Physics
Scientific paper
Sep 2004
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004jastp..66.1195w&link_type=abstract
Journal of Atmospheric and Solar-Terrestrial Physics, Volume 66, Issue 13-14, p. 1195-1203.
Physics
1
Geomagnetic Reversals, Superchrons, Orbital Forcing, Solar Activity, Cosmic Ray Flux, Spiral Arms, Carbonate Cycles, Palaeoclimatic Change
Scientific paper
Data on the relation of past climate variations and changes in the geomagnetic field can contribute to the research on a cosmic ray-climate link. This paper presents a synthesis of geological and astrophysical results about the link of magnetic field variations and Earth's climate and external forcing. On millennial timescales, geomagnetic intensity lows are apparently in phase with times of low solar magnetic activity and climate cooling. Reconstructions of quaternary continental climate systems indicate colder and dryer conditions during and after geomagnetic reversals. In the Milankovitch frequency band geomagnetic field reversals can occur in conjunction with minima in the carbonate content related to the 100ka eccentricity cycle of the Earth's orbit. A quasi 100ka cyclicity (in phase with orbital eccentricity) is discussed in the literature for both geomagnetic intensity and solar magnetic activity. On mega-cycle periods external forcing seems to play a role in the appearance of superchrons of the geomagnetic field. When applying current spiral arm models superchrons developed during times when the solar system was located between spiral arms. This suggests that the galactic environment may force the geomagnetic field to switch from its reversing mode into superchron stages probably via modulations of the Sun. Interestingly, there is a link to the structuring of magnetic fields in our galaxy. While the galactic magnetic fields between spiral arms are homogenous, the passage of the solar system through turbulent magnetic fields along the spiral arms parallels high geomagnetic reversal rates. Occurring in conjunction with a low intrinsic cosmic ray flux the superchrons probably lowered the cosmic ray flux at Earth even further. This may also have played a role in the evolution of life on Earth and the timing of some mass extinction events.
No associations
LandOfFree
External forcing of the geomagnetic field? Implications for the cosmic ray flux-climate variability does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with External forcing of the geomagnetic field? Implications for the cosmic ray flux-climate variability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and External forcing of the geomagnetic field? Implications for the cosmic ray flux-climate variability will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-797038