Meteorological Factors of Ozone Predictability at Houston,Texas

ABSTRACT

Several ozone modeling approaches were investigated to determine if uncertainties in the meteorological data would be sufficiently large to limit the application of physically realistic ozone (O₃) forecast models. Three diagnostic schemes were evaluated for the period of May through September 1997 for Houston, TX. Correlations between measured daily maximum and model calculated O₃ air concentrations were found to be 0.70 using a linear regression model, 0.65 using a non-advective box model, and 0.49 using a three-dimensional (3-D) transport and dispersion model. Although the regression model had the highest correlation, it showed substantial underestimates of the highest concentrations. The box model results were the most similar to the regression model and did not show as much underestimation. The more complex 3-D modeling approach yielded the worst results, likely resulting from O₃ maxima that were driven by local factors rather than by the transport of pollutants from outside of the Houston domain. The highest O₃ concentrations at Houston were associated with light winds and meandering trajectories. A comparison of the gridded meteorological data used by the 3-D model to the observations showed that the wind direction and speed values at Houston differed most on those days on which the O₃ underestima-tions were the greatest. These periods also tended to correspond with poor precipitation and temperature estimates. It is concluded that better results are not just obtained through additional modeling complexity, but there needs to be a comparable increase in the accuracy of the meteorological data.     

Invasion of <Emphasis Type="Italic">Mimosa pigra</Emphasis> on the cultivated Mekong River floodplains near Kratie,Cambodia: farmers’ coping strategies,perceptions, and outlooks

Mimosa pigra, an alien woody weed, invaded the Mekong River Basin since ~1970 and now covers vast floodplain areas in virtual monocultures. The prickly plants produce abundant seeds which are dispersed annually by the floods. Mimosa thus represents a burden to farming communities in Cambodia where agricultural capacities are weak. To obtain information on infestations as well as farmers’ management practices and perceptions, 81 farmers were interviewed on their fields (using questionnaires) in affected areas near Kratie municipality. Data on infestations were collected at landscape and field levels. Furthermore, villagers’ groups and key informants were interviewed (open questions). Infestations covered ~30 % of the land near fields. On average, farmers spent 11 days per hectare annually clearing mimosa. The weed represented a major cost, but other issues (animal pests, water shortages, lack of resources) were equally important; these may be connected with mimosa invasion. Farmers mostly expressed support for ideas to combat surrounding infestations, but support depended on experiences and assets at stake. Most were unconvinced that mimosa could be eliminated from the study site. Conceivable benefits of mimosa were regarded as insignificant. Given the currently few realistic options for significantly improving management, further research is suggested within adaptive management frameworks.     

NHDPlusHR: A National Geospatial Framework for Surface‐Water Information

The U.S. Geological Survey is developing a new geospatial hydrographic framework for the United States, called the National Hydrography Dataset Plus High Resolution (NHDPlusHR), that integrates a diversity of the best‐available information, robustly supports ongoing dataset improvements, enables hydrographic generalization to derive alternate representations of the network while maintaining feature identity, and supports modern scientific computing and Internet accessibility needs. This framework is based on the High Resolution National Hydrography Dataset, the Watershed Boundaries Dataset, and elevation from the 3‐D Elevation Program, and will provide an authoritative, high precision, and attribute‐rich geospatial framework for surface‐water information for the United States. Using this common geospatial framework will provide a consistent basis for indexing water information in the United States, eliminate redundancy, and harmonize access to, and exchange of water information.     

Global change impacts on the Upper Danube Catchment (Central Europe): a study of participatory modeling

Participatory modeling (PM) has become an essential concept in environmental impact assessment and planning in the field of water resources. In this paper, we focus on the use of PM to support the development of the integrated regional modeling system DANUBIA as a scientific concept to analyze the previously unknown impacts of global change, i.e., the combined effects of climate, demographic, economic, social and ecological change, on the Upper Danube Catchment (Germany). We use this case study to examine the specific conditions for PM in the field of complex integrated models on a regional scale. We describe the stepwise PM process and discuss the respective results, focusing on (1) the stakeholder dialogue’s contribution in supporting the development of new, complex modeling systems, particularly on a regional scale, (2) conditions of stakeholder involvement in issues related to the distant future, such as climate change impacts on regional water availability, and (3) limitations of PM and scientists’ motivation to carry out participatory research at all. We conclude that the PM process was not entirely successful in improving the scientific quality and practical applicability of the developed models because the process goals were manifold and overambitious, and the definition of the problem of “global change impacts on a regional scale” was too weak and uncertain to allow for a clear common objective of modelers and stakeholders. We claim that there is a lack of incentives for scientists, particularly natural scientists, to commit to PM activities.     

Dioxin/POPs legacy of pesticide production in Hamburg: Part 1—securing of the production area

α-Hexachlorocyclohexane (HCH), β-HCH, and γ-HCH (lindane) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention. Therefore, the chemicals need to be globally addressed, including the disposal of historic wastes. At most sites, the approximately 85 % of HCH waste isomers were dumped. At a former lindane factory in Hamburg and some other factories the HCH, waste was recycled producing residues with high polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDF) levels. The soil and ground water under the former pesticide factory was/is highly contaminated with HCH (260 tons), chlorobenzenes (550 tons), and PCDD/PCDF (6 kg toxic equivalents (TEQ)). This contamination did not result from disposal operations but from spillages and leakages during the 30 years of the factory's production history. A containment wall has been constructed around the production area to prevent the dispersal of the pollutants. The ground water is managed by a pump and treat system. Over the last 15 years, approximately 10–30 tons of this pollution reservoir has been pumped and incinerated. For the contaminated production buildings, specific assessment and demolition technologies have been applied. In addition to their HCH waste isomer deposition, former lindane/HCH productions need to be assessed for possible recycling practice of HCH and related PCDD/PCDF contamination of the production area and buildings. Since such recycling activities have taken place at several factories in different countries, the experience of assessment and management of the described production area and contaminated buildings could be valuable. Such assessment could be addressed within the frame of the Stockholm Convention.     

