Effect of Flare Stack Radiation on the Mixing Height over Olorunsogo Area of Ogun State, Nigeria

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Mixed layer depth, Solar and flare stack radiations, Atmospheric boundary layer Abstract: Mixing of chemical species released from pollution sources occurs at certain heights in the atmospheric boundary layer of the troposphere. Within this height, mixing of materials occurs due to convective heat transport and mechanical (wind) actions. The mixed layer height can be estimated by analyzing measured meteorological parameters. In this study, the parameterization of meteorological variables based on established mathematical models were used to compute mixed layer height over Olorunsogo in Ogun State, Nigeria. The vertical extent through which pollutants mix occurs was described in a height-temperature profile for both the day time and nocturnal characteristics. The mixing depths were computed for two locations comprising one area with gas flaring operation present and another with no flare stack present. The findings of this study revealed that mixed layer depth for the location without flaring activities, day time ranged between 1200m and 1400m, and at night time as well as early morning ranged between 150m and 400m. In contrast with the location where gas flaring occurred, mixing height ranged between 9280m and 9310m for day time and between 9100m and 9180m for nocturnal period. In addition, it was observed that pollution trapped below the flare during the day, experience rapid vertical motion due to outgoing long wave radiation (OLR) from the surface. While above the flare a vertical motion coupled with dispersion occurs under lapse rate for pollutants, but remained trapped at the inversion layer. At night time, pollutants around the flare advect vertically and experience rapid vertical dispersed motion and after going through the flare are trapped at the inversion layer. Hence most submicron sized particulate matter hardly reaches ground level over areas where gas flaring operations occur except entrainments in wet depositions predominantly through rainfall.

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Periodical:

Edited by:

Prof. A.O. Akii Ibhadode

Pages:

839-847

DOI:

10.4028/www.scientific.net/AMR.367.839

Citation:

G.O. Umosekhaimhe and A.I. Igbafe, "Effect of Flare Stack Radiation on the Mixing Height over Olorunsogo Area of Ogun State, Nigeria", Advanced Materials Research, Vol. 367, pp. 839-847, 2012

Online since:

October 2011

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$35.00

[1] Holtstag, A. A. M. and Van Ulden, A. P., A Simple Scheme for Daytime Estimate of the Surface Fluxes from Routine Weather Data, Journal of Climate and Applied Meteorology 22(4), 1983, 517 – 529.

DOI: 10.1175/1520-0450(1983)022<0517:assfde>2.0.co;2

[2] Igbafe, A. I., Resolving the Atmospheric Sulphur Budget over Elandsfontein area of the Mpumalanga Highveld, PhD thesis, University of Witwatersrand, Johannesburg, 2007, 320p.

[3] Louis, J. F., Nocturnal Boundary Layer Height: Observation by Acoustic Sounders and Prediction in Terms of Surface Layer Parameters, Boundary-Layer Meteorology, 43, 1979, 65 – 77.

DOI: 10.1007/bf00153969

[4] Lakes Environmental Software (2009), AERMET, Meteorological Pre-processor, www. weblakes. com.

[5] Nigerian Gas Company, Operational Manual, (2007).

[6] Marth, L., A Parametric Model of Vertical Eddy Fluxes in the Atmosphere, Boundary-Layer Meteorology, 17, 1981, 102 – 107.

[7] Oke, T. R., Boundary Layer Climates, 2nd Edition, Methuen and Co. Inc, New York, (1978).

[8] Petersen, E.L., Modelling the depth of the stable boundary layer, Boundary-Layer Meteorology, 3, 1993, 19 – 21.

[9] Power Holding Company of Nigeria, Operational Manual, (2007).

[10] Robert, E. S. and Jeff, W. W. (1996), Flare radiation Prediction: A Critical Review, Presentation at the Annual Loss Prevention Symposium of the AIChE, Session 12, Flare Stack and Vapour Control Systems. www. johnzink. com/. /tp_radiation. pdf.

[11] Svensmark, H., Sørensen, J. H., Rasmussen, A, Review and intercomparison of operational methods for the determination of the mixing height, Atmos. Environ, 34, 1996, 1001-1027.

[12] Stefan, B., Analysis and modelling of the Atmospheric Boundary Layer calculations and near ground Sulphur dioxide pollution levels over the Mpumalanga, (2007).

[13] Seinfeld, J. H. and Pandis, S. N., Atmospheric Chemistry and Physics: From air pollution to climate change, Wiley interscience, New York, 1998, 1326p.

[14] Tyson, P. D. and Preston-Whyte, R. A., The Weather and Climate of Southern Africa, 2nd Edition, Oxford University Press, Cape Town, 2000, 396p.

[15] Van Ulden, A. P. and Holtslag, A. A. M., Estimation of the Atmospheric Boundary Layer Parameters for diffusion applications, Journal of Climate and Applied Meteorology, 24, 1985, 1196 -1207.

DOI: 10.1175/1520-0450(1985)024<1196:eoablp>2.0.co;2

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