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

这个博士后研究奖是为了对热带云的自我批判行为进行理想化的数值模拟研究。在这种情况下，自我批判行为是指云在其周围环境达到一定湿度水平时迅速成长为降雨生产者的现象。这在很大程度上是为了防止大气过度潮湿而发生的。然而，该奖项的研究旨在发现自我批判在单个云层面上扮演的角色。该奖项的一个成功成果将是增进对云过程的了解，从而改进天气和气候模式。该研究人员还计划教授和指导本科生，目标是影响更多的学生从事科学事业。本研究将使用海洋-陆地-大气模式（OLAM）进行。研究人员将讨论与单个云的生长有关的两个主题，云微物理和重力波。这项工作的第一个假设是，某些云微物理过程在临界水分值附近变得有效。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，临界值应该被打破或移动。第二个假设是，随着云的降雨率增加，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。这一假设将通过短时间步长运行模型并跟踪波浪以及它们如何与附近的云相互作用来验证。该博士后奖学金将由澳大利亚墨尔本大学和迈阿密大学罗森斯蒂尔海洋与大气科学学院平分。该奖项得到了国际和综合活动办公室的资助。

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.