Weak-wind flows in plant canopies
Advanced Resolution Canopy FLow Observations (ARCFLO)
National Science Foundation, CAREER Award 0955444
The project will study how air moves in plant canopies such as crops and forests where winds are usually relatively weak, and how it affects the transport of heat, water, and momentum. The research component includes new field observations across a large spectrum of sites with contrasting characteristics of canopy architecure and terrain including the OSU Botany & Plant Pathology Field lab, the HJ Andrews Experimental forest, and two AmeriFlux Sites in Oregon. The findings from this unique set of experiments will be the key step toward the long-term goal to develop a novel improved framework to describe the flow and its transport under weak-wind conditions for a continuous variation of overstory density and stratification. Observations will be made with a unique combination of new and classic micrometeorological techniques including optical fiber measurement of temperature structure (DTS), acoustic remote sensing (SODAR), ultrasonic anemometers, thermo-/ hygrometers, and laser-illuminated flow visualizations as illustrated in the schematic experimental setup.
Background, broader impacts
The level of scientific understanding of weak-wind transport is very limited, and commonly used forecast tools and mathematical formulations don't apply. This information is also needed to correctly predict the spread of pollutants or contaminants in nocturnal atmospheric conditions, and to more precisely estimate carbon sequestration and evapotranspiration rates from tall vegetation. The broader impacts of the project are improved formulations of surface fluxes for regional and large-scale weather and climate models, as well as dispersion and diffusion models. A set of practical recommendations for the applied flux community will be formulated to reduce uncertainties in carbon and energy budgets, and to better predict the water availability in forests. In addition to a graduate student, an Oregon K-12 high school teacher will be working with the PI through a partnership with the Oregon Natural Resources Education Program at OSU. The PI will also work with the Willamette National Forest to improve management decisions for fire fighting.