Relation between magnetospheric state parameters and the occurrence of plasma depletion events in the nighttime midlatitude F region
Relation between magnetospheric state parameters and the occurrence of plasma depletion events in the nighttime midlatitude F region
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DOI：
10.1029/2010ja015521
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发表时间：
2011-04
影响因子：
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通讯作者：
I. Seker;S. Fung;J. Mathews
中科院分区：
文献类型：
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作者：
I. Seker;S. Fung;J. Mathews
[1]使用全天成像仪的研究揭示了夜间中纬度F区存在各种电离层不规则性。其中最普遍和众所周知的是中尺度行进电离层扰动(MSTID)，通常在地磁活动较低时发生，以及在地磁活动较高时经常观察到的中纬度扩展F羽流。使用不同仪器的几项研究已经观察到地磁活动与MSTIDs和中纬度羽流的出现率之间分别存在反向和正向关系；然而，大多数研究只关注MSTIDs，并且只使用Kp来表征地磁活动。为了了解这两种关系的根本原因并区分MSTID和羽流，使用多个磁层状态参数更好地表征MSTID和羽流的发生是很有启发性的。在这里，我们统计比较了多个地磁驱动和响应参数(如Kp、AE、DST和太阳风参数)与2003年至2008年期间使用阿雷西博天文台的全天成像仪观测到的夜间MSTID和羽流的出现率。我们还给出了AO的MSTID和羽流的季节和年度变化。结果不仅使我们能够更好地区分MSTID和羽流，而且进一步阐明了中纬度F区夜间发生的这两种不同现象的产生机制和电动力学。
[1] Studies using all-sky imagers have revealed the presence of various ionospheric irregularities in the nighttime midlatitude F region. The most prevalent and well known of these are the medium-scale traveling ionospheric disturbances (MSTIDs) that usually occur when the geomagnetic activity is low and midlatitude spread F plumes that are often observed when the geomagnetic activity is high. The inverse and direct relations between geomagnetic activity and the occurrence rate of MSTIDs and midlatitude plumes, respectively, have been observed by several studies using different instruments; however, most of them focus on MSTIDs only and use only Kp to characterize geomagnetic activity. In order to understand the underlying causes of these two relations and to distinguish between MSTIDs and plumes, it is illuminating to better characterize the occurrence of MSTIDs and plumes using multiple magnetospheric state parameters. Here we statistically compare multiple geomagnetic driver and response parameters (such as Kp, AE, Dst, and solar wind parameters) with the occurrence rates of nighttime MSTIDs and plumes observed using an all-sky imager at Arecibo Observatory (AO) between 2003 and 2008. We also present seasonal and annual variations of MSTIDs and plumes at AO. The results not only allow us to better distinguish MSTIDs and plumes, but also to shed further light on the generation mechanism and electrodynamics of these two different phenomena occurring at nighttime in the midlatitude F region.