中纬度夏季夜间异常(midlatitude summer nighttime anomaly,MSNA)区域内的总电子含量(total electron content,TEC)的日变特性存在季节性差异,能否有效描述MSNA的特征是检验电离层TEC经验模型精度的关键指标之一。针对MSNA现象,提出了...中纬度夏季夜间异常(midlatitude summer nighttime anomaly,MSNA)区域内的总电子含量(total electron content,TEC)的日变特性存在季节性差异,能否有效描述MSNA的特征是检验电离层TEC经验模型精度的关键指标之一。针对MSNA现象,提出了一种适合MSNA区域的单站电离层TEC经验模型,命名为SSM-T2(single station model type2)模型;以位于MSNA区域内的南极半岛上的奥伊金斯站(ohi3)为例,验证了该模型的有效性。SSM-T2模型由3部分组成,分别是TEC日变化分量、季节变化分量和随太阳活动分量,模型中的系数由非线性最小二乘拟合得到。在南极半岛的ohi3站上,模型拟合测试结果表明,SSM-T2-ohi3模型与建模数据GPS-TEC拟合得很好,较好地描述了MSNA现象。通过模型对比分析发现,在外推时间点上,SSM-T2-ohi3与CODE GIMs、SSM-month模型符合得很好,能有效描述MSNA的特征,具有较好的预测能力,且总体上优于IRI2016模型。展开更多
The fundamental problem of ionospheric physics lies in understanding and modeling the ionosphere’s dependence on solar activity. This challenge encompasses such as Variables across Solar Cycles, Response to Solar Fla...The fundamental problem of ionospheric physics lies in understanding and modeling the ionosphere’s dependence on solar activity. This challenge encompasses such as Variables across Solar Cycles, Response to Solar Flares and CMEs, Daily and Seasonal Effects, Spatial Variability and long term prediction models. This dependency on solar activity helps provide information that is fundamental to comprehend the changes in the ionosphere and its processes. In this work, the ionospheric critical frequency foF2 and electron density are applied to characterize large-scale ionosphere responses during the 2015 geomagnetic storm. Using data from the International Reference Ionosphere (IRI-2016 model), an empirical standard model of the Ionosphere, this work tries to construct a correspondence between the solar activity and the change in the Ionosphere’s characteristics across three different stations at different altitudes. It has been observed that the electron density decreases from (1.098E + 12 to 7.844E + 11) for low latitude, (6.358E + 11 to 3.650E + 11.) for mid latitude and (4.765E + 11 to 2.740E + 11) for high latitude on the day of the solar event. A similar decrease in foF2 by 40% - 70% can also be seen for the three different stations on the geomagnetic storm day.展开更多
文摘中纬度夏季夜间异常(midlatitude summer nighttime anomaly,MSNA)区域内的总电子含量(total electron content,TEC)的日变特性存在季节性差异,能否有效描述MSNA的特征是检验电离层TEC经验模型精度的关键指标之一。针对MSNA现象,提出了一种适合MSNA区域的单站电离层TEC经验模型,命名为SSM-T2(single station model type2)模型;以位于MSNA区域内的南极半岛上的奥伊金斯站(ohi3)为例,验证了该模型的有效性。SSM-T2模型由3部分组成,分别是TEC日变化分量、季节变化分量和随太阳活动分量,模型中的系数由非线性最小二乘拟合得到。在南极半岛的ohi3站上,模型拟合测试结果表明,SSM-T2-ohi3模型与建模数据GPS-TEC拟合得很好,较好地描述了MSNA现象。通过模型对比分析发现,在外推时间点上,SSM-T2-ohi3与CODE GIMs、SSM-month模型符合得很好,能有效描述MSNA的特征,具有较好的预测能力,且总体上优于IRI2016模型。
文摘The fundamental problem of ionospheric physics lies in understanding and modeling the ionosphere’s dependence on solar activity. This challenge encompasses such as Variables across Solar Cycles, Response to Solar Flares and CMEs, Daily and Seasonal Effects, Spatial Variability and long term prediction models. This dependency on solar activity helps provide information that is fundamental to comprehend the changes in the ionosphere and its processes. In this work, the ionospheric critical frequency foF2 and electron density are applied to characterize large-scale ionosphere responses during the 2015 geomagnetic storm. Using data from the International Reference Ionosphere (IRI-2016 model), an empirical standard model of the Ionosphere, this work tries to construct a correspondence between the solar activity and the change in the Ionosphere’s characteristics across three different stations at different altitudes. It has been observed that the electron density decreases from (1.098E + 12 to 7.844E + 11) for low latitude, (6.358E + 11 to 3.650E + 11.) for mid latitude and (4.765E + 11 to 2.740E + 11) for high latitude on the day of the solar event. A similar decrease in foF2 by 40% - 70% can also be seen for the three different stations on the geomagnetic storm day.
