Swarm Satellite Observations of the 21 August 2017 Solar Eclipse

IF 0.6 Q4 ASTRONOMY & ASTROPHYSICS

Journal of Astronomy and Space Sciences Pub Date : 2020-03-01 DOI:10.5140/JASS.2020.37.1.29

Fayrouz Hussien, E. Ghamry, A. Fathy, S. Mahrous

{"title":"Swarm Satellite Observations of the 21 August 2017 Solar Eclipse","authors":"Fayrouz Hussien, E. Ghamry, A. Fathy, S. Mahrous","doi":"10.5140/JASS.2020.37.1.29","DOIUrl":null,"url":null,"abstract":"On 21 August 2017, during 16:49 UT and 20:02 UT period, a total solar eclipse\n started. The totality shadow occurred over the United States in time between ~17:15 UT\n and ~18:47 UT. When the solar radiation is blocked by the moon, observations of the\n ionospheric parameters will be important in the space weather community. Fortunately,\n during this eclipse, two Swarm satellites (A and C) flied at about 445 km through lunar\n penumbra at local noon of United States in the upper ionosphere. In this work, we\n investigate the effect of the solar eclipse on electron density, slant total electron\n content (STEC) and electron temperature using data from Swarm mission over United\n States. We use calibrated measurements of plasma density and electron temperature. Our\n results indicate that: (1) the electron density and STEC have a significant depletion\n associated with the eclipse; which could be due to dominance of dissociative\n recombination over photoionization caused by the reduction of ionizing extreme\n ultraviolet (EUV) radiation during the eclipse time (2) the electron temperature\n decreases, compared with a reference day, by up to ~150 K; which could be due to the\n decrease in photoelectron heating from reduced photoionization.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":"129 1 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Astronomy and Space Sciences","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.5140/JASS.2020.37.1.29","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}

引用次数: 5

Abstract

On 21 August 2017, during 16:49 UT and 20:02 UT period, a total solar eclipse started. The totality shadow occurred over the United States in time between ~17:15 UT and ~18:47 UT. When the solar radiation is blocked by the moon, observations of the ionospheric parameters will be important in the space weather community. Fortunately, during this eclipse, two Swarm satellites (A and C) flied at about 445 km through lunar penumbra at local noon of United States in the upper ionosphere. In this work, we investigate the effect of the solar eclipse on electron density, slant total electron content (STEC) and electron temperature using data from Swarm mission over United States. We use calibrated measurements of plasma density and electron temperature. Our results indicate that: (1) the electron density and STEC have a significant depletion associated with the eclipse; which could be due to dominance of dissociative recombination over photoionization caused by the reduction of ionizing extreme ultraviolet (EUV) radiation during the eclipse time (2) the electron temperature decreases, compared with a reference day, by up to ~150 K; which could be due to the decrease in photoelectron heating from reduced photoionization.

查看原文本刊更多论文

2017年8月21日日食的群卫星观测

2017年8月21日，在16:49 UT和20:02 UT期间，日全食开始。日全食发生在世界时17:15 ~18:47之间。当太阳辐射被月球阻挡时，对电离层参数的观测在空间气象界将是重要的。幸运的是，在这次月食期间，两颗Swarm卫星(A和C)在美国当地中午在电离层上层飞越月球半影约445公里。在这项工作中，我们利用美国Swarm任务的数据研究了日食对电子密度、倾斜总电子含量(STEC)和电子温度的影响。我们使用校准的等离子体密度和电子温度测量。结果表明:(1)与日蚀相关的电子密度和STEC显著降低;这可能是由于在日食期间电离极紫外(EUV)辐射的减少导致解离重组比光电离更占优势。(2)与参考日相比，电子温度降低了约150 K;这可能是由于光电离减少导致的光电子加热减少。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Astronomy and Space Sciences ASTRONOMY & ASTROPHYSICS-

CiteScore

1.30

自引率

20.00%

发文量

审稿时长

12 weeks

期刊介绍： JASS aims for the promotion of global awareness and understanding of space science and related applications. Unlike other journals that focus either on space science or on space technologies, it intends to bridge the two communities of space science and technologies, by providing opportunities to exchange ideas and viewpoints in a single journal. Topics suitable for publication in JASS include researches in the following fields: space astronomy, solar physics, magnetospheric and ionospheric physics, cosmic ray, space weather, and planetary sciences; space instrumentation, satellite dynamics, geodesy, spacecraft control, and spacecraft navigation. However, the topics covered by JASS are not restricted to those mentioned above as the journal also encourages submission of research results in all other branches related to space science and technologies. Even though JASS was established on the heritage and achievements of the Korean space science community, it is now open to the worldwide community, while maintaining a high standard as a leading international journal. Hence, it solicits papers from the international community with a vision of global collaboration in the fields of space science and technologies.