期刊名称：Tellus A: Dynamic Meteorology and Oceanography
电子版ISSN：1600-0870
出版年度：2020
卷号：72
期号：1
页码：1-13
DOI：10.1080/16000870.2019.1697164
摘要：The role of planetary-scale zonally-asymmetric thermal forcing on large-scale atmospheric dynamics is crucial
for understanding low-frequency phenomena in the atmosphere. Despite its paramount importance, good
theoretical foundation for the understanding is still lacking. Here, we address this issue by providing a
general framework for including planetary-scale thermal forcing in large-scale atmospheric dynamics studies.
This is accomplished by identifying two distinct geostrophic motions of horizontal length scale L in terms of
the external Rossby deformation length scale LD: i) L e0 LD and ii) L e1=2LD, where is the Rossby
number. In addition, via multi-scale analysis, we show that the large-scale atmospheric dynamics can be
described by mutual interaction between the two scales. The analysis results in planetary geostrophic
equations with large-scale thermal forcing that provide the basic balanced states for processes such as the
growth of synoptic waves. In the long-time limit, the continuous growth and decay of synoptic waves provide
the convergence of horizontal heat and vorticity fluxes, which contributes to the energy flux balance in the
planetary geostrophic scale with planetary-scale advection and thermal forcing.
