Results of drag coefficient（CD） from field observations and laboratory wave tank experiments indicate that the operational wave model can overestimate wind energy input under high wind conditions. The wind-wave inte...Results of drag coefficient（CD） from field observations and laboratory wave tank experiments indicate that the operational wave model can overestimate wind energy input under high wind conditions. The wind-wave interaction source term in WAVEWATCH Ⅲ has been modified to examine its behavior with tropical cyclone wind forcing. Using high resolution wind input,numerical experiments under idealized wind field and tropical cyclone Bonnie（1998） were designed to evaluate performance of the modified models. Both experiments indicate that the modified models with reduced CD significantly decrease wind energy input into the wave model and then simulate lower significant wave height（SWH） than the original model. However,the effects on spatial distribution of SWH,mean wavelength,mean wave direction,and directional wave spectra are insignificant. Due to the reduced wind energy input,the idealized experiment shows that the modified models simulate lower SWH than the original model in all four quadrants. The decrease in the front quadrants is significantly larger than that in the rear quadrants;it is larger under higher winds than lower winds. The realistic experiment on tropical cyclone Bonnie shows that the modified model with the various downward trends of CD in high winds creates a simulation that agrees best with scanning radar altimeter observations.展开更多
Wave climate analysis and other applications for the Pacific Ocean require a reliable wave hindcast. Five source and sink term packages in the Wavewatch III model （v3.14 and v4.18） are compared and assessed in this ...Wave climate analysis and other applications for the Pacific Ocean require a reliable wave hindcast. Five source and sink term packages in the Wavewatch III model （v3.14 and v4.18） are compared and assessed in this study through comprehensive observations, including altimeter significant wave height, advanced synthetic aperture radar swell, and buoy wave parameters and spectrum. In addition to the evaluation of typically used integral parameters, the spectra partitioning method contributes to the detailed wave system and wave maturity validation. The modified performance evaluation method （PS） effectively reduces attribute numbers and facilitates the overall assessment. To avoid possible misleading results in the root mean square error-based validations, another indicator called HH （indicating the two authors） is also calculated to guarantee the consistency of the results. The widely used Tolman and Chalikov （TC） package is still generally efficient in determining the integral properties of wave spectra but is physically deficient in explaining the dissipation processes. The ST4 package performs well in overall wave parameters and significantly improves the accuracy of wave systems in the open ocean. Meanwhile, the newly published ST6 package is slightly better in determining swell energy variations. The two packages （ACC350 and BIA） obtained from Wavewatch III v3.14 exhibit large scatters at different sea states. The three most ideal packages are further examined in terms of reproducing wave- induced momentum flux from the perspective of transport. Stokes transport analysis indicates that ST4 is the closest to the NDBC-buoy-spectrum-based transport values, and TC and ST6 tend to overestimate and underestimate the transport magnitude, respectively, in swell mixed areas. This difference must be considered, particularly in air-wave-current coupling research and upper ocean analysis. The assessment results provide guidance for the selection of ST4 for use in a background Pacific Ocean hindcast for high wave climate research and China Sea swell type analysis.展开更多
A WAVEWATCH III version 3.14（WW3） wave model is used to evaluate input/dissipation source term packages WAM3, WAM4 and TC96 considering the effect of atmospheric instability. The comparisons of a significant wave he...A WAVEWATCH III version 3.14（WW3） wave model is used to evaluate input/dissipation source term packages WAM3, WAM4 and TC96 considering the effect of atmospheric instability. The comparisons of a significant wave height acquired from the model with different packages have been performed based on wave observation radar and HY-2 altimetry significant wave height data through five experiments in the South China Sea domain spanning latitudes of 0°–35°N and longitudes of 100°–135°E. The sensitivity of the wind speed correction parameter in the TC96 package also has been analyzed. From the results, the model is unable to dissipate the wave energy efficiently during a swell propagation with either source packages. It is found that TC96 formulation with the ＂effective wind speed＂ strategy performs better than WAM3 and WAM4 formulations. The wind speed correction parameter in the TC96 source package is very sensitive and needs to be calibrated and selected before the WW3 model can be applied to a specific region.展开更多
