Cloud impacts on the transfer of Ultraviolet (UV) radiation through the atmosphere can be assessed using a cloud modification factor (CMF). The total global solar irradiation has proven to be a solid basis to derive CMF’s for the UV radiation (UV CMF). Total global irradiance is frequently measured and forecasted by numerical weather predic5 tion systems. Its advantage compared to for instance ...

The main objective of Present study is based on meteorological variables to estimate monthly Global Solar Radiation (GSR) on a horizontal surface. Monthly mean of maximum air temperature, relative humidity, sunshine hours and wind speed values between 1974 and 2008 for Tehran city in Iran (35_41N, 51_19E), are used in this study. In order to investigate the effect of each meteorological variabl...

background: in general, measurements of solar ultraviolet (uv) radiation are related to horizontal surfaces. while the hu­mans walking and standing outdoors expose to the natural solar uv radiation, their eyes, cheeks, extremities, trunks, or many other anatomical sites are close to vertical plane and random orient to different directions. in this study, we character­ized the diurnal variations...

In order to evaluate satellite and cloud cover models, it is useful to understand the short-term variability of solar radiation. This article examines at the variability of beam and global solar radiation over short time intervals. First, 5-minute data are compare with data collected 5 and 15 minutes later. Second, data collected during the middle 5minute period of an hour are compared to hourl...

This paper reviews the main factors influencing the synthesis of vitamin D, with particular focus on ultraviolet radiation exposure. On the global level, the main source of vitamin D is the sun. The effect of solar radiation on vitamin D synthesis depends to some extent on the initial vitamin D levels. At moderate to high latitudes, diet becomes an increasingly important source of vitamin D due...

Loadings of tropospheric aerosols have increased substantially over the past 150 yr as a consequence of industrial activities. These aerosols enhance reflection of solar radiation by the Earth-atmosphere system both directly, by scattering light in clear air and, indirectly, by increasing the reflectivity of clouds. The magnitude of the resultant decrease in absorption of solar radiation is est...

Precipitation and air temperature data, only, are often recorded at meteorological stations, with radiation beingmeasured at very few weather stations, especially in developing countries. Therefore there arises a need for suitablemodels to estimate solar radiation for a completion of data sets. This paper is about an evaluation of eight models foran estimation of daily solar radiation (Q) from ...

Abstract: The tilt angle with the horizon (with respect to the ground) of the solar energy system affects the amount of solar radiation received. This paper suggests a simple and universal method to obtain the optimum tilt angles by estimating the monthly mean daily global solar radiation on tilted surfaces facing directly towards the equator, which is based on monthly average daily global sola...

this study assessed the optimum water need of pepper (capsicum annuum l. cv. california wonder) and the critical irrigation level to be applied in order to achieve a reasonable economic yield in water shortage conditions. in a controlled field experiment involving five different treatments, seasonal evapotranspiration for pepper fluctuated from 89 mm in the severe stress treatment (i0.00) to 1,...