T-PARC: Ensemble Simulation and Clustering of the Evolving Cyclone Structure Through Extratropical Transition (ET)

T-PARC：通过温带过渡 (ET) 演化的气旋结构的集合模拟和聚类

• 批准号: 0735973
• 负责人: Jenni Evans
• 金额: $ 47.54万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-01 至 2012-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0735973&HistoricalAwards=false
• 关键词: PARC; Ensemble; Simulation; Clustering; Evolving

This research addresses multiple scientific goals of the THe Observing system Research and Predictability EXperiment (THORPEX) Pacific Asian Regional Campaign (T-PARC) including (i) advancing knowledge of the dynamics governing North Pacific Extratropical cyclone Transitions (ET) as the storms move poleward, (ii) improving the interpretation and utility of ensemble forecast systems, and (iii) testing the improvement in local and downstream forecast skill afforded by high-resolution, non-hydrostatic modeling of ET. It is also synergistic with the goals of the THORPEX Integrated Grand Global Ensemble to (i) develop new methods to combine ensembles, and (ii) enhance collaboration on development of ensemble prediction, internationally and between operational centers and universities. Tropical cyclones undergoing extratropical transition (ET) experience rapid structural changes as they transform from a deep, warm core cyclone to a cold core cyclone. This presents a major forecasting problem and a numerical modeling challenge. It remains an open question whether the hybrid structure of the transitioning cyclone is sufficiently well resolved to capture the complex process of transition, but the PI's assessment of the forecast skill of two global operational models at simulating ET timing and structure evolution finds the deterministic forecasts from these operational models to be lacking. Ensemble prediction systems offer the potential for assessing confidence in numerical guidance during cases of ET by exploring the uncertainties in the initial vortex and environment structures. In this project, European Centre for Medium-Range Weather Forecasting (ECMWF) ensemble forecasts of storm structure are evaluated within the framework of the cyclone phase space (CPS). This collaborative effort between meteorology and statistics will encompass: (1) development of cyclone structure-based sub-ensembles for track and intensity forecasts of ET; (2) extension of the objective partitioning of storm structure evolution to mixture-based clustering of CPS tracks; and (3) quantification of the ECMWF ensemble forecast spread in terms of initial vortex structure. Intellectual merit of the research lies in both the creative exploitation of novel statistical and numerical modeling methods to investigate the factors forcing cyclone structure evolution through the ET of initially tropical cyclones. Broader impacts of this research include the application of novel statistics techniques to synoptic meteorology and testing the effectiveness of the Weather Research and Forecast Model configuration for simulating ET. Societal impacts include the potential for improvements in local severe weather forecasts associated with ET, as these are critically dependent on the cyclone structure.

这项研究解决了观测系统研究和可预报性实验（THORPEX）太平洋亚洲区域运动（T-PARC）的多个科学目标，包括（i）随着风暴向极地移动，提高对北太平洋外热带气旋转换（ET）的动力学知识，（ii）改善集合预报系统的解释和实用性，以及（iii）测试高分辨率、非流体静力学ET模型对当地和下游预报技术的改进。它还与THORPEX综合全球大集合的目标具有协同作用，以（i）开发新的方法来组合联合收割机集合，以及（ii）加强国际上以及业务中心和大学之间在集合预测发展方面的合作。热带气旋在经历向热带气旋外转变（ET）的过程中，会经历快速的结构变化，从一个深而温暖的核心气旋转变为一个冷的核心气旋。这提出了一个主要的预测问题和数值模拟的挑战。它仍然是一个悬而未决的问题，是否过渡气旋的混合结构是足够好地解决捕捉复杂的过渡过程，但PI的两个全球业务模型在模拟ET时间和结构演变的预测技能的评估发现，这些业务模型的确定性预测是缺乏的。包围预测系统通过探索初始涡和环境结构中的不确定性，提供了在ET情况下评估数值制导置信度的潜力。在这个项目中，欧洲中期天气预报中心（ECMWF）集合预报的风暴结构的气旋相空间（CPS）的框架内进行评估。 气象学和统计学之间的这种合作努力将包括：（1）为ET的路径和强度预报开发基于气旋结构的子集合;（2）将风暴结构演变的客观划分扩展到基于混合物的CPS路径聚类;以及（3）根据初始涡旋结构量化ECMWF集合预报传播。该研究的智力价值在于创造性地利用新的统计和数值模拟方法来研究通过初始热带气旋ET迫使气旋结构演变的因素。这项研究的更广泛的影响包括应用新的统计技术，天气学和测试的有效性的天气研究和预报模型配置模拟ET。社会影响包括改善与ET相关的当地恶劣天气预报的潜力，因为这些预报严重依赖于气旋结构。