利用1957—2006共50年高分辨率的长时间序列海洋模式OFES(OGCM for the Earth Simulator)数据,对北赤道流(NEC)的分叉规律及其与ENSO循环的关系进行了分析。结果表明:(1)NEC分叉纬度具有明显的季节和年际变化,周期主要呈现为3—6个月的...利用1957—2006共50年高分辨率的长时间序列海洋模式OFES(OGCM for the Earth Simulator)数据,对北赤道流(NEC)的分叉规律及其与ENSO循环的关系进行了分析。结果表明:(1)NEC分叉纬度具有明显的季节和年际变化,周期主要呈现为3—6个月的季节内振荡和2年、2—7年左右ENSO尺度周期振荡以及10年以上的年代际变化。在季节尺度上,分叉位置春季偏南,秋季偏北,并且分叉纬度随深度的增加向北移动,其北移幅度冬季最大,夏季最小。而在年际变化尺度上,NEC分叉纬度具有较强的年际变化信号,与ENSO循环密切相关,El Ni?o年分叉位置偏北,La Ni?a年分叉位置偏南。(2)NEC分叉纬度的变化与北太平洋0—30°N之间的纬向风应力旋度积分零线位置密切相关,零线的南北偏移导致了分叉位置的改变,在不同深度上,零线位置对分叉纬度改变的影响时间不同,表层需1个月,而500 m深度则需4个月左右。(3)NEC分叉影响着黑潮(KC)与(棉兰老流)MC的流量分配率,其年际异常变化与冷、暖ENSO事件发生密切相关,当El Ni?o发生时,KC流量分配率减少,MC流量分配率增加;La Ni?a年情况则相反。展开更多
自黑潮脱落并由吕宋海峡进入中国南海的中尺度涡(简称脱落涡旋)对黑潮与南海的水体交换、热量及物质输送等过程均有十分重要的作用。基于1993—2013年OFES(OGCM for the Earth Simulator)模式数据产品,分析研究了脱落涡旋的统计特征及...自黑潮脱落并由吕宋海峡进入中国南海的中尺度涡(简称脱落涡旋)对黑潮与南海的水体交换、热量及物质输送等过程均有十分重要的作用。基于1993—2013年OFES(OGCM for the Earth Simulator)模式数据产品,分析研究了脱落涡旋的统计特征及其温盐流三维结构,并与卫星观测结果进行对比分析。OFES模式的海表面高度数据和卫星高度计数据的统计结果都表明气旋式脱落涡旋(脱落冷涡)绝大部分在黑潮西侧边缘生成,反气旋式脱落涡旋(脱落暖涡)则大部分在黑潮控制区(包括黑潮流套区)生成,脱落暖涡的数量远多于脱落冷涡的。OFES模式数据得到的脱落涡旋个数和出现频率较卫星观测结果要明显偏低。此外,由OFES模式数据得到的脱落涡旋三维结构表明,黑潮控制区和黑潮西侧边缘生成的脱落冷涡的流场垂向影响深度差异较大,而脱落暖涡的流场垂向影响深度一般达水深1000 m以深,脱落涡旋的位势温度的垂向影响深度与该涡的流场垂向影响深度相当,其盐度的垂向影响深度则较浅;脱落涡旋的温盐结构受黑潮的影响较大。展开更多
An analysis of a 68-year monthly hindcast output from an eddy-resolving ocean general circulation model reveals the relationship between the interannual variability of the Kerama Gap transport(KGT)and the Kuroshio/Ryu...An analysis of a 68-year monthly hindcast output from an eddy-resolving ocean general circulation model reveals the relationship between the interannual variability of the Kerama Gap transport(KGT)and the Kuroshio/Ryukyu Current system.The study found a significant difference in the interannual variability of the upstream and downstream transports of the East China Sea-(ECS-)Kuroshio and the Ryukyu Current.The interannual variability of the KGT was found to be of paramount importance in causing the differences between the upstream and downstream ECS-Kuroshio.Additionally,it contributed approximately 37%to the variability of the Ryukyu Current.The interannual variability of the KGT was well described by a two-layer rotating hydraulic theory.It was dominated by its subsurface-intensified flow core,and the upper layer transport made a weaker negative contribution to the total KGT.The subsurface flow core was found to be mainly driven by the subsurface pressure head across the Kerama Gap,and the pressure head was further dominated by the subsurface density anomalies on the Pacific side.These density anomalies could be traced back to the eastern open ocean,and their propagation speed was estimated to be about 7.4 km/d,which is consistent with the speed of the local first-order baroclinic Rossby wave.When the negative(positive)density anomaly signal reached the southern region of the Kerama Gap,it triggered the increase(decrease)of the KGT towards the Pacific side and the formation of an anticyclonic(cyclonic)vortex by baroclinic adjustment.Meanwhile,there is an increase(decrease)in the upstream transport of the entire Kuroshio/Ryukyu Current system and an offshore flow that decreases(increases)the downstream Ryukyu Current.展开更多
