Mechanisms of Climate Variability and Change

将在非纬向平均的情况下研究对流层近环形变率形式的低频变率。将酌情利用再分析数据产品和模式，研究时均状态的纬向不对称性对维持这些异常及其转变的作用。将使用全球模式研究大尺度对流加热在驱动赤道地区纬向风结构和对流层顶温度方面的作用。将在一系列受控实验中研究季节性、赤道对称性和纬向不对称性对赤道纬向风和对流层顶温度的影响，并将这些实验与观测结果进行比较。此外，热带和亚热带层状云甲板的辐射冷却在驱动浅环流中的作用，以及它们与深对流的相互作用将在一个简单的模拟环境中和预测对流加热的气候模式中进行研究。将研究平流层和对流层的相互作用，特别是平流层变暖在强迫对流层气候方面的作用。这将包括使用全大气社区气候模型（WACCM1b）和社区气候系统模型的当前大气成分（称为CAM）以及可用观测的建模研究。通过平流层和对流层的路径与热带的连接将被调查和比较。更广泛的影响：三名研究生将在此赠款下支持。其中一人将来自科学界代表性不足的群体。这项工作将有助于验证和测试由NSF，CAM和WACCM模型支持的社区气候模型。PI将在廉价的集群计算机上测试这些模型的使用情况，并就如何在小组环境中构建和维护这种气候建模基础设施向其他人提供指导。这项工作对季节预报和气候变化预测具有潜在的重要意义。

Low-frequency variability of the troposphere in the form of near-annular variability will be studied in a non-zonally averaged context. Using reanalysis data products and models, where appropriate, the role of zonal asymmetries of the time-mean state on the maintenance of these anomalies and their transitions will be investigated. The role of large-scale convective heating in driving the zonal wind structure and tropopause temperature in the equatorial region will be investigated using global models. The effect of seasonality, equatorial symmetry and zonal asymmetry on the equatorial zonal wind and tropopause temperature will be investigated in a series of controlled experiments, which will be compared to observations. In addition, the role of the radiative cooling of tropical and subtropical stratiform cloud decks in driving shallow circulations, and their interaction with deep convection will be investigated in a simple modeling context and within the context of climate models that predict convective heating. The interaction of the stratosphere and the troposphere and particularly the role of stratospheric warmings in forcing tropospheric climate will be investigated. This will include modeling studies using the Whole Atmosphere Community Climate Model (WACCM1b) and the Community Climate System Model's current atmospheric component (known as CAM), as well as available observations. The connections to the tropics through stratospheric and tropospheric pathways will be investigated and compared.Broader Impacts:Three graduate students will be supported under this grant. One of them will be from an underrepresented group within the sciences. The work will contribute to the validation and testing of the community climate models supported by NSF, the CAM and the WACCM models. The PI will test the utilization of these models on inexpensive cluster computers and provide guidance to others on how to build and maintain this climate modeling infrastructure in a small group setting. The work has potentially important implications for seasonal forecasting and climate change projections.