We analyzed satellite 5-min data on alpha-particle fluxes in energy intervals 60-160 MeV, 160-260 MeV and 330-500 MeV during January 1986 – May 2000. In the first we excluded periods with great CR increases caused by particle acceleration in solar flare events. Then we determined monthly averaged fluxes as well as 5 months and 11 months smooth averaged data. We corrected these data on drift effects according to the procedure described in Dorman (2004) in dependence of alpha-particle energies. Corrected on drifts alpha-particles fluxes we compare with expected according to convection-diffusion modulation for different values of supposed dimension of the modulation region (measured by time of solar wind propagation from the Sun to the boundary of this region Xo from 1 to 60 av. months; described in Dorman, 2004). By this way we can determine Xomax, at what the correlation coefficient reaches the maximum value. Then it can be determined the dimension of modulation region (with taking into account the influence of nonlinear processes on the solar wind speed in the outer Heliosphere according to Le Roux and Fichtner, 1997), the radial diffusion coefficient and transport path as well as expected alpha-particle intensity out of the modulation region and absolute alpha-particle modulation (relative to the alpha-particle intensity level in the interstellar space).

Dorman, L.I., Iucci, N., Parisi, M., Villoresi, G. (2004). CR-SA hysteresis phenomenon on the basis of alpha-particle satellite data.

CR-SA hysteresis phenomenon on the basis of alpha-particle satellite data

IUCCI, Nunzio;PARISI, Mario;
2004-01-01

Abstract

We analyzed satellite 5-min data on alpha-particle fluxes in energy intervals 60-160 MeV, 160-260 MeV and 330-500 MeV during January 1986 – May 2000. In the first we excluded periods with great CR increases caused by particle acceleration in solar flare events. Then we determined monthly averaged fluxes as well as 5 months and 11 months smooth averaged data. We corrected these data on drift effects according to the procedure described in Dorman (2004) in dependence of alpha-particle energies. Corrected on drifts alpha-particles fluxes we compare with expected according to convection-diffusion modulation for different values of supposed dimension of the modulation region (measured by time of solar wind propagation from the Sun to the boundary of this region Xo from 1 to 60 av. months; described in Dorman, 2004). By this way we can determine Xomax, at what the correlation coefficient reaches the maximum value. Then it can be determined the dimension of modulation region (with taking into account the influence of nonlinear processes on the solar wind speed in the outer Heliosphere according to Le Roux and Fichtner, 1997), the radial diffusion coefficient and transport path as well as expected alpha-particle intensity out of the modulation region and absolute alpha-particle modulation (relative to the alpha-particle intensity level in the interstellar space).
Dorman, L.I., Iucci, N., Parisi, M., Villoresi, G. (2004). CR-SA hysteresis phenomenon on the basis of alpha-particle satellite data.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/273266
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