Energy
F. O. Aweda; T. K. Samson
Abstract
This current study was conducted on rainfall and air temperature data obtained from the archive of the HelioClim website to determine the relationship between the two parameters. The study aimed at the relationship between rainfall and air temperature. The data of thirty-four (34) years spanning from ...
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This current study was conducted on rainfall and air temperature data obtained from the archive of the HelioClim website to determine the relationship between the two parameters. The study aimed at the relationship between rainfall and air temperature. The data of thirty-four (34) years spanning from 1985 to 2019 was analyzed using Mann-Kendal statistics on the trend of the rainfall series while the normality of rainfall series was determined using Kolmogorov- Smirnov test across six southwest stations of Nigeria. The results revealed the highest mean rainfall in Akure (198.9 mm) while the least rainfall in Ado-Ekiti (163.4 mm). The maximum rainfall was in Abeokuta (865.8 mm) with Iwo having the highest disparity in rainfall (SD=148.8 mm) compared with other stations. The skewness in Abeokuta (Skewness = 0.9 mm) was higher compared with Ado-Ekiti, Akure, Ibadan, Ikeja and Iwo with skewness values of 0.7 mm, 0.4 mm, 0.7 mm, 0.6 mm and 0.7 mm, respectively. The maximum air temperature was recorded in Iwo (301.7 K) and the minimum air temperature in Ado-Ekiti (293.3 K). The skewness obtained in Akure (-0.2) and Ikeja (-0.3) was less than zero indicating that air temperature decreased more than it increased in these areas while in other stations, Abeokuta (0.01), Ado-Ekiti (0.22), Ibadan (0.02) and Iwo (0.24), the skewness was greater than zero meaning that air temperature increased more than it decreased in these stations.
F. O. Aweda; S. Adebayo; T. K. Samson; I. A. Ojedokun
Abstract
In this study, the net radiation was estimated using a simple straightforward expression proposed by different researchers, which is based on the principle of the Fourier Series Technique. The estimation of net radiation of Iwo ( ) from the data collected from the archive of HelioClim satellite MERRA- ...
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In this study, the net radiation was estimated using a simple straightforward expression proposed by different researchers, which is based on the principle of the Fourier Series Technique. The estimation of net radiation of Iwo ( ) from the data collected from the archive of HelioClim satellite MERRA- 2 (i.e. global solar radiation and air temperature) was done on the real and imaginary measurements. The result of both real and imaginary radiation at maximum revealed ( ) and minimum at about ( ), while solar radiation and temperature revealed about ( ) and 299K maximum and minimum ( ) and 297.7K, respectively. Statistically, the result indicated that the regression coefficient of 3.959 with t- statistics of 3.34 and p < 0.05 indicates that for every 1K increase in air temperature, solar radiation will increase by 3.959, which shows that both solar radiation and temperature have a significant effect on net radiation. Therefore, the researchers concluded that Iwo had maximum real net radiation in February with months such as January, March, July, August, October and December as minimum radiation while imaginary radiation had its maximum and minimum in September and August respectively.
D. Bensahal; A. Yousfi
Abstract
This paper is focusing on hourly air temperature estimation model (MAT) using available meteorological measured data located in Laghouat (Algeria). The hourly air temperature defined by the present model can be calculated at any time of the night or the day period based on atmospheric pressure, global ...
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This paper is focusing on hourly air temperature estimation model (MAT) using available meteorological measured data located in Laghouat (Algeria). The hourly air temperature defined by the present model can be calculated at any time of the night or the day period based on atmospheric pressure, global solar radiation and relative humidity data. This work was compared with three published models from the literature as: Wave, Idliman and Double cosine. Fifteen months of hourly atmospheric pressure, global solar radiation, relative humidity and air temperature data collected during the period (January 2015 to March 2016) were used to test the accuracy of the various models studied. The analysis of the days selected randomly showed that the MAT model gave substantially good fit to the observed data. The RMSE of the MAT model is less than 0.5 oC during all the period of study than the other models studied ranged in the interval (2 oC, 4 oC). The estimated results are compared to the measured ones by using statistical parameters tests such as the mean bias error (MBE), the mean percentage error (MPE), the mean absolute error (MAE), the root mean square error (RMSE) and the coefficient of determination (R2).
