报告题目：Seasonal Tropical-Extratropical Teleconnections Originating from Tropical Rainfall Modes Independent of the Niño 3.4 Index in Northern Winters
报告人：彭沛焘 资深研究科学家 （美国NOAA气候预测中心）
邀请人：杨修群 教授
时间：2024年4月16日，周二10:00-11:30
地点：D103报告厅
报告摘要：
彭沛焘，资深研究科学家。长期在美国NOAA气候预测中心从事研发工作，涉及领域包括短期气候变化的分析和模拟，预测方法开发，以及极端气候事件的归因分析等。主要工作包括：最早提出用多模式集合预测短期气候及可行性分析，短期气候可预报性的系统性分析，大气低频模态的分解及其在气候预测中的应用，海温强迫对大气模态的影响，基于构造相似方法的全球亚季节-季节-年际气候预测系统， 神经网络在短期气候预测中的应用，北美气候异常的归因分析，源于热带热力强迫模态的遙相关及其在气候归因分析中的应用等。
报告人简介：
This study, based on an analysis with observational and reanalysis data, highlights seasonal tropical-extratropical atmospheric teleconnections originating from tropical rainfall modes unrelated to the Niño 3.4 index for northern winters. The mode decomposition for tropical rainfall is done by first removing the Niño 3.4 index related variability from the tropical rainfall and then applying rotated empirical orthogonal function (REOF) analysis to the residual. The corresponding teleconnection patterns are obtained by regressing global atmospheric fields against the time series of the rainfall modes. Analyses of the tropical heating-atmospheric circulation relationship indicate that the circulation anomalies corresponding to the rainfall modes are forced response to the corresponding rainfall mode. The teleconnection patterns reveal some new features and show that some intrinsic mid-latitude patterns can be triggered by tropical forcing with different rainfall patterns. Results from this study are relevant to seasonal climate attribution and prediction analyses and climate model evaluation. As an illustration, the teleconnections from the rainfall modes, together with that related to the Niño 3.4 index and linear trend, are applied to the attribution analyses for the global circulation anomalies of 2019/2020 winter and the California dry condition during the strong El Niño winter of 2015/2016. The overall impact of these modes in the period of 1980-2021 is also discussed.
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