CEDAR: Planetary Wave Induced Tidal Variability

大气潮汐是地球大气基本状态（风、温度和密度）的全球尺度振荡，它在低层大气中受到强迫，并垂直传播到高层大气和电离层。在过去的十年中，对大气潮汐迁移的基本理解已经出现，主要是由于全球地面观测站数量的增加，这些观测站对大约在70至120公里之间的中间层和低层热层（MLT）进行风和温度测量。来自地面和空间仪器的观测数据的不断增加，为大气科学家提供了机会，以提高他们对驱动大气潮汐的机制的理论认识。这是通过一个包括数值模型和观测数据的过程来完成的。这项研究的基本方法是使用美国国家大气研究中心正在开发的全大气群落气候模型（WACCM）。WACCM是一个从地表到140千米高度的全非线性四维大气环流模式。WACCM的分析结果将与全球MLT观测网络进行比较，包括最近发射的TIMED航天器的观测结果，以验证该模型模拟的潮汐和行星波结构。一旦得到验证，该模式将用于估计全球尺度行星波对大气潮汐结构的影响。

The atmospheric tides are global scale oscillations in the basic state of the Earths atmosphere (winds, temperature and density) that are forced in the lower-atmosphere and propagate vertically into the upper atmosphere and ionosphere. Over the past decade basic understanding of the migrating atmospheric tides has emerged, largely from an increase in the number of ground-based observatories across the globe making wind and temperature measurements of the mesosphere- and lower-thermosphere (MLT) roughly between 70 and 120km. The continuing increase in the availability of observational data from ground and space based instruments is providing atmospheric scientists with the opportunity to improve their theoretical understanding of the mechanisms that drive atmospheric tides. This is accomplished through a process that includes both numerical models and observational data. The basic approach for this research is to use the Whole Atmosphere Community Climate Model (WACCM) that has been under development at the National Center for Atmospheric Research. WACCM is a fully nonlinear, four-dimensional global circulation model of the atmosphere spanning from the surface to an altitude of 140km. Analysis of WACCM results will be compared with the global network of MLT observations, including those from the recently launched TIMED spacecraft, to validate the tidal and planetary wave structure simulated by the model. Once validated, the model will be utilized to estimate the affect of global scale planetary waves on the structure of the atmospheric tides.