Bibliography

Local Persistent Ionospheric Positive Responses to the Geomagnetic Storm in August 2018 Using BDS-GEO Satellites over Low-Latitude Regions in Eastern Hemisphere

We present the ionospheric disturbance responses over low-latitude regions by using total electron content from Geostationary Earth Orbit (GEO) satellites of the BeiDou Navigation Satellite System (BDS), ionosonde data and Swarm satellite data, during the geomagnetic storm in August 2018. The results show that a prominent total electron content (TEC) enhancement over low-latitude regions is observed during the main phase of the storm. There is a persistent TEC increase lasting for about 1–2 days and a moderately positive disturbance response during the recovery phase on 27–28 August, which distinguishes from the general performance of ionospheric TEC in the previous storms. We also find that this phenomenon is a unique local-area disturbance of the ionosphere during the recovery phase of the storm. The enhanced foF2 and hmF2 of the ionospheric F2 layer is observed by SANYA and LEARMONTH ionosonde stations during the recovery phase. The electron density from Swarm satellites shows a strong equatorial ionization anomaly (EIA) crest over the low-latitude area during the main phase of storm, which is simultaneous with the uplift of the ionospheric F2 layer from the SANYA ionosonde. Meanwhile, the thermosphere O/N2 ratio shows a local increase on 27–28 August over low-latitude regions. From the above results, this study suggests that the uplift of F layer height and the enhanced O/N2 ratio are possibly main factors causing the local-area positive disturbance responses during the recovery phase of the storm in August 2018.

Tang, Jun; Gao, Xin; Yang, Dengpan; Zhong, Zhengyu; Huo, Xingliang; Wu, Xuequn;

Published by: Remote Sensing      Published on: jan

YEAR: 2022     DOI: 10.3390/rs14092272

BDS-GEO; differential code biases; geomagnetic storm; Ionospheric disturbance; TEC

The nighttime ionospheric response and occurrence of equatorial plasma irregularities during geomagnetic storms: a case study

Recent studies revealed that the long-lasting daytime ionospheric enhancements of Total Electron Content (TEC) were sometimes observed in the Asian sector during the recovery phase of geomagnetic storms (e.g., Lei (J Geophys Res Space Phys 123: 3217–3232, 2018), Li (J Geophys Res Space Phys 125: e2020JA028238, 2020). However, they focused only on the dayside ionosphere, and no dedicated studies have been performed to investigate the nighttime ionospheric behavior during such kinds of storm recovery phases. In this study, we focused on two geomagnetic storms that happened on 7–8 September 2017 and 25–26 August 2018, which showed the prominent daytime TEC enhancements in the Asian sector during their recovery phases, to explore the nighttime large-scale ionospheric responses as well as the small-scale Equatorial Plasma Irregularities (EPIs). It is found that during the September 2017 storm recovery phase, the nighttime ionosphere in the American sector is largely depressed, which is similar to the daytime ionospheric response in the same longitude sector; while in the Asian sector, only a small TEC increase is observed at nighttime, which is much weaker than the prominent daytime TEC enhancement in this longitude sector. During the recovery phase of the August 2018 storm, a slight TEC increase is observed on the night side at all longitudes, which is also weaker than the prominent daytime TEC enhancement. For the small-scale EPIs, they are enhanced and extended to higher latitudes during the main phase of both storms. However, during the recovery phases of the first storm, the EPIs are largely enhanced and suppressed in the Asian and American sectors, respectively, while no prominent nighttime EPIs are observed during the second storm recovery phase. The clear north–south asymmetry of equatorial ionization anomaly crests during the second storm should be responsible for the suppression of EPIs during this storm. In addition, our results also suggest that the dusk side ionospheric response could be affected by the daytime ionospheric plasma density/TEC variations during the recovery phase of geomagnetic storms, which further modulates the vertical plasma drift and plasma gradient. As a result, the growth rate of post-sunset EPIs will be enhanced or inhibited.

