Tropical Gravity Waves and Latent Heating: Making the Invisible Visible

这项研究将包括协同使用重力波、降水和云观测，以及局部区域模式，以研究对流上升气流尺度潜热和波阻对环流的新限制。围绕对流云的重力波是复杂的、三维的、时变的现象。通过应用专门设计的两种区域模式工具，结合已有的观测资料，将潜热和波的不可见特征都呈现出来。该项目侧重于将这些新知识应用于亚电网尺度重力波阻力问题，用于全球气候预测和天气预报。经过观测验证的重力波解析模式表明，从对流云中发射的重力波的尺度和传播具有局域的、云内潜热快速变化的四维特征。该团队将检验以下两个假设：(1)对重力波和降水的观测限制了对流云中潜在加热的局部瞬时特性；(2)潜热的知识可以用来构建波场的缺失特征，以准确评估它们对环流的远程影响。热带重力波阻力是平流层低层风准二年生振荡（QBO）的主导驱动力，其本身是北半球冬季季节和年际气候可预测性和热带季节内和年际降水可预测性的主导因子。从这个项目中获得的关于重力波的知识将提供重力波动量通量变率及其与对流云的关系的清晰图像，这将使更准确的预测和未来气候预测成为可能。这项研究将产生重大的科学和社会影响。这包括：(a)预测飞机感受到的晴空乱流；(b)遥远海洋地区飓风加强的早期预警；(c)提高热带天气预报技能；(d)非迁移潮汐对中层大气风的影响；(e)预测电离层扰动和通信信道中断。该项目将为一名早期职业科学家提供培训。该项目还将支持一名女性PI，这是STEM研究中一个代表性不足的群体的成员。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The research will involve a synergistic use of gravity wave, precipitation, and cloud observations together with local-area models for new constraints on convective updraft-scale latent heating and wave drag on circulation. Gravity waves surrounding convective clouds are complex, three-dimensional, time-varying phenomena. Through application of two specially designed regional model tools together with available observations, the research can make the invisible features of both the latent heating and the waves visible. The project focuses on applying this new knowledge to the problem of subgrid-scale gravity wave drag for global climate prediction and weather forecasting. Gravity wave resolving models that have been observationally validated indicate that the scales and propagation of gravity waves emitted from convective clouds carry the signature of the four-dimensional properties of the localized, rapid variations in latent heating inside the clouds.The team will examine the following two hypotheses: (1) Observations of gravity waves and precipitation constrain the local, instantaneous properties of latent heating inside convective clouds; and (2) Knowledge of the latent heating can be used to construct the missing features of the wave field needed to accurately assess their remote effects on circulation.Tropical gravity wave drag is the leading force driving the quasibiennial oscillation (QBO) in lower stratospheric winds, which itself is a leading factor in Northern Hemisphere wintertime seasonal and interannual climate predictability and tropical intraseasonal and interannual precipitation predictability. The knowledge of gravity waves gained from this project will provide a clear picture of the gravity wave momentum flux variability and relation to convective clouds, which will permit more accurate predictions and future climate projections.The research will have substantial scientific and societal impacts. These include: (a) forecasting clear air turbulence felt by aircraft; (b) early warning of hurricane intensification over remote ocean areas; (c) improving tropical weather forecast skill; (d) nonmigrating tidal influences on middle atmosphere winds; and (e) forecasting ionospheric disturbances and communication channel disruptions. The project will provide training to an early career scientist. The project would also support a female PI, a member of an under-represented group in STEM research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.