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Properties of narrow coronal mass ejections observed with LASCO
Howard, R. A.; Gopalswamy, N.; Michalek, G. +1 more
We report the statistical properties of narrow coronal mass ejections (CMEs, angular width < 20°) withparticular emphasis on comparison with normal CMEs. We investigated 806 narrow CMEs from an online LASCO/CME catalog and found that (1) the fraction of narrow CMEs increases from 12% to 22% towards solar maximum, (2) during the solar maximum, t…
Solar maximum low-energy particle observations at heliographic latitudes above 75 degrees
Lario, D.; Reisenfeld, D. B.; Roelof, E. C. +1 more
We present a preliminary analysis of low-energy particle observations by the Ulysses and ACE spacecraft during the time intervals that Ulysses spent at heliographic latitudes above 75 degrees during its solar maximum orbit. The most southerly and northerly latitudes (80.2°) were reached by Ulysses in November 2000 and October 2001, respectively. T…
Soho observations relating to the association between flares and coronal mass ejections
Harrison, R. A.
Campaigns to investigate the solar coronal mass ejection (CME) onset have been run using the Solar andHeliospheric Observatory (SOHO) since 1996. These have included coronagraph and extreme-ultraviolet (EUV) disc imaging, along with magnetic mapping of the photosphere, in concert with EUV and UV spectroscopic observations. These campaigns have inc…
Particle drift effects on cosmic ray modulation during solar maximum
Ferreira, S. E. S.; Potgieter, M. S.; Heber, B.
A fully time-dependent cosmic ray modulation model based on the numerical solution of Parker's transport equation is used to study the amount of particle drifts needed to explain the observed 1.2 GV electron to Helium ratio at Earth and the 2.5 GV electron to proton ratio (e/p) observed by the KET instrument on the Ulysses spacecraft. The model su…
Energetic particle acceleration by coronal mass ejections
Kahler, S. W.
The current paradigm for the source of large, gradual solar energetic particle (SEP) events is that theyare accelerated in coronal/interplanetary shocks driven by coronal mass ejections (CMEs). Early studies established that there is a rough correlation between the logs of the CME speed and the logs of the SEP intensities. Here I review two topics…
Modulation of galactic cosmic rays at solar maximum: Observations
Zhang, Ming
The spectra of galactic cosmic rays observed anywhere inside the heliosphere are modulated by the sun because the charged particles must fight their ways inward against the radially expanding solar wind. In the past half a century, galactic cosmic ray fluxes at Earth were continuously monitored by neutron monitors on the ground and instruments on …
An XMM-Newton observation of the flare star AU MIC
Mewe, R.; Audard, M.; Güdel, M. +1 more
Preliminary results from an XMM- Newton observation of the active flare star AU Mic are presented. During the observation six flares were observed, along with numerous smaller-scale events. Coronal densities have been obtained using the density-sensitive He-like line triplet of O VII, for both the full observation and the final four flares. High b…
Wind-Ulysses in-situ thermal noise measurements of solar wind electron density and core temperature at solar maximum and minimum
Maksimovic, M.; Issautier, K.; Hoang, S. +2 more
The radio receivers on the Wind and Ulysses spacecraft in the solar wind continuously record spectra of the quasi-thermal plasma noise near the electron plasma frequency, from which the electron density and core temperature can be determined using the method of quasi-thermal noise spectroscopy. Such in-situ thermal noise measurements were obtained…
Coronal mass ejection interaction and particle acceleration during the 2001 April 14 15 events
Kaiser, M. L.; Howard, R. A.; Gopalswamy, N. +1 more
Two successive solar energetic particle (SEP) events associated with fast and wide coronal mass ejections (CMEs) on 2001 April 14 and 15 are compared. The weak SEP event of April 14 associated with an 830 km/s CME and an M1.0 flare was the largest impulsive event of cycle 23. The April 15 event, the largest ground level event of cycle 23, was thre…
First results of a new 3-D model of the time-dependent modulation of electrons in the heliosphere
Fichtner, H.; Ferreira, S. E. S.; Potgieter, M. S. +2 more
We employ our recently developed ansatz for the time-dependent 3-D modelling of Jovian and galactic electrons in the inner heliosphere. The main goal of the study is to check whether the form of the diffusion tensofi as determined recently by Ferreira et al. (2001a,b) with an extended parameter study of the steady state is also useful for comparis…