基于太陽爆發(fā)災(zāi)變模型的數(shù)值實驗
發(fā)布時間：2019-05-10 05:06
【摘要】：我們在Isenberg等人1993年發(fā)展的災(zāi)變模型的基礎(chǔ)上,在接近真實的日冕環(huán)境的條件下,通過數(shù)值實驗,對磁通量繩的平衡高度對背景磁場變化的響應(yīng)開展了研究,利用NIRVANA程序進行了計算。我們的工作中的日冕等離子密度分布采用了一個半經(jīng)驗的模型,模擬中包含了物理耗散。我們考察了磁通量繩的平衡位置及其演化特征,參考半徑的變化對磁通量繩平衡位置的影響,磁通量繩內(nèi)部平衡的性質(zhì)以及在磁通量繩失去平衡之后一段時間內(nèi)的的動力學(xué)與運動學(xué)特征。結(jié)果表明:數(shù)值實驗中得到的磁通量繩的平衡態(tài)位置與Isenberg等人的理論結(jié)果有一點微小的偏離,但是演化特征基本一致,在臨界點處系統(tǒng)迅速失去平衡,向爆發(fā)態(tài)演化;參考半徑的變化對磁通量繩平衡位置的影響與災(zāi)變模型給出的結(jié)果基本一致;磁通量繩在隨著宏觀磁結(jié)構(gòu)演化的同時,還通過自身的調(diào)節(jié)達到內(nèi)部平衡,當(dāng)磁通量繩的內(nèi)部和外部平衡都實現(xiàn)之后,系統(tǒng)整體也就達到了平衡狀態(tài);在爆發(fā)態(tài)下,磁通量繩的運動特征與Lin-Forbes模型和觀測給出的結(jié)果一致,并且在通量繩的前沿有快模激波出現(xiàn);由于數(shù)值實驗中包括了耗散,爆發(fā)過程中的磁能向其它形式的能量的轉(zhuǎn)換非常明顯。
[Abstract]:On the basis of the catastrophe model developed by Isenberg et al in 1993, and under the condition of approaching the real coronal environment, the response of the equilibrium height of magnetic flux rope to the change of background magnetic field is studied by numerical experiments. The calculation is carried out by NIRVANA program. A semi-empirical model is used for the distribution of coronal plasma density in our work, and physical dissipation is included in the simulation. We investigate the equilibrium position and evolution characteristics of the magnetic flux rope, and the influence of the change of the reference radius on the equilibrium position of the magnetic flux rope. The properties of the internal equilibrium of the magnetic flux rope and the dynamic and kinematic characteristics of the magnetic flux rope in the period after the loss of the balance of the magnetic flux rope. The results show that the equilibrium position of the magnetic flux rope obtained in the numerical experiment deviates slightly from the theoretical results of Isenberg et al., but the evolution characteristics are basically the same. The system loses its equilibrium rapidly at the critical point and evolves to the explosive state. The influence of the change of reference radius on the equilibrium position of magnetic flux rope is basically consistent with the results given by the catastrophe model. With the evolution of the macro magnetic structure, the magnetic flux rope also achieves the internal balance through its own adjustment. When the internal and external balance of the magnetic flux rope is realized, the system as a whole reaches the equilibrium state. In the explosive state, the motion characteristics of the magnetic flux rope are consistent with the Lin-Forbes model and the observed results, and there are fast mode shock waves at the front of the flux rope. Because dissipation is included in the numerical experiment, the conversion from magnetic energy to other forms of energy in the process of explosion is very obvious.
【學(xué)位授予單位】：中國科學(xué)院大學(xué)(中國科學(xué)院云南天文臺)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P182
本文編號：2473367
[Abstract]:On the basis of the catastrophe model developed by Isenberg et al in 1993, and under the condition of approaching the real coronal environment, the response of the equilibrium height of magnetic flux rope to the change of background magnetic field is studied by numerical experiments. The calculation is carried out by NIRVANA program. A semi-empirical model is used for the distribution of coronal plasma density in our work, and physical dissipation is included in the simulation. We investigate the equilibrium position and evolution characteristics of the magnetic flux rope, and the influence of the change of the reference radius on the equilibrium position of the magnetic flux rope. The properties of the internal equilibrium of the magnetic flux rope and the dynamic and kinematic characteristics of the magnetic flux rope in the period after the loss of the balance of the magnetic flux rope. The results show that the equilibrium position of the magnetic flux rope obtained in the numerical experiment deviates slightly from the theoretical results of Isenberg et al., but the evolution characteristics are basically the same. The system loses its equilibrium rapidly at the critical point and evolves to the explosive state. The influence of the change of reference radius on the equilibrium position of magnetic flux rope is basically consistent with the results given by the catastrophe model. With the evolution of the macro magnetic structure, the magnetic flux rope also achieves the internal balance through its own adjustment. When the internal and external balance of the magnetic flux rope is realized, the system as a whole reaches the equilibrium state. In the explosive state, the motion characteristics of the magnetic flux rope are consistent with the Lin-Forbes model and the observed results, and there are fast mode shock waves at the front of the flux rope. Because dissipation is included in the numerical experiment, the conversion from magnetic energy to other forms of energy in the process of explosion is very obvious.
【學(xué)位授予單位】：中國科學(xué)院大學(xué)(中國科學(xué)院云南天文臺)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P182
【參考文獻】
相關(guān)期刊論文 前1條
1 ;Energetics and Propagation of Coronal Mass Ejections in Different Plasma Environments[J];Chinese Journal of Astronomy and Astrophysics;2002年06期
，本文編號：2473367
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