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David L. Williamson and Gerald L. Browning

inconjunction with the NCAR Global Circulation Model is described including deta/ls of the lateral boundary conditions. One set of experiments is described for which a 2- global simulation provides the correct orcontrol data against which 2- LAM forecasts are compared. Three cases are considered in which the LAMinflow boundary values are provided by the 2- global forecast, a 5* global forecast, or are held fixed equalto the initial values. Forecasts produced by the LAM with finer grids (up to [*) are also

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Chungu Lu and Gerald L. Browning

open boundaries in a limited-area model. Previous analyses of applications of the 4DVAR method to numerical weather forecasting have mostly been conducted for a set of ordinary differential equations (e.g., Daley 1991 ; Xu 1996 ; Lu and Browning 1998 ) or a set of partial differential equations with periodic boundary conditions (e.g., Lewis and Derber 1985 ; LeDimet and Talagrand 1986 ; Talagrand and Courtier 1987 ; Lu and Browning 2000 ). When one deals with 4DVAR data assimilations for a

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Toshihisa Itano and Akira Kasahara

-dimensional perturbations (e.g., Stone 1966 , 1970 ; Gu et al. 1998 )—have been studied. [A comprehensive review of symmetric instability and its applicability to actual atmospheric and oceanic phenomena is given by Schultz and Schumacher (1999) .] Among these factors, an enigmatic factor that deserves attention is the effect of boundary conditions. While a number of studies on symmetric instability were carried out in an unbounded domain (i.e., without imposing any boundary conditions), there are also a number of

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Carl E. Pearson and Donald F. Winter

AUGUST 1984 CARL E. PEARSON AND DONALD F. WINTER 1307On Tidal Motion in a Stratified Inlet, with Particular Reference to Boundary Conditions CARL E. PEARSON AND DONALD F. WINTER University of Washington, Seattle, WA 98195 (Manuscript received 21 March 1983, in final form 4 June 1984) ABSTRACT The method of characteristics is used to provide

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Lucas M. Harris and Shian-Jiann Lin

1. Introduction Global models have many advantages for climate simulation and medium-range weather prediction. Global models do not need externally imposed lateral boundary conditions (BCs), and so there are no issues with boundary errors contaminating the solution, nor inconsistency between the model dynamics and that of the imposed BCs, two major problems for limited-area models ( Warner et al. 1997 ). Global models also allow synoptic- and planetary-scale features to be better represented

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T. Jung, M. J. Miller, and T. N. Palmer

): the lower boundary conditions, the tropical atmosphere, and the stratosphere. To this end a relaxation technique (also sometimes called nudging) is used in which prognostic fields are relaxed toward reanalysis data during the course of the integration. In this way it is possible to artificially suppress the development of forecast errors in certain regions of the globe (e.g., tropical atmosphere). The relaxation technique is a well-established technique in the atmospheric sciences. It has been

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Andrew J. Weaver and E. S. Sarachik

1470 JOURNAL OF PHYSICAL OCEANOGRAPHY VOLUMe21The Role of Mixed Boundary Conditions in Numerical Models of the Ocean's Climate* ANDREW J. WEAVER* *Department of Meteorology, McGill University, Montreal, Quebec, Canada E. S. $AgACHIKJoint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, Washington (Manuscript received 27 June

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Olivier Arzel, Thierry Huck, and Alain Colin de Verdière

thermohaline circulation is very sensitive to air–sea heat and freshwater fluxes, and two types of surface boundary conditions are traditionally used for temperature and salinity. Nudging the surface variables to their climatologies allows one to reconstruct the deep fields but, not surprisingly, this choice leads to steady states. The other alternative is to use flux boundary conditions (as for the wind forcing of the ocean). In this case the underlying assumption is that, whatever happens in the ocean

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Lichuan Wu, Anna Rutgersson, and Erik Nilsson

development is needed. To fully consider the surface wave influences and propose a new framework including the swell influence, the swell-induced momentum flux as well as the swell influence on atmospheric mixing are investigated based on LESs of wind-following swell conditions in the present study. The swell influences are incorporated into the Mellor–Yamada–Nakanishi–Niino (MYNN) boundary layer parameterization in the single-column version of the Weather Research and Forecasting Model (WRF-SCM) to test

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Xingye Ni, Jinyu Sheng, and Weibing Feng

absorbed as it approaches the sponger layer. The main disadvantage of the sponge layer OBC is that the external flow conditions cannot be specified at the model open boundary. Lastiwka et al. (2009) implemented the first general open boundary condition for the SPH method by removing outgoing particles from the outflow (downstream) buffer zones and adding new particles into the inflow (or upstream) buffer zones. The variables of the particles in the buffer zones are specified by the characteristic open

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