ANALYSING THE IMPACT OF SOIL PARAMETERS ON THE SENSIBLE HEAT FLUX USING SIMULATED TEMPERATURE CURVE MODEL

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1 International Journal of Physics and Research (IJPR) ISSN -3 Vol., Issue Dec 1 1- TJPRC Pvt. Ltd., ANALYSING THE IMPACT OF SOIL PARAMETERS ON THE SENSIBLE HEAT FLUX USING SIMULATED TEMPERATURE CURVE MODEL ABSTRACT UNO E. UNO & MOSES E. EMETERE Department of Physics, Federal University of Technology of Minna, Nigeria Researchers have shown that sensible heat flux play important role in agriculture, health and environment. Temperature deviation curve model was used to investigate the impact of soil parameters on the sensible heat flux. The fractional relationship between the sensible heat flux and soil heat flux were worked out. The results showed that the original equation of Sellers et al.,(199) need to be properly reviewed to enable an holistic calculation of the earth s net radiation. KEYWORDS: Sensible Heat Flux, Soil Heat Flux, Soil Damp Depth, Soil Density Ratio And Earth s Net Radiation INTRODUCTION The importance of sensible heat flux cannot be overemphasized. It can be used to model evaporation within various region of the world. Sensible heat flux is the rate of heat loss to the air by convection and conduction, due to a temperature difference. Albertson et al.,(199) worked on the use of atmospheric similarity theory to analyze the impact of air temperature on the sensible heat flux. They concluded that the air temperature provides a better a parameter for measuring sensible heat flux than wind speed or evaporation as researched by Guymon et al.,(199). This sensible heat flux was proven to be the same as the soil heat flux on a well-watered and full-vegetation-covered surface (Kustas et al., 199; Cheng et al., 9). In the contrary, Angelina et al.() and Sellers et al.,(199) gave a mathematical equation showing the net radiation energy and its component- sensible heat flux, latent heat flux and soil heat flux. They proved that soil heat flux is negligible because it contributes less than 1% of the net radiation energy. Other researcher (Idso et al., 197) reported that the soil heat flux contributes up to % of the net radiation. The (Pan et al., 197). The temperature curve model has been used in different aspect of soil science i.e. to determine the susceptibility of Abuja metropolis to soil compaction (Uno et al., 1a); determine the annual amplitude of the surface soil temperatures of the same region (Uno et al., 1a); estimate soil heat flux from both short and long-term remotely sensed surface temperature (Uno et al., 1b); prediction and monitoring earthquakes (Emetere, 1). In this paper, the importance of temperature deviation curve was discussed with respect to sensible heat flux to primarily determine the impact of soil properties on sensible flux density. Furthermore, this paper (upon further research) may be used to discuss atmospheric heat dynamics and the health hazards from atmospheric radiations. BACKGROUND THEORY The temperature deviation curve model introduced by Uno et al.,(1) is given by sensible heat flux affects the soil water content over a specific region. Likewise, the soil water content controls the soil heat flux and evapotranspiration because the soil heat conductivity and the soil heat capacity are strong functions of soil water content [1]

2 Uno E. Uno & Moses E.Emetere = soil particle density which is a approximately.gcm -3 by Gupta et al.,. (11), = soil bulk density. T= temperature deviation, A is the annual amplitude of the surface soil temperature. The soil heat density given by Cheng et al(9) was given as [] where G(z,t) = instantaneous surface soil heat flux density (W m - ); T = the amplitude of the surface temperature ( C) wave (Tmax - Tmin)/, t = time of day (sec); = the soil thermal conductivity (W m -1 K -1 ); C = the volumetric heat capacity (J m -3 K -1 ) ω = frequency, D=thermal diffusivity, Z = soil depth, d is the damping depth (m) of annual fluctuation and t is the time lag. Uno et al(1) have proven that. Unlike the net radiation energy, Idso et al.,(197), we assumed that the latent heat flux was negligible which led to the following equations (i.e equation 3-7) When the soil heat flux is %, the sensible heat flux is [3] When the soil heat flux is %, the sensible heat flux is [] When the soil heat flux is 3%, the sensible heat flux is [] When the soil heat flux is %, the sensible heat flux is [] When the soil heat flux is %, the sensible heat flux is [7] The METRIC, developed by Allen et al.,() gave the relationship between sensible heat flux and the temperature difference as [] Where is the sensible heat flux density, is air density, is air specific heat, dt (K) is the temperature difference (T 1 T ) between two heights (z 1 and z ), and r ah is the aerodynamic resistance to heat transport (s/m) between z 1 and z. On the assumption that, therefore, equation [] develops into [9]