A bstrac t In this paper,we propose a parallel data assimilation module based on ensemble optimal interpolation(En OI). We embedded the method into the full-spectral third-generation wind-wave model,WAVEWATCH III Vers...A bstrac t In this paper,we propose a parallel data assimilation module based on ensemble optimal interpolation(En OI). We embedded the method into the full-spectral third-generation wind-wave model,WAVEWATCH III Version 3.14,producing a wave data assimilation system. We present our preliminary experiments assimilating altimeter significant wave heights(SWH) using the En OI-based wave assimilation system. Waters north of 15°S in the Indian Ocean and South China Sea were chosen as the target computational domain,which was two-way nested into the global implementation of the WAVEWATCH III. The wave model was forced by six-hourly ocean surface wind velocities from the cross-calibrated multi-platform wind vector dataset. The assimilation used along-track SWH data from the Jason-2 altimeter. We evaluated the effect of the assimilation on the analyses and hindcasts,and found that our technique was effective. Although there was a considerable mean bias in the control SWHs,a month-long consecutive assimilation reduced the bias by approximately 84% and the root mean-square error(RMSE) by approximately 65%. Improvements in the SWH RMSE for both the analysis and hindcast periods were more significant in July than January,because of the monsoon climate. The improvement in model skill persisted for up to 48 h in July. Furthermore,the SWH data assimilation had the greatest impact in areas and seasons where and when the sea-states were dominated by swells.展开更多
目的:探讨全髋关节置换术的CroweⅢ-Ⅳ型发育性髋关节发育不良(developmental dysplasia of the hip,DDH)患者的满意度及造成不满意的相关因素。方法:回顾性分析2013年3月至2018年3月行全髋关节置换术的169例CroweⅢ-Ⅳ型DDH患者,通过...目的:探讨全髋关节置换术的CroweⅢ-Ⅳ型发育性髋关节发育不良(developmental dysplasia of the hip,DDH)患者的满意度及造成不满意的相关因素。方法:回顾性分析2013年3月至2018年3月行全髋关节置换术的169例CroweⅢ-Ⅳ型DDH患者,通过微信进行调查问卷,调查患者对手术总体满意度、10项日常功能满意度和患者认为对自己日常生活影响比较大的前5个问题。手术前后采用髋关节Harris评分进行功能评价。结果:收到完整调查问卷145份,所有患者获随访,时间1~5(3.23±1.22)年。145例患者分成两组,其中对手术疗效满意的118例,不满意的27例,手术总体满意率81.38%(118/145)。患者认为对生活影响比较大的前5个问题分别是术后髋部疼痛,肢体明显不等长、行走、上下楼梯、蹲起。两组术前Harris评分比较,差异无统计学意义(P>0.05),不满意组术后Harris评分较低。术后髋关节疼痛、肢体不等长是影响手术不满意的直接因素。结论:采用全髋关节置换术治疗CroweⅢ-Ⅳ型DDH患者手术难度大;术后髋关节疼痛(轻度以上),肢体不等长(>2 cm)是术后不满意的独立危险因素。展开更多
基金The National Natural Science Foundation of China under contract No. 40706008the Open Research Program of the Key Laboratory of Chinese Acadeing of Sciences for Tropical Marine Environmental Dynamics under contract No. LED0606+1 种基金the Shandong Province Natural Science Foundation of China under contract No. Z2008E02the National High Technology Research and Development Program ("863" Program) of China under contract No. 2008AA09A402
文摘Results of drag coefficient（CD） from field observations and laboratory wave tank experiments indicate that the operational wave model can overestimate wind energy input under high wind conditions. The wind-wave interaction source term in WAVEWATCH Ⅲ has been modified to examine its behavior with tropical cyclone wind forcing. Using high resolution wind input,numerical experiments under idealized wind field and tropical cyclone Bonnie（1998） were designed to evaluate performance of the modified models. Both experiments indicate that the modified models with reduced CD significantly decrease wind energy input into the wave model and then simulate lower significant wave height（SWH） than the original model. However,the effects on spatial distribution of SWH,mean wavelength,mean wave direction,and directional wave spectra are insignificant. Due to the reduced wind energy input,the idealized experiment shows that the modified models simulate lower SWH than the original model in all four quadrants. The decrease in the front quadrants is significantly larger than that in the rear quadrants;it is larger under higher winds than lower winds. The realistic experiment on tropical cyclone Bonnie shows that the modified model with the various downward trends of CD in high winds creates a simulation that agrees best with scanning radar altimeter observations.
基金The National High Technology Research and Development Program(863 Program) of China under contract No.2013AA122803the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11010104
文摘Wave climate analysis and other applications for the Pacific Ocean require a reliable wave hindcast. Five source and sink term packages in the Wavewatch III model （v3.14 and v4.18） are compared and assessed in this study through comprehensive observations, including altimeter significant wave height, advanced synthetic aperture radar swell, and buoy wave parameters and spectrum. In addition to the evaluation of typically used integral parameters, the spectra partitioning method contributes to the detailed wave system and wave maturity validation. The modified performance evaluation method （PS） effectively reduces attribute numbers and facilitates the overall assessment. To avoid possible misleading results in the root mean square error-based validations, another indicator called HH （indicating the two authors） is also calculated to guarantee the consistency of the results. The widely used Tolman and Chalikov （TC） package is still generally efficient in determining the integral properties of wave spectra but is physically deficient in explaining the dissipation processes. The ST4 package performs well in overall wave parameters and significantly improves the accuracy of wave systems in the open ocean. Meanwhile, the newly published ST6 package is slightly better in determining swell energy variations. The two packages （ACC350 and BIA） obtained from Wavewatch III v3.14 exhibit large scatters at different sea states. The three most ideal packages are further examined in terms of reproducing wave- induced momentum flux from the perspective of transport. Stokes transport analysis indicates that ST4 is the closest to the NDBC-buoy-spectrum-based transport values, and TC and ST6 tend to overestimate and underestimate the transport magnitude, respectively, in swell mixed areas. This difference must be considered, particularly in air-wave-current coupling research and upper ocean analysis. The assessment results provide guidance for the selection of ST4 for use in a background Pacific Ocean hindcast for high wave climate research and China Sea swell type analysis.
