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Related papers: Time-Dependent Modulation of Cosmic Rays in the He…

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When traveling in the heliosphere, Galactic cosmic rays (GCRs) are subjected to the solar modulation effect, a quasiperiodical change of their intensity caused by the 11-year cycle of solar activity. Here we investigate the association of…

Solar and Stellar Astrophysics · Physics 2022-11-22 Nicola Tomassetti , Bruna Bertucci , Emanuele Fiandrini

The recovery of cosmic ray protons of energy ~150-250 MeV/nuc in solar cycle #23 from 2004 to 2010 has been followed at the Earth using IMP, ACE and balloon data and also at V2 between 74-92 AU and at V1 beyond the heliospheric termination…

Geophysics · Physics 2011-11-11 W. R. Webber , F. B. McDonald , P. R. Higbie , B. Heikkila

When entering the heliosphere, Galactic cosmic rays (GCRs) are influenced by magnetic turbulence and Solar wind disturbances, which cause the so-called "solar modulation" effect. Understanding the time-dependent relationship between the…

High Energy Astrophysical Phenomena · Physics 2019-08-06 Bruna Bertucci , Emanuele Fiandrini , Behrouz Khiali , Nicola Tomassetti

The intensity and energy spectrum of galactic cosmic rays in the heliosphere are significantly influenced by the 11-year solar cycle, a phenomenon known as solar modulation. Understanding this effect and its underlying physical mechanisms…

Instrumentation and Methods for Astrophysics · Physics 2025-08-26 David Pelosi , Fernando Barão , Bruna Bertucci , Francesco Faldi , Emanuele Fiandrini , Alejandro Reina Conde , Miguel Orcinha , Nicola Tomassetti

We have determined the solar modulation potential, phi, vs. time that is observed at Voyager 1 and 2 from measurements of the H and He nuclei intensities at a common energy of 250 MeVnuc. The H nuclei have a rigidity 0.7 GV, the He nuclei…

Space Physics · Physics 2017-06-12 W. R. Webber , E. C. Stone , A. C. Cummings , B. Heikkila , N. Lal

The last solar minimum activity period, and the consequent minimum modulation conditions for cosmic rays, was unusual. The highest levels of galactic protons were recorded at Earth in late 2009 in contrast to expectations. Proton spectra…

Solar and Stellar Astrophysics · Physics 2015-06-12 M. S. Potgieter , E. E. Vos , M. Boezio , N. De Simone , V. Di Felice , V. Formato

Voyager 1 has explored the solar wind-interstellar medium interaction region between the terminal shock and heliopause following the intensity distribution of galactic cosmic ray protons above 200 MeV energy. Before this component reached…

Solar and Stellar Astrophysics · Physics 2015-09-09 J. J. Quenby , W. R. Webber

We investigate the solar modulation effect with the long time cosmic ray proton and helium spectrum measured by AMS-02 on the time scale of a Bartels rotation (27 days) between May 2011 and May 2017. The time-span covers the negative…

High Energy Astrophysical Phenomena · Physics 2020-11-26 Bing-Bing Wang , Xiao-Jun Bi , Kun Fang , Sujie Lin , Peng-Fei Yin

Cosmic ray intensities (CRIs) recorded by sixteen neutron monitors have been used to study its dependence on the tilt angles (TA) of the heliospheric current sheet (HCS) during period 1976-2014, which covers three solar activity cycles 21,…

Space Physics · Physics 2017-08-21 M. A. El-Borie , S. A. Gwaily , A. A. Bishara

Global gradients for cosmic-ray (CR) protons in the heliosphere are computed with a comprehensive modulation model for the recent prolonged solar minimum of Cycle 23/24. Fortunately, the PAMELA (Payload for Antimatter Matter Exploration and…

Space Physics · Physics 2016-08-17 E. E. Vos , M. S. Potgieter

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the CALorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the…

We have obtained the energy spectra of cosmic ray He, B, C, O, Mg, S and Fe nuclei in the range 0.5-1.5 GeV/nuc and above using the penetrating particle mode of the High Energy Telescope, part of the Cosmic Ray Science (CRS) experiment on…

Space Physics · Physics 2017-12-11 W. R. Webber , N. Lal , E. C. Stone , A. C. Cummings , B. Heikkila

We employ a data-driven approach to investigate the rigidity and spatial dependence of the diffusion of cosmic rays in the turbulent magnetic field of the Milky Way. Our analysis combines data sets from the experiments Voyager, AMS-02,…

High Energy Astrophysical Phenomena · Physics 2024-04-24 Mattia Di Mauro , Michael Korsmeier , Alessandro Cuoco

Since crossing the heliopause on August 25, 2012, Voyager 1 observed reductions in galactic cosmic ray count rates caused by a time-varying depletion of particles with pitch angles near 90-deg, while intensities of particles with other…

Space Physics · Physics 2019-05-30 J. S. Rankin , E. C. Stone , A. C. Cummings , D. J. McComas , N. Lal , B. C. Heikkila

Very high intensities of galactic cosmic rays measured by Voyager 1 in the heliosheath appear to be incompatible with the presence of a modulation "wall" near the heliopause produced by a pile up of the heliospheric magnetic field. We…

Space Physics · Physics 2013-02-14 V. Florinski , F. Alouani-Bibi , J. Kota , X. Guo

On their way through the heliosphere, Galactic Cosmic Rays (GCRs) are modulated by various effects before they can be detected at Earth. This process can be described by the Parker equation, which calculates the phase space distribution of…

Space Physics · Physics 2017-11-28 Jan Gieseler , Bernd Heber , Konstantin Herbst

The spectra of galactic cosmic rays (GCRs) contain crucial information about their origin and propagation through the interstellar medium. When GCRs reach Earth, they are significantly influenced by the solar wind and the heliospheric…

High Energy Astrophysical Phenomena · Physics 2025-04-23 Cheng-Rui Zhu , Kai-Kai Duan

Galactic cosmic rays (GCRs) are affected by solar modulation while they propagate through the heliosphere. The study of the time variation of GCR spectra observed at Earth can shed light on the underlying physical processes, specifically…

Space Physics · Physics 2023-09-18 Claudio Corti , Peter Sadowski , Nikolay Nikonov , Marius Potgieter , Veronica Bindi

A key goal of heliophysics is to understand how cosmic rays propagate in the solar system's complex, dynamic environment. One observable is solar modulation, i.e., how the flux and spectrum of cosmic rays changes as they propagate inward.…

Solar and Stellar Astrophysics · Physics 2022-09-22 Jung-Tsung Li , John F. Beacom , Annika H. G. Peter

During the solar journey through galactic space, variations in the physical properties of the surrounding interstellar medium (ISM) modify the heliosphere and modulate the flux of galactic cosmic rays (GCR) at the surface of the Earth, with…

Astrophysics of Galaxies · Physics 2015-05-20 Priscilla C. Frisch , Hans-Reinhard Mueller