3 papers
astro-ph.SR2026
Amplification of active region equatorial dipole
Ismo Tähtinen
The effect of active region parameters on the evolution of solar axial dipole is well understood. However, their effect on the solar equatorial dipole has not been studied in detai…
astro-ph.SR2026
Photospheric index of geomagnetic activity
Ismo Tähtinen, Timo Qvick, Timo Asikainen +1
Geomagnetic indices quantify the disturbances of the Earth's magnetic field. They form an important space weather and space climate record that tracks solar-terrestrial effects on…
astro-ph.SR2024
Transition to a weaker Sun: Changes in the solar atmosphere during the decay of the Modern Maximum
K. Mursula, A. A. Pevtsov, T. Asikainen +2
The Sun experienced a period of unprecedented activity during the 20th century, now called the Modern Maximum (MM). The decay of the MM after cycle 19 has changed the Sun, the heli…