CAREER: The Influence of Desert Heat Lows on Monsoon Precipitation

职业：沙漠低热对季风降水的影响

• 批准号: 1253222
• 负责人: William Boos
• 金额: $ 64.35万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1253222&HistoricalAwards=false
• 关键词: CAREER; Influence; Desert; Heat; Lows

This is a Faculty Early Career Development (CAREER) project to support a junior faculty member in developing and conducting an integrated 5-year program of research and education in atmospheric science. The research component examines the connection between monsoons and the deserts typically found adjacent to monsoon regions on the poleward side (as, for instance, the Sahara is poleward of and adjacent to the Sahel). Previous work by the PI shows that variations in precipitation in several monsoon regions including the Sahel, South Asia, and Australia, are positively correlated with equivalent potential temperature below the cloud layer over adjacent poleward deserts. One hypothesis for this relationship is that desert heat lows produce shallow overturning circulations in which outflow near the 700mb level has an equatorward component which reduces monsoon precipitation by warming and drying the mid-troposphere over the region of monsoonal deep convection. To advance understanding of such monsoon-desert relationships, work under this award will address three main questions: 1) Does shallow flow in desert heat lows alter monsoon precipitation primarily through horizontal advection of moisture and dry static energy? 2) How important are low-level transient eddies in interactions between desert heat lows and monsoons? 3) Do heat lows interact with monsoon precipitation in fundamentally the same way in West Africa, South Asia, and Australia? These research questions are addressed through a three-part research agenda in which the tasks are 1) characterize the monsoon-desert relationships found in observations, based on a combination of in situ, satellite, and reanalysis datasets; 2) explore these relationships using a simple theoretical model; and 3) conduct process studies using a state-of-the-art numerical model.The educational component of this CAREER proposal involves the development of a monsoon forecasting contest with three goals: 1) fostering education on weather, climate, and relevant basic science; 2) enhancing recruitment and retention of high-promise, underrepresented high school students in science, technology, engineering, and math (STEM) fields; and 3) creating an international community for disseminating and discussing monsoon forecasts and research. The monsoon forecasting contest is held through a website which allows participants to enter forecasts of onset date and total seasonal precipitation for the monsoon regions of West Africa, India, Australia, and North America. Participants are asked to submit a rationale along with their predictions, and the website also contains educational materials on monsoons, along with basic science explanations for convection, generation of wind from pressure gradients, and other relevant topics. Guidance for forecasters, including climatological monsoon onset date and precipitation amount, the state of El Nino, and links to operational products. As part of the forecasting contest, the project seeks the participation of inhabitants of monsoon regions as forecasters and as bloggers, to provide a real-world perspective on monsoons and their human impacts. The forecasting contest is accompanied by an educational outreach effort to the New Haven Public School system. The outreach is conducted through the Science Collaborative Hands-On Learning And Research (SCHOLAR) program, in which students take part in a three-week residential summer science program at Yale. The PI is working with SCHOLAR staff to develop a short science module on weather, climate, and monsoons. In addition, in the last three years of the project, two students will be selected to attend a field trip organized by the PI's department.

这是一个教师早期职业发展（Career）项目，旨在支持一名初级教师开发和实施一个综合的5年大气科学研究和教育计划。研究部分考察了季风和沙漠之间的联系，这些沙漠通常是在靠近极地的季风地区发现的（例如，撒哈拉沙漠是靠近极地的萨赫勒地区）。PI先前的工作表明，包括萨赫勒、南亚和澳大利亚在内的几个季风区的降水变化与邻近的极地沙漠云层下的等效潜在温度呈正相关。这种关系的一个假设是，沙漠热低压产生浅层翻转环流，其中700毫巴高度附近的流出有一个赤道分量，通过使季风深层对流区域对流层中部变暖和变干来减少季风降水。为了进一步了解这种季风-沙漠关系，本奖项下的工作将解决三个主要问题：1)沙漠热低压的浅层流动是否主要通过水分和干静态能量的水平平流改变季风降水？2)低层瞬变涡旋在沙漠热低压与季风的相互作用中有多重要？3)在西非、南亚和澳大利亚，热低压与季风降水的相互作用是否基本相同？这些研究问题通过一个由三部分组成的研究议程来解决，其中的任务是：1)根据现场、卫星和再分析数据集的组合，描述观测中发现的季风-沙漠关系；2)用一个简单的理论模型探讨这些关系；3)使用最先进的数值模型进行过程研究。这项CAREER计划的教育部分涉及开展季风预报竞赛，其目标有三个：1)促进天气、气候和相关基础科学的教育；2)加强在科学、技术、工程和数学（STEM）领域招募和留住有前途的、代表性不足的高中生；3)建立一个传播和讨论季风预报和研究的国际社会。季候风预报比赛透过网站举行，参赛者可输入预报西非、印度、澳洲及北美季候风地区的开始日期及总季降水。参与者被要求提交一份基本原理和他们的预测，该网站还包含有关季风的教育材料，以及对流、气压梯度产生风和其他相关主题的基础科学解释。为预报员提供的指导，包括气候季风开始日期和降水量、厄尔尼诺状态以及业务产品的链接。作为预报比赛的一部分，该计划寻求季风区居民以预报员和博客的身份参与，提供一个真实的视角，了解季风及其对人类的影响。预报比赛还伴随着对纽黑文公立学校系统的教育推广工作。外展是通过科学协作实践学习和研究（SCHOLAR）项目进行的，学生们在耶鲁大学参加为期三周的住宿暑期科学项目。PI正在与SCHOLAR的工作人员合作开发一个关于天气、气候和季风的简短科学模块。此外，在项目的最后三年，将选出两名学生参加由PI部门组织的实地考察。