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Sample records for canadian arctic archipelago

  1. Arctic environments and global change: Evidence in deep permafrost temperatures, Canadian arctic archipelago

    International Nuclear Information System (INIS)

    In considering the role of the polar regions in future global change, one may look toward these regions for evidence of past environmental change. Deep ground temperatures provide one window on past surface temperatures, which may be interpreted in terms not only of past climate but also of past environmental conditions. Across the Canadian Arctic Archipelago, there is no consistent curvature in deep ground temperature profiles that can be modeled in terms of warming of the past century. This contrasts with the result reported by Lachenbruch et al. [1986] for the Prudhoe Bay area of Alaska and may be a consequence of the much larger region and wider well spacing considered in the Canadian case. Any curvature present varies from well to well and may be interpreted in terms of surface temperature changes of the order of 1-3 K on the scale of decades to centuries. However, there is some evidence that these surface temperature histories may arise from long-term changes in paleoenvironmental factors as well as climate. For instance, the paleoclimate derived from oxygen isotope data at the Agassiz Ice Cap has been compared with the geothermal signature at a well some 180 km to the west. For the Little Ice Age (LIA), the Agassiz paleoclimate explains only half the measured variation in ground temperatures at the geothermal site; the remaining variation may be due to other environmental effects, such as an increase in snow cover following the LIA. This is consistent with extrapolated surface temperatures 7 K higher than other Arctic sites and the unusually deep snow cover observed today

  2. Projected polar bear sea ice habitat in the Canadian Arctic Archipelago.

    Directory of Open Access Journals (Sweden)

    Stephen G Hamilton

    Full Text Available Sea ice across the Arctic is declining and altering physical characteristics of marine ecosystems. Polar bears (Ursus maritimus have been identified as vulnerable to changes in sea ice conditions. We use sea ice projections for the Canadian Arctic Archipelago from 2006 - 2100 to gain insight into the conservation challenges for polar bears with respect to habitat loss using metrics developed from polar bear energetics modeling.Shifts away from multiyear ice to annual ice cover throughout the region, as well as lengthening ice-free periods, may become critical for polar bears before the end of the 21st century with projected warming. Each polar bear population in the Archipelago may undergo 2-5 months of ice-free conditions, where no such conditions exist presently. We identify spatially and temporally explicit ice-free periods that extend beyond what polar bears require for nutritional and reproductive demands.Under business-as-usual climate projections, polar bears may face starvation and reproductive failure across the entire Archipelago by the year 2100.

  3. Exchanges of volume, heat and freshwater through the Canadian Arctic Archipelago: a numerical study.

    Science.gov (United States)

    Grivault, Nathan; Hu, Xianmin; Myers, Paul G.

    2016-04-01

    The Canadian Arctic Archipelago (CAA) is a tangle of shallow basins interlinked by narrow straits. It is the main pathway of liquid freshwater from the Arctic Ocean to North Atlantic. It also receives runoff from the Mackenzie River and the glaciers of the different islands that composes the archipelago. This study is based on a set of numerical experiments using a regional configuration of the coupled ocean/sea-ice general circulation model NEMO. We consider a long-term hindcast (1958-2014) as well as the more recent period (2002-2014) using high resolution inter-annual forcing from Environment Canada. We used an improved mapping of runoff to ensure correct amounts of freshwater are added to the system. We evaluate the flow pathways through the CAA, as well as the transport of volume, heat and freshwater. Results are evaluated against observational sections. We also look at the variability and the dynamics driving it. Passive tracers are used to complement the analysis.

  4. Sea ice melt onset dynamics in the northern Canadian Arctic Archipelago from RADARSAT

    Science.gov (United States)

    Mahmud, M. S.; Howell, S.; Geldsetzer, T.; Yackel, J.

    2015-12-01

    Sea ice melt onset, the appearance of liquid water in its snow cover, decreases surface albedo which increases shortwave absorption and thereby accelerates snow and sea ice melting. Earlier melt onset leads to the earlier formation of open water which enhances the ice-albedo feedback. Sea ice melt onset timing and duration vary considerably, both spatially and temporally, owing to variability in atmospheric forcing; this in turn influences the September sea ice extent. Sea ice melt onset variability has been investigated using coarse resolution passive microwave observation in Canadian Arctic Archipelago (CAA); however, this does not provide sufficient information about sea ice melt dynamics. We developed a new melt onset algorithm using high resolution synthetic aperture radar (SAR) images from RADARSAT to better understand sea ice melt onset dynamics in northern Canadian Arctic Archipelago (fig 1) from 1997 to 2014. The algorithm is based on the temporal evolution of the SAR backscatter coefficient (σo), using separate thresholds for seasonal first-year ice and multi-year ice. Results indicated that the mean annual average melt onset date in the northern CAA was on year day 164 (mid-June) with a standard deviation of 4 days over the 18 year period. No significant trend for melt onset date was found over the 18 year period (fig: 2) but extreme early melt onset was detected in 1998 and 2012 associated with anomalous atmospheric forcing. Spatially, sea ice onset over the entire northern CAA varied from a 10-day minimum in 2007, to a 35-day maximum in 2011 and exhibited negative correlation (r=0.70) with the rate of increase in surface air temperature (fig 3) derived from Extended AVHRR Polar Pathfinder (APP-x) dataset. An earlier (later) melt onset also results in light (heavier) September sea ice area in the northern CAA (fig 4).

  5. Recent changes in the multi-year ice area budget of the Canadian Arctic Archipelago

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    Howell, Stephen; Pizzolato, Larissa; Derksen, Chris; Brady, Michael

    2014-05-01

    The Canadian Arctic Archipelago (CAA) is intricate collection of islands and channels located on the North American continental shelf. The deep-water route of the North West Passage crosses through the CAA near 75°N connecting the Atlantic and Pacific Oceans. The major challenge to safe navigation of the North West Passage is the presence of multi-year sea ice (MYI). In recent years, MYI conditions within the CAA during September have begun to decrease considerably with 2011 and 2012 being the lightest MYI years on record since 1968. Recent light MYI years within the CAA are associated with recent openings of the North West Passage (i.e. 2007, 2008, 2010, 2011 and 2012). MYI within the CAA is either imported from the Arctic Ocean or grown in situ and therefore in order to understand the processes contributing to these recent reductions in September MYI within the CAA we derived the first estimates of the MYI area budget of the CAA using RADARSAT-1 and RADARSAT-2 imagery from 1997-2012. Overall, there has been a reduced amount of Arctic Ocean MYI inflow into the CAA during the summer months since 2007. The latter process can be attributed to more frequent high sea level pressure anomalies over the Beaufort Sea and Canadian Basin. The amount of MYI grown in situ within the CAA has also reduced because of longer melt seasons reducing the survivability of seasonal ice over. MYI outflow to Baffin Bay from the CAA has been relatively consistent over the period. Interestingly, the recent reduced amount of MYI within the CAA, particularly noticeable since 2007, was found to be quantitatively linked with a step change increase in observed Arctic marine shipping activity following the dramatic summer sea ice reductions that began in 2007.

  6. Summertime sources of dimethyl sulfide in the Canadian Arctic Archipelago and Baffin Bay

    Science.gov (United States)

    Mungall, E. L.; Croft, B.; Lizotte, M.; Thomas, J. L.; Murphy, J. G.; Levasseur, M.; Martin, R. V.; Wentzell, J. J. B.; Liggio, J.; Abbatt, J. P. D.

    2015-12-01

    Dimethyl sulfide (DMS) plays a major role in the global sulfur cycle. In addition, its atmospheric oxidation products contribute to the formation and growth of atmospheric aerosol particles, thereby influencing cloud condensation nuclei (CCN) populations and thus cloud formation. The pristine summertime Arctic atmosphere is a CCN-limited regime, and is thus very susceptible to the influence of DMS. However, atmospheric DMS mixing ratios have only rarely been measured in the summertime Arctic. During July-August 2014, we conducted the first high time resolution (10 Hz) DMS mixing ratio measurements for the Eastern Canadian Archipelago and Baffin Bay as one component of the Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments (NETCARE). DMS mixing ratios ranged from below the detection limit of 4 to 1155 pptv (median 186 pptv). A set of transfer velocity parameterizations from the literature coupled with our atmospheric and coincident seawater DMS measurements yielded air-sea DMS flux estimates ranging from 0.02-12 μmol m-2 d-1, the first published for this region in summer. Airmass trajectory analysis using FLEXPART-WRF and chemical transport modeling using GEOS-Chem indicated that local sources (Lancaster Sound and Baffin Bay) were the dominant contributors to the DMS measured along the 21 day ship track, with episodic transport from the Hudson Bay System. After adjusting GEOS-Chem oceanic DMS values in the region to match measurements, GEOS-Chem reproduced the major features of the measured time series, but remained biased low overall (median 67 pptv). We investigated non-marine sources that might contribute to this bias, such as DMS emissions from lakes, biomass burning, melt ponds and coastal tundra. While the local marine sources of DMS dominated overall, our results suggest that non-local and possibly non-marine sources episodically contributed strongly to the observed summertime Arctic DMS mixing ratios.

  7. Landfast ice thickness in the Canadian Arctic Archipelago from observations and models

    Science.gov (United States)

    Howell, Stephen E. L.; Laliberté, Frédéric; Kwok, Ron; Derksen, Chris; King, Joshua

    2016-07-01

    Observed and modelled landfast ice thickness variability and trends spanning more than 5 decades within the Canadian Arctic Archipelago (CAA) are summarized. The observed sites (Cambridge Bay, Resolute, Eureka and Alert) represent some of the Arctic's longest records of landfast ice thickness. Observed end-of-winter (maximum) trends of landfast ice thickness (1957-2014) were statistically significant at Cambridge Bay (-4.31 ± 1.4 cm decade-1), Eureka (-4.65 ± 1.7 cm decade-1) and Alert (-4.44 ± 1.6 cm -1) but not at Resolute. Over the 50+-year record, the ice thinned by ˜ 0.24-0.26 m at Cambridge Bay, Eureka and Alert with essentially negligible change at Resolute. Although statistically significant warming in spring and fall was present at all sites, only low correlations between temperature and maximum ice thickness were present; snow depth was found to be more strongly associated with the negative ice thickness trends. Comparison with multi-model simulations from Coupled Model Intercomparison project phase 5 (CMIP5), Ocean Reanalysis Intercomparison (ORA-IP) and Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) show that although a subset of current generation models have a "reasonable" climatological representation of landfast ice thickness and distribution within the CAA, trends are unrealistic and far exceed observations by up to 2 orders of magnitude. ORA-IP models were found to have positive correlations between temperature and ice thickness over the CAA, a feature that is inconsistent with both observations and coupled models from CMIP5.

  8. Topoclimatic modeling of summer surface air temperature in the Canadian Arctic Archipelago

    Science.gov (United States)

    Atkinson, David E.

