CEDAR: Numerical Investigation of Observed Multiscale Dynamics in the Middle Atmosphere

这是一项为期3年的模拟工作，将作为大气区域耦合、能量和动力学计划的一部分。大气重力波被认为在大气层之间的能量和动量传输中起着至关重要的作用。这种传输是通过这些波在背景大气中垂直传播而实现的，而这些波的消散是通过不稳定(对流和切变不稳定)的增长来实现的。本项目利用两个先进的数值模拟来研究中层-低热层(MLT)区域的重力波和不稳定过程。以前的模拟是在理想化的环境和小的周期域中进行的。在这里，模拟将扩展到深域研究，将在更真实的气流中检验这些波和不稳定过程，这些过程受到详细观测的启发。重力波是MLT动力学的一个重要强迫源，它们的影响强烈地影响着大气环流和气候模式。此外，尽管数值天气预报模式的焦点是对流层，但事实证明，当对高层大气动力学进行更准确的模拟时，数值天气预报模式可以做出更好的预测。具体地说，改进对重力波在实际流动中何时/何地变得不稳定的理解，这将是在全球尺度模式中改进这些波的参数化的关键一步。

This is a 3-year modeling effort to be undertaken as part of the Coupling, Energetics and Dynamics of Atmospheric Regions program. Atmospheric gravity waves are believed to play a vital role in the transport of energy and momentum between atmospheric layers. This transport is enabled by the propagation of these waves vertically through the background atmosphere and dissipation of these occurs via the growth of instabilities (both convective and shear instabilities). This project utilizes two advanced numerical simulations to investigate gravity wave and instability processes in the Mesosphere-Lower Thermosphere (MLT) region. Previous simulations have been performed in idealized environments and small periodic domains. Here, the simulations will be extended to deep domain studies, which will examine these wave and instability processes in more realistic flows inspired by detailed observations.Gravity waves are a significant forcing source on MLT dynamics and their effects strongly impact general circulation and climate models. In addition, numerical weather prediction models, despite their tropospheric focus, have been shown to make better predictions when the upper-atmospheric dynamics are more accurately modeled. Specifically, improved understanding of when / where gravity waves become unstable in realistic flows that would result from this effort is a vital step towards improving parametrization of these waves in global-scale models.