosonic (FMS) waves in the outer magnetosphere and are partly converted into shear Alfven waves near the plasmapause. The observed ground-to-ionosphere amplitude ratio during the night is interpreted as a result of the Alfven wave transmission through the ionosphere. The problem of wave transmission through the ionosphere is solved theoretically by means of a numerical solution of the full-wave equation for the Alfven wave reflection from and transmission through a horizontally stratified ionosphere. The best agreement between the calculated and measured values of the ground-to-ionosphere amplitude ratio is found for k = 5 × 10 −3 km −1 , i.e., the observed ground-to-ionosphere amplitude ratio corresponds to a wave spatial scale which could provide a Doppler shift within a few percent of the apparent frequency of the Pc2-3 pulsations as recorded by a loworbiting spacecraft.

show abstract

“…1388 A. G. Khantadze et al: Electromagnetic oscillations of the Earth's upper atmosphere by the fact that the fast wavy motions in the slow weatherforming processes create only "meteorological noise" and, therefore, they need to be filtered in advance. Indeed, in following numerous observations (Kelley, 1989;Alperovich and Fedorov, 2007), the real atmosphere quickly restores the violation of both quasi-static (during several minutes) and quasi-geostrophic (roughly during one hour) states. Thus, for the synoptic processes (two weeks and more), it may be considered that the atmosphere always is in the quasi-static and quasi-geostrophic states.…”

Section: Introductionmentioning

confidence: 67%

“…Consequently, the solution of the Cauchy problem for this system of equations requires the setting of the five fields of meteorological elements at the initial time. According to the observations (Kelley, 1989;Alperovich and Fedorov, 2007), wavy motions in the troposphere, propagating under the arbitrary initial conditions, can be clearly divided into relatively slow (synoptic) and fast motions. Slow wavy structures in the troposphere are always of a large-scale (with wavelength λ ∼ 10 3 − 10 4 km) and longperiod (from two days to two weeks and more) nature and move in the atmosphere with the velocities exceeding zonal winds (5-20 m s −1 ).…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic oscillations of the Earth's upper atmosphere (review)

et al. 2010

View full text Add to dashboard Cite

Abstract.A complete theory of low-frequency MHD oscillations of the Earth's weakly ionized ionosphere is formulated. Peculiarities of excitation and propagation of electromagnetic acoustic-gravity, MHD and planetary waves are considered in the Earth's ionosphere. The general dispersion equation is derived for the magneto-acoustic, magnetogravity and electromagnetic planetary waves in the ionospheric E-and F-regions. The action of the geomagnetic field on the propagation of acoustic-gravity waves is elucidated. The nature of the existence of the comparatively new largescale electromagnetic planetary branches is emphasized.

show abstract

Hydromagnetic Waves in the Magnetosphere and the Ionosphere

Cited by 103 publications

References 0 publications

Near-equatorial Pi2 and Pc3 waves observed by CHAMP and on SAMBA/MAGDAS stations

Near-equatorial Pi2 and Pc3 waves observed by CHAMP and on SAMBA/MAGDAS stations

Pc2-3 geomagnetic pulsations on the ground, in the ionosphere, and in the magnetosphere: MM100, CHAMP, and THEMIS observations

Electromagnetic oscillations of the Earth's upper atmosphere (review)

Contact Info

Product

Resources

About