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

合作研究：利用 JRO 和超高分辨率 DNS 的雷达观测和原位测量来量化 KHI、湍流过程和雷达偏差

• 批准号: 1041977
• 负责人: David Fritts
• 金额: $ 28.5万
• 依托单位: NorthWest Research Associates, Incorporated
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2012-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1041977&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; KHI; Turbulence

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.

这是一个为期3年的项目，旨在进行开尔文 - 霍尔姆兹不稳定性（KHI）动力学及其对地球大气中湍流和混合的影响的实验和理论研究。众所周知，KHI发生在整个下部大气层以及中层和较低的热层（MLT），并对动态产生显着贡献。 此外，KHI进化会通过产生强，持续的分层和与VHF雷达bragg量表相当的尺度上的折射率表面的系统倾斜来影响VHF多普勒雷达风测量误差。 该项目解决了这两个方面。 观测将在秘鲁的Jicamarca无线电天文台（JRO）上进行，该观测值在整个大气层和MLT中提供了敏感性和分辨率的特殊组合。在Sousy雷达（在JRO上）提供的高距离分辨率和敏感性，再加上并发，定量的，高分辨率，使用新开发的无人驾驶系统制造的原位测量值，名为微型自主车（MAV），将提供无效的评估量的高分辨率KHI量和范围，并提供了高分辨率的范围。然后，强大的JRO发射器和大型天线阵列提供的相对高分辨率和高功率将将Sousy结果扩展到MLT。最后，这些观察结果将用于初始化一系列对KHI雷达反向散射和相关的动态参数的数值评估，使用新的能力来执行直接数值模拟（DNS）来表征和指导校正，指导对这些动态的测量误差，从而在整体上进行整体动力学的动态。包括：平均运动，风剪，大规模的潮汐和行星波活动，较小的重力波动力学以及小规模的不稳定性以及生成湍流的过程。因此，该项目的结果实际上将改善VHF雷达观察的所有应用，从而使科学界以及天气和气候建模应用的巨大好处。 该项目还将改善对波动和不稳定动力的不稳定动力学之间相互作用的定量理解，这些动力驱动整个大气和各个尺度的动力。这将导致在天气和气候模型中更好地参数化小型动态。