Corona ion induced atmospheric potential gradient perturbations near high voltage power lines

High voltage power lines are known to produce corona ions that can be carried from the line by the wind, progressively attaching to ambient aerosol particles and causing fluctuations in the Earth’s atmospheric potential gradient. A fixed site monitoring station was installed near two power lines, which recorded the potential gradient at 1 s intervals and the ambient weather conditions every 10 min. The station ran continuously from January 2007 to December 2008, accumulating long-term data. Results from 2008 show an increase in potential gradient variability when a wind is blowing across the power lines towards the station, indicating that corona ions may be present in this environment.     

The Tropical Peatland Plantation-Carbon Assessment Tool: estimating CO2 emissions from tropical peat soils under plantations

Land use change on Indonesian peatlands contributes to global anthropogenic greenhouse gas (GHG) emissions. Accessible predictive tools are required to estimate likely soil carbon (C) losses and carbon dioxide (CO₂) emissions from peat soils under this land use change. Research and modelling efforts in tropical peatlands are limited, restricting the availability of data for complex soil model parameterisation and evaluation. The Tropical Peatland Plantation-Carbon Assessment Tool (TROPP-CAT) was developed to provide a user friendly tool to evaluate and predict soil C losses and CO₂ emissions from tropical peat soils. The tool requires simple input values to determine the rate of subsidence, of which the oxidising proportion results in CO₂ emissions. This paper describes the model structure and equations, and presents a number of evaluation and application runs. TROPP-CAT has been applied for both site specific and national level simulations, on existing oil palm and Acacia plantations, as well as on peat swamp forest sites to predict likely emissions from future land use change. Through an uncertainty and sensitivity analysis, literature reviews and comparison with other methods of estimating soil C losses, the paper identifies opportunities for future model development, bridging between different approaches to predicting CO₂ emissions from tropical peatlands under land use change. TROPP-CAT can be accessed online from www.redd-alert.eu in both English and Bahasa Indonesia.     

Modeling potential climate change impacts on the trees of the northeastern United States

We evaluated 134 tree species from the eastern United States for potential response to several scenarios of climate change, and summarized those responses for nine northeastern United States. We modeled and mapped each species individually and show current and potential future distributions for two emission scenarios (A1fi [higher emission] and B1 [lower emission]) and three climate models: the Parallel Climate, the Hadley CM3, and the Geophysical Fluid Dynamics Laboratory model. Climate change could have large impacts on suitable habitat for tree species in this region, especially under a high emissions trajectory. Results indicate that while species with potentially increasing areas of suitable habitat in the Northeastern US substantially outnumber those with decreasing areas of habitat, there are key species that show diminishing habitat area: balsam fir (Abies balsamea), paper birch (Betula papyrifera), red spruce (Picea rubens), bigtooth and quaking aspen (Populus grandidentata and P. tremuloides), and black cherry (Prunus serotina). From these results we identified the top 10 losers and gainers for each US state in the region by scenario and emissions trajectory. By combining individual species importance maps and developing assembly rules for various classes, we created maps of potential forest types for the Northeast showing a general loss of the spruce–fir zone with advancing oak–hickory type. Further data, maps, and analysis can be found at http://www.nrs.fs.fed.us/atlas.     

Analysis of polymeric quaternary ammonium salts as found in cosmetics by metachromatic polyelectrolyte titration

Metachromatic polyelectrolyte titration was investigated as a means of analyzing polymeric quaternary ammonium salts (polyquaterniums) of relatively low charge density used as ingredients in cosmetics. They are of possible toxicological concern, but little is known of their environmental fate and behavior. With o-toluidine blue as the indicator, determination of the concentration of a range of polyquaterniums of commercial importance and cosmetic origin was possible. Using a visual endpoint, normalities as low as 3 × 10^?5 N could be determined, while with a spectrophotometric endpoint, the technique was effective to approximately 3 × 10^?6 N. The concentrations (g L^?1) to which these normalities correspond depend on the charge density of the polymer. Polyquaterniums are frequently used in association with anionic surfactants in cosmetic formulations and the presence of an anionic surfactant even in excess did not affect results although the color change was less stable. Titration in the presence of prepared humic acid was also possible.     

Interlaborafory Comparison of Formaldehyde Emissions from Particleboard Underlayment in Small-Scale Environmental Chambers

Formaldehyde (CH₂O) emissions from particleboard underlayment have been measured in 0.17 and 0.2 m³ chambers at separate laboratories to test the comparability of small scale environmental chamber measurements under different ventilation and product loading conditions. Absolute CH₂O calibration was established through intermethod comparison of different monitoring techniques against a CH₂O generation apparatus. Interlaboratory precision was enhanced via co-calibration of each laboratory’s CH₂O colorimetric analyzer against the same blank and bi-level generation source at the beginning and end of the study. The results show excellent intermethod and interlaboratory agreement in both the CH₂O calibration and particleboard emissions testing. The CH₂O emission rates of the test specimens demonstrate a Fick’s Law dependence on CH₂O vapor concentration. Measured CH₂O concentrations are described by a single-compartment, single emitter model, and are inversely proportional to the ratio [N/L (m/h)] of the air exchange rate [N(h^-1)] and product loading [L(m^-1)]. Comparison tests at varying N and L, but uniform N/L were performed; similar CH2O concentrations were measured for N and L levels selected from an indoor compartment model, and for fivefold larger N and L values, which are more convenient for small-scale chamber testing.     

