Studies of High-Resolution Turbulence, Stratification, and Instabilities in the Nighttime Boundary Layer

作为CASE-99计划(1999年合作大气-地面交换研究)的一部分，PI使用悬挂在系绳风筝上的仪器或在平静条件下的系绳气球上的仪器，以高分辨率测量时间和高度的温度、压力、湿度和风速。对数据的初步分析揭示了急剧的逆温、间歇性的湍流爆发和明显的波动现象，所有这些都具有前所未有的分辨率。这笔赠款支持对Case-99数据的持续分析。分析主要集中在以下几个方面：(1)选定的均匀层中湍流的统计特征；(2)不同湍流特征层之间水平界面附近的湍流研究；(3)湍流间歇性的研究，包括能量耗散率e谱和温度结构参数ct2的计算；(4)与大涡模拟模式合作，考察Kelvin-Helmholtz不稳定性的结构和其他波动现象；(5)与CASES-99研究人员在不同数据集的分析方面进行了其他合作。这项研究促进了对大气湍流的基本理解，并使夜间大气边界层中热量、动量和物质的扩散和垂直输送的参数化得到改进。

As part of the CASES-99 program (Cooperative Atmosphere-Surface Exchange Study-1999), the PI measured the temperature, pressure, humidity, and wind velocity with high resolution in time and altitude using instruments suspended from a tethered kite or, in calm conditions, a tethered blimp. Preliminary analysis of the data has revealed sharp temperature inversions, intermittent bursts of turbulence, and apparent wave phenomena, all with unprecedented resolution. This grant supports the continuing analysis of CASES-99 data. The analysis is focused on the following objectives:(1) statistical characterization of the turbulence in selected homogeneous layers;(2) investigation of turbulence in the vicinity of horizontal interfaces separating layers with different turbulence characteristics;(3) study of turbulence intermittence, including calculation of spectra of the energy dissipation rate e and the temperature structure parameter Ct2;(4) examination of the structure of Kelvin-Helmholtz instabilities and other wave phenomena in collaboration with large-eddy simulation modelers;(5) entering other collaborations with CASES-99 researchers in the analysis of different data sets.This research advances the fundamental understanding of atmospheric turbulence and enables improved parameterization of the diffusion and vertical transport of heat, momentum, and material in the nocturnal atmospheric boundary layer.