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| Titel |
On periodicities in long term climatic variations near 68° N, 30° E |
| VerfasserIn |
E. A. Kasatkina, O. I. Shumilov, M. Krapiec |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7340
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| Digitales Dokument |
URL |
| Erschienen |
In: Solar, heliospheric and external geophysical effects on the Earth’s environment: scientific and educational initiatives ; Nr. 13 (2007-08-07), S.25-29 |
| Datensatznummer |
250011697
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| Publikation (Nr.) |
 copernicus.org/adgeo-13-25-2007.pdf |
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| Zusammenfassung |
| It is generally believed that the low-frequency variability of climatic
parameters seems to be connected to solar cycles. The principal
periodicities are: 11-year (Schwabe), 22-year (Hale), 33-year (Bruckner) and
80–100-year (Gleissberg) cycles. The main heliophysical factors acting on
climate, the biosphere and the atmosphere are solar irradiance, the
intensity of solar and galactic cosmic rays (relativistic charged particles
with energies >500 MeV) changing the cloud cover of the atmosphere, and
UV-B-radiation. The 11-year and 80–90-year solar cycles are apparent in
solar radiation and galactic cosmic ray trends. At the same time the
bidecadal Hale cycle, related to a reversal of the main solar magnetic field
direction is practically absent in either solar radiation or galactic cosmic
ray variations. Besides, nobody can identify any physical mechanisms by
which a reversal in the solar magnetic field direction could influence
climate. However, the 22-year cycle has been identified in rather many
regional climatic (droughts, rainfall, tree growth near 68° N,
30° E) and temperature records all over the world. We discuss here three
possible cause of the bidecadal periodicity in climatic records, one of
which is associated with a variation of stardust flux inside the Solar
System. The most recent observations by the DUST experiment on board the
Ulysses spacecraft have shown that the solar magnetic field lost its
protective power during the last change of its polarity (the most recent
solar maximum), so that the stardust level inside of the Solar System has
been enhanced by a factor of three. It is possible that the periodic
increases of stardust in the Solar System may influence the amount of
extraterrestrial material that falls to the Earth and consequently act on
the Earth's atmosphere and climate through alteration of atmospheric
transparency and albedo. This material (interstellar dust and/or cometary
matter) may also provide nucleation sites and thereby influence
precipitation. |
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