The predictability of near-coastal currents using a baroclinic unstructured grid model   总被引：1，自引：1，他引：0  

Cheryl Ann Blain  Mustafa Kemal Cambazoglu  Robert S. Linzell  Kendra M. Dresback  Randall L. Kolar 《Ocean Dynamics》2012,62(3):411-437

A limited domain, coastal ocean forecast system consisting of an unstructured grid model, a meteorological model, a regional ocean model, and a global tidal database is designed to be globally relocatable. For such a system to be viable, the predictability of coastal currents must be well understood with error sources clearly identified. To this end, the coastal forecast system is applied at the mouth of Chesapeake Bay in response to a Navy exercise. Two-day forecasts are produced for a 10-day period from 4 to 14 June 2010 and compared to real-time observations. Interplay between the temporal frequency of the regional model boundary forcing and the application of external tides to the coastal model impacts the tidal characteristics of the coastal current, even contributing a small phase error. Frequencies of at least 3 h are needed to resolve the tidal signal within the regional model; otherwise, externally applied tides from a database are needed to capture the tidal variability. Spatial resolution of the regional model (3 vs 1 km) does not impact skill of the current prediction. Tidal response of the system indicates excellent representation of the dominant M ₂ tide for water level and currents. Diurnal tides, especially K ₁, are amplified unrealistically with the application of coarse 27-km winds. Higher-resolution winds reduce current forecast error with the exception of wind originating from the SSW, SSE, and E. These winds run shore parallel and are subject to strong interaction with the shoreline that is poorly represented even by the 3-km wind fields. The vertical distribution of currents is also well predicted by the coastal model. Spatial and temporal resolution of the wind forcing including areas close to the shoreline is the most critical component for accurate current forecasts. Additionally, it is demonstrated that wind resolution plays a large role in establishing realistic thermal and density structures in upwelling prone regions.  相似文献   

Stochastically simulated blast-induced ground motion effects on nonlinear response of an industrial masonry chimney     

Kemal Hacıefendioğlu  Emre Alpaslan 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(2):415-427

This paper presents the dynamic response analysis of industrial masonry chimney subjected to artificially generated surface blast induced ground shock by using a three-dimensional finite element model. The effects of surface blast-induced ground shocks on nearby structures depend on the distance between the explosion centre and the structure, and charge weight. Blast-induced ground motions can be represented by power spectral density function and applied to each support point of the 3D finite element model of the industrial masonry system. In this study, a parametric study is mainly conducted to estimate the effect of the blast-induced ground motions on the nonlinear response of a chimney type masonry structure. Therefore, the analysis was carried out for different values of the charge weights and distances from the charge center. The initial crack and propagation of the crack pattern at the base of the chimney were evaluated. Moreover, the maximum stresses and displacements through the height of the chimney were investigated. The results of the study underline that blast-induced ground motions effects should be considered to perform the non-linear dynamic analysis of masonry type chimney structures more accurately.  相似文献   

Author response to “Discussion on ‘The estimation of monthly mean significant wave heights by using artificial neural network and regression methods’” by Tarkan Erdik     

Kemal Günaydın 《Ocean Engineering》2009,36(6-7):537

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