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

作为CASES-99计划（1999年大气-地表交换合作研究）的一部分，PI使用悬挂在系留风筝上的仪器或在平静条件下悬挂在系留飞艇上的仪器测量了温度，压力，湿度和风速。 对数据的初步分析揭示了急剧的温度逆温、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。 这笔赠款用于继续分析CASES-99的数据。 分析的主要目的是：（1）对选定的均匀层中湍流的统计特性进行研究;（2）对具有不同湍流特性的层间水平界面附近的湍流进行研究;（3）研究湍流的不稳定性，包括计算能量耗散率e和温度结构参数Ct ~ 2的谱;（4）与大涡模拟模型制作者合作，检查开尔文-亥姆霍兹不稳定性的结构和其他波动现象;（5）与CASES进行其他合作-99名研究人员对不同的数据集进行了分析。这项研究推进了对大气湍流的基本理解，并改进了扩散和垂直方向的参数化。夜间大气边界层中热量、动量和物质的输送。

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.