The rigidity dependence of Forbush decreases observed at the Earth

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA00089· OSTI ID:5262546

Lockwood, J A; Webber, W R ^[1]; Debrunner, H ^[2]

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1. Univ. of New Hampshire, Durham (USA)
2. Univ. of Bern (Switzerland)

The rigidity dependence of the large Forbush decreases occurring on July 23, 1981, July 11, 1982, and February 6, 1986, has been determined using neutron monitor and IMP spacecraft data which cover the energy range from about 50 MeV to 30 GeV. The contribution of solar flare protons to the lower-energy data from the IMP cosmic ray telescopes was carefully removed. The authors found that the rigidity dependences of the magnitudes of the July 1981, July 1982, and February 1986 Forbush decreases for P {ge} 2 GV were given by exp ({minus}1/P{sup 0.75}), exp ({minus}1/P{sup 0.6}), and exp ({minus}1/P{sup 1.0}), respectively. For 0.5 {le} P {le} 2 GV the magnitude of the Forbush decreases in July 1981 and July 1982 was rigidity independent. The February 1986 event also appeared to be rigidity independent below {approximately}1 GV. The characteristic recovery time of these Forbush decreases was found to be not strongly rigidity dependent. These results on the rigidity dependence of Forbush decreases for 0.5 < P < 20 GV are discussed in the context of proposed models.

• OSTI ID: 5262546
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics &amp; Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
COSMIC RADIATION
COSMIC RAY FLUX
DATA ANALYSIS
EARTH PLANET
ELEMENTARY PARTICLES
FERMIONS
FORBUSH DECREASE
HADRONS
IONIZING RADIATIONS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MODULATION
MONITORS
NEUTRON MONITORS
NUCLEONS
PLANETS
PROTONS
RADIATION FLUX
RADIATION MONITORS
RADIATIONS
SATELLITES
SOLAR PARTICLES
SOLAR PROTONS
SOLAR RADIATION
STELLAR RADIATION
TELESCOPE COUNTERS
THRESHOLD RIGIDITY