Testing the Link Between Terrestrial Climate Change and Galactic Spiral Arm Transit

Overholt, Andrew C.; Melott, Adrian L.; Pohl, M.

doi:10.1088/0004-637x/705/2/l101

Cited by 33 publications

(27 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More details on the CR-climate connection can be found in Scherer et al (2006). Although we do not state here that we adhere to this view in all aspects (see, e.g., the critical remarks in Overholt et al 2009), we think that it gives a further interesting motivation to study the Galactic CR distribution, especially its longitudinal structure, in greater detail. The aim of this investigation is to calculate Galactic CR spectra at different positions along the Sun's orbit around the Galactic center and to analyze the influence of anisotropic diffusion on the longitudinal cosmic ray distribution.…”

Section: Introductionmentioning

confidence: 85%

Anisotropic diffusion of Galactic cosmic ray protons and their steady-state azimuthal distribution

Effenberger

Fichtner

Scherer

et al. 2012

A&A

View full text Add to dashboard Cite

Galactic transport models for cosmic rays involve the diffusive motion of these particles in the interstellar medium. Owing to the large-scale structured Galactic magnetic field, this diffusion is anisotropic with respect to the local field direction. We included this transport effect along with continuous loss processes in a quantitative model of Galactic propagation for cosmic ray protons that is based on stochastic differential equations. We calculated energy spectra at different positions along the Sun's Galactic orbit and compared them to the isotropic diffusion case. The results show that a larger amplitude of variation and different spectral shapes are obtained in the introduced anisotropic diffusion scenario, which in turn emphasizes the need for accurate Galactic magnetic field models.

show abstract

Section: Introductionmentioning

confidence: 85%

Anisotropic diffusion of Galactic cosmic ray protons and their steady-state azimuthal distribution

Effenberger

Fichtner

Scherer

et al. 2012

A&A

View full text Add to dashboard Cite

show abstract

“…The simultaneous action of the heliomagnetic and the geomagnetic fields has been one of the difficulties in determining clear evidence of the effect of solar activity on climate variation (Dorman, 2012;Lockwood, 2012). Furthermore, there are many studies based on climatic and proxy data analysis that are in agreement with the GCR-climate relationship (e.g., Miyahara et al, 2008;Souza Echer et al, 2012;Svensmark, 2012) and other studies that disagree with this relationship (e.g., Wagner et al, 2001;Overholt et al, 2009;Erlykin and Wolfendale, 2011). Experimental results indicate that GCRs may play an important role in climate modulation (Enghoff et al, 2011;Kirkby et al, 2011;Pedersen et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Evidence for cosmic ray modulation in temperature records from the South Atlantic Magnetic Anomaly region

Frigo

Pacca²,

Filho³

et al. 2013

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. Possible direct or indirect climatic effects related to solar variability and El Niño-Southern Oscillation (ENSO) were investigated in the southern Brazil region by means of the annual mean temperatures from four weather stations 2 degrees of latitude apart over the South Atlantic Magnetic Anomaly (SAMA) region. Four maximum temperature peaks are evident at all stations in 1940, 1958, 1977 and 2002. A spectral analysis indicates the occurrence of periodicities between 2 and 7 yr, most likely associated with ENSO, and periodicities of approximately 11 and 22 yr, normally associated with solar variability. Cross-wavelet analysis indicated that the signal associated with the 22 yr solar magnetic cycle was more persistent in the last decades, while the 11 yr sunspot cycle and ENSO periodicities were intermittent. Phase-angle analysis revealed that temperature variations and the 22 yr solar cycle were in anti-phase near the SAMA center. Results show an indirect indication of possible relationships between the variability of galactic cosmic rays and climate change on a regional scale.

show abstract

“…It has already been shown by Overholt et al (2009) that the peaks and troughs in the Shaviv distribution do not correspond to crossings of the SA in the Galaxy. Here we show that the estimated intensity variations from the Shaviv distribution are also unrealistic, if we use conventional assumptions of the GCR parameters.…”

Section: Discussionmentioning

confidence: 90%

Cosmic rays and climate change over the past 1000 million years

Sloan

Wolfendale

2013

New Astronomy

View full text Add to dashboard Cite

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 correlated with global temperatures and used to support the hypothesis of GCR induced climate change. In this paper we show that the model used to deduce such a large ratio of Arm to Interarm GCR intensity requires unlikely values of some of the GCR parameters, particularly the diffusion length in the interstellar medium, if as seems likely to be the case, the diffusion is homogeneous. Comparison is made with the existing gamma ray astronomy data and this also indicates that the ratio is not large. The variation in the intensity is probably of order 10 -20% and should be no more than 30% as the Solar System moves between these two regions, unless the conventional parameters of the GCR are incorrect. In addition we show that the variation of the GCR intensity, as the trajectory of the Solar System oscillates about the Galactic Plane, is too small to account for the extinctions of species as has been postulated unless, again, conventional assumptions about the GCR parameters are not correct.

show abstract

Testing the Link Between Terrestrial Climate Change and Galactic Spiral Arm Transit

Cited by 33 publications

References 27 publications

Anisotropic diffusion of Galactic cosmic ray protons and their steady-state azimuthal distribution

Anisotropic diffusion of Galactic cosmic ray protons and their steady-state azimuthal distribution

Evidence for cosmic ray modulation in temperature records from the South Atlantic Magnetic Anomaly region

Cosmic rays and climate change over the past 1000 million years

Contact Info

Product

Resources

About