Collaborative Research: Convection and Rainfall Enhancement over Mountainous Tropical Islands

合作研究：热带山区对流和降雨增强

• 批准号: 1740536
• 负责人: Rajagopalan Balaji
• 金额: $ 5.94万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1740536&HistoricalAwards=false
• 关键词: Collaborative; Research; Convection; Rainfall; Enhancement

More rain falls over tropical islands than nearby ocean areas. This enhancement of island rainfall occurs for multiple reasons, including triggering of thunderstorms by daytime heating of islands and associated sea breezes, as well as by winds blowing over mountainous islands. Although island rainfall may seem like a local subject of study, an improved understanding of it has several benefits that cut across study of global weather and climate. For example, rainfall over the large islands of the western Tropical Pacific (such as Borneo, Papua New Guinea, and Sumatra) influences wind patterns along the equatorial Pacific basin at both weather (a few weeks) and climate (seasonal) time scales. Also, a deeper understanding of tall thunderstorms in the tropics remains a major obstacle to better weather forecasts and reducing uncertainty in climate change projections. Connected with this, studying island rainfall may help address questions about whether it tends to rain more over wet or dry soils and why; these questions are important for understanding the persistence of floods and droughts. Finally, understanding how island rainfall depends on the temperature of the nearby ocean remains a challenge. This temperature-dependence is important not only for the societal impacts of rainfall extremes in a changing climate, but also because dissolved minerals found in the runoff from all land - but particularly tropical islands - can regulate atmospheric carbon dioxide content and global temperature over periods of millions of years. The goal of this project is to address these questions that cut across weather, current climate, and past climate, by using high-resolution numerical model simulations of the atmosphere to investigate how island rainfall enhancement depends on multiple factors of the island environment. These factors include the temperature of the nearby ocean, the wetness and height of the island, the strength of the winds impinging on the island, and the size of the region simulated in the numerical model. This research project will advance knowledge about the tropical convection processes that regulate the climate, by studying how tropical convections are influenced by local aspects of the island environment. The research project supports a graduate student who will gain training in climate dynamics and preparation for a career in teaching and research in academia or commercial weather prediction, thus sustaining the pool of human resources required for excellence in climate research. Publicly available instructional videos will be produced to illustrate central concepts associated with island thunderstorms and rainfall, including sea-breezes and the pattern of thunderstorm triggering over the day. A set of tools for analyzing the output generated by the high-resolution numerical model of the atmosphere will be made available to undergraduate students, graduate students, and postdoctoral researchers.

热带岛屿的降雨量比附近海域的降雨量多。岛屿降雨量的增加有多种原因，包括岛屿的白天加热和相关的海风以及吹过多山岛屿的风引发的雷暴。尽管岛屿降雨看起来似乎是一个地方性的研究课题，但对它的更好理解有几个好处，可以贯穿全球天气和气候的研究。例如，热带太平洋西部大岛(如婆罗洲、巴布亚新几内亚和苏门答腊岛)上的降雨在天气(几周)和气候(季节性)时间尺度上都会影响赤道太平洋盆地的风型。此外，更深入地了解热带地区的高雷暴仍然是更好的天气预报和减少气候变化预测的不确定性的主要障碍。与此相关的是，研究岛屿降雨可能有助于解决这样的问题：在潮湿或干燥的土壤上降雨更多，以及为什么；这些问题对于理解洪水和干旱的持续性很重要。最后，理解岛屿降雨量如何取决于附近海洋的温度仍然是一个挑战。这种温度依赖性不仅对气候变化中极端降雨的社会影响很重要，而且因为在所有陆地--特别是热带岛屿--的径流中发现的溶解矿物质可以调节数百万年期间的大气二氧化碳含量和全球温度。该项目的目标是解决这些跨越天气、当前气候和过去气候的问题，通过使用高分辨率大气数值模式模拟来研究岛屿降雨增加如何依赖于岛屿环境的多种因素。这些因素包括附近海洋的温度、岛屿的湿度和高度、冲击岛屿的风的强度以及数值模式中模拟的区域大小。这项研究项目将通过研究热带对流如何受到岛屿环境的局部影响来促进对调节气候的热带对流过程的了解。该研究项目支持一名研究生接受气候动力学培训，并为在学术界或商业天气预报领域从事教学和研究工作做好准备，从而维持在气候研究方面取得卓越成就所需的人力资源库。将制作公开提供的教学视频，以说明与岛屿雷暴和降雨有关的中心概念，包括海风和一天中引发雷暴的模式。本科生、研究生和博士后研究人员将获得一套用于分析高分辨率大气数值模式产生的输出的工具。