Hemispheric sunspot numbers and from 1945–2004: catalogue and NS asymmetry analysis for solar cycles 18–23

M Temmer, J Rybák, P Bendík, A Veronig… - Astronomy & …, 2006 - aanda.org
From sunspot drawings provided by the Kanzelhöhe Solar Observatory, Austria, and the
Skalnaté Pleso Observatory, Slovak Republic, we extracted a data catalogue of hemispheric …

Evolutionary Relationship between Sunspot Groups and Soft X-Ray Flares over Solar Cycles 21–25

J Lin, F Wang, L Deng, H Deng, Y Mei… - The Astrophysical …, 2023 - iopscience.iop.org
Studying the interaction between solar flares and sunspot groups (SGs) is crucial for
understanding and predicting solar activity. We examined the distribution, correlation, and …

Evolutionary aspects and north-south asymmetry of soft X-ray flare index during solar cycles 21, 22, and 23

B Joshi, R Bhattacharyya, KK Pandey… - Astronomy & …, 2015 - aanda.org
Aims. In this paper, we investigate the temporal evolution and north–south (N–S) asymmetry
in the occurrence of solar flares during cycle 21, 22, and 23, and compare the results with …

Regularity of the North–South asymmetry of solar activity: revisited

J Zhang, W Feng - The Astronomical Journal, 2015 - iopscience.iop.org
Extended time series of Solar Activity Indices (ESAI) extended the Greenwich series of
sunspot area from the year 1874 back to 1821. The ESAI's yearly sunspot area in the …

Statistical analysis of filament features based on the Hα solar images from 1988 to 2013 by computer automated detection method

Q Hao, C Fang, W Cao, PF Chen - The Astrophysical Journal …, 2015 - iopscience.iop.org
We improve our filament automated detection method which was proposed in our previous
works. It is then applied to process the full disk Hα data mainly obtained by the Big Bear …

The hemispheric variation of the flare index during solar cycles 20–23

LH Deng, ZQ Qu, T Liu, KR Wang - Astronomische Nachrichten, 2013 - Wiley Online Library
In this paper, the monthly counts of flare index in the northern and southern hemispheres are
used to investigate the hemispheric variation of the flare index in each of solar cycles 20–23 …

North and South hemispheric solar activity for cycles 21–23: asymmetry and conditional volatility of plage region areas

E Gonçalves, N Mendes-Lopes, I Dorotovič… - Solar Physics, 2014 - Springer
We study the dynamic evolution of the time series describing the plage regions areas
observed daily at the Observatório Astronómico da Universidade de Coimbra, in each one of …

North–South asymmetry of solar activity on a long timescale

YA Nagovitsyn, AI Kuleshova - Geomagnetism and Aeronomy, 2015 - Springer
Based on the formulated hypothesis and the catalogs of low-latitude auroras, the time
variations in the north–south (N–S) asymmetry of solar activity (SA) have been reconstructed …

The hemispheric asymmetry of polar faculae

LH Deng, ZQ Qu, XL Yan, T Liu, KR Wang - Journal of Astrophysics and …, 2012 - Springer
In this paper, the north–south (N–S) asymmetry of the polar faculae at relatively low (RLLs),
relatively high (RHLs) as well as total latitudes (TLs) respectively, are investigated. It is found …

[PDF][PDF] The long-term hemispheric variation of polar faculae

LH Deng, ZQ Qu, T Liu, WJ Huang - Journal of the Korean …, 2011 - researchgate.net
In this paper, the long-term hemispheric variation of the polar faculae is investigated. It is
found that,(1) both the NS asymmetry and NS asynchrony of the polar faculae exhibit a long …