Abstract
Turbulent flow and reactive pollutant dispersion in the convective boundary layer (CBL) over flat and urban-like surfaces are investigated using a large-eddy simulation model with NO–NO2–O3 chemistry, with the urban-like surface represented by a block array. The CBL over a flat surface with and without ambient flow (FW and FNW cases, respectively) and the CBL over a block array with and without ambient flow (BW and BNW cases, respectively) are simulated. Wind shear in the entrainment zone increases the turbulence intensity and enhances the heat exchange in the entrainment zone. The urban-like surface induces greater wind shear in the entrainment zone, thus the largest turbulence intensity and heat exchange are found in the BW case. High NO concentration appears in updraft regions, whereas high O3 concentration appears in downdraft regions. The segregation of NO and O3 reduces the O3 decomposition in the CBL. The magnitude of the vertical gradients of NO, NO2, and O3 concentrations in the entrainment zone is smallest in the BW case, indicating that the largest reactive pollutant exchange occurs in the BW case. It seems that the greater wind shear in the entrainment zone induced by the urban-like surface also enhances the reactive pollutant exchange in the entrainment zone. The magnitude of the O3 production rate in the entrainment zone is large due to the mixing of mixed-layer air with air in the entrainment zone, especially around updraft regions. Since the segregation of NO and O3 interrupts the O3 decomposition, the turbulent component of the O3 production rate is generally positive in the CBL. The reduction of the O3 decomposition due to the segregation in the entrainment zone is smallest in the BW case. The effects of segregation on the chemical reactions are reduced due to the strengthened turbulent motions in the BW case.
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References
Arakawa A, Lamb VR (1977) Computational design of the basic dynamical processes of the UCLA general circulation model. Methods Comput Phys 17:173–265
Baik JJ, Kang YS, Kim JJ (2007) Modeling reactive pollutant dispersion in an urban street canyon. Atmos Environ 41:934–949
Baker J, Walker HL, Cai X (2004) A study of the dispersion and transport of reactive pollutants in and above street canyons—a large eddy simulation. Atmos Environ 38:6883–6892
Chung TNH, Liu CH (2012) Large-eddy simulation of reactive pollutant dispersion for the spatial instability of photostationary state over idealised 2D urban street canyons. Int J Environ Pollut 50:2–6
Conzemius RJ, Fedorovich E (2006) Dynamics of sheared convective boundary layer entrainment. Part I: methodological background and large-eddy simulations. J Atmos Sci 63:1151–1178
Deardorff JW (1970) Convective velocity and temperature scales for the unstable planetary boundary layer and Rayleigh convection. J Atmos Sci 27:1211–1213
Deardorff JW (1980) Stratocumulus-capped mixed layers derived from a three-dimensional model. Boundary-Layer Meteorol 18:495–527
Fedorovich E (2004) Dispersion of passive tracer in the atmospheric convective boundary layer with wind shears: a review of laboratory and numerical model studies. Meteorol Atmos Phys 87:3–21
Halios CH, Barlow JF (2018) Observations of the morning development of the urban boundary layer over London, UK, taken during the ACTUAL project. Boundary-Layer Meteorol 166:395–422
Han BS, Baik JJ, Kwak KH, Park SB (2018) Large-eddy simulation of reactive pollutant exchange in and above a street canyon. Atmos Environ 187:381–389
Henn DS, Sykes RI (1992) Large-eddy simulation of dispersion in the convective boundary layer. Atmos Environ 26:3145–3159
Khanna S, Brasseur JG (1998) Three-dimensional buoyancy- and shear-induced local structure of the atmospheric boundary layer. J Atmos Sci 55:710–743
Kim SW, Park SU (2003) Coherent structures near the surface in a strongly sheared convective boundary layer generated by large-eddy simulation. Boundary-Layer Meteorol 106:35–60
Kim SW, Park SU, Moeng CH (2003) Entrainment processes in the convective boundary layer with varying wind shear. Boundary-Layer Meteorol 108:221–245
Krol MC, Molemaker MJ, Vilà-Guerau de Arellano J (2000) Effects of turbulence and heterogeneous emissions on photochemically active species in the convective boundary layer. J Geophys Res Atmos 105:6871–6884
