Wave-Wave Interactions and Upper Atmosphere Variability

垂直传播的大尺度波，如行星波（PW）和潮汐波（TW）是低层大气气象活动能量向高层大气传输的主要途径。这些波之间的耦合相互作用被认为是强可变性的来源，这种可变性作为可能影响导航、通信和雷达跟踪系统的二次波结构传输到高层大气和电离层。了解中间层和低热层区域这种变化的起源是空间物理学面临的主要挑战之一。该奖项将侧重于研究这些大尺度波的相互作用和它们产生的二次波，方法是使用NCAR大气环流模型（TIME-GCM）生成的长达一年的数据集，再加上使用全球尺度波模型（GSWM），该模型将模拟低层大气输入高层大气模型。研究工作的更广泛的影响将通过几种不同的方式实现：（a）通过与通过领导和多样性（BOLD）中心扩大机会的伙伴关系与不同的学生群体接触;（B）通过发现学习学徒（DLA）计划让本科生参与研究;（c）利用上述联系教研究生如何指导。对于出现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，研究两个主要波的相位如何影响二次波的生成等因素。本研究的主要目的是：1）描述和理解PWs和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-电离层系统的影响，3）评估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.