Extraction of fallout 210Pb from soils and its distribution in soil profiles

Natural fallout ²¹⁰Pb may be extracted from soils with hot, dilute nitric acid without extracting significant quantities of ²¹⁰Pb produced by decay of radon in the soil. This method was used to determine the distribution of fallout ²¹⁰Pb in the profiles of nine New Zealand soils. The measured levels were similar to equilibrium cumulative depositions calculated from deposition records. The results indicate that these soils have quantitatively retained fallout ²¹⁰Pb, with 75–100% of it being concentrated in the top 10 cm of soil. This permanent retention of fallout lead by soils suggests that accumulation of lead in the upper soil layer is likely in areas of aerosol lead pollution.     

Tributary Plunging in an Urban Lake (Onondaga Lake): Drivers,Signatures, and Implications1

Abstract: A combination of long‐term fixed‐frequency and robotic monitoring information for a polluted urban lake, Onondaga Lake, New York, and two of its tributaries is used to resolve the propensity for, and occurrences of, tributary plunging. Cooler temperatures (T) and higher salinity (S) are primarily responsible for the elevated density and plunging of one of these polluted streams for the summer through early fall interval. In‐lake transport of this plunging tributary, which receives inputs from combined sewer overflows (CSOs), is tracked by its high S during dry weather, its high turbidity (T_n) with associated lower S (dilution with rainwater) following runoff events, and by its characteristic ionic composition. These signatures are documented extending from the creek mouth, through a connecting navigation channel, through the inflow zone of the lake, and into metalimnetic depths of pelagic portions of the lake. The entry of this polluted tributary below the depth interval(s) of primary production and contact recreation has important implications for the ongoing major rehabilitation program for this lake. The plunging phenomenon diminishes the benefits previously expected for related features of the lake’s water quality from ongoing management efforts to abate CSO inputs and reduce nonpoint nutrient loading from the tributary. Previously this tributary tended to instead enter the upper layers of the lake during the operation of an adjoining soda ash manufacturing facility (closure in 1986), as a result of high lake S caused by the industry’s ionic waste discharge.     

Population dynamics,delta vulnerability and environmental change: comparison of the Mekong,Ganges–Brahmaputra and Amazon delta regions

Tropical delta regions are at risk of multiple threats including relative sea level rise and human alterations, making them more and more vulnerable to extreme floods, storms, surges, salinity intrusion, and other hazards which could also increase in magnitude and frequency with a changing climate. Given the environmental vulnerability of tropical deltas, understanding the interlinkages between population dynamics and environmental change in these regions is crucial for ensuring efficient policy planning and progress toward social and ecological sustainability. Here, we provide an overview of population trends and dynamics in the Ganges–Brahmaputra, Mekong and Amazon deltas. Using multiple data sources, including census data and Demographic and Health Surveys, a discussion regarding the components of population change is undertaken in the context of environmental factors affecting the demographic landscape of the three delta regions. We find that the demographic trends in all cases are broadly reflective of national trends, although important differences exist within and across the study areas. Moreover, all three delta regions have been experiencing shifts in population structures resulting in aging populations, the latter being most rapid in the Mekong delta. The environmental impacts on the different components of population change are important, and more extensive research is required to effectively quantify the underlying relationships. The paper concludes by discussing selected policy implications in the context of sustainable development of delta regions and beyond.     

The impact of climate change on the soil/moisture regime of Scottish mineral soils

The likely impact of climate change on the moisture regime of Scottish soils and consequently on agriculture and land use has been addressed using a novel Geographic Information Systems (GIS) approach. Current estimates of changes in summer precipitation by the year 2030 are 0% with an associated uncertainty of +/- 11%. This study considers the worst case scenario of a decrease in rainfall by 11% which will lead to some low rainfall areas experiencing an increased drought risk, particularly on lighter soils. Wet areas with heavy soils could benefit from an increase in the accessibility period for machinery. As the major agricultural land in Scotland is located on the relatively dry east coast where localised problems due to drought are not uncommon even under the present climate, the detrimental effects of a decrease in rainfall for the whole of Scotland are therefore likely to outweigh the benefits. Approximately 8% of Scotland has been identified in this study as soil/climate combinations which will be susceptible to drought should summer rainfall decrease by 11% and summer temperature increase by 1.4 degrees C.