PFOS and PFC releases and associated pollution from a PFC production plant in Minnesota (USA)

Perfluorooctane sulfonate (PFOS) and PFOS-related substances have been listed as persistent organic pollutants in the Stockholm Convention. From August 2012, Parties to the Convention needed to address the use, storage, and disposal of PFOS—including production sites and sites where PFOS wastes have been deposited—in their national implementation plans. The paper describes the pollution in Minnesota (USA) caused by the 3M Company at one of the largest per/polyfluorinated chemical (PFC) production facilities. From early 1950s until the end of 2002, when 3M terminated PFOS and perfluorooctanoic acid (PFOA) production, PFOS, PFOA, and other PFC production wastes were disposed around the plant and in local disposal sites. Discharges from the site and releases from deposits caused widespread contamination of ground and surface waters including local drinking water wells. Fish in the river downstream were contaminated with PFOS to levels that led to fish consumption advisories. Human exposures resulted from ingesting contaminated drinking water, requiring installation of water treatment facilities and alternate water supplies. The critical evaluation of the assessments done revealed a range of gaps in particular of human exposure where relevant exposure pathways including the entire exposure via food have not been taken into consideration. Currently, the exposure assessment of vulnerable groups such as children or Hmong minorities is inadequate and needs to be improved/validated by epidemiological studies. The assessment methodology described for this site may serve—with highlighted improvements—as a model for assessment of other PFOS/PFC production sites in the Stockholm Convention implementation.     

Climate Change,Land Use Conflicts,Predation and Ecological Degradation as Challenges for Reindeer Husbandry in Northern Europe: What do We Really Know After Half a Century of Research?

Reindeer grazing has been entitled as ecological keystone in arctic-alpine landscapes. In addition, reindeer husbandry is tightly connected to the identity of the indigenous Sámi people in northern Europe. Nowadays, reindeer husbandry is challenged in several ways, of which pasture degradation, climate change, conflicting land uses and predation are the most important. Research on reindeer-related topics has been conducted for more than half a century and this review illuminates whether or not research is capable to match these challenges. Despite its high quality, traditional reindeer-related research is functionally isolated within the various disciplines. The meshwork of ecology, socio-economy, culture and politics, however, in which reindeer husbandry is embedded by various interactions, will remain unclear and difficult to manage, if actors and relationships are kept separate. We propose some targets for new integrative research approaches that incorporate traditional knowledge and focus on the entire human-ecological system 'reindeer husbandry' to develop solutions for its challenges.     

Ecosystem responses to reduced and oxidised nitrogen inputs in European terrestrial habitats

While it is well established that ecosystems display strong responses to elevated nitrogen deposition, the importance of the ratio between the dominant forms of deposited nitrogen (NH_x and NO_y) in determining ecosystem response is poorly understood. As large changes in the ratio of oxidised and reduced nitrogen inputs are occurring, this oversight requires attention. One reason for this knowledge gap is that plants experience a different NH_x:NO_y ratio in soil to that seen in atmospheric deposits because atmospheric inputs are modified by soil transformations, mediated by soil pH. Consequently species of neutral and alkaline habitats are less likely to encounter high NH₄⁺ concentrations than species from acid soils. We suggest that the response of vascular plant species to changing ratios of NH_x:NO_y deposits will be driven primarily by a combination of soil pH and nitrification rates. Testing this hypothesis requires a combination of experimental and survey work in a range of systems.     

Modeling biogeochemical processes of phosphorus for global food supply

Harvests of crops, their trade and consumption, soil erosion, fertilization and recycling of organic waste generate fluxes of phosphorus in and out of the soil that continuously change the worldwide spatial distribution of total phosphorus in arable soils. Furthermore, due to variability in the properties of the virgin soils and the different histories of agricultural practices, on a planetary scale, the distribution of total soil phosphorus is very heterogeneous. There are two key relationships that determine how this distribution and its change over time affect crop yields. One is the relationship between total soil phosphorus and bioavailable soil phosphorus and the second is the relationship between bioavailable soil phosphorus and yields. Both of these depend on environmental variables such as soil properties and climate. We propose a model in which these relationships are described probabilistically and integrated with the dynamic feedbacks of P cycling in the human ecosystem. The model we propose is a first step towards evaluating the large-scale effects of different nutrient management scenarios. One application of particular interest is to evaluate the vulnerability of different regions to an increased scarcity in P mineral fertilizers. Another is to evaluate different regions’ deficiency in total soil phosphorus compared with the level at which they could sustain their maximum potential yield without external mineral inputs of phosphorus but solely by recycling organic matter to close the nutrient cycle.     

Monitoring nitrogen accumulation in mosses in central European forests

In order to assess whether nitrogen (N) loads in mosses reflect different land uses, 143 sites in North Rhine-Westphalia, the Weser-Ems Region and the Euro Region Nissa were sampled between 2000 and 2005. The data were analysed statistically with available surface information on land use and forest conditions. N bioaccumulation in mosses in the Weser-Ems Region with high densities of agricultural land use and livestock exceeded the concentrations in the more industrialised Euro Region Nissa. In all three study areas agricultural and livestock spatial densities were found to be positively correlated with N bioaccumulation in mosses. In North Rhine-Westphalia, the N concentrations in mosses was also moderately correlated with N concentrations in leaves and needles of forest trees. The moss method proved useful to assess the spatial patterns of N bioaccumulation due to land use.