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1.
We analyze the relationship between the dynamics of the coronal mass ejection (CME) of 15 May 2001 and the energy release in the associated flare. The flare took place behind the east limb and was disclosed by a growing system of hot soft X-ray (SXR) loops that appeared from behind the limb around the onset of the rapid acceleration of the CME. The highly correlated behavior of the SXR light-curve derivative and the time profile of the CME acceleration reveals an intrinsic relationship between the CME dynamics and the flare energy release. Furthermore, we found that the CME acceleration peak occurs simultaneously with the fastest growth (100 km s-1) of X-ray loops, indicating that the reconnection plays an essential role in the eruption. Inspecting the CME/flare morphology we recognized in the Yohkoh-SXT images an oval feature that formed within the rising structure at the onset of the rapid acceleration phase, simultaneously with the appearance of the X-ray loops. The eruptive prominence was imbedded within the lower half of the oval, suggestive of a flux-rope/prominence magnetic configuration. We interpret the observed morphological evolution in terms of a reconnection process in the current sheet that presumably formed below the erupting flux-rope at the onset of the CME acceleration. Measurements of the tip-height of the cusped X-ray loop system and the height of the lower edge of the oval, enable us to trace the stretching of the current sheet. The initial distance between the oval and the loops amounted to 35 – 40 Mm. In about 1 h the inferred length of the current sheet increased to 150 – 200 Mm, which corresponds to a mean elongation speed of 35 – 45 km s-1. The results are discussed in the framework of CME models that include the magnetic reconnection below the erupting flux-rope.  相似文献   

2.
We study the initiation and development of the limb coronal mass ejection (CME) of 15 May 2001, utilizing observations from Mauna Loa Solar Observatory (MLSO), the Solar and Heliospheric Observatory (SOHO), and Yohkoh. The pre-eruption images in various spectral channels show a quiescent prominence imbedded in the coronal void, being overlaid by the coronal arch. After the onset of rapid acceleration, this three-element structure preserved its integrity and appeared in the MLSO MK-IV coronagraph field of view as the three-part CME structure (the frontal rim, the cavity, and the prominence) and continued its motion through the field of view of the SOHO/LASCO coronagraphs up to 30 solar radii. Such observational coverage allows us to measure the relative kinematics of the three-part structure from the very beginning up to the late phases of the eruption. The leading edge and the prominence accelerated simultaneously: the rapid acceleration of the frontal rim and the prominence started at approximately the same time, the prominence perhaps being slightly delayed (4 – 6 min). The leading edge achieved the maximum acceleration amax 600 ± 150 m s–2 at a heliocentric distance 2.4 –2.5 solar radii, whereas the prominence reached amax 380± 50 m s–2, almost simultaneously with the leading edge. Such a distinct synchronization of different parts of the CME provides clear evidence that the entire magnetic arcade, including the prominence, erupts as an entity, showing a kind of self-similar expansion. The CME attained a maximum velocity of vmax 1200 km s–1 at approximately the same time as the peak of the associated soft X-ray flare. Beyond about 10 solar radii, the leading edge of the CME started to decelerate at a–20 m s–2, most likely due to the aerodynamic drag. The deceleration of the prominence was delayed for 10 –30 min, which is attributed to its larger inertia.  相似文献   

3.
The eruption of a large quiescent prominence on 17 August 2013 and an associated coronal mass ejection (CME) were observed from different vantage points by the Solar Dynamics Observatory (SDO), the Solar-Terrestrial Relations Observatory (STEREO), and the Solar and Heliospheric Observatory (SOHO). Screening of the quiet Sun by the prominence produced an isolated negative microwave burst. We estimated the parameters of the erupting prominence from a radio absorption model and measured them from 304 Å images. The variations of the parameters as obtained by these two methods are similar and agree within a factor of two. The CME development was studied from the kinematics of the front and different components of the core and their structural changes. The results were verified using movies in which the CME expansion was compensated for according to the measured kinematics. We found that the CME mass (\(3.6 \times 10^{15}\mbox{ g}\)) was mainly supplied by the prominence (\(\approx 6 \times 10^{15}\mbox{ g}\)), while a considerable part drained back. The mass of the coronal-temperature component did not exceed \(10^{15}\mbox{ g}\). The CME was initiated by the erupting prominence, which constituted its core and remained active. The structural and kinematical changes started in the core and propagated outward. The CME structures continued to form during expansion, which did not become self-similar up to \(25~\mathrm{R}_{\odot }\). The aerodynamic drag was insignificant. The core formed during the CME rise to \(4~\mathrm{R}_{\odot }\) and possibly beyond. Some of its components were observed to straighten and stretch outward, indicating the transformation of tangled structures of the core into a simpler flux rope, which grew and filled the cavity as the CME expanded.  相似文献   