    2000-06-01

    In the Canadian High Arctic general patterns of temperature are poorly resolved at the meso-scale. This project addressed this issue in three stages. In the first stage a data set of non-standard weather observations was assembled and quality controlled The data set possessed approximately 58000 observations, including dry-bulb temperature, wind, visibility and cloud cover, from the spring and summer seasons of the years 1974-1993. Up to 10% of the data were unusable due to erroneous station information. The second part of the project consisted of a principal components analysis (PCA) of daily temperature data in the Canadian Arctic Archipelago (CAA). The PCA (1)demonstrated how the timing and extent of synoptic events could be tracked, (2)identified the major regional controls of temperature in the CAA, and (3)showed that the non-standard data exhibited general coherency with regional patterns yet were able to reveal zones of coherency at the meso-scale in temperature patterns. In the third stage of the project a model to estimate surface air temperature at the meso-scale was constructed, It was based on a 1 km resolution digital elevation model of the CAA. The effects on temperature due to site elevation and coastal proximity were selected for parameterization. The change in temperature with elevation was implemented in the model using derived environmental lapse rates. Advection effects were handled using resultant winds combined with air temperature above the ocean. Lapse rates and resultant wind estimates were obtained from upper air ascents. Model results for 14-day runs were compared to observed data. Residuals (n = 385) possessed a mean absolute error of 1.5°C. The model was sensitive to steep surface inversions and to low- level warming. Sensitivity analyses were performed on the model to determine response to alterations in lapse rate calculation, sea surface temperature, and wind field generation. The model was most sensitive to lapse rate calculation

  9. Late Pleistocene ice export events into the Arctic Ocean from the M'Clure Strait Ice Stream, Canadian Arctic Archipelago

    Science.gov (United States)

    Stokes, Chris R.; Clark, Chris D.; Darby, Dennis A.; Hodgson, Douglas A.

    2005-12-01

    Rapidly-flowing sectors of an ice sheet (ice streams) can play an important role in abrupt climate change through the delivery of icebergs and meltwater and the subsequent disruption of ocean thermohaline circulation (e.g., the North Atlantic's Heinrich events). Recently, several cores have been raised from the Arctic Ocean which document the existence of massive ice export events during the Late Pleistocene and whose provenance has been linked to source regions in the Canadian Arctic Archipelago. In this paper, satellite imagery is used to map glacial geomorphology in the vicinity of Victoria Island, Banks Island and Prince of Wales Island (Canadian Arctic) in order to reconstruct ice flow patterns in the highly complex glacial landscape. A total of 88 discrete flow-sets are mapped and of these, 13 exhibit the characteristic geomorphology of palaeo-ice streams (i.e., parallel patterns of large, highly elongated mega-scale glacial lineations forming a convergent flow pattern with abrupt lateral margins). Previous studies by other workers and cross-cutting relationships indicate that the majority of these ice streams are relatively young and operated during or immediately prior to deglaciation. Our new mapping, however, documents a large (> 700 km long; 110 km wide) and relatively old ice stream imprint centred in M'Clintock Channel and converging into Viscount Melville Sound. A trough mouth fan located on the continental shelf suggests that it extended along M'Clure Strait and was grounded at the shelf edge. The location of the M'Clure Strait Ice Stream exactly matches the source area of 4 (possibly 5) major ice export events recorded in core PS1230 raised from Fram Strait, the major ice exit for the Arctic Ocean. These ice export events occur at ˜12.9, ˜15.6, ˜22 and 29.8 ka ( 14C yr BP) and we argue that they record vigorous episodes of activity of the M'Clure Strait Ice Stream. The timing of these events is remarkably similar to the North Atlantic's Heinrich

  10. Recent extreme light sea ice years in the Canadian Arctic Archipelago: 2011 and 2012 eclipse 1998 and 2007

    Directory of Open Access Journals (Sweden)

    S. E. L. Howell

    2013-03-01

    Full Text Available Record low mean September sea ice area in the Canadian Arctic Archipelago (CAA was observed in 2011 (146 × 103 km2, a level that was nearly exceeded in 2012 (150 × 103 km2. These values eclipsed previous September records set in 1998 (200 × 103 km2 and 2007 (220 × 103 km2 and are ∼60% lower than the 1981–2010 mean September climatology. In this study, the driving processes contributing to the extreme light years of 2011 and 2012 were investigated, compared to previous extreme minima of 1998 and 2007, and contrasted against historic summer seasons with above average September ice area. The 2011 minimum was driven by positive July surface air temperature (SAT anomalies that facilitated rapid melt, coupled with atmospheric circulation in July and August that restricted multi-year ice (MYI inflow from the Arctic Ocean into the CAA. The 2012 minimum was also driven by positive July SAT anomalies (with coincident rapid melt but further ice decline was temporarily mitigated by atmospheric circulation in August and September which drove Arctic Ocean MYI inflow into the CAA. Atmospheric circulation was comparable between 2011 and 1998 (impeding Arctic Ocean MYI inflow and 2012 and 2007 (inducing Arctic Ocean MYI inflow. However, evidence of both preconditioned thinner Arctic Ocean MYI flowing into CAA and maximum landfast first-year ice (FYI thickness within the CAA was more apparent leading up to 2011 and 2012 than 1998 and 2007. The rapid melt process in 2011 and 2012 was more intense than observed in 1998 and 2007 because of the thinner ice cover being more susceptible to positive SAT forcing. The thinner sea ice cover within the CAA in recent years has also helped counteract the processes that facilitate extreme heavy ice years. The recent extreme light years within the CAA are associated with a longer navigation season within the Northwest Passage.

  11. Model simulated volume fluxes through the Canadian Arctic Archipelago and Davis Strait: Linking monthly variations to forcing in different seasons

    Science.gov (United States)

    Lu, Youyu; Higginson, Simon; Nudds, Shannon; Prinsenberg, Simon; Garric, Gilles

    2014-03-01

    The solution of a 10 year simulation of the Arctic Ocean, produced using a 6 km resolution coupled ocean and sea-ice model, is analyzed to understand the variability, control, and forcing mechanisms of the volume fluxes through the Canadian Arctic Archipelago (CAA) and Davis Strait (DS). The analysis focuses on variability at monthly time scales. Analysis confirms the "control" of volume fluxes through the CAA, proposed in previous studies, by (1) variations of sea surface height (SSH) in the "upstream" regions and the relationship of this control to alongshore wind in the Beaufort Sea and (2) by SSH in the "downstream" region in Baffin Bay that may be related to wind stress in Baffin Bay and the northern Labrador Sea. The effectiveness of these control and forcing mechanisms vary for fluxes through different sections and for different seasons. Variation of the southward flux through DS is directly influenced by fluxes through Nares Strait (NS) and Barrow Strait (BS) in summer, fall, and winter. In spring, variations of the southward and northward fluxes through DS are closely related to each other and correspond to changes in the SSH along pathways of the Irminger Current, and the East and West Greenland Currents.

  12. The flow of radionuclides through the Canadian archipelago

    International Nuclear Information System (INIS)

    The transport of contaminants to the Canadian Arctic by air and in water and their concentration through the marine food web has lead to enhanced levels of contaminants in several foods of Canadian northern inhabitants. Artificial radionuclides in the marine water can be used to determine water circulation and to trace contaminant transport through the Canadian Archipelago

  13. Isotopic analyses (18O, 13C, 14C) of two meromictic lakes in the Canadian Arctic Archipelago

    International Nuclear Information System (INIS)

    Meromictic Lakes Garrow and Sophia in the Canadian Arctic Archipelago were sampled to establish the origin and age of their waters by isotopic studies. The sigma/sub SMOW/18O values reflect the permanent stratification of the waters in both lakes. The mixolimnia contain waters with an isotopic signal between -13.16 and -2.198%, coherent with the values of precipitation in these high latitudes. The short residence time of the water in this layer makes it possible to record episodic variations of the freshwater inputs to the lakes. In the chemoclines, the sigma18O values increase to -10% concomitantly with a rise in chloride content to 42 g liter-1. This corresponds to a conservative mixing of surficial and deep waters. In the monimolimnia, hypersaline waters from brine production during permafrost growth in the watershed, according to a Rayleigh process. The brines drained toward the deepest part of each lake, after postglacial uplift, and became isolated. 14C dating of total inorganic carbon in the Lake Garrow monimolimnion gave an age of 2580 +/- 260 years B.P. In Lake Sophia, the deep waters exhibit recent 14C activity (121.4% modern carbon) that suggests recent infiltration of seawater into the lake basin

  14. Isotopic analyses (18O, 13C, 14C) of two meromictic lakes in the Canadian Arctic Archipelago

    International Nuclear Information System (INIS)

    Meromictic Lakes Garrow and Sophia in the Canadian Arctic Archipelago were sampled to establish the origin and age of their water by isotopic studies. 18O values reflect the permanent stratification of the water in both lakes. The mixolimnia contain waters with an isotopic signal between -13.16 and -21.98%, coherent with the values for precipitation in these high latitudes. In the chemoclines, the delta18O values increase to -10% concomitantly with a rise in chloride content to 42 g.liter-1. In the monimolimnia, hypersaline waters (up to 2.5 times the salinity of seawater) show negative delta18O values (ca. -.08%). These waters result from brine production during permafrost growth in the watershed, according to a Rayleigh process. 14C dating of total inorganic carbon in the Lake Garrow monimolimnion gave an age of 2580 +/- 260 years BP. In Lake Sophia, the deep waters exhibit recent 14C activity that suggests recent infiltration of seawater into the lake basin

  15. Biological and physical processes influencing sea ice, under-ice algae, and dimethylsulfoniopropionate during spring in the Canadian Arctic Archipelago

    Science.gov (United States)

    Galindo, V.; Levasseur, M.; Mundy, C. J.; Gosselin, M.; Tremblay, J.-É.; Scarratt, M.; Gratton, Y.; Papakiriakou, T.; Poulin, M.; Lizotte, M.

    2014-06-01

    This study presents temporal variations in concentrations of chlorophyll a (Chl a), particulate and dissolved dimethylsulfoniopropionate (DMSPp and DMSPd) in the sea ice and underlying water column in the Canadian Arctic Archipelago during the spring of 2010 and 2011. During both years, bottom ice Chl a, DMSPp and DMSPd concentrations were high (up to 1328 µg L-1, 15,082 nmol L-1, and 6110 nmol L-1, respectively) in May and decreased thereafter. The release of bottom ice algae and DMSPp in the water column was gradual in 2010 and rapid (8 days) in 2011. Bottom brine drainage during the presnowmelt period in 2010 and a rapid loss of the snow cover in 2011 coinciding with rain events explain most of the difference between the 2 years. During both years, less than 13% of the DMSPd lost from the ice was detected in the water column, suggesting a rapid microbial consumption. An under-ice diatom bloom developed in both years. In 2010, the bloom was dominated by centric diatoms while in 2011 pennates dominated, likely reflecting seeding by ice algae following the faster snowmelt progression induced by rainfall events in 2011. Both under-ice blooms were associated with high DMSPp concentrations (up to 185 nmol L-1), but pennate diatoms showed DMSPp/Chl a ratios twice higher than centrics. These results highlight the key role of snowmelt and precipitation on the temporal pattern of ice-DMSP release to the water column and on the timing, taxonomic composition, and DMSP content of phytoplankton under-ice blooms in the Arctic.

  16. A case study of old-ice import and export through Peary and Sverdrup Channels in the Canadian Arctic Archipelago: 1998-2005

    Science.gov (United States)

    Alt, Bea; Wilson, Katherine; Carrières, Tom

    This case study attempts to quantify the amount and timing of the import, export and through-flow of old ice in the Peary Channel-Sverdrup Channel area of the northern Canadian Arctic Archipelago during the period 1998-2005. The study combines quantitative weekly area-averaged ice coverage evaluations from the Canadian Ice Service (CIS) Digital Archive with detailed analysis of RADARSAT imagery and ice-motion results from the CIS ice-motion algorithm. The results show that in 1998 more than 70% of the old ice in Peary-Sverdrup was lost, half by melt and export to the south and the other half by export north into the Arctic Ocean, and that no Arctic Ocean old ice was imported into Peary-Sverdrup. A net import of 10% old ice was seen in 1999, with some indication of through-flow into southern channels. In 2000, no net import of old ice occurred in Peary-Sverdrup, but there was significant through-flow, with evidence of old ice reaching the Northwest Passage by November. Full recovery of the old-ice regime was complete by the end of 2001. More than two-thirds of the recovery was due to the in situ formation of second-year ice. Conditions in the following 3 years were near normal.

