Collaborative Research: Instabilities and Turbulence in Gravity Wave Dissipation and Formation of Thermospheric Sodium Layers above the Andes

合作研究：重力波耗散的不稳定性和湍流以及安第斯山脉上方热层钠层的形成

• 批准号: 1759471
• 负责人: Alan Liu
• 金额: $ 109.6万
• 依托单位: Embry-Riddle Aeronautical University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1759471&HistoricalAwards=false
• 关键词: Collaborative; Research; Instabilities; Turbulence; Gravity

This award will fund continued operations of a sodium (Na) wind-temperature (W&T) lidar at the Andes Lidar Observatory (ALO) in Cerro Pachon, Chile (30.25 S, 70.74 W, elev. 2530 m) supporting scientific studies aimed at the dynamics of mesopause atmospheric instabilities and turbulence structures formation resulting from the gravity wave (GW) dissipation processes for a spatial region above the Andes where the population of mountain GW events is abundant. The Na lidar at ALO is a state-of-the-art resonance-fluorescence Doppler lidar, capable of measuring 3D wind, neutral temperature and Na density profiles with excellent vertical and temporal resolutions within the 80-105 km altitude range (referred to as the MLT region) and with high accuracy. Other possible W&T lidar studies would include the extension of lidar observations into the lower thermosphere, with wind and temperature measurements up to 140 km altitude for the somewhat frequent occurrence of thermospheric sodium layers. The formation of such layers is not understood and will be a significant topic of research in this award. Another interesting application of the ALO observatory is the detection of turbulence scale perturbations in the mesosphere and lower thermosphere temperature and wind profiles that are related to the formation of atmospheric unstable layers and dissipation of GW events.A point of great interest was how the results of this research might be applicable to other planetary atmospheres where the same issues of fluid dynamics come into play because the same energy transfer mechanism applies to these environments. The details of this mechanism that transfers translational energy associated with meteorological systems at low altitudes into a heat source that is significant at MLT altitudes are poorly understood. This conversion process is known to be related to the decreasing exponential neutral density. As the GW structure propagates into the upper region, a conversion process comes into play through dissipation processes that this award would define by undertaking the comparison of observations with the predictions of modelling studies centered upon the question of the initiation, development, and evolution of turbulent structures. Another issue relating to this award area of study is the opportunity to study the atmospheric effects of a total solar eclipse that will be happening in 2019 in Chile.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项将资助位于智利帕雄山安第斯激光雷达天文台（ALO）（南纬 30.25，西经 70.74，海拔 2530 m）的钠 (Na) 风温 (W&T) 激光雷达的持续运行，支持旨在安第斯山脉上方空间区域的重力波（GW）耗散过程导致中层顶大气不稳定性和湍流结构形成的动力学，其中山地人口GW活动丰富。 ALO 的 Na 激光雷达是最先进的共振荧光多普勒激光雷达，能够在 80-105 公里高度范围内测量 3D 风、中性温度和 Na 密度剖面，具有出色的垂直和时间分辨率（称为MLT 区域）并且具有高精度。其他可能的 W&T 激光雷达研究将包括将激光雷达观测扩展到较低的热层，对于经常出现的热层钠层，进行高达 140 公里高度的风和温度测量。这些层的形成尚不清楚，将成为该奖项的一个重要研究主题。 ALO 天文台的另一个有趣的应用是检测中层和较低热层温度和风廓线中的湍流尺度扰动，这些扰动与大气不稳定层的形成和引力波事件的消散有关。这项研究可能适用于其他行星大气，在这些大气中，同样的流体动力学问题也会发挥作用，因为相同的能量传递机制也适用于这些环境。这种将低海拔气象系统相关的平移能量转移到 MLT 高度上重要的热源的机制的细节人们知之甚少。已知该转换过程与指数中性密度递减有关。当引力波结构传播到上部区域时，转换过程通过耗散过程开始发挥作用，该奖项将通过将观测结果与模型研究的预测进行比较来定义，该模型研究的重点是湍流的起始、发展和演化问题。结构。与该奖项研究领域相关的另一个问题是有机会研究 2019 年智利将发生的日全食对大气的影响。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力评估进行评估，认为值得支持。优点和更广泛的影响审查标准。

项目成果

Kelvin‐Helmholtz Billow Interactions and Instabilities in the Mesosphere Over the Andes Lidar Observatory: 1. Observations

• DOI: 10.1029/2020jd033414
• 发表时间: 2020-11
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: J. Hecht;D. Fritts;L. Gelinas;R. J. Rudy;R. Walterscheid;A. Z. Liu

Mesosphere and Lower Thermosphere Changes Associated With the 2 July 2019 Total Eclipse in South America Over the Andes Lidar Observatory, Cerro Pachon, Chile

• DOI: 10.1029/2021jd035064
• 发表时间: 2022-05
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: Cerro Pachon;F. Vargas;A. Liu;G. Swenson;C. Segura;P. Vega;J. Fuentes;D. Pautet;M. Taylor;Y. Zhao;Y. Morton;H. Bourne

On the Long Lasting “C‐Type” Structures in the Sodium Lidargram: The Lifetime of Kelvin‐Helmholtz Billows in the Mesosphere and Lower Thermosphere Region

• DOI: 10.1029/2019ja026630
• 发表时间: 2019-04
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: S. Mondal;S. Sarkhel;Jay Agarwal;D. Chakrabarty;R. Sekar;T. Yuan;X. Cai;A. Liu;S. Nozawa;N. Saito;T. Kawahara;M. Mlynczak;J. Russell

Seasonal Variation of Vertical Heat and Energy Fluxes due to Dissipating Gravity Waves in the Mesopause Region Over the Andes

• DOI: 10.1029/2020jd033825
• 发表时间: 2021-02
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: Yafang Guo;A. Liu

Parameterizing Wave‐Driven Vertical Constituent Transport in the Upper Atmosphere

参数化波驱动的高层大气垂直成分输运

• DOI: 10.1029/2019ea000625
• 发表时间: 2019
• 期刊: Earth and Space Science
• 影响因子: 3.1
• 作者: Gardner, Chester S.;Guo, Yafang;Liu, Alan Z.
• 通讯作者: Liu, Alan Z.