1 / 26

A New Solar Flare Scenario - High-beta Plasma Disruption -

A New Solar Flare Scenario - High-beta Plasma Disruption -. Kiyoto Shibasaki ( Nobeyama Radio Observatory).

arlena
Download Presentation

A New Solar Flare Scenario - High-beta Plasma Disruption -

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A New Solar Flare Scenario- High-beta Plasma Disruption - Kiyoto Shibasaki (Nobeyama Radio Observatory) Nobeyama one-day Symposium

  2. ACTON: I have difficulty thinking of things that I can’t draw pictures of, and Dr. Zirin’s comment reminds me of something that has puzzled me for a long time. If one looks at the H-alpha image of a larger solar flare, one sees an enormously complicated and convoluted object in the chromosphere, extending over a very large area. We now think that this brightening results from heat conducted from above.This says that in the corona the hot volumes must be interconnected in a most complex topology. The means by which this complex topology is established might be a key to understanding the whole flare process. I have become convinced that loops are physically interacting. But if I try to draw a picture of interacting loops, I find that the interaction can only take place on a surface. How can appreciable magnetic flux be annihilated there? The result in any case is that substantial volumes are filled with hot plasma. How does it get there?It seems to me that there are things happening to affect the transport of energy transverse to the field lines, and in a very complicated topology. I wonder if there is anybody here smart enough to explain how this happens? GROUP: (Hollow laughter.) from Solar Phys. 86 (1983)

  3. Contents • Current standard solar flare model • Difficulties with the current model • Flare observations (movies) • Proposal of a new solar flare model (high-beta plasma disruption) • Application to the observed phenomena • Further studies

  4. Current Standard Solar Flare Model model Computer simulation by　Yokoyama

  5. YOHKOH Observation (I) Soft X-ray Telescope（SXT)

  6. YOHKOH Observation (II) SXT　＆HXT

  7. Difficulties • How to store all flare energy in a very thin current layer (we cannot observe due to its thinness) • Plasma inflow observation (one candidate) • How to realize the high energy state and how to keep it as quasi-equilibrium until release • Number problem (thermal, non-thermal)

  8. Observation by NoRH

  9. Observation（TRACE/EUV） • １９９９ Oct. 22 (171Å, 1MK) • 2001 Nov. 01 • 2001 Nov. 27 • 2001 Sep. 18 • 2002 Apr. 21 • 2002 May 27

  10. Flare Configuration (Non-thermal)

  11. Low-beta scenario Magnetic free energy (= current) Dissipation by reconnection High-beta scenario Plasma free energy (confinement, curvature, flow) Dissipation by High-beta disruption (ballooning instability) Flare Scenarios

  12. High-beta Disruption Scenario of Solar Flares(Shibasaki, ApJ 557, 2001) • Activities in small loops: • Small curvature • High density • Flows along loops • Activities above loops • Injection from small loop to large loop • Parallel magnetic field configuration (small, large loops)

  13. Centrifugal force by thermal motion and bulk flow V.S. Gravity gc ＝　ｖ２/R Bulk flow Thermal motion gc/go ~ 6 T6/R9 gc/go ~ 4 V72/R9 go R9

  14. Centrifugal Force v.s. Magnetic Tension Fc Bulk Flow Thermal motion Fc / Ft = 2βk Fc / Ft = βT Ft

  15. βk = (1/2)ρV2 / (B2/8π） = 2.1 ×N9V72 / BG2 βT = P / (B2/8π） = 6.9 ×N9T6 / BG2 βg = ρgoR / (B2/8π） =1.1 ×N9R9 / BG2 κc　=　1 / R κP = ∂ln(P)/∂ｎ 　　　　=　1 / lP κB =∂ln(B2/8π）/∂ｎ = 1 / lB Definitions

  16. Equilibrium at the outer surface βTκP +κB = 2κc(1+βg/2‐βk) Instability condition βT＞2（lp/R）・ 　　　　　（ 1+βg/2‐βk ） Growth time τ(s) ~100 √(lp9R9/T6) Equilibrium and Instability conditions

  17. Magnetosphere

  18. High-beta Disruption in Tokamaks

  19. Prominence Eruption and Ballooning Ballooning Instability （turbulence, particle accel., ejection,,,） １７GHｚ Prominence Eruption Spot Flare ribbons Event on 1999 Oct. 20

  20. Summary and Conclusions • Common Features in Flares and Balloons: • Turbulence, plasma ejection, high-energy particle acceleration (upward and downward), loop top plasma blobs, over-the-loop activity, impulsive nature, quasi-periodicity in particle acceleration

  21. Further Studies • Beta loading mechanism • Energetics • High cadence imaging spectroscopy of loops at various temperature • Numerical simulations of non-linearly developed ballooning instability under solar coronal condition (3-D)

  22. LDEフレアにおけるエネルギーとプラズマの供給LDEフレアにおけるエネルギーとプラズマの供給 柴崎清登 （NRO)

  23. LDEフレアにおけるエネルギーとプラズマ供給 • LDEフレア • 継続時間、温度、RAY構造、Inflow(YOHKOH, SoHO/LASCO) • 磁気再結合シナリオ • Inflow によるエネルギーとプラズマの供給 • 継続時間と温度 • 高ベータ崩壊シナリオとの関係

  24. LDEフレア • プロミネンス崩壊 / CME, Two ribbon flare • 継続時間：数時間～1日 • 温度：８百万度、一定 • RAY構造：YOHKOH／SXT • Inflow • RAY構造に沿った下降流 (YOHKOH/SXT) • 上空コロナでの下降流 (SoHO/LASCO)

  25. Inflowによるエネルギーとプラズマの供給 • 位置エネルギー ⇒運動エネルギー ⇒熱エネルギー 　　　　mpgoRo h　　　　　　　　　　　　　h • T=　―――　 ―― T6=7.7 × ―― 3kB h+1 h+1 • プロミネンスの質量 ： 位置エネルギー 2×1015ｇ ～ 4×1030erg

  26. 高ベータ崩壊シナリオとの関係 • プロミネンス上昇 • 上空のアーケード磁場に衝突 • バルーニング（櫛状のfingers） • Fingersの上昇　：　RAY構造 • 上昇しきれなかったプラズマの下降 LASCO: inflow & SXT: inflow • 位置エネルギーの解放とプラズマの供給 　　長時間（LDE),一定温度（８MK)のプラズマ供給

More Related