  17. Polarimetric C-/X-band Synthetic Aperture Radar Observations of Melting Sea Ice in the Canadian Arctic Archipelago

    Science.gov (United States)

    Casey, J. A.; Beckers, J. F.; Brossier, E.; Haas, C.

    2013-12-01

    Operational ice information services rely heavily on space-borne synthetic aperture radar (SAR) data for the production of ice charts to meet their mandate of providing timely and accurate sea ice information to support safe and efficient marine operations. During the summer melt period, the usefulness of SAR data for sea ice monitoring is limited by the presence of wet snow and melt ponds on the ice surface, which can mask the signature of the underlying ice. This is a critical concern for ice services whose clients (e.g. commercial shipping, cruise tourism, resource exploration and extraction) are most active at this time of year when sea ice is at its minimum extent, concentration and thickness. As a result, there is a need to further quantify the loss of ice information in SAR data during the melt season and to identify what information can still be retrieved about ice surface conditions and melt pond evolution at this time of year. To date the majority of studies have been limited to analysis of single-polarization C-band SAR data. This study will investigate the potential complimentary and unique sea ice information that polarimetric C- and X-band SAR data can provide to supplement the information available from traditional single co-polarized C-band SAR data. A time-series of polarimetric C- and X-band SAR data was acquired over Jones Sound in the Canadian Arctic Archipelago, in the vicinity of the Grise Fiord, Nunavut. Five RADARSAT-2 Wide Fine Quad-pol images and 11 TerraSAR-X StripMap dual-pol (HH/VV) images were acquired. The time-series begins at the onset of melt in early June and extends through advanced melt conditions in late July. Over this period several ponding and drainage events and two snowfall events occurred. Field observations of sea ice properties were collected using an Ice Mass Balance (IMB) buoy, hourly photos from a time-lapse camera deployed on a coastal cliff, and manual in situ measurements of snow thickness and melt pond depth

  18. Spatial and temporal trends of mercury and other metals in landlocked char from lakes in the Canadian Arctic archipelago

    International Nuclear Information System (INIS)

    Spatial and temporal trends of mercury (Hg) and 22 other elements were examined in landlocked Arctic char (Salvelinus alpinus) from six lakes in the Canadian Arctic (Char, Resolute and North Lakes, and Amituk Lake on Cornwallis Island, Sapphire Lake on Devon Island and Boomerang Lake on Somerset Island). The objectives of the study were to compare recent concentrations of Hg and other metals in char with older data from Amituk, Resolute and Char Lakes, in order to examine temporal trends as well as to investigate factors influencing spatial trends in contaminant levels such as lake characteristics, trophic position, size and age of the fish. Geometric mean Hg concentrations in dorsal muscle ranged from 0.147 μg/g wet weight (ww) in Resolute Lake to 1.52 μg/g ww in Amituk Lake for samples collected over the period 1999-2003. Char from Amituk Lake also had significantly higher selenium (Se). Mercury in char from Resolute Lake was strongly correlated with fish length, weight, and age, as well as with thallium, lead and Se. In 5 of 6 lakes, Hg concentrations were correlated with stable nitrogen isotope ratios (δ 15N) and larger char were feeding at a higher trophic level presumably due to feeding on smaller char. Weight adjusted mean Hg concentrations in char from Amituk Lake, and unadjusted geometric means in Char Lake and Resolute Lakes, did not show any statistically significant increase from the early 1990s to 2003. However, small sample sizes from 1999-2003 for fish 15N values best explained the higher concentrations of Hg in Amituk Lake compared to the other lakes

  19. Development and validation of a one-dimensional snow-ice algae model against observations in Resolute Passage, Canadian Arctic Archipelago

    Science.gov (United States)

    Pogson, L.; Tremblay, B.; Lavoie, D.; Michel, C.; Vancoppenolle, M.

    2011-04-01

    Ice algae are an important component of the carbon cycle in the Arctic. We investigate the dynamics of an ice algae bloom by coupling an ice algae-nutrient model with a multilayer σ coordinate thermodynamic sea ice model. The model is tested with the simulation of an algal bloom at the base of first-year ice over the spring. Model output is compared with data from Barrow Strait in the Canadian Arctic Archipelago. Snow cover, through its influence on ice melt, is a dominant factor controlling the decline of the bloom in the model, a finding that supports past studies. The results show that under a higher snow cover (20 cm), biomass in the early stages of the algal bloom is less than expected from the observed data. This discrepancy is due to the severely light-limited algal growth, despite the close match between simulated and observed under-ice photosynthetically active radiation. This result raises issues of how photosynthetic parameters as well as radiative transfer is represented in one-dimensional ice models. This study also shows that for higher algal concentrations, when biomass is split over multiple layers rather than concentrated in one layer at the ice base, there is a reduction in algae accumulation, a result of self shading. In addition, experiments show a sensitivity of total biomass to the oceanic heat flux and ice layer thickness, both of which affect biomass loss at the ice base. Being able to accurately model physical conditions is essential before the seasonal dynamics of ice algae can be accurately modeled, and some recommendations for improvement are discussed.

  20. Extensive sampling of polar bears (Ursus maritimus) in the Northwest Passage (Canadian Arctic Archipelago) reveals population differentiation across multiple spatial and temporal scales.

    Science.gov (United States)

    Campagna, Leonardo; Van Coeverden de Groot, Peter J; Saunders, Brenda L; Atkinson, Stephen N; Weber, Diana S; Dyck, Markus G; Boag, Peter T; Lougheed, Stephen C

    2013-09-01

    As global warming accelerates the melting of Arctic sea ice, polar bears (Ursus maritimus) must adapt to a rapidly changing landscape. This process will necessarily alter the species distribution together with population dynamics and structure. Detailed knowledge of these changes is crucial to delineating conservation priorities. Here, we sampled 361 polar bears from across the center of the Canadian Arctic Archipelago spanning the Gulf of Boothia (GB) and M'Clintock Channel (MC). We use DNA microsatellites and mitochondrial control region sequences to quantify genetic differentiation, estimate gene flow, and infer population history. Two populations, roughly coincident with GB and MC, are significantly differentiated at both nuclear (F ST = 0.01) and mitochondrial (ΦST = 0.47; F ST = 0.29) loci, allowing Bayesian clustering analyses to assign individuals to either group. Our data imply that the causes of the mitochondrial and nuclear genetic patterns differ. Analysis of mtDNA reveals the matrilineal structure dates at least to the Holocene, and is common to individuals throughout the species' range. These mtDNA differences probably reflect both genetic drift and historical colonization dynamics. In contrast, the differentiation inferred from microsatellites is only on the scale of hundreds of years, possibly reflecting contemporary impediments to gene flow. Taken together, our data suggest that gene flow is insufficient to homogenize the GB and MC populations and support the designation of GB and MC as separate polar bear conservation units. Our study also provide a striking example of how nuclear DNA and mtDNA capture different aspects of a species demographic history. PMID:24102001

  1. On the formulation of sea-ice models. Part 2: Lessons from multi-year adjoint sea-ice export sensitivities through the Canadian Arctic Archipelago

    Science.gov (United States)

    Heimbach, Patick; Menemenlis, Dimitris; Losch, Martin; Campin, Jean-Michel; Hill, Chris

    The adjoint of an ocean general circulation model is at the heart of the ocean state estimation system of the Estimating the Circulation and Climate of the Ocean (ECCO) project. As part of an ongoing effort to extend ECCO to a coupled ocean/sea-ice estimation system, a dynamic and thermodynamic sea-ice model has been developed for the Massachusetts Institute of Technology general circulation model (MITgcm). One key requirement is the ability to generate, by means of automatic differentiation (AD), tangent linear (TLM) and adjoint (ADM) model code for the coupled MITgcm ocean/sea-ice system. This second part of a two-part paper describes aspects of the adjoint model. The adjoint ocean and sea-ice model is used to calculate transient sensitivities of solid (ice and snow) freshwater export through Lancaster Sound in the Canadian Arctic Archipelago (CAA). The adjoint state provides a complementary view of the dynamics. In particular, the transient, multi-year sensitivity patterns reflect dominant pathways and propagation timescales through the CAA as resolved by the model, thus shedding light on causal relationships, in the model, across the Archipelago. The computational cost of inferring such causal relationships from forward model diagnostics alone would be prohibitive. The role of the exact model trajectory around which the adjoint is calculated (and therefore of the exactness of the adjoint) is exposed through calculations using free-slip vs no-slip lateral boundary conditions. Effective ice thickness, sea surface temperature, and precipitation sensitivities, are discussed in detail as examples of the coupled sea-ice/ocean and atmospheric forcing control space. To test the reliability of the adjoint, finite-difference perturbation experiments were performed for each of these elements and the cost perturbations were compared to those "predicted" by the adjoint. Overall, remarkable qualitative and quantitative agreement is found. In particular, the adjoint correctly

  2. VLF propagation measurements in the Canadian Arctic

    Science.gov (United States)

    Lauber, Wilfred R.; Bertrand, Jean M.

    1993-05-01

    For the past three years, during a period of high sun spot numbers, propagation measurements were made on the reception of VLF signals in the Canadian Arctic. Between Aug. and Dec. 1989, the received signal strengths were measured on the Canadian Coast Guard icebreaker, John A. MacDonald in the Eastern Canadian Arctic. Between Jul. 1991 and Jun. 1992, the received signal strengths were measured at Nanisivik, Baffin Island. The purposes of this work were to check the accuracy and estimate variances of the Naval Ocean Systems Center's (NOSC) Long Wave Propagation Capability (LWPC) predictions in the Canadian Arctic and to gather ionospheric storm data. In addition, the NOSC data taken at Fort Smith and our data at Nanisivik were used to test the newly developed Longwave Noise Prediction (LNP) program and the CCIR noise predictions, at 21.4 and 24.0 kHz. The results of the work presented and discussed in this paper show that in general the LWPC predicts accurate values of received signal strength in the Canadian Arctic with standard deviations of 1 to 2 dB over several months. Ionospheric storms can gauge the received signal strengths to decrease some 10 dB for a period of several hours or days. However, the effects of these storms are highly dependent on the propagation path. Finally the new LNP atmospheric noise model predicts lower values of noise in the Arctic than the CCIR model and our limited measurements tend to support these lower values.

  3. The Taimyr Peninsula and the Severnaya Zemlya archipelago, Arctic Russia

    DEFF Research Database (Denmark)

    Möller, Per; Alexanderson, Helena; Funder, Svend Visby;

    2015-01-01

    We here suggest a glacial and climate history of the Taimyr Peninsula and Severnaya Zemlya archipelago in arctic Siberia for the last about 150 000 years (ka). Primarily it is based on results from seven field seasons between 1996 and 2012, to a large extent already published in papers referred to...... in the text e and on data presented by Russian workers from the 1930s to our days and by German colleagues working there since the 1990s. Although glaciations even up here often started in the local mountains, their culminations in this region invariably seems to have centred on the shallow Kara Sea...