4.
We report observations by the Large Angle Spectrometric Coronagraph (LASCO) on the SOHO spacecraft of three coronal green-line transients that could be clearly associated with coronal mass ejections (CMEs) detected in Thomson-scattered white light. Two of these events, with speeds >25 km s-1, may be classified as ‘whip-like’ transients. They are associated with the core of the white-light CMEs, identified with erupting prominence material, rather than with the leading edge of the CMEs. The third green-line transient has a markedly different appearance and is more gradual than the other two, with a projected outward speed <10 km s-1. This event corresponds to the leading edge of a ‘streamer blowout’ type of CME. A dark void is left behind in the emission-line corona following each of the fast eruptions. Both fast emission-line transients start off as a loop structure rising up from close to the solar surface. We suggest that the driving mechanism for these events may be the emergence of new bipolar magnetic regions on the surface of the Sun, which destabilize the ambient corona and cause an eruption. The possible relationship of these events to recent X-ray observations of CMEs is briefly discussed. Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1004981125702  相似文献   

5.
We report on the occurrence of Hα dimming associated with a sigmoid eruption in a quiet-sun region on 14 August 2001. The coronal sigmoid in soft X-ray images from the Yohkoh Soft X-ray Telescope was located over an Hα filament channel. Its eruption was accompanied by a flare of GOES X-ray class C2.3 and possibly associated with a halo coronal mass ejection (CME) observed with the Large Angle and Spectroscopic Coronagraphs (LASCO) on board the Solar and Heliospheric Observatory (SOHO). During the eruption, coronal bipolar double dimming took place at the regions with opposite magnetic polarities around the two sigmoid ends, but the underlying chromospheric channel did not show observable changes corresponding to the coronal eruption. Different from the erupting coronal sigmoid itself, however, the coronal dimming had a detectable chromosphere counterpart, i.e., Hα dimming. By regarding the sigmoid as a coronal sign for a flux rope, these observations are explained in the framework of the flux rope model of CMEs. The flux rope is possibly deeply rooted in the chromosphere, and the coronal and Hα dimming regions mark its evacuated feet, through which the material is possibly fed to the halo CME.  相似文献   

6.
Jordan  Stuart  Garcia  Adriana  Bumba  Vaclav 《Solar physics》1997,173(2):359-376
A time series of K3 spectroheliograms taken at the Coimbra Observatory exhibits an erupting loop on the east limb on July 9, 1982 in active region NOAA 3804. The Goddard SMM Hard X-Ray Burst Spectrometer (HXRBS) observations taken during this period reveal a hard X-ray flare occurring just before the loop eruption is observed, and SMS-GOES soft X-ray observations reveal a strong long-duration event (LDE) following the impulsive phase of the flare. A Solwind coronagram exhibits a powerful coronal mass ejection (CME) associated with the erupting loop. H flare and prominence observations as well as centimeter and decimeter radio observations of the event are also reviewed. A large, north–south-oriented quiescent prominence reported within the upper part of the CME expansion region may play a role in the eruption as well. The spatial and temporal correlations among these observations are examined in the light of two different current models for prominence eruption and CME activation: (1) The CME is triggered by the observed hard X-ray impulsive flare. (2) The CME is not triggered by a flare, and the observed soft X-ray flare is an LDE due to reconnection within the CME bubble. It is concluded that this event is probably of a mixed type that combines characteristics of models (1) and (2). The July 9 event is then compared to three other energetic CME and flare eruptions associated with the same active-region complex, all occurring in the period July 9 through September 4, 1982. It is noted that these four energetic events coincide with the final evolutionary phase of a long-lasting active-region complex, which is discussed in a companion paper (Bumba, Garcia, and Jordan, 1997). The paper concludes by addressing the solar flare myth controversy in the light of this work.  相似文献   

