Latitudinal Distribution of O2on Ganymede: Observations with the Hubble Space Telescope

To help constrain the spatial variation of oxygen on Jupiter's satellite Ganymede, and hence have more clues to its mode of production and stability, we have obtained spectral data from the Faint Object Spectrograph (FOS) for a single pole-to-pole latitudinal strip, along with several Wide Field Planetary Camera 2 (WFPC2) images in three narrow band visible filters. All observations were made of the trailing hemisphere. In the FOS data we observe both visible absorptions at 0.577 and 0.627 μm, associated with dense-phase oxygen (compressed gases, liquids, or solids). Filter options limited the WFPC2 observations to wavelengths near the weaker oxygen absorption at 0.627 μm. These observations suggest that the dense-phase or dimer oxygen form is predominantly found in equatorial and mid-latitudes. The spectroscopic absorption feature appears in both bright and dark terrains but may be somewhat weaker in dark regions, which is consistent with the smaller mean photon path length in the surface in darker areas. Therefore, the abundance of oxygen appears more dependent on latitude and longitude constraints than surface albedo. At the highest latitudes, where the ratio spectra have a strong upturn toward the blue, the oxygen bands do not appear. This relation suggests that dimer oxygen and ozone (as seen by Galileo) have opposite trends with latitude. Possible causes include competition or variation in the preferred stable form, which depends on temperature, solar ultraviolet flux, and/or surface age; enhancement of O₃at the poles due to plasma interactions; or viewing geometry effects that reduce the oxygen features at the poles when observed from Earth. The predominantly equatorial feature supports the production of O₂through plasma bombardment and favors defect trapping over physical adsorption of the dimer molecules in the surface. We briefly consider the implications of Ganymede's magnetosphere for our understanding of O₂and O₃distribution on Ganymede.     

“Doing Geography”: Evaluating an Independent Geographic Inquiry Assessment Task in an Initial Teacher Education Program

The assessment task of the final course in a bachelor of secondary education program is examined for opportunities for preservice geography teachers to achieve the course aims of integrating, consolidating, applying, and reflecting on the knowledge and skills they have learned during their initial teacher education program. The results show that the preservice teachers did better in some areas (integrating, consolidating, and reflecting) than in others (applying). This has implications for curriculum renewal in geography methods courses—specifically to provide more opportunities for preservice teachers to practice applying the knowledge and skills they have gained during the program, essential for their future roles as senior geography teachers.     

“We Don’t Take the Pledge”: Environmentality and environmental skepticism at the epicenter of US wind energy development

This study analyzes pro-wind, “anti-environmental” discourses prevalent among key stakeholders in Nolan County, Texas, the epicenter of US wind power. We draw upon interviews conducted within a Q-method study to examine environmental views held by key actors in wind-farm development. We frame our analysis within the theoretical field that engages the formation of environmental subjects, defined as the process through which individuals and communities align their environmental practices with state ends. We argue that this is a process that can be incomplete or in tension with other subject positions, which together may lead to unexpected environmental views. We introduce “environmental skepticism,” defined as a rejection of ecological science steeped in deep anthropocentrism and possessive individualism, as a dominant counter-narrative informing certain environmental subjectivities. The remainder of the paper describes Texas wind stakeholders’ views or subject positions on energy and the environment and reveals how environmental skepticism is not overturned even as renewable energy supports the local economy. We analyze wind stakeholders’ environmental subjectivity in terms of emergent subject positions as “reflexive environmental skepticism,” a view that accepts the economic products, processes, and policy innovations advocated by ecological modernization without accepting the core claim that innovations are required to adapt to environmental change.     

Travelling technocrats, embodied knowledges: Globalising privatisation in telecoms and water

The decade from the mid-1980s to the mid-1990s was a key moment in the unfolding of the global privatisation agenda. During this decade privatisation shifted from a nation-state project to become part of the structural adjustment measures associated with economic globalisation. These measures were not only promoted by international institutions such as the World Bank and IMF, but by a range of other organisations and actors who have received little attention. In particular, virtually no attention has been paid to the mid-level technocrats who enacted privatisation strategies and techniques. This paper focuses on these actors through the cases of New Zealand telecommunications engineers and British water engineers. In discussing the significance of these actors we argue for the unpacking of the messy histories, geographies and sociologies of privatisation using both publicly available documents and ethnographic methods. This will allow us to understand why certain courses of action were pursued in particular times and places, why other actions dropped out, and will reveal more about the national imaginaries and embodied knowledges underpinning the globalisation of privatisation.     

Conservation in a complex management environment: The by-catch of sea turtles in North Carolina’s commercial fisheries

Despite a powerful, federal legislative framework established to protect threatened and endangered species in the United States, conservation actions can be hindered by the complexity of the full management structure. This is particularly true when state and federal agencies share the responsibility to conserve endangered species. To illustrate this point, this paper describes the management of sea turtle by-catch in commercial fisheries within the state waters of North Carolina. It reviews past and present by-catches, summarizes state and federal efforts intended to reduce sea turtle by-catch, and discusses the challenges posed by the involvement of multiple agencies with conflicting objectives. It concludes by recommending fundamental changes to this management framework and, in particular, proposes the establishment of a multilayered stakeholder group that would work to reduce sea turtle by-catch while supporting vibrant commercial fisheries in the state.     

