Magnetic fields of the magnetosheath

Journal Article · Sun Feb 01 04:00:00 EST 1976 · Rev. Geophys. Space Phys., v. 14, no. 1, pp. 117-134

DOI:https://doi.org/10.1029/RG014i001p00117· OSTI ID:4024325

Fairfield, D H

The magnetic field of the magnetosheath is most naturally discussed in terms of its steady state and its fluctuating components. The theory of the steady state field is quite well developed, and its essential features have been confirmed by observations. The interplanetary field is convected through the bow shock where its magnitude is increased and its direction changed by the minimal amount necessary to preserve the normal component across the shock. Convection within the magnetosheath usually increases the magnitude still further near the subsolar point and further distorts the direction until the field is aligned approximately tangent to the magnetopause. Fluctuations of the magnetosheath field are very complex, variable, and not well understood. Power spectra of the field typically vary as 1/f or 1/f$sup 2$ below and 1/f$sup 3$ above the proton gyrofrequency. Spectral peaks are common features which occur at different frequencies at various times. Transverse waves are often dominant at frequencies less than or equal to 0.002 Hz, and compressional waves are often dominant at somewhat higher frequencies. Perturbation vectors of hydromagnetic waves tend to be aligned with the shock and magnetopause surfaces. Magnetosheath waves may be generated upstream, within the magnetosheath, at the bow shock, or at the magnetopause, but the relative importance of these sources is not known. 83 references. (auth)

• Research Organization: Goddard Space Flight Center, Greenbelt, MD
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-030988
• OSTI ID: 4024325
• Journal Information: Rev. Geophys. Space Phys., v. 14, no. 1, pp. 117-134, Journal Name: Rev. Geophys. Space Phys., v. 14, no. 1, pp. 117-134; ISSN RGPSB
• Country of Publication: United States
• Language: English

Related Subjects

*MAGNETOSHEATH-- MAGNETIC FIELDS
640203* --Physics Research--Atmospheric Physics-- Magnetospheric Phenomena
FLUCTUATIONS
GEOMAGNETIC FIELD
HYDROMAGNETIC WAVES
INTERPLANETARY MAGNETIC FIELDS
MAGNETOPAUSE
N58300* --Physics (Atmospheric)--Magnetospheric Phenomena
SOLAR WIND
SPECTRA
STEADY-STATE CONDITIONS
TIME DEPENDENCE
VARIATIONS