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Three-Dimensional Reconstruction of Two Solar Coronal Mass Ejections Using the STEREO Spacecraft
Howard, Timothy A.; Tappin, S. James
Previous attempts to produce three-dimensional (3-D) reconstructions of coronal mass ejections (CMEs) have required either modeling efforts or comparisons with secondary associated eruptions near the solar surface. This is because coronagraphs are only able to produce sky-plane-projected images of CMEs and it has hence been impossible to overcome …
A Flare-Generated Shock during a Coronal Mass Ejection on 24 December 1996
Magdalenić, J.; Temmer, M.; Vršnak, B. +3 more
We present a multiwavelength study of the large-scale coronal disturbances associated with the CME - flare event recorded on 24 December 1996. The kinematics of the shock wave signature, the type II radio burst, is analyzed and compared with the flare evolution and the CME kinematics. We employ radio dynamic spectra, position of the Nançay Radiohe…
Observation and Modeling of the Solar-Cycle Variation of the Meridional Flow
Gizon, Laurent; Rempel, Matthias
We present independent observations of the solar-cycle variation of flows near the solar surface and at a depth of about 60 Mm, in the latitude range ± 45°. We show that the time-varying components of the meridional flow at these two depths have opposite sign, whereas the time-varying components of the zonal flow are in phase. This is in agreement…
Surface-Focused Seismic Holography of Sunspots: I. Observations
Birch, A. C.; Braun, D. C.
We present a comprehensive set of observations of the interaction of p-mode oscillations with sunspots using surface-focused seismic holography. Maps of travel-time shifts, relative to quiet-Sun travel times, are shown for incoming and outgoing p modes as well as their mean and difference. We compare results using phase-speed filters with results …
Multifractal Properties of Evolving Active Regions
Maguire, K.; Gallagher, P. T.; Young, C. A. +5 more
Magnetohydrodynamic turbulence is thought to be responsible for producing complex, multiscale magnetic field distributions in solar active regions. Here we explore the multiscale properties of a number of evolving active regions using magnetograms from the Michelson Doppler Imager (MDI) on the Solar and Heliospheric Observatory (SOHO). The multifr…
Stream Interactions and Interplanetary Coronal Mass Ejections at 5.3 AU near the Solar Ecliptic Plane
Luhmann, J. G.; Russell, C. T.; Jian, L. K. +2 more
We have performed a survey of the characteristics of two types of large spatial-scale solar-wind structures, stream interaction regions (SIRs), and interplanetary coronal mass ejections (ICMEs), near 5.3 AU, using solar-wind observations from Ulysses. Our study is confined to the three aphelion passes of Ulysses, and also within ± 10° of the solar…
Influence of Low-Degree High-Order p-Mode Splittings on the Solar Rotation Profile
Eff-Darwich, A.; Korzennik, S. G.; Jiménez-Reyes, S. J. +3 more
The solar rotation profile is well constrained down to about 0.25R⊙ thanks to the study of acoustic modes. Since the radius of the inner turning point of a resonant acoustic mode is inversely proportional to the ratio of its frequency to its degree, only the low-degree p modes reach the core. The higher the order of these modes, the dee…
Absorption Phenomena and a Probable Blast Wave in the 13 July 2004 Eruptive Event
Shibasaki, K.; Grechnev, V. V.; Chertok, I. M. +3 more
We present a case study of the 13 July 2004 solar event, in which disturbances caused by eruption of a filament from an active region embraced a quarter of the visible solar surface. Remarkable are the absorption phenomena observed in the SOHO/EIT 304 Å channel, which were also visible in the EIT 195 Å channel, in the Hα line, and even in total ra…
Structure and Evolution of Supergranulation from Local Helioseismology
Hirzberger, Johann; Solanki, Sami K.; Gizon, Laurent +1 more
Supergranulation is visible at the solar surface as a cellular pattern of horizontal outflows. Although it does not show a distinct intensity pattern, it manifests itself indirectly in, for example, the chromospheric network. Previous studies have reported significant differences in the inferred basic parameters of the supergranulation phenomenon.…
MHD Modeling of Coronal Large-Amplitude Waves Related to CME Lift-off
Vainio, R.; Pomoell, J.; Kissmann, R.
We have employed a two-dimensional magnetohydrodynamic simulation code to study mass motions and large-amplitude coronal waves related to the lift-off of a coronal mass ejection (CME). The eruption of the filament is achieved by an artificial force acting on the plasma inside the flux rope. By varying the magnitude of this force, the reaction of t…