7.
We study the correlation between near-Earth observations of interplanetary coronal mass ejections (ICMEs) detected by the Wind and ACE spacecrafts and their counterparts of coronal mass ejections (CMEs) observed near the Sun by the SOHO/LASCO coronagraph during 1996–2002. The results have been compared with an empirical model given by Gopalswamy, et al. (2000; 2001) to predict the 1-AU arrival time of CMEs. In this paper, we use an expected data set with a wider range with initial velocities than that considered in previous models. To improve the accuracy of the predicted arrival time, we divided the CME events into two groups according to their effective acceleration and deceleration. The results show that our model works well for events with a negative acceleration in the initial velocity range between 500 and 2500 km/s, while the model described by Gopalswamy is better for events with initial velocities near the solar wind velocity. Published in Russian in Astronomicheskii Vestnik, 2009, Vol. 43, No. 2, pp. 137–144. The text was translated by the authors.  相似文献   

8.
We intend to provide a comprehensive answer to the question on whether all Coronal Mass Ejections (CMEs) have flux rope structure. To achieve this, we present a synthesis of the LASCO CME observations over the last 16 years, assisted by 3D MHD simulations of the breakout model, EUV and coronagraphic observations from STEREO and SDO, and statistics from a revised LASCO CME database. We argue that the bright loop often seen as the CME leading edge is the result of pileup at the boundary of the erupting flux rope irrespective of whether a cavity or, more generally, a three-part CME can be identified. Based on our previous work on white light shock detection and supported by the MHD simulations, we identify a new type of morphology, the ‘two-front’ morphology. It consists of a faint front followed by diffuse emission and the bright loop-like CME leading edge. We show that the faint front is caused by density compression at a wave (or possibly shock) front driven by the CME. We also present highly detailed multi-wavelength EUV observations that clarify the relative positioning of the prominence at the bottom of a coronal cavity with a clear flux rope structure. Finally, we visually check the full LASCO CME database for flux rope structures. In the process, we classify the events into two clear flux rope classes (‘three-part’, and ‘Loop’), jets and outflows (no clear structure). We find that at least 40 % of the observed CMEs have clear flux rope structures and that ～?29 % of the database entries are either misidentifications or inadequately measured and should be discarded from statistical analyses. We propose a new definition for flux rope CMEs (FR-CMEs) as a coherent magnetic, twist-carrying coronal structure with angular width of at least 40° and able to reach beyond 10 R⊙ which erupts on a time scale of a few minutes to several hours. We conclude that flux ropes are a common occurrence in CMEs and pose a challenge for future studies to identify CMEs that are clearly not FR-CMEs.  相似文献   

9.
The mass ejection event on 17 January 1974 was a classsic spray associated with a flare from an over the limb region. The structure of the accompanying coronal transient was typical of well-observed mass ejections, with coronal loops and a forerunner racing ahead of the rising prominence. Observations in H, soft X-ray, white light and radio wavelengths allowed us to track both cool (T e104 K) and hot (T e>106 K) material from limb de-occultation to 6R . We determined the kinematics and thermodynamics of the internal material, and the overall mass and energy budget of the event. The majority of the mass and energy was linked with coronal material, but at least 20% of the ejected mass originated as near-surface prominence material. We conclude that the upper part of the prominence was being continuously heated to coronal temperatures as it rose through the corona. Above 2R nearly all of the material was completely ionized. The primary acceleration of the prominence occurred below 3.5 × 104 km with all of the material exhibiting constant velocity above 1.5R . We found evidence that a moving type IV burst, indicative of strong magnetic fields, was associated with the upper part of the prominence. Our observations suggest that both the cool and hot material were acted upon by a similar, continuous force(s) to great heights and over a long time interval. We find that the observations are most consistent with magnetic propulsion models of coronal transients.  相似文献   

10.
Multi-spacecraft observations are used to study the in-situ effects of a large coronal mass ejection (CME) erupting from the farside of the Sun on 3 November 2011, with particular emphasis on the associated solar energetic particle (SEP) event. At that time both Solar Terrestrial Relations Observatory (STEREO) spacecraft were located more than 90 degrees from Earth and could observe the CME eruption directly, with the CME visible on-disk from STEREO-B and off the limb from STEREO-A. Signatures of pressure variations in the corona such as deflected streamers were seen, indicating the presence of a coronal shock associated with this CME eruption. The evolution of the CME and an associated extreme-ultraviolet (EUV) wave were studied using EUV and coronagraph images. It was found that the lateral expansion of the CME low in the corona closely tracked the propagation of the EUV wave, with measured velocities of 240±19 km?s?1 and 221±15 km?s?1 for the CME and wave, respectively. Solar energetic particles were observed to arrive first at STEREO-A, followed by electrons at the Wind spacecraft at L1, then STEREO-B, and finally protons arrived simultaneously at Wind and STEREO-B. By carrying out a velocity-dispersion analysis on the particles arriving at each location, it was found that energetic particles arriving at STEREO-A were released first and that the release of particles arriving at STEREO-B was delayed by about 50 minutes. Analysis of the expansion of the CME to a wider longitude range indicates that this delay is a result of the time taken for the CME edge to reach the footpoints of the magnetic-field lines connected to STEREO-B. The CME expansion is not seen to reach the magnetic footpoint of Wind at the time of solar-particle release for the particles detected here, suggesting that these particles may not be associated with this CME.  相似文献   