3 Analysing the Impact of Soil Parameters on the Sensible Heat Flux Using Simulated Temperature Curve Model 3 SIMULATION OF DERIVATIONS sensible heat flux when the soil heat flux is % of the net radiation at depth cm sensible heat flux when the soil heat flux is % of the net radiation at depth cm sensible heat flux when the soil heat flux is % of the net radiation at depth cm sensible heat flux when the soil heat flux is % of the net radiation at depth cm Figure 1: The Sensible Heat Flux When the Soil Heat Flux Density is % of the Net Radiation at Different Depth The simulations led to the following equation as Shown in the Figure Above where Adopting the equations of Albertson et al(199) on relation between the angular frequency, thermal diffusivity and damping depth and Equation() was derived [] the heat dispersion time and damp depth-derivation of eqn[] t-to D B Figure : Analysis of the Time and Damping Depth Under a Constant β

4 Uno E. Uno & Moses E.Emetere t-t o Figure 3: A Graph of time Lag Against β Gotten from in Figure 1 β t-t o Figure : A Graph of time Lag Against Damping Depth Gotten from in Figure 1 D sensible heat flux when the soil heat flux is % of the net radiation at depth cm sensible heat flux when the soil heat flux is % of the net radiation at depth cm sensible heat flux when the soil heat flux is % of the net radiation at depth cm sensible heat flux when the soil heat flux is % of the net radiation at depth cm Figure : The Sensible Heat Flux When the Soil Heat Flux Density is % of the net Radiation at Different Depth as Shown in the Figure Above

5 Analysing the Impact of Soil Parameters on the Sensible Heat Flux Using Simulated Temperature Curve Model Figure : The Effects of Density Ratio on the Sensible Heat Flux Figure 7: The Effects of Annual Amplitude of the Surface Soil Temperatures on the Sensible Heat Flux RESULTS AND DISCUSSIONS The results of the derivations (equation [3]-[7]) shows that the increase in the soil heat flux in percentage in the net radiation has an approximate progression on the sensible heat flux which can be mathematically written as This can be simply written [11]

