In this study, the momentum equations describing an atmospheric flow over a NW Pacific region of Mexico are solved numerically. In order to capture the complex flow-topography interactions with detail, a combination o...In this study, the momentum equations describing an atmospheric flow over a NW Pacific region of Mexico are solved numerically. In order to capture the complex flow-topography interactions with detail, a combination of a numerical wind model in full 3D curvilinear coordinates, along with a high resolution boundary-fitted grid is used. Boundary conditions were obtained from ten years (2002-2012) of measured offshore wind data. Prevailing winds from April to September during that period of observations were selected for the simulations. For the cases analyzed, it was found that at the points of the study region (PSS, PSM, PM), wind speed increased about 10% to 20% of its offshore values, while inland they decreased about 86% to 96%. This spatial behavior agreed very well with the observed local winds. A coastal jet (CJ), 35 km long with speeds about 1.5 - 2 m/s, emanating from PSS was found for NNW winds. Modeled winds were also used to compute wind stresses, wind stress curl, and CUI fields. Wind stress values agreed very well to those reported in the literature. High values of wind stress curl, and CUI were found at the lee of the points (PSS, PSM, PM). Indirect estimations of sea surface currents were about 15 - 20 cm/s offshore and 5 - 10 cm/s at the coast.展开更多
A series of numerical experiments from a barotropic configuration of the General Curvilinear Ocean Model (GCOM) was conducted to analyze the response to infragravity (IG) waves of the Port of Ensenada, located within ...A series of numerical experiments from a barotropic configuration of the General Curvilinear Ocean Model (GCOM) was conducted to analyze the response to infragravity (IG) waves of the Port of Ensenada, located within Bahia de Todos Santos (BTS), west coast of Mexico. Experiments with forcing frequencies f = 50?1 min?1, f = 30?1 min?1, f = 25?1 min?1 and f = 16.66?1 min?1 showed the expected increase of energy at the corresponding forcing frequency band and also the appearance of secondary peaks of energy at frequency bands f = 8.33?1 min?1 and f = 4.16?1 min?1 which were identified as modes f<sub>1 </sub>and f<sub>2</sub>;being the band at f = 16.66?1 min?1 the zeroth f<sub>0</sub> mode. Maximum peak of spectral energy from the numerical experiments was found at frequency band f<sub>0</sub> = 16.66?1 min?1 which agreed with the estimated maximum value of the amplification factor and with the T<sub>0</sub> mode of oscillation of the port. Distribution of amplitudes inside PE for modes f<sub>0</sub>, f<sub>1</sub> and f<sub>2</sub> were also presented. Mode f<sub>0</sub> represents a quarter-wave oscillation with amplitudes of the same sign;mode f<sub>1</sub> has two nodal lines and mode f<sub>2</sub> presents and additional one. Corresponding harbor currents were also calculated, they were in the range 20 - 160 cm?s?1. Finally, in order to elucidate the source of the external signals found in the spectral analysis of this study, the natural oscillation modes of the BTS were estimated. Although more studies are needed, BTS oscillation mode T<sub>2</sub> = 16.82 min, was identified as the external forcing that excites larger oscillations within the port.展开更多
文摘In this study, the momentum equations describing an atmospheric flow over a NW Pacific region of Mexico are solved numerically. In order to capture the complex flow-topography interactions with detail, a combination of a numerical wind model in full 3D curvilinear coordinates, along with a high resolution boundary-fitted grid is used. Boundary conditions were obtained from ten years (2002-2012) of measured offshore wind data. Prevailing winds from April to September during that period of observations were selected for the simulations. For the cases analyzed, it was found that at the points of the study region (PSS, PSM, PM), wind speed increased about 10% to 20% of its offshore values, while inland they decreased about 86% to 96%. This spatial behavior agreed very well with the observed local winds. A coastal jet (CJ), 35 km long with speeds about 1.5 - 2 m/s, emanating from PSS was found for NNW winds. Modeled winds were also used to compute wind stresses, wind stress curl, and CUI fields. Wind stress values agreed very well to those reported in the literature. High values of wind stress curl, and CUI were found at the lee of the points (PSS, PSM, PM). Indirect estimations of sea surface currents were about 15 - 20 cm/s offshore and 5 - 10 cm/s at the coast.
文摘A series of numerical experiments from a barotropic configuration of the General Curvilinear Ocean Model (GCOM) was conducted to analyze the response to infragravity (IG) waves of the Port of Ensenada, located within Bahia de Todos Santos (BTS), west coast of Mexico. Experiments with forcing frequencies f = 50?1 min?1, f = 30?1 min?1, f = 25?1 min?1 and f = 16.66?1 min?1 showed the expected increase of energy at the corresponding forcing frequency band and also the appearance of secondary peaks of energy at frequency bands f = 8.33?1 min?1 and f = 4.16?1 min?1 which were identified as modes f<sub>1 </sub>and f<sub>2</sub>;being the band at f = 16.66?1 min?1 the zeroth f<sub>0</sub> mode. Maximum peak of spectral energy from the numerical experiments was found at frequency band f<sub>0</sub> = 16.66?1 min?1 which agreed with the estimated maximum value of the amplification factor and with the T<sub>0</sub> mode of oscillation of the port. Distribution of amplitudes inside PE for modes f<sub>0</sub>, f<sub>1</sub> and f<sub>2</sub> were also presented. Mode f<sub>0</sub> represents a quarter-wave oscillation with amplitudes of the same sign;mode f<sub>1</sub> has two nodal lines and mode f<sub>2</sub> presents and additional one. Corresponding harbor currents were also calculated, they were in the range 20 - 160 cm?s?1. Finally, in order to elucidate the source of the external signals found in the spectral analysis of this study, the natural oscillation modes of the BTS were estimated. Although more studies are needed, BTS oscillation mode T<sub>2</sub> = 16.82 min, was identified as the external forcing that excites larger oscillations within the port.
