One (1) hourly data of variables such as 10 m wind speed (u10), sea surface temperature (SST) and 2 m air temperature obtained from ERA5 Reanalysis over a 84 year (1940-2023) period were used to statistically evaluate the performance of thirteen (13) proposed predictive equations and some existing equations to predict wind friction velocity (u*) at omu creek, Mahin in Ilaje Local Government Area, Ondo State, Southwestern Nigeria. Results showed that Equation (9), u* = a + b(u) + c(Tr) + d(Tm) performed best in predicting u*. The frequency of the wind flow characteristics has been investigated in the location. Results showed that the transitional flow prevailed in the location. Also, investigation on the temporal trends in the wind flow characteristics showed that transition flow exhibited an inclining and the strongest trend of 0.0556% yr−1 throughout the study period. The aerodynamically smooth flow and the fully rough flow exhibited declining trends of −0.0495% yr−1 and −0.006% yr−1 respectively. Lastly, Equation (9) is tested in near and far waters. Findings showed that the formula performed best in Bijimi. This is attributed to the nearness of the location to omu creek than the rest locations. The formula showed the worst performance in Bakingil, Cameroon.
Parameterizing the Wind Friction Velocity and Characterization of Flow Regimes at Omu Creek, Mahin in Ilaje Local Government Area, Ondo State, Southwestern Nigeria
Lateef Adesola Afolabi;Pasquale Contestabile
2024
Abstract
One (1) hourly data of variables such as 10 m wind speed (u10), sea surface temperature (SST) and 2 m air temperature obtained from ERA5 Reanalysis over a 84 year (1940-2023) period were used to statistically evaluate the performance of thirteen (13) proposed predictive equations and some existing equations to predict wind friction velocity (u*) at omu creek, Mahin in Ilaje Local Government Area, Ondo State, Southwestern Nigeria. Results showed that Equation (9), u* = a + b(u) + c(Tr) + d(Tm) performed best in predicting u*. The frequency of the wind flow characteristics has been investigated in the location. Results showed that the transitional flow prevailed in the location. Also, investigation on the temporal trends in the wind flow characteristics showed that transition flow exhibited an inclining and the strongest trend of 0.0556% yr−1 throughout the study period. The aerodynamically smooth flow and the fully rough flow exhibited declining trends of −0.0495% yr−1 and −0.006% yr−1 respectively. Lastly, Equation (9) is tested in near and far waters. Findings showed that the formula performed best in Bijimi. This is attributed to the nearness of the location to omu creek than the rest locations. The formula showed the worst performance in Bakingil, Cameroon.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.