Collaborative Research: Westerly Wind Burst Modulation by the Sea-Surface Temperature (SST): from Understanding to El Nino-Southern Oscillation (ENSO) Prediction

合作研究：海面温度（SST）对西风爆发的调节：从理解到厄尔尼诺-南方涛动（ENSO）预测

• 批准号: 0754341
• 负责人: Benjamin Kirtman
• 金额: $ 22.65万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0754341&HistoricalAwards=false
• 关键词: Collaborative; Research; Westerly; Wind; Burst

Westerly wind bursts (WWBs) are associated with the onset of major El Nino events. They occur more frequently and energetically and extend farther eastward prior to and during significant El Nino events than in non-El Nino conditions. While these wind events were initially thought to be completely stochastic, more recent analyses indicate that their occurrence and characteristics are at least partially modulated by the large-scale sea-surface temperature (SST). Model studies show that this modulation affects the characteristics of El Ninos as compared to the case of purely stochastic WWBs.This project is divided into two parts. The first, more applied, component is the implementation of an empirical WWB parameterization into a state-of-the-art El Nino-Southern Oscillation (ENSO) prediction model, in an effort to improve the skill of ENSO prediction and to assess the impact of parameterized WWBs on predictability. A previously developed empirical semi-stochastic observationally-motivated WWB model will be applied in the NCAR CCSM3.0 (National Center for Atmospheric Research Community Climate System Model 3.0) coupled ocean-atmosphere model, and this model will be used as an ENSO prediction model. The mutual effects of the WWB model and the coupled ENSO model on each other will be studied, along with the effects of the WWBs on the ENSO simulation, on the predictability of ENSO, and on the spread of predictions in the model. The second part is an effort to understand the basic mechanisms of WWBs and the dynamics of their dependence on the large-scale SST field. A cloud-resolving atmospheric model capable of producing WWBs will be run in a near-global configuration using the diabatic acceleration and rescaling (DARE) approach. The DARE model will be supplemented with analyses of observed wind and outgoing longwave radiation and with several simple models. It is intended that this strategy will result in an understanding of how the SST controls WWBs and will expose the mechanisms for the initiation and termination of the convective activity that creates WWBs.The broader impacts of this project are in contributing to improved skill in predicting ENSO, with the resulting social and economic benefits. Two graduate students will be trained: one at Harvard and one at Miami.

西风爆发（WWB）与重大厄尔尼诺事件的发生有关。与非厄尔尼诺情况相比，它们在重大厄尔尼诺事件之前和期间发生得更频繁、更强烈，并向东延伸得更远。虽然这些风事件最初被认为是完全随机的，但最近的分析表明，它们的发生和特征至少部分受到大范围海面温度（SST）的调节。模型研究表明，与纯随机WWB的情况相比，这种调制影响了厄尔尼诺的特征。该项目分为两个部分。第一个更具应用性的部分是将经验 WWB 参数化实施到最先进的厄尔尼诺南方涛动 (ENSO) 预测模型中，以提高 ENSO 预测技能并评估参数化 WWB 对可预测性的影响。先前开发的经验半随机观测驱动的WWB模型将应用于NCAR CCSM3.0（国家大气研究中心社区气候系统模型3.0）海洋-大气耦合模型，并且该模型将用作ENSO预测模型。将研究 WWB 模型和耦合 ENSO 模型之间的相互影响，以及 WWB 对 ENSO 模拟、ENSO 可预测性以及模型中预测传播的影响。第二部分是努力了解WWB的基本机制及其对大规模海表温度场依赖的动态。能够产生 WWB 的云解析大气模型将使用非绝热加速和重新缩放 (DARE) 方法在近全局配置中运行。 DARE 模型将得到对观测到的风和出射长波辐射的分析以及几个简单模型的补充。该策略旨在让人们了解 SST 如何控制 WWB，并揭示产生 WWB 的对流活动的启动和终止机制。该项目的更广泛影响是有助于提高预测 ENSO 的技能，从而产生社会和经济效益。将培训两名研究生：一名在哈佛大学，一名在迈阿密。