  4. Arctic response strategy: Canadian Coast Guard

    International Nuclear Information System (INIS)

    The revision of the Canadian Coast Guard's Arctic response strategy was described with particular focus on the consultative method used to ensure that all perspectives were taken into consideration. Some tankers used to re-supply fuel to remote Arctic communities carry more than 30,000 tonnes of product, putting them at risk for major spills. The Arctic response strategy was revised to emphasize recommendations for prevention, preparedness and response. Prevention was recognized as the most effective solution to oil spills in the Arctic. The leadership and coordination roles of the Canadian Coast Guard were demonstrated in relation to ship-source oil pollution. The new strategy also outlined the equipment requirements needed to respond to a large spill in the Arctic. Categorization of spill sizes as tier 1 to 4 was determined by examining southern regimes as was the characterization of corresponding equipment. Implementation of the new recommendations of the revised Arctic response strategy will take place over the next 2 years. The prevention aspect will include some legislative changes or stricter guidelines

  5. Arctic response strategy: Canadian Coast Guard

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, J.C. [Canadian Coast Guard, Sarnia, ON (Canada)

    2000-07-01

    The revision of the Canadian Coast Guard's Arctic response strategy was described with particular focus on the consultative method used to ensure that all perspectives were taken into consideration. Some tankers used to re-supply fuel to remote Arctic communities carry more than 30,000 tonnes of product, putting them at risk for major spills. The Arctic response strategy was revised to emphasize recommendations for prevention, preparedness and response. Prevention was recognized as the most effective solution to oil spills in the Arctic. The leadership and coordination roles of the Canadian Coast Guard were demonstrated in relation to ship-source oil pollution. The new strategy also outlined the equipment requirements needed to respond to a large spill in the Arctic. Categorization of spill sizes as tier 1 to 4 was determined by examining southern regimes as was the characterization of corresponding equipment. Implementation of the new recommendations of the revised Arctic response strategy will take place over the next 2 years. The prevention aspect will include some legislative changes or stricter guidelines.

  6. Evidence of recent changes in the ice regime of lakes in the Canadian High Arctic from spaceborne satellite observations

    OpenAIRE

    Cristina M. Surdu; Duguay, Claude R.; Fernández Prieto, Diego

    2016-01-01

    Arctic lakes, through their ice cover phenology, are a key indicator of climatic changes that the high-latitude environment is experiencing. In the case of lakes in the Canadian Arctic Archipelago (CAA), many of which are ice covered more than 10 months per year, warmer temperatures could result in ice regime shifts. Within the dominant polar-desert environment, small local warmer areas have been identified. These relatively small regions – polar oases – with longer growing ...

  7. Airborne organochlorines in the Canadian High Arctic

    OpenAIRE

    PATTON, G. W.; HINCKLEY, D. A.; Walla, M D; T. F. Bidleman; HARGRAVE, B. T.

    2011-01-01

    In 1984, the Canadian Polar Continental Shelf Project established a research camp on a floating ice island in the Beaufort Sea. The 7 × 4 km island is presently located about 50 km off Ellesmere Island at about 81°N, 100°W. Air samples of 1400–3000 m3 were collected on the island in August-September 1986 and June 1987, using a filter-solid adsorbent train. Organochlorines in melted snow and Arctic Ocean surface water were preconcentrated using solid adsorbent cartridges. Samples were analyzed...

  8. Late winter biogeochemical conditions under sea ice in the Canadian High Arctic

    Directory of Open Access Journals (Sweden)

    Helen S. Findlay

    2015-12-01

    Full Text Available With the Arctic summer sea-ice extent in decline, questions are arising as to how changes in sea-ice dynamics might affect biogeochemical cycling and phenomena such as carbon dioxide (CO2 uptake and ocean acidification. Recent field research in these areas has concentrated on biogeochemical and CO2 measurements during spring, summer or autumn, but there are few data for the winter or winter–spring transition, particularly in the High Arctic. Here, we present carbon and nutrient data within and under sea ice measured during the Catlin Arctic Survey, over 40 days in March and April 2010, off Ellef Ringnes Island (78° 43.11′ N, 104° 47.44′ W in the Canadian High Arctic. Results show relatively low surface water (1–10 m nitrate (<1.3 µM and total inorganic carbon concentrations (mean±SD=2015±5.83 µmol kg−1, total alkalinity (mean±SD=2134±11.09 µmol kg−1 and under-ice pCO2sw (mean±SD=286±17 µatm. These surprisingly low wintertime carbon and nutrient conditions suggest that the outer Canadian Arctic Archipelago region is nitrate-limited on account of sluggish mixing among the multi-year ice regions of the High Arctic, which could temper the potential of widespread under-ice and open-water phytoplankton blooms later in the season.

  9. Assessing regional populations of ground-nesting marine birds in the Canadian High Arctic

    Directory of Open Access Journals (Sweden)

    Mark Maftei

    2015-04-01

    Full Text Available The Queens Channel region of Nunavut is an ecologically distinct area within the Canadian High Arctic consisting of an extensive archipelago of small, low-lying gravel islands throughout which form several localized but highly productive polynyas. We used aerial survey and colony-monitoring data to assess regional- and colony-level fluctuations in the number of birds in this region between 2002 and 2013. Regional and colony-specific monitoring suggested that common eider (Somateria mollissima numbers are increasing, while numbers of Arctic terns (Sterna paradisaea may be in decline. Based on these data, we suggest that even infrequent comprehensive surveys are more useful than annual monitoring at specific sites in generating an accurate assessment of ground-nesting seabird populations at the regional level, and that dramatic fluctuations at individual colonies probably belie the overall stability of regional populations.

  10. Sea ice in the Canadian Arctic in the 21. century

    International Nuclear Information System (INIS)

    Climate warming will occur first and most intensely in Arctic regions, according to the numerical simulations of future climate performed with different Global Climate Models (GCMs). It includes the simulations performed by the Meteorological Service of Canada. The observations gathered in the Arctic indicate that the present warming has no precedent over the past four hundred years. Since the 1970s, data acquired mainly by satellite indicates that the extent of Arctic sea ice decreased at a rate of approximately three per cent per decade. Over the period 1969-2000, a similar rate of decrease has been observed within Canadian Arctic waters. Over the past forty years, estimates of the thickness of ice in the Arctic, based on submarine measurements, show a 40 per cent decrease. By 2050, if all the conditions remain as they are, the Arctic Ocean could be ice free. The most widely held scientific opinion seems to be that in the future there will be less ice in the Arctic than what was observed in the past, an opinion that is still being debated by scientists. The development of local natural resources and trans-shipment between Europe and Asia could increase dramatically in a future with less ice. Marine transportation in the Canadian Arctic would be expanded. Climatological analysis results of Canadian ice information is presented by the authors, and they have chosen to discuss various probable scenarios related to ice conditions during this century. 13 refs., 8 figs

  11. Biomarkers of Canadian High Arctic Litoral Sediments for Assessment of Organic Matter Sources and Degradation

    Science.gov (United States)

    Pautler, B. G.; Austin, J.; Otto, A.; Stewart, K.; Lamoureux, S. F.; Simpson, M. J.

    2009-05-01

    Carbon stocks in the High Arctic are particularly sensitive to global climate change, and investigation of variations in organic matter (OM) composition is beneficial for the understanding of the alteration of organic carbon under anticipated future elevated temperatures. Molecular-level characterization of solvent extractable compounds and CuO oxidation products of litoral sedimentary OM at the Cape Bounty Arctic Watershed Observatory in the Canadian Arctic Archipelago was conducted to determine the OM sources and decomposition patterns. The solvent extracts contained a series of aliphatic lipids, steroids and one triterpenoid primarily of higher plant origin and new biomarkers, iso- and anteiso-alkanes originating from cerastium arcticum (Arctic mouse-ear chickweed, a native angiosperm) were discovered. Carbon preference index (CPI) values for the n-alkanes, n-alkanols and n-alkanoic acids suggests that the OM biomarkers result from fresh material input in early stage of degradation. The CuO oxidation products were comprised of benzyls, lignin phenols and short-chain diacids and hydroxyacids. High abundance of terrestrial OM biomarkers observed at sites close to the river inlet suggests fluvial inputs as an important pathway to deliver OM into the lake. The lignin phenol vegetation index (LPVI) also suggests that the OM origin is mostly from non-woody angiosperms. A relatively high degree of lignin alteration in the litoral sediments is evident from the abundant ratio of acids and aldehydes of the vanillyl and syringyl monomers. This suggests that the lignin contents have been diagenetically altered as the result of a long residence time in this ecosystem. The molecular-level characterization of litoral sedimentary OM in Canadian High Arctic region provides insight into current OM composition,potential responses to future disturbances and the biogeochemical cycling of carbon in the Arctic.

  12. A Pliocene chronostratigraphy for the Canadian western and high Arctic

    Science.gov (United States)

    Gosse, John; Braschi, Lea; Rybczynski, Natalia; Lakeman, Thomas; Zimmerman, Susan; Finkel, Robert; Barendregt, Rene; Matthews, John

    2014-05-01

    The Beaufort Formation comprises an extensive (1200 km long, more than 1 km thick) clastic wedge that formed during the Pliocene along the western Canadian Arctic Archipelago (CAA). In the western Arctic, the Ballast Brook (BB) site on Banks Is. exposes more than 20 km of section through the sandy and pebble sandy braided stream deposits with detrital organic beds. Farther north, Beaufort Fm fluvial and estuarine facies have been examined on Meighen Is. In the high Arctic, high terrace gravels (450 m high surface) at the Fyles Leaf Bed (FLB) and Beaver Pond (BP) sites on Ellesmere Is. are not considered part of the Beaufort Fm but have similar paleoenvironmental records. Fossil plant and faunal material from these sediments is often very well preserved and provides evidence of a boreal-type forest and peatlands. The BP fossil site preserves the remains of fossil vertebrates including fish, frog, horse, beaver, deerlet, and black bear, consistent with a boreal type forest habitat. The FLB site has recently yielded the first fossil evidence for a High Arctic camel, identified with the help of collagen fingerprinting from a fragmentary limb bone (tibia). Paleoenvironmental reconstruction of the Ellesmere sites has yielded a Mean Annual Temperature of between 14 to 22 degrees Celsius warmer than today. Minimum cosmogenic nuclide burial ages of 3.4 and 3.8 Ma obtained for the BP and FLB sites, respectively, are consistent with vertebrate and floral biostratigraphic evidence. The paleoenvironmental records from the Beaufort Fm in the western CAA sites have revealed a similar ecosystem with noteworthy differences in MAT and perhaps seasonality. New burial ages from Meighen Is. indicate a maximum age of 6.1 Ma, consistent with yet much older than previous age estimates, but supportive of paleomagnetic and biostratigraphy at the same location. The age differences may account for some of the interpreted variations in paleoenvironments, in addition to spatial differences in

  13. Geothermal inversion of Canadian Arctic ground temperatures and effect of permafrost aggradation at emergent shorelines

    Science.gov (United States)

    Taylor, Alan E.; Wang, Kelin

    2008-07-01

    We apply traditional geothermal spectrum inversion to precision temperature logs and thermal conductivity from 10 wells in the Canadian Arctic Archipelago (75° to 81°N). Sites lie beyond the Holocene marine limit, and no effect of deep permafrost dynamics is expected. Ground surface temperature (GST) changes correlate with the Little Ice Age and Little Climatic Optimum with average amplitudes relative to 1980 of -2.7 K and +1.6 K, respectively. Results correlate broadly with similar reconstructions for this area and Greenland ice cap holes GRIP and Dye-3 to the southeast. An offshore site in 244 m water yields a Little Ice Age seabed temperature amplitude of -0.7 K, suggesting a moderated climate impact on regional ocean temperatures. Nearshore boreholes where permafrost is aggrading owing to glacioisostatic emergence are excluded; we demonstrate that traditional inversion codes without latent heat of phase change predict the magnitude of the emergence signal but a timing far too recent.

