scholarly journals Evaluating the Performance of Autoregressive Model for Solar Radiation Forecasting

2021 ◽  
Vol 5 (2) ◽  
pp. 444-455
Author(s):  
M. Ocholi ◽  
B. Adeyemi ◽  
O.O. Omojola ◽  
C.S. Samuel
Keyword(s):  
Solar Radiation ◽  
Autoregressive Model ◽  
Coastal Region ◽  
Global Solar Radiation ◽  
Periodic Component ◽  
Port Harcourt ◽  
Impressive Result ◽  
Residual Series ◽  
Partial Autocorrelation Function ◽  
Q Statistic

The solar radiation data taken from 14 meteorological stations in Nigeria has been analyzed. The periodic component of the data which covered a period of 13 (mostly 1977-1989) years was removed via Fourier analysis while the residual series was subjected to autoregressive analysis. It was evident from the t-test and autocorrelation plots of the modified (i.e. without the periodic component) series that there exist significant persistence at nine stations including Sokoto, Nguru, Kano, Maiduguri, Bauchi, Yola, Minna, Ibadan, and Benin. The autocorrelation at Jos, Bida, Ikeja, Enugu and Port Harcourt were however found to be insignificant. As the sample partial autocorrelation function cuts off after lag 1, a non-seasonal autoregressive model of order 1, AR (1), was identified for stations with autocorrelation. The Q-statistic of error series suggested that the models were adequate as identified. Moreover, the exploratory plots of the model residual series showed agreement with the quantitative statistics and thus enforces the inference that the models were adequate for monthly mean daily global solar radiation forecasts at some of the study stations. It is interesting to note that all the stations within the sub-sahelian region showed significant persistence whereas all the stations in the coastal region except Benin were found with insignificant autocorrelation. Expectedly, the performance evaluation of the model gave impressive result for the stations within the sub-sahelian region but a relatively weak result for the coastal region. The result for the midland region was mixed whereas it was difficult to conclude on the Guinea savannah region with result from only one station.

scholarly journals Relationship between photosynthetically active radiation with global solar radiation using empirical model over selected climatic zones in Nigeria

2017 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Nwokolo Samuel Chukwujindu ◽  
Ogbulezie Julie C. ◽  
John-Jaja Sylvia Alwell
Keyword(s):  
Solar Radiation ◽  
Empirical Model ◽  
Photosynthetically Active Radiation ◽  
Global Solar Radiation ◽  
Hadley Cell ◽  
Circulation System ◽  
Climatic Zones ◽  
Active Radiation ◽  
North East ◽  
Port Harcourt

In this study, relationship between photosynthetically active radiation (PAR) and global solar radiation (H) over selected climatic zones in Nigeria using 22-years data (July 1983 – June 2005) was analysed. Empirical model was employed as the baseline for theoretical formulation and estimation of the ratio of PAR/H over climatic zones in Nigeria. From the estimated values, the seasonal PAR/H ranged from 1.946-2.005, 1.909-1.955, 1.968-2.039, 1.987-2.060, 1.961-2.041, 1.928-1.984 and 1.946-2.005 in rainy season, and the high values were due to low influence from clearness index, harmattan dust and pyrogenic aerosols from regional biomass burning compared with 1.906-1.923, 1.905-1.917, 1.927-1.952, 1.950-1.999, 1.971-1.985 and 1.889-1.923 recorded in dry season as a result of combined high influence from cloudiness, pyogenic aerosols and harmattan dust with annual mean values of 1.943, 1.921, 1.975, 2.007, 1.986 and 1.936 for Ilorin, Sokoto, Abeokuta, Port Harcourt, Enugu and Gusau respectively. The annual ratio of PAR/H revealed that there is an evidence increase of the values from North-East (Gusau) to South-South (Port Harcourt). These variations were mainly due to trends in cloudiness and associated atmospheric moisture with the movement of the Hadley cell circulation system along the equatorial line. From the analysed results, the model was found suitable and meteorologically reliable to estimate PAR/H accurately from commonly available H data when compared with results within and beyond tropical locations in Nigeria.

scholarly journals Detrended Multiple Cross-Correlation Coefficient applied to solar radiation, air temperature and relative humidity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Solar Energy ◽  
Correlation Coefficient ◽  
Air Temperature ◽  
Cross Correlation ◽  
Global Solar Radiation ◽  
Meteorological Variables ◽  
Hourly Data ◽  
Cross Correlations

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.

scholarly journals Solar Climate Features Taking into Account the Morphometric Conditions of the Area and the Possibility of Using Them in Heliotherapy on the Example of the Cieplice and Kołobrzeg Health Resorts (Poland)

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 383
Author(s):  
Dawid Szatten ◽  
Mirosław Więcław
Keyword(s):  
Solar Radiation ◽  
Land Cover ◽  
Human Activity ◽  
Sunshine Duration ◽  
Quantitative Relationship ◽  
Global Solar Radiation ◽  
Main Element ◽  
Entropy Model ◽  
Health Treatment ◽  
Health Resorts

Global solar radiation is an important atmospheric stimulus affecting the human body and has been used in heliotherapy for years. In addition to environmental factors, the effectiveness of global solar radiation is increasingly influenced by human activity. This research was based on the use of heliographic and actinometric data (1996–2015) and the model distribution of global solar radiation to determine the possibility of heliotherapy with the example of two health resorts: Cieplice and Kołobrzeg (Poland). The solar features of health resorts (sunshine duration and global solar radiation) were characterized, and they were correlated with the spatial distribution of global solar radiation data obtained with the use of remote sensing techniques (System for Automated Geoscientific Analyzes-SAGA), including COoRdination and INformation on the Environment (CORINE) land cover (CLC) data. Using the maximum entropy model (MaxEnt), a qualitative and quantitative relationship between morphometric parameters and solar climate features was demonstrated for individual land cover types. Studies have shown that the period of late spring and summer, due to the climate’s solar features, is advisable for the use of heliotherapy. The human activity that determines the land cover is the main element influencing the spatial differentiation of the possibilities of using this form of health treatment. It also affects topographic indicators shown as significant in the MaxEnt predictive model. In general, areas with high openness were shown as predisposed for health treatment using global solar radiation, which is not consistent with areas commonly used for heliotherapy. The conducted research has shown the need for an interdisciplinary approach to the issue of heliotherapy, which will contribute to the optimization of the use of this form of health treatment from the perspective of climate change and human pressure.

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