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Related papers: Solar Activity and Cloud Opacity Variations: A Mod…

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The shadowing effect of the Moon and Sun in TeV cosmic rays has been measured with high statistical significance by several experiments. Unlike particles from directions close to the Moon, however, charged particles passing by the…

High Energy Astrophysical Phenomena · Physics 2019-08-28 Frederik Tenholt , Julia Becker Tjus , Paolo Desiati

This study presents the continuation of the analysis of variations of atmospheric and space weather parameters above Iberian Peninsula along two years near the 24th solar cycle maximum presented in Morozova et al. [2016]. Previously, the…

Atmospheric and Oceanic Physics · Physics 2020-06-14 Anna L. Morozova , Paulo Ribeiro , Juan Jose Blanco , Tatiana V. Barlyaeva

Observations of the emission of the carbon cycle species (C, C+ CO) are commonly used to diagnose gas properties in the interstellar medium but are significantly sensitive to the cosmic-ray ionization rate. The carbon-cycle chemistry is…

Astrophysics of Galaxies · Physics 2022-03-14 Brandt A. L. Gaches , Thomas G. Bisbas , Shmuel Bialy

The short term variability of the Galactic cosmic ray flux (CRF) reaching Earth has been previously associated with variations in the global low altitude cloud cover. This CRF variability arises from changes in the solar wind strength.…

Astrophysics · Physics 2009-11-07 Nir J. Shaviv

Chemistry in diffuse molecular clouds relies primarily on rapid ion-molecule reactions. Formation of the initial ions, H$^+$ and H$_2^+$, is dominated by cosmic-ray ionization of H and H$_2$, making the cosmic-ray ionization rate (denoted…

We calculate the hydrogen and helium-ionizing radiation escaping star-forming molecular clouds, as a function of the star cluster mass and compactness, using a set of high-resolution radiation-magneto-hydrodynamic simulations of star…

Astrophysics of Galaxies · Physics 2020-01-29 Chong-Chong He , Massimo Ricotti , Sam Geen

Atmospheres regulate the planetary heat loss and therefore influence planetary thermal evolution. Uncertainty in a giant planet's thermal state contributes to the uncertainty in the inferred abundance of heavy elements it contains. Within…

Earth and Planetary Astrophysics · Physics 2024-04-10 Anna Julia Poser , Nadine Nettelmann , Ronald Redmer

Brown dwarfs and giant gas extrasolar planets have cold atmospheres with a rich chemical compositions from which mineral cloud particles form. Their properties, like particle sizes and material composition, vary with height, and the mineral…

Earth and Planetary Astrophysics · Physics 2016-06-22 Ch. Helling , P. B. Rimmer , I. M. Rodriguez-Barrera , Kenneth Wood , G. B. Robertson , C. R. Stark

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

Chromospheric plages are distributed between mid-latitude and the Equator and never close to the Poles. Therefore, we suspect that the inclination angle of the solar rotation axis has an impact on the observable chromospheric emission. We…

Solar and Stellar Astrophysics · Physics 2024-10-16 G. Vanden Broeck , S. Bechet , G. Rauw , F. Clette

Intending to solve the decade old problem of solar opacity, we report substantial photoabsorption uncertainty due to the effect of ion-ion correlations. By performing detailed opacity calculations of the solar mixture, we find that taking…

Solar and Stellar Astrophysics · Physics 2018-03-01 Menahem Krief , Yair Kurzweil , Alexander Feigel , Doron Gazit

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

We assume a distribution of clouds optically thick for electron scattering (OTCM) which are moderately optically thin for absorption and we consider them as a model of the mean quasar spectrum of Laor et al. (1997). We show that the model…

Astrophysics · Physics 2007-05-23 B. Czerny , A. -M. Dumont

Cosmic rays are the only agent capable of ionizing the interior of dense molecular clouds and, thus, they are believed to play an essential role in determining the physical and chemical evolution of star-forming regions. In this work, we…

High Energy Astrophysical Phenomena · Physics 2024-02-09 Vo Hong Minh Phan , Enrico Peretti , Pierre Cristofari , Antoine Gusdorf , Philipp Mertsch

We simulated the modulation of the interstellar neutral (ISN) He, Ne, and O density and pick-up ion (PUI) production rate and count rate along the Earth's orbit over the solar cycle from 2002 to 2013 to verify if solar cycle-related effects…

Solar and Stellar Astrophysics · Physics 2016-04-08 Justyna M. Sokół , Maciej Bzowski , Marzena A. Kubiak , Eberhard Möbius

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

We demonstrate that ionization of $\text{H}_2$ by dark matter in dense molecular clouds can provide strong constraints on the scattering strength of dark matter with electrons. Molecular clouds have high UV-optical attenuation, shielding…

High Energy Physics - Phenomenology · Physics 2023-08-28 Anirudh Prabhu , Carlos Blanco

The solar wind (SW) and the extreme ultraviolet (EUV) radiation modulate fluxes of interstellar and heliospheric particles inside the heliosphere both in time and in space. Understanding this modulation is necessary to correctly interpret…

Space Physics · Physics 2020-08-19 Justyna M. Sokół , D. J. McComas , M. Bzowski , M. Tokumaru

Despite recent major advances, the opacity remains a source of substantial uncertainty in the calculation of solar models, and hence of solar oscillation frequencies. Hence it is of substantial interest to investigate the sensitivity of…

Astrophysics · Physics 2009-09-25 S. C. Tripathy , J. Christensen-Dalsgaard

Variation in high energy cosmic rays (HECRs) has been proposed to explain a 62 My periodicity in terrestrial fossil biodiversity. It has been suggested that the infall of our galaxy toward the Virgo cluster could generate an extragalactic…

Earth and Planetary Astrophysics · Physics 2010-06-22 Dimitra Atri , Brian C. Thomas , Adrian L. Melott , University of Kansas , Washburn University