11.
The spectacular prominence eruption and CME of 31 August 2007 are analyzed stereoscopically using data from NASA??s twin Solar Terrestrial Relations Observatory (STEREO) spacecraft. The technique of tie pointing and triangulation (T&T) is used to reconstruct the prominence (or filament when seen on the disk) before and during the eruption. For the first time, a filament barb is reconstructed in three-dimensions, confirming that the barb connects the filament spine to the solar surface. The chirality of the filament system is determined from the barb and magnetogram and confirmed by the skew of the loops of the post-eruptive arcade relative to the polarity reversal boundary below. The T&T analysis shows that the filament rotates as it erupts in the direction expected for a filament system of the given chirality. While the prominence begins to rotate in the slow-rise phase, most of the rotation occurs during the fast-rise phase, after formation of the CME begins. The stereoscopic analysis also allows us to analyze the spatial relationships among various features of the eruption including the pre-eruptive filament, the flare ribbons, the erupting prominence, and the cavity of the coronal mass ejection (CME). We find that erupting prominence strands and the CME have different (non-radial) trajectories; we relate the trajectories to the structure of the coronal magnetic fields. The possible cause of the eruption is also discussed.  相似文献   

12.
Plunkett  S.P.  Vourlidas  A.  Šimberová  S.  Karlický  M.  Kotrč  P.  Heinzel  P.  Kupryakov  Yu.A.  Guo  W.P.  Wu  S.T. 《Solar physics》2000,194(2):371-391
Coronal mass ejections (CMEs) are frequently associated with erupting prominences near the solar surface. A spectacular eruption of the southern polar crown prominence was observed on 2 June 1998, accompanied by a CME that was well-observed by the LASCO coronagraphs on SOHO. The prominence was observed in its quiescent state and was followed throughout its eruption by the SOHO EIT and later by LASCO as the bright, twisted core of the CME. Ground-based H observations of the prominence were obtained at the Ondejov Observatory in the Czech Republic. A great deal of fine structure was observed within the prominence as it erupted. The prominence motion was found to rotate about its axis as it moved outward. The CME contained a helical structure that is consistent with the ejection of a magnetic flux rope from the Sun. Similar structures have been observed by LASCO in many other CMEs. The relationship of the flux rope to other structures in the CME is often not clear. In this event, the prominence clearly lies near the trailing edge of the structure identified as a flux rope. This structure can be observed from the onset of the CME in the low corona all the way out to the edge of the LASCO field of view. The initiation and evolution of the CME are modeled using a fully self-consistent, 3D axisymmetric, MHD code.  相似文献   

13.
Eit and LASCO Observations of the Initiation of a Coronal Mass Ejection   总被引：2，自引：0，他引：2  
We present the first observations of the initiation of a coronal mass ejection (CME) seen on the disk of the Sun. Observations with the EIT experiment on SOHO show that the CME began in a small volume and was initially associated with slow motions of prominence material and a small brightening at one end of the prominence. Shortly afterward, the prominence was accelerated to about 100 km s-1 and was preceded by a bright loop-like structure, which surrounded an emission void, that traveled out into the corona at a velocity of 200–400 km s-1. These three components, the prominence, the dark void, and the bright loops are typical of CMEs when seen at distance in the corona and here are shown to be present at the earliest stages of the CME. The event was later observed to traverse the LASCO coronagraphs fields of view from 1.1 to 30 R⊙. Of particular interest is the fact that this large-scale event, spanning as much as 70 deg in latitude, originated in a volume with dimensions of roughly 35" (2.5 x 104 km). Further, a disturbance that propagated across the disk and a chain of activity near the limb may also be associated with this event as well as a considerable degree of activity near the west limb.  相似文献   

