地球与行星物理论评（中英文）2024，Vol.55Issue(5)：595-608,14.DOI:10.19975/j.dqyxx.2023-059
DEMETER卫星离子浓度表征的电离层顶部结构季节变化特征
Inner properties of seasonal topside ionospheric structures determined via DEMETER ion perturbations
摘要
Abstract
In this investigation,117 718 ionospheric perturbations with a space size t=20-300 s,but without a limit on amplitude(A),were automatically searched globally via software using ion density data measured by the Detection of Electromagnetic Emissions Transmitted from Earthquake Regions(DEMETER)satellite for approxi-mately six years.After eliminating 18 169 perturbations(PERs)that occurred in perturbed time(Kp ≥ 3)in order to avoid the global effects of geomagnetic storms,99 549 PERs were left.These PERs were divided into six groups with respect to local time and season,but only the summer and winter PERs were kept for good comparison.Each group of PERs was distributed on a map in terms of amplitude and space size.The distributions of all groups of plasma PERs showed that the equatorial ionization anomaly(E1A)structure developed well during the winter day-time.This structure is characterized by a low plasma PER density(Np)on both sides of the magnetic equator at low latitudes and a sudden enhancement of Np at a magnetic latitude of 15° at both sides of the magnetic latitudes.At the same time,this daytime anomaly was also clearly presented with a simultaneous enhancement in both Np and space size,even beyond 200 s along its boundary line.From the viewpoint of space size,there is a demarcation point,t=120 s;the occurrence probabilities of day PERs are always higher than those at night before this point,whereas this result is reversed after this point.Another key point is that large spatial-scale perturbations(t＞200 s)present their major significance during daytime,especially during summer daytime,probably due to ionization un-der strong sunlight.The WSA(Wedell Sea Anomaly)phenomenon shows a clear configuration at all times except on the summer day.The topside ionosphere remained calm during the day in summer,and no positive PERs with a magnitude of more than 50％or a negative magnitude of more than 100％occurred in this WSA area.In winter nighttime,this WSA structure was characterized by major large positive PERs with a magnitude of more than 100％.关键词
电离层结构/离子扰动/自动探测方法/变化特征Key words
ionospheric structures/ion perturbations/automatic detection method/inner property分类
地球科学引用本文复制引用
李美,阎泓竹,张永仙..DEMETER卫星离子浓度表征的电离层顶部结构季节变化特征[J].地球与行星物理论评（中英文）,2024,55(5):595-608,14.基金项目
This research was supported by the Center National d'Etudes Spatiales.It is based on observations using the plasma analyzer IAP embarked on by DEMETER.This work was supported by Special Expenses for Basic Scientific Research under Grant No.CEAIEF2022030206 and the National Natural Science Foundation of China(NSFC)under Grant No.41774084. （NSFC）
