Modelling Net Radiative Measurement of Meteorological Parameters Using MERRA-2 Data in Sub-Sahara African Town

Document Type : Original Article


1 Physics and Solar Energy Programme, College of Agriculture, Engineering and Science, Bowen University, Iwo, Osun State, Nigeria

2 Electrical and Electronics Programme, College of Agriculture, Engineering and Science, Bowen University, Iwo, Osun State, Nigeria

3 Statistics Programme, College of Agriculture, Engineering and Science, Bowen University, Iwo,Osun State, Nigeria


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.


1.   An, N., Hemmati, S., and Cui, Y.-J. 2017. “Assessment of the methods for determining net radiation at different time-scales of meteorological variables.” Journal of Rock Mechanics and Geotechnical Engineering, 9(2), pp.239–246.
2.   O. Jegede, O. 1997. “Estimating Net Radiation from Air Temperature for Diffusion Modelling Applications in a Tropical Area.” Boundary-Layer Meteorology, 85(1), pp.161–173.
3.   Berkowicz, R., Olesen, H. R., and Torp, U. 1986. “The Danish Gaussian   Air   Pollution   Model   (Oml):   Description,   Test  and Sensitivity Analysis in View of Regulatory Applications.” In Air Pollution Modeling and Its Application V (pp. 453–481). Boston, MA: Springer US.
4.   Van Ulden, A. P., and Holtslag, A. A. M. 1985. “Estimation of Atmospheric Boundary Layer Parameters for Diffusion Applications.” Journal of Climate and Applied Meteorology, 24(11), pp.1196–1207.;2
5.   Evett, S., Prueger, J., and Tolk, J. 2011. “Water and Energy Balances in the Soil–Plant–Atmosphere Continuum.” In Handbook of Soil Sciences: Properties and Processes (pp. 1–44). CRC Press: Boca Raton, FL, USA,. Retrieved from
6.   Halldin, S., and Lindroth, A. 1992. “Errors in Net Radiometry: Comparison and Evaluation of Six Radiometer Designs.” Journal of Atmospheric and Oceanic Technology, 9(6), pp.762–783.;2
7.   Wrightl, J. L., Jensen, M. E., and Asce, M. 1972. “Peak water requirements of crops in southern Idaho.” roceedings of the American Society of Civil Engineers, Journal of the Irrigation and Drainage Division, 98(IR2), pp.193–201. Retrieved from
8.   Brutsaert, W. 1975. “The Roughness Length for Water Vapor Sensible Heat, and Other Scalars.” Journal of the Atmospheric Sciences, 32(10), pp.2028–2031.;2
9.   Doorenbos, J. 1977. Guidelines for predicting crop water requirements (Vol. 24). Food and Agriculture organization (FAO) irrigation and drainage paper. Retrieved from
10. Weiss, A. 1982. “An Experimental Study of Net Radiation, Its Components and Prediction 1.” Agronomy Journal, 74(5), pp.871–874.
11. Jensen, M. E., Burman, R. D., and Allen, R. G. 1990. Evapotranspiration and Irrigation Water Requirements. American Society of Civil Engineers, New York, NY. Retrieved from
12. Brutsaert, W. 1982. Evaporation into the atmosphere: theory, history and applications. Evaporation into the Atmosphere. Springer Netherlands.
13. Ortega-Farias, S., Antonioletti, R., and Olioso, A. 2000. “Net radiation model evaluation at an hourly time step for mediterranean conditions.” Agronomie, 20(2), pp.157–164.
14. Bisht, G., Venturini, V., Islam, S., and Jiang, L. 2005. “Estimation of the net radiation using MODIS (Moderate Resolution Imaging Spectroradiometer) data for clear sky days.” Remote Sensing of Environment, 97(1), pp.52–67.
15. Saito, H., Šimůnek, J., and Mohanty, B. P. 2006. “Numerical Analysis of Coupled Water, Vapor, and Heat Transport in the Vadose Zone.” Vadose Zone Journal, 5(2), pp.784–800.
16. Cui, Y. J., Gao, Y. B., and Ferber, V. 2010. “Simulating the water content and temperature changes in an experimental embankment using meteorological data.” Engineering Geology, 114(3–4), pp.456–471.
17. Wright, J. L. 1982. “New Evapotranspiration Crop Coefficients.” Journal of the Irrigation and Drainage Division, 108(1), pp.57–74. Retrieved from