14.
Lyons  M.A.  Simnett  G.M. 《Solar physics》2001,200(1-2):203-211
We report observations, from March 1999 to December 1999, of slow-moving, low-mass (1014 g) erupting structures. The 20 events seen in this period appear with a double or multiple loop structure. Their speeds range from approximately 10 to 60 km s–1. There are no significant associated flares or radio signatures. Although the speed distribution of these events overlaps that of coronal mass ejections (CMEs), we propose that they are morphologically different structures and are not merely a continuation of the lower range of the CME speed distribution. The aim of this paper is to characterize these events and to emphasize the insight into general CME research that such simple phenomena could give.  相似文献   

15.
Gopalswamy  N.  Cyr  O.C. St.  Kaiser  M.L.  Yashiro  S. 《Solar physics》2001,203(1):149-163
We report on a coronal shock wave inferred from the metric type II burst of 13 January 1996. To identify the shock driver, we examined mass motions in the form of X-ray ejecta and white-light coronal mass ejections (CMEs). None of the ejections could be considered fast (> 400 km s–1) events. In white light, two CMEs occurred in quick succession, with the first one associated with X-ray ejecta near the solar surface. The second CME started at an unusually large height in the corona and carried a dark void in it. The first CME decelerated and stalled while the second one accelerated, both in the coronagraph field of view. We identify the X-ray ejecta to be the driver of the coronal shock inferred from metric type II burst. The shock speed reported in the Solar Geophysical Data (1000–2000 km s–1) seems to be extremely large compared to the speeds inferred from X-ray and white-light observations. We suggest that the MHD fast-mode speed in the inner corona could be low enough that the X-ray ejecta is supermagnetosonic and hence can drive a shock to produce the type II burst.  相似文献   

16.
We propose a multicomponent analysis of starburst galaxies, based on a model that takes into account the young and evolved stellar components and the gas emission, with their respective extinction, in the frame of a coherent dust distribution pattern. Near-IR signatures are preferentially investigated, in order to penetrate as deep as possible into the dusty starburst cores. We computed the 1.4-2.5 μm spectra of synthetic stellar populations evolving through strong, short timescale bursts of star formation (continuum and lines, R ? 500). The evolution model is specifically sensitive to cool stellar populations (AGB and red supergiant stars). It takes advantage of the stellar library of Lançon & Rocca-Volmerange (1992) [A&ASS, 96, 593], observed with the same instrument (FTS/CFHT) as the analysed galaxy sample, so that the instrumental effects are minimised. The main near-IR observable constraints are the molecular signatures of CO and H2O and the slope of the continuum, observed over a range exceptionally broad for spectroscopic data. The H - K colour determined from the spectra measures the intrinsic stellar energy distribution but also differential extinction, which is further constrained by optical emission line ratios. Other observational constraints are the near-IR emission lines (Brγ, He I 2.06 μm, [Fe II] 1.64 μm, H2 2.12 μm) and the far-IR luminosity. The coherence of the results relies on the interpretation in terms of stellar populations from which all observable properties are derived, so that the link between the various wavelength ranges is secured. The luminosity LK is used for the absolute calibration.We apply this approach to the typical spectrum of the core of NGC 1614. Consistent solutions for the starburst characteristics (star-formation rate, IMF, burst age, morphology) are found and the role of each observational constraint in deriving satisfactory models is extensively discussed. The acceptable contamination of the K band light by the underlying population amounts ≥ 15% even through a 5 arcsec aperture. The model leads to a limit on the direct absorption of Lyman continuum photons by dust situated inside the ionised areas, which in turn, with standard gas-to-dust ratios, translates into small characteristic sizes for the individual coexisting H II regions of the massive starburst area (clusters containing ∼ 102 ionising stars). We show that room is left for IMFs extending to 120 M⊙, rather than truncated at ∼ 60 M⊙ as most conservative studies conclude. High internal velocity dispersions (≥ 20 km s−1) are then needed for the H II regions. An original feature of this work is to base the analysis of near-infrared spectral galaxy observations on a large wavelength range, using models constructed with spectral stellar data observed with the same instrument. However a broader use of this spectral evolution model on other spectral or photometric data samples is possible if the spectral resolution of the model is adapted to observations or if colours are derived from the energy distributions.Catherine J. Cesarsky  相似文献   

