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Yoichi Ishikawa, Toshiyuki Awaji, and Nobumasa Komori

of the effect of various weighting parameter values on the temporal penalty remains for future work. In evaluating any assimilation scheme, the computational cost is an important factor, and assumes a critical importance in operational forecasting. The memory required for our variational assimilation calculations is of a similar size to that required using the optimal interpolation scheme, since most of the memory is occupied by the forecast error covariance associated with the optimal

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E. Joseph Metzger and Harley E. Hurlburt

have the advantage of using a constant data assimilation and atmospheric forecast model and, thus, are unaffected by product upgrades. The switch in ECMWF products across the 1993/1994 time boundary was investigated to make sure no large-scale response might be introduced into the ocean model. Pacific basin energy levels of the two wind products showed no significant change between the reanalysis/operational (Re/Op) time frames. This was not the case when the ECMWF 10-m winds were examined, hence

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Alberto M. Mestas-Nuñez, Dudley B. Chelton, Micheal H. Freilich, and James G. Richman

1532JOURNAL OF PHYSICAL OCEANOGRAPHY~OLUME 24An Evaluation of ECMWF.Based Climatological Wind Stress FieldsALBERTO M. MESTAS-Nu~Ez,* DUDLEY B. CHELTON, MICHAEL H. FREILICH, AND JAMES G. RICHMANCollege of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon(Manuscript received 25 March 1993, in final form 21 October 1993) ABSTRACT A new mean monthly wind stress climatology based on seven years (1980-1986) of operational weather analyses by the

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S. Y. Annenkov and V. I. Shrira

kurtosis by Annenkov and Shrira (2009a , 2013 ) have shown that in generic situations the dynamic kurtosis remains small both in the absolute value [being O (10 −2 )] and compared to the total value of kurtosis. The scale of required computations rules out this route as an option for operational wave forecasting and many other applications. The second contribution to non-Gaussianity is due to bound harmonics. It manifests in both kurtosis and skewness and is present in any finite-amplitude wave

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Nickitas Georgas

regions of the river, and at known choke points (CPs; potential ice jam sites). c. The New York Harbor Observing and Prediction System The New York Harbor Observing and Prediction System (NYHOPS; Bruno et al. 2006 ) utilizes observations from sensors as well as federal agency forecasts, to create input forcing to a three-dimensional (3D) hydrodynamic operational forecast system (OFS). The model code, Stevens Estuarine and Coastal Ocean Model (sECOM), is a descendant of the Princeton Ocean Model

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Hitoshi Tamura, Takuji Waseda, Yasumasa Miyazawa, and Kosei Komatsu

developed for operational wave forecasting. SRIAM reduces computational costs considerably by utilizing 20 resonance configurations that retain the general properties of the Snl kernel function. Komatsu (1996) showed that SRIAM compared favorably with the rigorous RIAM method for duration-limited wave growth after an abrupt change in wind direction and the evolution of perturbed-equilibrium spectra. However, little is known about the applicability of SRIAM to a more complex wave field. In the

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Ian A. Renfrew, G. W. K. Moore, Peter S. Guest, and Karl Bumke

requires first that the atmospheric boundary layer is realistic and second that the derivation of surface fluxes is carried out using a suitable model formulation. In this study we address these two requirements in turn. First, a time series of observations from a cruise of the R/V Knorr in the Labrador Sea during February and March 1997 is compared to model analyses data. The analyses are the operational analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF), and the reanalyses

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A. Birol Kara, Alan J. Wallcraft, and Harley E. Hurlburt

. 2003 ). Ocean general circulation model (OGCM) simulations generally depend on atmospheric forcing, namely, momentum flux (i.e., wind stress) and scalar fields (e.g., net shortwave and longwave radiation fluxes at the sea surface, air temperature and, air mixing ratio at 10 m above the sea surface) from gridded weather prediction models. Examples of such atmospheric forcing sources include the 15-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA-15) ( Gibson et al. 1999

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Qingxiang Liu, W. Erick Rogers, Alexander Babanin, Jingkai Li, and Changlong Guan

ice models, and (iii) the applicability of these models to operational forecasts. A brief conclusion in section 7 finalizes this paper. 2. Previous works on wave–ice interactions a. Spectral wave modeling in ice-free waters WW3 solves the radiative transfer equation (RTE) to predict the generation, evolution, and dissipation of ocean surface waves. When currents and ice are absent , the deep-water RTE is generally written as follows (e.g., Holthuijsen 2007 ): (1) ∂ N ∂ t + ∇ ⋅ c g N = S T ω

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Alan D. Fox and Stephen J. Maskell

initial fields are resolved on both the coarse grid and the finegrid in the region of the interface in order to minimize the generation of disturbances. Comparison of the results of the nested model with a fine grid everywhere reference calculation shows thenesting technique to be working successfully over reasonably short periods of time integration ( 16 days) suchas may be used operationally for ocean forecasting.1. Introduction This paper develops the type of technique introducedby Spall and

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