Effects of the Ring Current Decay Rate on the Energy State of the Magnetosphere
Effects of the Ring Current Decay Rate on the Energy State of the Magnetosphere
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DOI：
10.1002/cjg2.1501
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发表时间：
2010-05
期刊：
影响因子：
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通讯作者：
Wen-yao Xu;A. Du
中科院分区：
文献类型：
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作者：
Wen-yao Xu;A. Du
地磁暴主要由环流引起，环流的衰减率是估算磁层能量收支和风暴预测的关键参数之一。本文提出了两个新的评估衰减率模型的标准：（1）E标准：风暴事件的总能量平衡，或整个事件过程中综合能量输入和输出之间的平衡； (2)L准则：较长时间间隔内的总能量平衡，或足够长的时间跨度内综合能量输入和输出之间的平衡。通过使用1998~2003年期间的44个选定风暴以及第23个太阳周期（1998~2008）长达11年的连续记录来检验九个衰减率模型。结果表明，模型 PA1978 和 XD2010 在所有研究事件中都表现出相当好的能量平衡，满足 E 准则。此外，这两个模型很好地满足了 L 准则，在重大风暴事件期间表现出增强的能量耗散和长期能量平衡。
Geomagnetic storms are mainly caused by the ring current, the decay rate of which is one of the key parameters for estimating energy budget of the magnetosphere and for storm prediction. Two new criterions are suggested in this paper for evaluating decay rate models: (1) the E-criterion: the total energy balance for a storm event, or balance between the integrated energy input and output during whole course of the event; (2) the L-criterion: the total energy balance for a long interval, or balance between the integrated energy input and output for a sufficiently long time span. Nine decay rate models are examined by using 44 selected storms during 1998~2003 and using an 11-year-long continuous record for the 23rd solar cycle (1998~2008). The results show that the models PA1978 and XD2010 show fairly good energy balance for all studied events, satisfying the E-criterion. In addition, the two models rather well satisfy the L-criterion, exhibiting enhanced energy dissipation during major storm events and long-term energy balance.