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Variability of solar eruptions during cycle 23
Howard, R. A.; Gopalswamy, N.; Yashiro, S. +1 more
We report on the solar cycle variation of the rate of coronal mass ejections (CMEs), their mean and median speeds, and the rate of type II radio bursts. We found that both CME rate and speed (mean and median) increased from solar minimum to maximum by factors of 10 and 2, respectively. The CME rate during solar maximum is nearly twice the rates qu…
The origin of the slow solar wind in coronal streamers
Ofman, L.
The highly variable slow solar wind has been associated with low-latitude regions of the heliosphere most clearly by the Ulysses spacecraft. Although, it is evident today that the slow solar wind originates in coronal helmet streamers, the mechanism of the slow solar wind acceleration, and the origin of the variability are still being debated. The…
Low-latitude coronal holes during solar maximum
Cranmer, S. R.; Kohl, J. L.; Miralles, M. P.
The Ultraviolet Coronagraph Spectrometer (UVCS) on SOHO has been used to observe large low-latitude coronal holes during solar maximum that produced fast solar wind streams. UVCS observations show that large low-latitude coronal holes at solar maximum, coronal holes of at least 10° in longitude, have plasma properties that seem to bridge the gap b…
Flow in streamer boundaries, and streamer stability
Suess, S. T.; Nerney, S.
Streamers can extend to many solar radii but the closed field regions, or helmets, reach no higher than 2-4 solar radii. The brightness boundary defining streamers is therefore, a boundary between different flow regimes rather than between static plasma and expanding solar wind. It is reasonable to assume that, this boundary divides fast coronal h…
On coronal streamer changes
Howard, R. A.; Gopalswamy, N.; Shibasaki, K. +3 more
Coronal streamer represents one of the pre-eruption configurations of coronal mass ejections (CMEs), because they overlie prominences and often possess all the substructures of CMEs. In this paper, we report on a study of streamer changes associated with prominence eruptions. The prominence eruptions and streamer changes were observed by the Nobey…
Diagnostics of the Local Interstellar Medium using particles and UV radiation
Lallement, R.; Vallerga, J.; Raymond, J. R.
The chain of processes which govern trajectories and ionization of neutral particles from the circumsolar interstellar gas to the inner heliosphere can now be studied by combining several types of diagnostics: solar backscattered radiation (H and He), direct detection of neutral particles (He), detection of pickup ions of interstellar origin (H, H…
Suprathermal ions of solar and interstellar origin associated with the April 9-12, 2001, CMEs
Klecker, B.; Wimmer-Schweingruber, R. F.; Hilchenbach, M. +2 more
The distribution functions of suprathermal ions associated with the two interplanetary coronal mass ejections in the time period of April 9-12, 2001, are analyzed. The data on ions in the energy range 35-2000 keV/amu were recorded by the (Highly) Suprathermal Time-of-Flight (HSTOF/STOF) Spectrometer on board the Solar and Heliospheric Observatory …
Probing diffusion parameters of suprathermal ions near heliospheric shocks
Klecker, B.; Hilchenbach, M.; Kallenbach, R. +1 more
The distribution functions of suprathermal ions in the energy range 35-2000 keV/amu associated with the interplanetary coronal mass ejection of 14-16 July 2000 are analyzed. The ion spectra agree with a theoretical model on momentum diffusion in two-dimensional magnetohydrodynamic turbulence.