Kwak KH, Baik JJ, Ryu YH, Lee SH (2015) Urban air quality simulation in a high-rise building area using a CFD model coupled with mesoscale meteorological and chemistry-transport models. Atmos Environ 100:167–177
Letzel MO, Krane M, Raasch S (2008) High resolution urban large-eddy simulation studies from street canyon to neighbourhood scale. Atmos Environ 42:8770–8784
Maronga B, Gryschka M, Heinze R, Hoffmann F, Kanani-Sühring F, Keck M, Ketelsen K, Letzel MO, Sühring M, Raasch S (2015) The Parallelized Large-Eddy Simulation Model (PALM) version 4.0 for atmospheric and oceanic flows: model formulation, recent developments, and future perspectives. Geosci Model Dev 8:2515–2551
Mason PJ (1989) Large-eddy simulation of the convective atmospheric boundary layer. J Atmos Sci 46:1492–1516
Mavroidis I, Ilia M (2012) Trends of NOx, NO2 and O3 concentrations at three different types of air quality monitoring stations in Athens, Greece. Atmos Environ 63:135–147
Miao S, Chen F (2008) Formation of horizontal convective rolls in urban areas. Atmos Res 89:298–304
Moeng CH, Sullivan PP (1994) A comparison of shear- and buoyancy-driven planetary boundary layer flows. J Atmos Sci 51:999–1022
Moeng CH, Wyngaard J (1984) Statistics of conservative scalars in the convective boundary layer. J Atmos Sci 41:3161–3169
Park SB, Baik JJ (2014) Large-eddy simulations of convective boundary layers over flat and urbanlike surfaces. J Atmos Sci 71:1880–1892
Petersen AC, Beets C, Krol MC (1996) Parametrization of segregation effects due to convective boundary-layer mixing in atmospheric chemistry models. Phys Chem Earth 21:445–450
Petersen AC, Beets C, van Dop H, Duynkerke PG, Siebesma AP (1999) Mass-flux characteristics of reactive scalars in the convective boundary layer. J Atmos Sci 56:37–56
Schmidt H, Schumann U (1989) Coherent structure of the convective boundary layer derived from large-eddy simulations. J Fluid Mech 200:511–562
Schumann U (1989) Large-eddy simulation of turbulent diffusion with chemical reactions in the convective boundary layer. Atmos Environ 23:1713–1727
Sorbjan Z (2005) Statistics of scalar fields in the atmospheric boundary layer based on large-eddy simulations. Part I: free convection. Boundary-Layer Meteorol 116:467–486
Sorbjan Z (2006) Statistics of scalar fields in the atmospheric boundary layer based on large-eddy simulations. Part II: forced convection. Boundary-Layer Meteorol 119:57–79
Sühring M, Maronga B, Herbort F, Raasch S (2014) On the effect of surface heat-flux heterogeneities on the mixed-layer-top entrainment. Boundary-Layer Meteorol 151:531–556
Sykes RI, Henn DS (1989) Large-eddy simulation of turbulent sheared convection. J Atmos Sci 46:1106–1118
Vilà-Guerau de Arellano J, Dosio A, Vinuesa JF, Holtslag AAM, Galmarini S (2004) The dispersion of chemically reactive species in the atmospheric boundary layer. Meteorol Atmos Phys 87:23–38
Wyngaard JC, Brost R (1984) Top-down and bottom-up diffusion of a scalar in the convective boundary layer. J Atmos Sci 41:102–112
Zhang Y, Wang Y, Chen G, Smeltzer C, Crawford J, Olson J, Szykman J, Weinheimer AJ, Knapp DJ, Montzka DD, Wisthaler A, Mikoviny T, Fried A, Diskin G (2016) Large vertical gradient of reactive nitrogen oxides in the boundary layer: modeling analysis of DISCOVER-AQ 2011 observations. J Geophys Res Atmos 121:1922–1934
Zhong J, Cai XM, Bloss WJ (2015) Modelling segregation effects of heterogeneous emissions on ozone levels in idealised urban street canyons: using photochemical box models. Environ Pollut 188:132–143
Zhong J, Cai XM, Bloss WJ (2016) Coupling dynamics and chemistry in the air pollution modelling of street canyons: a review. Environ Pollut 214:690–704
Acknowledgements
The authors are grateful to three anonymous reviewers for providing valuable comments on this work. This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (No. 2016R1A2B2013549).
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Han, BS., Baik, JJ., Park, SB. et al. Large-Eddy Simulations of Reactive Pollutant Dispersion in the Convective Boundary Layer over Flat and Urban-Like Surfaces. Boundary-Layer Meteorol 172, 271–289 (2019). https://doi.org/10.1007/s10546-019-00447-2
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DOI: https://doi.org/10.1007/s10546-019-00447-2