CEDAR: Mesospheric Dynamics with Airglow Imaging, Photometry and Meteor Radar

CEDAR：利用气辉成像、光度测量和流星雷达进行中层动力学

• 批准号: 0737656
• 负责人: Alan Liu
• 金额: $ 31.45万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0737656&HistoricalAwards=false
• 关键词: CEDAR; Mesospheric; Dynamics; Airglow; Imaging

Atmospheric Gravity Waves (AGWs) are a major contributor to the dynamics and thermal balance in the mesosphere. This study has several objectives which will address the need for quantitative measurements of AGWs and their signatures in the mesosphere and lower thermosphere. The results will improve understanding of AGW dynamics and help global circulation models to make more accurate simulation of the global climate change with better gravity wave parameterization. Measurements will be carried out using an OH imager, a multi-channel photometer, and a meteor radar. This instrumentation is currently located at Maui, HI and will be re-located to a South American site near Cerro Tololo, Chile (30 S, 71 W). These instruments will be co-located with the University of Illinois Na lidar which will provide high resolution temperature and wind in the same region. The science objectives are: (1) to use OH airglow imagery to measure and study the vertical flux of horizontal momentum carried by AGWs with large vertical wavelengths, which carry the major portion of the wave momentum flux in the mesosphere. The meteor radar will supply wind measurements to be used for Doppler correction of observed phase speeds. The lidar observes slower speed AGWs that complement the spectrum observed in airglow. The direction and magnitude of the fluxes, and their variation with season, will be characterized. Comparisons will be made to similar measurements from other geographic locations and with the intensity and temperature perturbations from the Utah State University Mesospheric Temperature Mapper; (2) to measure and study the vertical propagation direction of short-horizontal-scale AGWs, and to determine the significance of ducted waves in airglow observations. Upward propagating momentum may be cancelled by downward propagating waves, and several investigations have found conditions suggesting ducting may be significant for short horizontal wavelengths. This study will statistically quantify occurrence probabilities for upward/downward propagation, and ducting for waves observed in airglow. The data for this study will be from photometer measurements with high time resolution of the OH molecule which is concentrated in a layer near 86 km and of the O2 atmospheric band, concentrated near 94 km; (3) to understand the large amplitude events observed in airglow images, including "wall waves". Although these events are rare, they may have significant impacts on the atmosphere and the instrument suite will provide geophysical insight into these dramatic events over the South American site. The broader impacts of the project include collaborations with other investigators at the University of Illinois, Utah State, and the Aerospace Corporation. This project will support one graduate student, whose research will comprise the Master's of Science thesis project. Undergraduate students will be involved in the research through participation in independent study projects. Publications and presentations of results will be made throughout the program.

大气重力波（AGWs）是影响中间层动力学和热平衡的主要因素。本研究有几个目标，这些目标将解决对中间层和低层热层中agw及其特征的定量测量需求。研究结果将有助于提高对AGW动力学的认识，并有助于全球环流模式更好地参数化重力波，更准确地模拟全球气候变化。测量将使用OH成像仪、多通道光度计和流星雷达。该仪器目前位于夏威夷的毛伊岛，并将重新定位到智利Cerro Tololo附近的南美站点（南纬30度，西经71度）。这些仪器将与伊利诺伊大学的纳激光雷达一起放置，后者将在同一地区提供高分辨率的温度和风。科学目标是：(1)利用OH气辉图像测量和研究大垂直波长AGWs携带的水平动量垂直通量，这些AGWs携带了中间层波动量通量的主要部分。流星雷达将提供风向测量数据，用于多普勒校正观测到的相位速度。激光雷达观测到的速度较慢的agw与在气辉中观测到的光谱相辅相成。通量的方向和大小，以及它们随季节的变化，将被表征。将与其他地理位置的类似测量结果进行比较，并与犹他州立大学中间层温度成像仪的强度和温度扰动进行比较；(2)测量和研究短水平尺度agw的垂直传播方向，确定导管波在气辉观测中的意义。向上传播的动量可能被向下传播的波抵消，一些研究发现，在短的水平波长下，管道可能很重要。本研究将统计量化在气辉中观测到的波向上/向下传播和导管的发生概率。本研究的数据将来自高时间分辨率的光度计测量，集中在86 km附近的OH分子和集中在94 km附近的O2大气带；(3)了解气辉图像中观测到的大振幅事件，包括“壁波”。虽然这些事件很罕见，但它们可能对大气产生重大影响，仪器套件将为南美地区的这些戏剧性事件提供地球物理学见解。该项目的更广泛影响包括与伊利诺伊大学、犹他州立大学和航空航天公司的其他研究人员的合作。该项目将资助一名研究生，其研究将构成理学硕士论文项目。本科生将通过参与独立研究项目参与研究。出版物和报告结果将贯穿整个项目。