A database of multi-year (2004–2010) quality-assured surface solar hourly irradiation measurements for the Egyptian territory

Abstract. A database containing the global and diffuse components of the surface solar hourly irradiation measured from 1 January 2004 to 31 December 2010 at eight stations of the Egyptian Meteorological Authority is presented. For three of these sites (Cairo, Aswan and El-Farafra), the direct component is also available. In addition, a series of meteorological variables including surface pressure, relative humidity, temperature, wind speed and direction is provided at the same hourly resolution at all stations. The details of the experimental sites and instruments used for the acquisition are given. Special attention is paid to the quality of the data and the procedure applied to flag suspicious or erroneous measurements is described in detail. Between 88 and 99  % of the daytime measurements are validated by this quality control. Except at Barrani where the number is lower (13 500), between 20 000 and 29 000 measurements of global and diffuse hourly irradiation are available at all sites for the 7-year period. Similarly, from 9000 to 13 000 measurements of direct hourly irradiation values are provided for the three sites where this component is measured. With its high temporal resolution this consistent irradiation and meteorological database constitutes a reliable source to estimate the potential of solar energy in Egypt. It is also adapted to the study of high-frequency atmospheric processes such as the impact of aerosols on atmospheric radiative transfer. It is planned to update regularly the current 2004–2010 database, which has been placed on the PANGAEA repository (doi:10.1594/PANGAEA.848804) and contains the individual meteorological and irradiation data files of the eight stations.