CEDAR: Lower-Upper Atmosphere Coupling via Acoustic Wave Energy

CEDAR：通过声波能进行上下大气耦合

• 批准号: 1551999
• 负责人: Jonathan Lees
• 金额: $ 17.63万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1551999&HistoricalAwards=false
• 关键词: CEDAR; Lower; Upper; Atmosphere; Coupling

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.

大气区域耦合、能量学和动力学（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到80-120公里附近的中间层和低热层（MLT）区域的大气区域的行为。特别令人感兴趣的是，由于与低层大气的耦合，能量转移到中间层低热层（MLT）区域，那里有雷暴，对流锋面活动，龙卷风和其他猛烈的风暴天气现象，以及人为源，如加热和空调装置，这将产生强烈的声波信号。这种能量转移可能对MLT能量预算的贡献具有重要性。该奖项为气球飞行测量提供了支持，这些气球飞行测量超过四个活动（每个季节一个），使用飞行到35公里附近平流层高度的仪表零压气球有效载荷进行声波活动。该项目旨在确定对流层内产生的声波结构传播到MLT区域并通过声波耗散产生MLT加热的程度。气球麦克风传感器将测量1至10 Hz范围内的频率的声波能量通量。 该奖项将资助一名博士研究生和一名博士后研究员。这些观测将在北卡罗来纳州查佩尔山大学校园的发射中进行，这将引起公众对这些实验的极大兴趣。每个活动将以两个气球的早晨和晚上飞行为特色，每个气球有效载荷中安装有两个麦克风，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跟踪软件中，以确定轨迹，发生率和波频率。这些测量将在四个独立的运动中获得，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，该理论遵循先前发表的工作。在可能由人为源产生的可能的复杂声音波形的情况下（例如，空调系统，将进行更复杂的分析处理，以定量的方式确定对MLT温度的影响。