Abstract
A theoretical approach suggests that the surface heterogeneity on a scale of tens of kilometres can generate mesoscale motions that are not in a quasi-stationary state. The starting point of the theoretical approach is the equations of horizontal velocity and potential temperature that are low-pass filtered with a mesoscale cut-off wavelength. The transition of the generated mesoscale motions from a quasi-stationary state to a non-stationary state occurs when horizontal advection is strong enough to level out the potential temperature gradient on the surface heterogeneity scale. Large-eddy simulations (LES) suggest that the convective boundary layer (CBL) changes to a non-stationary state when forced by a surface heat-flux variation of amplitude of 100W m−2 or higher and a wavelength of the order of 10 km. Spectral analysis of the LES reveals that when the mesoscale motions are in a quasi-stationary state, the energy provided by the surface heat-flux variation remains in organized mesoscale motions on the scale of the surface variation itself. However, in a non-stationary state, the energy cascades to smaller scales, with the cascade extending down into the turbulence scale when the wavelength of the surface heat-flux variation is on a scale smaller than 100 times the CBL height. The energy transfer from the generated mesoscale motions to the CBL turbulence results in the absence of a spectral gap between the two scales. The absence of an obvious spectral gap between the generated mesoscale motions and the turbulence raises questions about the applicability of mesoscale models for studies on the effect of high-amplitude surface heterogeneity on a scale of tens of kilometres.
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Avissar R, Schmidt T (1998) An evaluation of the scale at which ground-surface heat flux patchiness affects the convective boundary layer using a large-eddy simulation model. J Atmos Sci 55: 2666–2689. doi:10.1175/1520-0469(1998)055<2666:AEOTSA>2.0.CO;2
Baldi M, Dalu GA, Pielke RA Sr (2008) Vertical velocities and available potential energy generated by landscape variability—theory. J Appl Meteorol Climatol 47: 397–410. doi:10.1175/2007JAMC1539.1
Bannon PR, Chagnon JM, James RP (2006) Mass conservation and the anelastic approximation. Mon Weather Rev 134: 2989–3005. doi:10.1175/MWR3228.1
Bryan GH, Fritsch JM (2002) A benchmark simulation for moist nonhydrostatic numerical models. Mon Weather Rev 130: 2917–2928. doi:10.1175/1520-0493(2002)130<2917:ABSFMN>2.0.CO;2
Bryan GH, Rotunno R (2008) Gravity currents in a deep anelastic atmosphere. J Atmos Sci 65: 536–556. doi:10.1175/2007JAS2443.1
Bryan GH, Wyngaard JC, Fritsch JM (2003) Resolution requirements for the simulation of deep moist convection. Mon Weather Rev 131: 2394–2416. doi:10.1175/1520-0493(2003)131<2394:RRFTSO>2.0.CO;2
Chen F, Avissar R (1994) The impact of land-surface wetness heterogeneity on mesoscale heat fluxes. J Appl Meteorol 33: 1323–1340. doi:10.1175/1520-0450(1994)033<1323:TIOLSW>2.0.CO;2
Dalu GA, Pielke RA (1993) Vertical heat fluxes generated by mesoscale atmospheric flow induced by thermal inhomogeneities in the PBL. J Atmos Sci 33: 919–926. doi:10.1175/1520-0469(1993)050<0919:VHFGBM>2.0.CO;2
Dalu GA, Pielke RA, Avissar R, Kallos G, Baldi M, Guerrini A (1991) Linear impact of thermal inhomogeneities on mesoscale atmospheric flow with zero synoptic wind. Ann Geophys 9: 641–647
Dalu GA, Pielke RA, Baldi M, Zeng X (1996) Heat and momentum fluxes induced by thermal inhomogeneities with and without large-scale flow. J Atmos Sci 53: 3286–3302. doi:10.1175/1520-0469(1996)053<3286:HAMFIB>2.0.CO;2
Dalu GA, Pielke RA Sr, Vidale PL, Baldi M (2000) Heat transport and weakening of atmospheric stability induced by mesoscale flows. J Geophys Res 105: 9349–9363. doi:10.1029/1999JD901064
Deardorff JW (1970) Convective velocity and temperature scales for the unstable planetary boundary layer and for Rayleigh convection. J Atmos Sci 27: 1211–1213. doi:10.1175/1520-0469(1970)027<1211:CVATSF>2.0.CO;2
Durran DR, Klemp JB (1983) A compressible model for the simulation of moist mountain waves. Mon Weather Rev 111: 2341–2361. doi:10.1175/1520-0493(1983)111<2341:ACMFTS>2.0.CO;2
Esau IN (2007) Amplification of turbulent exchange over wide Arctic leads: large-eddy simulation study. J Geophys Res 112: D08109. doi:10.1029/2006JD007225
Finkele K, Hacker JM, Kraus H, Byron-Scott RAD (1994) A complete sea-breeze circulation cell derived from aircraft observations. Boundary-Layer Meteorol 73: 299–317. doi:10.1007/BF00711261
