Engineering topics
Publications and source records attributed to Burlaga, L. F..
High time resolution measurements of the interplanetary magnetic field and plasma reveal a complex microstructure which includes hydromagnetic wave and discontinuities. The identification of hydromagnetic waves and discontinuities, their statistical properties, their relation to large-scale structure, and their relative contribution to power spectra are discussed.
Development of a theory of hydromagnetic waves and discontinuities which is appropriate for the solar wind. The experimental evidence for the various waves, discontinuities, and some of the instabilities which are predicted by this theory is reviewed. Nearly all of the discontinuities given by the theory are shown to exist in the solar wind. These include tangential discontinuities, forward and reverse fast and slow shocks, perpendicular shocks, and Alfven shocks. Parallel shocks and contact discontinuities have not been found. A number of special cases are considered which show the basic physical properties of hydromagnetic waves in an anisotropic, multifluid, collisionless plasma. A treatment of discontinuities is presented which most resembles those of Chao (1970) and Hudson (1970). On the basis of the experimental results reviewed it is concluded that hydromagnetic theory is applicable to the solar wind.
Probable reverse and forward slow shocks were found in plasma and magnetic-field data from Pioneer 6. The shocks were oblique and weak (Mach of approximately 1.2). No reverse fast shocks were found. Numerous (50) other discontinuities were found, most of which are probably tangential, since all the plasma parameters changed across most of them.
Processes which occur within the region between approximately 2 solar radii and 25 solar radii, which is called the solar envelope and the effect on the solar wind as seen at 1 AU are discussed. In the envelope the wind speed becomes supersonic and super-Alfvenic, the magnetic energy density is larger than the flow energy density, and the magnetic energy density is much larger than the thermal energy density. Large azimuthal gradients in the bulk speed are expected in the envelope, but the stream interactions near the outer edge of the envelope are probably relatively small. Cosmic ray observations suggest the presence of hydromagnetic waves in the envelope. The collisionless damping of such waves could heat protons out to approximately 25 solar radii and thereby cause an increase in V and T sub p consistent with the observed T sub p -V relation. A mechanism which couples protons and electrons would also heat and accelerate the wind. Alfven waves can accelerate the wind in the envelope without necessarily causing heating of protons; the Lorentz force might have a similar effect.
Large velocity discontinuities in solar wind in anisotropic medium
Magnetohydrodynamics of discontinuities in interplanetary medium and their relation to propagation and acceleration of cosmic rays
Solar wind rotational to tangential discontinuities ratio determination and hypothesis concerning origin in interplanetary magnetic field
Microstructure of solar wind and interplanetary medium
Reverse and forward slow shocks in solar wind from Pioneer 6 space probe
Hydromagnetic waves and discontinuities in solar wind
Comments on waves and discontinuities in solar wind
Characteristics of directional discontinuities in interplanetary magnetic field
Magnetic and thermal pressures in solar wind from Explorer 34 data
Reverse hydromagnetic shock in solar wind as discontinuity of plasma density, proton temperature and magnetic field density, using spacecraft data
Magnetic and kinetic pressures in solar wind
Measuring energy transfer at colliding streams in solar wind based on data from Explorer 34 and Vela 4B satellites
Solar wind flow behind shock fronts from Mariner 5 and Explorer 34 spacecraft
Anisotropic solar cosmic rays in inhomogeneous medium, investigating shell effect on propagation by one dimensional model