CAJ | 학술논문

中国国家气象中心基于全球数值模式、采用人造bogus涡旋初始化方案建立起来的台风数值预报业务系统是独立于全球资料分析同化-预报循环过程来运行的.实际上,台风涡旋是全球数值预报中一个重要的、密不可分的中尺度系统,台风的正确描述会对周围的大尺度形势预报产生积极正面的影响,而这种影响反过来也会反馈到大尺度环流对台风移向移速的变化上,陈旧的台风初始化方案和不合理的台风数值预报业务系统流程已经严重阻碍了中国台风数值预报业务水平的进一步发展.最近,中国国家气象中心利用新开发的台风初始化方案、基于全球数值模式建立了新一代的台风数值预报业务系统,相比于旧系统而言,新系统巧妙地将台风初始化过程与全球资料分析同化-预报循环系统融合在了一起,这使得改进目前台风路径数值预报效果成为可能.应用新的台风数值预报系统,文中对2006年生成于西北太平洋23个不同类型的台风进行了连续数值试验,统计分析表明,新系统在改进台风路径预报效果上有了不俗的表现,相比于业务使用的人造bogus涡旋方案而言,120 h预报时效内的平均路径误差有了十几公里到上百公里的下降.该系统在2007年台风季节投入了实时试验运行,并取得了令人惊喜的预报效果.
중국국가기상중심기우전구수치모식、채용인조bogus와선초시화방안건립기래적태풍수치예보업무계통시독립우전구자료분석동화-예보순배과정래운행적.실제상,태풍와선시전구수치예보중일개중요적、밀불가분적중척도계통,태풍적정학묘술회대주위적대척도형세예보산생적겁정면적영향,이저충영향반과래야회반궤도대척도배류대태풍이향이속적변화상,진구적태풍초시화방안화불합리적태풍수치예보업무계통류정이경엄중조애료중국태풍수치예보업무수평적진일보발전.최근,중국국가기상중심이용신개발적태풍초시화방안、기우전구수치모식건립료신일대적태풍수치예보업무계통,상비우구계통이언,신계통교묘지장태풍초시화과정여전구자료분석동화-예보순배계통융합재료일기,저사득개진목전태풍로경수치예보효과성위가능.응용신적태풍수치예보계통,문중대2006년생성우서북태평양23개불동류형적태풍진행료련속수치시험,통계분석표명,신계통재개진태풍로경예보효과상유료불속적표현,상비우업무사용적인조bogus와선방안이언,120 h예보시효내적평균로경오차유료십궤공리도상백공리적하강.해계통재2007년태풍계절투입료실시시험운행,병취득료령인량희적예보효과.
Currently, the TC numerical prediction system at National Meteorological Center (NMC) of China is based on a global model using the initialization scheme of inserting a bogus vortex into the analysis field. Because the structure of the bogus vortex is not dynamically and physically consistent with the global model, the TC prediction system has always been run independent of the global analysis-forecast cycle since it was put into operation. In fact, TC circulation is one of the important components of large-scale analy-sis. An accurate description of initial TC structure will produce a positive effect on forecasting of large-scale circulation. In return, the large-scale circulation can steer TC's movement and speed correctly at each forecast time. Obviously, the TC prediction system with the bogus vortex scheme is so antiquated that it cannot provide better forecasts of TC track for operational use. Recently, a new TC numerical prediction system has been developed using a new TC initialization scheme based on the global analysis-forecast cycle in or-der to increase the skill of TC track forecasts. While the bogus vortex initialization of the old operational prediction system is carried out after data analysis, the TC initialization of the new system is accomplished before data analysis. It is significant that a few obser-vations related to TC are not rejected during the quality check of the data assimilation, because the background field in which TC has been initialized is more consistent with observational data. The new TC numerical prediction system for TC forecasts over the western North Pacific was established at NMC in late 2006. To evaluate the impact of the new scheme on TC track predictions, 23 different TCs during the 2006 TC season were examined, which enables us to identify the case-to-case variability in the forecast results. It was found that the new scheme produced more accurate TC track forecass compared with the old bogus scheme. Statistical analysis shows a decrease in the average track error by 11% - 23% in the 12 to 120 h forecast time periods for the 2006 typhoon season. The new TC numerical prediction system was applied to operational forecast parallel tests in the 2007 typhoon season and it showed improved performance in TC track forecasts. The system was scheduled to be into operation in place of the old TC system in 2008.