Features of cosmic rays modulation in 23-24 cycles of solar activity
Abstract
A significant trend in the magnetic field of the Sun, the beginning of which is noted during the transition from the end of the 22nd cycle, continues to be observed to the present (the end of the 24th cycle). The main characteristics of the solar magnetic field and the associated IMF are crucial for the modulation of cosmic rays (CR). In long-term CR variations in 23-24 cycles of SA, the weakening of the solar magnetic field is displayed, and a comparison of variations in this period with variations in previous cycles (21-22th) allows us to reveal new features of CR modulation (which turned out to be the weakest for the entire time of neutron monitors operation), that have not been observed until the last two decades. In our modulation model, we took into account the effect of the solar polar magnetic field (Hpol), the characteristics of the large-scale fields of the Sun (Bss), the slope of the neutral layer (hcst), the influence of the area of coronal holes (Al3), and the sporadic activity of the Sun (CME index). Model calculations of CR modulation for two time intervals (21-22 and 23-24 cycles of SA) showed: with a slight difference in the obtained regression characteristics (and the delay time of CR variations relative to the SA indices), the contributions to the created CR modulation from the above SA indices differs greatly in analyzed periods. The possible reasons for the differences between the last two CA cycles from the previous ones are discussed.
- Publication:
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43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E1384D