The pursuit of isotopic and molecular fire tracers in the polar atmosphere and cryosphere

We present an overview of recent multidisciplinary, multi-institutional efforts to identify and date major sources of combustion aerosol in the current and paleoatmospheres. The work was stimulated, in part, by an atmospheric particle \u27sample of opportunity\u27 collected at Summit, Greenland in August 1994, that bore the 14C imprint of biomass burning. During the summer field seasons of 1995 and 1996, we collected air filter, surface snow and snowpit samples to investigate chemical and isotopic evidence of combustion particles that had been transported from distant fires. Among the chemical tracers employed for source identification are organic acids, potassium and ammonium ions, and elemental and organic components of carbonaceous particles. Ion chromatography, performed by members of the Climate Change Research Center (University of New Hampshire), has been especially valuable in indicating periods at Summit that were likely to have been affected by the long range transport of biomass burning aerosol. Univariate and multivariate patterns of the ion concentrations in the snow and ice pinpointed surface and snowpit samples for the direct analysis of particulate (soot) carbon and carbon isotopes. The research at NIST is focusing on graphitic and polycyclic aromatic carbon, which serve as almost certain indicators of fire, and measurements of carbon isotopes, especially 14C, to distinguish fossil and biomass combustion sources. Complementing the chemical and isotopic record, are direct \u27visual\u27 (satellite imagery) records and less direct backtrajectory records, to indicate geographic source regions and transport paths. In this paper we illustrate the unique way in which the synthesis of the chemical, isotopic, satellite and trajectory data enhances our ability to develop the recent history of the formation and transport of soot deposited in the polar snow and ice

Sediment transport-based metrics of wetland stability

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geophysical Research Letters 42 (2015): 7992–8000, doi:10.1002/2015GL065980.Despite the importance of sediment availability on wetland stability, vulnerability assessments seldom consider spatiotemporal variability of sediment transport. Models predict that the maximum rate of sea level rise a marsh can survive is proportional to suspended sediment concentration (SSC) and accretion. In contrast, we find that SSC and accretion are higher in an unstable marsh than in an adjacent stable marsh, suggesting that these metrics cannot describe wetland vulnerability. Therefore, we propose the flood/ebb SSC differential and organic-inorganic suspended sediment ratio as better vulnerability metrics. The unstable marsh favors sediment export (18 mg L−1 higher on ebb tides), while the stable marsh imports sediment (12 mg L−1 higher on flood tides). The organic-inorganic SSC ratio is 84% higher in the unstable marsh, and stable isotopes indicate a source consistent with marsh-derived material. These simple metrics scale with sediment fluxes, integrate spatiotemporal variability, and indicate sediment sources.U.S. Geological Survey Coastal and Marine Geology Program; Global Change and Land Use Progra

Processes Contributing to Resilience of Coastal Wetlands to Sea-Level Rise

The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sea-level rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by measuring processes controlling wetland elevation. We found that, over 5 years of measurement, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to sea-level rise. We identified fundamental differences in how resilience is maintained across wetland community types, which have important implications for management activities that aim to restore or conserve resilient systems. We showed that the relative importance of surface and subsurface processes in controlling wetland surface elevation change differed between TFFWs and oligohaline marshes. The marshes had significantly higher rates of surface accretion than the TFFWs, and in the marshes, surface accretion was the primary contributor to elevation change. In contrast, elevation change in TFFWs was more heavily influenced by subsurface processes, such as root zone expansion or compaction, which played an important role in determining resilience of TFFWs to rising sea level. When root zone contributions were removed statistically from comparisons between relative sea-level rise and surface elevation change, sites that previously had elevation rate deficits showed a surplus. Therefore, assessments of wetland resilience that do not include subsurface processes will likely misjudge vulnerability to sea-level rise

Processes Contributing to Resilience of Coastal Wetlands to Sea-Level Rise

The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sea-level rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by measuring processes controlling wetland elevation. We found that, over 5 years of measurement, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to sea-level rise. We identified fundamental differences in how resilience is maintained across wetland community types, which have important implications for management activities that aim to restore or conserve resilient systems. We showed that the relative importance of surface and subsurface processes in controlling wetland surface elevation change differed between TFFWs and oligohaline marshes. The marshes had significantly higher rates of surface accretion than the TFFWs, and in the marshes, surface accretion was the primary contributor to elevation change. In contrast, elevation change in TFFWs was more heavily influenced by subsurface processes, such as root zone expansion or compaction, which played an important role in determining resilience of TFFWs to rising sea level. When root zone contributions were removed statistically from comparisons between relative sea-level rise and surface elevation change, sites that previously had elevation rate deficits showed a surplus. Therefore, assessments of wetland resilience that do not include subsurface processes will likely misjudge vulnerability to sea-level rise

