Coronal Mass Ejections 5: Propagation

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Coronal Mass Ejections 5Propagation
Interaction

• CME Solar Wind Coupling
• CME-CME interactions
• Radio Signatures (Energetic Electrons)
• Solar Energetic Particles
• Nat Gopalswamy, NASA GSFC, Greenbelt, MD
• August 12 2002 Weihai, China

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Most Fast CMEs Seem to Decelerate

• All fast CMEs (gt700 km/s) decelerate
• Trend similar to that of DH CMEs

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Fast CMEs Decelerate More

• Deceleration and CME speed are correlated
• Deceleration scales as square of the initial
  speed
• Includes halos

Gopalswamy et al., 2001 JGR
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Why Fast CMEs Decelerate?

• Propelling force (Range?) ()
• Gravity (-)
• Drag Force Cd .A.n.(ucme - usw)2 (-)
• - Density (n), area, small solar wind speed, and
  high CME speed are against CME motion
• Deceleration, consistent with observations

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What Happens over Larger Distances from the Sun?
Remote sensing (SOHO) and In situ
(Wind) Observations Fast CMEs decelerate
Slow CMEs accelerate Range of speeds is
narrow at 1AU
Gopalswamy et al., GRL, 27, 145, 2000
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The CME Arrival Model

• Interplanetary acceleration a (v-u)/t from
  observations
• v in situ speed from Wind
• u speed of CME near the Sun using SOHO/LASCO
• t transit time
• Plot a versus u to get
• a 2.193 0.0054 u
  (1)
• (a refined using Helios-1/PVO P78-1 in
  quadrature
• Assuming that the acceleration behaves the same
  way for future CMEs, the CME arrival time was
  obtained from 
• S ut 0.5at2 ,
  (2)

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CME Arrival Model

• a 2.193 0.0054 u (1)
• S ut ½ at2 (2)
• a 0 for S gt0.76 AU
• u t (days)
• 200 4.3
• 500 4.2
• 1000 2.6
• 1500 1.5
• 2000 1.06
• 2500 0.81
• 3000 0.66 Carrington

Brueckner
No accel. For Sgt.76 AU
Bastille
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ICME Speeds from CME Speeds
Gopalswamy et al. 2001
Use Piston-Shock Relation to predict shock
arrival times
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CME Interactions Near the Sun

• CME interaction Cannibalism or deflection
  depending on the separation between solar sources
• CME-CME CME-shock interactions Multiple
• Radio signature typically precedes the
  intersection of the leading edge trajectories
• There are more CME interactions without radio
  signature.

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CME interaction CMEs in the SW NW are
overtaken by a larger CME
The Snow Storm in LASCO images is due To SEPs
reaching SOHO Detectors
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A Type II Radio Burst
Type III (e beams)v 0.3 c, Type II (shocks) v
1000 km/s
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Something after the type II!
Type II
?
III
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Two Fast CMEs, 100 deg Apart
CME1 600 km/s
CME2 850 km/s
Shock ahead of CME2 passes through CME1
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Source Regions of 1997 11 04 CMEs Yohkoh/SXT
CME2
CME1
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Shock Passing Through a CME
Radio emission due to CME1-shock2 interaction
CME2 h-t measured along the position angle of
interaction
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A Slow CME is Deflected

• Slow CME (290 km/s) overtaken by a fast CME (660
  km/s)
• The slow CME core deflected to the left from its
  trajectory

LASCO C3 movie
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2000 06 10
Gopalswamy et al. 2001 ApJ Lett. 548, L91, 2001
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Two Fast CMEs EIT Diff. LASCO C2 images
2354 UT
2230 UT
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20010120 CMEs

• Two fast CMEs from the same region, two hours
  apart
• Both driving shocks
• Intense radio emission following the second
• The second CME sees a different corona, viz,
  the first CME

EIT 195 movie showing the source of the two fast
CMEs
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Wind/WAVES Radio Burst
SOHO/LASCO Trajectories
CME1 830 km/s CME2 1460 km/s Shocks see
different environments
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The two CMEs are indistinguishable at 2342
UT(Cannibalism)
830 km/s
1460 km/s
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1999 09 03 Radio Emission Only during CME
interaction
A slow CME (288 km/s) Overtaken by a Fast CME
(565 km/s) Radio emission starts Only during
interaction
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99/09/03 CMEs
0141 UT
No Radio Emission Before interaction!
Reconnection??
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Slope Change 2000/06/06
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2000 06 06 CME interaction

