Mechanisms of Convection-Wave Interactions

该项目旨在提高对热带对流波相互作用的理解，重点是周期小于2.5天的带状传播惯性重力波扰动。这种扰动之所以引起人们的兴趣，是因为它们与日周期有着密切的联系，并在强热带风暴（如1992年的安德鲁飓风）的形成中发挥着潜在的作用。 此外，高分辨率卫星数据的时空谱显示，这些高频波模式的传播方向有一个戏剧性的向西偏置，乞讨解释，也许持有波对流调制机制的关键线索。 一套精心设计的嵌套云解析模式实验上的一个统一的赤道β平面将使用天气研究预报（WRF）模式系统进行，以测试假设是什么原因造成这种不对称。 进一步的见解将收集详细的诊断分析，使用以前的工作中开发的技术。 这些分析将应用于来自理想化WRF模式运行的数据，以及来自其他更大的现实边界条件模式运行的数据;以及来自观测的数据。 为了评估模拟波结构的真实性，将对温度，湿度和风的复合无线电探空仪观测进行详细的比较。 这样的观测组合已经存在低频波，但将扩展到日和更高的频率。先前确定的热带对流波生命周期跨尺度的自相似性预计将扩展到这些相对较短/快速的波，但与系统的频率差异表明温度和湿度在波动动力学中的相对作用的线索。 观测部分的一个重要创新是引入2006年发射的CloudSat的垂直分辨云结构观测。这项工作的科学成果预计将对大气科学产生广泛影响，为改进通用区域和全球模式中使用的对流参数化提供有用的信息。一些建模和诊断技术将被打包并作为WRF模型的"开箱即用"功能的增强功能提供，作为更广泛的区域建模社区的服务。该项目还将有助于研究生的培训和指导。

This project seeks to improve understanding of convection-wave interactions in the Tropics, with an emphasis on zonally-propagating, inertia-gravity wave disturbances with periods less than 2.5 days. Such disturbances are of interest owing to their strong ties to the diurnal cycle and potential role in the genesis of severe tropical storms, such as Hurricane Andrew 1992. Furthermore, space-time spectra of high-resolution satellite data show a dramatic westward bias in the propagation direction of these high-frequency wave modes, begging explanation and perhaps holding critical clues about wave-convection modulation mechanisms. A suite of carefully designed nested cloud-resolving model experiments on a uniform equatorial beta-plane will be performed using the Weather-Research Forecast (WRF) model system, to test hypotheses about what causes this asymmetry. Further insights will be gleaned from detailed diagnostic analyses, using techniques developed in previous work. These analyses will be applied to data from the idealized WRF model runs, as well as from other, much larger, realistic-boundary-condition model runs; and from observations. To assess the realism of the simulated wave structures, detailed comparisons will be made against composite radiosonde observations of temperature, moisture, and winds. Such observational composites already exist for low-frequency waves, but will be extended to diurnal and higher frequencies. The previously identified self-similarity of tropical convective wave life cycles across scales is expected to extend to these relatively short/fast waves, but with systematic differences across frequencies suggesting clues about the relative roles of temperature and moisture in wave dynamics. An important novelty of the observational component will be to bring in vertically-resolved cloud structure observations from CloudSat, which was launched in 2006.Scientific results of this work are expected to have broad impact in the atmospheric sciences by usefully informing efforts at improving convective parameterizations used in general-purpose regional and global models. Some of the modeling and diagnostic techniques will be packaged and offered as enhancements to the WRF model's "out-of-the-box" capabilities, as a service to the broader regional modeling community. This project will also contribute to the training and mentorship of a graduate student.