Sediment transport-based metrics of wetland stability

Despite the importance of sediment availability on wetland stability, vulnerability assessments seldom consider spatiotemporal variability of sediment transport. Models predict that the maximum rate of sea level rise a marsh can survive is proportional to suspended sediment concentration (SSC) and accretion. In contrast, we find that SSC and accretion are higher in an unstable marsh than in an adjacent stable marsh, suggesting that these metrics cannot describe wetland vulnerability. Therefore, we propose the flood/ebb SSC differential and organic-inorganic suspended sediment ratio as better vulnerability metrics. The unstable marsh favors sediment export (18mgL(-1) higher on ebb tides), while the stable marsh imports sediment (12mgL(-1) higher on flood tides). The organic-inorganic SSC ratio is 84% higher in the unstable marsh, and stable isotopes indicate a source consistent with marsh-derived material. These simple metrics scale with sediment fluxes, integrate spatiotemporal variability, and indicate sediment sources

Fruit crops, 1980: a summary of research

Performance of selected apple cultivars on semi-standard rootstocks in southern Ohio / David C. Ferree, Donald A. Chandler, and John C. Schmid -- Influence of summer pruning and alar on growth, flowering, and fruit set of Jerseymac apple trees / D. C. Ferree and E. J. Stang -- Influence of promalin on Delicious in Ohio / D. C. Ferree, E. J. Stang and R. C. Funt -- The effects of overtree misting for bloom delay on soil water status, net photosynthesis, transpiration, and carbohydrate levels of apple trees / R. M. Crassweller and D. C. Ferree -- Effect of orchard heaters on vertical temperature profiles / R. D. Fox, R. D. Brazee, and D. C. Ferree -- The effect of orchard heaters on air movement and temperature / R. D. Fox, R. D. Brazee, and D. C. Ferree -- Organotins and mite control on apples in Ohio / Franklin R. Hall -- Model of the air sprayer / R. D. Fox, R. D. Brazee, D. L. Reichard and F. R. Hall -- Effects of application equipment variables on spray deposition by orchard air sprayers / D. L. Reichard, F. R. Hall and H. R. Krueger -- Fungi associated with moldy-core of apple and their location within fruit / Michael A. Ellis -- Nutrient content of twelve french and american hybrid grape cultivars grown under a wide range of soil conditions / Garth A. Cahoo

Fruit crops, 1986: a summary of research

Influence of treatments at planting on trellised apple tree performance / David C. Ferree -- Influence of growth regulators on branching of young apple trees / David C. Ferree and John C. Schmid -- Influence of growth regulators on scarf skin of Rome Beauty apples / David C. Ferree and John C. Schmid -- Influence of fungicides on scarf skin on Gallia Beauty / David C. Ferree and Michael A. Ellis -- Little relationship between root pruning and winter injury / James R. Schupp and David C. Ferree -- Performance of two apple cultivars on MS and M9 interstems on Antonovka / D. C. Ferree, R. M. McConnell, and J. C. Schmid -- Air sprayer jet deflection by travel or wind: as predicted by computer / R. D. Fox, R. D. Brazee, and D. L. Reichard -- Measuring atmospheric water vapor / R. D. Brazee and R. D. Fox -- A prototypic pollination unit made from expanded polystyrene / James E. Tew and Dewey M. Caron -- Effects of gibberellic acid (GA3) and daminozide (Alar) on growth and fruiting of Himrod grapes / G. A. Cahoon, M. L. Kaps, and S. P. Pathak -- Development of an action threshold for meadow spittlebug on strawberries / Mark A. Zajac and Franklin R. Hall -- Long-term yield of selected blackberry cultivars and selections in southern Ohio / Craig K. Chandler, Donald A. Chandler, and Greg L. Brenneman -- Electronic information transfer / R. C. Funt. -- A summary of research on synthetic pyrethroids and mites in the apple orchard ecosystem / Franklin R. Hall -- Controlling apple collar rot: effects of fungicides, soil amendments, and depth of planting / M. A. Ellis, D. C. Ferree, and L. V. Madden -- Validation of an electronic unit for predicting apple scab infection periods / M. A. Ellis, L. V. Madden, and L. L. Wilson -- Epidemiology and control of strawberry leather rot / G. G. Grove, M. A. Ellis, and L. V. Madden -- Research on cane diseases of thornless blackberry in Ohio / M. A. Ellis, G. A. Kuter, and L. L. Wilso

