An Observational Study of Intramonthly Quasi-Periodicities in the Northern Heimsphere, Extratropical Geopotential Height Field

本研究旨在研究北半球温带冷季对流层位势高度10-30天的准周期现象。对这种现象的探索在实验、理论和观测基础上都是合理的。他们将以理论为指导进行审查。将利用各种统计技术来评估这些现象的重要性并量化其重要性。与大多数其他这类研究不同，这些现象的非平稳性将直接纳入分析和显着性检验。此外，这些分析将考虑到地区性，并将基于比以往大多数此类性质的研究更大的样本。旋转复主成分(RCPC‘s)将在本研究中使用。RCPC分析技术是一种强大的统计工具，直到最近才被引入气象学家。这种方法和几种更简单的方法将产生幅度和相位的时间序列。统计检验将主要针对这些时间序列进行。这项研究的结果应考虑到对流层高度在10-30天范围内变化的各个方面，包括准周期现象的规律性、持续时间以及准周期现象与准静止状态的关系。这项研究之所以重要，是因为它对一组长期、高质量的大气环流观测进行了严格的统计分析，以寻求季节内振荡对气候特征的重要性这一问题的答案。

This research is aimed at investigating 10-30 day quasi- periodic phenomena in the extratropical, cold season tropospheric geopotential heights of the Northern Hemisphere. The search for such phenomena is justified on experimental, theoretical and observational grounds. They will be examined using theory as guidance. A variety of statistical techniques will be utilized in order to assess the significance and quantify the importance of such phenomena. Unlike most other studies of this type the non-stationarity of these phenomena will be incorporated directly into the analyses and significance testing. Also, the analyses will allow for regionality and will be based on a much larger sample than most prior studies of this nature. Rotated complex principal components (RCPC's) will be used in this study. The RCPC analysis technique, which is a powerful statistical tool, has been introduced to meteorologists only very recently. This and several simpler approaches will yield time series of amplitude and phase. The statistical tests will be performed primarily on these time series. The results of this study should put into prospective various aspects of the variability of tropospheric heights in the 10-30 day range, including regularity, duration and relation of the quasi-periodic phenomena to the quasi-stationary state. This research is important because it applies rigorous statistical analysis to a long-term, high quality set of atmospheric circulation observations to seek answers to the question of the importance of intraseasonal oscillations on climate characteristics.