activity
20182026
most citedComparison of geomagnetic indices during even and odd solar cycles SC17-SC24: Signatures of Gnevyshev gap in geomagnetic activity

18 citations · 57 across the 17 of their papers we have counts for

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12 papers · 1 filter

astro-ph.SR2026

Large-Scale Latitude-time Relationships Between the Green-Line Corona and Sunspot Activity During Solar Cycles 18-24

Jouni J. Takalo

We investigate the latitude-time relationship between the solar green-line corona and sunspot activity during Solar Cycles 18-24 using homogeneous coronal observations and a Gaussi…

astro-ph.SR2024

The latitudinal migration of the sunspot groups

Jouni J. Takalo

We analyse the monthly sunspot group (SG) data for Solar Cycles C8-C23 and calculate the average latitude of the drift path for the northern and southern hemisphere of the Sun. We…

astro-ph.SR2024★ 1 cited

The Instantaneous Response of Geomagnetic Field, near-Earth IMF and Cosmic-Ray Intensity to Solar Flares

Jouni J. Takalo

We show using superposed epoch analysis (SEA) that the most energetic protons (greater than 60 MeV) in near-Earth IMF have a peak almost immediately (less than a day) after peak in…

astro-ph.SR2023★ 4 cited

Analysis of the Solar Flare Index for Solar Cycles 18-24: Extremely Deep Gnevyshev Gap in the Chromosphere

Jouni J. Takalo

We study the solar flare index (SFI) for the solar cycles 18\,--\,24. We find that SFI has deeper Gnevyshev gap (GG) in its first principal component than other atmospheric paramet…

astro-ph.SR2022★ 5 cited

Spatial and Temporal Distribution of Solar Green Line Corona for Solar Cycles 18-24

Jouni J. Takalo

Homogeneous coronal data set (HCDS) of the green corona (Fe XIV) and coronal index of the solar activity (CI) have been used to study time-latitudinal distribution in solar cycles…

astro-ph.SR2022

Extracting Hale Cycle Related Components from Cosmic-Ray Data Using Principal Component Analysis

Jouni J. Takalo

We decompose the monthly cosmic-ray data, using several neutron monitor count rates, of Cycles 19-24 with principal component analysis (PCA). We show using different cycle limits t…