Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity
There was a research on the prolongation of solar cycle 23 by the solar cyclic variation of solar, interplanetary geomagnetic parameters by Oh & Kim (2013). They also suggested that the sunspot number cannot typically explain the variation of total solar irradiance any more. Instead of the sun...
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| Format: | Article |
| Language: | English |
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The Korean Space Science Society
2014-06-01
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| Series: | Journal of Astronomy and Space Sciences |
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| Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2014/v31n2/OJOOBS_2014_v31n2_145.pdf |
| _version_ | 1797368481740488704 |
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| author | Suyeon Oh |
| author_facet | Suyeon Oh |
| author_sort | Suyeon Oh |
| collection | DOAJ |
| description | There was a research on the prolongation of solar cycle 23 by the solar cyclic variation of solar, interplanetary geomagnetic
parameters by Oh & Kim (2013). They also suggested that the sunspot number cannot typically explain the variation of total
solar irradiance any more. Instead of the sunspot number, a new index is introduced to explain the degree of solar activity.
We have analyzed the frequency of sunspot appearance, the length of solar cycle, and the rise time to a solar maximum
as the characteristics of solar cycle. Then, we have examined the predictability of solar activity by the characteristics of
preceding solar cycle. We have also investigated the hemispheric variation of flare index for the periods that the leading
sunspot has the same magnetic polarity. As a result, it was found that there was a good correlation between the length of
preceding solar cycle and spotless days. When the length of preceding solar cycle gets longer, the spotless days increase.
It is also shown that the shorter rise time to a solar maximum is highly correlated with the increase of sunspots at a solar
maximum. Therefore, the appearance frequency of spotless days and the length of solar cycle are more significant than
the general sunspot number as an index of declining solar activity. Additionally, the activity of flares leads in the northern
hemisphere and is stronger in the hemisphere with leading sunspots in positive polarity than in the hemisphere with
leading sunspots in negative polarity. This result suggests that it is necessary to analyze the magnetic polarity’s effect on the
flares and to interpret the period from the solar maximum to solar maximum as the definition of solar cycle. |
| first_indexed | 2024-03-08T17:33:07Z |
| format | Article |
| id | doaj.art-d6e2aefe29f6481da99912ab73ecc449 |
| institution | Directory Open Access Journal |
| issn | 2093-5587 2093-1409 |
| language | English |
| last_indexed | 2024-03-08T17:33:07Z |
| publishDate | 2014-06-01 |
| publisher | The Korean Space Science Society |
| record_format | Article |
| series | Journal of Astronomy and Space Sciences |
| spelling | doaj.art-d6e2aefe29f6481da99912ab73ecc4492024-01-02T14:28:20ZengThe Korean Space Science SocietyJournal of Astronomy and Space Sciences2093-55872093-14092014-06-0131214514810.5140/JASS.2014.31.2.145Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle ActivitySuyeon Oh0Department of Earth Science Education, Chonnam National University, Gwangju 500-757, KoreaThere was a research on the prolongation of solar cycle 23 by the solar cyclic variation of solar, interplanetary geomagnetic parameters by Oh & Kim (2013). They also suggested that the sunspot number cannot typically explain the variation of total solar irradiance any more. Instead of the sunspot number, a new index is introduced to explain the degree of solar activity. We have analyzed the frequency of sunspot appearance, the length of solar cycle, and the rise time to a solar maximum as the characteristics of solar cycle. Then, we have examined the predictability of solar activity by the characteristics of preceding solar cycle. We have also investigated the hemispheric variation of flare index for the periods that the leading sunspot has the same magnetic polarity. As a result, it was found that there was a good correlation between the length of preceding solar cycle and spotless days. When the length of preceding solar cycle gets longer, the spotless days increase. It is also shown that the shorter rise time to a solar maximum is highly correlated with the increase of sunspots at a solar maximum. Therefore, the appearance frequency of spotless days and the length of solar cycle are more significant than the general sunspot number as an index of declining solar activity. Additionally, the activity of flares leads in the northern hemisphere and is stronger in the hemisphere with leading sunspots in positive polarity than in the hemisphere with leading sunspots in negative polarity. This result suggests that it is necessary to analyze the magnetic polarity’s effect on the flares and to interpret the period from the solar maximum to solar maximum as the definition of solar cycle.http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2014/v31n2/OJOOBS_2014_v31n2_145.pdfsolar cyclic variationsolar activityspotless day23/24 solar cycle minimumflare index |
| spellingShingle | Suyeon Oh Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity Journal of Astronomy and Space Sciences solar cyclic variation solar activity spotless day 23/24 solar cycle minimum flare index |
| title | Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity |
| title_full | Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity |
| title_fullStr | Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity |
| title_full_unstemmed | Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity |
| title_short | Frequency of Solar Spotless Days and Flare Index as Indices of Solar Cycle Activity |
| title_sort | frequency of solar spotless days and flare index as indices of solar cycle activity |
| topic | solar cyclic variation solar activity spotless day 23/24 solar cycle minimum flare index |
| url | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2014/v31n2/OJOOBS_2014_v31n2_145.pdf |
| work_keys_str_mv | AT suyeonoh frequencyofsolarspotlessdaysandflareindexasindicesofsolarcycleactivity |