Empirical Decomposition of Low-Frequency Atmospheric Variability for Climate Dynamics Studies

气候动力学研究中低频大气变率的经验分解

• 批准号: 0332364
• 负责人: Ka-Kit Tung
• 金额: --
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-11-01 至 2008-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0332364&HistoricalAwards=false
• 关键词: Empirical; Decomposition; Low; Frequency; Atmospheric

This project will apply Empirical Mode Decomposition (EMD), a technique for analyzing time series recently developed by Huang et alia (1998), to the 45-year long NCEP reanalysis assimilation in order to study the spatial and temporal structure present in low frequency atmospheric variability. Such variability includes the global Quasi-Biennial Oscillation, a possible El Nino-Southern Oscillation mode, a possible 11-year solar cycle signal, a 22-year cycle (so far unidentified) and a warming trend in the troposphere believed to arise from cooling of the stratosphere. The principal objective of this work is to understand the nature of low frequency variability in the atmosphere, perhaps offering a facility to differentiate between the naturally-occurring and anthropogenically-induced components of this variability.The use of a new method (EMD) will broaden the scope of analysis techniques to probe long-term variability in the atmosphere. The results are expected to benefit the scientific community, and will be disseminated via international scientific journals and major conferences. One female post-doctoral student will receive support and training.

本项目将利用Huang等人（1998）最近开发的一种分析时间序列的技术——经验模态分解（EMD），对长达45年的NCEP再分析同化进行研究，以研究低频大气变率的时空结构。这种变化包括全球准两年一次振荡、可能的厄尔尼诺-南方涛动模式、可能的11年太阳周期信号、22年周期（迄今尚未确定）以及据信由平流层变冷引起的对流层变暖趋势。这项工作的主要目标是了解大气中低频变率的性质，也许可以提供一种方法来区分这种变率的自然发生成分和人为诱发成分。使用一种新的方法（EMD）将扩大分析技术的范围，以探测大气中的长期变化。研究结果预计将使科学界受益，并将通过国际科学期刊和主要会议传播。1名女博士后将获得支持和培训。