We study in focus to the multi-wavelength radio spectra associated with quite strong CME events observed in the time interval of October 26–28, 2003. Using multi-wavelength observations recorded by WIND/WAVES experiment, Learmouth Spectrograph (Australian), PHOENIX-2 (Switzerland), Hiraiso (Japan), DAM/Nançay (France), Izmiran (Russia) and Huairou/NAOC (China), an analyzing of radio bursts was performed for the those events over a large coronal region across the microwave, the decimetric wavelength, the metric wavelength and even to much longer wavelength. The composite spectra indicate there were many complicated structures of radio bursts, including type II bursts, type IV bursts, type III bursts, drifting pulsation structures (DPS) and many radio fine structures (FS).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We include gravity in a loss of equilibrium model for the initiation of coronal mass ejections (CMEs). We examine equilibria for both normal and inverse polarity and neglect the effects of current sheets. Although equilibria exist for normal polarities, in the absence of current sheets, the equilibria are unstable to horizontal perturbations. For the inverse polarity configuration, we find that gravity generally has a negligible effect if the magnetic field is strong ($>$50 G) but that it can have a significant effect if the magnetic field is weak. Specifically, if the characteristic magnetic field is less than about 6 G, no eruption occurs if the CME mass is on the order of 2 $\times 10^{16}$ gm.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

An analytical method is used to model a magnetic field distribution in the vicinity of a large interplanetary or solar flux rope. The field is a sum of the pre-existing one and an additional current-free part. An example using real data is shown.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

After a brief overview of solar energetic particle (SEP) emission from coronal mass ejection (CME) shocks, we turn to a discussion of their transport and acceleration. The high energy SEP are accelerated near the Sun, and because of their well-known source location, their transport can be modeled quantitatively to obtain precise information on the injection function (number of particles emitted vs. time), including a determination of the onset time to within 1 min. For certain events, transport modeling also indicates magnetic topology with mirroring or closed field loops. Important progress has also been made on the transport of low energy SEP from very strong events, which can display exhibit interesting saturation effects and compositional variations. The acceleration of SEP by CME-driven shocks in the interplanetary medium is attributed to diffusive shock acceleration, but the spectrum of SEP production is typically modeled empirically. Recent progress has largely focused on using detailed composition measurements to determine fractionation effects of shock acceleration and even to clarify the nature of the seed population. In particular, there are many indications that the seed population is suprathermal (pre-energized) and the injection problem is not relevant to acceleration at interplanetary CME-driven shocks. We argue that the finite time available for shock acceleration provides the best explanation of the high-energy rollover.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We have studied the magnetic helicity transport rate and the current helicity for solar active region (AR) NOAA 10488 and find a complex relationship between them. We further extend this study to a statistical one, and find that 33 among the selected 57 ARs show opposite sign for the two parameter.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

A class of large-scale magnetic compositions have been identified to be CME-prolific, which is characterized by a huge unipolar sunspot appearing in a large-scale extended bipolar region in synoptic magnetic charts. To understand the CMEs' origin and the nature of flux appearance, we scrutinize the long time-sequence of MDI magnetograms of high-resolution mode for super active region AR9236. Two types of magnetic features are clearly identified. They are moving magnetic features (MMFs) emanated radially from the penumbral boundary and emerging flux regions (EFRs) whose growing opposite polarities rotate out from the inner boundary of sunspot moat along helical paths in opposite directions. The interaction between the MMFs and EFRs often creates multi-fold magnetic neutral lines where the flare/CMEs initiated.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The very active RS CVn-type star UX Ari was observed using high-resolution echelle spectrograph attached to the 2.16m telescope of Xinglong station in Nov.-Dec. 2001 and Dec. 2002. By means of synthetic spectral subtraction method, the information about chromospheric activity of the system was obtained through several chromospheric activity indicators HeI D$_3$, NaI D$_1$D$_2$, H$_{\alpha}$, and CaII IRT lines. Based on the analysis for these activity indicators, we found that the chromospheric activity of UX Ari showed obvious orbital modulation phenomenon, and the favorite active longitudes were around the quadratures of the binary system. During the two observing runs, hot plage and very strong optical flare events were detected, which were always happened around the favorite active longitudes of the system. Moreover, they were linked with the photospheric starspots in spatial structure, and appeared just above the main starspots.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present the observational results of the solar bursts on the band of 1-80 GHz (NORH) associated with both a CME and a flare on Oct. 26 2003. This event shows two parts of radio bursts in the time profile. The first part is associated with an X1.2 flare. However, the following part seams related to both the flare and the CME, as the radio emission is enhanced while the ${\rm H}\alpha$ is decreasing. Thus, these two parts of radio bursts may originate from different physical processes, i.e., flare and CME shock. A primary study is performed on the difference between this two parts.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

