Chinese Sunspot Drawings and Their Digitization-(VII) Sunspot Penumbra to Umbra Area Ratio Using the Hand-Drawing Records from Yunnan Observatories | |
Hou, Jia-Wei3,4; Zeng, Shu-Guang3,4; Zheng, Sheng3,4; Luo, Xiao-Yu3,4; Deng LH(邓林华)2; Li, Yang-Yang3,4; Chen, Yan-Qing3,4; Lin, Gang-Hua1; Feng YL(冯永利)2; Tao JP(陶金萍)2 | |
刊名 | RESEARCH IN ASTRONOMY AND ASTROPHYSICS |
2022-09-01 | |
卷号 | 22期号:9 |
关键词 | (Sun:) sunspots Sun: photosphere Sun: activity techniques: image processing |
ISSN号 | 1674-4527 |
DOI | 10.1088/1674-4527/ac7f87 |
产权排序 | 第3完成单位 |
文献子类 | Article |
英文摘要 | The ratio of penumbral to umbra area of sunspots plays a crucial role in the solar physics fields, especially for understanding the origin and evolution of the solar activity cycle. By analyzing the recently digitized sunspot drawings observed from Yunnan Observatories (1957-2021), we investigate the long-term variation of the penumbral to umbra area ratio of sunspots. An automatic extraction method, based on the maximum between-class variance and the morphological discrimination, is used to accurately extract penumbra and umbra and to calculate the ratio over six solar cycles (cycle 19-24). The expected value of the ratio of penumbra to umbra area is found to be 6.63 +/- 0.98, and it does not exhibit any systematic variation with sunspot latitudes and phases. The average ratio fluctuates from 5 to 7.5 per year and the overall trend has decreased after 1999 compared to the previous one. The ratio of sunspot penumbra to umbra area satisfies the log-normal distribution, implying that its variation is related to the evolution of the photospheric magnetic field. Our results are consistent with previous works. |
学科主题 | 天文学 ; 太阳与太阳系 ; 太阳物理学 |
URL标识 | 查看原文 |
出版地 | 20A DATUN RD, CHAOYANG, BEIJING, 100012, PEOPLES R CHINA |
资助项目 | Chinese Academy of Sciences ; National Natural Science Foundation of China[U2031202] ; National Natural Science Foundation of China[U1731124] ; special foundation work of the Ministry of Science and Technology of China[2014FY120300] ; 13th Five-year Informatization Plan of Chinese Academy of Sciences[XXH13505-04] |
WOS关键词 | CURIOUS HISTORY |
WOS研究方向 | Astronomy & Astrophysics |
语种 | 英语 |
出版者 | NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES |
WOS记录号 | WOS:000840966600001 |
资助机构 | Chinese Academy of Sciences ; National Natural Science Foundation of China[U2031202, U1731124] ; special foundation work of the Ministry of Science and Technology of China[2014FY120300] ; 13th Five-year Informatization Plan of Chinese Academy of Sciences[XXH13505-04] |
内容类型 | 期刊论文 |
版本 | 出版稿 |
源URL | [http://ir.ynao.ac.cn/handle/114a53/25540] |
专题 | 云南天文台_太阳物理研究组 |
通讯作者 | Zeng, Shu-Guang |
作者单位 | 1.National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China 2.Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216, China; 3.College of Science, China Three Gorges University, Yichang 443002, China; 4.Center for Astronomy and Space Sciences, China Three Gorges University, Yichang 443002, China; zengshuguang19@163.com; |
推荐引用方式 GB/T 7714 | Hou, Jia-Wei,Zeng, Shu-Guang,Zheng, Sheng,et al. Chinese Sunspot Drawings and Their Digitization-(VII) Sunspot Penumbra to Umbra Area Ratio Using the Hand-Drawing Records from Yunnan Observatories[J]. RESEARCH IN ASTRONOMY AND ASTROPHYSICS,2022,22(9). |
APA | Hou, Jia-Wei.,Zeng, Shu-Guang.,Zheng, Sheng.,Luo, Xiao-Yu.,Deng LH.,...&Tao JP.(2022).Chinese Sunspot Drawings and Their Digitization-(VII) Sunspot Penumbra to Umbra Area Ratio Using the Hand-Drawing Records from Yunnan Observatories.RESEARCH IN ASTRONOMY AND ASTROPHYSICS,22(9). |
MLA | Hou, Jia-Wei,et al."Chinese Sunspot Drawings and Their Digitization-(VII) Sunspot Penumbra to Umbra Area Ratio Using the Hand-Drawing Records from Yunnan Observatories".RESEARCH IN ASTRONOMY AND ASTROPHYSICS 22.9(2022). |
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