CEDAR Postdoc: Momentum Fluxes and Height Variability of Mesospheric Gravity Waves Obtained by Airglow Imagers

在中层/低热层区域（~80-100 km），短周期重力波对全球尺度动力学具有非常重要的影响。然而，这些重力波对中间层区域的影响的定量研究仍然需要做。为了理解它们的影响，重要的是能够量化这些波携带的动量通量。气辉成像仪数据已被证明是测量中层重力波小尺度水平结构及其引起的强度扰动的非常有用的仪器。然而，它是由重力波引起的温度扰动，需要直接估计的重力波携带的动量通量。以前，研究人员已经应用了一个抵消因子CF来将温度与强度扰动联系起来。然而，CF使用的是一个模型预测，并没有得到充分的验证，从测量，因为直到最近，它一直难以测量强度和温度扰动。在这个项目中，研究人员将使用一种名为中间层温度成像仪（MTM）的特殊全天空相机，同时测量强度和温度波，以研究CF及其对垂直波长的依赖性。然后，MTM数据将用于对动量通量进行季节性研究，并将其能力扩展到其他类型的全天照相机。这将使未来的全球规模的研究，使用许多成像仪，现在在世界各地运行，以测量重力波的属性。除了这项主要研究，计划通过扩展落基山成像仪链来帮助开发断层成像能力，以允许对重力波结构高度变化进行新的测量，并研究波浪破碎的影响。发展层析成像技术来研究中间层的重力波，重力波在中间层存款动量，这将大大提高我们调查所涉及的主要过程的能力。这项研究可能会打开大门，利用现有的多站气辉和流星雷达测量在更大的规模上的动量通量的定量调查。此外，它将帮助我们了解重力波能量传输的季节变化和纬度依赖性，从而更清楚地了解中间层气候和潜在的气候变化。

In the mesosphere/lower thermosphere region (~80-100 km), short-period gravity waves have a very important role influencing the global-scale dynamics. However, quantitative investigations on the effects of these gravity waves on the mesospheric region still need to be done. To understand their effects it is important to be able to quantify the momentum flux carried by these waves. Airglow imager data have proven to be very useful instruments for measuring small-scale horizontal structure of mesospheric gravity waves as well as their induced intensity perturbations. However, it is the temperature perturbations caused by the gravity waves that are needed to directly estimate the momentum flux carried by the gravity waves. Previously, researchers have applied a cancellation factor CF to relate the temperature to the intensity perturbations. However, the CF used is a model prediction and has not been verified sufficiently from the measurements because, until recently, it has been difficult to measure both intensity and temperature perturbations. For this program, investigators will use a special all-sky camera called the Mesospheric Temperature Mapper (MTM) to simultaneously measure the intensity and temperature waves to investigate CF and its dependence on vertical wavelength. The MTM data will then be used to make a seasonal study of momentum flux and to extend the capability to other types of all-sky cameras. This will allow a future, global scale, study to be made using the many imagers that are now operated around the world to measure gravity wave properties. In addition to this main study it is planned to help develop a tomographic imaging capability by extending the Rocky Mountain Imager Chain to permit new measurements of gravity wave structure height variability and to study the effects of wave breaking. The development of tomographic capabilities to study the gravity waves in the mesosphere, where they deposit their momentum, will significantly enhance our ability to investigate the dominant process involved. This study may open the door to quantitative investigations of momentum flux on a much larger scale using existing multi-station airglow and meteor radar measurements. Moreover, it will help us understand the seasonal variations and latitudinal dependences of energy transportation of gravity waves, leading to a clearer understanding of mesospheric climate and potential climate change.