Ultrasonic anemometers for in-canopy turbulence research

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My research focuses on atmospheric turbulence close to the Earth's surface. I am a field experimentalist analyzing turbulence in real-world environments especially within canopies and close to rough surfaces (forests, crops, cities, snow). An understanding of atmospheric turbulence close to these surfaces is essential to predict the dispersion of pollutants including toxic releases or objects (e.g. seeds) or to calculate the exchange of trace-gases between Earth's surface and the atmosphere. Often, these rough surfaces are partially porous, and my special interest is to develop and to improve theories of turbulent exchange through these elements and to/from the overlying flow. In my field research I rely on instruments that measure very fast fluctuations of wind and temperature in atmospheric flows. I propose an array of six fast-response sensors that use ultrasound to measure turbulence (ultrasonic-anemometers). I need six sensors to adequately sample the flow because within plant canopies, and close to other rough surfaces, turbulence is very irregular in space. I am particularly interested in these differences (horizontal and vertical gradients) as well as in spatial correlations. Data of this kind will allow valuable insights into the turbulent movement of air at these rough and porous surface-atmosphere interfaces. The instruments can be operated in various configurations e.g. as a vertical profile on a tower, as a horizontal line within a canopy or even as stand-alone instruments deployed over larger distances. This equipment will play a central role in the training of graduate students and will be used in a flexible way in numerous future experiments. Further, as part of a discovery grant I am to develop alternative approaches to track turbulent structures using spatial arrays of fast temperature probes (thermocouple arrays). To validate and complement that approach I will compare the results with those from the requested ultrasonic-anemometer arrays.