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F. Voitus, P. Termonia, and P. Bénard

International (ALADIN) model ( Bubnová et al. 1995 ), and the so-called spectral version of the HIRLAM model ( Haugen and Machenhauer 1993 ). But, because of the contradiction between a local specification of LBCs and the global character of the Fourier spectral discretization, designing stable and accurate well-posed boundary conditions is a daunting task. In Fourier spectral limited-area models, one of the most difficult questions is to combine the periodicity constraint for the Fourier expansion with

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Benoît Vié, Olivier Nuissier, and Véronique Ducrocq

. As physical parameterizations at smaller scales show stronger nonlinearities, convective-scale perturbations grow much faster and even impact the large-scale predictability. The sensitivity to ICs ( Ducrocq et al. 2002 ) is also different between parameterized and resolved convection. Moreover, in addition to the uncertainties on ICs and the model errors, cloud-resolving ensembles must also consider the uncertainty due to lateral boundary conditions (LBCs), since they are run over a limited area

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Piet Termonia, Alex Deckmyn, and Rafiq Hamdi

prediction (NWP) models on limited areas, the lateral boundary conditions (LBCs) have to be specified, but the existing numerical techniques used to impose them in operational models still exhibit, as Warner et al. (1997) properly address, a number of potentially serious limitations. A particular problem discussed in that paper is the one of the LBC temporal resolution . Warner et al. state that, “the time scales of the cross-boundary fluxes must be assessed, and the temporal resolution of the LBCs

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Qin Xu and Robert Davies-Jones

1566 MONTHLY WEATHER REVIEW VOLUM-121 Boundary Conditions for the Psi Equations QiN Xu CIMMS, University of Oklahoma, Norman, Oklahoma ROBERT DAVIES-JONES NOA,4 /ERL, National Severe Storms Laboratory, Norman, Oklahoma (Manuscript received 26 March 1992, in final form 16 November 1992) ABSTRACT

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Katherine A. Lundquist, Fotini Katopodes Chow, and Julie K. Lundquist

1. Introduction Most mesoscale numerical weather prediction (NWP) models use terrain-following coordinates, which accommodate complex terrain by transforming the physical domain onto a Cartesian grid. Phillips (1957) first introduced this coordinate, using the variable sigma to represent the transformed vertical coordinate. This formulation simplifies the application of lower boundary conditions by aligning the lowest coordinate with the topography. Coordinate lines gradually

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William C. Skamarock, Michael G. Duda, Soyoung Ha, and Sang-Hun Park

forecasting for the foreseeable future. Regional models, however, bring with them a number of problems associated with their lateral boundary conditions, including questions concerning the well-posedness of the lateral boundary formulations, the potential for solution mismatches between the driving solution and the evolving regional solution, the need for relaxation or sponge zones next to the lateral boundaries, and issues related to the regional domain size and the degree of downscaling employed with a

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Dale R. Durran, Ming-Jen Yang, Donald N. Slinn, and Randy G. Brown

604 MONTHLY WEATHER REVIEW VOLUME 121Toward More Accurate Wave-Permeable Boundary Conditions DALE R. DURRAN AND MING-JEN YANGDepartment of Atmospheric Sciences, University of Washington, Seattle, Washington DONALD N. SLINNDepartment of Mechanical Engineering, University of Washington, Seattle, Washington RANDY G. BROWNDepartment of Atmospheric Sciences

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Mark Hedley and M. K. Yau

SEPTEMBER 1988 MARK HEDLEY AND M. K. YAU 1721Radiation Boundary Conditions in Numerical Modeling MARK HEDLEY AND M. K. YAUDepartment of Meteorology, McGill University, Montreal, Canada(Manuscript received 21 October 1987, in final form 5 February 1988)ABSTRACT A two-dimensional anelastic model is used to study the propagation of errors arising from the use of openlateral boundaries. Reference experiments were performed

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A. McDonald

incorporate the boundary conditions into equations that describe unidirectional waves traveling out of the area (and into the area when nested). In section 2 we will use this idea to arrive at one-way wave equations for the boundaries that are correct to a well-defined level of approximation. Robert and Yakimiw (1986) point out that, since most boundary strategies contain difficulties that cannot be easily identified when they are considered in the framework of realistic models, it is a good idea to

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James J. Hack and Wayne H. Schubert

1404 MONTHLY WEATHER REVIEW VOLUME ~0~Lateral Bo.undary Conditions for Tropical Cyclone Models JAMES J. HACK AND WAYNE H. SCHUBERTDepartment of Atmospheric Science, Colorado State University, Fort Collins 80523(Manuscript received 20 April 1980, in final form 3 March 1981) Under certain circumstances a large fraction of the energy generated by the release of latent heat ina tropical cyclone can be partitioned to

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