Hadfield MG, Cotton WR, Pielke RA (1991) Large-eddy simulations of thermally forced circulations in the convective boundary layer. Part I: a small-scale circulation with zero wind. Boundary-Layer Meteorol 57: 79–114. doi:10.1007/BF00119714
Hadfield MG, Cotton WR, Pielke RA (1992) Large-eddy simulations of thermally forced circulations in the convective boundary layer. Part II: the effect of changes in wavelength and wind speed. Boundary-Layer Meteorol 58: 307–327. doi:10.1007/BF00120235
Kaimal J, Wyngaard J, Haugen D, Cote O, Izumi Y, Caughey S, Readings C (1976) Turbulence structure in the convective boundary layer. J Atmos Sci 33: 2152–2169. doi:10.1175/1520-0469(1976)033<2152:TSITCB>2.0.CO;2
Kang S-L, Davis K (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, Davis KJ, LeMone M (2007) Observations of the ABL structures over a heterogeneous land surface during IHOP_2002. J Hydrometeorol 8: 221–244. doi:10.1175/JHM567.1
Kimmel SJ, Wyngaard JC, Otte MJ (2002) “Log-Chipper” turbulence in the convective boundary layer. J Atmos Sci 59: 1124–1134. doi:10.1175/1520-0469(2002)059<1124:LCTITC>2.0.CO;2
Lele SK (1992) Compact finite difference schemes with spectral-like resolution. J Comput Phys 103: 16–42. doi:10.1016/0021-9991(92)90324-R
LeMone MA, Grossman RL, Mcmillen RT, Liou K-N, Ou SC, Mckeen S, Angevine W, Ikeda K, Chen F (2002) CASE-97: late-morning warming and moistening of the convective boundary layer over the Walnut River Watershed. Boundary-Layer Meteorol 104: 1–52. doi:10.1023/A:1015569104180
LeMone MA, Chen F, Alfieri JG, Tewari M, Geerts B, Miao Q, Grossman RL, Coulter RL (2007) Influence of land cover and soil moisture on the horizontal distribution of sensible and latent heat fluxes in southeast Kansas during IHOP_2002 and CASES-97. J Hydrometeorol 8: 68–87. doi:10.1175/JHM554.1
Lenschow D, Wyngaard J, Pennell W (1980) Mean-field and second-moment budgets in a baroclinic, convective boundary layer. J Atmos Sci 37: 1313–1326. doi:10.1175/1520-0469(1980)037<1313:MFASMB>2.0.CO;2
Letzel MO, Raasch S (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
Mahrt L, Gibson W (1992) Flux decomposition into coherent structures. Boundary-Layer Meteorol 60: 143–168. doi:10.1007/BF00122065
Mahrt L, Sun J, Vickers D, Macpherson JI, Pederson JR, Desjardins RL (1994a) Observations of fluxes and inland breezes over a heterogeneous surface. J Atmos Sci 51: 2484–2499. doi:10.1175/1520-0469(1994)051<2484:OOFAIB>2.0.CO;2
Mahrt L, Desjardins R, Macpherson JI (1994b) Observations of fluxes over heterogeneous surfaces. Boundary-Layer Meteorol 67: 345–367. doi:10.1007/BF00705438
Moeng CH, Wyngaard JC (1988) Spectral analysis of larger-eddy simulations of the convective boundary layer. J Atmos Sci 45: 3573–3587. doi:10.1175/1520-0469(1988)045<3573:SAOLES>2.0.CO;2
Patton EG, Sullivan PP, Moeng C-H (2005) 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
Pielke RA (2001) Influence of the spatial distribution of vegetation and soils on the prediction and soils on the cumulus convective rainfall. Rev Geophys 39: 151–177. doi:10.1029/1999RG000072
Rotunno R (1983) On the linear theory of the land and sea breeze. J Atmos Sci 40: 1999–2009. doi:10.1175/1520-0469(1983)040<1999:OTLTOT>2.0.CO;2
Shen S, Leclerc MY (1995) How large must surface inhomogeneities be before they influence the convective boundary layer structure? A case study. Q J Roy Meteorol Soc 121: 1209–1228. doi:10.1002/qj.49712152603
Skamarock WC (2004) Evaluating mesoscale NWP models using kinetic energy spectra. Mon Weather Rev 132: 3019–3032. doi:10.1175/MWR2830.1
Stull RB (1988) An introduction to boundary layer meteorology. Kluwer Academic Publishers, Dordrecht, p 666
Wang J, Bars RL, Eltahir EA (1996) A stochastic linear theory of mesoscale circulation induced by the thermal heterogeneity of the land surface. J Atmos Sci 53: 3349–3366. doi:10.1175/1520-0469(1996)053<3349:ASLTOM>2.0.CO;2
Weaver CP (2004) Coupling between large-scale atmospheric processes and mesoscale land–atmosphere interactions in the U.S. Southern Great Plains during summer. Part II: mean impacts of the mesoscale. J Hydrometeorol 5: 1247–1258. doi:10.1175/JHM-397.1
Wyngaard JC (2004) Toward numerical modeling in the “Terra Incognita”. J Atmos Sci 16: 1816–1826. doi:10.1175/1520-0469(2004)061<1816:TNMITT>2.0.CO;2
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The National Center for Atmospheric Research is sponsored by the National Science Foundation.
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Kang, SL. Temporal Oscillations in the Convective Boundary Layer Forced by Mesoscale Surface Heat-Flux Variations. Boundary-Layer Meteorol 132, 59–81 (2009). https://doi.org/10.1007/s10546-009-9391-5
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DOI: https://doi.org/10.1007/s10546-009-9391-5