  14. The Pliocene High Arctic terrestrial palaeoenvironmental record and the development of the western Canadian Arctic coastal plain

    Science.gov (United States)

    Rybczynski, N.; Braschi, L.; Gosse, J. C.; Kennedy, C.; Fraser, D.; Lakeman, T.

    2013-12-01

    The Pliocene fossil record of the High Arctic is represented by a collection of sites that occur across the Canadian Arctic Archipelago (CAA), with deposits in the west comprising a 1200 km-long dissected clastic wedge (Beaufort Formation) and those in the east represented by high terrace gravel deposits. Fossil material from these sites is often very well preserved and provides evidence of a boreal-type forest. In the eastern Arctic our research sites includes the Fyles Leaf Bed (FLB) and the Beaver Pond (BP) sites, on west central Ellesmere Island. These are about 10 km apart and preserve evidence of forest and peatlands. The BP fossil site preserves the remains of fossil vertebrates including fish, frog, horse, beaver, deerlet, and black bear, consistent with a boreal type forest habitat. The FLB site has recently yielded the first fossil evidence for a High Arctic camel, identified with the help of collagen fingerprinting from a fragmentary limb bone (tibia). Although modern camels live in open habitats, biogeographic and comparative dental evidence, in combination, suggest that the North American Arctic camels were browsers, and therefore forest-dwelling. Paleoenvironmental reconstruction of the Ellesmere sites has yielded a Mean Annual Temperature of between 14 to 22 degrees Celsius warmer than today. Minimum cosmogenic nuclide burial ages of 3.4 and 3.8 Ma obtained for the BP and FLB sites, respectively, are consistent with vertebrate and floral biostratigraphic evidence. The Beaufort Formation, located in the Western CAA, was formed by a regional northwesterly flowing braided fluvial system. The Beaufort Formation appears to have filled at least the western portions of the 100 km-wide channels that currently separate the islands of the CAA. Intervals of Pliocene continental-shelf progradation are recorded in the lower Iperk Formation, which is situated offshore and includes complex sigmoid-oblique clinoforms indicative of high-energy, coarse

  15. Performance of municipal waste stabilization ponds in the Canadian Arctic

    DEFF Research Database (Denmark)

    Ragush, Colin M.; Schmidt, Jordan J.; Krkosek, Wendy H.;

    2015-01-01

    The majority of small remote communities in the Canadian arctic territory of Nunavut utilize waste stabilization ponds (WSPs) for municipal wastewater treatment because of their relatively low capital and operational costs, and minimal complexity. New national effluent quality regulations have been...... implemented in Canada, but not yet applied to Canada’s Arctic due to uncertainty related to the performance of current wastewater treatment systems. Waste stabilization pond (WSP) treatment performance is impacted by community water use, pond design, and climate. The greatest challenge arctic communities...... experience when using passive wastewater treatment technologies is the constraints imposed by the extreme climate, which is characterized as having long cold winters with short cool summers that can be solar intense. The removal of carbonaceous biochemical oxygen demand (CBOD5), total suspended solids (TSS...

  16. The Unexpected Re-Growth of Ice-Entombed Bryophytes in the Canadian High Arctic

    Science.gov (United States)

    La Farge, C.

    2014-12-01

    The rapid retreat of glaciers and ice caps throughout the Canadian Arctic is exposing pristine vegetation preserved beneath cold-based ice. For the past half century this vegetation has been consistently reported as dead. This interpretation has been overturned by the successful re-growth of Little Ice Age (1550-1850 AD) bryophytes emerging from the Teardrop Glacier, Sverdrup Pass, Ellesmere Island (79° N) collected in 2009. Some populations showed regeneration in the field and lab experiments confirmed their capacity to regrow. The species richness of these subglacial populations is exceptional, comprising >62 species that represent 44% of the extant bryophyte flora of Sverdrup Pass. Cold-based glaciers are known to provide critical habitats for a variety of microbiota (i.e., fungi, algae, cyanobacteria, bacteria and viruses) in high latitude ecosystems. The regeneration of Little Ice Age bryophytes fundamentally expands the concept of biological refugia to land plants that was previously restricted to survival above and beyond glacial margins. Given this novel understanding of subglacial ecosystems, fieldwork is now being extended southward to plateau ice caps on Baffin Island, Nunavut, where ice retreat is exposing subglacial populations of greater antiquity (thousands to tens of thousands of radiocarbon years before present). Bryophytes by nature are totipotent (stem cell equivalency) and poikilohydric (desiccation tolerance), which facilitate their unique adaptation to extreme environments. Continuity of the Arctic bryophyte flora extends back through the Holocene to the late Tertiary [Beaufort Fm, 2-5 Ma], when the majority of taxa were the same, based on records spanning the archipelago from Ellesmere to Banks Island. This record contrasts with that of vascular plants, which have had a number of extinctions, necessitating recolonization of arctic populations from outside the region. The biological significance of a stable bryophyte element highlights their

  17. Temporal and spatial variability in sea-ice carbon:nitrogen ratios on Canadian Arctic shelves

    Directory of Open Access Journals (Sweden)

    Andrea Niemi

    2015-12-01

    Full Text Available Abstract To enhance the accuracy of carbon cycling models as applied to sea ice in the changing Arctic, we analyzed a large data set of particulate organic carbon (POC and nitrogen (PON measurements in first-year bottom sea ice (n = 257 from two Arctic shelves, the Canadian Arctic Archipelago and Beaufort Sea shelf, including dark winter and spring seasonal measurements. Wide ranges of sea-ice POC:PON ratios were observed during both the dark winter (12–46 mol:mol and spring (3–24 mol:mol periods. Sea-ice POC:PON ratios and chlorophyll a concentrations were significantly higher in the Archipelago versus the Beaufort Sea shelf (p < 0.01, yet there was a highly significant relationship between sea-ice POC and PON during spring for both shelves (r2 = 0.94. POC:PON ratios were not consistent over the range of measured POC and PON concentrations, justifying the use of a power function model to best describe the relationship between POC and PON. Distinct relationships between POC:PON ratios and chlorophyll-based biomass were observed for the dark winter and the spring: dark winter sea-ice POC:PON ratios decreased with increasing sea-ice biomass whereas spring POC:PON ratios increased with increasing sea-ice biomass. The transition from the dark period to the spring growth period in first-year sea ice represented a distinct stoichiometric shift in POC:PON ratios. Our results demonstrate that the Redfield ratio has limited applicability over the four-order of magnitude range of biomass concentrations observed in first-year sea ice on Arctic shelves. This study emphasizes the need for variable POC:PON stoichiometry in sea-ice biogeochemical models and budget estimates, in particular at high biomass concentrations and when considering seasonality outside of the spring period in first year ice. The use of a power function model for POC:PON relationships in sea ice is also recommended to better constrain carbon estimates in biogeochemical sea-ice models.

  18. Ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Archipelago: Seasonal cycles and decadal trends

    Science.gov (United States)

    Harig, Christopher; Simons, Frederik J.

    2016-04-01

    Over the past several decades mountain glaciers and ice caps have been significant contributors to sea level rise. Here we estimate the ice mass changes in the Canadian Archipelago, the Gulf of Alaska, and Greenland since 2003 by analyzing time-varying gravimetry data from the Gravity Recovery and Climate Experiment. Prior to 2013, interannual ice mass variability in the Gulf of Alaska and in regions around Greenland remains within the average estimated over the whole data span. Beginning in summer 2013, ice mass in regions around Greenland departs positively from its long-term trend. Over Greenland this anomaly reached almost 500 Gt through the end of 2014. Overall, long-term ice mass loss from Greenland and the Canadian Archipelago continues to accelerate, while losses around the Gulf of Alaska region continue but remain steady with no significant acceleration.

  19. Photooxidation of dimethylsulfide (DMS in the Canadian Arctic

    Directory of Open Access Journals (Sweden)

    A. Taalba

    2013-02-01

    Full Text Available Photolysis of dimethylsulfide (DMS, a secondary photochemical process mediated by chromophoric dissolved organic matter (CDOM, has previously been demonstrated to be an important loss term of DMS in the surface layer of warm seas and the Southern Ocean. The role of photolysis in regulating the DMS dynamics in the Arctic Ocean, however, remains obscure. This study for the first time determined the apparent quantum yield (AQY spectra of DMS photooxidation in northern polar marine milieus covering the Baffin Bay in the eastern Canadian Arctic and the Mackenzie River estuary, Mackenzie Shelf and Canada Basin in the western Canadian Arctic. The DMS AQY was fairly invariant at salinities < 25 but rose rapidly with further increasing salinity, which is well defined by a three-parameter exponential decay equation with a constant intercept. Salinity can therefore be used as a quantitative indicator of the DMS AQY. The DMS AQY in the ultraviolet (UV wavelengths was linearly and positively correlated with the spectral slope coefficient (275–295 nm of the CDOM absorption spectrum, suggesting that marine CDOM photosensitizes the degradation of DMS more efficiently than does terrestrial CDOM. High concentrations of nitrate (~12 μmol L−1 in deep water samples boosted DMS photooxidation by 70–80%, due likely to radical chemistry of nitrate photolysis. Coupled optical-photochemical modeling, based on the obtained DMS AQY spectra, shows that UV-A (320–400 nm accounted for 60–75% of the DMS photolysis in the sunlit surface layer and that photochemistry degraded DMS on an e-folding time from 9 to 100 d (mean: 29 d. The photooxidation term on average accounted for 21% of the DMS gross loss rate and was comparable to the atmospheric DMS ventilation rate estimated for the same geographic regions.

  20. Some data on the polar bear and its utilization in the Canadian Arctic

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Some data have been collected on the polar bear kill and its utilization, based on information from 14 to 26 coastal settlements in the Canadian Arctic. Tt seems...

  1. Canadian Ice Service Arctic Regional Sea Ice Charts in SIGRID-3 Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Canadian Ice Service (CIS) produces digital Arctic regional sea ice charts for marine navigation, climate research, and input to the Global Digital Sea Ice Data...

  2. Carbon and Carbon Isotope Cycling in the Western Canadian Arctic

    Science.gov (United States)

    Mol, Jacoba; Thomas, Helmuth

    2016-04-01

    Increasing carbon dioxide levels in the atmosphere are having drastic effects on the global oceans. The Arctic Ocean is particularly susceptible to change as warming, sea-ice loss and a weak buffering capacity all influence this complicated semi-enclosed sea. In order to investigate the inorganic carbon system in the Canadian Arctic, water samples were collected in the Beaufort Sea, on the Alaskan shelf, at the Mackenzie river delta, and in Amundsen Gulf during the summer of 2014 and were analyzed for dissolved inorganic carbon (DIC), total alkalinity (TA), DI13C and 18O isotopes. Carbon isotopes are used to investigate the role of biological production on the uptake and transfer of inorganic carbon to depth. A preferential uptake of the lighter 12C relative to the heavier 13C isotope during biological production leads to a fractionation of the 13C/12C isotopes in both the organic matter and the water column. This results in an enrichment of DI13C in the high productivity surface waters and a depletion of DI13C at depth. Physical processes including freshwater input, brine rejection, and water mass mixing are investigated through the measurement of oxygen isotopes. Differences in the carbon system across the study area due to both biological and physical processes are assessed using depth profiles of DI13C and related carbon system parameters.

