Biometeorology and Micrometeorology
The gondola at the Wind River Canopy Crane Reasearch Facility, used to carry researchers into the canopy.
The Biometeorology program at Davis is concerned with the physical processes that govern exchanges between biological surfaces and the lower atmosphere. Such exchanges include momentum, sensible heat and water vapor, and various gases and particulate matter for both individual organisms and communities. Students in this specialty participate in modeling, observation and theoretical studies of these exchanges, with special emphasis upon the turbulent nature of the atmospheric surface layer.
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Ian Faloona
seeks to develop research spanning the gaps between atmospheric chemistry and turbulent exchange dynamics. He is interested in developing a novel laser spectroscopic technique to measure halogen gases (e.g., HCl) in the atmosphere, yet the ultimate objective is to use the data to learn about both the chemical reactions of the atmosphere as well as the mixing processes which strongly control the ability of compounds to react with one another. Specific current research includes direct eddy-correlation measurements of carbon monoxide (CO) from a coastal marine ecosystem, mixing studies of dimethyl sulfide (DMS) in the stratocumulus topped marine boundary layer, and measurements of formaldehyde (HCHO), an important byproduct of biogenic hydrocarbon oxidation, in a Pine forest in the Sierras.
Kyaw Tha Paw U
studies the physical and biometeorological processes responsible for exchanges of momentum, heat, and gases such as water vapor between the lower atmosphere and vegetated surfaces. These processes are fundamental to understanding how forests, for example, absorb pollutant gases, how agricultural crops utilize water, and how plant communities exchange carbon dioxide with the atmosphere. The plant biometeorology research encompasses experimental observation in the field, numerical modeling, and theoretical analysis of turbulent mechanisms in and above plant communities. Experiments involve using fast response instruments to measure turbulence, such as sonic anemometers and infrared gas analyzers (IRGAs). Current projects include estimating turbulent parameters and dispersion coefficients for a California regional air quality study, and determining, by eddy-covariance and mean advection methods, and the carbon exchange between the atmosphere and a 500-year old, 65 m high forest at the Wind River Canopy Crane Research facility (WRCCRF). Our research group is measuring carbon dioxide fluxes, and is in collaboration with a group measuring biogenic hydrocarbon emissions from the forest canopy. Recent data indicated this old-growth forest is surprising active and is annually sequestering approximately 2 tons of carbon per hectare, similar to younger forests. Other areas of research focus on the observation and analysis of repeatable patterns in the turbulent wind fields. These characteristic motions, or coherent structures, appear to play an important role in the overall exchange process. Numerical modeling work involves two main topics, the first being state-of-the-art Large Eddy Simulation (LES) of turbulence within and above plan canopies, using the NCAR supercomputer system. The second topic is the numerical modeling of plant canopies using higher-order closure turbulence equations linked with radiation, energy budget, and plant physiology models. This set of models has been named the "Advanced Canopy-Atmosphere Simulation Algorithm" (ACASA). It has been connected to the regional scale model MM5 and can provide a regional scale understanding of ecosystem-atmosphere interactions of radiation, the energy balance, carbon, water, other gaseous and particulate emissions, transport, and deposition. In addition, Professor Paw U has studied the thermal budget of animals and humans in response to atmospheric variables.
Richard Snyder
is a Cooperative Extension Biometeorologist whose research focuses on the measurements, the dissemination, and the interpretation of meteorological data for use in a biological context. His interests include soil-plant- atmosphere relationships, agricultural climatology, frost protection theory and practice, and irrigation practices as influenced by the weather.