Collaborative Research: Observations and Analysis of Wave-Induced Constituent Transport in the Mesopause Region above Cerro Pachon, Chile and Table Mountain, Colorado

这是一个为期5年的科学合作项目，目的是利用理论、观测和大气化学模型相结合的方法研究上层中间层和下层热层（MLT）的垂直输送机制。本研究聚焦于80-105 km高空的中层顶区域，利用智利Cerro Pachon和CO. Table Mountain两个观测点的Na和Fe风/温度激光雷达、流星雷达和气辉数据。目的是量化这些观测点以上中层顶区域的波致垂直输送，表征其对热量、Na、Fe、O和其他关键成分通量和垂直分布的影响。并将测量结果与传统上用于解释大气化学模型中垂直输送的涡流扩散参数化方案进行比较。具体的科学目标包括：1)研究了整个中流层区域全年的热通量、Na（在Cerro Pachon）和Fe（在Table Mountain）垂直通量特征；2)确定了与平流、湍流混合、动力输运和Na/Fe化学相关的有效垂直成分输运速度及其季节变化特征；(3)通过比较模式预测与观测，量化波致输运对中间层Na和Fe层结构和季节变化的影响；(4)表征Cerro Pachon全年OH Meinel波段、O（1S）绿线和O2大气波段气辉发射相关的有效垂直输运；5)通过模式计算来评估波致输运对其他重要的中间层成分（如原子o）的结构和变化的影响。智力优势：了解波致垂直输运的大小和变化对广泛的研究问题具有重要意义，包括一般环流模式、大气化学模式、热平衡计算以及中间层气辉和金属层的研究。这项工作将有助于更深入地了解关键的重力波输运过程及其与大气化学的关系。此外，这项工作将大大提高我们模拟MLT组成结构的能力，特别是大气金属层和气辉层。更广泛的影响：该研究对大气科学具有更广泛的影响，因为其结果可用于表征波致传输对其他大气区域其他重要成分的影响，例如平流层臭氧，而平流层臭氧反过来又影响地球大气的热平衡。因此，该项目的结果可能在全球气候模式中有重要的应用。此外，对中间层铁和钠垂直通量的直接测量，结合模拟，将大大改善目前对全球大气输入通量绝对值的估计，这是高度不确定的。这一点很重要，因为进入MLT的陨石碎片最终会被输送到低层大气中，在那里它会影响平流层气溶胶的形成，并最终沉积在海洋中，在那里它有助于铁等关键化学物质的浓度。平流层气溶胶和海洋铁在地球气候中都起着重要作用。平流层气溶胶反射阳光，这改变了地球的辐射收支，而海洋铁促进浮游植物的生长，影响全球碳循环，特别是大气中的二氧化碳。

This is a 5-year scientific collaboration to investigate vertical transport mechanisms in the upper mesosphere and lower thermosphere (MLT) using a combination of theory, observations, and atmospheric chemical models. The study focuses on the mesopause region, 80-105 km altitude, and employs Na and Fe wind/temperature lidar, meteor radar, and airglow data from two observation sites at Cerro Pachon, Chile, and Table Mountain, CO. The objectives are to quantify wave-induced vertical transport in the mesopause region above these sites, to characterize its effects on the fluxes and vertical distribution of heat, Na, Fe, O, and other key constituents, and to compare the measurements to the eddy diffusion parameterization schemes that are traditionally used to account for vertical transport in atmospheric chemistry models. Specific scientific goals include: 1) To characterize the vertical fluxes of heat, Na (at Cerro Pachon) and Fe (at Table Mountain) throughout the mesopause region and throughout the year, 2) To determine the effective vertical constituent transport velocities associated with advection, turbulent mixing, dynamical transport and Na/Fe chemistry and to characterize their seasonal variations, 3) To quantify the influence of wave-induced transport on the structure and seasonal variations of the mesospheric Na and Fe layers by comparing model predictions with observations, 4) To characterize the effective vertical transport associated with OH Meinel Band, O(1S) green line and O2 Atmospheric Band airglow emissions throughout the year at Cerro Pachon, and 5) Through model calculations to assess the influence of wave-induced transport on the structure and variations of other important mesospheric constituents such as atomic O. Intellectual Merit: Knowledge of the magnitude and variability of wave-induced vertical transport is important to a wide range of research problems, including general circulation modeling, atmospheric chemistry modeling, thermal balance calculations, and the study of the mesospheric airglow and metal layers. This work will contribute to a much deeper understanding of the key gravity wave transport processes and their relationships to atmospheric chemistry. In addition, this work will significantly enhance our ability to model the constituent structure of the MLT, particularly the meteoric metal and airglow layers. Broader Impacts: The research has broader implications for atmospheric science because the results can be used to characterize the impact of wave-induced transport on other important constituents in other atmospheric regions, such as stratospheric ozone, which in turn affects the thermal balance of the Earth's atmosphere. Hence, the results of this project may have important applications in global climate modeling. Furthermore, the direct measurements of the vertical fluxes of mesospheric Fe and Na, in combination with modeling, will substantially improve current estimates of the absolute value of the global meteoric input flux, which are highly uncertain. This is important because the meteoric debris that enters the MLT is eventually transported into the lower atmosphere, where it affects the formation of stratospheric aerosols and is ultimately deposited in the oceans, where it contributes to the concentration of key chemical species, such as Fe. Both stratospheric aerosols and oceanic Fe play important roles in Earth's climate. Stratospheric aerosols reflect sunlight, which alters the Earth's radiation budget, while oceanic Fe promotes the growth of phytoplankton, which affects the global carbon cycles, in particular atmospheric CO2.