CAREER: Towards a Better Understanding of Turbulence Structures in a Disturbed Atmospheric Surface Layer

点击翻译按钮获取中文摘要

The Monin-Obukhov similarity theory (MOST) provides numerical weather and climate models with a basis in formulating the turbulent exchange of momentum, energy, water vapor, and other scalars between the Earth's surface and the lower atmosphere. However, several recent studies have identified some features that are not fully consistent with predictions by MOST and attributed these departures to the disturbance of outer-layer, large-scale coherent structures (hereafter referred to as coherent eddies) on locally-generated active turbulence in the atmospheric surface layer (ASL). Although some studies have presented alternative theories to describe these discrepancies, turbulence structures in the disturbed ASL are still poorly understood. The objectives of this project are to study turbulence structures in the stable and unstable ASL beneath a convective boundary layer where a strong interaction between coherent eddies and active turbulence occurs. The datasets from the already completed Energy Balance Experiment will be used. More specifically, this project aims to: 1. Quantify turbulence structures under the influence of large-scale coherent eddies and characterize the deviations of turbulence structures from predictions by MOST under two atmospheric stratifications during the daytime in the disturbed ASL. 2. Investigate how coherent eddies interact with the ASL turbulence and their contributions to flux exchange of momentum, heat, and water vapor under two atmospheric stratifications. 3. Study the spatial structures and temporal evolutions of coherent eddies from time-series data in the ASL to elucidate the origins and sources of coherent eddies. 4. Enhance the Jackson State University Micrometeorology Laboratory and enrich meteorological courses through incorporating research activities and findings of this project in the classroom and teaching laboratories. 5. Involve a large number of African American undergraduate and graduate students and encourage them to take part in the research activities. This program will provide an excellent education and training opportunity for undergraduate and graduate students and will greatly enhance atmospheric sciences education in Jackson State University, one of the nation's largest historically black colleges and universities.