{
  "id": "1707.06916",
  "version": "v1",
  "published": "2017-07-21T14:27:25.000Z",
  "updated": "2017-07-21T14:27:25.000Z",
  "title": "A time-lag in solar modulation of galactic cosmic rays determined from time-resolved data collected in space",
  "authors": [
    "Nicola Tomassetti",
    "Miguel Orcinha",
    "Fernando Barao",
    "Bruna Bertucci"
  ],
  "comment": "5 pages, 5 figures",
  "categories": [
    "astro-ph.HE",
    "astro-ph.EP",
    "astro-ph.SR",
    "physics.space-ph"
  ],
  "abstract": "The solar modulation effect of cosmic rays in the heliosphere is an energy-, time-, and particle-dependent phenomenon which 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 which 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 $\\Delta$T\\,=\\,8.1\\,$\\pm$\\,0.9 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",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-07-21T14:27:25.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galactic cosmic rays",
      "time-resolved data",
      "cosmic-ray flux",
      "basic particle transport processes",
      "solar modulation effect"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}