The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Bojan Vršnak - One of the best experts on this subject based on the ideXlab platform.
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impulsive Acceleration of coronal mass ejections ii relation to soft x ray flares and filament eruptions
The Astrophysical Journal, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1, and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 coronal mass ejections (CMEs) in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights, and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events that were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME Acceleration ends after the soft X-ray (SXR) peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than ±5 minutes, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections ii relation to sxr flares and filament eruptions
arXiv: Solar and Stellar Astrophysics, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1 and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 CMEs in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events which were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration, and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME accleration ends after the SXR peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than \pm5 min, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections i statistics and cme source region characteristics
arXiv: Solar and Stellar Astrophysics, 2011Co-Authors: B. M. Bein, Nicolas Muhr, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs), from their initiation, through the impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity and Acceleration profiles and statistically analysed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration and size of the CME source region. The CME peak Accelerations derived range from 20 to 6800 m s^2 and are inversely correlated to the Acceleration duration and to the height at peak Acceleration. 74% of the events reach their peak Acceleration at heights below 0.5 Rsun. CMEs which originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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IMPULSIVE Acceleration OF CORONAL MASS EJECTIONS. I. STATISTICS AND CORONAL MASS EJECTION SOURCE REGION CHARACTERISTICS
The Astrophysical Journal, 2011Co-Authors: B. M. Bein, Nicolas Muhr, S. Berkebile-stoiser, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs) from their initiation through impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity, and Acceleration profiles and statistically analyzed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration, and size of the CME source region. The CME peak Accelerations we derived range from 20 to 6800 m s-2 and are inversely correlated with the Acceleration duration and the height at peak Acceleration. Seventy-four percent of the events reach their peak Acceleration at heights below 0.5 R sun. CMEs that originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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Acceleration phase of coronal mass ejections i temporal and spatial scales
Solar Physics, 2007Co-Authors: Bojan Vršnak, A. M. Veronig, Manuela Temmer, Darije Maricic, A L Stanger, Dragan RosaAbstract:We study kinematics of 22 coronal mass ejections (CMEs) whose motion was traced from the gradual pre-Acceleration phase up to the post-Acceleration stage. The peak Accelerations in the studied sample range from 40, up to 7000 m s−2, and are inversely proportional to the Acceleration phase duration and the height range involved. Accelerations and velocities are, on average, larger in CMEs launched from a compact source region. The Acceleration phase duration is proportional to the source region dimensions; i.e., compact CMEs are accelerated more impulsively. Such behavior is interpreted as a consequence of stronger Lorentz force and shorter Alfven time scales involved in compact CMEs (with stronger magnetic field and larger Alfven speed being involved at lower heights). CMEs with larger Accelerations and velocities are on average wider, whereas the widths are not related to the source region dimensions. Such behavior is explained in terms of the field pile-up ahead of the erupting structure, which is more effective in the case of a strongly accelerated structure.
Manuela Temmer - One of the best experts on this subject based on the ideXlab platform.
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impulsive Acceleration of coronal mass ejections ii relation to soft x ray flares and filament eruptions
The Astrophysical Journal, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1, and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 coronal mass ejections (CMEs) in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights, and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events that were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME Acceleration ends after the soft X-ray (SXR) peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than ±5 minutes, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections ii relation to sxr flares and filament eruptions
arXiv: Solar and Stellar Astrophysics, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1 and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 CMEs in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events which were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration, and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME accleration ends after the SXR peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than \pm5 min, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections i statistics and cme source region characteristics
arXiv: Solar and Stellar Astrophysics, 2011Co-Authors: B. M. Bein, Nicolas Muhr, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs), from their initiation, through the impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity and Acceleration profiles and statistically analysed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration and size of the CME source region. The CME peak Accelerations derived range from 20 to 6800 m s^2 and are inversely correlated to the Acceleration duration and to the height at peak Acceleration. 74% of the events reach their peak Acceleration at heights below 0.5 Rsun. CMEs which originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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IMPULSIVE Acceleration OF CORONAL MASS EJECTIONS. I. STATISTICS AND CORONAL MASS EJECTION SOURCE REGION CHARACTERISTICS