  3. Organochlorine contaminants in narwhal (Monodon monoceros) from the Canadian Arctic.

    Science.gov (United States)

    Muir, D C; Ford, C A; Grift, N P; Stewart, R E; Bidleman, T F

    1992-01-01

    Organochlorine pesticides (DDT, chlordane, polychlorinated camphenes (PCCs), dieldrin, hexachloroheclohexanes (SigmaHCH), mirex), polychlorinated biphenyl congeners (PCBs) and chlorobenzenes (SigmaCBz) were determined in blubber and liver of narwhal (Monodon monoceros) collected during 1982-1983 from Pond Inlet on northern Baffin Island in the Canadian Arctic. PCCs were the predominate organochlorines in narwhal blubber, ranging in concentration from 2990 to 13 200 ng g(-1) (wet wt) in males and from 1910 to 8390 ng g(-1) in females. PCCs consisted of two major components, an octachlorobornane and a nonachlorobornane with gas chromatographic retention times of 1.05 and 1.22, relative to 4,4'-DDE. SigmaPCB concentrations in blubber ranged from 2250 to 7290 ng g(-1) in males and from 894 to 5710 ng g(-1) in females. Seven PCB congeners (tetra-, penta- and hexachlorobiphenyls) accounted for 45% of total PCB (SigmaPCB) in narwhal blubber. Narwhal had 1.4- to 8.6-fold higher ratios of tetra- and pentachlorobiphenyls to PCB-153 (2,2',4,4',5,5'-hexachlorobiphenyl), lower 4,4'-DDE/SigmaDDT ratios and lower proportions of trans-nonachlor to total chlordane components than reported for odontocetes living in more contaminated environments. Mean SigmaPCB concentrations in narwhal were 6- to 15-fold lower than in dolphins from the Canadian east coast and belugas from the St Lawrence River estuary, respectively, while PCC levels were from 4- to about 2-fold lower, and SigmaHCH, dieldrin and SigmaCBz differed by <2-fold. The pattern of organochlorines in narwhal tissues suggests they are exposed to proportionally more volatile compounds, and may have less capacity to metabolize some of these compounds, relative to odontocetes living nearer sources of these contaminants. PMID:15092019

  4. The First Paleomagnetic data from the Cambrian basalts of Henrietta Island (De Long Archipelago, Arctic Ocean)

    Science.gov (United States)

    Metelkin, D. V.; Zhdanova, A.; Vernikovskiy, V. A.; Matushkin, N. Y.

    2015-12-01

    Henrietta Island in De Long archipelago (East-Siberian sea) still remains poorly studied geologically but last investigations show that its volcano-sedimentary sequences can help reconstruct tectonic evolution of East Russian Arctic in Early Paleozoic stage. The deposits lying on Precambrian basements are deformed to varying degrees and intruded by mafic dykes.The study was carried out on two basaltic lava flows whose 40Ar/39Ar age is 520.6±9.5 Ma. Previously the age of these basalts was assumed Cretaceous. According to available data the underlaying sediments contain zircons with Cambrian and Ordovician ages but all boundaries between these basalts and other strata are tectonic. So we suppose the age of basalts as Middle Cambrian but more precise geochronological data are required. All magnetic measurements were performed at the Laboratory of Geodynamics and Paleomagnetism of Institute of Petroleum Geology and Geophysics (Novosibirsk). Basalt samples has relatively high magnetic susceptibility values varying from 5x10-4 to 180x10-4SI units. NRM values range is from 3 to 170 mA/m. Petromagnetic parameters including also coercive characteristics point at the good potentially preserving primary magnetization. Stepwise thermal demagnetization permits to isolate characteristic components of magnetization and calculate mean directions in two lava flows: 1. Ds=294.3°, Is=29.1°, K=81.1, α95=5.1; 2. Ds=301.0°, Is=28.3°, K=34.4, α95=7.9). The mean paleomagnetic pole has coordinates: Plat=20.9°, Plong = 42.6°, dp/dm=14.3/7.9. Paleolatitude was defined as 15.3° but the question of the hemisphere for De Long Islands is open yet. In case of south hemisphere in Middle Cambrian according to available paleomagnetic data De Long islands could be placed close to Taimyr margin of Siberia and in case of northern hemisphere they may be located near south (in present-day coordinates) margin of Siberia. The work was supported by grant RFBR 14-05-31399 and Russian Research Fund

  5. Mercury in freshwater ecosystems of the Canadian Arctic: recent advances on its cycling and fate.

    Science.gov (United States)

    Chételat, John; Amyot, Marc; Arp, Paul; Blais, Jules M; Depew, David; Emmerton, Craig A; Evans, Marlene; Gamberg, Mary; Gantner, Nikolaus; Girard, Catherine; Graydon, Jennifer; Kirk, Jane; Lean, David; Lehnherr, Igor; Muir, Derek; Nasr, Mina; Poulain, Alexandre J; Power, Michael; Roach, Pat; Stern, Gary; Swanson, Heidi; van der Velden, Shannon

    2015-03-15

    The Canadian Arctic has vast freshwater resources, and fish are important in the diet of many Northerners. Mercury is a contaminant of concern because of its potential toxicity and elevated bioaccumulation in some fish populations. Over the last decade, significant advances have been made in characterizing the cycling and fate of mercury in these freshwater environments. Large amounts of new data on concentrations, speciation and fluxes of Hg are provided and summarized for water and sediment, which were virtually absent for the Canadian Arctic a decade ago. The biogeochemical processes that control the speciation of mercury remain poorly resolved, including the sites and controls of methylmercury production. Food web studies have examined the roles of Hg uptake, trophic transfer, and diet for Hg bioaccumulation in fish, and, in particular, advances have been made in identifying determinants of mercury levels in lake-dwelling and sea-run forms of Arctic char. In a comparison of common freshwater fish species that were sampled across the Canadian Arctic between 2002 and 2009, no geographic patterns or regional hotspots were evident. Over the last two to four decades, Hg concentrations have increased in some monitored populations of fish in the Mackenzie River Basin while other populations from the Yukon and Nunavut showed no change or a slight decline. The different Hg trends indicate that the drivers of temporal change may be regional or habitat-specific. The Canadian Arctic is undergoing profound environmental change, and preliminary evidence suggests that it may be impacting the cycling and bioaccumulation of mercury. Further research is needed to investigate climate change impacts on the Hg cycle as well as biogeochemical controls of methylmercury production and the processes leading to increasing Hg levels in some fish populations in the Canadian Arctic. PMID:24993511

  6. Three recent ice entrapments of Arctic cetaceans in West Greenland and the eastern Canadian High Arctic

    Directory of Open Access Journals (Sweden)

    MP Heide-Jørgensen

    2014-01-01

    Full Text Available Three ice entrapments of Monodontids have been reported in the western North Atlantic since 1993. Hunters in Disko Bay, West Greenland, discovered one in March 1994 that included about 150 narwhals (Monodon monoceros. The entrapment occurred during a sudden cold period which caused ice to form rapidly. The trapped whales were subject to hunting, but about 50 of the killed whales could not be retrieved in the ice. The whales were trapped in a small opening in the ice and because of that they would probably have succumbed even if not discovered by hunters. Two entrapments involving white whales or belugas (Delphinapterus leucas occurred in the eastern Canadian Arctic in May 1999; one in Lancaster Sound discovered by polar bear (Ursus maritimus researchers and one in Jones Sound discovered by hunters. The first included one bowhead whale (Balaena mysticetus and about 40 belugas that were being preyed upon by polar bears. The second involved at least 170 belugas, of which about 100 were killed by polar bears and 17 were taken by hunters. The entrapments in Disko Bay and Jones Sound both occurred in areas where entrapments have previously been reported, whereas the one in Lancaster Sound was in a new area.

  7. Inter- and intraclutch variation in egg mercury levels in marine bird species from the Canadian Arctic

    International Nuclear Information System (INIS)

    Mercury (Hg) is a toxic metal that has been of increasing concern in the Canadian Arctic. We measured total Hg in eggs of three marine birds (Arctic terns Sterna paradisaea, common eiders Somateria mollissima borealis, long-tailed ducks Clangula hyemalis) that breed in the Canadian Arctic, to compare Hg laying order effects from the same clutch and to examine Hg among species. Early-laid eggs of all three species had 24-48% higher Hg concentrations than late laid eggs. Arctic terns had approximately twice the concentration of Hg in their eggs as the two duck species, and Hg in eider eggs from the High Arctic was higher than Hg in eggs from the Low Arctic. Higher Hg in tern eggs was consistent with this species occupying a higher trophic position in marine food webs, as indicated by stable nitrogen isotope (δ15N) values. The egg-laying sequence may need to be considered for Hg biomonitoring studies where small samples sizes are planned, and early eggs may be preferable for such studies since early eggs may be more representative of potential maximum levels of Hg in the marine food webs.

  8. Evidence of recent changes in the ice regime of lakes in the Canadian High Arctic from spaceborne satellite observations

    Science.gov (United States)

    Surdu, Cristina M.; Duguay, Claude R.; Fernández Prieto, Diego

    2016-05-01

    Arctic lakes, through their ice cover phenology, are a key indicator of climatic changes that the high-latitude environment is experiencing. In the case of lakes in the Canadian Arctic Archipelago (CAA), many of which are ice covered more than 10 months per year, warmer temperatures could result in ice regime shifts. Within the dominant polar-desert environment, small local warmer areas have been identified. These relatively small regions - polar oases - with longer growing seasons and greater biological productivity and diversity are secluded from the surrounding barren polar desert. The ice regimes of 11 lakes located in both polar-desert and polar-oasis environments, with surface areas between 4 and 542 km2, many of unknown bathymetry, were documented. In order to investigate the response of ice cover of lakes in the CAA to climate conditions during recent years, a 15-year time series (1997-2011) of RADARSAT-1/2 ScanSAR Wide Swath, ASAR Wide Swath, and Landsat acquisitions were analyzed. Results show that melt onset occurred earlier for all observed lakes. With the exception of Lower Murray Lake, all lakes experienced earlier summer ice minimum and water-clear-of-ice (WCI) dates, with greater changes being observed for polar-oasis lakes (9-24 days earlier WCI dates for lakes located in polar oases and 2-20 days earlier WCI dates for polar-desert lakes). Additionally, results suggest that some lakes may be transitioning from a perennial/multiyear to a seasonal ice regime, with only a few lakes maintaining a multiyear ice cover on occasional years. Aside Lake Hazen and Murray Lakes, which preserved their ice cover during the summer of 2009, no residual ice was observed on any of the other lakes from 2007 to 2011.

