Collaborative Research: Quantifying KHI, Turbulence Processes and Radar Biases Using Radar Observations and In Situ Measurements at JRO and Very-High-Resolution DNS

这是一个为期3年的项目，进行开尔文-亥姆霍兹不稳定性（KHI）动力学及其对地球大气湍流和混合的影响的实验和理论研究。已知KHI发生在整个低层大气以及中间层和低层热层（MLT），并对动力学有重要贡献。此外，KHI的演变影响了VHF多普勒雷达的风测量误差，其原因是在与VHF雷达布拉格尺度相当的尺度上产生强烈、持久的分层和折射率表面的系统倾斜。这个项目解决了这两个方面。观测将在秘鲁的Jicamarca射电天文台（JRO）进行，该天文台在整个低层大气和MLT中提供了灵敏度和分辨率的特殊组合。sosu雷达（JRO）提供对流层中高度的高距离分辨率和灵敏度，再加上使用新开发的无人机系统（称为微型自主飞行器（MAV））进行的同步、定量、高分辨率的原位测量，将提供高分辨率KHI动力学和雷达测量误差的无与伦比的评估。由强大的JRO发射机和大型天线阵列提供的相对高分辨率和更高功率的能力将随后将sosu结果扩展到MLT。最后，这些观测结果将用于初始化KHI雷达后向散射和相关动力学参数的一系列数值评估，使用一种新的能力来执行直接数值模拟（DNS），以表征和指导一般流动条件下伴随这些动力学的测量误差。来自KHI的雷达风测量的不准确性是理解基本上所有运动尺度上的大气动力学的一个限制因素，包括：平均运动、风切变、大尺度潮汐和行星波活动、小尺度重力波动力学、小尺度不稳定性和湍流产生过程。因此，该项目的结果将改进甚高频雷达观测的几乎所有应用，为科学界以及天气和气候模拟应用带来巨大利益。该项目还将提高对波和驱动整个大气和所有尺度运动的不稳定动力学之间相互作用的定量理解。这将有助于在天气和气候模式中更好地参数化小尺度动力学。

This is a 3-year project to undertake experimental and theoretical studies of Kelvin-Helmholtz Instability (KHI) dynamics and their implications for turbulence and mixing in the Earth atmosphere. KHI is known to occur throughout the lower atmosphere as well as the mesosphere and lower thermosphere (MLT) and to contribute significantly to the dynamics. In addition, KHI evolution affects VHF Doppler radar wind measurement errors by producing strong, persistent layering and a systematic tilting of refractive index surfaces on scales comparable to VHF radar Bragg scales. This project addresses both of these aspects. Observations will be performed at the Jicamarca Radio Observatory (JRO) in Peru, which provides an exceptional combination of sensitivity and resolution throughout the lower atmosphere and the MLT. High range resolution and sensitivity at mid-tropospheric heights provided by the SOUSY Radar (at JRO), coupled with concurrent, quantitative, high-resolution, in situ measurements made using a newly developed unmanned aerial system, named the micro-autonomous vehicle (MAV), will provide an unsurpassed assessment of both high resolution KHI dynamics and radar measurement errors. The relatively high-resolution and higher-power capability provided by the powerful JRO transmitter and large antenna array will then extend the SOUSY results into the MLT. Finally, these observations will be used to initialize a series of numerical assessments of KHI radar backscatter and associated dynamical parameters using a new capability to perform direct numerical simulations (DNS) to characterize, and guide corrections of, measurement errors accompanying these dynamics for general flow conditions.The inaccuracies in radar wind measurements from KHI is a limiting factor in understanding atmospheric dynamics on essentially all scales of motion, including: mean motions, wind shears, large-scale tidal and planetary wave activity, smaller-scale gravity wave dynamics, and small-scale instabilities and turbulence-generating processes. The results from this project, therefore, will improve practically all applications of VHF radar observations to great benefit of the scientific community as well as weather and climate modeling applications. The project also will result in improved quantitative understanding of interactions between waves and instability dynamics that drive motions throughout the atmosphere and at all scales. This will lead to better parameterization of small-scale dynamics in weather and climate models.