利用高分辨率的长时间序列海洋模式资料OFES(OGCM for the Earth Simulator),对北太平洋低纬度西边界流的时空分布特征及其与ENSO循环的联系进行了初步分析。结果表明:北太平洋低纬度西边界流具有明显的季节和年际变化特征。在季节尺度...利用高分辨率的长时间序列海洋模式资料OFES(OGCM for the Earth Simulator),对北太平洋低纬度西边界流的时空分布特征及其与ENSO循环的联系进行了初步分析。结果表明:北太平洋低纬度西边界流具有明显的季节和年际变化特征。在季节尺度上,整个NMK系统都表现为春强秋弱,而在年际尺度上,NEC和KC主要为2-7年的ENSO周期;MC主要表现为准两年周期振荡。另外,整个NMK系统与ENSO循环密切相关,当ElNio发生时,NMK系统流量增大,流系加强,而当LaNia发生时,NMK系统流量减小,流系变弱。整个过程大约为6-10个季节,是一个准ENSO过程。展开更多
1 The unique ocean forecasting system (OFS) based on FIO-COM The OFS is based on the surface wave-tide-circulation coupled ocean model developed by the First Institute of Oceanography (FIO-COM), Ministry of Natural Re...1 The unique ocean forecasting system (OFS) based on FIO-COM The OFS is based on the surface wave-tide-circulation coupled ocean model developed by the First Institute of Oceanography (FIO-COM), Ministry of Natural Resources, China. The half-century challenge that ocean circulation models must address is that the forecasting/simulated sea surface temperature overheats while the sub-surface temperature is too cold, especially during the summer. Qiao et al.(2004, 2010, 2016) found that the non-breaking surface wave can generate turbulence through wave-turbulence interaction, and they developed the wave-induced mixing theory, which has been confirmed by observations, laboratory experiments and model numerical simulations. As validated by ocean circulation models from various research groups, including Geophysical Fluid Dynamics Laboratory (GFDL) in the US (Fan and Griffies, 2014), Uppsala University of Sweden (Wu et al., 2015), Laboratoire d’Etudes en Geophysique et Oceanographie Spatiale (LEGOS) in France (Malek and Babanin, 2014), Budapest University of Technology and Economics in Hungary (Peter and Kramer, 2016) and the Ocean University of China (Lin et al., 2006), the non-breaking surface waveinduced vertical mixing (Bv) can always dramatically improve the simulation capacity of various ocean circulation models. The First Institute of Oceanography (FIO) research group found that tidal-induced mixing plays a key role in the formation of coastal upwelling, in the bottom mixed layer and in areas with sea mounts (Lv et al., 2006, 2008). With the above breakthroughs, the first surface wavetide-circulation coupled model of FIO-COM was developed in 2013. It was adopted to produce a reanalysis dataset for the period of January 2014 to April 2016, and it has been used for the operational OFS since May 2016. A highly efficient parallel scheme was designed to use the full capacity of Taihu Light with 10 649 600 CPU cores (Qiao et al., 2016), which earned a finalist nomination for the international Association for Computing Machinery (ACM) Gordon Bell Prize.展开更多
Two complex properties, varying time-delay and block-oriented nonlinearity, are very common in chemical engineering processes and not easy to be controlled by routine control methods. Aimed at these two complex proper...Two complex properties, varying time-delay and block-oriented nonlinearity, are very common in chemical engineering processes and not easy to be controlled by routine control methods. Aimed at these two complex properties, a novel adaptive control algorithm the basis of nonlinear OFS （orthonormal functional series） model is proposed. First, the hybrid model which combines OFS and Volterra series is introduced. Then, a stable state feedback strategy is used to construct a nonlinear adaptive control algorithm that can guarantee the closed-loop stability and can track the set point curve without steady-state errors. Finally, control simulations and experiments on a nonlinear process with varying time-delay are presented. A number of experimental results validate the efficiency and superiority of this algorithm.展开更多
