Search Publications
A statistical study on the relationship between surface field variation and CME initiation
Zhang, H. Q.; Zhang, Y.; Zhang, M.
In order to understand whether coronal mass ejections (CMEs) can be related to changes in the longitudinal photospheric magnetic field, we study 51 CME-producing active regions (ARs) which are associated with 77 halo CMEs during the period of their solar disk passage. We look at the magnetic field evolution during the short-term of 12 h before CME…
Signatures of magnetic reconnection in solar radio observations?
Aurass, Henry
Magnetic reconnection occurs during eruptive processes (flares, CMEs) in the solar corona. This leads to a change of magnetic connectivity. Nonthermal electrons propagate along the coronal magnetic field thereby exciting dm- and m-wave radio burst emission after acceleration during reconnection or other energy release processes in heights of some …
The relationship between inductive electric field and flares
Liu, J. H.; Zhang, H. Q.
We observationally deduce the inductive electric field in the photosphere for the first time from the horizontal velocities computed by local correlation tracking (LCT) technique and the vector magnetic fields derived from vector magnetograms. We study the relationship between E and powerful flares (X-class) of four active regions (ARs): NOAA 1072…
Relative fluxes of shock and prompt peaks in SEP event time profiles
Luhmann, J. G.; Mann, Adam
Peak fluxes are an important property of gradual solar energetic particle (SEP) event time profiles from both astro/heliophysical and applications perspectives. However, the peak flux in an event may occur at the event onset, or at the time of the interplanetary shock arrival (the ESP or energetic storm particles). This makes an important differen…
Magnetic coupling of the Sun Earth system The view from STEREO
Culhane, J. L.; Matthews, S. A.
The STEREO mission, launched on October 25 2006, will provide the first stereoscopic view of the Sun and its magnetic environment. A suite of identical instruments on two continuously separating spacecraft will monitor the onset of solar eruptive phenomena, and track them as the shocks and ejected material propagate through the interplanetary medi…
The multi-wavelength study of the effect of energetic particle beams on the chromospheric emission in the 25th July 2004 solar flare
Zharkova, V. V.; Kashapova, L. K.; Chornogor, S. N. +1 more
We present the multi-wavelength study of short-term variations of Hα line emission located in multiple kernels on the both sides from magnetic neutral line in the 25th July 2004 solar flare observed by VTT (Tenerife). The HXR and Hα emission in the kernels 1 and 3 is close spatially and temporally while in kernels 4 and 7 there is only delayed Hα …
Observed flux density enhancement at submillimeter wavelengths during an X-class flare
Mandrini, C. H.; Giménez de Castro, C. G.; Cristiani, G. +4 more
We analyse the 30 October, 2004, X1.2/SF solar event that occurred in AR 10691 (N13 W18) at around 11:44 UT. Observations at 212 and 405 GHz of the Solar Submillimeter Telescope (SST), with high time resolution (5 ms), show an intense impulsive burst followed by a long-lasting thermal phase. EUV images from the Extreme Ultraviolet Imaging Telescop…
On anticorrelation of number of coronal bright points with sunspot number during 1996 2006
Karachik, Nina V.; Pevtsov, Alexei A.; Sattarov, Isroil +1 more
Using full disk SOHO/EIT data from 1996 to 2006, we study latitudinal distribution of coronal bright points over a period of one solar cycle. We confirm the presence of two distinct types of coronal bright points, and find that the number of "quiet corona" bright points in high latitudes anticorrelate with solar activity as defined by the sunspot …
Risk of dust particle impacts during the Rosetta asteroid fly-bys
Rossi, A.; Fulchignoni, M.
On its course to the comet 67P/Churyumov-Gerasimenko, Rosetta will fly past two main belt asteroids: 2867 Steins and 21 Lutetia. In order to explore the possible risks of impact between the Rosetta probe and particles orbiting 21 Lutetia, the asteroid's dynamical environment is studied. Stable retrograde, nearly equatorial orbits, for small partic…
Several problems in measuring solar vector magnetic fields
Zhang, H. Q.; Ruan, G. P.; Su, J. T. +1 more
Observations of solar photosphere vector magnetic fields with a magnetograph are subjected to many difficulties, such as azimuth ambiguity, magnetic saturation, Faraday rotation, scattered light, polarization crosstalk, and wavelength shift, and so on. Among these issues, Faraday rotation and scattered light are obvious in local-region vector magn…