The Nigerian Micrometeorological Experiment (NIMEX-1): an overview

Jegede, OO; Maunder, Michael; Okogbue, Emmanuel Chilekwu; Foken, Thomas; Balogun, EE; Adedokun, J. A.; Oladiran, E. O.; Omotosho, JA; Balogun, AA; Oladosu, OR; Sunmonu, L A; Ayoola, MA; Aregbesola, TO; Ogolo, EO; Nymphas, EF; Adeniyi, M. O.; Olatona, GI; Ladipo, KO; Ohamobi, SI; Gbobaniyi, EO; Akinlade, GO

doi:10.4314/ijs.v6i2.32147

Cited by 15 publications

(17 citation statements)

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“…On the other hand, the day with the lowest wind velocities (07/06/2003) also has a reduced residual. This agrees with findings by Jegede et al (2004) describing an experiment in the tropics with a strong radiation forcing, where the energy balance was closed in most of the cases. For this experiment, the same data calculation software was used as for LITFASS-2003.…”

Section: Discussionsupporting

confidence: 92%

Some aspects of the energy balance closure problem

et al. 2006

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Abstract. After briefly discussing several reasons for the energy balance closure problem in the surface layer, the paper focuses on the influence of the low frequency part of the turbulence spectrum on the residual. Changes in the turbulent fluxes in this part of the turbulence spectrum were found to have a significant influence on the changes of the residual. Using the ogive method, it was found that the eddy-covariance method underestimates turbulent fluxes in the case of ogives converging for measuring times longer than the typical averaging interval of 30 min. Additionally, the eddy-covariance method underestimates turbulent fluxes for maximal ogive functions within the averaging interval, both mainly due to advection and non-steady state conditions. This has a considerable influence on the use of the eddy-covariance method.

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Section: Discussionsupporting

confidence: 92%

Some aspects of the energy balance closure problem

et al. 2006

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“…Analysis of all input variables can be obtained from Jegede et al [10]. However, other needed parameters required for estimation of sensible and latent heat fluxes were parameterized from these meteorological variables.…”

Section: Resultsmentioning

confidence: 99%

“…The word ratio here compares sensible heat flux to latent heat flux. This is defined as [5,6,10] Sensible heat flux Latent heat flux…”

Section: Theoretical Methods Of Estimating Convective Heat Fluxes Bowmentioning

confidence: 99%

Parameterization of Convective Heat Fluxes over Ile-Ife Using Bowen Ratio, Aerodynamic Gradient and Aerodynamic with Resistance Techniques

Adeyemi¹,

Ogolo²,

Ajakaiye³

2017

Appl Sci Res Rev

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on surface convective heat fluxes. Convective heat fluxes are the responses of the forcing net radiation flux received at the land-air boundary. Jegede, Balogun, and Ohmura are the earlier researchers who attempted the estimation of convective heat fluxes using indirect flux-gradient and Bowen ratio methods [4][5][6][7]. In 2012, Omokugbe et al. investigated the portioning of the net radiation flux and the surface energy fluxes using the Eddy Covariance method and presented that the midnight and the early morning hours of the days recorded negative values for the net radiation but increased at 7:30 h to peak values ranging from 317 W/m 2 to 586 W/m 2 [8]. As good as direct measurement of heat fluxes has been, it is important to stress that the cost of acquiring, installing and maintaining stations for direct measurement (using eddy covariance method) is beyond IntroductionThe role of convective heat fluxes in the tropospheric processes cannot be overemphasized. Land surface heat fluxes are essential components of the water and energy cycles and govern the interactions between the Earth surface and the atmosphere. The results from each of the techniques were correlated with the measured heat fluxes in order to decide the best theoretical approach for the estimation of fluxes over the region of study. BR and AG compared moderately with the measured fluxes. BR scheme overestimated latent heat flux but underestimated sensible heat flux; AG technique slightly underestimated sensible heat flux but strongly underestimated latent heat fluxes with only few days of overestimation of sensible heat flux. AR, on the other hand, underestimated both latent and sensible heat fluxes. The obtained closure for AG proved much closer to the closure obtained from the direct measurement, BR has a better theoretical closure while AR failed as a whole. The trends as well as statistical analysis proved that AG performed best for sensible heat flux while BR presented good results for both latent heat flux and energy closure.

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“…The ground surface of the site is flat and homogenous. The soil is loamy sand and it is at its permanent wilting condition at the beginning of the experiment (Jegede et al 2004;Mauder et al 2006). The maximum and minimum air temperatures during the period of the experiment were 46.33 and 20.04 °C, respectively and the mean annual rainfall amount is 1225 mm (Otunla and Oladiran 2013).…”

Section: Experimental Sitesmentioning

confidence: 99%

“…Nigeria Micrometeorological Experiment (NIMEX) (Jegede et al 2004) was conducted at Ile Ife (Latitude 7°33′N and longitude 4°33′E) in Nigeria during the transition period from dry to wet season (Fig. 1).…”

Section: Experimental Sitesmentioning

confidence: 99%