Search Publications
A Statistical Study of Distant Consequences of Large Solar Energetic Events
Schrijver, Carolus J.; Higgins, Paul A.
Large solar flares and eruptions may influence remote regions through perturbations in the outer-atmospheric magnetic field, leading to causally related events outside of the primary or triggering eruptions that are referred to as "sympathetic events". We quantify the occurrence of sympathetic events using the full-disk observations by the Atmosph…
High-Resolution Observations of a Flux Rope with the Interface Region Imaging Spectrograph
Li, Ting; Zhang, Jun
We report the observations of a flux rope at transition region temperatures with the Interface Region Imaging Spectrograph (IRIS) on 30 August 2014. Initially, magnetic flux cancellation continually took place and a filament was activated. Then the bright material from the filament moved southward and tracked out several fine structures. These fin…
Fine Structure of Metric Type IV Radio Bursts Observed with the ARTEMIS-IV Radio-Spectrograph: Association with Flares and Coronal Mass Ejections
Hillaris, A.; Preka-Papadema, P.; Moussas, X. +5 more
Fine structures embedded in type IV burst continua may be used as diagnostics of the magnetic-field restructuring and the corresponding energy release associated with the low-corona development of flare or coronal mass ejection (CME) events. A catalog of 36 type IV bursts observed with the SAO receiver of the ARTEMIS-IV solar radio-spectrograph in…
Wave-like Formation of Hot Loop Arcades
Shestov, S.; Kuzin, S.; Zimovets, I. +2 more
We present observations of hot arcades made with the Mg XII spectroheliograph onboard the CORONAS-F mission, which provides monochromatic images of hot plasma in the Mg XII 8.42 Å resonance line. The arcades were observed to form above the polarity inversion line between active regions NOAA 09847 and 09848 at four successive episodes: at 09:18, 14…
Kinematics of ICMEs/Shocks: Blast Wave Reconstruction Using Type-II Emissions
Aguilar-Rodriguez, E.; Corona-Romero, P.; Gonzalez-Esparza, J. A. +2 more
We present a physical methodology for reconstructing the trajectory of interplanetary shocks using Type-II radio emission data. This technique calculates the shock trajectory assuming that the disturbance propagates as a blast wave in the interplanetary medium. We applied this blast-wave reconstruction (BWR) technique to analyze eight fast Earth-d…
Mid-Term Quasi-Periodicities and Solar Cycle Variation of the White-Light Corona from 18.5 Years (1996.0 - 2014.5) of LASCO Observations
Llebaria, A.; Lamy, P.; Barlyaeva, T.
We report on the analysis of the temporal evolution of the solar corona based on 18.5 years (1996.0 - 2014.5) of white-light observations with the SOHO/LASCO-C2 coronagraph. This evolution is quantified by generating spatially integrated values of the K-corona radiance, first globally, then in latitudinal sectors. The analysis considers time serie…
Fine and Superfine Structure of the Decameter-Hectometer Type II Burst on 7 June 2011
Panchenko, M.; Poedts, S.; Konovalenko, A. A. +4 more
The characteristics of a type II burst with a herringbone structure observed both with ground-based radio telescopes (UTR-2 and URAN-2) and space-borne spectrometers (STEREO-A and B) are discussed. The burst was recorded on 7 June 2011 in the frequency band 3 - 33 MHz. It was characterized by extremely rich fine structure. Statistical analysis of …
Dynamics of Microwave Sources Associated with the Neutral Line and the Magnetic-Field Parameters of Sunspots as a Factor in Predicting Large Flares
Abramov-Maximov, V. E.; Borovik, V. N.; Opeikina, L. V. +1 more
We studied the evolution of five active regions (ARs) where strong X-class flares occurred in 2011 - 2012 (NOAA ARs 11158, 11166, 11263, 11283 and 11520). Our study focuses on the pre-flare phase of these ARs (during a few days before the flare) to reveal features in the microwave radiation and magnetic-field characteristics of the ARs that indica…
Ensemble Modeling of Successive Halo CMEs: A Case Study
Arge, C. N.; Odstrcil, D.; Pizzo, V. +3 more
The Wang-Sheeley-Arge (WSA)-Enlil cone modeling system is used for making routine arrival-time forecasts of Earth-directed halo coronal mass ejections (CMEs), since they typically produce the most geoeffective events. A major objective of this work is to better understand the sensitivity of the WSA-Enlil modeling results to input model parameters …
The Properties of the Tilts of Bipolar Solar Regions
Tlatov, A.; Illarionov, E.; Sokoloff, D.
We investigate various properties associated with the tilt of isolated magnetic bipoles in magnetograms taken at the solar surface. We show that bipoles can be divided into two groups that have tilts of opposite signs, and reveal similar properties with respect to bipole area, flux, and bipolar moment. Detailed comparison of these physical quantit…