This paper proposes a new method for data assimilation of the surface radial current observed by High Frequency ground wave radar and optimization of the bottom friction coefficient.In this method,the shallow water wa...This paper proposes a new method for data assimilation of the surface radial current observed by High Frequency ground wave radar and optimization of the bottom friction coefficient.In this method,the shallow water wave equation is introduced into the cost function of the multigrid three-dimensional variation data assimilation method as the weak constraint term,the surface current and the bottom friction coefficient are defined as the analytical variables,and the high spatiotemporal resolution surface radial flow observed by the high-frequency ground wave radar is used to optimize the surface current and bottom friction coefficient.This method can effectively consider the spatiotemporal correlation of radar data and extract multiscale information from surface radial flow data from long waves to short waves.Introducing the shallow water wave equation into the cost function as a weak constraint condition can adjust both the momentum and mass fields simultaneously to obtain more reasonable analysis information.The optimized bottom friction coefficient is introduced into the regional ocean numerical model to carry out numerical experiments.The test results show that the bottom friction coefficient obtained by this method can effectively improve the accuracy of the numerical simulation of sea surface height in the offshore area and reduce the simulation error.展开更多
目的探讨3D打印技术在小儿后天性肘内翻畸形截骨矫形术中的临床应用价值。方法收集2016年6月至2018年8月由重庆大学附属三峡医院小儿外科收治的16例肘内翻畸形患者作为研究对象,均行截骨矫形手术治疗。其中男童10例,女童6例,平均年龄7....目的探讨3D打印技术在小儿后天性肘内翻畸形截骨矫形术中的临床应用价值。方法收集2016年6月至2018年8月由重庆大学附属三峡医院小儿外科收治的16例肘内翻畸形患者作为研究对象,均行截骨矫形手术治疗。其中男童10例,女童6例,平均年龄7.7岁。术前根据HSS(Hospital for Special Surgery)肘关节评分标准评价肘关节功能,行肘关节CT扫描,建立数字模型,按照1∶1等比例打印3D实体模型,在模型上设计截骨平面,术中参照3D模型实施截骨矫形。手术后6个月复查,采用HSS肘关节评分标准评价肘关节功能,拍摄肘关节正侧位X线片测量肘关节提携角、肱骨前倾角和鲍曼角,并与术前设计进行比较,评价矫形效果是否符合预期。结果16例患者均在全麻下顺利完成手术,术后均获随访,所有患者获骨性愈合,肘内翻畸形获得矫正,无神经血管损伤、术区感染、克氏针移位等并发症发生。3D模型模拟手术效果:提携角范围为9°~19°,平均(13.57±2.62)°;手术后6个月X线片结果:提携角范围为9°~19°,平均(14.34±3.28)°,前倾角范围为24°~51°,平均为(40.08±7.44)°,鲍曼角范围为55°~76°,平均为(67.54±6.10)°。3D模拟手术与实际手术后提携角对比,差异无统计学意义(t=1.76,P=0.1)。术后6个月随访时肘关节功能评定:优10例,良0例,一般5例,差1例。肘关节功能评分:69~100分,平均(89.00±11.62)分;与术前肘关节功能评分比较,差异无统计学意义(t=1.03,P=0.32)。结论在小儿肘关节畸形截骨矫形术中运用3D打印技术,有助于评估畸形形态和精确设计截骨角度,截骨矫形效果符合预期。展开更多
Since QuikSCAT is available in cloudy and rainy condition, its wind data are valuable in monitoring and real time forecasting the wind field, especially in sparse genesis regions of tropical cyclones. In order to unde...Since QuikSCAT is available in cloudy and rainy condition, its wind data are valuable in monitoring and real time forecasting the wind field, especially in sparse genesis regions of tropical cyclones. In order to understand and investigate the impact of QuikSCAT wind data, the three-dimensional variational data assimilation (3D-VAR) of scatterometric wind data has been employed for the tropical cyclone 'Vongfong' in the year 2002. The result shows that the QuikSCAT wind data have positive impact on the analysis and forecasting. But the positive impact is slight. The present results suggest that how to assimilate QuikSCAT wind data effectively is important and will be a challenge to meteorologists.展开更多
An approach to assimilate Doppler radar radial winds into a high resolution Numerical Weather Prediction (NWP) model using 3D-Var system is described. We discuss the types of errors that occur in radar radial winds. S...An approach to assimilate Doppler radar radial winds into a high resolution Numerical Weather Prediction (NWP) model using 3D-Var system is described. We discuss the types of errors that occur in radar radial winds. Some related problems such as nonlinearity and sensitivity of the forecast to possible small errors in initial conditions, random observation errors, and the background states are also considered. The technique can be used to improve the model forecasts, in the Gulf area, at the local scale and under high aerosol (dust/sand/pollution) conditions.展开更多
To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining an ocean circulation model based on the Regional ...To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining an ocean circulation model based on the Regional Ocean Modeling System (ROMS) with three-dimensional variational analysis schemes. This system, which is called FRA-ROMS, is a basic and essential tool for the systematic conduct of fisheries science. The main aim of FRA-ROMS is to realistically simulate mesoscale variations over the Kuroshio-Oyashio region. Here, in situ oceanographic and satellite data were assimilated into FRA-ROMS using a weekly time window. We first examined the reproducibility through comparison with several oceanographic datasets with an Eulerian reference frame. FRA-ROMS was able to reproduce representative features of mesoscale variations such as the position of the Kuroshio path, variability of the Kuroshio Extension, and southward intrusions of the Oyashio. Second, using a Lagrangian reference frame, we estimated position errors between ocean drifters and particles passively transported by simulated currents, because particle tracking is an essential technique used in applications of reanalysis products to fisheries science. Finally, we summarize recent and ongoing fisheries studies that use FRA-ROMS and mention several new developments and enhancements that will be implemented in the near future.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 41506039, 41776004, 41775100 and 41606039)the National Key Research and Development Program of China (No. 2016YFC1401800)+1 种基金the Fundamental Research Funds for the Central Universities (No. 2016B12514)the National Programme on Global Change and Air-Sea Interaction of China (No. GASI-IPO VAI-04)
文摘This paper proposes a new method for data assimilation of the surface radial current observed by High Frequency ground wave radar and optimization of the bottom friction coefficient.In this method,the shallow water wave equation is introduced into the cost function of the multigrid three-dimensional variation data assimilation method as the weak constraint term,the surface current and the bottom friction coefficient are defined as the analytical variables,and the high spatiotemporal resolution surface radial flow observed by the high-frequency ground wave radar is used to optimize the surface current and bottom friction coefficient.This method can effectively consider the spatiotemporal correlation of radar data and extract multiscale information from surface radial flow data from long waves to short waves.Introducing the shallow water wave equation into the cost function as a weak constraint condition can adjust both the momentum and mass fields simultaneously to obtain more reasonable analysis information.The optimized bottom friction coefficient is introduced into the regional ocean numerical model to carry out numerical experiments.The test results show that the bottom friction coefficient obtained by this method can effectively improve the accuracy of the numerical simulation of sea surface height in the offshore area and reduce the simulation error.
