Article : Assessment of the hydraulic slope flow approach using a mesoscale model
Authors : Shapiro, A.School of Meteorology, University of Oklahoma, Norman, Oklahoma, USA, email@example.com, Axelsen, S. L.IMAU, Utrecht University, Utrecht, The Netherlands, firstname.lastname@example.org, Axelsen, S. L.IMAU, Utrecht University, Utrecht, The Netherlands, email@example.com, Steeneveld, G. J.Department of Meteorology and Air Quality,Wageningen University, Wageningen, The Netherlands, firstname.lastname@example.org, Martínez, D.Departament de Física, Universitat de les Illes Balears, Mallorca, Spain, email@example.com,
Abstract : The simplified hydraulic two-layer model for a katabatic flow is analysed using the outputs from a high-resolution mesoscale simulation. A stably stratified night is simulated for the Duero basin, a complex terrain area located in the northern Spanish plateau, with large vertical and horizontal spatial resolution. Well-defined katabatic flows on the basin slopes are generated by the simulation, that are relatively stationary and quasi-bidimensional for some areas in the central part of the night. The bulk quantities used in the two-layer approach as well as the different terms in the equations are computed from the three-dimensional information provided by the mesoscale simulation. This method allows to inspect how well the simplified approach represents the katabatic flow generated by the mesoscale model. The study shows that the hydraulic model allows for a comprehensive analysis of the basic mechanisms of the slope flows but is not able to close the budget equations, since the residuals are large.
Bibliography : Ball, F.K. (1956), The theory of strong katabatic winds, Aust. J. Phys. 9, 373-386.
Bravo, M., T. Mira, M.R. Soler, and J. Cuxart (2008), Intercomparison and evaluation of MM5 and meso-NH mesoscale models in the stable boundary layer, Bound.-Layer Meteor. 128, 77-101.
Clements, C.B., C.D. Whiteman, and J. D. Horel (2003), Cold-air-pool structure and evolution in a mountain basin: Peter Sinks, Utah, J. Appl. Meteorol. 42, 752-768.
Cuxart, J., P. Bougeault, and J.-L. Redelsperger (2000), A turbulence scheme allowing for mesoscale and large-eddy simulations, Quart. J. Roy. Met. Soc. 126, 1-30.
Cuxart, J., M.A. Jiménez, and D. Martínez (2007), Nocturnal meso-beta and katabatic flows on a midlatitude island, Monthly Weath. Rev. 135, 918-932.
Doran, J., T.W. Horst, and C.D. Whiteman (1990), The development and structure of nocturnal slope winds in a simple valley, Bound.-Layer Meteor. 52, 41-68.
Doran, J., J. Fast, and J. Horel (2002), The VTMX 2000 campaign, Bull. Am. Meteor. Soc. 83, 537-551.
Fitzjarrald, D.R. (1984), Katabatic wind in opposing flow, J. Atmos. Sci. 41, 1143-1158.
Haiden, T. (2003), On the pressure field in the slope wind layer. Notes and correspondence, J. Atmos. Sci. 60, 1632-1635.
Haiden, T., and C.D. Whiteman (2005), Katabatic flow mechanisms on a low-angle slope, J. Appl. Meteorol. 44, 113-126.
Jiménez, M.A., A. Mira, J. Cuxart, A. Luque, A. Alonso, and J.A. Guijarro (2008), Verification of a clear-sky mesoscale simulation using satellite-derived surface temperatures, Monthly Weath. Rev. 136, 5148-5161.
Kondo, J., and T. Sato (1988), A simple model of drainage flow on a slope, Bound.-Layer Meteor. 43, 103-123.
Lafore, J.P., J. Stein, N. Asencio, P. Bougeault, V. Ducrocq, J. Duron, C. Fisher, P. Héreil, P. Mascart, J.P. Pinty, J.-L. Redelsperger, E. Richard, and J. Vilá-Guerau de Arellano (1998), The Meso-NH atmospheric simulation system. Part I: Adiabatic formulation and control simulation, Ann. Geophys. 16, 90-109.
Mahrt, L. (1982), Momentum balance of gravity flows, J. Atmos. Sci. 39, 2701-2711.
Manins, P.C., and B.L. Sawford (1979a), A model of katabatic winds, J. Atmos. Sci. 36, 619-630.
Manins, P.C., and B.L. Sawford (1979b), Katabatic winds: A field case study, Quart. J. Roy. Met. Soc. 105, 1011-1025.
Martínez, D., M.A. Jiménez, J. Cuxart, and L. Mahrt (2009), Heterogeneous nocturnal cooling in a large basin under very stable conditions (submitted to Bound.-Layer Meteor.).
Morcrette, J.-J. (1990), Impact of changes to the radiation transfer parameterizations plus cloud optical. Properties in the ECMWF model, Monthly Weath. Rev. 118, 847-873.
Noilhan, J., and S. Planton (1989), A simple parameterization of land surface processes for meteorological models, Monthly Weath. Rev. 117, 536-549.
Renfrew, I.A. (2004), The dynamics of idealized katabatic flow over a moderate slope and ice shelf, Quart. J. Roy. Met. Soc. 130, 1023-1045.
Savage, L.C. I., S. Zhong, W. Yao, W.J.O. Brown, T.W. Horst, and C.D. Whiteman (2008), An observational and numerical study of a regional-scale downslope flow in northern Arizona, J. Geophys. Res. 113, D14114.
Shapiro, A., and E. Fedorovich (2007), Katabatic flows along a differentially Cooley sloping surface, J. Fluid. Mech. 571, 149-175.
Smith, C.M., and E.D. Skyllingstad (2005), Numerical simulation of a katabatic flow with changing slope angle, Monthly Weath. Rev. 133, 3065-3080.
Zhong, S., and C.D. Whiteman (2008), Downslope flows on a low-angle slope and their interactions with valley inversions. Part II: Numerical modeling, J. Appl. Meteor. Climatol. 47, 2039-2057.
Qute : Shapiro, A. ,Axelsen, S. L. ,Axelsen, S. L. ,Steeneveld, G. J. ,Martínez, D. ,Martínez, D. , Assessment of the hydraulic slope flow approach using a mesoscale model. Acta Geophysica Vol. 57, no. 4/2009