Global Heliospheric Parameters and Cosmic-Ray Modulation: An Empirical Relation for the Last Decades
| Autor: | K. Alanko-Huotari, G. A. Kovaltsov, Ilya Usoskin, Kalevi Mursula |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Physics
Neutron monitor Polarity (physics) Astrophysics::High Energy Astrophysical Phenomena Empirical modelling Astronomy and Astrophysics Cosmic ray Astrophysics Magnetic flux Magnetic field Computational physics Space and Planetary Science Physics::Space Physics Modulation (music) Heliospheric current sheet |
| Zdroj: | Solar Physics. 238:391-404 |
| ISSN: | 1573-093X 0038-0938 |
| DOI: | 10.1007/s11207-006-0233-z |
| Popis: | We study empirical relations between the modulation of galactic cosmic rays quantified in terms of the modulation potential and the following global heliospheric parameters: the open solar magnetic flux, the tilt angle of the heliospheric current sheet, and the polarity of the heliospheric magnetic field. We show that a combination of these parameters explains the majority of the modulation potential variations during the neutron monitor era 1951 – 2005. Two empirical models are discussed: a quasi-linear model and a model assuming a power-law relation between the modulation potential and the magnetic flux. Both models describe the data fairly well. These empirical models provide a simple tool for evaluating various cosmic-ray related effects on different time scales. The models can be extended backwards in time or used for predictions, if the corresponding global heliospheric variables can be independently estimated. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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