DETERMINING VERTICAL WIND SPEED PROFILE IN THE ATMOSPHERIC LIMIT LAYER ON THE OUAHIGOUYA SITE IN BURKINA FASO

The properties of the vertical profile of the wind speed on a monthly and annual scale at the Ouahigouya site belonging to the Sahelian climatic zone in Burkina Faso were explored in this study. To do this, wind speed and temperature data at 10 m above ground and NASA satellite data at an altitude of 50 m in the atmospheric boundary layer were used over a period of ten years. From the theory of Monin-Obukhov, the logarithmic law and the power law made it possible to develop the variation of wind speed with altitude taking into account the conditions of atmospheric stability. According to statistical performance indicators, it has been observed that the vertical profile of the wind speed adjusted according to the power law and the log-linear law corresponds to the measurements. Regarding the state of stability of the atmosphere, we note that it is generally unstable from 10:00 a.m. to 6:00 p.m. and stable during other times of the day. The annual average wind shear coefficients during the convective and night time diurnal cycle are evaluated at 0.67 and 0.7, respectively. From the power law, the values of the shear coefficients, the average vertical profile on a monthly and annual scale of the wind was obtained by extrapolation of the wind data measured at 10 m from the ground. This study is the first of its kind in this area. To assess the wind resource available on the Ouahigouya site, investors can directly use the vertical wind profile based on the power law for an altitude between 10 and 50 m.