Helical magnetic fields in filaments
Helical magnetic fields in filaments
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DOI：
10.1007/bf00670732
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发表时间：
1994-11
期刊：
影响因子：
2.8
通讯作者：
D. Rust;A. Kumar
中科院分区：
文献类型：
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作者：
D. Rust;A. Kumar
无论是偶数还是奇数太阳活动周，在北方半球中高纬度地区，右旋螺旋状暗条占主导地位，而在南半球，左旋螺旋状暗条占主导地位。最近的这一发现促使人们重新审视过去对磁场的测量。这一重新检验表明，鲁斯特（1967）在根据基彭哈恩-施吕特模型解释太阳活动20周的测量结果时，以及勒罗伊、博姆登和萨哈尔-布雷肖（1984）在根据库柏鲁斯-拉杜模型解释太阳活动21周的测量结果时，都被螺旋度的全球格局所误导。虽然原始的磁场测量结果是一致的新结果螺旋形磁场的灯丝，没有一个著名的类的二维模型可以产生适当的轴向磁场方向和观察到的模式的螺旋度。似乎需要一种全球性的、地下的速度模式，在出现之前将场扭曲为细丝。本文提出了一个与对丝场的新认识相一致的扭磁绳模型。该模型基于静磁方程的常数-α解，其中电流密度j（r）=αB（r）。模型灯丝的尺寸与观测结果基本一致。如果长度小于140 000 km到1，400 000 km（取决于α的值），则它是稳定的。该模型还提供了一个新的解释喷发的连续性和携带的物质的起源。
For both even and odd-numbered solar cycles, right-hand heliform filaments predominate at middle and high latitudes in the northern hemisphere while left-handed ones predominate in the south. This recent discovery has prompted a re-examination of past measurements of magnetic fields in prominences. This re-examination indicates that Rust (1967), in his interpretation of solar cycle 20 measurements in terms of the Kippenhahn-Schlüter model, and Leroy, Bommier, and Sahal-Bréchot (1984), in their interpretation of solar cycle 21 measurements in terms of the Kuperus-Raadu model were both misled by the global pattern of helicity. While the original magnetic field measurements are consistent with the new results about heliform magnetic fields in filaments, neither of the well-known classes of two-dimensional models can produce both the proper axial field direction and the observed pattern of helicity. A global, subsurface velocity pattern that would twist the fields before emergence as filaments seems to be required. In this paper a twisted-flux-rope model consistent with the new understanding of filament fields is presented. The model is based on a constant-αsolution of the magnetostatic equations, where electric current densityj(r) =αB(r). The model filament has dimensions in general agreement with observations. It is shown to be stable if the length is less than 140 000 km to 1,400 000 km, depending on the value ofα. The model also provides a new explanation of eruptive prominences and for the origin of the entrained material.