BEACHON

BEACHON is an NCAR cross-laboratory program with the goal of improving predictability of Earth system behavior based on better measurements and understanding of the coupling between water, energy, and biogeochemical cycles; and to expand the range of societal-environmental options available to policy and decision makers. To support this goal, BEACHON research focuses on the following

  1. Understand and quantify the fundamental ecological, hydrological, and atmospheric processes associated with land ecosystem-atmosphere interactions including the response to disturbances (e.g., drying, warming, and insect outbreaks).
  2. Advance world-leading numerical models of land ecosystem-atmosphere interactions, including atmospheric oxidation and aerosol/cloud processes, make them widely available, and support their use by the scientific community.
  3. Develop and provide state of the art observational facilities and approaches required to quantify land ecosystem-atmosphere interactions, including atmospheric oxidation and aerosol/cloud processes, and make these approaches available to the scientific community.
  4. Lead integrated regional studies (aircraft, satellite, and regional network observations and regional modeling) to develop a comprehensive knowledge system designed to analyze and predict bio-hydro-atmosphere interactions and feedbacks and the impacts of disturbances at the regional scale.

The NCAR-BEACHON Manitou Forest Observatory (MFO) is a key component of BEACHON efforts to develop and provide state-of-the-art observational facilities. The observatory is located on a US Forest Service experimental forest near Woodland Park, Colorado that is representative of the semi-arid Western U.S., where biosphere-atmosphere exchange processes are particularly sensitive to changes in water availability.  The site is one of only a few in the world with continuous measurements of biosphere-atmosphere exchange processes of energy, water, carbon, reactive gases, and aerosols along the with the meteorological, hydrological, and ecological variables that control these exchanges. BEACHON hosts intensive field campaigns that bring from 20 to 60 university and international investigators to the site each year. An August 2010 field campaign at MFO brought participants from NCAR, US Forest Service, US EPA, University of Wisconsin, Stonybrook University, University of Colorado, Colorado State, Colorado College, U. Innsbruck (Austria), and Tokyo Metro. University (Japan) and successfully obtained a comprehensive suite of measurements of biogenic VOC (volatile organic compounds) emissions, oxidation products, and oxidants. 

An example of BEACHON’s success in integrating biological, chemical, and physical process understanding with multi-scale (leaf, canopy, regional/global) measurements and modeling is the investigation of efficient uptake of atmospheric organics by plants. VOCs fuel tropospheric chemistry and are a critical component for understanding radical cycling as well as ozone and organic aerosol formation. Biogenic sources are thought to dominate the global VOC budget (i.e. 80-90%).  The fraction of low to moderately soluble VOC depositing back to vegetation currently remains practically unknown. This represents a significant uncertainty when constraining budgets of VOC (and subsequently organic aerosol), because these VOCs account for a large amount of carbon during the initial oxidation phase. BEACHON scientists analyzed a large number of canopy-scale micrometeorological field observations and have shown that the removal of oxygenated volatile organic compounds (oVOCs) via dry deposition is substantially larger than currently assumed for deciduous ecosystems (temperate, sub-tropical and tropical).  Leaf-level laboratory experiments were conducted to identify detoxification mechanisms that explain these observations. These laboratory experiments also suggest that chemical stresses (e.g. elevated ozone levels) can potentially increase the uptake of oVOC via short (0-2 hours) and long-term (>1day) genetic upregulation of enzymes controlling detoxification. Incorporation of a modified dry deposition scheme into the NCAR MOZART (model of ozone and related trace species) global chemistry model leads to appreciable regional increases of predicted dry deposition. These results were published in the Nov. 2010 issue of Science (Karl et al. DOI: 10.1126/science.1192534 ) and have important consequences for capturing the dynamic behavior and repartitioning of organic carbon (VOC+SVOC+SOA) in coupled Earth-system models.