The study aims to identify and quantify linkages between the biogenesis of aerosols that can function as cloud nuclei and the feedback through altered precipitation patterns on vegetation processes that generate more aerosols. The approach combines experiments, field measurements and laboratory investigations. Each represents a key component of the overall cycle: 1) surveys of important sources of biogenic volatile organic compounds along a broad transect of sites in the Southwestern U.S.; 2) atmospheric surveys of biological aerosol particles, which will take place at one of the sites and include the interesting idea of DNA sequencing of particles to identify their sources; 3) two field studies to manipulate water and investigate impacts on vegetation, one involving imposition of drought in individual ponderosa pine trees and an investigation of their VOC emissions and the other on a separate (but nearby) set of plots to impose different moisture regimes to quantify the impact of moisture on soil/litter VOC emissions; 4) studies of biogenic ice nuclei and cloud condensation nuclei. These four investigations will be linked together in a fifth activity involving a model: Model of Emissions of Gases and Aerosols from Nature (MEGAN).
One of the principal broader impacts of this work will occur through the improvement of a coupled surface-atmosphere model that is available to the broader scientific community from the National Center for Atmospheric Research (NCAR) web site, and is capable of supporting future studies involving plant-cloud interactions. The project will also support diversity in science initiatives at NCAR and the University of Colorado by involving at least six underrepresented-group undergraduate students in the research project. To extend the impact of project into the public sector and the K-12 community, web-based educational materials will be developed that will explain the impact of climate change on the forest ecosystem, and will include real-time data from the Manitou Forest Observatory. Ultimately, the results will lead to new strategies for assessing the impact of regional climate change on ecosystems in the Western U.S. and managing those impacts through recognition of the role ecosystems play in amplifying or dampening further climate change.
