This work will focus on a closely coordinated observational and numerical study of wind structure in the lowest layers of the atmosphere, with particular attention to mechanisms leading to development of a recurring wind pattern known as the "low level jet" (as in jetstream, aka LLJ, which frequently develops during nighttime hours over the U.S. central plains during spring/summer months). Particular attention will be directed toward identifying environmental controls on the degree to which this elevated source of momentum (and hence energy) is mixed down toward the earth's surface and its subsequent impacts on renewable energy production via wind turbines. The investigator's approach will embody a combination of: (1) development of an expanded observational database describing LLJ structure via an array of existing facilities operated by Texas Tech (including a 200 m tower mounted with sonic anemometers at 10 discrete levels) in conjunction with a newly acquired scintillometer--all of which are key to better understanding near-surface wind profile evolution under LLJ conditions; (2) numerical simulations to quantify turbulent controls on the intermittent vertical mixing of momentum from the level of the LLJ down to that of wind turbines during stably-stratified conditions typical of nighttime; (3) development of a new graduate-level course at Texas Tech University entitled "Wind Power Meteorology"; and (4) a broad K-12 outreach effort exposing teachers and students at local schools to a variety of classroom and field activities that will significantly enhance both primary and secondary science education.
A particularly novel aspect of this project is inclusion of the "Large Eddy Simulation" (LES) approach in tandem with more traditional mesoscale simulations conducted via the Weather Forecasting Model (WRF). This effort, in tandem with above-mentioned special observations, will better describe the occurrence (and ultimately serve to achieve more accurate prediction) of episodes of turbulence in which stronger winds rooted aloft in the core of the LLJ mix downward toward the surface.
The Broader Impacts of this work are substantial, and will include more accurate forecasts of changes in urban air quality and power generation capacity across large networks of turbine-powered electric generators ("wind farms") whose implementation is expanding rapidly in this era of mounting petroleum prices. Considerable enhancements to education at primary, secondary and university level will also occur as students are exposed to various aspects of the observation and numerical forecast of near-surface winds through suitable data visualization techniques (in the classroom) and field trips to become more familiar with renewable energy generation systems.
Energy production is one of the critical issues facing the United States of America and the world. Fortunately, the renewable energy research and industry in the U.S. has witnessed a significant surge in recent years. The research component of this project focused on an atmospheric phenomenon, known as the nocturnal low-level jet (LLJ), which has direct ramifications for renewable energy generation. The nocturnal LLJs are common features over the Great Plains and coastal regions of the U.S., and provide a vast resource of wind energy. In order harness this energy in efficient and cost-effective manner, advanced micro/mesoscale modeling tools are needed. During this CAREER project, the PI’s team worked on various interrelated research areas to improve our capabilities to model LLJs. They: developed new modeling framework and performed cutting-edge simulations of LLJs; created new as well as revised physics parameterizations; conducted several field experiments to better characterize turbulence during LLJs; simulated so-called turbulent bursting events; generated unparalleled modeled databases of LLJs; etc. All the research findings have been disseminated via peer-reviewed publications, graduate student theses/dissertations, and numerous conference presentations and posters. From publication perspective, the PIs team targeted diverse audience ranging from wind industry community (e.g., Energies, Wind Energy journals) to boundary layer turbulence community (e.g., Boundary-Layer Meteorology journal). The education and outreach element of this project was focused on educating the graduate students in the relatively new and multidisciplinary field of Wind Power Meteorology, enhancing renewable energy awareness among the K-12 community, and bridging the gap between the academia and the wind energy industry. The PI: collaborated with middle school science teachers to produce lesson plans; co-directed and participated in three summer camps on wind energy; developed a new graduate course on Wind Power Meteorology; delivered lectures to K-12 students and teachers; co-convened scientific sessions at international conferences; build website for the dissemination of wind data and information to the public; crafted internship opportunities for graduate students in the wind energy industry; etc.
