Journal of Earth Sciences and Geotechnical Engineering

Clear Sky Absorption of Solar Radiation by the Average Global Atmosphere

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  • Abstract

    The author has analyzed shortwave (SW) absorption of the annual average global atmosphere (AGA) in the clear sky conditions utilizing spectral analysis methods. A modified zenith angle has been used in calculating the average zenith values for five atmospheric models covering three climate zones of the Earth. The absorption flux value of 67.71 Wm-2 of this study is very close to the value of 69 Wm-2 found in the energy balance analysis based on the observational data. It means that the absorption due to the aerosols would be 1.29 Wm-2, which is close to the values 1.6 – 2.4 Wm-2 calculated in different studies for aerosol absorption in the atmosphere. This result shows that there is no excessive absorption in the clear sky conditions when calculating annual global value. When the effective global zenith value of 51.38 degrees has been applied to the one dimensional (1D) model in the modified mid-latitude atmosphere corresponding to the AGA conditions, the results are similar to the results based on the five different atmospheric models applied in three climate zones of the Earth. The 1D model has been applied for finding basic relationships in SW absorption phenomenon. One result is that the contribution of water is 77.2 % and ozone’s contribution is 19.5 %. The results are comparable to the traditional radiation transfer models developed for SW absorption calculations.