Superposed epoch analysis of the ionospheric convection evolution during substorms : onset latitude dependence
Superposed epoch analysis of the ionospheric convection evolution during substorms : onset latitude dependence
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亚暴期间电离层对流演化的叠加历元分析：爆发纬度依赖性
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
T. Yeoman
中科院分区：
文献类型：
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作者：
A. Grocott;J. Wild;S. Milan;T. Yeoman
利用超级双极光雷达网（SuperDARN）的观测资料，研究了磁层亚暴对电离层对流的响应。使用磁层顶-极光全球探测（IMAGE）航天器成像仪上的远紫外线（FUV）仪器识别亚暴，然后根据其开始的磁纬度进行雅阁。叠加历元分析的电离层对流模式为每个发病纬度箱，然后进行使用雷达数据的间隔60分钟发病前90分钟后。结果发现，较低的起始纬度的亚暴与一般更多的增强对流比高纬度的亚暴，虽然他们遭受一个显着的本地化减少的流量在午夜部门在expan-锡永阶段。高纬度亚暴伴随着亚暴爆发后夜侧对流的显著和快速增加，所有爆发纬度箱在进入扩张阶段60分钟时显示出比爆发值增强。对同时发生的极光演化的初步研究表明，亚暴开始后气流减少的持续时间取决于扩张阶段极光的强度和持续时间及其相关的电导率增强。
Using data from the Super Dual Auroral Radar Network (SuperDARN) we investigate the ionospheric con- vection response to magnetospheric substorms. Substorms were identified using the Far Ultraviolet (FUV) instrument on board the Imager for Magnetopause-to-Aurora Global Ex- ploration (IMAGE) spacecraft, and were then binned accord- ing to the magnetic latitude of their onset. A superposed epoch analysis of the ionospheric convection patterns for each onset-latitude bin was then performed using radar data for the interval 60 min before onset to 90 min after. It is found that lower onset-latitude substorms are associated with generally more enhanced convection than the higher latitude substorms, although they suffer from a significant localised reduction of the flow in the midnight sector during the expan- sion phase. Higher-latitude substorms are associated with a significant and rapid increase in the nightside convection fol- lowing substorm onset, with all onset-latitude bins showing an enhancement over onset values by 60 min into the ex- pansion phase. A rudimentary inspection of the concurrent auroral evolution suggests that the duration of the flow reduc- tion following substorm onset is dependent on the strength and duration of the expansion phase aurora and its associated conductivity enhancement.
影响因子：
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作者：
J. Wild;A. Grocott
通讯作者：
J. Wild;A. Grocott