Publication
Evidence for a Time Lag in Solar Modulation of Galactic Cosmic Rays
| dc.contributor.author | Tomassetti, Nicola | |
| dc.contributor.author | Orcinha, Miguel | |
| dc.contributor.author | Barão, Fernando | |
| dc.contributor.author | Bertucci, Bruna | |
| dc.date.accessioned | 2019-02-04T13:33:03Z | |
| dc.date.available | 2019-02-04T13:33:03Z | |
| dc.date.issued | 2017-11-08 | |
| dc.date.updated | 2019-02-04T13:33:03Z | |
| dc.description.abstract | The solar modulation effect of cosmic rays in the heliosphere is an energy-, time-, and particle-dependent phenomenon that arises from a combination of basic particle transport processes such as diffusion, convection, adiabatic cooling, and drift motion. Making use of a large collection of time-resolved cosmic-ray data from recent space missions, we construct a simple predictive model of solar modulation that depends on direct solar-physics inputs: the number of solar sunspots and the tilt angle of the heliospheric current sheet. Under this framework, we present calculations of cosmic-ray proton spectra, positron/electron and antiproton/proton ratios, and their time dependence in connection with the evolving solar activity. We report evidence for a time lag ${\rm{\Delta }}T=8.1\pm \,1.2$ months, between solar-activity data and cosmic-ray flux measurements in space, which reflects the dynamics of the formation of the modulation region. This result enables us to forecast the cosmic-ray flux near Earth well in advance by monitoring solar activity. | |
| dc.description.version | Peer Reviewed | |
| dc.identifier | Astrophys.J. 849 (2017) L32 Astrophysical Journal Letters 849 (2017) L32; DOI 10.3847/2041-8213/aa9373 | |
| dc.identifier.uri | http://dx.doi.org/10.3847/2041-8213/aa9373 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/27399 | |
| dc.language.iso | eng | |
| dc.title | Evidence for a Time Lag in Solar Modulation of Galactic Cosmic Rays | |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt |
| rcaap.type | article |