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2nd Quarter, 2013 TOT Comments
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Review of Quarterly Report by Technical Oversight Team
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Quarterly Reports
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Q2 2013
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A large source of low-volatility secondary organic aerosol
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Forests emit large quantities of volatile organic compounds (VOCs) to the atmosphere. Their condensable oxidation products can form secondary organic aerosol, a significant and ubiquitous component of atmospheric aerosol 1,2, which is known to affect the Earth’s radiation balance by scattering solar radiation and by acting as cloud condensation nuclei 3. The quantitative assessment of such climate effects remains hampered by a number of factors, including an incom- plete understanding of how biogenic VOCs contribute to the formation of atmospheric secondary organic aerosol. The growth of newly formed particles from sizes of less than three nanometres up to the sizes of cloud condensation nuclei (about one hundred nanometres) in many continental ecosystems requires abundant, essentially non- volatile organic vapours4–6, but the sources and compositions of such vapours remain unknown. Here we investigate the oxidation of VOCs, in particular the terpene a-pinene, under atmospherically relevant conditions in chamber experiments. We find that a direct pathway leads from several biogenic VOCs, such as monoterpenes, to the for- mation of large amounts of extremely low-volatility vapours. These vapours form at significant mass yield in the gas phase and condense irreversibly onto aerosol surfaces to produce secondary organic aero- sol, helping to explain the discrepancy between the observed atmo- spheric burden of secondary organic aerosol and that reported by many model studies2. We further demonstrate how these low-volatility vapours can enhance, or even dominate, the formation and growth of aerosol particles over forested regions, providing a missing link between biogenic VOCs and their conversion to aerosol particles. Our findings could help to improve assessments of biosphere–aerosol– climate feedback mechanisms 6–8, and the air quality and climate effects of biogenic emissions generally.
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Climate Science Documents
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Abstract and Progress Report for Q3 2012
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Abstract and progress report from the Vendor for the Ecological Flows Project.
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Quarterly Reports
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Q3 2012
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Appalachian LCC Funds Four Landscape-level Projects
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The Appalachian Landscape Conservation Cooperative (LCC) is investing in conservation projects across the Appalachian region that will support the sustainable management of resources and develop tools and information for conservation delivery.
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News & Events
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Aquatic Ecological Flows Phase 1 Report
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The 1st phase of the Aquatic Ecological Flows project involved reviewing existing tools and gathering available data within the project area on hydrologic and ecological flow model(s) that would be suitable for the region. This Report details that work.
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Deliverables
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Aquatic Ecological Flows Project Update
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This presentation from Dr. Todd Walter of Cornell University provides an update to the Steering Committee on the Appalachian LCC funded research project. The Aquatic Ecological Flows project is providing a report assessing availability of hydrologic and ecological flow model(s) suitable for the region, a georeference assessment of available ecological data to inform the ecological flow model(s), the application of the model(s) to anticipate how altered flow regimes will affect critical conditions, and a report that forecasts changes in hydrology and associated predicted biological responses in relation to different water resource development scenarios for critical watersheds.
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Past SC Meetings and Materials
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Steering Committee Call 3/6/14
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Biophysical controls on organic carbon fluxes in fluvial networks.pdf
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Metabolism of terrestrial organic carbon in freshwater ecosystems is responsible for a large amount of carbon dioxide outgassing to the atmosphere, in contradiction to the conventional wisdom that terrestrial organic carbon is recalcitrant and contributes little to the support of aquatic metabolism. Here, we combine recent findings from geophysics, microbial ecology and organic geochemistry to show geophysical opportunity and microbial capacity to enhance the net heterotrophy in streams, rivers and estuaries. We identify hydrological storage and retention zones that extend the residence time of organic carbon during downstream transport as geophysical opportunities for microorganisms to develop as attached biofilms or suspended aggregates, and to metabolize organic carbon for energy and growth. We consider fluvial networks as meta-ecosystems to include the acclimation of microbial communities in downstream ecosystems that enable them to exploit energy that escapes from upstream ecosystems, thereby increasing the overall energy utilization at the network level.
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Climate Science Documents
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Carbon in idle croplands
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The collapse of the Soviet Union had diverse consequences, not least the abandonment of crop cultivation in many areas. One result has been the vast accumulation of soil organic carbon in the areas affected.
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Climate Science Documents
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Curran, Joanna
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Expertise Search
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Ecological Flows 2nd Quarter Report, 2013
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Report from Vendors of the Aquatic Ecologic Flows Project.
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Quarterly Reports
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Q2 2013
