Wave-Wave Interactions and Upper Atmosphere Variability

行星波（PW）和潮汐波（TW）等大尺度垂直传播波是低层大气气象活动的能量传输到高层大气区域的主要手段。这些波之间的耦合相互作用被认为是强变率的一个来源，这种变率作为二次波结构传播到高层大气和电离层，可能会影响导航、通信和雷达跟踪系统。了解这种变化在中间层和低层热层（MLT）区域的起源是空间物理学面临的主要挑战之一。该奖项将通过使用NCAR一般环流模式（TIME-GCM）生成的一年数据集，结合使用全球尺度波模式（GSWM），重点研究这些大尺度波相互作用及其产生的二次波，该模式将为高层大气模式提供低层大气输入的模拟。研究工作的更广泛影响将通过几种不同的方式实现：(a)通过与领导力和多样性（BOLD）中心合作，与不同的学生群体进行接触；(b)通过发现学习学徒（DLA）计划聘请一名本科生参与研究；(c)利用上述联系来教研究生如何指导。对于看到非线性相互作用的个别情况，将采用GSWM模型的非线性版本进行数值实验，研究诸如两个主波的相位如何影响二次波的产生等因素。这项工作的主要目标如下：1)描述和理解PWs与从低层大气向上传播的潮汐之间相互作用的基本机制；2)量化这些相互作用对全球大气-电离层系统施加的变率；3)评估对地基和天基观测系统的影响。

Large-scale vertically-propagating waves such as planetary waves (PW) and tidal waves (TW) represent the primary means by which energy from lower atmosphere meteorological activity is transmitted into the upper atmosphere region. The coupling interaction between these waves is believed to be a source of strong variability that is transmitted into the upper atmosphere and ionosphere as secondary wave structures that could potentially affect navigation, communications and radar tracking systems. Understanding the origins of such variability in the mesosphere and lower thermosphere (MLT) region is one of the major challenges faced in space physics. This award would focus on studying these large-scale wave interactions and the secondary waves they produce by using a year-long dataset generated by the use of a NCAR general circulation model (TIME-GCM), coupled to the use of the Global Scale Wave Model (GSWM) that would provide simulations of the lower atmosphere inputs into the upper atmosphere model. The broader impacts of the research effort will be realized in several different ways: (a) engagement with a diverse population of students through partnership with the Broadening Opportunity through Leadership and Diversity (BOLD) Center; (b) engaging an undergraduate student in the research through the Discovery Learning Apprentice (DLA) Program; (c) leveraging the above connections to teach graduate students how to mentor. For individual cases where non-linear interactions are seen, a non-linear version of the GSWM model will be employed to perform numerical experiments, investigating factors such as how the phases of the two primary waves impact the generation of the secondary waves. The primary objectives of the work are as follows: 1) to delineate and understand the basic mechanisms underlying the interactions between PWs and tides propagating up from the lower atmosphere, 2) to quantify the variability imposed on the global atmosphere-ionosphere system by these interactions, and 3) to assess the implications for ground-based and space-based observing systems.