- Novel model of atmospheric electric field (AEF) based on the idea of AEF generation due to electric charges separation in “fair weather” atmosphere is proposed.
- If thunderstorms are absent then the electric charges in the atmosphere are formed through its ionization by galactic cosmic rays (GCR).
- Light positive ions are lifted by upward currents to the upper layers of atmosphere and heavy negative aerosols fall to the Earth.
- The model provides the explanation for Carnegie curve of AEF and for some other features of atmospheric electricity; in particular, AEF behavior and Forbush decreases of GCR during geomagnetic disturbances.
- The problem of AEF secular decrease against the Earth surface temperature, the results of experiments on AEF excitation, AEF behavior during earthquakes and seismovibrators run are discussed.
The essence of our idea is that thunderstorms and strikes have impact on AEF, but they are not its main source.
According to the model charge formation (due to atmosphere ionization by GCR) and separation (due to the difference in charged aerosol falling rates) occur in “fair weather” atmosphere. In order to prove the case it is necessary, at first, to find convincing arguments that GCR can bring electric charge to the Earth, which is not less in value than the Earth looses per unit time I = dQ/dt = 103 coulomb/s.
Ion formation rate q is associated with cosmic ray flux density Р by the ratio: q = Р σ No, σ –effective cross-section of air ionization by cosmic rays, No – air molecule concentration.
Altitude distribution of electric charge density in the atmosphere (Marsh, Svensmark, 2000). As it is follows from the picture the air ionization in the part of the atmosphere, which is involved in AEF generationis due to GCR.
In the works ( atmosphere (Ermakov et al., 1997; Ermakov, Stozhkov, 2004) it was experimentally ascertained that atmospheric air ionization by cosmic rays q occurs according to the ion balance linear equation: q =β N but not to the usually applied quadratic equation q = αN2. Here α – volume recombination coefficient, β – linear recombination coefficient, these coefficients are different in value and dimension. The discovered dependence points that the relation between ion concentration in the atmosphere and cosmic ray flux is stronger (N ~ Р), than it was earlier supposed (N ~ Р1/2). This approach gives more confidence that GCR have significant impact on AEF and atmosphere conductivity current j. It is illustrated pictorially in Fig. where stable correlation between GCR flux N and j current (dQ/dt) is shown.
In the global scale there are three types of atmosphere ( particles size distribution in the troposphere: “background”, “oceanic” and “continental”. Idealized curves, exhibiting the features of these distributions are shown in Fig. (Ivlev, 1999).- The maximum aerosol concentration corresponds to the size r ≥ 0.1 mkm (from this point on we shall be interested in the particles particularly of this size).-Charged particles separation occurs on water droplets and heavy ions, that is why it is necessary to find out if there are appropriate conditions in the atmosphere for condensation and coagulation of the droplets with the radius r ≥ 0.1 mkm.
(ζ ≈ 0.25 V), η – air viscosity (η ≈ 10-5 Pа s),
σe- electroconductivity (σ ≈ 10-14 Ω-1 m-1); ЕZ ≈ 104 V/m.
ЕZ M T-1/2 exp (-T).
Еz’ ≈ [exp(-at)(1 + 2at)/а] ×(at)3/2
and assuming t =1 we obtain the relation T’/E’ ≈ 2а3/2. Revealed in measurements a equal to а = 0.06 ensures
T’/E’ = 0.03.
foF2 universal variation averaged for the years of minima (а), maxima (b) for three cycles of solar activity depending on season (c) (Kuznetsov et al., 1998).