The Astrophysical Journal, 2011Co-Authors: B. M. Bein, Nicolas Muhr, S. Berkebile-stoiser, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs) from their initiation through impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity, and Acceleration profiles and statistically analyzed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration, and size of the CME source region. The CME peak Accelerations we derived range from 20 to 6800 m s-2 and are inversely correlated with the Acceleration duration and the height at peak Acceleration. Seventy-four percent of the events reach their peak Acceleration at heights below 0.5 R sun. CMEs that originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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Acceleration phase of coronal mass ejections i temporal and spatial scales
Solar Physics, 2007Co-Authors: Bojan Vršnak, A. M. Veronig, Manuela Temmer, Darije Maricic, A L Stanger, Dragan RosaAbstract:We study kinematics of 22 coronal mass ejections (CMEs) whose motion was traced from the gradual pre-Acceleration phase up to the post-Acceleration stage. The peak Accelerations in the studied sample range from 40, up to 7000 m s−2, and are inversely proportional to the Acceleration phase duration and the height range involved. Accelerations and velocities are, on average, larger in CMEs launched from a compact source region. The Acceleration phase duration is proportional to the source region dimensions; i.e., compact CMEs are accelerated more impulsively. Such behavior is interpreted as a consequence of stronger Lorentz force and shorter Alfven time scales involved in compact CMEs (with stronger magnetic field and larger Alfven speed being involved at lower heights). CMEs with larger Accelerations and velocities are on average wider, whereas the widths are not related to the source region dimensions. Such behavior is explained in terms of the field pile-up ahead of the erupting structure, which is more effective in the case of a strongly accelerated structure.
A. M. Veronig - One of the best experts on this subject based on the ideXlab platform.
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impulsive Acceleration of coronal mass ejections ii relation to soft x ray flares and filament eruptions
The Astrophysical Journal, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1, and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 coronal mass ejections (CMEs) in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights, and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events that were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME Acceleration ends after the soft X-ray (SXR) peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than ±5 minutes, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections ii relation to sxr flares and filament eruptions
arXiv: Solar and Stellar Astrophysics, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1 and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 CMEs in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events which were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration, and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME accleration ends after the SXR peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than \pm5 min, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections i statistics and cme source region characteristics
arXiv: Solar and Stellar Astrophysics, 2011Co-Authors: B. M. Bein, Nicolas Muhr, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs), from their initiation, through the impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity and Acceleration profiles and statistically analysed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration and size of the CME source region. The CME peak Accelerations derived range from 20 to 6800 m s^2 and are inversely correlated to the Acceleration duration and to the height at peak Acceleration. 74% of the events reach their peak Acceleration at heights below 0.5 Rsun. CMEs which originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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IMPULSIVE Acceleration OF CORONAL MASS EJECTIONS. I. STATISTICS AND CORONAL MASS EJECTION SOURCE REGION CHARACTERISTICS
The Astrophysical Journal, 2011Co-Authors: B. M. Bein, Nicolas Muhr, S. Berkebile-stoiser, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs) from their initiation through impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity, and Acceleration profiles and statistically analyzed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration, and size of the CME source region. The CME peak Accelerations we derived range from 20 to 6800 m s-2 and are inversely correlated with the Acceleration duration and the height at peak Acceleration. Seventy-four percent of the events reach their peak Acceleration at heights below 0.5 R sun. CMEs that originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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Acceleration phase of coronal mass ejections i temporal and spatial scales
Solar Physics, 2007Co-Authors: Bojan Vršnak, A. M. Veronig, Manuela Temmer, Darije Maricic, A L Stanger, Dragan RosaAbstract:We study kinematics of 22 coronal mass ejections (CMEs) whose motion was traced from the gradual pre-Acceleration phase up to the post-Acceleration stage. The peak Accelerations in the studied sample range from 40, up to 7000 m s−2, and are inversely proportional to the Acceleration phase duration and the height range involved. Accelerations and velocities are, on average, larger in CMEs launched from a compact source region. The Acceleration phase duration is proportional to the source region dimensions; i.e., compact CMEs are accelerated more impulsively. Such behavior is interpreted as a consequence of stronger Lorentz force and shorter Alfven time scales involved in compact CMEs (with stronger magnetic field and larger Alfven speed being involved at lower heights). CMEs with larger Accelerations and velocities are on average wider, whereas the widths are not related to the source region dimensions. Such behavior is explained in terms of the field pile-up ahead of the erupting structure, which is more effective in the case of a strongly accelerated structure.
