A throughflow model based on the time-marching finite volume approach is described in this paper. The governing equations are derived by circumferentially averaging the three-dimensional Navier-Stokes equations neglec...A throughflow model based on the time-marching finite volume approach is described in this paper. The governing equations are derived by circumferentially averaging the three-dimensional Navier-Stokes equations neglecting the circumferentially non-uniform and viscous terms. An inviscid blade force model similar to the Large-particle method is derived. The viscous blade force has been modeled by the distributed loss model. The convective fluxes of the governing equation are discretized with the Edward’s low-diffusion flux-splitting (LDFSS) scheme. And a point-iterative Symmetric Gauss-Seidel (SGS) scheme is used in the temporal discretization. The throughflow model has been applied to the NASA Rotor 67 and a high-load transonic fan stage ATS-2. The reasonable good agreements with the experiments and the 3D viscous computations show the potential of the method.展开更多
An experiment using the Community Climate System Model(CCSM4), a participant of the Coupled Model Intercomparison Project phase-5(CMIP5), is analyzed to assess the skills of this model in simulating and predicting the...An experiment using the Community Climate System Model(CCSM4), a participant of the Coupled Model Intercomparison Project phase-5(CMIP5), is analyzed to assess the skills of this model in simulating and predicting the climate variabilities associated with the oceanic channel dynamics across the Indo-Pacific Oceans. The results of these analyses suggest that the model is able to reproduce the observed lag correlation between the oceanic anomalies in the southeastern tropical Indian Ocean and those in the cold tongue in the eastern equatorial Pacific Ocean at a time lag of 1 year. This success may be largely attributed to the successful simulation of the interannual variations of the Indonesian Throughflow, which carries the anomalies of the Indian Ocean Dipole(IOD) into the western equatorial Pacific Ocean to produce subsurface temperature anomalies, which in turn propagate to the eastern equatorial Pacific to generate ENSO. This connection is termed the "oceanic channel dynamics" and is shown to be consistent with the observational analyses. However, the model simulates a weaker connection between the IOD and the interannual variability of the Indonesian Throughflow transport than found in the observations. In addition, the model overestimates the westerly wind anomalies in the western-central equatorial Pacific in the year following the IOD, which forces unrealistic upwelling Rossby waves in the western equatorial Pacific and downwelling Kelvin waves in the east. This assessment suggests that the CCSM4 coupled climate system has underestimated the oceanic channel dynamics and overestimated the atmospheric bridge processes.展开更多
The performance of the eddy-resolving LICOM2.0 in simulating the Indonesian Throughflow has been evaluated against the INSTANT data in the present study.The mean vertical structures of the along strait velocities are ...The performance of the eddy-resolving LICOM2.0 in simulating the Indonesian Throughflow has been evaluated against the INSTANT data in the present study.The mean vertical structures of the along strait velocities are simulated well in LICOM2.0,but the large velocities at the bottom of the Lifamatola Passage and the Timor Passage cannot be reproduced by LICOM2.0.The causes are considered to be both the errors in the topography and the tidal mixing at the bottom.Despite several biases in the mean velocities,the mean inflow and outflow volume transports in LICOM2.0 are almost identical to the INSTANT data.Compared with the lower resolution LICOM,the most significant improvement is the better simulation of the partitions of the inflow and outflow transports in individual straits.The outflow for low-resolution LICOM is mainly through the Ombai and Lombok Strait,whereas that for LICOM2.0 is mainly through the Timor Passage.The variability of the vertical structure of velocities and the volume transport are also investigated.LICOM2.0 overestimates the magnitude of the upper-layer currents and the amplitude of the variation.We also found that the largest correlation coefficient occurs in the shallowest strait,the Lombok,whereas the lowest occurs in the Timor Passage,especially in the upper layer.The latter may be caused by the unrealistic transport through the Torres Strait in LICOM2.0.展开更多
The objective of this study is to model the mean and seasonal mass transportof the Pacific to Indian O-cean throughflow using variable-grid global Ocean General CirculationModel (OGCM) with fine grid (1°/6) cover...The objective of this study is to model the mean and seasonal mass transportof the Pacific to Indian O-cean throughflow using variable-grid global Ocean General CirculationModel (OGCM) with fine grid (1°/6) covering the area from 20°S to 60°N and from 98°E to 156°E.The computations show that Indonesian Throughflow (ITF) mass transport, computed as a sum ofthrough-strait transport, has maximum transport in Sept. (17. 5Sv) and minimum transport in Jan. (9.5Sv). The annual mean ITF transport amounts to 14. 5Sv. Twenty-two percent of this transport passesthrough Lombok Strait. Sixty-five percent of this transport passes through Timor Passage.Semi-annual variability is apparent in Lombok and Ombai Straits while annual variability is apparentin Timor Passage.展开更多
基金supported by National Natural Science Foundation of China (50676004, 50736007)"Fan-Zhou" Youth Foundation (20100401)the Fun-damental Research Funds for the Central Universities (YWF-10-02-013)
文摘A throughflow model based on the time-marching finite volume approach is described in this paper. The governing equations are derived by circumferentially averaging the three-dimensional Navier-Stokes equations neglecting the circumferentially non-uniform and viscous terms. An inviscid blade force model similar to the Large-particle method is derived. The viscous blade force has been modeled by the distributed loss model. The convective fluxes of the governing equation are discretized with the Edward’s low-diffusion flux-splitting (LDFSS) scheme. And a point-iterative Symmetric Gauss-Seidel (SGS) scheme is used in the temporal discretization. The throughflow model has been applied to the NASA Rotor 67 and a high-load transonic fan stage ATS-2. The reasonable good agreements with the experiments and the 3D viscous computations show the potential of the method.
