Time variations of low-energy protons and helium nuclei (0.3-10 MeV/nucleon) during the quiescent time of solar activity in the inner heliosphere

M. A. Zeldovich, Yu I. Logachev, G. M. Surova, K. Kecskeméty

Research output: Contribution to journalArticle

Abstract

Time variations with a duration of -0.6-1.5 years are studied in the interplanetary space for protons and helium nuclei with energies of 0.3-10 MeV per nucleon at a quiescent time of solar activity. It is shown that at 1 AU in the periods 1978-1981 and 1988-1990, at the phases of growth of the 21 st and 22nd solar cycles, the background fluxes of these particles determined as minimum intensity levels in every month increased demonstrating steplike variations. At the same time, the intensity of galactic cosmic rays (GCRs) decreased also with the formation of modulation steps. Each step of low-energy particles was finished by a deep minimum of intensity ("gap") in both protons and helium nuclei and with a simultaneous short-term increase of the GCR intensity. We present the results of studying five such steps in the intensity of low-energy particles that were observed simultaneously and were opposite in phase with modulation steps of galactic particles. The lowest values of the H/He ratio were recorded at the end of every step, at the lowest intensities of these particles, i.e., in the "gap." The true background population at 1 AU was detected precisely at these time intervals, when the contributions of flare particles and those accelerated in the international space were minimum. Various possibilities of the origination of the steplike variations of the background fluxes of protons and helium nuclei with energies of 0.3-10 MeV per nucleon, correlated with similar GCR variations, are discussed.

Original languageEnglish
Pages (from-to)235-244
Number of pages10
JournalCosmic Research
Volume41
Issue number3
DOIs
Publication statusPublished - May 2003

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Cosmic rays
heliosphere
proton energy
solar activity
helium
Helium
Protons
nuclei
Modulation
cosmic ray
Fluxes
energy
particle energy
protons
modulation
interplanetary space
solar cycles
solar cycle
flares
particle

ASJC Scopus subject areas

  • Aerospace Engineering
  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Time variations of low-energy protons and helium nuclei (0.3-10 MeV/nucleon) during the quiescent time of solar activity in the inner heliosphere. / Zeldovich, M. A.; Logachev, Yu I.; Surova, G. M.; Kecskeméty, K.

In: Cosmic Research, Vol. 41, No. 3, 05.2003, p. 235-244.

Research output: Contribution to journalArticle

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