Bow shock and magnetosheath waves at Mercury

Technical Report · Tue Jul 01 04:00:00 EDT 1975

OSTI ID:7240218

Fairfield, D H; Behannon, K W

Mariner 10 measurements at the Mercury bow shock provide examples where the magnetic field is approximately parallel or perpendicular to the bow shock normal. Upstream of a broad irregular parallel shock, left-hand circularly polarized waves are observed which cut off very sharply at approximately 4 Hz. Upstream of a perpendicular shock, right hand circularly polarized waves are observed which persist up to the Nyquist frequency of 12 Hz. Determination of the wave propagation vector as a function of frequency helps conclusively identify the waves as whistler mode waves propagating from the shock. The magnetosheath downstream of the parallel shock is disturbed more than that downstream of the perpendicular shock, particlarly below 1 Hz. In the latter case regular left-hand polarized waves observed slightly above the proton gyrofrequency are identified as ion cyclotron waves with wavelength approximately 300 km which are Doppler shifted up to their observed frequency. (auth)

• Research Organization: National Aeronautics and Space Administration, Greenbelt, Md. (USA). Goddard Space Flight Center
• OSTI ID: 7240218
• Report Number(s): N-75-32978; NASA-TM-X-70965; X-692-75-177
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DOPPLER EFFECT
ELECTROMAGNETIC RADIATION
ION PLASMA WAVES
ION WAVES
MAGNETIC FIELDS
MAGNETOPAUSE
MAGNETOSHEATH
MERCURY PLANET
NOISE
PLANETS
PLASMA WAVES
POLARIZATION
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
SHOCK WAVES
WAVE PROPAGATION
WHISTLERS