On acceleration of relativistic electrons by any means, the coherent pinch effect brings the relativistic electrons together. The inclusion of a suitable number of positive ions, preferentially heavy ions would stabilize the beam. The heavy trapped nuclei would have to go with the electrons, thus acquire relativistic speeds. The electron beam may be divided into small bunches. This mechanism can accelerate positive nuclei to GeV and TeV energies during solar flares, stellar and galactic high energy events. During the acceleration of 1000 GeV electron bunches, the energy gained by trapped positive nuclei is estimated to reach 10$^{15}$ eV per nucleon. Higher energies can be achieved by head on collision as the energy gained by the target nucleus is proportional to $\gamma^{2},$ however fission reactions and very high energy gamma rays may occur. The principle of this mechanism is applied in electron-ring accelerators.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

In this presentation we determine the source regions of CMEs that were observed with SoHO/LASCO during times of solar activity maximum (Feb./Mar. 2000) and during the declining phase of the solar cycle (Nov./Dec. 2002). The CMEs were traced back onto the disk and EIT EUV images were used for identifying the sources. With the help of MDI synoptic magnetograms we follow the evolution of the photospheric magnetic flux about 24h before and 12h after the event. We find that about 87% of the identified CME source regions show small–scale flux changes before the event, usually flux emergence and/or flux disappearance. In 13% of the cases we find no signature of photospheric flux changes.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Using the list of CMEs observed by SOHO/LASCO, we compile a daily CME counts from January 1996 to December 2003. Cross-correlations between the CME counts and other three solar activity indices, i.e., flare index, sunspot number, and photospheric magnetic flux, are examined in both real and Fourier spaces. We find that correlations are all significant in real space, but only photospheric magnetic flux has good correlation with CME counts in Fourier space. Typical periods of CME occurrence are presented and discussed.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Magnetic clouds are extended and magnetized plasma structures that travel from the Sun toward the outer heliosphere, carrying an important amount of magnetic helicity. The magnetic helicity quantifies several aspects of a given magnetic structure, such as the twist, kink, and the number of knots between magnetic field lines, the linking between magnetic flux tubes, etc. Since the helicity is practically conserved in the solar atmosphere and the heliosphere, it is a useful quantity to compare the physical properties of magnetic clouds to those of their solar source regions. In this work we describe a method that, assuming a cylindrical geometry for the magnetic cloud structures, allows us to calculate their helicity (per unit length) content directly from the observed magnetic field values. We apply the method to a set of 20 magnetic clouds observed by the WIND spacecraft. To test its reliability we compare our results with the helicity computed using a linear force-free field model under cylindrical geometry (i.e. Lundquist's solution).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

