Study the Relation of Cloud Cover with Evaporation and Solar Radiation over Baghdad City

Abstract

Cloud cover effects on most other meteorological variables. It effects on the amount of radiation entering the boundary layer of the atmosphere and thus it controls the amount of energy within this range. Evaporation is also an important factor in the formation of clouds and directly affects the energy equation. This study was based on daily data of cloud cover and evaporation values taken from Iraqi meteorological organization and seismology for the period 2000 to 2005 for the city of Baghdad, as well as the solar radiation data of the three components (direct - diffuse - reflected) and the same location and period time period taken from European center of solar energy services for professionals study (soda), monthly and annual rates were calculated to show the correlation between these variables. 

To carry out statistical operations and convert the values of the cloud cover to the proportions of eight parts to indicate the proportion of clouds in the sky and drawing diagrams, the results showed that there is a significant effect of the evaporation processes on the formation of the cloud cover. High evaporation values are associated with high values of the cloud cover and have a high positive correlation coefficient value hits (0.74). The results showed that the cloud cover values are inversely proportional to the direct and diffused radiation compounds and have a negative correlation coefficient of  (-0.93). This effect is less on the reflected radiation component. In general, the cloud cover can be used to estimate the values of some other meteorological variables, especially in winter seasons.