The Dynamics of Low-Frequency Phenomena

低频现象的动力学

• 批准号: 9526030
• 负责人: Peter Webster
• 金额: $ 119.85万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-11-15 至 2001-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9526030&HistoricalAwards=false
• 关键词: Dynamics; Low; Frequency; Phenomena

Abstract ATM-9526030 Webster, Peter J. University of Colorado Title: The Dynamics of Low-Frequency Phenomena The PI will investigate and describe: o The morphology of the monsoon and its relationship with other circulation systems. This project represents a major new initiative in the study of low frequency phenomena. o Wave propagation through the very complex background flow of tropics. The PI plans to extend earlier work and to investigate the impact of vertical shear on equatorial wave propagation and, finally consider all shears and stretching deformations concurrently. o Intraseasonal variability from the perspective of coupled ocean-atmosphere dynamic systems. The PI notes that the location of convection in the tropics and its organization on the intraseasonal time scales remains largely unexplained. He plans to investigate this organization from a fundamental perspective relative to the coupled ocean-atmosphere system. The monsoons and the circulation associated with the east-west sea- surface temperature (SST) gradients produce a slowly evolving system within which resides a large proportion of the interannual variability of the climate system. The slow migrations of convection clusters which make up the intraseasonal variability in the tropics may be products of the low frequency monsoon-ENSO system. To a first approximation, the regions where equatorial transient waves accumulate their energy or where they influence higher latitudes is determined by the slowly evolving state of the monsoon-ENSO system. The PI proposes a program in which the low frequency monsoon-ENSO systems is defined within the context of ocean-atmosphere-land coupling. This research is important because it seeks knowledge about the factors that control the seasonal-to-interannual variability of the climate. Such knowledge is required in order to improve the prediction of climate variability on these time s cales.

ATM-9526030韦伯斯特，彼得J.科罗拉多大学题目：低频现象的动力学PI将调查和描述：o季风的形态及其与其他环流系统的关系。这个项目代表了研究低频现象的一项重大新举措。波在非常复杂的热带背景气流中传播。PI计划扩展早期的工作，研究垂直切变对赤道波传播的影响，最后同时考虑所有的切变和拉伸变形。O从海洋-大气动力耦合系统的角度看季节内的可变性。PI指出，热带对流的位置及其在季节内时间尺度上的组织在很大程度上仍未得到解释。他计划从海洋-大气耦合系统的基本观点来研究这个组织。季风和与东西海面温度梯度有关的环流形成了一个缓慢演变的系统，气候系统年际变化的很大一部分都在这个系统中。构成热带季节内变率的对流团的缓慢迁移可能是低频季风-ENSO系统的产物。首先，赤道瞬变波积累能量的区域或它们影响高纬度的区域是由季风-ENSO系统缓慢演变的状态决定的。PI提出了一个方案，在该方案中，低频季风-ENSO系统是在海洋-大气-陆地耦合的背景下定义的。这项研究很重要，因为它寻求关于控制气候季节到年际变化的因素的知识。为了改进对S估计的这些时间的气候变化的预测，这些知识是必要的。