A multi-isotope approach for estimating industrial contributions to atmospheric nitrogen deposition in the Athabasca oil sands region in Alberta, Canada

Industrial nitrogen (N) emissions in the Athabasca oil sands region (AOSR), Alberta, Canada, affect nitrate (NO3) and ammonium (NH4) deposition rates in close vicinity of industrial emitters. NO3eN and NH4eN open field and throughfall deposition rates were determined at various sites between 3 km and 113 km distance to the main oil sand operations between May 2008 and May 2009. NO3 and NH4 were analyzed for d15NeNO3, d18OeNO3, D17OeNO3 and d15NeNH4. Marked differences in the d18O and D17O values between industrial emissions and background deposition allowed for the estimation of minimum industrial contributions to atmospheric NO3 deposition. d15NeNH4 values also allowed for estimates of industrial contributions to atmospheric NH4 deposition. Results revealed that particularly sites withinw30 km radius from the main oil sands developments are significantly affected by industrial contributions to atmospheric NO3 and NH4 deposition

Foliage Chemistry of Pinus baksiana in the Athabasca Oil Sands Region, Alberta, Canada

Industrial emissions in the Athabasca Oil Sands Region (AOSR), Alberta, Canada, have caused concerns about the effect of oil sands operations on the surrounding terrestrial environments, including jack pine (Pinus banksiana Lamb.) stands. We collected jack pine needles from 19 sites in the AOSR (13–128 km from main operations) for foliar chemical analyses to investigate the environmental impact on jack pine. Pine needles from three age classes, the current annual growth (CAG, 2011), one year and two year old pine needles, were collected. Samples were analyzed for total carbon (TC), nitrogen (TN), and sulfur (TS), inorganic S (SO4-S), base cations (Ca, Mg, Na), and other elements (B, Cu, Fe, Mn, P, Zn); CAG needles were also analyzed for their nitrogen and carbon isotopic compositions. Only TN, TS, Ca, B, Zn, and Fe contents showed weak but significant increases with proximity to the major oil sands operations. C and N isotopic compositions showed no trend with distance or TC and TN contents. Total S contents in CAG of pine foliage increased significantly with proximity to the main industrial operation while foliar inorganic S to organic S ratios (SO4-S/Sorg) ranged consistently between 0.13 and 0.32, indicating low to moderately high S loading. Hence, this study suggests some evidence of uptake of S emissions in close proximity to anthropogenic sources, although the reported values have not reached a level of environmental concern

Artificial Wetland and Forest Buffer Zone: Hydraulic and Tracer Characterization

As part of a European LIFE ArtWET project, two on-site buffer zones, an artificial wetland and a forest plot, are being evaluated for their capacity to mitigate pesticide pollution. As treatment efficiency is highly dependent on the systems' hydrology, the present work focuses on the watershed and both systems' hydrological functioning. The design strategy involved limited inlet flow rates to 70 L s-1: 99% of watershed outlet flow rates were lower than this limit. Approximately half of the flows of greatest concern passed through the artificial wetland, whereas the forest only received 2% of these flows. A tracer experiment was conducted under a low steady flow rate while little vegetation was present in the artificial wetland. A water dye tracer (sulforhodamine B, SB) and two molecules of contrasting properties, uranine (Ur, photodegrading) and isoproturon (mobile and only slightly sorptive, IPU) were injected. Dilution, sorption, and photodegradation were observed. The forest plot, which presented a high organic matter content, showed more sorption (IPU, SB) but lower photodecay (Ur) than did the artificial wetland. Total IPU losses in the forest buffer were high (79%). In the artificial wetland, 30% IPU losses were found, whereas a 66.5-h mean retention time was determined and good hydraulic efficiency (0.55) was calculated. Few dead zones and short-circuits were found, suggesting good hydrological functioning. Implementing buffer zones in subsurface pipe-drained watersheds actively participates in the reduction of pesticide transfer to natural water bodies

Roosevelt Island Climate Evolution (RICE) ice core isotope record

High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually-dated ice core record from the eastern Ross Sea. Comparison of the Roosevelt Island Climate Evolution (RICE) ice core records with climate reanalysis data for the 1979-2012 calibration period shows that RICE records reliably capture temperature and snow precipitation variability of the region. RICE is compared with data from West Antarctica (West Antarctic Ice Sheet Divide Ice Core) and the western (Talos Dome) and eastern (Siple Dome) Ross Sea. For most of the past 2,700 years, the eastern Ross Sea was warming with perhaps increased snow accumulation and decreased sea ice extent. However, West Antarctica cooled whereas the western Ross Sea showed no significant temperature trend. From the 17th Century onwards, this relationship changes. All three regions now show signs of warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea, but increasing in the western Ross Sea. Analysis of decadal to centennial-scale climate variability superimposed on the longer term trend reveal that periods characterised by opposing temperature trends between the Eastern and Western Ross Sea have occurred since the 3rd Century but are masked by longer-term trends. This pattern here is referred to as the Ross Sea Dipole, caused by a sensitive response of the region to dynamic interactions of the Southern Annual Mode and tropical forcings

The Ross Sea Dipole - temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years

Abstract. High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979–2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE

The Ross Sea Dipole – Temperature, Snow Accumulation and Sea Ice Variability in the Ross Sea Region, Antarctica, over the Past 2,700 Years

Abstract. High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually-dated ice core record from the eastern Ross Sea. Comparison of the Roosevelt Island Climate Evolution (RICE) ice core records with climate reanalysis data for the 1979–2012 calibration period shows that RICE records reliably capture temperature and snow precipitation variability of the region. RICE is compared with data from West Antarctica (West Antarctic Ice Sheet Divide Ice Core) and the western (Talos Dome) and eastern (Siple Dome) Ross Sea. For most of the past 2,700 years, the eastern Ross Sea was warming with perhaps increased snow accumulation and decreased sea ice extent. However, West Antarctica cooled whereas the western Ross Sea showed no significant temperature trend. From the 17th Century onwards, this relationship changes. All three regions now show signs of warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea, but increasing in the western Ross Sea. Analysis of decadal to centennial-scale climate variability superimposed on the longer term trend reveal that periods characterised by opposing temperature trends between the Eastern and Western Ross Sea have occurred since the 3rd Century but are masked by longer-term trends. This pattern here is referred to as the Ross Sea Dipole, caused by a sensitive response of the region to dynamic interactions of the Southern Annual Mode and tropical forcings