文摘利用1957—2006共50年高分辨率的长时间序列海洋模式OFES(OGCM for the Earth Simulator)数据,对北赤道流(NEC)的分叉规律及其与ENSO循环的关系进行了分析。结果表明:(1)NEC分叉纬度具有明显的季节和年际变化,周期主要呈现为3—6个月的季节内振荡和2年、2—7年左右ENSO尺度周期振荡以及10年以上的年代际变化。在季节尺度上,分叉位置春季偏南,秋季偏北,并且分叉纬度随深度的增加向北移动,其北移幅度冬季最大,夏季最小。而在年际变化尺度上,NEC分叉纬度具有较强的年际变化信号,与ENSO循环密切相关,El Ni?o年分叉位置偏北,La Ni?a年分叉位置偏南。(2)NEC分叉纬度的变化与北太平洋0—30°N之间的纬向风应力旋度积分零线位置密切相关,零线的南北偏移导致了分叉位置的改变,在不同深度上,零线位置对分叉纬度改变的影响时间不同,表层需1个月,而500 m深度则需4个月左右。(3)NEC分叉影响着黑潮(KC)与(棉兰老流)MC的流量分配率,其年际异常变化与冷、暖ENSO事件发生密切相关,当El Ni?o发生时,KC流量分配率减少,MC流量分配率增加;La Ni?a年情况则相反。
文摘自黑潮脱落并由吕宋海峡进入中国南海的中尺度涡(简称脱落涡旋)对黑潮与南海的水体交换、热量及物质输送等过程均有十分重要的作用。基于1993—2013年OFES(OGCM for the Earth Simulator)模式数据产品,分析研究了脱落涡旋的统计特征及其温盐流三维结构,并与卫星观测结果进行对比分析。OFES模式的海表面高度数据和卫星高度计数据的统计结果都表明气旋式脱落涡旋(脱落冷涡)绝大部分在黑潮西侧边缘生成,反气旋式脱落涡旋(脱落暖涡)则大部分在黑潮控制区(包括黑潮流套区)生成,脱落暖涡的数量远多于脱落冷涡的。OFES模式数据得到的脱落涡旋个数和出现频率较卫星观测结果要明显偏低。此外,由OFES模式数据得到的脱落涡旋三维结构表明,黑潮控制区和黑潮西侧边缘生成的脱落冷涡的流场垂向影响深度差异较大,而脱落暖涡的流场垂向影响深度一般达水深1000 m以深,脱落涡旋的位势温度的垂向影响深度与该涡的流场垂向影响深度相当,其盐度的垂向影响深度则较浅;脱落涡旋的温盐结构受黑潮的影响较大。
基金The Fundamental Research Funds for the Central Universities under contract No.B220201024.
文摘An analysis of a 68-year monthly hindcast output from an eddy-resolving ocean general circulation model reveals the relationship between the interannual variability of the Kerama Gap transport(KGT)and the Kuroshio/Ryukyu Current system.The study found a significant difference in the interannual variability of the upstream and downstream transports of the East China Sea-(ECS-)Kuroshio and the Ryukyu Current.The interannual variability of the KGT was found to be of paramount importance in causing the differences between the upstream and downstream ECS-Kuroshio.Additionally,it contributed approximately 37%to the variability of the Ryukyu Current.The interannual variability of the KGT was well described by a two-layer rotating hydraulic theory.It was dominated by its subsurface-intensified flow core,and the upper layer transport made a weaker negative contribution to the total KGT.The subsurface flow core was found to be mainly driven by the subsurface pressure head across the Kerama Gap,and the pressure head was further dominated by the subsurface density anomalies on the Pacific side.These density anomalies could be traced back to the eastern open ocean,and their propagation speed was estimated to be about 7.4 km/d,which is consistent with the speed of the local first-order baroclinic Rossby wave.When the negative(positive)density anomaly signal reached the southern region of the Kerama Gap,it triggered the increase(decrease)of the KGT towards the Pacific side and the formation of an anticyclonic(cyclonic)vortex by baroclinic adjustment.Meanwhile,there is an increase(decrease)in the upstream transport of the entire Kuroshio/Ryukyu Current system and an offshore flow that decreases(increases)the downstream Ryukyu Current.
