General Circulation Studies

这个正在进行的研究项目的主要目标是 提高我们对大气的认识和预测 随时间尺度的变化超过一周。 研究 包括对观测数据和模型生成数据的诊断 集合，使用统计技术，如简单的合成， 时域数字滤波，主分量，信号处理 分析和典型相关分析，并强调 根据我们目前的研究结果， 了解大尺度大气动力学。 这项工作是 与大气环流建模项目密切相关， NCAR和NOAA/GFDL，以及业务和实验数值 NOAA/NMC和ECMWF的天气预报。 周期在数周或更长时间的波动 都是由内部的动力过程产生的， 大气层和大气层之间的相互作用 底层介质（主要是海洋和陆地表面 水文学）。 相关动态包括各种进程 在低频下运行，以及高频的强迫 与斜压不稳定相关的频率瞬变。 通过 仔细分析空间模式和时间序列， 经过时间过滤的气象场，PI希望隔离 与各种流程相关的签名，并记录如何 它们对总的可变性有贡献。 这项研究很重要，因为它有助于 我们预测大气变化能力的直接途径 与人类活动相关的时间尺度。

The primary objective of this ongoing research project is to improve our understanding and prediction of atmospheric variability with time scales longer than a week. The research involves the diagnosis of observational and model generated data sets, using statistical techniques such as simple compositing, digital filtering in the time domain, principal component analysis and canonical correlation analysis, and emphasizing the dynamical interpretation of the results in light of our current understanding of large-scale atmospheric dynamics. The work is closely linked to projects in general circulation modeling at NCAR and NOAA/GFDL and to operational and experimental numerical weather prediction at NOAA/NMC and ECMWF. Fluctuations with periods on the order of weeks and longer are generated both by dynamical processes internal to the atmosphere and by interactions between the atmosphere and the underlying media (primarily the oceans and the land-surface hydrology). The relevant dynamics include a variety of processes that operate on low-frequencies, as well as the forcing by high frequency transients associated with baroclinic instability. By careful analysis of the spatial patterns and time sequences of time-filtered meteorological fields, the PIs hope to isolate the signatures associated with the various processes and document how they contribute to the total variability. This research is important because it contributes in a direct way toward our ability to predict atmospheric variability on time-scales relevant to human activities.