Search Publications
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…
Magnetic clouds with east/west orientated axes observed by Ulysses during solar cycle 23
Forsyth, R. J.; Rees, A.
The second Ulysses orbit of the Sun has provided a unique opportunity for the study of the interplanetary manifestation of coronal mass ejections (ICMEs) over a wide range of heliographic latitudes. The Ulysses dataset between July 1995 and mid April 2003 has been surveyed for magnetic clouds (MCs), a subset of ICMEs. As a result of the rising sol…
VLF wave activity in the solar wind and the photoelectron effect in electric field measurements: Ulysses observations
Balogh, A.; McComas, D. J.; Lin, Naiguo +2 more
We present observations of very low frequency (VLF) waves (0.2 to 448 Hz) made by Ulysses during the solar maximum and compare the observations with those obtained when the solar activity was approaching a minimum. The occurrences and properties of the waves are found to be similar during the solar maximum and solar minimum periods for slow and in…
Ulysses Observations at Solar Maximum: Introduction
Smith, Edward J.; Marsden, Richard G.
Observations during Ulysses' second solar orbit reveal basic changes between solar minimum and maximum. Fast high latitude wind disappeared in the southern hemisphere allowing slow wind to expand to all latitudes. In the north polar cap, both fast wind and a polar coronal hole were present. The magnetic field polarity reversal was detected in the …
Low energy charged particles in the high latitude heliosphere: Comparing solar maximum and solar minimum
Lanzerotti, L. J.; Gold, R. E.; Maclennan, C. G.
Low energy charged particles in the global (3-D) heliosphere within ~2.3 AU of the Sun are compared during the two fast latitude scans by the Ulysses spacecraft at solar minimum and maximum. This comparison of data taken by the HISCALE instrument illustrates quantitatively the differences in the population of the heliosphere during the only two so…
Steady-state event-excluded proton spectra at solar minimum at all heliolatitudes
Armstrong, T. P.; Patterson, J. D.
We present spectra of a steady foreground population of particles in the inner heliosphere observed by the Heliosphere Instrument for Spectra, Composition, and Anisotopy at Low Energies (HISCALE) on board the Ulysses spacecraft. The observed spectra come from the full range of heliolatitudes visited by Ulysses, -80 to +80 degrees, during Ulysses' …
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…
Transition to solar minimum at high solar latitudes: Energetic particles from corotating interaction regions
Forsyth, R. J.; Sanderson, T. R.; Marsden, R. G. +2 more
One of the key questions to be addressed during the solar maximum phase of the Ulysses mission has been the nature of the ubiquitous energetic particle populations observed at all helio-latitudes from equator to poles. During the current, post-maximum phase of its mission, Ulysses has encountered the return to more stable solar wind, high speed st…
Motion of the dipolarization front during a flow burst event observed by Cluster
Balogh, A.; Zhang, T. L.; Dandouras, I. +12 more
In this paper we study a flow burst event which took place during enhanced geomagnetic activity on July 22, 2001, when Cluster was located in the postmidnight magnetotail. The flow burst was associated with a clear dipolarization ahead of the high-speed part of the predominantly Earthward directed flow. Based on the analysis of the four spacecraft…
The solar wind composition throughout the solar cycle: A continuum of dynamic states
Zurbuchen, T. H.; Gloeckler, G.; Fisk, L. A. +1 more
Variations in the speed and elemental and ionic charge composition of the solar wind are reported throughout the solar cycle, as observed by the SWICS instrument on Ulysses. The apparent bimodal nature of the solar wind during the solar minimum does not persist throughout the solar cycle. Rather, with increasing solar activity, a continuum of sola…