文摘利用高分辨率的长时间序列海洋模式资料OFES(OGCM for the Earth Simulator),对北太平洋低纬度西边界流的时空分布特征及其与ENSO循环的联系进行了初步分析。结果表明:北太平洋低纬度西边界流具有明显的季节和年际变化特征。在季节尺度上,整个NMK系统都表现为春强秋弱,而在年际尺度上,NEC和KC主要为2-7年的ENSO周期;MC主要表现为准两年周期振荡。另外,整个NMK系统与ENSO循环密切相关,当ElNio发生时,NMK系统流量增大,流系加强,而当LaNia发生时,NMK系统流量减小,流系变弱。整个过程大约为6-10个季节,是一个准ENSO过程。
基金The National Natural Science Foundation of China under contract No.41821004the NSFC-Shandong Joint Fund for Marine Science Research Centers under contract No.U1606405+1 种基金the International Cooperation Project of Indo-Pacific Ocean Environment Variation and Air-Sea Interaction under contract No.GASI-IPOVAI-05the IOC/WESTPAC OFS Project
文摘1 The unique ocean forecasting system (OFS) based on FIO-COM The OFS is based on the surface wave-tide-circulation coupled ocean model developed by the First Institute of Oceanography (FIO-COM), Ministry of Natural Resources, China. The half-century challenge that ocean circulation models must address is that the forecasting/simulated sea surface temperature overheats while the sub-surface temperature is too cold, especially during the summer. Qiao et al.(2004, 2010, 2016) found that the non-breaking surface wave can generate turbulence through wave-turbulence interaction, and they developed the wave-induced mixing theory, which has been confirmed by observations, laboratory experiments and model numerical simulations. As validated by ocean circulation models from various research groups, including Geophysical Fluid Dynamics Laboratory (GFDL) in the US (Fan and Griffies, 2014), Uppsala University of Sweden (Wu et al., 2015), Laboratoire d’Etudes en Geophysique et Oceanographie Spatiale (LEGOS) in France (Malek and Babanin, 2014), Budapest University of Technology and Economics in Hungary (Peter and Kramer, 2016) and the Ocean University of China (Lin et al., 2006), the non-breaking surface waveinduced vertical mixing (Bv) can always dramatically improve the simulation capacity of various ocean circulation models. The First Institute of Oceanography (FIO) research group found that tidal-induced mixing plays a key role in the formation of coastal upwelling, in the bottom mixed layer and in areas with sea mounts (Lv et al., 2006, 2008). With the above breakthroughs, the first surface wavetide-circulation coupled model of FIO-COM was developed in 2013. It was adopted to produce a reanalysis dataset for the period of January 2014 to April 2016, and it has been used for the operational OFS since May 2016. A highly efficient parallel scheme was designed to use the full capacity of Taihu Light with 10 649 600 CPU cores (Qiao et al., 2016), which earned a finalist nomination for the international Association for Computing Machinery (ACM) Gordon Bell Prize.
文摘Two complex properties, varying time-delay and block-oriented nonlinearity, are very common in chemical engineering processes and not easy to be controlled by routine control methods. Aimed at these two complex properties, a novel adaptive control algorithm the basis of nonlinear OFS （orthonormal functional series） model is proposed. First, the hybrid model which combines OFS and Volterra series is introduced. Then, a stable state feedback strategy is used to construct a nonlinear adaptive control algorithm that can guarantee the closed-loop stability and can track the set point curve without steady-state errors. Finally, control simulations and experiments on a nonlinear process with varying time-delay are presented. A number of experimental results validate the efficiency and superiority of this algorithm.