Mangrove Peat Collapse Following Mass Tree Mortality: Implications for Forest Recovery from Hurricane Mitch

1 We measured sediment elevation and accretion dynamics in mangrove forests on the islands of Guanaja and Roatan, Honduras, impacted by Hurricane Mitch in 1998 to determine if collapse of underlying peat was occurring as a result of mass tree mortality. Little is known about the balance between production and decomposition of soil organic matter in the maintenance of sediment elevation of mangrove forests with biogenic soils. 2 Sediment elevation change measured with the rod surface elevation table from 18 months to 33 months after the storm differed significantly among low, medium and high wind impact sites. Mangrove forests suffering minimal to partial mortality gained elevation at a rate (5 mm year−1) greater than vertical accretion (2 mm year−1) measured from artificial soil marker horizons, suggesting that root production contributed to sediment elevation. Basin forests that suffered mass tree mortality experienced peat collapse of about 11 mm year−1 as a result of decomposition of dead root material and sediment compaction. Low soil shear strength and lack of root growth accompanied elevation decreases. 3 Model simulations using the Relative Elevation Model indicate that peat collapse in the high impact basin mangrove forest would be 37 mm year−1 for the 2 years immediately after the storm, as root material decomposed. In the absence of renewed root growth, the model predicts that peat collapse will continue for at least 8 more years at a rate (7 mm year−1) similar to that measured (11 mm year−1). 4 Mass tree mortality caused rapid elevation loss. Few trees survived and recovery of the high impact forest will thus depend primarily on seedling recruitment. Because seedling establishment is controlled in large part by sediment elevation in relation to tide height, continued peat collapse could further impair recovery rates

Fruit crops, 1982: a summary of research

Influence of six rootstocks and herbicides on growth, cropping, and fruit quality of Blaxtayman apple trees / David C. Ferree and Robert G. Hill, Jr. -- Tree performance and yield efficiency of several apple cultivars on M9 and M9 interstems / D. C. Ferree -- Chemical induction of lateral shoots on young apple trees / S. C. Myers and D. C. Ferree -- The influence of urea sprays, mulch, and pruning on apple tree decline / G. A. Cahoon and C. W. Donoho, Jr. -- Influence of fireblight and ambrosia beetle on several apple cultivars on M9 and M9 interstems / F. R. Hall, M. A. Ellis, and D. C. Ferree -- A model study of the effect of wind on air sprayer jets / R. D. Fox, D. L. Reichard, and R. D. Brazee -- A comparative study of selected vineyard training and pruning systems for 'Concord' grapevines / G. A. Cahoon -- Effects of selected soil applied herbicides on grapes / Jomo MacDermot and Garth A. Cahoon -- Evaluation of aromatic compounds and virgin females as attractants for rose chafer / Roger N. Williams, Terrence P. McGovern, and Michael Klein -- Botrytis cinerea "gray mold" isolates from strawberry resistant to benlate in Ohio / P. Tanboon-Ek and M. A. Elli

Precision Measurement of the Weak Mixing Angle in Moller Scattering

We report on a precision measurement of the parity-violating asymmetry in fixed target electron-electron (Moller) scattering: A_PV = -131 +/- 14 (stat.) +/- 10 (syst.) parts per billion, leading to the determination of the weak mixing angle \sin^2\theta_W^eff = 0.2397 +/- 0.0010 (stat.) +/- 0.0008 (syst.), evaluated at Q^2 = 0.026 GeV^2. Combining this result with the measurements of \sin^2\theta_W^eff at the Z^0 pole, the running of the weak mixing angle is observed with over 6 sigma significance. The measurement sets constraints on new physics effects at the TeV scale.Comment: 4 pages, 2 postscript figues, submitted to Physical Review Letter