The Cross-equatorial Influences of South American Rainfall on the North Atlantic and Adjacent Continents

南美洲跨赤道降雨对北大西洋及邻近大陆的影响

• 批准号: 1917781
• 负责人: Rong Fu
• 金额: $ 67.94万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1917781&HistoricalAwards=false
• 关键词: Cross; equatorial; Influences; South; American

The influence of one-hemisphere on another hemisphere is an important component of global weather and climate teleconnections. Most of previous research has been focused on teleconnections over the eastern Pacific during boreal winter season through the propagation of the atmospheric planetary (Rossby) waves across the equator. Over the American-Atlantic sector, various interhemispheric teleconnection pathways control the influence of Amazonia deforestation and of extreme cold front incursions on weather and climate variability over the North American and Europe. Two of the outstanding questions are what are the dynamic processes that control these teleconnections and how they affect droughts, floods and the tracks of tropical storms. This proposal will address this knowledge gap by testing three hypotheses about the mechanisms behind the interhemispheric teleconnection pathways over the American-Atlantic sector. The insights from the project will help advance our understanding of cross-equatorial teleconnections and may have implications for improving sub-seasonal to interannual climate predictability over the North Atlantic and the surrounding continents, including North America, Europe, and Africa. The latter is also central for characterizing the potential influences of rapidly changing Amazonian rainforests on global atmospheric circulation and climate. The main broader impacts involve training of two graduate students from underrepresented groups, mentoring of undergraduate research. The research findings will be incorporated into a large upper-division undergraduate science course. The project also supports visitations of faculty members from South America to help build networks of U.S. colleges and universities, especially for students, with international academic institutions and organizations. They will consider three dynamic processes operating in different seasons responsible for cross-equatorial teleconnections originated from diabatic heating anomalies over South America: (i) cross-equatorial propagation of the Rossby waves generated by diabatic heating over the South American Monsoon to influence the North Atlantic Oscillation during boreal winter, (ii) convective coupled eastward propagating Kelvin waves from Amazonia that influences tropical Atlantic surface winds, sea-level height anomalies, and western Congo rainfall variability in boreal spring, and (iii) a shallow cross-equatorial circulation connecting cold air incursions from the extratropical South America to influence weather and climate variability of the tropical and subtropical North Atlantic in boreal summer. The PI plan to evaluate these hypotheses through observational analyses and a suite of idealized numerical model experiments.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.

一个半球对另一个半球的影响是全球天气和气候遥相关的重要组成部分。以前的大多数研究都集中在通过大气行星（罗斯比）波在赤道上的传播，在北方冬季东太平洋上空的遥相关上。在美洲-大西洋地区，各种半球间遥联系途径控制着亚马逊森林砍伐和极端冷锋入侵对北美和欧洲天气和气候变化的影响。两个悬而未决的问题是，控制这些遥相关的动态过程是什么，以及它们如何影响干旱、洪水和热带风暴的路径。本提案将通过测试关于美洲-大西洋地区半球间远程连接途径背后机制的三个假设来解决这一知识差距。该项目的见解将有助于提高我们对跨赤道遥相关的理解，并可能对提高北大西洋及其周边大陆（包括北美、欧洲和非洲）的亚季节至年际气候可预测性产生影响。后者也是描述迅速变化的亚马逊雨林对全球大气环流和气候的潜在影响的核心。主要的更广泛的影响包括培训两名来自代表性不足群体的研究生，指导本科生的研究。研究结果将被纳入一个大的高年级本科理科课程。该项目还支持南美教师的访问，以帮助建立美国学院和大学与国际学术机构和组织的网络，特别是为学生建立网络。他们将考虑在不同季节运行的三个动力过程，这些过程负责南美洲上空非绝热加热异常引起的跨赤道遥相关：(i)南美洲季风上空的非绝热加热产生的罗斯比波的跨赤道传播，影响北方冬季的北大西洋涛动；（ii）来自亚马逊河流域的对流耦合向东传播的开尔文波，影响热带大西洋地面风、海平面高度异常和北方春季刚果西部的降雨量变率；（iii）一个浅层的跨赤道环流，连接来自南美洲温带冷空气的入侵，影响北大西洋热带和亚热带夏季的天气和气候变率。PI计划通过观测分析和一套理想化的数值模型实验来评估这些假设。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Evaluating Seasonal Climate Forecasts from Dynamical Models over South America

• DOI: 10.1175/jhm-d-22-0156.1
• 发表时间: 2023-04
• 期刊: Journal of Hydrometeorology
• 影响因子: 3.8
• 作者: Jiaying Zhang;K. Guan;R. Fu;B. Peng;Siyu Zhao;Y. Zhuang

Climate Change in the Amazon: Tendences, Impacts and Ecological Consequences

亚马逊地区的气候变化：趋势、影响和生态后果

• 发表时间: 2021
• 期刊: Science Panel for the Amazon (SPA
• 作者: Marengo, J. C.

Variability, Trend, and Extremes of the South American Vegetation‐Climate System: Results From a Coupled Regional Model

• DOI: 10.1029/2021jd035691
• 发表时间: 2022-02
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: A. Erfanian;Yelin Jiang;Lori Fomenko;R. Fu;A. Seth;Guiling Wang