Search Publications
Quantitative comparison of methods for predicting the arrival of coronal mass ejections at Earth based on multiview imaging
Vourlidas, A.; Colaninno, R. C.; Wu, C. C.
We investigate the performance of six methods for predicting the coronal mass ejection (CME) time of arrival (ToA) and velocity at Earth using a sample of nine Earth-impacting CMEs between March 2010 and June 2011. The CMEs were tracked continuously from the Sun to near Earth in multiviewpoint imaging data from STEREO Sun-Earth Connection Coronal …
Full halo coronal mass ejections: Do we need to correct the projection effect in terms of velocity?
Wang, Yuming; Shen, Chenglong; Wang, S. +3 more
The projection effect is one of the biggest obstacles in learning the real properties of coronal mass ejections (CMEs) and forecasting their geoeffectiveness. To evaluate the projection effect, 86 full halo CMEs (FHCMEs) listed in the Coordinated Data Analysis Workshop CME catalog from 1 March 2007 to 31 May 2012 are investigated. By applying the …
On the application of ensemble modeling techniques to improve ambient solar wind models
Riley, Pete; Linker, Jon A.; Mikić, Zoran
Ensemble modeling is a method of prediction based on the use of a representative sample of possible future states. Global models of the solar corona and inner heliosphere are now maturing to the point of becoming predictive tools; thus, it is both meaningful and necessary to quantitatively assess their uncertainty and limitations. In this study, w…
UVCS/SOHO catalog of coronal mass ejections from 1996 to 2005: Spectroscopic proprieties
Raymond, J. C.; Ciaravella, A.; Giordano, S. +2 more
Ultraviolet spectra of the extended solar corona have been routinely obtained by SOHO/UltraViolet Coronagraph Spectrometer (UVCS) since 1996. Sudden variations of spectral parameters are mainly due to the detection of coronal mass ejections (CMEs) crossing the instrumental slit. We present a catalog of CME ultraviolet spectra based upon a systemat…
Heliolatitudinal and time variations of the solar wind mass flux: Inferences from the backscattered solar Lyman-alpha intensity maps
Quemerais, E.; Sokół, J. M.; Katushkina, O. A. +1 more
Recently Sokół et al. (2012) have presented a reconstruction of heliolatitudinal and time variations of the solar wind speed and density. Method of the reconstruction was based on the following: (i) measurements of the interplanetary scintillations, (ii) OMNI-2 solar wind data in the ecliptic plane, and (iii) Ulysses solar wind data out of the ecl…
An MHD simulation model of time-dependent global solar corona with temporally varying solar-surface magnetic field maps
Hayashi, K.
We present a model of a time-dependent three-dimensional magnetohydrodynamics simulation of the sub-Alfvenic solar corona and super-Alfvenic solar wind with temporally varying solar-surface boundary magnetic field data. To (i) accommodate observational data with a somewhat arbitrarily evolving solar photospheric magnetic field as the boundary valu…
Interplanetary and geomagnetic consequences of 5 January 2005 CMEs associated with eruptive filaments
Möstl, Christian; Srivastava, Nandita; Chakrabarty, D. +2 more
On 5 January 2005, SoHO/LASCO observed the launch of two successive coronal mass ejections (CMEs) associated with the filament (active region and quiescent) structures. The eruptions resulted in two distinct magnetic clouds whose embedded flux-rope topology is modeled by the Grad-Shafranov (G-S) reconstruction technique. Filament plasma remnants i…
Earth's collision with a solar filament on 21 January 2005: Overview
Escoubet, C. P.; Tsurutani, B. T.; Lepri, S. T. +5 more
21 January 2005, one of the fastest interplanetary coronal mass ejections (ICME) of solar cycle 23, containing exceptionally dense plasma directly behind the sheath, hit the magnetosphere. We show from charge-state analysis that this material was a piece of the erupting solar filament and further, based on comparisons to the simulation of a fast C…
Observational study of the cooling behavior of interstellar helium pickup ions in the inner heliosphere
Bochsler, Peter; Gloeckler, George; Isenberg, Philip A. +4 more
velocity distribution of interstellar pickup ions (PUIs) has typically been described as evolving through fast pitch angle scattering followed by adiabatic cooling while being transported radially outward with the solar wind. In combination, the ionization rate, which controls the radial profile of the interstellar neutrals, and the cooling proces…
Association of solar wind proton flux extremes with pseudostreamers
Zhao, L.; Fisk, L. A.; Gibson, S. E.
We investigate the characteristics and solar origins of a subpopulation of the solar wind that possesses extreme values of proton flux. Ulysses observations including solar wind magnetic flux, proton flux, number density and velocity, and ionic composition are examined in this study. We find that the departures of solar wind proton flux from its c…