平流层突然增温期间东亚扇区电离层赤道异常峰区扰动研究

The equatorial ionospheric anomaly (EIA) is the most important ionospheric structure that strongly controls the ionospheric behavior in the low latitude region. The study for the EIA can reveal the dynamic and electrodynamic processes in low latitude ionosphere. It is helpful for understanding the ionospheric phenomenon in low latitude and its physical mechanism. So, the variation of EIA has always been the one of the hottest topics in ionospheric field. Recent years, some ionospheric scientists focus their attention on the connection between the sudden stratospheric warming（SSW）in polar region and the ionospheric variation in low latitude. For example, the connection between the enhanced planetary waves or lunar tides in low atmosphere during SSW period and the planetary period scale variations in EIA region, the longitudinal dependence of ionospheric response in EIA region to SSW event. Based on the ionospheric data, geomagnetic data from ground or satellite observation, the morphological features of the EIA in East-Asia sector will be studied. Then, the characteristics of the variation of the EIA in both northern and southern hemisphere in East-Asia sector during intense SSW events will be studied, including the morphology, strength, and its connection with the variation of the low atmosphere. Through the study of the variation of EIA between East-Asia and American sectors during SSW period, the longitudinal dependence of the ionospheric response of EIA to SSW events will be studied, and the factors or physical processes to control the variation of EIA due to SSW will be revealed.

电离层赤道异常峰（EIA）是低纬电离层最重要的结构，其变化强烈影响着低纬度地区电离层状态。针对电离层EIA的研究可揭示低纬度电离层的动力学、电动力学过程，对理解该区域的电离层现象和物理过程是有帮助的，始终是电离层物理领域重点研究区域。近些年来，平流层突然增温（SSW）期间低纬电离层的形态和响应过程是电离层研究的热点之一，重点关注内容包括SSW期间盛行的低层大气行星波或者月潮与低纬电离层变化的关系，低纬电离层对SSW响应的经度依赖性等。本研究拟通过对基于地基、星基电离层密度参量，地磁参量等观测数据的分析，研究东亚扇区EIA的背景形态特征；在此基础上，研究SSW期间东亚扇区南北电离层EIA的扰动形态、强度，以及与低层大气扰动的关系；通过中美两扇区电离层EIA在SSW事件期间的形态特点，研究SSW期间电离层EIA扰动的经度差异，明晰SSW期间控制电离层EIA变化的物理过程与要素。

电离层赤道异常峰（EIA）是低纬电离层最重要的结构，其变化强烈影响着低纬度地区电离层状态。针对电离层EIA的研究可揭示低纬度电离层的动力学、电动力学过程，对理解该区域的电离层现象和物理过程是有帮助的，始终是电离层物理领域重点研究区域。本课题通过对基于地基、星基电离层密度参量，地磁参量等观测数据的分析，研究东亚和美洲扇区EIA的背景形态特征，发现两个区域的EIA存在着系统性的变化，东亚扇区EIA强度要强于美洲扇区，但EIA位置的季节变化弱于美洲扇区；本课题重点研究了SSW期间东亚和美洲扇区电离层EIA的扰动形态、强度的变化特点，发现SSW期间低纬电离层相关参量存在着准16日的周期性变化，这些周期性变化可以达到830千米的高度，此外，发现SSW期间电离层低纬度地区存在着半日月潮特征调制的扰动，这类扰动在美洲扇区要明显强于东亚扇区，研究发现有多种因素和过程影响到SSW期间低纬度地区电离层的响应，如赤道喷泉效应，电离层背景参量，地磁场结构和热层风场形态。