A complex solar radio burst was observed on 19 October 2001 with the spectrometers of NAOC (National Astronomical Observatory of China) and Nobeyama Radioheliograph (NoRH). Basing on the analysis of brightness temperature spectra of radio sources and various fine spectral structures, we get a diagnosis of magnetic field of radio active region.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The results of solar microwave observations in the Radio Astronomical Observatory NIRFI “Zimenki” are examined. Data analysis shows the presence of periodic component, that arose prior to burst connected to CMEs onset, and its absence after burst. Obtained data are compared with the dynamics of the development of activity on the solar disk. Results can be considered as the illustration of the dynamics of wave motions in the periods of flare activity.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Why CMEs erupt is a major outstanding puzzle of solar physics. Signatures observable at the earliest stages of eruption onset may hold precious clues about the onset mechanism. We summarize and discuss observations from SOHO/EIT in EUV and from Yohkoh/SXT in soft X-rays of the pre-eruption and eruption phases of three CME expulsions, along with the eruptions' magnetic setting inferred from SOHO/MDI magnetograms. Our events involve clearly-observable filament eruptions and multiple neutral lines, and we use the magnetic settings and motions of the filaments to help infer the geometry and behavior of the associated erupting magnetic fields. Pre-eruption and early-eruption signatures include a relatively slow filament rise prior to eruption, and intensity dimmings and brightenings, both in the immediate neighborhood of the “core” (location of greatest magnetic shear) of the erupting fields and at locations remote from the core. These signatures and their relative timings place observational constraints on eruption mechanisms; our recent work has focused on implications for the so-called “tether cutting” and “breakout” models, but the same observational constraints are applicable to any model.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We summarize results of our recent studies of CME-associated EUV dimmings and coronal waves by ‘derotated’ fixed-difference SOHO/EIT heliograms at 195 Å with 12-min intervals and at 171, 195, 284, 304 Å with 6-h intervals. Correctness of the derotated fixed-difference technique is confirmed by the consideration of the Bastille Day 2000 event. We also demonstrate that long narrow channeled dimmings and anisotropic coronal waves are typical of the complex global solar magnetosphere near the solar cycle maximum. Homology of large-scale dimmings and coronal waves takes place in a series of recurrent eruptive events. Along with dimmings coinciding entirely or partially in all four EIT bands, there exist dimmings that appear different, mainly in the transition-region line of 304 Å and high-temperature coronal line of 284 Å.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Shocks driven by energetic coronal mass ejections and other interplanetary transients are mainly responsible for large disturbances in geomagnetic field of Earth and play a key role in producing a geomagnetic storm or substorm. A geomagnetic storm is a global disturbance in Earth's magnetic field usually occurred due to abnormal conditions in the IMF and solar wind plasma emissions caused by various solar phenomenon. Identifying intense geomagnetic storms with Dst decrease more than/or equal to 300 nT occurred during 1981-2001, a correlative study has been performed to analyze the associated solar and interplanetary causes of these 09 events using solar wind plasma, IMF and solar geophysical data. It is observed statistically that 55% storms have occurred during solar maximum and 45% occurred during minimum phase of solar cycles. Further, study reveals that 77% intense storms are associated with CMEs, which confirms earlier findings.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Solar energetic particle (SEP) fluxes measured by the ULYSSES (ULS)/HI-SCALE experiment during its second polar orbit as well as by the identical ACE/EPAM experiment at 1 AU are utilized as diagnostics of the large-scale structure and topology of the Interplanetary Magnetic Field (IMF) embedded within Interplanetary Coronal Mass Ejections (ICMEs). Survey results are also reported.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Using multi-spectral data, we estimate plasma parameters in the post-eruptive arcade observed on October 22, 2001 at 100 Mm above the limb: the temperature is 6 MK and the plasma density is $(5-9) \cdot 10^9$ cm$^{-3}$. We state a problem of the long-term equilibrium of the hot top of the arcade high in the corona: either the magnetic field surrounding the arcade well exceeds that one extrapolated in the potential approximation, or $\beta > 1$ both inside and outside the arcade. A downflow observed in soft X-rays can contribute to the equilibrium.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

By means of multiwavelength data, we study the eruptions of two filaments and the relationship between the first filament eruption and a subsequent CME. The main results are: (1) The disturbances of the two filaments showed different features, indicating that their eruptive mechanisms were possibly different. (2) A subsequent CME was well correlated with the first eruption in both time and space.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html