6 Uno E. Uno & Moses E.Emetere This mathematical equation can be used to estimate the fractional effect of the soil heat flux on the sensible heat flux in any area. The unique feature of equation [3]-[7] is how it relates the impact of soil properties on sensible heat flux (on the background of fractional equivalent term discuss in equation[11]). Figure 1& was intended to investigate the impact of soil properties on the sensible heat flux. It was discovered that the increase in damping depth or soil depth actually decreases the effect on the sensible heat flux. Uno et al.(1b) had earlier proved that an increase in the soil depth and density increased the soil heat flux. This results corresponds with researchers (Allen et al., 7; Olejnik et al.,1;uno et al.,1b) because an increase in the soil heat flux suggest decrease in the sensible heat flux in the net radiation. More so, the sensible heat flux was maximum at = for all conditions progression of soil/damp depth ratio (see figure 1). It simply translate that provided the principle of conservation of energy is obeyed, the maximum angle (Φ) require for the fractional conversion of soil heat flux to sensible heat flux is.the formation of figure1 sparked-up another investigation on the heat dynamics within and at the surface of the earth which was expressed in equation [] and Figure &3. The flow of heat within and on the surface is dependent on a parabolic factor which may be calculated upon experimental research. The relationship between the time lag and the thermal diffusivity (figure ) reveals that even at zero time lag, the heat diffusivity is latent (.3) which means that more mathematical terms ought to be added to Sellers et al.,(199) equation of net radiation to give accurate account of the heat transformations. Figure explains that the soil and damp depth ratio (z/d) has further diminishing effects on the sensible heat flux even when the soil heat flux is increased to % of the net radiation.the Equation[9] was originally derived to investigate the effects of annual amplitude of the surface soil temperatures and soil density ratio on the magnitude of the sensible heat flux. Both parameter showed a Boltzmann distribution (figure & 7) which is interpreted that the sensible heat flux at cold. Also, it revealed that the radiation from the earth (at certain critical condition as shown in figure & 7) may cause serious health hazard when the soil heat flux is about % of the net radiation. CONCLUSIONS The sensible heat flux related the soil heat flux through the fractional mathematical term. Mathematically, soil parameters had impact on the sensible heat flux which by extension can be used to analyze the effects of global warming on any region of the earth. The net radiation equation given by Sellers et al.,(199) need to be properly reviewed to enable an holistic calculation of the earth s net radiation. Soil parameters should be incorporated to the (theoretical and experimental) methods of determining the sensible heat flux over any region. APPRECIATIONS This work is self-funded. I appreciate Mrs. Jennifer Emetere for editing the script. I appreciate the Head of Physics Department of the above named institution REFERENCES 1) Angelina Mikova and Alexandrova Petra () Investigation of soil heat flux in Vertic Luvisol.

7 Analysing the Impact of Soil Parameters on the Sensible Heat Flux Using Simulated Temperature Curve Model 7 ) Sellers, P. J., Randall, D. A., Collatz, G. J., Berry, J. A., Field, C. B., Dazlich, D. A., Zhang, C., Collelo, G. D., and Bounoua, L. (199)A revised land surface parameterization (SiB) for atmospheric GCMs, Part I: Model formulation, J. Climate, 9, 7 7, 3) John D. Albertson, Marc B. Partange, Gabriel G. Katul, Chia-Ren Chu, and Han Stricker.199. Sensible heat flux from arid regions:a simple flux variance method. Water Resources Research, 31(): ) Cheng-I Hsieh & Cheng-Wei Huang & Ger Kiely. 9. Long-term estimation of soil heat flux by single layer soil temperature.int J Biometeorol 3: ) Kustas WP, Daughtry C.S.T.199. Estimation of the soil heat flux/net radiation ratio from spectral data. Agric For Meteorol 9: 3 ) Uno E Uno, Moses E Emetere, Adelabu J.S.A. 1. Parametric Investigation Of Soil Susceptibility To Compaction Using Temperature Deviation Curves. Journal of Civil Engineering and Architecture Vol. 1,issue pp.1-7) Uno E Uno, Moses E Emetere, Eneh C Daniel.(1). Simulated Analysis Of Soil Heat Flux Using Temperature Deviation Curve Model. Science Journal of Physics. Vol. 1, Issue,pp 1-9 ) Moses E. Emetere (1) Monitoring And Prediction Of Earthquakes Using Simulated Temperature Deviation Curve Model.International Journal for applied information system 9) Allen, R.G, Trezza, R, and Tasumi, M.. Analytical integrated functions for daily solar radiation on slopes. Agric For Meteorol 139: -73. ) Olejnik J., Eulenstein F., Kêdziora A., and Werner A.1. Evaluation of water balance model using data for bare soil and crop surfaces in middle Europe. Agric. For. Meteorol., /, -11

Simulated Analysis of Soil Heat Flux Using Temperature Deviation Curve Model. G(0,t) =

Simulated Analysis of Soil Heat Flux Using Temperature Deviation Curve Model. G(0,t) = Science Journal of Physics ISSN: 2276-6367 http://www.sjpub.org/sjp.html Author(s) 2012. CC Attribution 3.0 License. Research Article Published By Science Journal Publication International Open Access