  9. The alien terrestrial invertebrate fauna of the High Arctic archipelago of Svalbard: potential implications for the native flora and fauna

    Directory of Open Access Journals (Sweden)

    Stephen J. Coulson

    2015-09-01

    Full Text Available Experience from the Antarctic indicates that the establishment of alien species may have significant negative effects on native flora and fauna in polar regions and is considered to be amongst the greatest threats to biodiversity. But, there have been few similar studies from the Arctic. Although the terrestrial invertebrate inventory of the Svalbard Archipelago is amongst the most complete for any region of the Arctic, no consideration has yet been made of alien terrestrial invertebrate species, their invasiveness tendencies, threat to the native biology or their route of entry. Such baseline information is critical for appropriate management strategies. Fifteen alien invertebrate species have established in the Svalbard environment, many of which have been introduced via imported soils. Biosecurity legislation now prohibits such activities. None of the recorded established aliens yet show invasive tendencies but some may have locally negative effects. Ten species are considered to be vagrants and a further seven are classified as observations. Vagrants and the observations are not believed to be able to establish in the current tundra environment. The high connectivity of Svalbard has facilitated natural dispersal processes and may explain why few alien species are recorded compared to isolated islands in the maritime Antarctic. The vagrant species observed are conspicuous Lepidoptera, implying that less evident vagrant species are also arriving regularly. Projected climate change may enable vagrant species to establish, with results that are difficult to foresee.

  10. Spatial and temporal trends of contaminants in terrestrial biota from the Canadian Arctic

    International Nuclear Information System (INIS)

    Contaminants in the Canadian Arctic have been studied over the last twelve years under the guidance of the Northern Contaminants Program. This paper summarizes results from that program from 1998 to 2003 with respect to terrestrial animals in the Canadian Arctic. The arctic terrestrial environment has few significant contaminant issues, particularly when compared with freshwater and marine environments. Both current and historical industrial activities in the north may have a continuing effect on biota in the immediate area, but effects tend to be localized. An investigation of arctic ground squirrels at a site in the Northwest Territories that had historically received applications of DDT concluded that DDT in arctic ground squirrels livers was the result of contamination and that this is an indication of the continuing effect of a local point source of DDT. Arsenic concentrations were higher in berries collected from areas around gold mines in the Northwest Territories than from control sites, suggesting that gold mining may significantly affect arsenic levels in berries in the Yellowknives Dene traditional territory. Although moose and caribou from the Canadian Arctic generally carry relatively low contaminant burdens, Yukon moose had high renal selenium concentrations, and moose and some woodland caribou from the same area had high renal cadmium levels, which may put some animals at risk of toxicological effects. Low hepatic copper levels in some caribou herds may indicate a shortage of copper for metabolic demands, particularly for females. Similarities in patterns of temporal fluctuations in renal element concentrations for moose and caribou suggest that environmental factors may be a major cause of fluctuations in renal concentrations of some elements. Concentrations of persistent organochlorines and metals in beaver and muskrat from the Northwest Territories, and carnivores from across the Canadian Arctic were very low and considered normal for terrestrial

  11. The Drabo corymbosae-Papaveretea dahliani − a new vegetation class of the High Arctic polar deserts

    OpenAIRE

    Daniëls Fred J. A.; Elvebakk Arve; Matveyeva Nadezhda V.; Mucina Ladislav

    2016-01-01

    A new class and a new order (Drabo corymbosae-Papaveretea dahliani and Saxifrago oppositifoliae-Papaveretalia dahliani) have been described, and the Papaverion dahliani validated. This is vegetation of zonal habitats in lowlands of the High Arctic subzone A (or Arctic herb, cushion forb or polar desert subzone) and of ecologically equivalent sites at high altitudes on the mountain plateaus of the High Arctic. The new class spans three continents – North America (Canadian Arctic Archipelago an...

  12. Killer whale (Orcinus orca photo-identification in the eastern Canadian Arctic

    Directory of Open Access Journals (Sweden)

    Brent G. Young

    2011-05-01

    Full Text Available We identified individual killer whales (Orcinus orca using recent (2004–09 photographs to obtain a minimum count of whales that use eastern Canadian Arctic waters. Fifty-three individuals were identified from nine different sightings; 11 individuals from western Hudson Bay sightings and 42 from the areas around northern and eastern Baffin Island. One whale was re-sighted: an adult female or large juvenile photographed 17 days and 375 km apart at Churchill, Manitoba, and off-shore of Rankin Inlet, Nunavut, in August 2007. With only one individual re-sighted, the number of individuals that use this area is likely much larger. No re-sightings occurred between Arctic killer whales and individuals photographed off the coast of Newfoundland. Our results represent the minimum number of killer whales sighted in eastern Canadian Arctic waters and provide the foundation for further killer whale research. Little is known about Arctic killer whales and, as a top predator, it is unclear what effect they have on Arctic marine ecosystems.

  13. Small Thaw Ponds: An Unaccounted Source of Methane in the Canadian High Arctic

    OpenAIRE

    Karita Negandhi; Isabelle Laurion; Whiticar, Michael J; Pierre E Galand; Xiaomei Xu; Connie Lovejoy

    2013-01-01

    Thawing permafrost in the Canadian Arctic tundra leads to peat erosion and slumping in narrow and shallow runnel ponds that surround more commonly studied polygonal ponds. Here we compared the methane production between runnel and polygonal ponds using stable isotope ratios, ¹⁴C signatures, and investigated potential methanogenic communities through high-throughput sequencing archaeal 16S rRNA genes. We found that runnel ponds had significantly higher methane and carbon dioxide emissions, pro...

  14. Hybrid inventory, gravimetry and altimetry (HIGA) mass balance product for Greenland and the Canadian Arctic

    OpenAIRE

    Colgan, W.; W. Abdalati; Citterio, M.; Csatho, B.; X. Fettweis; Luthcke, S.; G. Moholdt; M. Stober

    2014-01-01

    We present a novel inversion algorithm that generates a mass balance field that is simultaneously consistent with independent observations of glacier inventory derived from optical imagery, cryosphere-attributed mass changes derived from satellite gravimetry, and ice surface elevation changes derived from airborne and satellite altimetry. We use this algorithm to assess mass balance across Greenland and the Canadian Arctic over the December 2003 to December ...

  15. Hybrid inventory, gravimetry and altimetry (HIGA mass balance product for Greenland and the Canadian Arctic

    Directory of Open Access Journals (Sweden)

    W. Colgan

    2014-01-01

    Full Text Available We present a novel inversion algorithm that generates a mass balance field that is simultaneously consistent with independent observations of glacier inventory derived from optical imagery, cryosphere-attributed mass changes derived from satellite gravimetry, and ice surface elevation changes derived from airborne and satellite altimetry. We use this algorithm to assess mass balance across Greenland and the Canadian Arctic over the December 2003 to December 2010 period at 26 km resolution. We assess a total mass loss of 316 ± 37 Gt a−1 over Greenland and the Canadian Arctic, with 217 ± 20 Gt a−1 being attributed to the Greenland Ice Sheet proper, and 38 ± 6 Gt a−1 and 50 ± 8 Gt a−1 being attributed to peripheral glaciers in Greenland and the Canadian Arctic, respectively. These absolute values are dependent on the gravimetry-derived spherical harmonic representation we invert. Our attempt to validate local values of algorithm-inferred mass balance reveals a paucity of in situ observations. At four sites, where direct comparison between algorithm-inferred and in situ mass balance is valid, we find an RMSD of 0.18 m WE a−1. Differencing algorithm-inferred mass balance with previously modelled surface mass balance, in order to solve the ice dynamic portion of mass balance as a residual, allows the transient glacier continuity equation to be spatially partitioned across Greenland.

  16. Prioritizing Climate Change Adaptations in Canadian Arctic Communities

    OpenAIRE

    Clara Champalle; Ford, James D; Mya Sherman

    2015-01-01

    Arctic regions are experiencing the most rapid climate change globally and adaptation has been identified as a priority across scales. Anticipatory planning to adapt to the impacts of climate change usually follows a number of steps: assess current and future vulnerability, identify potential adaptations, prioritize options, implement prioritized options, and monitor and evaluate implementation. While most of these steps are well documented, there has been limited examination of the process o...

  17. Photooxidation of dimethylsulfide (DMS) in the Canadian Arctic

    OpenAIRE

    A. Taalba; Xie, H.; Scarratt, M. G.; Bélanger, S.; Levasseur, M

    2013-01-01

    Photolysis of dimethylsulfide (DMS), a secondary photochemical process mediated by chromophoric dissolved organic matter (CDOM), has previously been demonstrated to be an important loss term of DMS in the surface layer of warm seas and the Southern Ocean. The role of photolysis in regulating the DMS dynamics in the Arctic Ocean, however, remains obscure. This study for the first time determined the apparent quantum yield (AQY) spectra of DMS photooxidation in northern polar marine milieus ...

  18. Photooxidation of dimethylsulfide (DMS) in the Canadian Arctic

    OpenAIRE

    A. Taalba; Xie, H.; Scarratt, M. G.; Bélanger, S.; Levasseur, M

    2013-01-01

    Photolysis of dimethylsulfide (DMS), a secondary photochemical process mediated by chromophoric dissolved organic matter (CDOM), has previously been demonstrated to be an important loss term of DMS in the surface layer of warm seas and the Southern Ocean. The role of photolysis in regulating the DMS dynamics in northern polar seas remains, however, less clear. This study for the first time determined the apparent quantum yield (AQY) spectra of DMS photooxidation in Canadian ...

  19. Facies patterns and conodont biogeography in Arctic Alaska and the Canadian Arctic Islands: Evidence against juxtaposition of these areas during early Paleozoic time

    Science.gov (United States)

    Dumoulin, J.A.; Harris, A.G.; Bradley, D.C.; De Freitas, T. A.

    2000-01-01

    Differences in lithofacies and biofacies suggest that lower Paleozoic rocks now exposed in Arctic Alaska and the Canadian Arctic Islands did not form as part of a single depositional system. Lithologic contrasts are noted in shallow- and deep-water strata and are especially marked in Ordovician and Silurian rocks. A widespread intraplatform basin of Early and Middle Ordovician age in northern Alaska has no counterpart in the Canadian Arctic, and the regional drowning and backstepping of the Silurian shelf margin in Canada has no known parallel in northern Alaska. Lower Paleozoic basinal facies in northern Alaska are chiefly siliciclastic, whereas resedimented carbonates are volumetrically important in Canada. Micro- and macrofossil assemblages from northern Alaska contain elements typical of both Siberian and Laurentian biotic provinces; coeval Canadian Arctic assemblages contain Laurentian forms but lack Siberian species. Siberian affinities in northern Alaskan biotas persist from at least Middle Cambrian through Mississippian time and appear to decrease in intensity from present-day west to east. Our lithologic and biogeographic data are most compatible with the hypothesis that northern Alaska-Chukotka formed a discrete tectonic block situated between Siberia and Laurentia in early Paleozoic time. If Arctic Alaska was juxtaposed with the Canadian Arctic prior to opening of the Canada basin, biotic constraints suggest that such juxtaposition took place no earlier than late Paleozoic time.

  20. The Drabo corymbosae-Papaveretea dahliani − a new vegetation class of the High Arctic polar deserts

    Directory of Open Access Journals (Sweden)

    Daniëls Fred J. A.

    2016-06-01

    Full Text Available A new class and a new order (Drabo corymbosae-Papaveretea dahliani and Saxifrago oppositifoliae-Papaveretalia dahliani have been described, and the Papaverion dahliani validated. This is vegetation of zonal habitats in lowlands of the High Arctic subzone A (or Arctic herb, cushion forb or polar desert subzone and of ecologically equivalent sites at high altitudes on the mountain plateaus of the High Arctic. The new class spans three continents – North America (Canadian Arctic Archipelago and Greenland, Europe (parts of Svalbard and Franz Josef Land, and Asia, including northern regions of Chelyuskin Peninsula (Taymir Peninsula, Severnaya Zemlya Archipelago and De Longa Islands.

