Search Publications
Large solar energetic particle events of cycle 23: A global view
Thompson, B. J.; Kaiser, M. L.; Howard, R. A. +4 more
We report on a study of all the large solar energetic particle (SEP) events that occurred during the minimum to maximum interval of solar cycle 23. The main results are: 1. The occurrence rate of the SEP events, long-wavelength type II bursts and the fast and wide frontside western hemispheric CMEs is quite similar, consistent with the scenario th…
A statistical study of CMEs associated with metric type II bursts
Gopalswamy, N.; Yashiro, S.; Lara, A. +2 more
We present a statistical study of the characteristics of CMEs which show temporal association with type II bursts in the metric domain but not in the decameter/hectometric (DH) domain. This study is based on a set of 80 metric (m) type II bursts associated with surface events in the solar western hemisphere. It was found that in general, the distr…
Properties of high-latitude CME-driven disturbances during Ulysses second northern polar passage
St. Cyr, O. C.; Reisenfeld, D. B.; Forsyth, R. J. +2 more
Ulysses observed five coronal mass ejections (CMEs) and their associated disturbances while the spacecraft was immersed in the polar coronal hole (CH) flow above 70° N in late 2001. Of these CMEs, two were very fast (>850 km s-1) driving strong shocks in the wind ahead, and two others were over-expanding. The two fast CMEs were obser…
Long-duration hectometric type III radio bursts and their association with solar energetic particle (SEP) events
MacDowall, R. J.; Bougeret, J. L.; Lara, A. +3 more
It has recently been suggested by Cane et al. [2002] that a class of type III solar radio bursts, called type III-l, is reliably associated with intense solar energetic particle (SEP) events. They proposed that the causative electrons for these bursts are accelerated in regions of reconnecting magnetic field in the wakes of coronal mass ejections …
On the origin of inner-source pickup ions
Wimmer-Schweingruber, Robert F.; Bochsler, Peter
In situ measurements of pickup ions (PUI) exhibit a component that has nearly thermalized with the solar wind. This implies an origin close to the Sun and is generally ascribed to interaction of the solar wind with interplanetary dust particles (IDPs). We propose a scenario for the origin of inner-source PUIs in which a population of very small ID…
Relationship between CME velocity and active region magnetic energy
Venkatakrishnan, P.; Ravindra, B.
We find an empirical relationship between the initial speed of Coronal Mass Ejection (CME) and the potential magnetic field energy of the associated active region (AR) that closely resembles the Sedov relation between the speed of a blast wave and the blast energy. We conclude that it is the magnetic energy of an AR that drives the CME. The restru…
Are CME ``interactions'' really important for accelerating major solar energetic particle events?
Szabo, Adam; Richardson, Ian G.; Haggerty, Dennis K. +2 more
Recent studies have proposed that the presence or absence of an ``interaction'' with a preceding coronal mass ejection (CME) or other coronal structure within ~50 Rs of the Sun discriminates large, fast CMEs associated with major solar energetic particle (SEP) events from those that are not. We conclude that there is no compelling evide…
Plane-of-sky simulations of interplanetary shock waves
Dryer, M.; Smith, Z.; Fry, C. D. +3 more
We present simulated plane-of-sky maps of the shock waves in interplanetary space from several representative solar events by using the Hakamada-Akasofu-Fry solar wind model (HAFv.2). This kinematic model uses a three-dimensional approach to construct plane-of-sky maps of interplanetary shock waves initiated by solar flares and CMEs. The simulated…
Filament eruption without coronal mass ejection
Moore, Ronald L.; Choudhary, Debi Prasad
We report characteristics of quiescent filament eruptions that were not associated with coronal mass ejections (CMEs). We examined 12 quiescent filament eruptions, each of which was located far from disk center (>=0.7 RSun) in diffuse remnant magnetic fields of decayed active regions, was well observed in full-disk movies in Hα and F…
Inverse projection method for determination of distribution of real CME latitudes applied to the 1997-1998 SOHO LASCO observations
Skirgiello, Marta
Coronograph observations of coronal mass ejections (CMEs) do not provide the real latitude of their origin. The registered apparent latitude is the projection of the CME trajectory on the plane of the sky, and it may considerably differ from their original location. We show in this paper, how the projection effects can be eliminated from CME latit…