Solar flare activity, 1937-2024: Introducing the New Hemispheric Solar flare index (hSFI) in the context of 2024's major Solar storm events

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00642104" target="_blank" >RIV/67985815:_____/25:00642104 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0372078" target="_blank" >https://hdl.handle.net/11104/0372078</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2025SW004515" target="_blank" >10.1029/2025SW004515</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Solar flare activity, 1937-2024: Introducing the New Hemispheric Solar flare index (hSFI) in the context of 2024's major Solar storm events

Popis výsledku v původním jazyce

A new daily composite of the solar flare index (SFI) and the hemispherically-resolved versions (hSFI) are presented for 1937 to 2024. The data set confirms that the northern hemisphere (NH) dominated solar flare activity during Solar Cycles 17 to 21, but that the southern hemisphere has dominated from Solar Cycle 22 to present. That said, the highest SFI value occurred in the NH during the recent superstorm of May 2024. In sunspot activity, the Gnevyshev-Ohl rule shows that the sum of sunspot numbers during even-numbered cycles is related to those of adjacent odd-numbered cycles. A similar rule appears to apply to SFI. The Gnevyshev gap phenomenon where solar maximum activity sometimes has two peaks separated by up to 1-2 years of a gap is confirmed for SFI. Although our data set represents the longest continuous daily data set for solar flare activity to-date, it is known that stronger solar flare events occurred before 1937. Therefore, a brief discussion of earlier solar flare events in the historical record is also provided for context. The statistics of the SFI and hSFI series are compared to other solar and geomagnetic activity indices, including the May and October 2024 solar storms. Statistical analysis of past geomagnetic storms confirms they are more frequent during active cycles and less frequent during solar minima. Strong geomagnetic storms are also more likely to occur during the positive phase of a 1.7 year's quasi-biennial oscillation in solar activity. The likelihood of low-magnetic latitude aurorae seems to have a 30 year periodicity component.

Název v anglickém jazyce

Solar flare activity, 1937-2024: Introducing the New Hemispheric Solar flare index (hSFI) in the context of 2024's major Solar storm events

Popis výsledku anglicky

A new daily composite of the solar flare index (SFI) and the hemispherically-resolved versions (hSFI) are presented for 1937 to 2024. The data set confirms that the northern hemisphere (NH) dominated solar flare activity during Solar Cycles 17 to 21, but that the southern hemisphere has dominated from Solar Cycle 22 to present. That said, the highest SFI value occurred in the NH during the recent superstorm of May 2024. In sunspot activity, the Gnevyshev-Ohl rule shows that the sum of sunspot numbers during even-numbered cycles is related to those of adjacent odd-numbered cycles. A similar rule appears to apply to SFI. The Gnevyshev gap phenomenon where solar maximum activity sometimes has two peaks separated by up to 1-2 years of a gap is confirmed for SFI. Although our data set represents the longest continuous daily data set for solar flare activity to-date, it is known that stronger solar flare events occurred before 1937. Therefore, a brief discussion of earlier solar flare events in the historical record is also provided for context. The statistics of the SFI and hSFI series are compared to other solar and geomagnetic activity indices, including the May and October 2024 solar storms. Statistical analysis of past geomagnetic storms confirms they are more frequent during active cycles and less frequent during solar minima. Strong geomagnetic storms are also more likely to occur during the positive phase of a 1.7 year's quasi-biennial oscillation in solar activity. The likelihood of low-magnetic latitude aurorae seems to have a 30 year periodicity component.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Space Weather-the International Journal of Research and Applications

ISSN

1542-7390

e-ISSN

1542-7390

Svazek periodika

23

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

37

Strana od-do

e2025SW004515

Kód UT WoS článku

001613580100001

EID výsledku v databázi Scopus

2-s2.0-105022015150