17.
X-ray and H observations of an erupting filament, discussed herein, and other observations of the associated flare on 1980 May 21, suggest that an erupting filament played a major role in the X-ray flare. While Antonucci et al. (1985) analyzed the May 21 flare as one of the best cases of chromospheric evaporation, the possible contribution from X-ray emitting erupting plasma has been ignored. We show that pre-heated plasma existed and may have contributed part of the blue-shifted X-ray emission observed in the Caxix line, which was formerly attributed solely to chromospheric evaporation. Thus it remains an open question - in two-ribbon flares in particular - just how important chromospheric evaporation is in flare dynamics.  相似文献   

18.
Subramanian  Prasad  Ananthakrishnan  S.  Janardhan  P.  Kundu  M.R.  White  S.M.  Garaimov  V.I. 《Solar physics》2003,218(1-2):247-259
We present the first observations of a solar flare with the GMRT. An M2.8 flare observed at 1060 MHz with the GMRT on 17 November 2001 was associated with a prominence eruption observed at 17 GHz by the Nobeyama radioheliograph and the initiation of a fast partial halo CME observed with the LASCO C2 coronagraph. Towards the start of the eruption, we find evidence for reconnection above the prominence. Subsequently, we find evidence for rapid growth of a vertical current sheet below the erupting arcade, which is accompanied by the flare and prominence eruption.  相似文献   

19.
A comprehensive case and statistical study of CME onsets has been conducted on the solar limb using the CDS, LASCO and EIT instruments aboard the SOHO spacecraft. This is the first dedicated campaign to establish firmly the EUV signatures of CME onsets and is based on a series of low-corona observing campaigns made in 2002. The event database consisted of 36 multiple emission line sequences observed with CDS and the study builds, in particular, on studies of EUV coronal dimming which have been associated with CME onsets. We witness a range of dimming events in EUV coronal emission line data. Shorter events, commonly of duration < 4 hours, we find are indirectly associated with CME onsets whereas longer-duration dimmings (> 4 hours) appear to be either due to coronal evolution or rotational effects. However, for some CME onsets, where the CDS pointing was appropriate, no dimming was observed. Dimming observed in EIT typically occurred immediately after the launch of a loop or prominence, and in 5 out of 9 events there is evidence of a matter buildup within the loop before launch. A total of 10 events occurred where CDS was used to directly observe the CME footprint, but no relationship between these events was found. The results suggest that the response of the corona to a CME launch differs between the low (1.0 R ⊙≤R≤1.2 R ⊙) and middle (1.2 R ⊙<R≤2.0 R ⊙) corona regions, hence implying a difference between dimming observations conducted with different instruments.  相似文献   

20.
Analysis of observations from both space-borne (LASCO/SOHO, Skylab and Solar Maximum Mission) and ground-based (Mauna Loa Observatory) instruments show that there are two types of coronal mass ejections (CMEs), fast CMEs and slow CMEs. Fast CMEs start with a high initial speed, which remains more or less constant, while slow CMEs start with a low initial speed, but show a gradual acceleration. To explain the difference between the two types of CMEs, Low and Zhang (2002) proposed that it resulted from a difference in the initial topology of the magnetic fields associated with the underlying quiescent prominences, i.e., a normal prominence configuration will lead to a fast CME, while an inverse quiescent prominence results in a slow CME. In this paper we explore a different scenario to explain the existence of fast and slow CMEs. Postulating only an inverse topology for the quiescent prominences, we show that fast and slow CMEs result from different physical processes responsible for the destabilization of the coronal magnetic field and for the initiation and launching of the CME. We use a 2.5-D, time-dependent streamer and flux-rope magnetohydrodynamic (MHD) model (Wu and Guo, 1997) and investigate three initiation processes, viz. (1) injecting of magnetic flux into the flux-rope, thereby causing an additional Lorentz force that will destabilize the streamer and launch a CME (Wu et al., 1997, 1999); (2) draining of plasma from the flux-rope and triggering a magnetic buoyancy force that causes the flux-rope to lift and launch a CME; and (3) introducing additional heating into the flux-rope, thereby simulating an active-region flux-rope accompanied by a flare to launch a CME. We present 12 numerical tests using these three driving mechanisms either alone or in various combinations. The results show that both fast and slow CMEs can be obtained from an inverse prominence configuration subjected to one or more of these three different initiation processes.  相似文献   

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