Search Publications
Spatio-temporal Dynamics of Sources of Hard X-Ray Pulsations in Solar Flares
Zimovets, I. V.; Struminsky, A. B.; Kuznetsov, S. A. +1 more
We present a systematic analysis of the spatio-temporal evolution of sources of hard X-ray (HXR) pulsations in solar flares. We concentrate on disk flares whose impulsive phases are accompanied by a series of more than three successive peaks (pulsations) of HXR emission detected in the RHESSI 50 - 100 keV energy channel with a four-second time cad…
Coronal Hole and Solar Global Magnetic Field Evolution in 1976 - 2012
Bilenko, Irina A.; Tavastsherna, Ksenia S.
We study the spatial-temporal evolution of a coronal hole and compare it with that of the solar global magnetic field in Cycles 21 - 23 (1976 - 2012). We also analyze the latitude-longitude distribution dynamics of coronal holes and the regularities in the global magnetic field associated with the solar polar field reversal. Polar and non-polar co…
A Tiny Eruptive Filament as a Flux-Rope Progenitor and Driver of a Large-Scale CME and Wave
Grechnev, V. V.; Fainshtein, V. G.; Kochanov, A. A. +5 more
A solar eruptive event SOL2010-06-13 observed with the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) has been extensively discussed in the contexts of the CME development and an associated extreme-ultraviolet (EUV) wave-like transient in terms of a shock driven by the apparent CME rim. Continuing the analysis of this e…
A Comparison of Global Magnetic Field Skeletons and Active-Region Upflows
Culhane, J. L.; Brooks, D. H.; Harra, L. K. +2 more
Plasma upflows have been detected in active regions using Doppler velocity maps. The origin and nature of these upflows is not well known with many of their characteristics determined from the examination of single events. In particular, some studies suggest these upflows occur along open field lines and, hence, are linked to sources of the solar …
Sources of the Slow Solar Wind During the Solar Cycle 23/24 Minimum
Madjarska, M. S.; Kilpua, E. K. J.; Wiegelmann, T. +4 more
We investigate the characteristics and the sources of the slow (<450 kms−1) solar wind during the four years (2006 - 2009) of low solar activity between Solar Cycles 23 and 24. We used a comprehensive set of in-situ observations in the near-Earth solar wind (Wind and ACE) and removed the periods when large-scale interplanetary corona…
Two Exceptions in the Large SEP Events of Solar Cycles 23 and 24
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We discuss our findings from a survey of all large solar energetic particle (SEP) events of Solar Cycles 23 and 24, i.e. the SEP events where the intensity of > 10 MeV protons observed by GOES was > 10 pfu. In our previous work (Gopalswamy et al. in Geophys. Res. Lett. 41, 2673, 2014) we suggested that ground level enhancements (GLEs) in Cyc…
Properties of Magnetic Tongues over a Solar Cycle
Démoulin, Pascal; Mandrini, Cristina H.; López Fuentes, Marcelo +1 more
The photospheric spatial distribution of the main magnetic polarities of bipolar active regions (ARs) present during their emergence deformations are known as magnetic tongues. They are attributed to the presence of twist in the toroidal magnetic-flux tubes that form the ARs. The aim of this article is to study the twist of newly emerged ARs from …
Simultaneous Near-Sun Observations of a Moving Type IV Radio Burst and the Associated White-Light Coronal Mass Ejection
Ramesh, R.; Kathiravan, C.; Wang, T. J. +1 more
We present rare contemporaneous low-frequency (<100 MHz) imaging, spectral, and polarimetric observations of a moving type IV radio burst that had close spatio-temporal association with a white-light coronal mass ejection (CME) near the Sun. We estimate the electron density near the burst region from white-light coronagraph polarized brightness…
An Intense Flare-CME Event in 2015: Propagation and Interaction Effects Between the Sun and Earth's Orbit
Manoharan, P. K.; Johri, Abhishek
We report the interplanetary effects of a fast coronal mass ejection (CME) associated with the intense X2.7 flare that occurred on 05 May 2015. The near-Sun signatures of the CME at low-coronal heights [<2 R⊙] are obtained from the EUV images at 171 Å and metric radio observations. The intensity and duration of the CME-driven radio b…
Moreton and EUV Waves Associated with an X1.0 Flare and CME Ejection
Long, David M.; Mandrini, Cristina H.; Cremades, Hebe +3 more
A Moreton wave was detected in active region (AR) 12017 on 29 March 2014 with very high cadence with the H-Alpha Solar Telescope for Argentina (HASTA) in association with an X1.0 flare (SOL2014-03-29T17:48). Several other phenomena took place in connection with this event, such as low-coronal waves and a coronal mass ejection (CME). We analyze the…