Abstract
Large-eddy simulations are conducted to investigate the impacts of the scale of chessboard-like heterogeneous surface heating and the background wind on secondary circulations (SCs) in the convective boundary layer (CBL). When the wind blows along the diagonal of the chessboard pattern, the cases with different heterogeneity length scales (λ = 1.2, 2.4, and 4.8 km) and weak background wind (U = 2.5 m s −1) suggest that there exists a threshold for the roll-like SCs, which is satisfied when the heterogeneity length scale is 1.6 times the boundary layer height (λ = 1.6zi). During the CBL development, the SC intensity increases before this threshold is met, whereas it decreases thereafter. The cases with different background wind speeds (U = 2.5, 5.0, and 10.0 m s −1) and relatively large heterogeneity length scale (λ = 4.8 km) show that the SCs are strengthened by larger wind speeds when the heterogeneity length scale is so large that the threshold cannot be met during the CBL development. Another case with wind direction along neither the diagonal nor the side of the chessboard pattern shows that the roll-like SCs can still be triggered, but the roll axes are orientated along the diagonal of the chessboard pattern rather than along the wind direction.
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André, J. C., P. Bougeault, and J. P. Goutorbe, 1990: Regional estimates of heat and evaporation fluxes over non-homogeneous terrain. Examples from the HAPEX-MOBILHY programme. Bound.-Layer Meteor., 50, 77–108, doi: 10.1007/BF00120519.
Avissar, R., and T. Schmidt, 1998: An evaluation of the scale at which ground-surface heat flux patchiness affects the convective boundary layer using largeeddy simulations. J. Atmos. Sci., 55, 2666–2689, doi: 10.1175/1520-0469(1998)055<2666:AEOTSA> 2.0.CO;2.
Chen, F., and R. Avissar, 1994: Impact of landsurface moisture variability on local shallow convective cumulus and precipitation in large-scale models. J. Appl. Meteor. Climatol., 33, 1382–1401, doi: 10.1175/1520-0450(1994)033<1382:IOLSMV> 2.0.CO;2.
Conzemius, R. J., and E. Fedorovich, 2006: Dynamics of sheared convective boundary layer entrainment. Part II: Evaluation of bulk model predictions of entrainment flux. J. Atmos. Sci., 63, 1179–1199, doi: 10.1175/JAS3696.1.
Conzemius, R., and E. Fedorovich, 2007: Bulk models of the sheared convective boundary layer: Evaluation through large eddy simulations. J. Atmos. Sci., 64, 786–807, doi: 10.1175/JAS3870.1.
Courault, D., P. Drobinski, Y. Brunet, et al., 2007: Impact of surface heterogeneity on a buoyancy-driven convective boundary layer in light winds. Bound.-Layer Meteor., 124, 383–403, doi: 10.1007/s10546-007-9172-y.
Deardorff, J. W., 1980: Stratocumulus-capped mixed layers derived from a three-dimensional model. Bound.-Layer Meteor., 18, 495–527, doi: 10.1007/BF001 19502.
Dosio, A., 2005: Turbulent dispersion in the atmospheric convective boundary layer. Ph. D. dissertation, Wageningen University, The Netherlands.
Heus, T., C. C. van Heerwaarden, H. J. J. Jonker, et al., 2010: Formulation of the Dutch atmospheric large-eddy simulation (DALES) and overview of its applications. Geosci. Model Dev., 3, 415–444, doi: 10.5194/gmd-3-415-2010.
Kang, S. L., 2009: Temporal oscillations in the convective boundary layer forced by mesoscale surface heat-flux variations. Bound.-Layer Meteor., 132, 59–81, doi: 10.1007/s10546-009-9391-5.
Kang, S. L., and K. J. Davis, 2008: The effects of mesoscale surface heterogeneity on the fair-weather convective atmospheric boundary layer. J. Atmos. Sci., 65, 3197–3213, doi: 10.1175/2008JAS2390.1.
Kang, S.-L., and D. H. Lenschow, 2014: Temporal evolution of low-level winds induced by two-dimensional mesoscale surface heat-flux heterogeneity. Bound.-Layer Meteor., 151, 501–529, doi: 10.1007/s10546-014-991-8.
Kim, H. J., Y. Noh, and S. Raasch, 2004: Interaction between wind and temperature fields in the planetary boundary layer for a spatially heterogeneous surface heat flux. Bound.-Layer Meteor., 111, 225–246, doi: 10.1023/B:BOUN.0000016471.75325.75.
Kim, S.-W., S.-U. Park, and C.-H. Moeng, 2003: Entrainment processes in the convective boundary layer with varying wind shear. Bound.-Layer Meteor., 108, 221–245, doi: 10.1023/A:1024170229293.
Kim, S.-W., S.-U. Park, D. Pino, et al., 2006: Parameterization of entrainment in a sheared convective boundary layer using a first-order jump model. Bound.-Layer Meteor., 120, 455–475, doi: 10.1007/s10546-006-9067-3.
Letzel, M. O., and S. Raasch, 2003: Large eddy simulation of thermally induced oscillations in the convective boundary layer. J. Atmos. Sci., 60, 2328–2341, doi: 10.1175/1520-0469(2003)060<2328:LESOTI> 2.0.CO;2.