An evaluation of the application of CHEMTAX to Antarctic coastal pigment data

Presented is an evaluation of the application of CHEMTAX (CHEMical TAXonomy) to Antarctic coastal pigments collected along the western Antarctic Peninsula (wAP). Overall analytical error is <20% for all pigments involved in the analysis. CHEMTAX was stable within a range of input pigment ratios; data were analyzed in three bins based on light depths, with each year's data run independently. Results were validated by comparison to those from CHEMTAX methods that included randomized error, feedback loops and additional diagnostic pigments. Blooms during mid-summer (chlorophyll a concentrations >5 ??g L⁻¹) were dominated primarily by either diatoms or cryptomonads. Mixed flagellates can also be abundant and Pheaocystis spp. and prasinophytes are frequently present in low concentrations. Comparison with microscopy shows CHEMTAX to give superior results in identifying Pheaocystis spp. with favorable results for other groups. This analysis shows CHEMTAX to be a reliable and stable tool for providing estimations of the main phytoplankton taxa in wAP waters based on long-term data collected during a 12-year time series.     

Sewer Gas: An Indoor Air Source of PCE to Consider During Vapor Intrusion Investigations

The United States Environmental Protection Agency (USEPA) is finalizing its vapor intrusion guidelines. One of the important issues related to vapor intrusion is background concentrations of volatile organic compounds (VOCs) in indoor air, typically attributed to consumer products and building materials. Background concentrations can exist even in the absence of vapor intrusion and are an important consideration when conducting site assessments. In addition, the development of accurate conceptual models that depict pathways for vapor entry into buildings is important during vapor intrusion site assessments. Sewer gas, either as a contributor to background concentrations or as part of the site conceptual model, is not routinely evaluated during vapor intrusion site assessments. The research described herein identifies an instance where vapors emanating directly from a sanitary sewer pipe within a residence were determined to be a source of tetrachloroethylene (PCE) detected in indoor air. Concentrations of PCE in the bathroom range from 2.1 to 190 µg/m³ and exceed typical indoor air concentrations by orders of magnitude resulting in human health risk classified as an “Imminent Hazard” condition. The results suggest that infiltration of sewer gas resulted in PCE concentrations in indoor air that were nearly two orders of magnitude higher as compared to when infiltration of sewer gas was not known to be occurring. This previously understudied pathway whereby sewers serve as sources of PCE (and potentially other VOC) vapors is highlighted. Implications for vapor intrusion investigations are also discussed.     

Imagining the Dirty Green City

ABSTRACT

The green city is being elevated to the status of a self-evident good in the theory and practice of urban sustainability. A large literature documents the linked environmental, economic and well-being benefits associated with vegetating urban systems to maximise the ecosystem function. Contemporary urban greening seeks to challenge attempts to expel nature from the city in a quest for order and control. However, by imagining nature as a new mode of urban purification, much effort in the name of the green city inverts and reproduces dualistic understandings of natural and built space. In response, we disrupt the normative dialectics of purity and dirt that sustain this dualism to expose the untidy but fertile ground of the green city. We draw together Ash Amin’s four registers of the Good City – relatedness, rights, repair and re-enchantment – with the artworks of the Australian visual ecologist Aviva Reed. Our work seeks to enrich the practice of more-than-human urbanism through ‘dirt thinking’ by imagining the transformative possibilities in, of and for the dirty green city.     

Application of 1D paleo‐fluvial process modelling at a basin scale to augment sparse borehole data: example of a Permian formation in the Galilee Basin,Australia

The heterogeneous hydraulic conductivity (K) in water‐bearing formations controls subsurface flow and solute transport processes. Geostatistical techniques are often employed to characterize the K distribution in space based on the correlation between K measurements. However, at the basin scale, there are often insufficient measurements for inferring the spatial correlation. This is a widespread problem that we address in this study using the example of the Betts Creek Beds (BCB) in the Galilee Basin, Australia. To address the lack of data, we use a 1D stochastic fluvial process‐based model (SFPM) to quantify the total sediment thickness, Z( x ), and the sandstone proportion over the total thickness, P_s( x ), in the BCB. The semivariograms of Z( x ) and P_s( x ) are then extracted and used in sequential Gaussian simulation to construct the 2D spatial distribution of Z( x ) and P_s( x ). P_s( x ) can be converted to a K distribution based on classical averaging methods. The results demonstrate that the combination of SFPM and geostatistical simulation allows for the evaluation of upscaled K distribution with a limited number of K measurements. Copyright © 2015 John Wiley & Sons, Ltd.     

New Fellow of the Royal Society of Chemistry (FRSC)

News and Notes

New Fellow of the Royal Society of Chemistry (FRSC)