Boundary-Layer Meteorology

, Volume 132, Issue 1, pp 59–81 | Cite as

Temporal Oscillations in the Convective Boundary Layer Forced by Mesoscale Surface Heat-Flux Variations

Article

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.

Keywords

Boundary-layer parameterization Energy cascade Organized motions Spectral gap Surface heat-flux variation Temporal oscillation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 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 CrossRefGoogle Scholar
  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 CrossRefGoogle Scholar
  3. Bannon PR, Chagnon JM, James RP (2006) Mass conservation and the anelastic approximation. Mon Weather Rev 134: 2989–3005. doi:10.1175/MWR3228.1 CrossRefGoogle Scholar
  4. 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 CrossRefGoogle Scholar
  5. Bryan GH, Rotunno R (2008) Gravity currents in a deep anelastic atmosphere. J Atmos Sci 65: 536–556. doi:10.1175/2007JAS2443.1 CrossRefGoogle Scholar
  6. 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 CrossRefGoogle Scholar
  7. 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 CrossRefGoogle Scholar
  8. 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 CrossRefGoogle Scholar
  9. 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: 641–647Google Scholar
  10. 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 CrossRefGoogle Scholar
  11. 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 CrossRefGoogle Scholar
  12. 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 CrossRefGoogle Scholar
  13. 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 CrossRefGoogle Scholar
  14. Esau IN (2007) Amplification of turbulent exchange over wide Arctic leads: large-eddy simulation study. J Geophys Res 112: D08109. doi:10.1029/2006JD007225 CrossRefGoogle Scholar
  15. 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 CrossRefGoogle Scholar
  16. 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 Google Scholar
  17. 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 Google Scholar
  18. 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 CrossRefGoogle Scholar
  19. 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 CrossRefGoogle Scholar
  20. 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 CrossRefGoogle Scholar
  21. 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 CrossRefGoogle Scholar
  22. 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 CrossRefGoogle Scholar
  23. 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 CrossRefGoogle Scholar
  24. 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 CrossRefGoogle Scholar
  25. 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 CrossRefGoogle Scholar
  26. 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 CrossRefGoogle Scholar
  27. Mahrt L, Gibson W (1992) Flux decomposition into coherent structures. Boundary-Layer Meteorol 60: 143–168. doi:10.1007/BF00122065 CrossRefGoogle Scholar
  28. 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 CrossRefGoogle Scholar
  29. Mahrt L, Desjardins R, Macpherson JI (1994b) Observations of fluxes over heterogeneous surfaces. Boundary-Layer Meteorol 67: 345–367. doi:10.1007/BF00705438 CrossRefGoogle Scholar
  30. 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 CrossRefGoogle Scholar
  31. 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 CrossRefGoogle Scholar
  32. 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 CrossRefGoogle Scholar
  33. 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 CrossRefGoogle Scholar
  34. 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 CrossRefGoogle Scholar
  35. Skamarock WC (2004) Evaluating mesoscale NWP models using kinetic energy spectra. Mon Weather Rev 132: 3019–3032. doi:10.1175/MWR2830.1 CrossRefGoogle Scholar
  36. Stull RB (1988) An introduction to boundary layer meteorology. Kluwer Academic Publishers, Dordrecht, p 666Google Scholar
  37. 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 CrossRefGoogle Scholar
  38. 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 Google Scholar
  39. 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 CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Advanced Study Program, National Center for Atmospheric ResearchBoulderUSA
  2. 2.Department of MeteorologyThe Pennsylvania State UniversityUniversity ParkUSA

Personalised recommendations