Turbulence generation by mountain wave breaking in flows with directional wind shear

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Guarino, M. V., Teixeira, M. A. C. ORCID: https://orcid.org/0000-0003-1205-3233 and Ambaum, M. H. P. ORCID: https://orcid.org/0000-0002-6824-8083 (2016) Turbulence generation by mountain wave breaking in flows with directional wind shear. Quarterly Journal of the Royal Meteorological Society, 142 (700). pp. 2715-2726. ISSN 1477-870X doi: 10.1002/qj.2862

Abstract/Summary

Mountain wave breaking, and the resulting potential for the generation of turbulence in the atmosphere, is investigated using numerical simulations of idealized, nearly hydrostatic atmospheric flows with directional wind shear over an axisymmetric isolated mountain. These simulations, which use the WRF-ARWmodel, differ in degree of flow non-linearity and shear intensity, quantified through the dimensionless mountain height and the Richardson number of the incoming flow, respectively. The aim is to diagnose wave breaking based on large-scale flow variables. The simulation results have been used to produce a regime diagram giving a description of the wave breaking behaviour in Richardson number–dimensionless mountain height parameter space. By selecting flow overturning occurrence as a discriminating factor, it was possible to split the regime diagram into sub-regions with and without wave breaking. When mountain waves break, the associated convective instability leads to turbulence generation (which is one of the known forms of Clear Air Turbulence, also known as CAT). Thus, regions within the simulation domain where wave breaking and the development of CAT are expected have been identified. The extent of these regions increases with terrain elevation and background wind shear intensity. Analysis of the model output, supported by theoretical arguments, suggest the existence of a link between wave breaking and the relative orientations of the incoming wind vector and the horizontal velocity perturbation vector. More specifically, in a wave breaking event, due to the effect of critical levels, the background wind vector and the wave-number vector of the dominant mountain waves are perpendicular. It is shown that, at least for the wind profile employed in the present study, this corresponds to a situation where the background wind vector and the velocity perturbation vector are also approximately perpendicular.

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Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/65952
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	Gravity waves, Wave breaking, Turbulence, 3D mountains, Directional shear
Publisher	Royal Meteorological Society
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Funders:	European Commission	The sponsoring bodies who contributed funding for the creation of this item. Example: NERC Example: The Royal Society of Chemistry A pick list of funders may appear as you type in the funder's name in full or as an acronym. Select a correct match to complete the field or type in a new entry in full. For new entries, the full name is preferred.
Projects:	Global to Local Impacts of Flow over Orography (GLIMFLO) Funded by: European Commission (PCIG13-GA-2013-618016 - £71,429) Local Lead (PI): Miguel Teixeira 1 September 2013 - 31 August 2017	Click Add to select your project (received at Reading) from an autocomplete list.

Deposit Details

Date Deposited:	07 Jul 2016 09:31	Date item deposited into CentAUR
Last Modified:	23 Jun 2024 03:56	Date item last modified