B. M. Bein - One of the best experts on this subject based on the ideXlab platform.
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impulsive Acceleration of coronal mass ejections ii relation to soft x ray flares and filament eruptions
The Astrophysical Journal, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1, and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 coronal mass ejections (CMEs) in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights, and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events that were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME Acceleration ends after the soft X-ray (SXR) peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than ±5 minutes, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections ii relation to sxr flares and filament eruptions
arXiv: Solar and Stellar Astrophysics, 2012Co-Authors: B. M. Bein, A. M. Veronig, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:Using high time cadence images from the STEREO EUVI, COR1 and COR2 instruments, we derived detailed kinematics of the main Acceleration stage for a sample of 95 CMEs in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak Accelerations and lower Acceleration phase durations, initiation heights and heights, at which they reach their peak velocities and peak Accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive Accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak Acceleration significantly lower values than for events which were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME Acceleration duration, and negatively correlated with the CME peak Acceleration. For the majority of the events the CME Acceleration starts before the flare onset (for 75% of the events) and the CME accleration ends after the SXR peak time (for 77% of the events). In ~60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME Acceleration is smaller than \pm5 min, which hints at a feedback relationship between the CME Acceleration and the energy release in the associated flare due to magnetic reconnection.
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impulsive Acceleration of coronal mass ejections i statistics and cme source region characteristics
arXiv: Solar and Stellar Astrophysics, 2011Co-Authors: B. M. Bein, Nicolas Muhr, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs), from their initiation, through the impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity and Acceleration profiles and statistically analysed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration and size of the CME source region. The CME peak Accelerations derived range from 20 to 6800 m s^2 and are inversely correlated to the Acceleration duration and to the height at peak Acceleration. 74% of the events reach their peak Acceleration at heights below 0.5 Rsun. CMEs which originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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IMPULSIVE Acceleration OF CORONAL MASS EJECTIONS. I. STATISTICS AND CORONAL MASS EJECTION SOURCE REGION CHARACTERISTICS
The Astrophysical Journal, 2011Co-Authors: B. M. Bein, Nicolas Muhr, S. Berkebile-stoiser, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs) from their initiation through impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity, and Acceleration profiles and statistically analyzed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration, and size of the CME source region. The CME peak Accelerations we derived range from 20 to 6800 m s-2 and are inversely correlated with the Acceleration duration and the height at peak Acceleration. Seventy-four percent of the events reach their peak Acceleration at heights below 0.5 R sun. CMEs that originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
I. Kienreich - One of the best experts on this subject based on the ideXlab platform.
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impulsive Acceleration of coronal mass ejections i statistics and cme source region characteristics
arXiv: Solar and Stellar Astrophysics, 2011Co-Authors: B. M. Bein, Nicolas Muhr, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, S Berkebilestoiser, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs), from their initiation, through the impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity and Acceleration profiles and statistically analysed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration and size of the CME source region. The CME peak Accelerations derived range from 20 to 6800 m s^2 and are inversely correlated to the Acceleration duration and to the height at peak Acceleration. 74% of the events reach their peak Acceleration at heights below 0.5 Rsun. CMEs which originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
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IMPULSIVE Acceleration OF CORONAL MASS EJECTIONS. I. STATISTICS AND CORONAL MASS EJECTION SOURCE REGION CHARACTERISTICS
The Astrophysical Journal, 2011Co-Authors: B. M. Bein, Nicolas Muhr, S. Berkebile-stoiser, A. M. Veronig, I. Kienreich, D. Utz, Manuela Temmer, Bojan VršnakAbstract:We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs) from their initiation through impulsive Acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity, and Acceleration profiles and statistically analyzed characteristic CME parameters: peak Acceleration, peak velocity, Acceleration duration, initiation height, height at peak velocity, height at peak Acceleration, and size of the CME source region. The CME peak Accelerations we derived range from 20 to 6800 m s-2 and are inversely correlated with the Acceleration duration and the height at peak Acceleration. Seventy-four percent of the events reach their peak Acceleration at heights below 0.5 R sun. CMEs that originate from compact sources low in the corona are more impulsive and reach higher peak Accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME Accelerations and decreases with height and CME size.
