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Magnetohydrodynamic modeling of the solar corona during Whole Sun Month
Thompson, B. J.; Forsyth, R. J.; Biesecker, D. A. +7 more
The Whole Sun Month campaign (August 10 to September 8, 1996) brought together a wide range of space-based and ground-based observations of the Sun and the interplanetary medium during solar minimum. The wealth of data collected provides a unique opportunity for testing coronal models. We develop a three-dimensional magnetohydrodynamic (MHD) model…
Solar minimum streamer densities and temperatures using Whole Sun Month coordinated data sets
Bagenal, F.; Fludra, A.; Gibson, S. E. +3 more
We model electron densities of the simplest, most symmetric solar minimum streamer structure observed during the Whole Sun Month (WSM) campaign, using coronal observations of both visible white light and extreme ultraviolet (EUV) emission. Using white light data from the SOHO/LASCO/C2 and HAO/Mauna Loa Mark 3 coronagraphs, we determine electron de…
Acceleration of the fast solar wind by the emergence of new magnetic flux
Schwadron, N. A.; Zurbuchen, T. H.; Fisk, L. A.
Recent observations have shown that small magnetic loops are continuously emerging within supergranules in the solar photosphere. The subsequent reconnection of this emerging flux with field lines which open into the corona should define the Poynting's vector and mass flux into the corona. These two quantities uniquely determine the final energy f…
Heating and cooling of protons by turbulence-driven ion cyclotron waves in the fast solar wind
Li, Xing; Habbal, Shadia R.; Hollweg, Joseph V. +1 more
The effects of parallel propagating nondispersive ion cyclotron waves on the solar wind plasma are investigated in an attempt to reproduce the observed proton temperature anisotropy, namely, Tp⊥>>Tp∥ in the inner corona and Tp⊥<Tp∥ at 1 AU. Low-frequency Alfvén waves are assumed to carry most of…
Three-dimensional propagation of coronal mass ejections in a structured solar wind flow 2. CME launched adjacent to the streamer belt
Pizzo, V. J.; Odstrčil, D.
A three-dimensional (3-D) numerical hydrodynamic model is used to investigate the evolution of coronal mass ejections (CMEs) launched at several heliographic positions into a tilted-dipole ambient solar wind (SW) flow, which is appropriate around solar activity minimum and declining phase. The CME is injected as an overpressured plasma cloud. Resu…
Physical properties of a coronal hole from a coronal diagnostic spectrometer, Mauna Loa Coronagraph, and LASCO observations during the Whole Sun Month
Fludra, A.; Gibson, S. E.; Biesecker, D. +2 more
Until recently [Guhathakurta and Fisher, 1998], inference of electron density distribution in the solar corona was limited by the field of view of white-light coronagraphs (typically out to 6 Rs). Now, for the first time we have a series of white-light coronagraphs (SOHO/LASCO) whose combined field of view extends from 1.1-30 Rs
Electron density and temperature of the lower solar corona
Del Zanna, G.; Fludra, A.; Bromage, B. J. I. +1 more
Off limb observations of the quiet Sun corona were made with the Coronal Diagnostic Spectrometer (CDS) on SOHO during the Whole Sun Month campaign in August 1996. Selected spectral lines in the Normal Incidence range were recorded up to 1.2 solar radii above the east and west limb and above the polar coronal holes. Intensities of the coronal lines…
The Elephant's Trunk: Spectroscopic diagnostics applied to SOHO/CDS observations of the August 1996 equatorial coronal hole
Del Zanna, G.; Bromage, B. J. I.
A large equatorial coronal hole, named the ``Elephant's Trunk,'' was observed by the coronal diagnostic spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO) during the last week of August 1996. Spatially averaged spectra within the hole and in neighboring quiet sun regions are analyzed and calibrated in intensity. Spectroscopi…
Filtration of interstellar hydrogen in the two-shock heliospheric interface: Inferences on the local interstellar cloud electron density
Gloeckler, George; Geiss, Johannes; Lallement, Rosine +3 more
The solar system is moving through the partially ionized local interstellar cloud (LIC). The ionized matter of the LIC interacts with the expanding solar wind forming the heliospheric interface. The neutral component (interstellar atoms) penetrates through the heliospheric interface into the heliosphere, where it is measured directly ``in situ'' a…
Radio signatures of a fast coronal mass ejection development on November 6, 1997
Schwenn, R.; Pick, M.; Vourlidas, A. +3 more
The Oporto radiospectrograph and the Nançay radioheliograph recorded a radio event on November 6, 1997, closely related in time with a flare on National Oceanic and Atmospheric Administration (NOAA) active region 8100. At the beginning of the event the radio sources are located on a rather small volume in the vicinity of the flare site. In a times…