A STUDY OF THE KINEMATIC EVOLUTION OF CORONAL MASS EJECTIONS J' Zhang,1 K' P' Dere,2 R' A' Howard,2

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A STUDY OF THE KINEMATIC EVOLUTION OF CORONAL
MASS EJECTIONSJ. Zhang,1 K. P. Dere,2 R. A.
Howard,2 and A. Vourlidas2The Astrophysical
Journal, 604420 432, 2004 March 20?????
2004/6/7 ??
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Introduction

• the kinematic evolution of CMEs.
• Zhang et al. 2001 (Paper I) described the
  kinematic evolution of impulsive CMEs.
• Two classes of CME kinematic behavior, impulsive
  and gradual CMEs.
• the full kinematic evolution of 3 CME events
  based LASCO C1/C2/C3,to demonstrate the diversity
  of CME kinematic properties impulsive, grdual
  and intermediate CME.

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2. OBSERVATIONS AND DATA ANALYSIS

• LASCO C1, C2, and C3
• GOES X-ray 1--8 full-disk flux as flare input
• LASCO C1.. before SOHO interruption in 1998.
• Height plot of C1 and C2/C3 .. leading edge only.
• The uncertainity at 8 pxels in each image.
• numerical derivative method
• CME mass measurement.

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3.1. CME 1 Impulsive AccelerationFigure1

• 1998 June 11 event.
• GOES M1.4 class flare
• A case of Impulsive acceleration event.
• C1 FOV .. asymmetric expanding.
• C2/C3 FOV .. symmetric around the equator.
  different shape.

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3.1. CME 1 Impulsive AccelerationFigure2

• (2b) 3phase of kinematic evlution.
• initiation phase.. lt100km/s, about 1hr
• accelaration phase .. velocity increase, last for
  about 30-50 min.
• propagation phase
• CME velocity vs X-ray flux, acceleration vs X-ray
  flux derivative.

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3.2. CME 2 Intermediate AccelerationFigure3

• 2000October 25 event, no C1.
• Intermiediate acceleration event.
• GOES C4.0 flux level
• long-rise, long-fall event in X-ray. 160min for
  rise phase.

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3.2. CME 2 Intermediate AccelerationFigure4

• peak speed .. CME1
• acceleration .. 2.4 times smller than CME1
• longer duration .. 2-3 x
• CME velocity vs X-ray flux.. good temporal
  correlation for the longer rise time event.

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3.3. CME 3 Gradual AccelerationFigure5

• 1997 October 19
• Very weak but persistent accelation and slow
  velocity event.
• no apparent GOES flare

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3.3. CME 3 Gradual AccelerationFigure6

• time range is 32hr, longer than previous 2
  events.
• No impulsive or fast acceleratoin phase.
• a velocity plateau for 5 hr
• measurement gap between 05 and 08 ut.

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3.4. Summary of ResultsFigure7

• V-T plot.. CME 1 and 2 are similar

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Table1
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4. DISCUSSIONS 4.1. CME Kinematics

• 3 parameters to characerize a CMEs accelatation
  duration, magnitude, distance.
• impulsive accelaration short duration, very
  weak accelaration long duration.
• Most CME events may reside in between the
  extremely impulsive ones and the gradual ones.
• CME acceleration in the acceleration phase can
  vary by 3 orders of magnitude, duration can also
  vary by the same magnitude.

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4. DISCUSSIONS 4.1. CME Kinematics

• There is no compelling statistical evidence to
  support this classification.
• The statistical distribution of CME velocity
  always shows a continuous Gaussian distribution
  and shows no sign of a bimodal pattern.
• The average acceleration in the outer corona has
  Gaussian-like distribution.
• a large number of events observatin is rquired.
• two-class CME classification is oversimlified.

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4.2. Relationship between CMEs and Flares

• correlation between CME velocity profiles and
  soft X-ray flux profile, also for their
  derivatives.
• CMEs and flares are physically integrated
  phenomena.
• CME location
• X-ray particle acceleration vs CME property.
• particle acceleration and large-scale CME
  acceleration are phusically related.

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5. CONCLUSIONS

• property of 3 CMEs
• CME acceleration can vary by 3 orders of
  magnitude from several m s -2 to several thousand
  m s -2, while the acceleration duration can also
  vary.
• CME larrge-scale acceleration and flare particle
  acceleration are driven by the same physical
  process or by multiple processes that are
  physicaly coupled in the corona.