1. ICME in the Solar Wind from STEL IPS Observations
Munetoshi Tokumaru
(STEL, Japan)

2. Interplanetary Scintillation (IPS) Measurements as a Useful Tool for the Space Weather Study
White Light Image of Solar Corona
Sun
Earth
CME
Radio Source
Shock
Magnetic Cloud
(SOHO/LASCO)
Coronal Mass Ejection (CME)
Interplanetary scintillation (IPS) observations serve as a useful tool to study 3D feature of CME and radial evolution in the solar wind.
The utility of IPS observations has been well demonstrated from earlier studies using Cambridge, Pushchino, Ooty, and STEL data.

3. Projection map of g-values between
Interplanetary CME Identified from STEL IPS Observations
The g-value represents the relative variation of scintillation level; i.e. solar wind density fluctuations ΔNe (Gapper et al., 1982).
STEL IPS observations:
Frequency: 327 MHz No. Sources: ~40 sources (ε<90 deg) in a day
LASCO(C3) Observations
SOHO/LASCO
Projection map of g-values between
2000/7/11:22h UT and 7/12:7h UT
g>1 → Excess of ΔNe (i.e. Ne) →Interplanetary CME

4. Retrieval of 3D Structure of Interplanetary CME by Model Fitting Analysis
ΔNe Model
Observed　g-map
Line-of-Sight
Sun
Earth
ΔNe: Density fluctuations
K: Normalizing factor
w(z): IPS weightening function
z: Distance along los
q: Spectral index
Ψ: Apparent source size
λRF: Observing wavelength
Search for the best-fit parameters
(Cf. Tappin, 1987)
Tokumaru, M., et al., AIP Conference Proc. 679, pp

6. 2000 Jul 10 CME Event
LASCO
Solid line: “Snowplow” model
Dash-dot Line: “Aerodynamic Drag” model
Parameters:
Ambient SW: V=400km/s, N=5/cc
(LASCO obs.)
Initial Speed =1352 km/s
Initial Mass =1.1×1016 g
(IPS obs./model fit)
Radial thickness=0.16 AU
Angular extent/4π=0.17
Models
IPS
ssc
This slide shows variation of CME speeds from the corona to the Earth orbit for a given event. These two lines are model calculations.
In these models, the interaction between the solar wind and the CME is a dominant process.
In this case, our IPS observations show good agreement with these model calculations, and this is consistent with the shocked plasma hypothesis.
IPS observations shows good agreement with model calculations.
Radial variation of average speeds
IPS obs: ○ Central Axis, ● Earthward

7. 3D Density Reconstruction of IP Disturbances Associated with the 2003 October 28 CME
STEL IPS（g-value） Measurements (Left)
White-Light Measurements with Solar Mass Ejection Imager (Right)
Slower Speed than IP Shock（~1000km/s)　→Internal Part of CME
Elongated Structure in NE-SW
High-density cloud
IPS
SMEI (UCSD)
Tokumaru et al., J. Geophys. Res., 112, A05106, doi: /2006JA012043
3D Distribution of Density Enhancements：Yellow dot=Sun、Blue dot=Earth、Solid circle=Earth Ortbit
Both data show loop-shaped structure. Tokumaru, M. et al., J. Geophys. Res., 112, A05106, doi: /2006JA012043

8. Magnetic Flux Rope Associated with 2003 October 28 CME Cosmic Ray (Muon) Observations (Left) & In situ Measurements by ACE(Right)
In situ (ACE) Obs.
Cosmic Ray Obs.
A: in situ (ACE)
IPS
IPS
lat=46 deg
lon=54 deg
lat=29 deg
lon=75 deg CR
B: Kuwabara et al, 2004
C: Kuwabara, 2005
Distribution of IP disturbances observed by IPS and SMEI is in good agreement with the magnetic flux rope.
Kuwabara, 2005

9. Global Feature of CMEs in the Solar Wind
Shell-shaped CMEs
1999 Sep 20 event
2000 Jul 10 event
2000 Jun 2 event
Loop-shaped Type
1999 Aug 17 event
2000 Jul 14 event
1999 Apr 13 event
2001 Aug 25 event

10. Origins of Density Enhancement Identified by IPS
Compressed Plasma between Shock and Ejecta
Prominence Material Contained by a Flux Rope

11. Sumary
3D distribution of ICMEs has been retreived from IPS observations using the model fitting technique.
A variety of global morphology has been revealed from this analysis.
3D IPS reconstructions are useful for studying propagation and origin of ICMEs.

13. 2003 Nov 02 CME Event Solid line: “Snowplow” model (11/2-3)
Dashed line: “Snowplow” model (11/3-4)
Dash-dot line: “Aerodynamic Drag” model (11/2-3)
Dash-dot-dot-dot line: “Aerodynamic Drag” model (11/3-4)