文摘目的探讨3D打印技术在小儿后天性肘内翻畸形截骨矫形术中的临床应用价值。方法收集2016年6月至2018年8月由重庆大学附属三峡医院小儿外科收治的16例肘内翻畸形患者作为研究对象,均行截骨矫形手术治疗。其中男童10例,女童6例,平均年龄7.7岁。术前根据HSS(Hospital for Special Surgery)肘关节评分标准评价肘关节功能,行肘关节CT扫描,建立数字模型,按照1∶1等比例打印3D实体模型,在模型上设计截骨平面,术中参照3D模型实施截骨矫形。手术后6个月复查,采用HSS肘关节评分标准评价肘关节功能,拍摄肘关节正侧位X线片测量肘关节提携角、肱骨前倾角和鲍曼角,并与术前设计进行比较,评价矫形效果是否符合预期。结果16例患者均在全麻下顺利完成手术,术后均获随访,所有患者获骨性愈合,肘内翻畸形获得矫正,无神经血管损伤、术区感染、克氏针移位等并发症发生。3D模型模拟手术效果:提携角范围为9°~19°,平均(13.57±2.62)°;手术后6个月X线片结果:提携角范围为9°~19°,平均(14.34±3.28)°,前倾角范围为24°~51°,平均为(40.08±7.44)°,鲍曼角范围为55°~76°,平均为(67.54±6.10)°。3D模拟手术与实际手术后提携角对比,差异无统计学意义(t=1.76,P=0.1)。术后6个月随访时肘关节功能评定:优10例,良0例,一般5例,差1例。肘关节功能评分:69~100分,平均(89.00±11.62)分;与术前肘关节功能评分比较,差异无统计学意义(t=1.03,P=0.32)。结论在小儿肘关节畸形截骨矫形术中运用3D打印技术,有助于评估畸形形态和精确设计截骨角度,截骨矫形效果符合预期。
文摘Since QuikSCAT is available in cloudy and rainy condition, its wind data are valuable in monitoring and real time forecasting the wind field, especially in sparse genesis regions of tropical cyclones. In order to understand and investigate the impact of QuikSCAT wind data, the three-dimensional variational data assimilation (3D-VAR) of scatterometric wind data has been employed for the tropical cyclone 'Vongfong' in the year 2002. The result shows that the QuikSCAT wind data have positive impact on the analysis and forecasting. But the positive impact is slight. The present results suggest that how to assimilate QuikSCAT wind data effectively is important and will be a challenge to meteorologists.
文摘An approach to assimilate Doppler radar radial winds into a high resolution Numerical Weather Prediction (NWP) model using 3D-Var system is described. We discuss the types of errors that occur in radar radial winds. Some related problems such as nonlinearity and sensitivity of the forecast to possible small errors in initial conditions, random observation errors, and the background states are also considered. The technique can be used to improve the model forecasts, in the Gulf area, at the local scale and under high aerosol (dust/sand/pollution) conditions.
基金Key Scientific Research Project of Guangdong (2004B32601002)Promotion Project forLatest Meteorological Technology (CMATG2005M17)+1 种基金National Project No.973 (2004CB18307)"Research onAssimilation Techniques for Tropics based on Modern Observation Technologies"
文摘To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining an ocean circulation model based on the Regional Ocean Modeling System (ROMS) with three-dimensional variational analysis schemes. This system, which is called FRA-ROMS, is a basic and essential tool for the systematic conduct of fisheries science. The main aim of FRA-ROMS is to realistically simulate mesoscale variations over the Kuroshio-Oyashio region. Here, in situ oceanographic and satellite data were assimilated into FRA-ROMS using a weekly time window. We first examined the reproducibility through comparison with several oceanographic datasets with an Eulerian reference frame. FRA-ROMS was able to reproduce representative features of mesoscale variations such as the position of the Kuroshio path, variability of the Kuroshio Extension, and southward intrusions of the Oyashio. Second, using a Lagrangian reference frame, we estimated position errors between ocean drifters and particles passively transported by simulated currents, because particle tracking is an essential technique used in applications of reanalysis products to fisheries science. Finally, we summarize recent and ongoing fisheries studies that use FRA-ROMS and mention several new developments and enhancements that will be implemented in the near future.