18. Allen, R. G., Pereira, L. S., and Raes, D. 1998. Crop evapotranspiration-Guidelines for computing crop water requirements, Food and Agriculture organization (FAO) irrigation and drainage paper. Retrieved from
19. Brunt, D. 1932. “Notes on radiation in the atmosphere. I.” Quarterly Journal of the Royal Meteorological Society, 58(247), pp.389–420.
20. Idso, S. B. 1981. “A set of equations for full spectrum and 8- to 14-μm and 10.5- to 12.5-μm thermal radiation from cloudless skies.” Water Resources Research, 17(2), pp.295–304.
21. Goutorbe, J.-P., Lebel, T., Tinga, A., Bessemoulin, P., Brouwer, J., Dolman, A. J., Engman, E. T., Gash, J. H. C., Hoepffner, M., Kabat, P., Kerr, Y. H., Monteny, B., … Wallace, J. S. 1994. “HAPEX-Sahel: a large-scale study of land-atmosphere interactions in the semi-arid tropics.” Annales Geophysicae, 12(1), pp.53–64.
22. Wallace, J. S., Gash, J. H. C., and Icrisat, M. V. K. S. 1990. “Preliminary measurements of net radiation and evaporation over bare soil and fallow bushland in the Sahel.” International Journal of Climatology, 10(2), pp.203–210.
23. Jegede, O. O. 1997. “Diurnal variations of net radiation at a tropical station ? Osu; Nigeria.” Theoretical and Applied Climatology, 58(3–4), pp.161–168.
24. Jegede, O. O. 1997. “Daily averages of net radiation measured at Osu, Nigeria in 1995.” International Journal of Climatology, 17(12), pp.1357–1367.;2-3
25. Holtslag, A. A. M., and Van Ulden, A. P. 1983. “A Simple Scheme for Daytime Estimates of the Surface Fluxes from Routine Weather Data.” Journal of Climate and Applied Meteorology, 22(4), pp.517–529.;2
26. Collier, L. R., and Lockwood, J. G. 1974. “The estimation of solar radiation under cloudless skies with atmospheric dust.” Quarterly Journal of the Royal Meteorological Society, 100(426), pp.678–681.
27. Kasten, F., and Czeplak, G. 1980. “Solar and terrestrial radiation dependent on the amount and type of cloud.” Solar Energy, 24(2), pp.177–189.
28. Paltridge, G. W., and Platt, M. R. 1976. “Radiative Processes in Meteorology and Climatology.” Radiative process in meteorology and climatology, 5. Retrieved from
29. Arnfield, A. J. 1979. “Evaluation of empirical expressions for the estimation of hourly and daily totals of atmospheric longwave emission under all sky conditions.” Quarterly Journal of the Royal Meteorological Society, 105(446), pp.1041–1052.
30. Holtslag, A. A. M. 1987. Surface fluxes and boundary layer scaling : models and applications. PhD thesis, All Wageningen University, 151, Natuur- en weerkunde,. Retrieved from
31. Kenisarin, M., and Tkachenkova, N. 1992. “Estimation of solar radiation from ambient air temperature.” Applied Solar Energy, 28(4), pp.66–70. Retrieved from
32. Baumgartner, J., Höltinger, S., and Schmidt, J. 2018. “Evaluation of technical modelling approaches for data pre-processing in machine learning wind power generation models.” Geophysical Research Abstracts, 20, pp.2018–14305. Retrieved from
33. Jegede, O. O., Ogolo, E. O., and Aregbesola, T. O. 2006. “Estimating net radiation using routine meteorological data at a tropical location in Nigeria.” International Journal of Sustainable Energy, 25(2), pp.107–115.
34. Aweda, F. O., Oyewole, J. A., Fashae, J. B., and Samson, T. K. 2020. “Variation of the Earth’s Irradiance over Some Selected Towns in Nigeria.” Iranian (Iranica) Journal of Energy and Environment, 11(4), pp.301–307.
35. Aweda, F. O., and Samson, T. K. 2020. “Modelling the Earth’s Solar Irradiance Across Some Selected Stations in Sub-Sahara Region of Africa.” Iranian (Iranica) Journal of Energy and Environment, 11(3), pp.204–211.
36. Gelaro, R., McCarty, W., Suárez, M. J., Todling, R., Molod, A., Takacs, L., Randles, C. A., Darmenov, A., Bosilovich, M. G., Reichle, R., Wargan, K., Coy, L., Zhao, B. 2017. “The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2).” Journal of Climate, 30(14), pp.5419–5454.