AGS-PRF: Investigation into the Nature of Critical Behavior in Tropical Deep Convection

AGS-PRF：热带深对流临界行为性质的调查

• 批准号: 1433164
• 负责人: Matthew Igel
• 金额: $ 17.2万
• 依托单位: Igel Matthew
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1433164&HistoricalAwards=false
• 关键词: AGS; PRF; Investigation; into; Nature

This postdoctoral research award is for an idealized numerical modeling study of self-critical behavior in tropical clouds. Self-critical behavior in this context refers to the phenomena whereby clouds grow quickly into rainfall producers when their immediate surroundings reach a certain moisture level. It is established on a large scale that this occurs in order to prevent the atmosphere from being overly moistened. However, the research in this award is aimed at discovering what role self-criticality plays on an individual cloud level. A successful outcome from this award would be increased understanding of cloud processes in order to improve weather and climate models. The researcher also plans to teach and advise undergraduate students with the goal of influencing more of them to pursue science careers.This study will be carried out using the Ocean-Land-Atmosphere Model (OLAM). The researcher will address two topics related to the growth of individual clouds, cloud microphysics and gravity waves. The first hypothesis of the work is that certain cloud microphysical processes become efficient around the critical moisture value. To test this hypothesis, the researcher will turn off the depositional process in the model, the process whereby water vapor is transferred to ice crystals. If the hypothesis is correct, the critical value should break down or shift. The second hypothesis is that as the rain rate from the cloud increases the amplitude of the created gravity waves will also increase. This would in turn create more clouds and rainfall and force the system back to a stable state. This hypothesis will be tested by running the model with a short time step and following the waves and how they interact with nearby clouds. This postdoctoral fellowship will be split between the University of Melbourne in Australia and University of Miami Rosenstiel School of Marine and Atmospheric Science. This award was supported with funding from the Office of International and Integrative Activities.

这个博士后研究奖是为热带云的自我临界行为的理想化数值模拟研究。 自我批评行为在这种情况下是指云迅速成长为降雨生产者时，他们的周围环境达到一定的湿度水平的现象。 人们普遍认为，这样做是为了防止大气层过于潮湿。 然而，该奖项的研究旨在发现自我批评在单个云级别上扮演的角色。 该奖项的成功结果将是增加对云过程的理解，以改善天气和气候模型。 研究人员还计划对本科生进行教学和建议，以影响更多的本科生从事科学事业。 研究人员将讨论与单个云的生长有关的两个主题，云微物理学和重力波。 这项工作的第一个假设是，某些云微物理过程变得有效的临界湿度值附近。 为了验证这一假设，研究人员将关闭模型中的沉积过程，即水蒸气转移到冰晶的过程。 如果假设是正确的，临界值应该分解或移动。 第二个假设是，随着云的降雨率增加，所产生的重力波的振幅也会增加。 这反过来又会产生更多的云和降雨，迫使系统回到稳定状态。 这一假设将通过以短时间步长运行模型并跟踪波以及它们如何与附近的云相互作用来进行测试。 这项博士后研究金将在澳大利亚墨尔本大学和迈阿密大学罗森斯蒂尔海洋和大气科学学院之间分配。 该奖项得到了国际和综合活动办公室的资助。