Search Publications
A Multiple Flare Scenario where the Classic Long-Duration Flare Was Not the Source of a CME
Mandrini, C. H.; van Driel-Gesztelyi, L.; Culhane, J. L. +6 more
A series of flares (GOES class M, M and C) and a CME were observed in close succession on 20 January 2004 in NOAA 10540. Radio observations, which took the form of types II, III and N bursts, were associated with these events. We use the combined observations from TRACE, EIT, Hα images from Kwasan, MDI magnetograms and GOES to understand the compl…
Magnetic Stereoscopy of Coronal Loops in NOAA 8891
Feng, L.; Inhester, B.; Gan, W. Q. +3 more
The Solar TErrestrial RElations Observatory (STEREO) requires powerful tools for the three-dimensional (3D) reconstruction of the solar corona. Here we test such a program with data from SOHO and TRACE. By taking advantage of solar rotation, a newly developed stereoscopy tool for the reconstruction of coronal loops is applied to the solar active r…
Magnetic Solitons: Unified Mechanism for Moving Magnetic Features
Ryutova, M.; Hagenaar, H.
In a highly dynamic environment with sources and sinks of energy, flux tubes do not in general obey local conservation laws, nor do the ensembles of flux tubes that exhibit collective phenomena. We use the approach of energetically open dissipative systems to study nonlinear waves in flux tubes and their role in the dynamics of the overlying atmos…
Width of Radio-Loud and Radio-Quiet CMEs
Gopalswamy, N.; Michalek, G.; Xie, H.
In the present paper we report on the difference in angular sizes between radio-loud and radio-quiet CMEs. For this purpose we compiled these two samples of events using Wind/WAVES and SOHO/LASCO observations obtained during 1996 - 2005. We show that the radio-loud CMEs are almost twice as wide as the radio-quiet CMEs (considering expanding parts …
Quasi-Simultaneous Flux Emergence in the Events of October November 2003
Wang, Yuming; Wang, Jingxiu; Zhang, Yuzong +1 more
From late October to the beginning of November 2003, a series of intense solar eruptive events took place on the Sun. More than six active regions (ARs), including three large ARs (NOAA numbers AR 10484, AR 10486, and AR 10488), were involved in the activity. Among the six ARs, four of them bear obviously quasi-simultaneous emergence of magnetic f…
On Solar Intermediate Drift Radio Bursts at Decimeter and Meter Wavelength
Mann, G.; Karlický, M.; Aurass, H. +2 more
Fiber - or intermediate drift - bursts are a continuum fine structure in some complex solar radio events. We present the analysis of such bursts in the X17 flare on 28 Oct. 2003. Based on the whistler wave model of fiber bursts we derive the 3D magnetic field structures that carry the radio sources in different stages of the event and obtain insig…
Fine Structure of Solar Radio Bursts Observed at Decametric and Hectometric Waves
Kaiser, M. L.; Bougeret, J. -L.; Chernov, G. P. +2 more
The analysis of WIND/WAVES RAD2 spectra with fine structure in the form of different fibers in 14 events covering 1997 - 2005 is carried out. A splitting of broad bands of the interplanetary (IP) type II bursts into narrow band fibers of different duration is observed. The instantaneous-frequency bandwidth of fibers is stable: 200 - 300 kHz for sl…
Prediction of Space Weather Using an Asymmetric Cone Model for Halo CMEs
Gopalswamy, N.; Michalek, G.; Yashiro, S.
Halo coronal mass ejections (HCMEs) are responsible of the most severe geomagnetic storms. A prediction of their geoeffectiveness and travel time to Earth's vicinity is crucial to forecast space weather. Unfortunately, coronagraphic observations are subjected to projection effects and do not provide true characteristics of CMEs. Recently, Michalek…
The Ly α and Ly β Profiles in Solar Prominences and Prominence Fine Structure
Vial, J. -C.; Ajabshirizadeh, A.; Ebadi, H.
Ly α and Ly β line profiles in a solar prominence were observed with high spatial and spectral resolution with SOHO/SUMER. Within a 60-arcsec scan, we measure a very large variety of profiles: not only reversed and nonreversed profiles but also red-peaked and blue-peaked ones in both lines. Such a spatial variability is probably related to both th…
Microwave Type III-Like Bursts as Possible Signatures of Magnetic Reconnection
Yan, Y.; Grechnev, V. V.; Altyntsev, A. T. +1 more
Magnetic reconnection is commonly accepted to play a key role in flare energy release, but only poor information about the main characteristics of this process is available so far. An intrinsic feature of reconnection is plasma density enhancement in current sheets. A unique method to detect this effect is provided by analysis of drifting bursts, …