Microfronts 1995 and Cases 1999: Boundary Layer Influences on Fronts and Inertial Oscillations

微锋 1995 和案例 1999：边界层对锋和惯性振荡的影响

• 批准号: 9903645
• 负责人: Julie Lundquist
• 金额: $ 32.02万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2004-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9903645&HistoricalAwards=false
• 关键词: Microfronts; 1995; Cases; 1999; Boundary

Processes that occur in the Earth's boundary layer, the relatively shallow layer in contact with the ground, often have a significant effect on atmospheric fronts and are a source of wave motions and atmospheric oscillations. Data available from a previous field investigation in Kansas in 1995 (MICROFRONTS) consists of high frequency hot-wire anemometer winds and both wind and temperature from sonic anemometers mounted on 10 meter tower arrays. Three frontal passages occurred when the instruments were operative. These data, and other lower frequency observations, will continue to be analyzed to determine the kinetic energy dissipation rate and turbulence characteristics that characterize fronts. These motions occur on subgrid spatial and temporal scales of numerical atmospheric models. The turbulent dissipative contributions are either not prescribed or handled ineffectively by all or most models. The present aim is to provide the necessary data analysis and theoretical understanding that is required to ultimately parameterize turbulent dissipation associated with fronts.The passage of fronts and the relatively abrupt change in the height of the boundary layer near sunset appear to be sources for the initiation of internal gravity waves and inertial oscillations. Four years of data from the National Oceanic and Atmospheric Administration wind profiler network, and from three profilers maintained in Kansas by the Argonne National Laboratory, will be analyzed by the rotary spectrum technique. The purpose is to extract properties of atmospheric inertial oscillations, and to develop boundary layer models that will establish the relative importance of fronts and boundary layer depth changes in their occurrence. The role of these oscillations on the dynamics of fronts will continue to be investigated by use of frontogenesis models. The source and characteristics of these oscillations has also been recognized as important for long-range modeling of atmospheric dispersion. Ongoing model development for this purpose is of considerable importance in the prediction of urban air quality.The current data bases will be expanded by participation in a field program to be carried out in southern Kansas in October 1999 (Cooperative Atmosphere-Surface Exchange Study -- 1999). These data will be used with ongoing model developments to both improve and to verify model predictions. The observational arrays are expected to be suitable to acquire data that is required to isolate boundary layer sources for both inertial oscillations and for internal gravity waves.

在地球边界层（与地面接触的相对较浅的一层）中发生的过程往往对大气锋面产生重大影响，并且是波动和大气振荡的来源。 1995年在堪萨斯进行的一次现场调查（MICROFRONTS）中获得的数据包括高频热线风速计风和安装在10米塔架阵列上的声波风速计的风和温度。 三个额叶通道发生时，仪器的操作。 将继续分析这些数据和其他低频观测数据，以确定表征锋面的动能耗散率和湍流特征。 这些运动发生在数值大气模式的亚网格时空尺度上。 所有或大多数模型都没有规定湍流耗散贡献，或者处理不力。 目前的目的是提供必要的数据分析和理论的理解，这是需要最终parameterized湍流耗散与fronts.The通过的前和相对突然的变化，在接近日落的边界层的高度出现的内部重力波和惯性振荡的启动源。将用旋转光谱技术分析来自国家海洋和大气管理局风廓线仪网络和阿贡国家实验室在堪萨斯维护的三个风廓线仪的四年数据。 目的是提取大气惯性振荡的特性，并建立边界层模型，以确定锋面和边界层深度变化在其发生时的相对重要性。 这些振荡对锋面动力学的作用将继续通过使用锋生模式进行研究。 这些振荡的来源和特征也被认为对大气弥散的长期模拟很重要。 为此目的正在进行的模式发展在预测城市空气质量方面相当重要，目前的数据库将通过参加1999年10月在堪萨斯南部执行的一个实地方案而扩大（合作大气-地面交换研究- 1999年）。这些数据将用于正在进行的模型开发，以改进和验证模型预测。 预计观测阵列将适合于获取隔离惯性振荡和重力内波边界层源所需的数据。