CEDAR: Lower-Upper Atmosphere Coupling via Acoustic Wave Energy

大气区域的耦合、能量学和动力学（CEDAR）项目是一个基础广泛、社区指导的高层大气研究项目，旨在了解从低层大气向上通过中间层和低层热层（MLT）区域80-120公里的大气区域的行为。特别令人感兴趣的是由于与低层大气的耦合而产生的向中间层低层热层（MLT）区域的能量转移，低层大气中存在雷暴、对流锋面活动、龙卷风和其他猛烈风暴天气现象等剧烈现象，以及供暖和空调装置等人为来源，这些都会产生强声波信号。这种能量转移对于MLT能量预算的贡献可能具有重要意义。该合同将为四次（每个季节一次）声波活动的气球飞行测量提供支持，使用仪器零压气球有效载荷飞行到接近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通过声波耗散传播到MLT区域并产生MLT加热的程度。气球麦克风传感器将测量频率在1至10赫兹范围内的声波能量通量。一名博士研究生和一名博士后将获得该奖项的支持。这些观测将在北卡罗来纳大学教堂山校区进行，这将引起公众对这些实验的极大兴趣。每个活动将在早晚两个气球上飞行，每个气球载荷上安装两个麦克风，这些麦克风将获得声波波形数据，这些数据将用于声波结构的射线追踪软件，以确定轨迹、发生率和波频率。这些测量将在四个单独的活动中获得，以测量声能背景的季节和日变化。确定对MLT区域可能产生的影响将基于线性声波吸收理论的应用，遵循先前发表的工作路线。对于人为来源（例如空调系统）可能产生的复杂声波形式，将对分析进行更复杂的处理，以定量方式确定对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.