Tropical/Extratropical Interaction Mechanisms at the Intraseasonal Time Scale

季节内时间尺度的热带/温带相互作用机制

基本信息

批准号：
1822015
负责人：
Steven Feldstein
金额：
$ 61.35万
依托单位：
Pennsylvania State Univ University Park
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1822015&HistoricalAwards=false
关键词：
Tropical Extratropical Interaction Mechanisms Intraseasonal

项目摘要

This project has the potential to lead to an improvement of the subseasonal (2-6 week) probabilistic weather forecasts of temperature and precipitation for North America. Support for this outcome is based upon the previous research by the team on the influence of tropical weather on mid-latitude weather, which has contributed to the development of the probabilistic subseasonal weather forecast method used by NOAA. This project will also train a graduate student to become an independent scientist. Besides participating in the usual activities of publishing papers and giving conference presentations, the team will work with personnel at Penn State's Center for Science and the Schools to conduct a five-day workshop on subseasonal to seasonal (S2S) prediction for middle and high school teachers from low socioeconomic and racially diverse urban and rural Pennsylvania school districts that serve populations highly underrepresented in science, technology, engineering, and math fields. The teachers will attend lectures on the techniques used for S2S forecasting, and participate in relevant inquiry-based activities. The team will provide follow-up support as the teachers implement the workshop activities in their classrooms.In the tropics, the dominant pattern on the intraseasonal time scale, the Madden-Julian Oscillation (MJO), is characterized by organized precipitation systems that propagate eastward encircling the tropics on a timescale of 30-70 days. The importance of the MJO for forecasting is evidenced by the use of the state of the MJO in week-3 and week-4 probabilistic forecasts by the NOAA/Climate Prediction Center. Although much progress has been made during the past three decades toward understanding how tropical convective heating influences the weather in mid-latitudes, there are still important unaddressed questions. This project will focus on questions that have not yet been investigated or have received little previous attention: (1)investigation of how Rossby waves are excited by MJO-related convection in the tropics propagate pole-ward,and impact weather in the mid-latitudes; (2) variation in the horizontal and vertical structure of the latent heat released in convections within the MJO event, and its impact in a key region, the central subtropical North Pacific; and (3) role of inertio-gravity waves excited by MJO-related convections in connecting tropical convections to weather over large distances across the Earth, e.g., teleconnection patterns. The team will also address the following questions: Why does the high latitude component within teleconnection patterns persist for a much longer time period than do their lower latitude counterparts? What is the impact of inertio-gravity waves excited by the MJO on mid-latitude weather? The topic is particularly important because active teleconnection patterns have a large influence on the weather up to 6 weeks later. The approach includes the use of observational datasets and computer model calculations. The computer model will be used to isolate and to better understand the key physical processes that are responsible for the tropical-extratropical teleconnections.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目有可能改善北美次季节（2-6 周）温度和降水概率天气预报。这一结果的支持是基于该团队之前关于热带天气对中纬度天气影响的研究，该研究有助于 NOAA 使用的概率次季节天气预报方法的发展。该项目还将培养一名研究生成为一名独立科学家。除了参加发表论文和进行会议演讲的常规活动外，该团队还将与宾夕法尼亚州立大学科学中心和学校的人员合作，为初中和高中教师举办为期五天的次季节到季节（S2S）预测研讨会来自社会经济水平较低、种族多样化的宾夕法尼亚州城乡学区，这些学区为科学、技术、工程和数学领域代表性严重不足的人群提供服务。教师将参加有关 S2S 预测技术的讲座，并参加相关的探究活动。当教师在课堂上实施研讨会活动时，该团队将提供后续支持。在热带地区，季节内时间尺度的主导模式马登-朱利安振荡 (MJO) 的特点是有组织的向东传播的降水系统环绕热带地区的时间为30-70天。 NOAA/气候预测中心在第 3 周和第 4 周概率预报中使用 MJO 的状态证明了 MJO 对预报的重要性。尽管过去三十年来在了解热带对流加热如何影响中纬度地区天气方面取得了很大进展，但仍然存在一些重要的未解决问题。该项目将重点研究尚未研究或以前很少受到关注的问题：（1）研究热带地区与MJO相关的对流激发的罗斯贝波如何向极地传播，以及如何影响中纬度地区的天气; (2) MJO事件内对流释放潜热的水平和垂直结构变化及其对北太平洋中副热带重点区域的影响； (3) MJO 相关对流激发的惯性重力波在将热带对流与地球上长距离天气连接起来时的作用，例如遥相关模式。该团队还将解决以下问题：为什么遥相关模式中的高纬度部分比低纬度部分持续更长的时间？ MJO激发的惯性重力波对中纬度天气有何影响？这个话题特别重要，因为活跃的遥联系模式对 6 周后的天气有很大影响。该方法包括使用观测数据集和计算机模型计算。该计算机模型将用于隔离和更好地理解导致热带-温带遥相关的关键物理过程。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。