Wan, Xin; Xiong, Chao; Gao, Shunzu; Huang, Fuqing; Liu, Yiwen; Aa, Ercha; Yin, Fan; Cai, Hongtao;

Published by: Satellite Navigation      Published on: nov

YEAR: 2021     DOI: 10.1186/s43020-021-00055-x

Equatorial plasma irregularity; Geomagneitc storm; Ionospheric response; longitudinal variations; Storm recovery phase

Ionospheric response to the 17 March and 22 June 2015 geomagnetic storms over Wuhan region using GNSS-based tomographic technique

By using the data of GNSS (Global Navigation Satellite System) observation from Crustal Movement Observation Network of China (CMONOC), ionospheric electron density (IED) distributions reconstructed by using computerized ionospheric tomography (CIT) technique are used to investigate the ionospheric storm effects over Wuhan region during 17 March and 22 June 2015 geomagnetic storm periods. F-region critical frequency (foF2) at Wuhan ionosonde station shows an obvious decrease during recovery phase of the St. Patrick’s Day geomagnetic storm. Moreover, tomographic results present that the decrease in electron density begins at 12:00 UT on 17 March during the storm main phase. Also, foF2 shows a long-lasting negative storm effect during the recovery phase of the 22 June 2015 geomagnetic storm. Electron density chromatography presents the evident decrease during the storm day in accordance with the ionosonde observation. These ionospheric negative storm effects are probably associated with changes of chemical composition, PPEF and DDEF from high latitudes.

Feng, Jian; Zhou, Yufeng; Zhou, Yan; Gao, Shuaihe; Zhou, Chen; Tang, Qiong; Liu, Yi;

Published by: Advances in Space Research      Published on: jan

YEAR: 2021     DOI: 10.1016/j.asr.2020.10.008

Ionospheric electron density distributions; ionospheric storm effects; Multiplication algebraic reconstruction technique

Statistical structure of nighttime O2 aurora from SABER and its dependence on geomagnetic and solar activities in winter

O 2 aurora is one kind of important molecular aurorae that is not fully understood yet. It is hard to be investigated due to the contamination by nightglow. In this work, we studied O 2

Gao, Hong; Xu, JiYao; Chen, Guang-Ming; Zhu, Yajun; Liu, Weijun; Wang, Chi;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2020     DOI: 10.1029/2020JA028302

Prediction and variation of the auroral oval boundary based on a deep learning model and space physical parameters

The auroral oval boundary represents an important physical process with implications for the ionosphere and magnetosphere. An automatic auroral oval boundary prediction method

Han, Yiyuan; Han, Bing; Hu, Zejun; Gao, Xinbo; Zhang, Lixia; Yang, Huigen; Li, Bin;

Published by: Nonlinear Processes in Geophysics      Published on:

YEAR: 2020     DOI: 10.5194/npg-27-11-2020

Auroral Oval Boundary Modeling Based on Deep Learning Method

Research on the location of the auroral oval is important to understand the coupling processes of the Sun-Earth system. The equatorward boundary and poleward boundary of the auroral oval are significant parameters of the auroral oval location. Thus auroral oval boundary modeling is an efficient way to study the location of auroral oval. As the location of the auroral oval boundary is subject to a variety of geomagnetic factors, there are some limitations on traditional methods, which express the auroral oval boundary as a function of only one or several geomagnetic activity index. Deep learning method is used in this paper to learn the essential features of the inputs, which are a large number of geomagnetic parameters and the former locations of aurora boundary. Furthermore, a model is established to forecast the location of the auroral oval boundary. The experiment results show that our method can model and forecast the boundary of aurora oval efficiently on the data set obtained from Ultraviolet Imager (UVI) on Polar satellite and OMNI database on NASA.

Han, Bing; Gao, Xinbo; Liu, Hui; Wang, Ping;

Published by:       Published on:

YEAR: 2015     DOI: 10.1007/978-3-319-23862-310.1007/978-3-319-23862-3_10

Longitudinal distribution of O2 nightglow brightness observed by TIEMD/SABER satellite

Gao, Hong; Nee, JanBai; Chen, GuangMing;

Published by: Science China Technological Sciences      Published on: Jan-05-2012

YEAR: 2012     DOI: 10.1007/s11431-012-4802-0

Global distributions of OH and O2 (1.27 μm) nightglow emissions observed by TIMED satellite

Gao, Hong; Xu, JiYao; Chen, GuangMing; Yuan, Wei; Beletsky, A.;

Published by: Science China Technological Sciences      Published on: Jan-02-2011

YEAR: 2011     DOI: 10.1007/s11431-010-4236-5

Global distributions of OH and O2 (1.27 $\mu$m) nightglow emissions observed by TIMED satellite

In order to investigate the global distributions of temporal variations of OH and O 2 nightglow emissions, we statistically analyzed their variations with altitude, local time, and season

Gao, Hong; Xu, JiYao; Chen, GuangMing; Yuan, Wei; Beletsky, AB;

Published by: Science China Technological Sciences      Published on:

YEAR: 2011     DOI: https://doi.org/10.1007/s11431-010-4236-5