Solar radiation and terrestrial environment

Solar systems are subjected to a unique set of conditions that may alter their stability and, hence, their performance and life-cycle costs. These conditions include UV radiation, temperature, atmospheric gases and pollutants, the diurnal and annual thermal cycles, and, in concentrating systems, a high-intensity solar flux. In addition, condensation and evaporation of water, rain, hall, dust, wind, thermal expansion mismatches, etc., may impose additional problems for the performance of a solar system. These conditions and problems must be considered not only individually, but also for synergistic degradative effects that may result from their collective action on any part of the system. Since these degradative effects may also reduce the system or component performance, protective encapsulation of sensitive materials from the hostile terrestrial environment is required to provide component durability. 

Exposure to natural sources of external ionizing radiation results from the levels of cosmic and terrestrial X and gamma radiation present in the environment. Cosmic radiation at the earth s surface is affected by altitude, geomagnetic latitude, and solar modulation. For example, the dose rate at... 

The atmosphere can be considered to be a mixture of gases and particles exposed to the electromagnectic energy of the sun. An understanding of the dynamical and photochemical processes that occur in this environment requires evaluation of atmospheric radiative transfer. For example, the rate of reaction between two constituents often depends on the local temperature (see Chapter 2), which is affected by absorption, scattering, and emission of solar and terrestrial radiation. Further, solar radiation of particular energies can dissociate and ionize atmospheric molecules, producing reactive ions and radicals which, in turn, participate in many important chemical processes. 

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