基金the National Basic Research Program of China(973 Program)(No.2012CB956000)the Strategic Priority Project of Chinese Academy of Sciences(No.XDA11010301)+2 种基金the National Natural Science Foundation of China(Nos.41421005,U1406401)the Public Welfare Grant of China Meteorological Administration(No.GYHY201306018)the Global Change and Air-Sea Interactions of State Oceanic Administration(No.GASI-03-01-01-05)
文摘An experiment using the Community Climate System Model(CCSM4), a participant of the Coupled Model Intercomparison Project phase-5(CMIP5), is analyzed to assess the skills of this model in simulating and predicting the climate variabilities associated with the oceanic channel dynamics across the Indo-Pacific Oceans. The results of these analyses suggest that the model is able to reproduce the observed lag correlation between the oceanic anomalies in the southeastern tropical Indian Ocean and those in the cold tongue in the eastern equatorial Pacific Ocean at a time lag of 1 year. This success may be largely attributed to the successful simulation of the interannual variations of the Indonesian Throughflow, which carries the anomalies of the Indian Ocean Dipole(IOD) into the western equatorial Pacific Ocean to produce subsurface temperature anomalies, which in turn propagate to the eastern equatorial Pacific to generate ENSO. This connection is termed the "oceanic channel dynamics" and is shown to be consistent with the observational analyses. However, the model simulates a weaker connection between the IOD and the interannual variability of the Indonesian Throughflow transport than found in the observations. In addition, the model overestimates the westerly wind anomalies in the western-central equatorial Pacific in the year following the IOD, which forces unrealistic upwelling Rossby waves in the western equatorial Pacific and downwelling Kelvin waves in the east. This assessment suggests that the CCSM4 coupled climate system has underestimated the oceanic channel dynamics and overestimated the atmospheric bridge processes.
基金supported by the National Basic Research Program of China(2010CB951904 and 2013CB956204)the National Natural Science Foundation of China(41275084,41075059 and 41023002)the Strategic Priority Research Program–Climate Change:Carbon Budget and Related Issues of the Chinese Academy of Sciences(XDA05110302)
文摘The performance of the eddy-resolving LICOM2.0 in simulating the Indonesian Throughflow has been evaluated against the INSTANT data in the present study.The mean vertical structures of the along strait velocities are simulated well in LICOM2.0,but the large velocities at the bottom of the Lifamatola Passage and the Timor Passage cannot be reproduced by LICOM2.0.The causes are considered to be both the errors in the topography and the tidal mixing at the bottom.Despite several biases in the mean velocities,the mean inflow and outflow volume transports in LICOM2.0 are almost identical to the INSTANT data.Compared with the lower resolution LICOM,the most significant improvement is the better simulation of the partitions of the inflow and outflow transports in individual straits.The outflow for low-resolution LICOM is mainly through the Ombai and Lombok Strait,whereas that for LICOM2.0 is mainly through the Timor Passage.The variability of the vertical structure of velocities and the volume transport are also investigated.LICOM2.0 overestimates the magnitude of the upper-layer currents and the amplitude of the variation.We also found that the largest correlation coefficient occurs in the shallowest strait,the Lombok,whereas the lowest occurs in the Timor Passage,especially in the upper layer.The latter may be caused by the unrealistic transport through the Torres Strait in LICOM2.0.
文摘The objective of this study is to model the mean and seasonal mass transportof the Pacific to Indian O-cean throughflow using variable-grid global Ocean General CirculationModel (OGCM) with fine grid (1°/6) covering the area from 20°S to 60°N and from 98°E to 156°E.The computations show that Indonesian Throughflow (ITF) mass transport, computed as a sum ofthrough-strait transport, has maximum transport in Sept. (17. 5Sv) and minimum transport in Jan. (9.5Sv). The annual mean ITF transport amounts to 14. 5Sv. Twenty-two percent of this transport passesthrough Lombok Strait. Sixty-five percent of this transport passes through Timor Passage.Semi-annual variability is apparent in Lombok and Ombai Straits while annual variability is apparentin Timor Passage.
