CAREER: The Influence of Desert Heat Lows on Monsoon Precipitation

这是一个教师早期职业发展（CAREER）项目，以支持在开发和进行大气科学研究和教育的综合5年计划的初级教师。研究部分审查季风与沙漠之间的联系，这些沙漠通常位于季风区向极地一侧的邻近地区（例如，撒哈拉在萨赫勒的向极地一侧并与萨赫勒相邻）。 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，沙漠热低压产生浅翻转环流，其中700毫巴附近的外流有一个向赤道的分量，通过温暖和干燥的对流层中部的季风深对流区域，减少季风降水。 为了促进对这种季风-沙漠关系的理解，该奖项下的工作将解决三个主要问题：1）沙漠热低压中的浅水流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)在沙漠热低压和季风之间的相互作用中，低层瞬变涡旋有多重要？ 3)在西非、南亚和澳大利亚，热低压与季风降水的相互作用方式是否基本相同？这些研究问题是通过一个三部分的研究议程，其中的任务是1）表征季风-沙漠关系的观测发现，基于组合的现场，卫星和再分析数据集：2）探索这些关系使用一个简单的理论模型;和3）使用状态进行过程研究-艺术数值模式。这个职业建议的教育部分涉及季风预报比赛的发展，有三个目标：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）领域的高潜力，代表性不足的高中生的招聘和保留;和3）创建一个传播和讨论季风预报和研究的国际社区。季风预报比赛通过一个网站举行，参赛者可以输入西非、印度、澳大利亚和北美季风区的开始日期和季节性降水总量的预报。 参与者被要求提交一份沿着的理论依据和他们的预测，该网站还包含关于季风的教育材料，沿着对流的基本科学解释，从压力梯度产生风，以及其他相关主题。 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，以及与业务产品的链接。作为预测竞赛的一部分，该项目寻求季风区居民作为预报员和博客参与，以提供关于季风及其对人类影响的真实世界视角。预测比赛是伴随着一个教育推广工作，以纽黑文公立学校系统。外展活动是通过科学合作动手学习和研究（SCHOLAR）计划进行的，在该计划中，学生参加耶鲁大学为期三周的暑期科学课程。PI正在与SCHOLAR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，两名学生将被选中参加由PI部门组织的实地考察。

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.