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Identification of Prominence Material in Magnetic Cloud

Shuo Yao China University of Geosciences (Beijing)

yaoshuo@cugb.edu.cn

Co-authers: E. Marsch2, C.-Y. Tu1 and R. Schwenn2 1: Department of Geophysics, Peking University, China 2: Max-Planck-Institut for Solar System Research, Germany

ILWS Workshop 2011, Friendship Hotel, Beijing, China

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Background

1. CME

Bright loop---plasma pile up

Dark cavity---magnetic flux ropes

Bright core---prominence

3-part CME

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2. Magnetic CloudOne type of

Interplanetary Coronal Mass

Ejection (ICME) Enhanced magnetic field

strength Smooth rotation of

magnetic field vector in day’s time

Low proton temperature

171 172 173

Helios 1 1981 DOY171-173

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Prominence Filament

NASA SOHO

3. Prominence Material

Cold and dense material from chromosphere

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Temperature: 5000-8000K

Character Ions: He+

Position in CME: Centre of the flux rope Priest 1989, Crooker and Horbury 2005

Zong et al,.2004Gopalswamy, 2006

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？

Forbes et al., 2001

3. The problem

Bothmer and Schwenn, 1998

Identification of 3-Part CME From In Situ MC Observations----Especially the prominence material !!

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Report Flux Rope Np and Tp He+

However, not all the features identified in one event…….

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My workAim: identify prominence material from the in-situ observation of magnetic cloud.Cases:1979DOY129, at 0.3 AU

1976 DOY 90, at 0.5 AU

1978DOY358, at 0.7 AU

Evidences:

1.High Np and low Tp

2.Located on centre of magnetic field flux rope

3.Existence of He+

4. Heating before and after revealed by Velocity distribution function (temperature )

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1. SatelliteHelios 2: 1976-1980

electrostatic analyzers

0.3 AU

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Case 1

0.3 AU

High Np and low Tp

Flux rope structure

2. Case Study

Yao et al., 2010, JGR

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Possible existence of He+

H+ : He2+ : He+ m 1 4 4q 1 2 1m/q 1 2 4

E/q E/q~m/q

Yao et al., 2010, JGR

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Thermal velocity distribution functions

Heating perpendicular to B

Solid Line——local B

X——outward solar radial direction

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22 Hours ahead ， Solwind observed CME with prominence eruption

Sheeley ， 1980

SOLWIND Observation

600km/s×22h

~4.5×107 km ~0.3 AU

1AU~1.5×108 km

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Case 2

0.5 AU

High Np and low Tp

Flux rope structure

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Possible existence of He+

H+ : He2+ : He+ m 1 4 4q 1 2 1m/q 1 2 4

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Thermal velocity distribution functions

Heated Plasma Before and After Prominence Material

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Case 3

0.7 AU

low Tp and High Np

Flux rope structure

Prominence material is 2 hours behind the neutral line of flux rope.

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Possible existence of He+

H+ : He2+ : He+ m 1 4 4q 1 2 1m/q 1 2 4

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Thermal velocity distribution functions

Heated Plasma Before and After Prominence Material

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Report Flux Rope Np and Tp He+

Yao 2010 X X X

Complete evidences from in situ measurements

Summary

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SOHO

Gopalswamy SpaceSciRew, 2006 Yao et al., 2010, JGR

NASA

Remote Observation

Model

In situ measurement

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It seems….Closer to the Sun, the more info about CME

So…we do expect more on Solar Orbiter & Solar Probe+ in the Next Cycle ….

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Thanks !