Abstract

Author:
D.O. Akpootu., A.K. Isah., A. Yusuf., M. A. Aliyu., G. Bello, T.A. Kola

Doi: 10.26480/efcc.02.2024.76.80

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Within the solar radiation spectrum, photosynthetically active radiation (PAR) is found between 400 and 700 nm. Modelling ecosystems and conducting research on climate change require an understanding of the incident PAR at the earth’s surface. In this work, PAR was estimated and investigated for Owerri (latitude 5.48°N, longitude 7.00°E, and 91.0 m), which is located in the coastal region of Nigeria. The measured monthly average daily global solar radiation, relative humidity, wind speed, minimum and maximum temperature dataset were used. The National Aeronautics and Space Administration (NASA) archives provided the meteorological characteristics used in this study during a thirty-eight-year period (1984–2021). In order to determine the models’ accuracy, newly developed temperature PAR-based models were put to the test using statistical indicators such as the coefficient of determination (R2), mean bias error (MBE), root mean square error (RMSE), mean percentage error (MPE), t-test, and index of agreement (IA). Based on the findings, PAR, or photosynthetically active radiation, is higher in the dry season and lower in the rainy period, having R2, MBE, RMSE, MPE, t-test, and IA values of 83.5%, -0.0356 MJm-2day-1, 0.3515 MJm-2day-1, 0.3246 %, 0.3376, and 95.4690 %, respectively, the model that relates PAR with temperature difference, mean temperature, and temperature ratio was found to be the most appropriate for estimating PAR for Owerri based on the models developed for the region.