On the formation of postnoon auroral bright spots during weak substorm activity

doi:10.1016/j.asr.2023.12.058

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	On the formation of postnoon auroral bright spots during weak substorm activity
	Zhou, Su 5; Cai YZ(蔡永志)2,3,4; Ou, Ping 1; Zhu, Lin 1; Wu, Dan 1
刊名	ADVANCES IN SPACE RESEARCH
	2024-03-15
卷号	73 期号:6 页码:3087-3097
关键词	Postnoon auroral spots Electron acceleration Ionospheric convection Substorm activity
ISSN号	0273-1177
DOI	10.1016/j.asr.2023.12.058
产权排序	第3完成单位
文献子类	Article
英文摘要	Postnoon auroral bright spots occurring around 15:00 magnetic local time (MLT) are typically caused by monoenergetic electrons accelerated by quasi-static electric field. In this study, we conduct an analysis of two special auroral spots observed by the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) onboard the Defense Meteorological Satellite Program (DMSP) spacecraft. The first bright spot, observed on 05 June 2010, appears as a south-north aligned arc, while the second case, observed on 19 August 2005, takes the form of a circular patch. They both occurred at the equatorward edge of and are connected to the discrete aurora in the auroral oval. Particle measurements indicate that these two postnoon spots are primarily produced by precipitating electrons experiencing an acceleration process by quasi-static electric field. The average energy and integrated energy flux for the two cases are approximately 1.4 keV (1.5 keV) and 2.3 x 10(12) (1.1 x 10(12)) eV/(cm(2) s sr). It is suggested that the precipitating particles associated with the two cases originate from the boundary plasma sheet located poleward of the central plasma sheet. During the occurrences, the interplanetary magnetic field (IMF) B-y was nearly zero, while the IMF B-z was slightly negative, with values above -3 nT. Additionally, the geomagnetic AL index decreased to -160 and -200 nT, respectively. This indicates a potential relationship between the postnoon auroral spots and week substorm activities. Surprisingly, significant ion flow velocity was found to be nearly orientated with the postnoon spots. This suggests that the convection transports plenty of plasma along the south-north direction, offering sufficient particles for the formation of the postnoon auroral bright spots. (c) 2023 COSPAR. Published by Elsevier B.V. All rights reserved.
学科主题	天文学
URL标识	查看原文
出版地	125 London Wall, London, ENGLAND
资助项目	Guizhou Science and Technology Plan from Guizhou Provincial Department of Science and Technology; Guizhou Provincial Department of Science and Technology
WOS关键词	INTERPLANETARY MAGNETIC-FIELD ; BOUNDARY-LAYER ; LOW-ALTITUDE ; PRECIPITATION ; CONVECTION ; EXCITATION ; STREAMERS
WOS研究方向	Engineering ; Astronomy & Astrophysics ; Geology ; Meteorology & Atmospheric Sciences
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:001180602700001
资助机构	Guizhou Science and Technology Plan from Guizhou Provincial Department of Science and Technology[QKHJC-ZK[2022]YB015] ; Guizhou Provincial Department of Science and Technology
内容类型	期刊论文
版本	出版稿
源URL	[http://ir.ynao.ac.cn/handle/114a53/26512]
专题	云南天文台_丽江天文观测站（南方基地）
作者单位	1.School of Electronics and Information Engineering, Guiyang University, Guiyang, China; 2.Yunnan Observatories, Chinese Academy of Sciences, Kunming, China; 3.Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming, China; 4.International Centre of Supernovae, Yunnan Key Laboratory, Kunming, China 5.School of Science, Guiyang University, Guiyang, China;
推荐引用方式 GB/T 7714	Zhou, Su,Cai YZ,Ou, Ping,et al. On the formation of postnoon auroral bright spots during weak substorm activity[J]. ADVANCES IN SPACE RESEARCH,2024,73(6):3087-3097.
APA	Zhou, Su,蔡永志,Ou, Ping,Zhu, Lin,&Wu, Dan.(2024).On the formation of postnoon auroral bright spots during weak substorm activity.ADVANCES IN SPACE RESEARCH,73(6),3087-3097.
MLA	Zhou, Su,et al."On the formation of postnoon auroral bright spots during weak substorm activity".ADVANCES IN SPACE RESEARCH 73.6(2024):3087-3097.