CEDAR: Lower-Upper Atmosphere Coupling via Acoustic Wave Energy

大气区域耦合、能量和动力学(CEDAR)计划是一个基础广泛的、社区指导的高层大气研究计划，旨在了解从低层大气向上穿过中层和近80-120公里的热层下层(MLT)区域的大气行为。特别令人感兴趣的是，由于耦合到低层大气，能量转移到中间层低热层(MLT)区域，在低层大气中有雷暴、对流锋面活动、龙卷风和其他强烈风暴天气现象，以及将产生强烈声波信号的人为来源，如供暖和空调装置。这种能量转移可能对MLT能源预算的贡献具有重要意义。该奖项为四次声波活动(每个季节一次)的气球飞行测量提供支持，使用仪表零压力气球有效载荷飞行到近35公里的平流层高度。该项目旨在确定对流层内产生的声波结构将在多大程度上传播到MLT区域，并通过声波消散产生MLT加热。气球传声器传感器将在1至10赫兹的频率范围内测量声波能量通量。这一奖项将支持一名博士研究生和一名博士后助理。这些观察将在北卡罗来纳大学教堂山校区发射，这将引起公众对这些实验的极大兴趣。每一次战役的特点是两个气球在早晨和晚上飞行，每个气球携带两个麦克风，安装在每个气球有效载荷中，这些气球将获得声波波形数据，这些数据将用于声波结构的射线跟踪软件，以确定轨迹、出现率和波频率。这些测量将在四个不同的活动中获得，以测量声学能量背景的季节和日变化。对MLT区域的可能影响的确定将基于线性声波吸收理论的应用，遵循先前发表的工作的思路。在人为来源(例如空调系统)可能产生的复杂声音波形的情况下，将对分析进行更复杂的处理，以定量确定对MLT温度的影响。

The Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) program, a broad-based, community-guided, upper atmospheric research program, is aimed at understanding the behavior of atmospheric regions from the lower atmosphere upward through the mesosphere and lower thermosphere (MLT) region near 80-120 km. Of particular interest is the energy transfer into the mesosphere lower thermosphere (MLT) region resulting from the coupling to the lower atmosphere, where there are violent phenomena such as thunderstorms, convective frontal activity, tornados, and other violent storm weather phenomena, as well as anthropogenic sources such as heating and air conditioning units, that will produce strong acoustic wave signals. Such energy transfer might have importance regarding a contribution to the MLT energy budget. This award provides support for the balloon flight measurements over four campaigns (one for each season) of acoustic wave activity using instrumented zero pressure balloon payloads flown to stratosphere heights near 35 km. The project is aimed at establishing the extent to which acoustic wave structures generated within the troposphere will propagate to the MLT region and produce MLT heating through acoustic wave dissipation. The balloon microphone sensors would measure the acoustic wave energy flux for frequencies within the range of 1 to 10 Hz. A PhD graduate student and a postdoctoral associate would be supported in this award.These observations would take place with launches from the University of North Carolina Chapel Hill campus, which will create considerable public interest in these experiments. Each campaign would feature morning and evening flights of two balloons carrying aloft two microphones mounted in each balloon payload that would obtained acoustic waveform data that would be used in ray tracing software of acoustic wave structures to determine trajactories, occurrence rates, and wave frequency. These measurements would be obtained in four separate campaigns to measure the seasonal and diurnal variation of the aooustic energy background. Determination of the possible effects upon the MLT region would be based upon the application of linear sound wave absorption theory following the lines of previous published work. In the case of possible complex sound waveforms as might be generated by anthropogenic sources (e.g., air conditioning systems, a more sophisticated treatment of the analysis would be carried out to determine the impact upon the MLT temperature in a quantitative way.