Satellite derived solar irradiance over 25 locations in the 5 climatic zones of Nigeria (tropical rainforest TRF, Guinea savannah GS, Sahel savannah SHS, Sudan savannah SUS, and Mangrove swamp forest MSF) was analyzed. To justify its use, the satellite data was tested for goodness of agreement with ground measured solar radiation data using 26-year mean monthly and daily data over 16 locations in the 5 climatic zones. The well-known R 2 , RMSE, MBE, and MPE statistical tests were used and good agreement was found. The 25 locations were grouped into the 5 climatic zones. Frequency distribution of global solar irradiance was done for each of the climatic zones. This showed that 46.88%, and 40.6% of the number of days (9794) over TRF and MSF, respectively, had irradiation within the range of 15.01-20.01 MJ/m 2 /day. For the GS, SHS, and SUS, 46.19%, 55.84% and 58.53% of the days had total irradiation within the range of 20.01-25.01 MJ/m 2 /day, respectively. Generally, in all the climatic zones, coefficients of variation of solar radiation were high and mean values were low in July and August. Contour maps showed that high and low values of global solar irradiance and clearness index were observed in the Northern and Southern locations of Nigeria, respectively.

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This paper describes long-term spatiotemporal trends in extreme significant wave height (SWH) in the South China Sea (SCS) based on 30-year wave hindcast. High-resolution reanalysis wind field data sets are employed to drive a spectral wave model WAVEWATCH III™ (WW3). The wave hindcast information is validated using altimeter wave information (Topex/Poseidon). The model performance is satisfactory. Subsequently, the trends in yearly/seasonal/monthly mean extreme SWH are analyzed. Results showed that trends greater than 0.05 m yr−1are distributed over a large part of the central SCS. During winter, strong positive trends (0.07–0.08 m yr−1) are found in the extreme northeast SCS. Significant trends greater than 0.01 m yr−1are distributed over most parts of the central SCS in spring. In summer, significant increasing trends (0.01–0.05 m yr−1) are distributed over most regions below latitude 16°N. During autumn, strong positive trends between 0.02 and 0.08 m yr−1are found in small regions above latitude 12°N. Increasing positive trends are found to be generally significant in the central SCS in December, February, March, and July. Furthermore, temporal trend analysis showed that the extreme SWH exhibits a significant increasing trend of 0.011 m yr−1. The extreme SWH exhibits the strongest increasing trend of 0.03 m yr−1in winter and showed a decreasing trend of −0.0098 m yr−1in autumn.

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This study utilizes a 30-year (1980-2009) 10 m wind field dataset obtained from the European Center for Medium Range Weather Forecast to investigate the wind energy potential in the East China Sea (ECS) by using Weibull shape and scale parameters. The region generally showed good wind characteristics. The calculated annual mean of the wind power resource revealed the potential of the region for large-scale grid-connected wind turbine applications. Furthermore, the spatiotemporal variations showed strong trends in wind power in regions surrounding Taiwan Island. These regions were evaluated with high wind potential and were rated as excellent locations for installation of large wind turbines for electrical energy generation. Nonsignificant and negative trends dominated the ECS and the rest of the regions; therefore, these locations were found to be suitable for small wind applications. The wind power density exhibited an insignificant trend in the ECS throughout the study period. The trend was strongest during spring and weakest during autumn.