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Streamer disconnection events observed with the LASCO coronagraph
Lamy, P. L.; Howard, R. A.; Sheeley, N. R., Jr. +2 more
We present Large Angle Spectrometric Coronagraph (LASCO) observations of two events that suggest magnetic disconnection in coronal streamers. During the 1-2 days preceding each event, successions of narrow looptops are seen rising slowly through the 2-6 RS field of view, forming a bright streamer stalk which continues to elongate with t…
Evidence of a solar origin for pressure balance structures in the high-latitude solar wind
Reisenfeld, D. B.; McComas, D. J.; Steinberg, J. T.
Ulysses observations of the high-latitude solar wind have shown that on time scales of < 1 day, the polar wind is dominated by pressure balance structures (PBSs). Fluctuations of the plasma beta within PBSs appear to be strongly correlated with fluctuations in the helium abundance. The correlation occurs in both the northern and southern hemisp…
Differences in the temporal variations of galactic cosmic ray electrons and protons: Implications from Ulysses at solar minimum
Sierks, H.; Kunow, H.; Bothmer, V. +8 more
According to standard drift dominated modulation models the intensity variations of galactic cosmic ray protons and electrons respond differently to the latitudinal extension of the heliospheric current sheet α. In an A>0 solar cycle intensities of protons should vary weakly with the latitudinal extension, whereas electrons should show a strong…
The global nature of solar cycle variations of the solar wind dynamic pressure
Wang, Chi; Richardson, John
The solar wind dynamic pressure measured near the ecliptic varies over the solar cycle. A major unanswered question has been whether this variation is a global feature or restricted to low latitudes and thus perhaps a consequence of the changing heliospheric current sheet configuration. We use plasma data from IMP-8, Ulysses and Voyager 2 to show …
Direct evidence of the interstellar gas flow velocity in the pickup ion cut-off as observed with SOHO CELIAS CTOF
Bochsler, P.; Klecker, B.; Möbius, E. +9 more
He+ pickup ions as observed with SOHO CELIAS CTOF have been analyzed for the time period DOY 160-190, 1996. During this time of the year the Earth is on the upwind side of the interstellar gas flow with respect to the sun. The high-speed cut-off in the frame of the sun is significantly higher v/Vsw = 2, predicted for pickup i…
Ion-cyclotron wave dissipation channel for Alfvén waves
Kaghashvili, Edisher Kh.
The effect of inhomogeneous velocity flow on Alfvén wave dynamics in the solar wind is investigated. Unlike existing studies in this field that model energy deposition from high-frequency waves to solar wind particles, we consider here the possibility of obtaining high-frequency waves (in this case fast magnetosonic waves) from the ordinary Alfvén…
Ulysses measurements of variations in the solar wind-interstellar hydrogen charge exchange rate
McComas, D. J.; Gosling, J. T.; Pryor, W. R. +1 more
Charge exchange with solar wind protons is the primary ionization process for interstellar hydrogen traveling through the heliosphere. In this study we use Ulysses solar wind observations to examine and quantify variations in charge exchange. We find that these variations are largest within stream interaction regions where the charge exchange rate…
Radial evolution of density structure in the solar corona
Habbal, Shadia Rifai; Woo, Richard
White-light measurements made by the SOHO coronagraphs (LASCO for Large Angle Spectrometric Coronagraph) and the HAO Mauna Loa Mk III K-coronameter are combined to follow the evolution of path-integrated density structure in the solar corona overlying both coronal hole and quiet Sun regions from 1.15 to 5.5 Ro. The global imaging provid…
Observations of heliospheric planar and offset-planar magnetic structures
Balogh, A.; Jones, G. H.; Horbury, T. S.
Planar magnetic structures are regions of solar wind plasma where the magnetic field orientation is constrained within a fixed plane for durations of several hours. Within these structures, magnetic field discontinuities are seen, with the discontinuity surfaces being almost co-planar. The results of a survey of planar magnetic strutures detected …
The electron heat flux in the polar solar wind: Ulysses observations
Scime, Earl E.; Littleton, J. E.; Badeau, Allen E., Jr.
Ulysses measurements of the solar wind electron heat flux as a function of heliographic latitude are presented. Contamination from a light leak at the highest latitudes has been removed from the data by interpolating between uncontaminated pixels. After normalization by the radial gradient in the electron heat flux obtained during the inecliptic p…