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Related papers: Heliosphere Dimension and Cosmic Ray Modulation

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The time-dependent modulation of galactic cosmic rays in the heliosphere is studied by computing intensities using a time-dependent modulation model. By introducing recent theoretical advances in the transport coefficients in the model,…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Rex Manuel , Stefan Ferreira , Marius Potgieter

A two-dimensional, time-dependent numerical model is used to calculate the modulation of cosmic rays in the heliosphere. Computations are compared to spacecraft observations in the inner and outer heliosphere. It is shown that the model…

High Energy Astrophysical Phenomena · Physics 2013-10-22 Rex Manuel , Stefan Ferreira , Marius Potgieter

The cosmic rays differential intensity inside the heliosphere, for energy below 30 GeV/nuc, depends on solar activity and interplanetary magnetic field polarity. This variation, termed solar modulation, is described using a 2-D (radius and…

Solar and Stellar Astrophysics · Physics 2015-06-12 P. Bobik , G. Boella , M. J. Boschini , C. Consolandi , S. Della Torre , M. Gervasi , D. Grandi , K. Kudela , S. Pensotti , P. G. Rancoita , D. Rozza , M. Tacconi

The intensity and energy spectrum of energetic charged radiation in the heliosphere are significantly influenced by solar activity. This phenomenon is known as solar modulation of galactic cosmic rays. As interplanetary travel becomes a…

High Energy Astrophysical Phenomena · Physics 2025-09-16 Miguel Orcinha , Fernando Barão , Bruna Bertucci , Emanuele Fiandrini , David Pelosi , Nicola Tomassetti

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

The heliospheric modulation model HelMod solve the transport-equation for the Galactic Cosmic Rays propagation through the heliosphere down to Earth. It is based on a 2-D Monte Carlo approach, that includes a general description of the…

Experimental results by Milagro, HAWC, and ARGO-YBJ have observed variations in the energy spectrum of cosmic rays at TeV scales in different regions of the sky. These findings on the spectral anisotropy provide insights into cosmic ray…

High Energy Astrophysical Phenomena · Physics 2026-03-04 Vanessa López-Barquero , Andrés Marín Portuguez , Paolo Desiati , Juan Carlos Díaz-Vélez

An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and…

Solar and Stellar Astrophysics · Physics 2016-11-28 Ilias Cholis , Dan Hooper , Tim Linden

We study the time-dependent modulation effect and derive the local interstellar spectra (LIS) for the cosmic ray (CR) proton, helium, boron and carbon. A two-dimensional modulation model including the variation of the interplanetary…

High Energy Astrophysical Phenomena · Physics 2019-09-25 Bing-Bing Wang , Xiao-Jun Bi , Kung Fang , Su-Jie Lin , Peng-Fei Yin

Galactic cosmic rays (CRs) inside the heliosphere are affected by solar modulation. To investigate this phenomenon and its underlying physical mechanisms, we have performed a data-driven analysis of the temporal dependence of the CR proton…

High Energy Astrophysical Phenomena · Physics 2021-07-21 Emanuele Fiandrini , Nicola Tomassetti , Bruna Bertucci , Federico Donnini , Maura Graziani , Behrouz Khiali , Alejandro Reina Conde

We develop a numerical model to study the time-dependent modulation of galactic cosmic rays (GCRs) in the inner heliosphere. In the model a time-delayed modified Parker heliospheric magnetic field (HMF) and a new diffusion coefficient…

Space Physics · Physics 2017-09-26 Gang Qin , Zhenning Shen

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,…

High Energy Astrophysical Phenomena · Physics 2018-07-31 Nicola Tomassetti , Miguel Orcinha , Fernando Barao , Bruna Bertucci

Our basic theoretical understanding of the sources of cosmic rays and their propagation through the interstellar medium is hindered by the Sun, that through the solar wind affects the observed cosmic-ray spectra. This effect is known as…

Solar and Stellar Astrophysics · Physics 2022-10-12 Ilias Cholis , Ian McKinnon

The solar modulation effect of Galactic cosmic rays is a time-dependent phenomenon that is caused by the transport of these particles through the magnetized plasma of the heliosphere. Using a data-driven model of cosmic-ray transport in the…

High Energy Astrophysical Phenomena · Physics 2019-05-22 Miguel Orcinha , Nicola Tomassetti , Fernando Barão , Bruna Bertucci

Cosmic rays (CRs) are tracers of solar events when they are associated with solar flares, but also galactic events when they come from outside our solar system. SEPs are correlated with the 11-year solar cycle while GCRs are anti-correlated…

Solar and Stellar Astrophysics · Physics 2020-10-06 Barbara Perri , Allan Sacha Brun , Antoine Strugarek , Victor Réville

The heliospheric modulation model \helmod{} is a two dimensional treatment dealing with the helio-colatitude and radial distance from Sun and is employed to solve the transport-equation for the GCR propagation through the heliosphere down…

Solar and Stellar Astrophysics · Physics 2018-10-31 M. J. Boschini , S. Della Torre , M. Gervasi , G. La Vacca , P. G. Rancoita

We discuss two extraordinary increases of cosmic ray intensity observed by Voyager 1 in the last 1.1 AU before heliopause crossing, Aug 2012 at 121.7 AU. The two increases are roughly similar in amplitude and result in a total increase of…

Solar and Stellar Astrophysics · Physics 2014-09-04 W. R. Webber , J. J. Quenby

We perform Monte Carlo simulations of cosmic ray-induced hard X-ray radiation from the Earth's atmosphere. We find that the shape of the spectrum emergent from the atmosphere in the energy range 25-300 keV is mainly determined by Compton…

Astrophysics · Physics 2008-11-26 S. Sazonov , E. Churazov , R. Sunyaev , M. Revnivtsev

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

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
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