PROBLEMS OF GEOCOSMOS

Proceedings of the 7th International Conference "Problems of Geocosmos" (St. Petersburg, Russia, 26-30 May 2008)
g, then substituting these values into mg = eZE, where E – vertical atmosphere electric field, Е ≈ 1V/m, еZ –
a dust particle charge, Z = 1000 one can see that this particle doesn’t precipitate in the gravitational field.
Earlier it was considered to be the fact that solid eruptive fragments are limited to the larger size
fractions, but it is reported that he 1986 plume of Mt. St. Augustine (Alaska) contained silicates in all
fractions down to 0.1 mm and large explosive eruptions transport particles higher into the atmosphere,
leading to an extended lifetime compared to equivalent lower level emissions [5].
Loss of geomagnetic field shielding during reversals and excursions as follows from our estimations of
cosmic rays flux occurs during field excursions (Fig.6). Here, density (J) of the cosmic rays (CR) flux
Fig.6. Loss of geomagnetic field shielding affecting the cosmic rays flux intensity
as protons in relation to CR energy Е: 1 – galactic CR; 2 - Sun CR; 3 – protons flux within radiation belt; 4 –
anomalous CR. Left scale: h –altitude the CR protons ionizing atmosphere penetrate [14]. Top scale:
magnitude of geomagnetic field module B (module of the modern field is equal to 1) corresponding to cut off
energy of CR protons with energy E. (B equal to 1 corresponds to Е = 10 GeV). As it is seen from the Fig.6
the density of the cosmic rays flux raises some orders under the some-times decrease of the field module.
The ionizing effect of the cosmic rays flux increases and its climate forcing depends on the stratosphere
conditions. As it is shown in Fig.1 if the excursion starts in transparent atmosphere then ionizing atmosphere
the cosmic rays flux increase generates condensation nuclei and origin of aerosols which are backscattering
solar radiation and climate cooling arises. The dusty atmosphere conditions before the excursion are
vanished by cosmic rays generation of condensation nuclei and the climate warming starts.
Linking increased volcanism activity [13] and geomagnetic field excursions we operated from the hot
Earth theory, being evolved by Kuznetsov V.V. [15]. The theory states that the geomagnetic field excursions
are identified with phase changes at the Earth inner core boundary and this impulse quickly reaches the Earth
surface. Considering increased volcanism activity to be generated after geodynamic impulse initiated by the
Earth expansion or collapse it is possible to estimate a time t of the mantle substance viscous-elastic
relaxation: t = μ/G, here μ – viscosity, а G – elasticity module. μ is estimated to fall within the range of
1021 – 1022 Pa s and G - 109 ÷ 1010 Pa. Then t ≈ 1012 s = 30 000 years and the geomagnetic field
excursions are 20 – 30 kyr ahead periods of increased volcanism activity.
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