• Slow CME (337 km/s) followed by fast CME (940
  km/s)
• Both eruptions from the same region on the Sun

LASCO C3 Movie
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2000 10 16Triple?
LASCO C2-C3 Movie
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CME-Streamer Interaction 01/02/11
II
III
??
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How Frequent? 24 of All CMEs interact
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Colliding CMEs Multiple Interactions
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Colliding CMEs SEPs
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A recent example 2001/06/15
Radio enhancement
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CME interaction SEPs A narrow CME in the SW is
overtaken by a larger CME
The Snow Storm in LASCO images is due To SEPs
reaching SOHO Detectors ? GOES protons
Click on the image to start movie
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2001/10/01 Electrons Protons
Protons and electrons were accelerated during the
2001/10/01 CME. The type II enhancements may be
due to CME interactions.
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Multiple Preceding CMEs

• The 2001/10/01 SEP event. The primary CME (Red)
  at 0530 UT was preceded by at least four CMEs
  (Blue) whose trajectories intersected with that
  of the primary. The black CMEs did not interact.

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97/11/04 SEPs

• GOES SEPs
• 10 MeV (red)
• 50 MeV (blue)
• 100 MeV (green)

CME height-time plots around SEP onset
GOES flare data
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Primary CME Speed Source Longitude

• SEP CMEs are very fast
• (gt 900km/s)
• They occur west of E45

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Preceding CMEs are slow
The speed of preceding CMEs is small ? may not
provide seed particles. Preceding fast CME
may provide seed particles for the following
shock
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Onset Time Diff Intersection of Trajectories
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CME Interaction SEPs Statistics
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Inverse Study Fast Wide CMEs

• 52 fast (gt 900km/s) Wide (gt 60deg) frontside,
  western hemispheric CMEs

minor
Marginal
Including streamer interaction
CME Interaction discriminates SEP-poor from
SEP-rich
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Implications of SEP Association with CME
interactions

• SEP-producing CMEs are almost always launched
  into preceding CMEs
• SEP acceleration not from plain solar wind
• Shock strengthening
• particles trapped in preceding CME loops
• Interaction close to Sun
• ? Time Dependence of SEP charge state
  composition (before and after interaction)
• Density/Temperature Effects
• Additional stripping by dense preceding CMEs
• Seed particles from preceding shocks
• High temperature/density from preceding CME core
• ?Mixed impulsive-gradual signatures

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IP Consequences

• Complex Geomagnetic Storms
• Complex Ejecta (extended)
• Complex He/He signatures

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Multiple Interactions
Consequences of the multiple CMEs during Nov
23-27,2000 Complex ICME (Fe charge state) Shocks
(S1-S6) Complex Dst
1
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Multiple Halo CMEs
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Complex Dst ? Multiple CMEs

• A set of 14 complex geomagnetic storms between
  1997 and 2000 examined
• Most of them have multiple solar sources
  suggesting possible CME interaction

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MC CE May 1-7, 1998
Burlaga et al. 2001
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Complex Ejecta

• Complex Dst due to complex ejecta of May 2-7,
  1998
• Complex ejecta due to interacting CMEs?

S
MC Complex Ejecta
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Summary1

• CME interaction cannibalism or deflection
  depending on the separation between solar sources
• CME-CME CME-shock interactions Triple
• Radio signature typically precedes the
  intersection of the leading edge trajectories
• There may be more CME interactions without radio
  signature!

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Summary2

• Radio signatures  associated with CME
  interaction
• - Enhancement following type II burst
• - Pure enhancement
• - Type II slope change
• - Irregular enhancements
• ? complex-shock strengthening, new shock or new
  acceleration

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Summary 3

• CME interaction occurs during most of the SEP
  events
• Acceleration from preceding CMEs
• Mixed impulsive-gradual signatures
• Time-dependence of C/S composition

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Summary4

• Interplanetary Consequences
• - Complex IP ejecta - Extended Geomagnetic
  Storms - Different counts near the Sun and at 1
  AU - Complex distribution of composition