Saturday, November 11, 2006

Galactic Cosmic Rays

There is a lot of discussion on the cause and effects of Cosmic rays and the inverse relationships of the sun-earth climate coupling. Proponents of AGW are of course critical as it is like Ockhams razor being wielded by Sweeny Todd through some of their virtual hypothesis .Unfortunately for them it is not one or two but the consolidated works of 5 Nobel laureates that form the heuristic theory and reality of the coupling.

In the beginning of the cosmic era is established the important role of the different particle types in the extraterrestrial and interplanetary space: galactic cosmic rays (GCR), solar cosmic rays (SCR), radiation belt and aurora particles, solar wind (SW), etc. Because of that the energetic and the variations of these particles appear as essential aspect of solar-terrestrial physics. All energy fluxes in the interplanetary space with extra solar origin are negligible small in comparison with the energy fluxes from the Sun, at least near the Earth’s orbit. But namely GCR possess maximal penetration capability to 2 kilometres into the ocean and 900 metres into the lithosphere.

Cosmic rays form the lower parts of the terrestrial and planetary ionospheres. They create in the Earth environment independent cosmic ray layer, so called C layer in the ionosphere D region, which is situated at heights 50 - 80 km (Velinov, 1966, 1968). Therefore they influence on the propagation on radiowaves, particularly in the range of medium, long and very long waves. The cosmic rays maintain the ionization not only in the ionosphere but also in the atmosphere, the hydrosphere and the lithosphere of the Earth.

CR determine the ionization rate and conductivities in the atmosphere and the ionosphere and therefore the atmospheric electric fields. The last influence the thunderstorms, Earth’s global charge and global electric circuit between the ionosphere and the ground. It is already established (Ermakov, 1992; Ermakov and Stozhkov, 2003), that the main cause of thunderstorm discharges are external atmospheric showers (EAS) of high energy primary CR particles with energy more than 1014 eV. CR produce also nuclear reactions with ground, water and air atoms. On this way cosmogenic nuclides in space, in bodies, and in atmospheres are created. Such cosmogenic isotopes are 10Be, 7Be, 3He and 3H (Dorman, 2004). All this shows the great importance of cosmic rays for the processes of solar-terrestrial relationships, solar-terrestrial physics and solar-planetary physics in the whole heliosphere.

The Sun sends to the Earth different types of radiations - photons (visible optical OPT, infrared IR, X-rays, gamma rays, etc.) and particles (the permanent SW, the sporadic SCR, etc.). The Sun also generates magnetic field, i.e. the interplanetary magnetic field IMF. The whole Solar system is radiated by GCR, which are generated in the supernovae stars and in the Nucleus of the Galaxy in the galactic center (GC). The solar wind and interplanetary magnetic fields modulate GCR with their cycles (11- and 22- years, 27-days, etc.). Besides in the magnetosphere, ionosphere and atmosphere exist 12- hour and diurnal variations. Consequently SW and IMF modulate all primary and secondary GCR particles.

However GCR determine the chemistry and electrical parameters in the atmosphere. They create ozonosphere and influence actively on O3 processes. GCR transmit to the ozonosphere their solar modulation. But the ozonosphere controls the meteorological solar constant and the thermal regime and dynamics (including the dynamics of the cloud system) of the lower atmosphere, i.e. the weather and climate (Velinov, 1998, 2000). This mechanism may be expanded still taking into account that the GCR create not only the atmospheric but the hydrosphere and lithosphere part of the ozonosphere also.

When a high-energy cosmic ray interacts with the Earth's atmosphere, it may produce an electron-positron pair with enormous velocities. The Cherenkov radiation from these charged particles is used to determine the source and intensity of the cosmic ray the very brief flash of Cherenkov radiation generated by the cascade of relativistic charged particles produced when a very high energy gamma ray strikes the atmosphere. This shower of charged particles, known as an Extensive Air Shower (EAS) is initiated at an altitude of 10-20km. The incoming gamma-ray photon undergoes pair production in the vicinity of the nucleus of an atmospheric molecule.

The electron-positron pair produced are of extremely high energy and immediately undergo Bremsstrahlung or 'Braking Radiation'. This radiation produced is itself extremely energetic, with many of the photons undergoing further pair production. A cascade of charged particles ensues which, due to its extreme energy, produces a flash of Cherenkov radiation lasting between 5 and 20 ns. The total area on the ground illuminated by this flash corresponds to many hundreds of square meters,

This animation of a single GCR proton disassembling at 15 km is a good example of the energy released.GCR


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