基金The National Natural Science Foundation of China under contract No.41406007the National Key Research and Development Project of China under contract No.2016YFC1401800+1 种基金the National Natural Science Foundation of China under contract No.41306002the Fundamental Research Funds for the Central Universities of China under contract Nos 16CX02011A and 15CX08011A
文摘A WAVEWATCH III version 3.14（WW3） wave model is used to evaluate input/dissipation source term packages WAM3, WAM4 and TC96 considering the effect of atmospheric instability. The comparisons of a significant wave height acquired from the model with different packages have been performed based on wave observation radar and HY-2 altimetry significant wave height data through five experiments in the South China Sea domain spanning latitudes of 0°–35°N and longitudes of 100°–135°E. The sensitivity of the wind speed correction parameter in the TC96 package also has been analyzed. From the results, the model is unable to dissipate the wave energy efficiently during a swell propagation with either source packages. It is found that TC96 formulation with the ＂effective wind speed＂ strategy performs better than WAM3 and WAM4 formulations. The wind speed correction parameter in the TC96 source package is very sensitive and needs to be calibrated and selected before the WW3 model can be applied to a specific region.
基金Supported by the National Special Research Fund for Non-Profit Marine Sector(Nos.201005033,201105002)the National High Technology Research and Development Program of China(863 Program)(No.2012AA091801)+1 种基金the National Natural Science Foundation of China(No.U1133001)the NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1406401)
文摘A bstrac t In this paper,we propose a parallel data assimilation module based on ensemble optimal interpolation(En OI). We embedded the method into the full-spectral third-generation wind-wave model,WAVEWATCH III Version 3.14,producing a wave data assimilation system. We present our preliminary experiments assimilating altimeter significant wave heights(SWH) using the En OI-based wave assimilation system. Waters north of 15°S in the Indian Ocean and South China Sea were chosen as the target computational domain,which was two-way nested into the global implementation of the WAVEWATCH III. The wave model was forced by six-hourly ocean surface wind velocities from the cross-calibrated multi-platform wind vector dataset. The assimilation used along-track SWH data from the Jason-2 altimeter. We evaluated the effect of the assimilation on the analyses and hindcasts,and found that our technique was effective. Although there was a considerable mean bias in the control SWHs,a month-long consecutive assimilation reduced the bias by approximately 84% and the root mean-square error(RMSE) by approximately 65%. Improvements in the SWH RMSE for both the analysis and hindcast periods were more significant in July than January,because of the monsoon climate. The improvement in model skill persisted for up to 48 h in July. Furthermore,the SWH data assimilation had the greatest impact in areas and seasons where and when the sea-states were dominated by swells.
文摘目的:探讨全髋关节置换术的CroweⅢ-Ⅳ型发育性髋关节发育不良(developmental dysplasia of the hip,DDH)患者的满意度及造成不满意的相关因素。方法:回顾性分析2013年3月至2018年3月行全髋关节置换术的169例CroweⅢ-Ⅳ型DDH患者,通过微信进行调查问卷,调查患者对手术总体满意度、10项日常功能满意度和患者认为对自己日常生活影响比较大的前5个问题。手术前后采用髋关节Harris评分进行功能评价。结果:收到完整调查问卷145份,所有患者获随访,时间1~5(3.23±1.22)年。145例患者分成两组,其中对手术疗效满意的118例,不满意的27例,手术总体满意率81.38%(118/145)。患者认为对生活影响比较大的前5个问题分别是术后髋部疼痛,肢体明显不等长、行走、上下楼梯、蹲起。两组术前Harris评分比较,差异无统计学意义(P>0.05),不满意组术后Harris评分较低。术后髋关节疼痛、肢体不等长是影响手术不满意的直接因素。结论:采用全髋关节置换术治疗CroweⅢ-Ⅳ型DDH患者手术难度大;术后髋关节疼痛(轻度以上),肢体不等长(>2 cm)是术后不满意的独立危险因素。
