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Unusual activity of the Sun during recent decades compared to the previous 11,000 years
TLDR
A reconstruction of the sunspot number covering the past 11,400 years is reported, based on dendrochronologically dated radiocarbon concentrations, and it is pointed out that solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades.
The AD775 cosmic event revisited: the Sun is to blame
Aims. Miyake et al. (2012, Nature, 486, 240, henceforth M12) recently reported, based on 14 C data, an extreme cosmic event in about AD775. Using a simple model, M12 claimed that the event was too
Grand minima and maxima of solar activity: new observational constraints
Aims. Using a reconstruction of sunspot numbers stretching over multiple millennia, we analyze the statistics of the occurrence of grand minima and maxima and set new observational constraints on
Active longitudes in sunspot activity: Century scale persistence
A novel analysis of sunspot group data for the past 120 years reveals that sunspots in both northern and southern hemispheres are formed preferably in two persistent active longitudes separated by
Heliospheric modulation of cosmic rays: Monthly reconstruction for 1951–2004
[1] The differential energy spectrum of galactic cosmic rays in the vicinity of the Earth can be parameterized by the so-called force field model which has only one parameter, the modulation
Properties of Ground Level Enhancement Events and the Associated Solar Eruptions During Solar Cycle 23
Solar cycle 23 witnessed the most complete set of observations of coronal mass ejections (CMEs) associated with the Ground Level Enhancement (GLE) events. We present an overview of the observed
Solar modulation parameter for cosmic rays since 1936 reconstructed from ground-based neutron monitors and ionization chambers
[1] The differential energy spectrum of galactic cosmic rays near Earth is often parameterized by the force field model with the only time-dependent parameter, the modulation potential ϕ. Here we
Evolution of the solar irradiance during the Holocene
Context. Long-term records of solar radiative output are vital for understanding solar variability and past climate change. Measurements of solar irradiance are available for only the last three
THE FIRST GROUND LEVEL ENHANCEMENT EVENT OF SOLAR CYCLE 24: DIRECT OBSERVATION OF SHOCK FORMATION AND PARTICLE RELEASE HEIGHTS
We report on the 2012 May 17 ground level enhancement (GLE) event, which is the first of its kind in solar cycle 24. This is the first GLE event to be fully observed close to the surface by the Solar
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