基于福建省冬半年沿海和港湾岛屿自动站的逐时极大风观测资料和WRF(Weather Research and Forecast)、EC(European Centre for Medium-Range Weather Forecasts)细网格以及T639(TL639L60)三种模式预报的10 m风场资料,将模式预报...基于福建省冬半年沿海和港湾岛屿自动站的逐时极大风观测资料和WRF(Weather Research and Forecast)、EC(European Centre for Medium-Range Weather Forecasts)细网格以及T639(TL639L60)三种模式预报的10 m风场资料,将模式预报的风向风速与观测资料进行对比检验,结果表明:福建省沿海冬半年大风的盛行风向以东北风为主,大风的时空分布极为不均,沿海风力的脉动性、跳跃性、局地性突出。从三种模式对风速风向的模拟效果来看, WRF和EC细网格的预报效果较好,有可参考性, T639可参考性不高。对于风速,模式预报结果相比实况极大风速偏小,港湾岛屿代表站风速的平均绝对误差均小于沿海代表站,预报平均误差由沿海向内陆逐渐减小,由中部向南北逐渐减小。风向相比风速的预报效果要差, WRF和EC细网格的风向预报误差在45°-50°,有一定的参考意义;港湾岛屿代表站风向的平均绝对误差大于沿海代表站,以浮标站的误差最大。当观测风速出现7级及以上风速时,若对大风进行分级检验,则较低风速的预报平均绝对误差小于较高风速;风向预报的平均绝对误差也大大降低,且误差都在45°以内,具有良好的参考性。展开更多
In this study, a 47-day regional climate simulation of the heavy rainfall in the Yangtze-Huai River Basin during the summer of 2003 was conducted using the Weather Research and Forecast (WRY) model. The simulation r...In this study, a 47-day regional climate simulation of the heavy rainfall in the Yangtze-Huai River Basin during the summer of 2003 was conducted using the Weather Research and Forecast (WRY) model. The simulation reproduces reasonably well the evolution of the rainfall during the study period's three successive rainy phases, especially the frequent heavy rainfall events occurring in the Huai River Basin. The model captures the major rainfall peak observed by the monitoring stations in the morning. Another peak appears later than that shown by the observations. In addition, the simulation realistically captures not only the evolution of the low-level winds but also the characteristics of their diurnal variation. The strong southwesterly (low-level jet, LLJ) wind speed increases beginning in the early evening and reaches a peak in the morning; it then gradually decreases until the afternoon. The intense LLJ forms a strong convergent circulation pattern in the early morning along the Yangtze-Huai River Basin. This pattern partly explains the rainfall peak observed at this time. This study furnishes a basis for the further analysis of the mechanisms of evolution of the LLJ and for the further study of the interactions between the LLJ and rainfall.展开更多
文摘基于福建省冬半年沿海和港湾岛屿自动站的逐时极大风观测资料和WRF(Weather Research and Forecast)、EC(European Centre for Medium-Range Weather Forecasts)细网格以及T639(TL639L60)三种模式预报的10 m风场资料,将模式预报的风向风速与观测资料进行对比检验,结果表明:福建省沿海冬半年大风的盛行风向以东北风为主,大风的时空分布极为不均,沿海风力的脉动性、跳跃性、局地性突出。从三种模式对风速风向的模拟效果来看, WRF和EC细网格的预报效果较好,有可参考性, T639可参考性不高。对于风速,模式预报结果相比实况极大风速偏小,港湾岛屿代表站风速的平均绝对误差均小于沿海代表站,预报平均误差由沿海向内陆逐渐减小,由中部向南北逐渐减小。风向相比风速的预报效果要差, WRF和EC细网格的风向预报误差在45°-50°,有一定的参考意义;港湾岛屿代表站风向的平均绝对误差大于沿海代表站,以浮标站的误差最大。当观测风速出现7级及以上风速时,若对大风进行分级检验,则较低风速的预报平均绝对误差小于较高风速;风向预报的平均绝对误差也大大降低,且误差都在45°以内,具有良好的参考性。
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-Q11-04)the National High Technology Research and Development Program of China (863 Program, Grant No. 2010AA012304)+2 种基金the National Natural Science Foundation of China (Grant No. 40905049)the LASG State Key Laboratory special fundthe LASG free exploration fund
文摘In this study, a 47-day regional climate simulation of the heavy rainfall in the Yangtze-Huai River Basin during the summer of 2003 was conducted using the Weather Research and Forecast (WRY) model. The simulation reproduces reasonably well the evolution of the rainfall during the study period's three successive rainy phases, especially the frequent heavy rainfall events occurring in the Huai River Basin. The model captures the major rainfall peak observed by the monitoring stations in the morning. Another peak appears later than that shown by the observations. In addition, the simulation realistically captures not only the evolution of the low-level winds but also the characteristics of their diurnal variation. The strong southwesterly (low-level jet, LLJ) wind speed increases beginning in the early evening and reaches a peak in the morning; it then gradually decreases until the afternoon. The intense LLJ forms a strong convergent circulation pattern in the early morning along the Yangtze-Huai River Basin. This pattern partly explains the rainfall peak observed at this time. This study furnishes a basis for the further analysis of the mechanisms of evolution of the LLJ and for the further study of the interactions between the LLJ and rainfall.