Evaluation of Monthly Mean Sunshine Duration for Baghdad City

Abstract

Sunshine duration is one of the significant factors that influence on the total annual global solar radiation. However compare four different methods Meteorological data system. Two of them are observed data that are Iraqi Meteorological Organization and Baghdad Airport, and measuremed data that are; European Center for Media-Range Weather Forecasts (ECMWF-ERA-40), and Sunrise Sunset Calculator.results shown that, the observation data is less than measurement data by two hours. The maximum sunshine duration came from ECMWF that was 15 hours and 12 minutes in June, and the follow maximum value in May and July. The sunshine duration limited between summer (maximum value) and winter (minimum value). These results show that ECMWF is the best and more accurate data for evaluate the sunshine duration.