The Life Cycle Dynamics of Teleconnection Patterns

遥联系模式的生命周期动态

• 批准号: 0003039
• 负责人: Steven Feldstein
• 金额: $ 35.72万
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-12-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003039&HistoricalAwards=false
• 关键词: Life; Cycle; Dynamics; Teleconnection; Patterns

The Pacific North Atlantic (PNA) and North Atlantic Oscillation (NAO) teleconnections are known to play a very important role in climate variability and perhaps climate change. Most studies have emphasized their time-averaged (i.e., monthly, interannual, and interdecadal) properties. However, the PIs recently found that both the PNA and NAO undergo full lifecycles of growth and decay within a time period on the order of two weeks, indicating that most PNA and NAO studies are examining data that is time-averaged over several life cycles. The framework for the relationship between climate variability/change and these teleconnections can be established only with a knowledge of the very nature of the physical processes involved in these teleconnections. The goal of this grant is to identify physical processes governing the evolution of both the PNA and NAO. The approach adopted combines both diagnostic analyses of observational data and also an examination of data from idealized model calculations. Specific questions that will be addressed are (i) the mechanisms that account for the excitation of the PNA and NAO; (ii) the dynamical processes that account for the saturation i.e. termination of growth of the PNA and NAO; (iii) the role of low-frequency fluxes in the growth and decay of the PNA and NAO; and (iv) how the short timescale properties of the PNA and NAO are related to interannual variability. The work is important because it will further basic understanding of the physical processes governing the life cycle of major teleconnection in the Northern Hemisphere. In addition, these results could impact the accuracy of forecasts on time scales of weeks to seasons.

众所周知，北大西洋太平洋（PNA）和北大西洋涛动（NAO）遥相关在气候变率甚至气候变化中发挥着非常重要的作用。大多数研究都强调它们的时间平均（即月度、年际和年代际）特性。然而，PI 最近发现 PNA 和 NAO 在大约两周的时间内经历了完整的生长和衰退生命周期，这表明大多数 PNA 和 NAO 研究正在检查几个生命周期的时间平均数据。 只有了解这些遥相关所涉及的物理过程的本质，才能建立气候变率/变化与这些遥相关之间关系的框架。这笔赠款的目标是确定控制 PNA 和 NAO 演化的物理过程。所采用的方法结合了观测数据的诊断分析和理想化模型计算数据的检查。将要解决的具体问题是（i）解释 PNA 和 NAO 激励的机制； (ii) 导致饱和的动态过程，即 PNA 和 NAO 生长终止； (iii) 低频通量在 PNA 和 NAO 的生长和衰减中的作用； (iv) PNA 和 NAO 的短时间尺度特性如何与年际变率相关。 这项工作很重要，因为它将进一步基本了解控制北半球主要遥相关生命周期的物理过程。此外，这些结果可能会影响周到季节时间尺度的预测准确性。