On the basis of the European Centre for Medium-range Weather Forecasts （ECMWF） 20 a wind field reanalysis data, the wave field of the north area of the South China Sea is calculated with the combination of the HIRHA...On the basis of the European Centre for Medium-range Weather Forecasts （ECMWF） 20 a wind field reanalysis data, the wave field of the north area of the South China Sea is calculated with the combination of the HIRHAM wind field model and the SWAN wave model. Then a significant wave height compared with the E1 Nifio index to study the relationships between these variables. The following conclusions are drawn： （1） the wave height of the South China Sea has a strong seasonal variation, the wave height is much larger in winter than in summer; （2） in the South China Sea, the monthly average wave height of the north area has a negative correlation with the Nifio3.4 index, most area of the South China Sea has a moderate correlation and the area between Taiwan Province of China and Philippines is highly correlated; and （3） in the strong E1 Nifio years, the significant wave height in the north area of the South China Sea is significantly smaller than in other years; if the E1 Nifio index variability is greater, the wave height decreases. In contrast, the significant wave height in the north area of the South China Sea is larger in the strong La Nifia years.展开更多
A three-dimensional mathematical model using volume-of-fluid method is developed to investigate the heat transfer, fluid flow and keyhole dynamics during electron beam welding of 2219 aluminum alloy plate. In the mode...A three-dimensional mathematical model using volume-of-fluid method is developed to investigate the heat transfer, fluid flow and keyhole dynamics during electron beam welding of 2219 aluminum alloy plate. In the model, an adaptive heat source is employed to simulate the heating process of electron beam. Fluid flow is mainly driven by surface tension, thermo-capillary force, recoil pressure, hydrostatic pressure and thermal buoyancy. The thermal-fluid transport behaviors of welding pool during the drilling and backfilling stages of keyhole and the formation reason of the nail-shaped weld with an arc crater are systematically analyzed. Finally, all calculation results are validated by experiments and show good agreements.展开更多
A three-dimensional,high resolution,Finite Volume Coastal Ocean Model（FVCOM） is used to diagnose the influences of winds during the fall of 2001 on the salt balance of the Tampa Bay.To distinguish the wind effecting...A three-dimensional,high resolution,Finite Volume Coastal Ocean Model（FVCOM） is used to diagnose the influences of winds during the fall of 2001 on the salt balance of the Tampa Bay.To distinguish the wind effecting,two experiments are designed：one is driven by tides and rivers;the other is driven by tides,rivers and winds.First,the salinity change induced by wind is provided.Wind forcing can significantly increase the salinity inside the Tampa Bay,along with decreases of horizontal and vertical salt gradients.Subsequently,the salt balance principles are detailed addressed.The primary salt balance is between the total（horizontal plus vertical）advective salt flux divergence and vertical diffusive salt flux divergence except at the channel bottom where horizontal diffusive salt flux divergence comes into play.At last,the salt balance variation induced by winds is further addressed.Wind forcing does not change the relative importance of salt balance terms.The variations of the salt balance terms influenced by winds are highly dependent on the specific locations.Besides,the variations of the total advective salt flux divergence and the vertical diffusive salt flux divergence are nearly couterbalance,and both of two terms are much greater than that of the horizontal diffusive salt flux divergence.展开更多
Results of the Ocean General Circulation Model for the Earth Simulator（OFES） from January 1977 to December2006 are used to investigate mesoscale eddies near the Ryukyu Islands. The results show that：（1） Larger ed...Results of the Ocean General Circulation Model for the Earth Simulator（OFES） from January 1977 to December2006 are used to investigate mesoscale eddies near the Ryukyu Islands. The results show that：（1） Larger eddies are mainly east of Taiwan, above the Ryukyu Trench and south of the Shikoku Island. These three sea areas are all in the vicinity of the Ryukyu Current.（2） Eddies in the area of the Ryukyu Current are mainly anticyclonic, and conducive to that current. The transport of water east of the Ryukyu Islands is mainly toward the northeast.（3）The Ryukyu Current is significantly affected by the eddies. The lower the latitude, the greater these effects.However, the Kuroshio is relatively stable, and the effect of mesoscale eddies is not significant.（4） A warm eddy south of the Shikoku Island break away from the Kuroshio and move southwest, and is clearly affected by the Ryukyu Current and Kuroshio. Relationships between the mesoscale eddies, Kuroshio meanders, and Ryukyu Current are discussed.展开更多
文摘On the basis of the European Centre for Medium-range Weather Forecasts （ECMWF） 20 a wind field reanalysis data, the wave field of the north area of the South China Sea is calculated with the combination of the HIRHAM wind field model and the SWAN wave model. Then a significant wave height compared with the E1 Nifio index to study the relationships between these variables. The following conclusions are drawn： （1） the wave height of the South China Sea has a strong seasonal variation, the wave height is much larger in winter than in summer; （2） in the South China Sea, the monthly average wave height of the north area has a negative correlation with the Nifio3.4 index, most area of the South China Sea has a moderate correlation and the area between Taiwan Province of China and Philippines is highly correlated; and （3） in the strong E1 Nifio years, the significant wave height in the north area of the South China Sea is significantly smaller than in other years; if the E1 Nifio index variability is greater, the wave height decreases. In contrast, the significant wave height in the north area of the South China Sea is larger in the strong La Nifia years.