Liu, G., J. N. Sun, and L. Yin, 2011: Turbulence characteristics of the shear-free convective boundary layer driven by heterogeneous surface heating. Bound.-Layer Meteor., 140, 57–71, doi: 10.1007/s10546-011-9591-7.
Liu, Y. Q., and R. Avissar, 1996: Sensitivity of shallow convective precipitation induced by land surface heterogeneities to dynamical and cloud microphysical parameters. J. Geophys. Res., 101, 7477–7497, doi: 10.1029/95JD02167.
Maronga, B., and S. Raasch, 2013: Large-eddy simulations of surface heterogeneity effects on the convective boundary layer during the LITFASS-2003 experiment. Bound.-Layer Meteor., 146, 17–44, doi: 10.1007/s10546-012-9748-z.
Ookouchi, Y., M. Segal, R. C. Kessler, et al., 1984: Evaluation of soil moisture effects on the generation and modification of mesoscale circulations. Mon. Wea. Rev., 112, 2281–2292, doi: 10.1175/1520-0493(1984)112<2281:EOSMEO>2.0.CO;2.
Ouwersloot, H. G., J. V. G. de Arellano, C. C. van Heerwaarden, et al., 2011: On the segregation of chemical species in a clear boundary layer over heterogeneous land surfaces. Atmos. Chem. Phys., 11, 10681–10704, doi: 10.5194/acp-11-10681-2011.
Patton, E. G., P. P. Sullivan, and C.-H. Moeng, 2005: The influence of idealized heterogeneity on wet and dry planetary boundary layers coupled to the land surface. J. Atmos. Sci., 62, 2078–2097, doi: 10.1175/JAS3465.1.
Pino, D., J. V. G. de Arellano, and S.-W. Kim, 2006: Representing sheared convective boundary layer by zeroth-and first-order-jump mixed-layer models: Large-eddy simulation verification. J. Appl. Meteor. Climatol., 45, 1224–1243, doi: 10.1175/JAM2396.1.
Raasch, S., and G. Harbusch, 2001: An analysis of secondary circulations and their effects caused by small-scale surface inhomogeneities using large-eddy simulation. Bound.-Layer Meteor., 101, 31–59, doi: 10.1023/A:1019297504109.
Segal, M., R. Avissar, M. C. McCumber, et al., 1988: Evaluation of vegetation effects on the generation and modification of mesoscale circulations. J. Atmos. Sci., 45, 2268–2292, doi: 10.1175/1520-0469(1988)045<2268:EOVEOT>2.0.CO;2.
Shen, S. H., and M. Y. Leclerc, 1995: How large must surface inhomogeneities be before they influence the convective boundary layer structure? A case study. Quart. J. Roy. Meteor. Soc., 121, 1209–1228, doi: 10.1002/qj.49712152603.
Stull, R. B., 1988: An Introduction to Boundary Layer Meteorology. Springer, Netherlands, 666 pp.
Sühring, M., B. Maronga, F. Herbort, et al., 2014: On the effect of surface heat-flux heterogeneities on the mixed-layer-top entrainment. Bound.-Layer Meteor., 151, 531–556, doi: 10.1007/s10546-014-9913-7.
Sullivan, P. P., and E. G. Patton, 2011: The effect of mesh resolution on convective boundary layer statistics and structures generated by large-eddy simulation. J. Atmos. Sci., 68, 2395–2415, doi: 10.1175/JASD-10-05010.1.
Sun, J. N., and Q. J. Xu, 2009: Parameterization of sheared convective entrainment in the first-order jump model: Evaluation through large-eddy simulation. Bound.-Layer Meteor., 132, 279–288, doi: 10.1007/s10546-009-9394-2.
van Heerwaarden, C. C., and J. V. G. de Arellano, 2008: Relative humidity as an indicator for cloud formation over heterogeneous land surfaces. J. Atmos. Sci., 65, 3263–3277, doi: 10.1175/2008JAS2591.1.
van Heerwaarden, C. C., J. V. G. de Arellano, A. F. Moene, et al., 2009: Interactions between dry-air entrainment, surface evaporation and convective boundary-layer development. Quart. J. Roy. Meteor. Soc., 135, 1277–1291, doi: 10.1002/qj.431.
Wicker, L. J., and W. C. Skamarock, 2002: Time-splitting methods for elastic models using forward time schemes. Mon. Wea. Rev., 130, 2088–2097, doi: 10.11 75/1520-0493(2002)130<2088:TSMFEM>2.0.CO;2.
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The authors thank the anonymous reviewers, whose comments greatly improved the manuscript.
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Supported by the National Natural Science Foundation of China (41475012 and 40975004) and National Key Basic Research and Development (973) Program of China (2010CB428501).
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Shen, L., Sun, J., Yuan, R. et al. Characteristics of secondary circulations in the convective boundary layer over two-dimensional heterogeneous surfaces. J Meteorol Res 30, 944–960 (2016). https://doi.org/10.1007/s13351-016-6016-z
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DOI: https://doi.org/10.1007/s13351-016-6016-z