发表机构
Hillsdale College; University of California, Davis（希尔斯代尔学院; 加州大学戴维斯分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文建立热带大气对流动量传输的多尺度理论，推导非局域动量扩散算子，拓展经典Matsuno-Gill模型，揭示对流诱导动量传输对热带环流和赤道波动力学的系统修正作用。
AI 中文摘要
本文采用多尺度渐近框架分析小尺度对流环流场与大尺度热带环流之间的相互作用，推导了控制大尺度流动的闭合方程，为未解析对流的影响提供了系统闭合方案。未解析对流的影响通过非局域动量扩散算子体现，该算子是对流动量传输的第一性原理表示，可自然耦合大尺度环流的垂直斜压模态。经典Matsuno-Gill模型作为极限近似被重新推导，此时推导得到的动量传输算子简化为Gill引入的唯象阻尼，从而将经典理论建立在系统的第一性原理基础上。本文考虑广义理论的两个应用：首先，研究局地赤道对称加热驱动的稳态环流，结果显示对流诱导的垂直模态耦合会激发超出直接强迫的额外斜压模态，显著改变沃克环流的垂直结构；其次，分析赤道波谱，得到的本征模态包含经典赤道波族的混合，导致频散关系失去清晰的分支结构并出现系统的频率偏移。这些结果表明，对流诱导的动量传输如何系统地改变稳态热带环流和赤道波动力学。
英文摘要
A multiple-scales asymptotic framework is employed to analyze the interaction between a field of small-scale convective circulations and the large-scale tropical circulation. Closed equations governing the large-scale flow are derived, providing a systematic closure for the influence of unresolved convection. The influence of unresolved convection enters through a non-local momentum diffusion operator that provides a first-principles representation of convective momentum transport and naturally couples the vertical baroclinic modes of the large-scale circulation. The classical Matsuno--Gill model is recovered as a limiting approximation in which the derived momentum transport operator reduces to the phenomenological damping introduced by Gill, thereby placing the classical theory on a systematic first-principles foundation. Two applications of the generalized theory are considered. First, steady-state circulations driven by localized equatorially symmetric heating are examined. Convectively induced vertical-mode coupling is shown to excite additional baroclinic modes beyond those directly forced, substantially modifying the vertical structure of the Walker circulation. Second, the equatorial wave spectrum is analyzed. The resulting eigenmodes comprise mixtures of the classical equatorial wave families, causing the dispersion relations to lose their distinct branch structure and exhibit systematic frequency shifts. These results demonstrate how convectively induced momentum transport systematically modifies both steady tropical circulations and equatorial wave dynamics.
