A new ionospheric storm scale based on TEC and foF2 statistics
A new ionospheric storm scale based on TEC and foF2 statistics
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DOI：
10.1002/2016sw001536
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发表时间：
2017-01
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影响因子：
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通讯作者：
M. Nishioka;T. Tsugawa;H. Jin;M. Ishii
中科院分区：
文献类型：
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作者：
M. Nishioka;T. Tsugawa;H. Jin;M. Ishii
在本文中，我们提出了 I 尺度，这是一种新的电离层风暴尺度，供世界各地的一般用户使用。利用 I 尺度，可以对任何季节、当地时间和地点的电离层风暴进行分类。由于电离层状况在很大程度上取决于太阳辐照度、磁层能量输入以及较低的大气活动等多种因素，因此很难规模化电离层风暴，而电离层风暴主要是由太阳和地磁活动引起的。本研究对日本从 1997 年到 2014 年 18 年的总电子含量 (TEC) 和 F2 层临界频率 (foF2) 进行了统计分析。通过使用统计标准差对每个百分比变化进行标准化，排除了 TEC 和 foF2 变异性的季节、当地时间和纬度依赖性。 I 尺度是通过将标准化数字的阈值设置为七个类别来定义的：I0、IP1、IP2、IP3、IN1、IN2 和 IN3。 I0代表安静状态，IP1（IN1）、IP2（IN2）和IP3（IN3）分别代表中度、强和严重的正（负）风暴。所提出的 I 尺度可用于其他位置，例如极地和赤道地区。据认为，所提出的 I 尺度可以成为一个标准化尺度，以帮助用户评估空间天气对其系统的影响。
In this paper, we propose the I‐scale, a new ionospheric storm scale for general users in various regions in the world. With the I‐scale, ionospheric storms can be classified at any season, local time, and location. Since the ionospheric condition largely depends on many factors such as solar irradiance, energy input from the magnetosphere, and lower atmospheric activity, it had been difficult to scale ionospheric storms, which are mainly caused by solar and geomagnetic activities. In this study, statistical analysis was carried out for total electron content (TEC) and F2 layer critical frequency (foF2) in Japan for 18 years from 1997 to 2014. Seasonal, local time, and latitudinal dependences of TEC and foF2 variabilities are excluded by normalizing each percentage variation using their statistical standard deviations. The I‐scale is defined by setting thresholds to the normalized numbers to seven categories: I0, IP1, IP2, IP3, IN1, IN2, and IN3. I0 represents a quiet state, and IP1 (IN1), IP2 (IN2), and IP3 (IN3) represent moderate, strong, and severe positive (negative) storms, respectively. The proposed I‐scale can be used for other locations, such as polar and equatorial regions. It is considered that the proposed I‐scale can be a standardized scale to help the users to assess the impact of space weather on their systems.