This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
The ability of a scanning eye-safe aerosol lidar to measure the horizontal vector wind field in the atmospheric surface layer will be quantitatively evaluated. This will be done by calculating spatial correlation functions from elastic backscatter lidar scan images displaced in time. This method capitalizes on the wind-induced motion of aerosol features in the lidar?s scan imagery. The primary hypothesis is that the correlation technique will perform well during periods of sufficient turbulence intensity and may fail during periods of strong stability. The hypothesis will be tested by comparing how well the wind vectors from the lidar and in situ anemometers located within the scanned region agree as a function of turbulence intensity and stability as measured by the instrumentation on a tower within the scanned region.
In addition to testing the above hypothesis, the techniques refined and evaluated in the first part of the project will then be used for a comprehensive search for statistical relationships between perturbations in the lidar backscatter intensity data and turbulence variables measured in situ on the tower. The result will be a better understanding of the spatial distribution and evolution of phenomena such as turbulent coherent structures, fine-scale gravity waves, and the interplay between turbulence and waves during stable conditions. The processed data set, in the form of images and animations of backscatter and wind fields, will be made publicly available on a website.
This research will have several broader impacts. It will form the nucleus of a new interdisciplinary research and education program at the California State University, Chico, where the NCAR REAL resides on long-term loan. Students from a variety of disciplines including physics, computer science, engineering, agriculture and health sciences will benefit from participation in this program. The lidar system and wind measurement capability will be available for other investigators and students to use as new applications for the system develop. The lidar system will be useful wherever there is a need to monitor and predict the dispersion of particulate or hazardous material in the atmosphere. Potential applications include: monitoring the air-shed around air quality sensors; tracking and predicting the dispersion of hazardous material in the atmosphere including releases from chemical and nuclear power plants; monitoring fugitive dust from mining operations; monitoring the application of pesticides over large agricultural areas; monitoring the emissions from agricultural sites such as intensive piggeries; monitoring smoke plumes from agricultural operations such as burning off rice and sugar cane fields; early warning of wildfires and predicting the speed and direction of the fire movement; and monitoring the plumes from industrial sites such as smelters and coal-fired power plants.
