MODULATION OF LONG-TERM COSMIC RAY VARIATIONS DURING SOLAR ACTIVITY MINIMUM OF THE 24TH SOLAR CYCLE

Discussion timeslot (ZOOM-Meeting): 16. July 2021 - 18:00
ZOOM-Meeting URL: https://icrc2021.desy.de/pf_access_abstracts
Corresponding Session: https://icrc2021-venue.desy.de/channel/Presenter-Forum-1-Evening-All-Categories/48
Abstract:
'*The observed weakening of the global magnetic field of the Sun, which began at the end of the 22nd cycle of solar activity (SA) raise the question of the response of this phenomenon in cosmic rays (CR) propagating in the heliosphere. Weak long-term modulation in the 23rd and 24th cycles of SA is the result of the trend of the solar field in cycles with different signs of the total magnetic field of the Sun (qa±1) for particles in the rigidity range we studied (1-25GV). The work was carried out on the material of continuous CR observations (1957-2020) by a network of neutron monitors, telescopes, and stratospheric balloon probes. The spectrum of CR variations in the minimum of 24/25 (2019-2020) was determined using the global spectrographic method developed by us. The spectral characteristics of the variations of the anomalous 24th SA cycle are compared (base 1.1987-12.1987) with the corresponding characteristics of the previous SA cycles (19-23). At SA minimum of 24/25 a flat (confirming the drift modulation theory for qA+1) maximum of the CR flow is observed from 2018 to the present time. At the same time, the amplitude of variations for low-energy particles (observed in the stratosphere) exceeds the value of the base period variations by ~8% and is 0.8% of the amplitude of the CR variations at the minimum of 23/24 in 2009. Max particle flow medium and high energies observed in neutron monitors and telescopes 1-2% lower than that of 23/24. If distribution of achieving minimum 23/24 particles of different energies indicated the beginning of a new cycle in CR.'

Authors: Lev Dorman | Lev Pustilnik
Indico-ID: 1424
Proceeding URL: https://pos.sissa.it/395/1314