Relation of decline characteristics of 2-4.6 MeV protons in SEP events to solar wind parameters

E. I. Daibog, S. Kahler, K. Kecskeméty, Yu I. Logachev

Research output: Contribution to journalArticle

Abstract

The shape of the particle flux decline in solar energetic particle (SEP) events is of particular importance in understanding the propagation of energetic particles in the interplanetary medium. Power-law time profiles indicate the dominance of diffusive propagation, whereas exponential-law decline emphasizes convection transport and adiabatic deceleration. Values obtained theoretically for the decay time in the latter case are reasonably close to the fitted slopes in nearly half of all events when the solar wind speed stays nearly constant. Dependencies of characteristic decay time τ and spectral index γ on environmental plasma parameters are considered. Parts of exponential-law declines when solar wind speed: (a) decreases with time, (b) is constant, and (c) increases with time through the interval are analyzed separately. Both average values and dispersions of size distributions of τ for these three groups markedly differ in accordance with theoretical expectations.

Original languageEnglish
Pages (from-to)1882-1886
Number of pages5
JournalAdvances in Space Research
Volume35
Issue number10
DOIs
Publication statusPublished - 2005

Fingerprint

Solar wind
energetic particles
solar wind
Protons
energetics
protons
Deceleration
Dispersions
Fluxes
Plasmas
wind velocity
interplanetary medium
propagation
decay
deceleration
guy wires
flux (rate)
power law
convection
particle

Keywords

  • Charged particle propagation
  • Solar energetic particles

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Relation of decline characteristics of 2-4.6 MeV protons in SEP events to solar wind parameters. / Daibog, E. I.; Kahler, S.; Kecskeméty, K.; Logachev, Yu I.

In: Advances in Space Research, Vol. 35, No. 10, 2005, p. 1882-1886.

Research output: Contribution to journalArticle

Daibog, E. I. ; Kahler, S. ; Kecskeméty, K. ; Logachev, Yu I. / Relation of decline characteristics of 2-4.6 MeV protons in SEP events to solar wind parameters. In: Advances in Space Research. 2005 ; Vol. 35, No. 10. pp. 1882-1886.
@article{ff997f1a41e8484a9844230a36dd7a61,
title = "Relation of decline characteristics of 2-4.6 MeV protons in SEP events to solar wind parameters",
abstract = "The shape of the particle flux decline in solar energetic particle (SEP) events is of particular importance in understanding the propagation of energetic particles in the interplanetary medium. Power-law time profiles indicate the dominance of diffusive propagation, whereas exponential-law decline emphasizes convection transport and adiabatic deceleration. Values obtained theoretically for the decay time in the latter case are reasonably close to the fitted slopes in nearly half of all events when the solar wind speed stays nearly constant. Dependencies of characteristic decay time τ and spectral index γ on environmental plasma parameters are considered. Parts of exponential-law declines when solar wind speed: (a) decreases with time, (b) is constant, and (c) increases with time through the interval are analyzed separately. Both average values and dispersions of size distributions of τ for these three groups markedly differ in accordance with theoretical expectations.",
keywords = "Charged particle propagation, Solar energetic particles",
author = "Daibog, {E. I.} and S. Kahler and K. Kecskem{\'e}ty and Logachev, {Yu I.}",
year = "2005",
doi = "10.1016/j.asr.2005.01.004",
language = "English",
volume = "35",
pages = "1882--1886",
journal = "Advances in Space Research",
issn = "0273-1177",
publisher = "Elsevier Limited",
number = "10",

}

TY - JOUR

T1 - Relation of decline characteristics of 2-4.6 MeV protons in SEP events to solar wind parameters

AU - Daibog, E. I.

AU - Kahler, S.

AU - Kecskeméty, K.

AU - Logachev, Yu I.

PY - 2005

Y1 - 2005

N2 - The shape of the particle flux decline in solar energetic particle (SEP) events is of particular importance in understanding the propagation of energetic particles in the interplanetary medium. Power-law time profiles indicate the dominance of diffusive propagation, whereas exponential-law decline emphasizes convection transport and adiabatic deceleration. Values obtained theoretically for the decay time in the latter case are reasonably close to the fitted slopes in nearly half of all events when the solar wind speed stays nearly constant. Dependencies of characteristic decay time τ and spectral index γ on environmental plasma parameters are considered. Parts of exponential-law declines when solar wind speed: (a) decreases with time, (b) is constant, and (c) increases with time through the interval are analyzed separately. Both average values and dispersions of size distributions of τ for these three groups markedly differ in accordance with theoretical expectations.

AB - The shape of the particle flux decline in solar energetic particle (SEP) events is of particular importance in understanding the propagation of energetic particles in the interplanetary medium. Power-law time profiles indicate the dominance of diffusive propagation, whereas exponential-law decline emphasizes convection transport and adiabatic deceleration. Values obtained theoretically for the decay time in the latter case are reasonably close to the fitted slopes in nearly half of all events when the solar wind speed stays nearly constant. Dependencies of characteristic decay time τ and spectral index γ on environmental plasma parameters are considered. Parts of exponential-law declines when solar wind speed: (a) decreases with time, (b) is constant, and (c) increases with time through the interval are analyzed separately. Both average values and dispersions of size distributions of τ for these three groups markedly differ in accordance with theoretical expectations.

KW - Charged particle propagation

KW - Solar energetic particles

UR - http://www.scopus.com/inward/record.url?scp=24944431732&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=24944431732&partnerID=8YFLogxK

U2 - 10.1016/j.asr.2005.01.004

DO - 10.1016/j.asr.2005.01.004

M3 - Article

AN - SCOPUS:24944431732

VL - 35

SP - 1882

EP - 1886

JO - Advances in Space Research

JF - Advances in Space Research

SN - 0273-1177

IS - 10

ER -