文摘A three-dimensional mathematical model using volume-of-fluid method is developed to investigate the heat transfer, fluid flow and keyhole dynamics during electron beam welding of 2219 aluminum alloy plate. In the model, an adaptive heat source is employed to simulate the heating process of electron beam. Fluid flow is mainly driven by surface tension, thermo-capillary force, recoil pressure, hydrostatic pressure and thermal buoyancy. The thermal-fluid transport behaviors of welding pool during the drilling and backfilling stages of keyhole and the formation reason of the nail-shaped weld with an arc crater are systematically analyzed. Finally, all calculation results are validated by experiments and show good agreements.
基金The Scientific Research Foundation of Third Institute of Oceanography,State Oceanic Administration under contract No.2014025The National Natural Science Foundation of China under contract Nos.41076003 and 41406070
文摘A three-dimensional,high resolution,Finite Volume Coastal Ocean Model（FVCOM） is used to diagnose the influences of winds during the fall of 2001 on the salt balance of the Tampa Bay.To distinguish the wind effecting,two experiments are designed：one is driven by tides and rivers;the other is driven by tides,rivers and winds.First,the salinity change induced by wind is provided.Wind forcing can significantly increase the salinity inside the Tampa Bay,along with decreases of horizontal and vertical salt gradients.Subsequently,the salt balance principles are detailed addressed.The primary salt balance is between the total（horizontal plus vertical）advective salt flux divergence and vertical diffusive salt flux divergence except at the channel bottom where horizontal diffusive salt flux divergence comes into play.At last,the salt balance variation induced by winds is further addressed.Wind forcing does not change the relative importance of salt balance terms.The variations of the salt balance terms influenced by winds are highly dependent on the specific locations.Besides,the variations of the total advective salt flux divergence and the vertical diffusive salt flux divergence are nearly couterbalance,and both of two terms are much greater than that of the horizontal diffusive salt flux divergence.
基金The National Natural Science Foundation of China under contract No.41076003the Youth Science and Technology Foundation of East China Sea Branch,SOA under contract Nos 201314 and 201203the open fund of State Key Laboratory of Satellite Ocean Environment Dynamics under Contract No.SOED1402
文摘Results of the Ocean General Circulation Model for the Earth Simulator（OFES） from January 1977 to December2006 are used to investigate mesoscale eddies near the Ryukyu Islands. The results show that：（1） Larger eddies are mainly east of Taiwan, above the Ryukyu Trench and south of the Shikoku Island. These three sea areas are all in the vicinity of the Ryukyu Current.（2） Eddies in the area of the Ryukyu Current are mainly anticyclonic, and conducive to that current. The transport of water east of the Ryukyu Islands is mainly toward the northeast.（3）The Ryukyu Current is significantly affected by the eddies. The lower the latitude, the greater these effects.However, the Kuroshio is relatively stable, and the effect of mesoscale eddies is not significant.（4） A warm eddy south of the Shikoku Island break away from the Kuroshio and move southwest, and is clearly affected by the Ryukyu Current and Kuroshio. Relationships between the mesoscale eddies, Kuroshio meanders, and Ryukyu Current are discussed.
