Chromospheric Anemone Jets Outside of Sunspots in Active Regions

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Chromospheric Anemone Jets Outside of Sunspots in
Active Regions
2007 Aug 22, First Results from Hinode,
Dublin, Ireland

• K. Shibata
• Kwasan and Hida Obs., Kyoto Universityand
• T. Nakamura, N. Nishizuka,
• T. Matsumoto, K. Otsuji, S. Nagata,
• Kyoto/Kwasan-Hida team, Hinode/SOT team

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Introduction

• Yohkoh/SXT discovered X-ray jet (Shibata et al.
  1992, Strong et al. 1992, Shimojo et al.
  1996)

Anemone (Shibata et al. 1994)
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2D-MHD simulation of jetsbased on reconnection
model(Yokoyama and Shibata 1995, 1996)
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Polar X-ray jets observed by Hinode/XRT
Origin of high speed solar wind ? Source of
Alfven waves ? (Cirtain et al. 2007)
(Shimizu et al. 2007)
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Prediction of ubiquitous jets in the solar
atmosphere (Shibata 1998)
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Question

• Has Hinode really observed ubiquitous cool jets ?

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Answer Yes !Discovery of many jets in Ca II H
images

• Dec 17 2000-2100 UT CaII H broad band filter
  images taken with Hinode/SOT

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No.1 2006 Dec 17 2000-2100
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No. 22006 Dec 17 2000-2100
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No. 32006 Dec 17 2000-2100
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Various Ca II H jets
Yohkoh Anemone X-ray jet
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Relation to magnetic field

• CaII H FG Stokes V

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What is the velocity of Ca jet ?

• Time-distance diagram

typical velocity 10 20 km/s
Jet Velocity 1020 km/s Alfven velocity in
the low chromospehre or photosphere gt
consistent with reconnection model
2007 Jan 14 jet
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Velocity 5 20 km/s
Nakamura et al. (2007)
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Length 500 - 2000 km
Nakamura et al. (2007)
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Width 100 300 km
Nakamura et al. (2007)
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Life time 100 - 200 sec
Nakamura et al. (2007)
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Relation between velocity and length of the jet
Velocity (km)
Length (10 km)
Nakamura et al. (2007)
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Meaning of velocity of jet

• If the jet is ejected at 10 km/s with ballistic
  motion, maximum height of the jet would be

So the jet cannot reach height greater than 200km
!
This suggests that the jet may be accelerated by
slow mode shock (or Alfven wave) generated by
reconnection
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Shibata(1998)s prediction
Shibata, Suematsu et al. (1982) showed that if an
explosion occur below middle chromosphere, the
jet is produced by slow shock generated by the
explosion
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density
height
1D MHD simulation Saitoh, Kudoh, Shibata (2001)
ApJ
Slow shock
time
cf) rebound shock Model (Sterling)
Hinode Observation
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Relation between velocity and length of the jet
Velocity (km)
Length (10 km)
Nakamura et al. (2007)
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Relation between velocity and length of the jet
Velocity (km)
Velocity-Length relation for slow shock jet
model (Shibata and Suematsu 1982)
L?V2 /g ? V (g ? V) Hansteen et al. 2006
Length (10 km)
Nakamura et al. (2007)
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Conclusion

• Hinode discovered ubiquitous Ca jets (anemone
  jets) in the solar chromosphere
• Width 100 - 300 km, length 500 - 2000 km,
  Velocity 5 20 km/s, lifetime 100 200 sec
• there is evidence of reconnection such as
  morphology (anemone) and magnetic field
  distribution, suggesting ubiquitous
  reconnection in the solar atmosphereas
  conjectured by Parker (1988)
• Chromoshperic anemone jet seems to be accelerated
  by slow mode shock generated by the
  reconnection(Shibata et al. 1982, Shibata and
  Suematsu 1982) .