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P. Marsaleix, F. Auclair, and C. Estournel

1. Introduction In coastal ocean modeling, open boundary conditions (OBCs) have a crucial impact on the inner domain solution. This is largely due to the fact that time scales associated with the propagation of waves throughout the coastal area are comparable to the length of the simulation itself, when they are not much shorter. A barotropic wave can, for instance, cross a 100-m-deep and 100-km-long shelf in about 1 h and a 1 m s −1 internal wave can cross it in about 1 day. This is much

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Haidong Pan, Zheng Guo, and Xianqing Lv

). Treatment of open boundary conditions (OBCs), one of the most important control parameters in the tidal model, remains a great challenge for numerical simulation of tides and tidal currents ( Lardner et al. 1993 ). Since the 1990s, the adjoint method has been widely implemented in the inversion of OBCs. Lardner et al. (1993) achieved effective control of the OBCs in a depth-averaged numerical tidal model by data assimilation. Seiler (1993) successfully estimated the OBCs for a quasigeostrophic ocean

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Sean C. Crosby, William C. O’Reilly, and Robert T. Guza

~60% of the total shoreward wave energy flux ( Fig. 2 ). Swell model prediction skill at nearshore buoy sites is compared for different offshore boundary condition parameterizations. Fig . 2. The 10-yr mean wave conditions at offshore buoy 071. (a) Mean GWM (NOAA-WW3) wave energy predictions (color) vs frequency and direction. (b) GWM- (dashed) and buoy-measured (solid) mean energy flux ( ) vs frequency (integrated over direction). Swell (0.04–0.09 Hz) and sea (0.09–0.25 Hz) frequency bands

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I. Shulman

1. Introduction With the rapidly increasing amount of available observations, results of model simulations, and newly gained knowledge of physical processes, the development of data assimilation methods is in great demand. One of the areas of application of data assimilation methods is the specification of open boundary conditions (OBCs) for limited-area models. The use of data assimilation techniques improves the model predictions and avoids the ill-posed, point-wise treatment of OBCs

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Peter C. Chu, Chenwu Fan, and Laura L. Ehret

observations take place, the solutions are S 1 , S 2 , . . . , S m , which form a solution vector b. Optimization method for determining B Ocean model performance can be measured by the rms error The vector S depends on B. Change of the boundary vector B (boundary conditions) leads to a change of S (solutions). Inversely, we may determine B by minimizing I ; Substitution of (5) into (6) leads to a set of n equations implicitly solvable for b 1 , b 2 , . . . , b

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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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Igor Shulman, James K. Lewis, Alan F. Blumberg, and B. Nicholas Kim

model with greater horizontal resolution showed very similar results with slight differences in the Gulfs of Bohai and Liadong ( Choi 1989 ). In this study, an adaptation of the optimized open boundary conditions presented by Shulman and Lewis (1994 , 1995 , 1996) and Shulman (1997) was tested with respect to the improvement of the model prediction skills of the M 2 tidal amplitudes and phases in the Yellow Sea. In addition, this approach was extended to the assimilation of available sea

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Jie Peng, C. S. B. Grimmond, Xinshu Fu, Yuanyong Chang, Guangliang Zhang, Jibing Guo, Chenyang Tang, Jie Gao, Xiaodong Xu, and Jianguo Tan

yield β profiles not suitable for the S-IC analysis. These are classified as nontypical (NT) days and are also removed from the analysis. Therefore, the climatological analysis is for rain- and fog-free conditions. Although the z i ,icf can be retrieved for individual nonrainy β profiles on a day with rain, they are removed to avoid the impact of significantly varying boundary layer structures on rainy day. Thus, the categories of β profiles identified for analysis are clear (CL) and aerosol

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Zhigang Xu

1. Introduction In the numerical modeling of the ocean circulation in a finite domain, one of the major challenges is the specification of appropriate conditions at the open water boundaries. In contrast to coastal boundaries where a law of no relative motion between the wall and water can be used for conditions, the conditions on open boundaries are subject to great uncertainty. Usually there are neither sufficient observations (if any) nor physical laws to provide a basis for specifying the

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Dong Jiang, Haibo Chen, Guangzhen Jin, and Xianqing Lv

originate from a distant source like LS but are likely generated near the northwestern SCS. For numerical studies of internal tides, the open boundary conditions (OBCs) must be prescribed to complete the model description at open boundaries. They are very important and have a critical impact on the modeling results. However, a major difficulty faced by regional ocean models is concerned with the treatment of the OBCs ( Lardner et al. 1993 ). In practical ocean modeling, on the other hand, the external

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