References

Ambaum MHP, Marshall DP. 2005. The effects of stratification on flow separation. J. Atmos. Sci. 62: 2618–2625. Baines PG. 1998. Topographic effects in stratified flows. Cambridge University Press. Bauer MH, Mayr GJ, Vergeiner I, Pichler H. 2000. Strongly nonlinear flow over and around a three-dimensional mountain as a function of the horizontal aspect ratio. J. Atmos. Sci. 57: 3971–3991. Broad AS. 1995. Linear theory of momentum fluxes in 3-d flows with turning of the mean wind with height. Q. J. R. Meteorol. Soc. 121: 1891–1902. Businger JA. 1969. Note on the critical richardson number(s). Q. J. R. Meteorol. Soc. 95: 653–654. Clark TL, Peltier WR. 1984. Critical level reflection and the resonant growth of nonlinear mountain waves. J. Atmos. Sci. 41: 3122–3134. Doyle J, Jiang Q. 2006. Observations and numerical simulations of mountain waves in the presence of directional wind shear. Q. J. R. Meteorol. Soc. 132: 1877–1905. Doyle JD. 2004. Evaluation of topographic flow simulations from coamps and wrf. In: 20th Conference on Weather Analysis and Forecasting/16th Conference on Numerical Weather Prediction. Eliassen A, Palm E. 1960. On the transfer of energy in stationary mountain waves. Geofys. Publ. 22: 1–23. Grubi˘si´c V, Smolarkiewicz PK. 1997. The effect of critical levels on 3d orographic flows: linear regime. J. Atmos. Sci. 54: 1943–1960. Hahn DC. 2007. Evaluation of wrf performance for depicting orographicallyinduced gravity waves in the stratosphere. Technical report, DTIC Document. Hines CO. 1971. Generalizations of the richardson criterion for the onset of atmospheric turbulence. Q. J. R. Meteorol. Soc. 97: 429–439. Holton JR, Hakim GJ. 2012. An introduction to dynamic meteorology. Academic press. Jiang Q, Doyle JD. 2008. On the diurnal variation of mountain waves. J. Atmos. Sci. 65: 1360–1377. Knight H, Broutman D, Eckermann SD. 2015. Integral expressions for mountain wave steepness. Wave Motion 56: 1–13. Laprise R, Peltier WR. 1989. On the structural characteristics of steady finiteamplitude mountain waves over bell-shaped topography. J. Atmos. Sci. 46: 586–595. Lilly DK. 1978. A severe downslope windstorm and aircraft turbulence event induced by a mountain wave. J. Atmos. Sci. 35: 59–77. Lilly DK, Kennedy PJ. 1973. Observations of a stationary mountain wave and its associated momentum flux and energy dissipation. J. Atmos. Sci. 30: 1135–1152. Lin YL. 2007. Mesoscale dynamics. Cambridge University Press. Lindzen RS, Tung KK. 1976. Banded convective activity and ducted gravity waves. Mon. Wea. Rev. 104: 1602–1617. Long RR. 1953. Some aspects of the flow of stratified fluids: I. a theoretical investigation. Tellus 5: 42–58. Lott F, Miller MJ. 1997. A new subgrid-scale orographic drag parametrization: Its formulation and testing. Q. J. R. Meteorol. Soc. 127: 101–127. Mahalov A, Moustaoui M, Nicolaenko B. 2009. Three- dimensional instabilities in non-parallel shear stratified flows. Kinetic and Related Models 2: 215–229. McFarlane NA. 1987. The effect of orographically excited gravity wave drag on the general circulation of the lower stratosphere and troposphere. J. Atmos. Sci. 44: 1775–1800. Miles JW. 1961. On the stability of heterogeneous shear flows. J. Fluid Mech. 10: 496–508. Miles JW, Huppert HE. 1969. Lee waves in a stratified flow. part 4. perturbation approximations. J. Fluid Mech. 35: 497–525. Miranda PMA, James IN. 1992. Non-linear three-dimensional effects on gravity-wave drag: Splitting flow and breaking waves. Q. J. R. Meteorol. Soc. 118: 1057–1081. Nappo CJ. 2012. An introduction to atmospheric gravity waves, 2nd ed. Academic Press. O´ lafsson H, Bougeault P. 1997. The effect of rotation and surface friction on orographic drag. J. Atmos. Sci. 54: 193–210. Peng MS, Thompson WT. 2003. Some aspects of the effect of surface friction on flows over mountains. Q. J. R. Meteorol. Soc. 129: 2527–2557. Sharman RD, Doyle JD, Shapiro MA. 2012a. An investigation of a commercial aircraft encounter with severe clear-air turbulence over western greenland. J. Appl. Meteor. Climatol. 51: 42–53. Sharman RD, Trier SB, Lane TP, Doyle JD. 2012b. Sources and dynamics of turbulence in the upper troposphere and lower stratosphere: A review. Geophys. Res. Lett. 39: L12 803. Shutts G. 1995. Gravity-wave drag parametrization over complex terrain: The effect of critical-level absorption in directional wind-shear. Q. J. R. Meteorol. Soc. 121: 1005–1021. Shutts GJ. 1998. Stationary gravity-wave structure in flows with directional wind shear. Q. J. R. Meteorol. Soc. 124: 1421–1442. Shutts GJ, Gadian A. 1999. Numerical simulations of orographic gravity waves in flows which back with height. Q. J. R. Meteorol. Soc. 125: 2743– 2765. Skamarock WC, Klemp JB, Dudhia J, Gill DO, Barker DM, Wang W, Powers JG. 2005. A description of the advanced research wrf version 2. Technical report, DTIC Document. Smith RB. 1980. Linear theory of stratified hydrostatic flow past an isolated mountain. Tellus 32: 348–364. Smith RB. 1989. Mountain-induced stagnation points in hydrostatic flow. Tellus 41A: 270–274. Smolarkiewicz PK, Rotunno R. 1989. Low froude number flow past three dimensional obstacles. part 1: Baroclinically generated lee vortices. J. Atmos. Sci 46: 1154–1164. Teixeira MAC, Miranda PMA. 2009. On the momentum fluxes associated with mountain waves in directionally sheared flows. J. Atmos. Sci. 66: 3419–3433. Teixeira MAC, Miranda PMA, Valente MA. 2004. An analytical model of mountain wave drag for wind profiles withshear and curvature. J. Atmos. Sci. 61: 1040–1054. Teixeira MAC, Yu CL. 2014. The gravity wave momentum flux in hydrostatic flow with directional shear over elliptical mountains. Eur. J. Mech. B - Fluids 47: 16–31. Turner JS. 1973. Buoyancy effects in fluids. Cambridge University Press. Xu X, Wang Y, Xue M. 2012. Momentum flux and flux divergence of gravity waves in directional shear flows over three-dimensional mountains. J. Atmos. Sci. 69: 3733–3744. Xu X, Xue M, Wang Y. 2013. Gravity wave momentum flux in directional shear flows over three-dimensional mountains: Linear and nonlinear numerical solutions as compared to linear analytical solutions. J. Geophys. Res-Atmos. 118: 7670–7681.

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