Investigation of surface energy budget over a humid tropical site at Ile-Ife, Nigeria: A comparison of eddy covariance and Bowen ratio methods

Abstract

Research grade-data for estimating surface energy budget is still scarce for the humid tropical West African sub-region despite its vital importance in development and validation of the numerical models both at regional and global scales. The present paper examines the surface energy budget data collected over a humid tropical site at Ile-Ife, Nigeria (7.55^oN, 4.56^oE, 296 m) from eddy covariance (EC) and Bowen ratio (BR) methods during February/March and July 2007. The two periods represent transition from dry to wet and entirely wet season, respectively. The differences in the partitioning of the fluxes by both methods were examined. The mean closures were 92.21 and 80.72% for February/March and July, respectively. The EC and BR were found to partition fluxes differently. The BR estimation of sensible heat flux (H_S) was consistently higher than EC while the BR estimation of latent heat flux (H_LE) was higher in the morning hours before sunrise. At sunrise, however, the EC estimation H_LE was higher than that of BR. The difference in net radiation (R_N), ground heat flux (H_G), and soil moisture by both methods were also reported.