Steady magnetospheric convection selection criteria: Implications of global SuperDARN convection measurements
Steady magnetospheric convection selection criteria: Implications of global SuperDARN convection measurements
复制标题
稳定磁层对流选择标准：全球 SuperDARN 对流测量的影响
DOI：
10.1029/2008gl033671
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发表时间：
2008
影响因子：
5.2
通讯作者：
R. McPherron
中科院分区：
文献类型：
--
作者：
K. McWilliams;J. B. Pfeifer;R. McPherron
定量的定义已经发展到检测稳定的磁层对流（SMC）的间隔，但这些方法是基于对流的代理人，如极光电喷流（AE）指数。第一次，观测电离层对流在全球范围内进行了研究，在确定为稳定的磁层对流事件的间隔。SMC发生和SuperDARN跨极电压表现出很强的季节性偏差，这被认为是由于电离层电导率的季节性变化。在冬季和夏季等效AE值对应于类似的电射流电流强度，但不同的对流水平。使用恒定AE阈值选择的事件对应于增强的对流，但高于可变阈值。这项SuperDARN研究是利用对流观测提高SMC事件选择可靠性的第一步。我们提出了一个新的可变AE截止函数，以减少SMC选择电离层电导率的季节依赖性。
Quantitative definitions have been developed to detect intervals of steady magnetospheric convection (SMC), but these methods are based only on proxies of convection, such as the Auroral Electrojet (AE) indices. For the first time, observations of ionospheric convection on a global scale are studied during intervals identified as steady magnetospheric convection events. The SMC occurrence and SuperDARN transpolar voltage exhibit a strong seasonal bias, which is believed to be due to the seasonal variation of ionospheric conductivity. Equivalent AE values in winter and summer correspond to similar electrojet current strengths but to different levels of convection. Events selected using a constant AE threshold correspond to enhanced convection but above a variable threshold. This SuperDARN study is the first step in improving the reliability of SMC event selection by using convection observations. We present a new variable AE cutoff function to reduce the seasonal dependence of SMC selection on ionospheric conductivity.