The Impact of Tropical/Extratropical Interaction on Atmospheric Teleconnections

热带/温带相互作用对大气遥相关的影响

• 批准号: 1401220
• 负责人: Steven Feldstein
• 金额: $ 65.67万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1401220&HistoricalAwards=false
• 关键词: Impact; Tropical; Extratropical; Interaction; Atmospheric

This project has the goal of improving understanding of the basic dynamical processes that drive tropical/extratropical interaction on the intraseasonal time by performing both idealized numerical model experiments and diagnostic analyses. Enhanced understanding of tropical/extratropical interaction is crucial for improving medium range (1-4 week) weather forecasts. Recent studies have shown that different phases of an active tropical Madden-Julian Oscillation (MJO) are followed 1-4 weeks later by the excitation of the dominant Northern Hemisphere teleconnection patterns (both the North Atlantic Oscillation and the Pacific/North American patterns), and coincide with large changes in the frequency of occurrence of these teleconnection patterns. It has been found that probabilistic weather forecasts based on both MJO and El-Nino-Southern-Oscillation phases outperform state-of-the-art numerical weather prediction models for North America with lead times of 2 to 4 weeks. Changes to Arctic surface air temperature have even been observed following an active MJO.

该项目的目标是通过进行理想化的数值模式实验和诊断分析，提高对驱动季节内热带/热带外相互作用的基本动力过程的理解。加强对热带/热带外相互作用的理解对于改进中期（1-4周）天气预报至关重要。最近的研究表明，活跃的热带马登-朱利安涛动（MJO）的不同阶段在1-4周后被主导的北方半球遥相关型（北大西洋涛动和太平洋/北美型）激发，并且与这些遥相关型发生频率的大变化相一致。已经发现，基于MJO和El-Nino-Southern-Oscillation阶段的概率天气预报优于北美最先进的数值天气预报模型，提前时间为2至4周。在活跃的MJO之后，甚至观察到北极表面空气温度的变化。