Search Publications
Thermal anisotropies in the solar wind: Evidence of heating by interstellar pickup ions?
Phillips, John L.; Richardson, John D.; Smith, Charles W. +1 more
A recent paper by Gray et al. [1996] shows that the Alfvén ion cyclotron instability is generated by newly created pickup ions and heats the thermal solar wind protons in the direction perpendicular to the magnetic field. This instability operates most effectively in regions where the plasma β is low, so this mechanism predicts that the ratio of t…
Observations of a sky Lyman α groove related to enhanced solar wind mass flux in the neutral sheet
Bertaux, Jean-Loup; Lallement, Rosine; Quémerais, Eric
We report several observations of the Lα interplanetary emission recorded by a photometer flown in 1977 on board the soviet spacecraft Prognoz-5. The Prognoz scans sampled emission in a plane perpendicular to the sun-spacecraft line and also traversed the Lα maximum emission region (MER), a region centered a few AU from the Sun on the upstream int…
Interstellar pickup H+ Ions at 8.3 AU: Pioneer 10 plasma and magnetic field analyses
Intriligator, Devrie S.; Siscoe, George L.; Miller, W. David
Analysis of Pioneer 10 plasma and magnetic field observations at 8.3 AU in 1975 provides new evidence for the presence of interstellar pickup hydrogen (H+) ions. Use of plasma sensors that look far from the solar wind direction confirms the spherical shell distribution of the pickup ions in velocity space. Phase space density and flux e…
Type III bursts observed simultaneously by Wind and Ulysses
Bougeret, J. -L.; Hoang, S.; Leblanc, Y. +1 more
We consider a period of five months when Ulysses was passing behind the Sun as viewed from Wind and measure the low frequency cutoffs flo and the local plasma frequency fp for 303 bursts seen by one, the other, or both spacecraft. The preliminary results are: 1) 68% of the bursts were seen on dynamic spectra of both spacecraf…
A novel method to measure the solar wind speed
Moncuquet, Michel; Issautier, Karine; Meyer-Vernet, Nicole +1 more
We propose a novel method to measure in situ the bulk speed of a space plasma. It is based on the analysis of the electrostatic field spectrum produced by the Doppler-shifted thermal fluctuations of the plasma ions which can be measured with a sensitive receiver at the terminals of a passive electric antenna. We present a preliminary application i…
Reply [to “Comment on ‘The underlying magnetic field direction in Ulysses observations of the southern polar heliosphere’ by Forsyth et al.”]
Balogh, A.; McComas, D. J.; Forsyth, R. J. +2 more
Interplanetary observations of solar g-mode oscillations?
Riley, Pete; Sonett, C. P.
By applying spectral techniques to magnetic field and plasma data from Helios 1 and 2, Pioneer 1 and 2, and Voyager 1 and 2 missions, an attempt has been made to find evidence for solar g-mode oscillations in the solar wind. It is demonstrated that analysis employing simple spectral techniques is unlikely to detect such oscillations. Using the mul…
Corotating shock accelerated particles guided by wavy spiral magnetic fields in the solar wind at high heliographic latitudes
Lou, Yu-Qing
We propose the persistent presence of randomly fluctuating, large-amplitude, long-timescale wavy spiral magnetic fields in the solar wind at all heliographic latitudes. These Alfvénic fluctuations can be generated by gradual evolution of solar coronal holes or by interplanetary Kelvin-Helmholtz instabilities occurring around the two conical interf…
Latitudinal variation of the heliospheric magnetic field during solar minimum
Bravo, S.; Stewart, G. A.
Ulysses' observations of the heliospheric magnetic field have shown that, above a narrow low-latitude region, the intensity of the radial component of the field is independent of latitude. Here we present a theoretical explanation of this behaviour based on an MHD model of the solar wind applicable at solar minimum, which corresponds to the Ulysse…
Kinetic temperature ratios of O6+ and He2+: Observations from Wind/MASS and Ulysses/SWICS
Cohen, C. M. S.; Gloeckler, G.; Wilken, B. +4 more
We present results from a two spacecraft study of the ratio of O6+ and He2+ kinetic temperatures as a function of solar wind speed. Data from the Wind/MASS and Ulysses/SWICS instruments both indicate the O6+/He2+ kinetic temperature ratio increases with increasing solar wind speed, peaking near 500 km/s.…