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

这一博士后研究奖是对热带云中自我批评行为的理想化数值模拟研究。这里的自我批评行为是指当云的周围环境达到一定的湿度水平时，云迅速成长为降雨产生者的现象。人们普遍认为，这种情况的发生是为了防止大气过度受潮。然而，该奖项的研究旨在发现自我临界性在个人云水平上扮演的角色。这一奖项的一个成功结果将是增进对云过程的理解，以改进天气和气候模型。研究人员还计划教授和建议本科生，目的是影响更多的本科生追求科学事业。这项研究将使用海洋-陆地-大气模型(OLAM)进行。这位研究人员将研究与单个云的增长有关的两个主题，即云微物理和重力波。这项工作的第一个假设是，某些云微物理过程在临界湿度附近变得有效。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，临界值应该会被打破或转移。第二个假设是，随着来自云层的降雨率增加，产生的重力波的幅度也会增加。这反过来会产生更多的云和降雨，迫使系统回到稳定状态。这一假设将通过以较短的时间步长运行模型并跟踪海浪以及它们如何与附近的云相互作用来检验。这一博士后奖学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。

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.