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Related papers: Do extragalactic cosmic rays induce cycles in foss…

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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

A ~ 62 My periodicity in fossil biodiversity has been observed in independent studies of paleontology databases over ~0.5Gy. The period and phase of this biodiversity cycle coincides with the oscillation of our solar system normal to the…

Earth and Planetary Astrophysics · Physics 2011-10-10 Dimitra Atri , Adrian L. Melott

Variations in the flux of Galactic Cosmic Rays (GCR) at Earth during the last 4.6 billion years are constructed from information about the Star Formation Rate (SFR) in the Milky Way and the evolution of solar activity. The variations of GCR…

Space Physics · Physics 2007-05-23 Henrik Svensmark

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 ability to predict times of greater galactic cosmic ray (GCR) fluxes is important for reducing the hazards caused by these particles to satellite communications, aviation, or astronauts. The 11-year solar cycle variation in cosmic rays…

Solar and Stellar Astrophysics · Physics 2015-06-15 Simon R Thomas , Mathew J Owens , Mike Lockwood

Two recent papers claimed to have found a periodic variation of the galactic cosmic ray (CR) flux over the last 1-2 Gyr, using the CR exposure ages of iron meteorites. This was attributed to higher CR flux during the passage of the Earth…

Astrophysics · Physics 2016-08-30 Knud Jahnke

The Galactic cosmic ray (GCR) intensity has been postulated by others to vary cyclically with a peak to valley ratio of ~3:1, as the Solar System moves from the Spiral Arm to the Inter-Arm regions of the Galaxy. These intensities have been…

Solar and Stellar Astrophysics · Physics 2015-06-15 T. Sloan , A. W. Wolfendale

Medvedev and Melott (2007) have suggested that periodicity in fossil biodiversity may be induced by cosmic rays which vary as the Solar System oscillates normal to the galactic disk. We re-examine the evidence for a 62 million year (Myr)…

Populations and Evolution · Quantitative Biology 2007-08-22 Bruce S. Lieberman , Adrian L. Melott

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

We construct a Galactic cosmic ray (CR) diffusion model while considering that CR sources reside predominantly in the Galactic spiral arms. We find that the CR flux (CRF) reaching the solar system should periodically increase each crossing…

Astrophysics · Physics 2008-11-26 Nir J. Shaviv

Modulation of galactic cosmic ray intensity is governed by several mechanisms including diffusion, convection, adiabatic energy losses and drift. Relative roles of these factors change in the course of an 11-year solar cycle. That can…

Solar and Stellar Astrophysics · Physics 2014-12-01 G. A. Bazilevskaya , M. S. Kalinin , M. B. Krainev , V. S. Makhmutov , A. K. Svirzhevskaya , N. S. Svirzhevsky

A decrease in the globally averaged low level cloud cover, deduced from the ISCCP infra red data, as the cosmic ray intensity decreased during the solar cycle 22 was observed by two groups. The groups went on to hypothesise that the…

Atmospheric and Oceanic Physics · Physics 2015-05-13 T. Sloan , A. W. Wolfendale

Understanding the irregular variation of the solar cycle is crucial due to its significant impact on global climates and the heliosphere. Since the polar magnetic field determines the amplitude of the next solar cycle, variations in the…

Solar and Stellar Astrophysics · Physics 2024-12-25 Pawan Kumar

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 observed variability of the cosmic-ray intensity in the interplanetary space is driven by the evolution of the Sun's magnetic activity over its 11-year quasiperiodical cycle. Investigating the relationship between solar activity indices…

Solar and Stellar Astrophysics · Physics 2022-10-13 Nicola Tomassetti , Bruna Bertucci , Emanuele Fiandrini

It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic ray exposure as the solar system oscillates perpendicular to the galactic plane. Here we…

Astrophysics · Physics 2014-11-18 A. L. Melott , D. Atri , B. C. Thomas , M. V. Medvedev , G. W. Wilson , M. J. Murray

The continuous flux of Galactic cosmic rays that bombard Earth's atmosphere creates ionizing radiation that can damage the DNA of living organisms. While this radiation on Earth is relatively constant in the short term, large and long-scale…

High Energy Astrophysical Phenomena · Physics 2025-09-05 Péter Ozsvárt , Emma Kun , Imre Bartos , Zsolt Gy. Márka , Szabolcs Márka

It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the…

Astrophysics · Physics 2007-07-11 T. Sloan , A W Wolfendale

Observations of open star clusters in the solar neighborhood are used to calculate local supernova (SN) rates for the past 510 million years (Myr). Peaks in the SN rates match passages of the Sun through periods of locally increased cluster…

Solar and Stellar Astrophysics · Physics 2012-10-11 Henrik Svensmark

Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been…

Atmospheric and Oceanic Physics · Physics 2011-08-31 Jasper Kirkby
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