  1. Relationship of cyanobacterial and algal assemblages with vegetation in the high Arctic tundra (West Spitsbergen, Svalbard Archipelago

    Directory of Open Access Journals (Sweden)

    Richter Dorota

    2015-09-01

    Full Text Available The paper presents the results of a study of cyanobacteria and green algae assemblages occurring in various tundra types determined on the basis of mosses and vascular plants and habitat conditions. The research was carried out during summer in the years 2009-2013 on the north sea-coast of Hornsund fjord (West Spitsbergen, Svalbard Archipelago. 58 sites were studied in various tundra types differing in composition of vascular plants, mosses and in trophy and humidity. 141 cyanobacteria and green algae were noted in the research area in total. Cyanobacteria and green algae flora is a significant element of many tundra types and sometimes even dominate there. Despite its importance, it has not been hitherto taken into account in the description and classification of tundra. The aim of the present study was to demonstrate the legitimacy of using phycoflora in supplementing the descriptions of hitherto described tundra and distinguishing new tundra types. Numeric hierarchical-accumulative classification (MVSP 3.1 software methods were used to analyze the cyanobacterial and algal assemblages and their co-relations with particular tundra types. The analysis determined dominant and distinctive species in the communities in concordance with ecologically diverse types of tundra. The results show the importance of these organisms in the composition of the vegetation of tundra types and their role in the ecosystems of this part of the Arctic.

  2. Overview and regional and temporal differences of heavy metals in Arctic whales and ringed seals in the Canadian Arctic.

    Science.gov (United States)

    Wagemann, R; Innes, S; Richard, P R

    1996-07-16

    Concentrations of mercury, cadmium, and other heavy metals in tissues of belugas (Delphinapterus leucas), narwhal (Monodon monoceros) and ringed seals (Phoca hispida) from across the Canadian Arctic are reported. Published and new information is used to provide an overview of metals in tissues of these animals, to delineate the existence of a spatial trend of mercury and cadmium in belugas and ringed seals, and to show a temporal trend is superimposed on the geochemical trend. Mercury concentrations in tissues of Arctic whales and ringed seals were high relative to the Canadian guideline of 0.5 micrograms/g wet wt., for mercury in fish, except in the skin of belugas (0.59-0.78 micrograms/g wet wt.) and flesh of ringed seals (0.39-0.41 micrograms/g wet wt.). In the flesh of belugas (0.94-1.34 micrograms/g wet wt.), and in the liver of ringed seals, tissues that are also consumed by Native people in the Arctic (8.34-27.5 micrograms/g wet wt.), the guideline value was significantly exceeded. Mean lead concentrations in tissues of belugas, narwhal and ringed seals were generally low (0.002-0.028 micrograms/g wet wt.), except in tissues of belugas in the St. Lawrence River (0.10-0.15 micrograms/g wet wt.). The concentration of zinc in the skin of whales was two to three times higher than in other tissues. The concentration of cadmium in organs was highest in narwhal. There was a positive correlation between mercury and selenium in the liver of all three species. The concentration of mercury in tissues of belugas and ringed seals was higher in the western than the eastern Arctic. This was attributed to different natural background concentrations in the western and eastern Arctic of Canada dictated by different geological formations in the two regions. Cadmium concentrations in tissues of belugas and ringed seals were higher in the eastern than the western Arctic. Zinc and copper in some tissues of belugas and ringed seals were also higher in the eastern than the western

  3. An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife.

    Science.gov (United States)

    Fisk, Aaron T; de Wit, Cynthia A; Wayland, Mark; Kuzyk, Zou Zou; Burgess, Neil; Letcher, Robert; Braune, Birgit; Norstrom, Ross; Blum, Susan Polischuk; Sandau, Courtney; Lie, Elisabeth; Larsen, Hans Jørgen S; Skaare, Janneche Utne; Muir, Derek C G

    2005-12-01

    Anthropogenic contaminants have been a concern in the Canadian arctic for over 30 years due to relatively high concentrations of bioaccumulating and biomagnifying organochlorine contaminants (OCs) and toxic metals found in some arctic biota and humans. However, few studies have addressed the potential effects of these contaminants in Canadian arctic wildlife. Prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects related to contaminant exposure, and compares new tissue concentration data to threshold effects levels. Weak relationships between cadmium, mercury and selenium burdens and health biomarkers in common eider ducks (Somateria mollissima borealis) in Nunavut were found but it was concluded that metals were not influencing the health of these birds. Black guillemots (Cepphus grylle) examined near PCB-contaminated Saglek Bay, Labrador, had enlarged livers, elevated EROD and liver lipid levels and reduced retinol (vitamin A) and retinyl palmitate levels, which correlated to PCB levels in the birds. Circulating levels of thyroid hormones in polar bears (Ursus maritimus) were correlated to PCB and HO-PCB plasma concentrations, but the impact at the population level is unknown. High PCB and organochlorine pesticide concentrations were found to be strongly associated with impaired humoral and cell-mediated immune responses in polar bears, implying an increased infection risk that could impact the population. In beluga whale (Delphinapterus leucas), cytochromes P450 (phase I) and conjugating (phase II) enzymes have been extensively profiled (immunochemically and catalytically) in liver, demonstrating the importance of contaminants in relation to enzyme induction, metabolism and potential contaminant bioactivation and fate. Concentrations of OCs and metals in arctic terrestrial wildlife, fish and seabirds are generally below effects thresholds

  4. An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife

    International Nuclear Information System (INIS)

    Anthropogenic contaminants have been a concern in the Canadian arctic for over 30 years due to relatively high concentrations of bioaccumulating and biomagnifying organochlorine contaminants (OCs) and toxic metals found in some arctic biota and humans. However, few studies have addressed the potential effects of these contaminants in Canadian arctic wildlife. Prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects related to contaminant exposure, and compares new tissue concentration data to threshold effects levels. Weak relationships between cadmium, mercury and selenium burdens and health biomarkers in common eider ducks (Somateria mollissima borealis) in Nunavut were found but it was concluded that metals were not influencing the health of these birds. Black guillemots (Cepphus grylle) examined near PCB-contaminated Saglek Bay, Labrador, had enlarged livers, elevated EROD and liver lipid levels and reduced retinol (vitamin A) and retinyl palmitate levels, which correlated to PCB levels in the birds. Circulating levels of thyroid hormones in polar bears (Ursus maritimus) were correlated to PCB and HO-PCB plasma concentrations, but the impact at the population level is unknown. High PCB and organochlorine pesticide concentrations were found to be strongly associated with impaired humoral and cell-mediated immune responses in polar bears, implying an increased infection risk that could impact the population. In beluga whale (Delphinapterus leucas), cytochromes P450 (phase I) and conjugating (phase II) enzymes have been extensively profiled (immunochemically and catalytically) in liver, demonstrating the importance of contaminants in relation to enzyme induction, metabolism and potential contaminant bioactivation and fate. Concentrations of OCs and metals in arctic terrestrial wildlife, fish and seabirds are generally below effects thresholds

  5. An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, Aaron T. [Warnell School of Forest Resources, University of Georgia, Athens, GA 30602-2152 (United States)]. E-mail: afisk@forestry.uga.edu; Wit, Cynthia A. de [Department of Applied Environmental Science, Stockholm University, Stockholm (Sweden); Wayland, Mark [Prairie and Northern Wildlife Research Centre, Environment Canada, 115 Perimeter Rd., Saskatoon, SK, S7N 0X4 (Canada); Kuzyk, Zou Zou [Environmental Sciences Group, Royal Military College of Canada, Kingston, ON, K7K 7B4 (Canada); Burgess, Neil [Canadian Wildlife Service, Environment Canada, 6 Bruce St. Mt. Pearl, NL, A1N4T3 (Canada); Letcher, Robert [National Wildlife Research Centre, Environment Canada, Ottawa, ON, K1A 0H3 (Canada); Braune, Birgit [National Wildlife Research Centre, Environment Canada, Ottawa, ON, Canada K1A 0H3 (Canada); Norstrom, Ross [National Wildlife Research Centre, Environment Canada, Ottawa, ON, K1A 0H3 (Canada); Blum, Susan Polischuk [Office of Research Services, University of Saskatchewan, Saskatoon, SK, S7N 4J8 (Canada); Sandau, Courtney [Jacques Whitford Limited, Calgary, AB, T2R 0E4 (Canada); Lie, Elisabeth [National Veterinary Institute, P.O. Box 8156, Dep 0033, Oslo (Norway); Larsen, Hans Jorgen S. [Norwegian School of Veterinary Science, P.O. Box 8146, Dep 0033, Oslo (Norway); Skaare, Janneche Utne [National Veterinary Institute, P.O. Box 8156, Dep 0033, Oslo (Norway); Norwegian School of Veterinary Science, P.O. Box 8146, Dep 0033, Oslo (Norway); Muir, Derek C.G. [National Water Research Institute, Environment Canada, Burlington, ON, L7R 4A6 (Canada)

    2005-12-01

    Anthropogenic contaminants have been a concern in the Canadian arctic for over 30 years due to relatively high concentrations of bioaccumulating and biomagnifying organochlorine contaminants (OCs) and toxic metals found in some arctic biota and humans. However, few studies have addressed the potential effects of these contaminants in Canadian arctic wildlife. Prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects related to contaminant exposure, and compares new tissue concentration data to threshold effects levels. Weak relationships between cadmium, mercury and selenium burdens and health biomarkers in common eider ducks (Somateria mollissima borealis) in Nunavut were found but it was concluded that metals were not influencing the health of these birds. Black guillemots (Cepphus grylle) examined near PCB-contaminated Saglek Bay, Labrador, had enlarged livers, elevated EROD and liver lipid levels and reduced retinol (vitamin A) and retinyl palmitate levels, which correlated to PCB levels in the birds. Circulating levels of thyroid hormones in polar bears (Ursus maritimus) were correlated to PCB and HO-PCB plasma concentrations, but the impact at the population level is unknown. High PCB and organochlorine pesticide concentrations were found to be strongly associated with impaired humoral and cell-mediated immune responses in polar bears, implying an increased infection risk that could impact the population. In beluga whale (Delphinapterus leucas), cytochromes P450 (phase I) and conjugating (phase II) enzymes have been extensively profiled (immunochemically and catalytically) in liver, demonstrating the importance of contaminants in relation to enzyme induction, metabolism and potential contaminant bioactivation and fate. Concentrations of OCs and metals in arctic terrestrial wildlife, fish and seabirds are generally below effects thresholds

  6. The Endangered Arctic, the Arctic as Resource Frontier: Canadian News Media Narratives of Climate Change and the North.

    Science.gov (United States)

    Stoddart, Mark C J; Smith, Jillian

    2016-08-01

    The Arctic is one of the most radically altered parts of the world due to climate change, with significant social and cultural impacts as a result. Using discourse network analysis and qualitative textual analysis of articles published in the Globe and Mail and National Post during the period 2006 to 2010, we identify and analyze key frames that interpret the implications of climate change on the Arctic. We examine Canadian national news media coverage to ask: How does the Arctic enter media coverage of climate change? Is there evidence of a climate justice discourse in relation to regional disparities in the risks and harms of climate change between northern and southern Canada? Climate change in the Arctic is often framed through the lens of Canadian national interests, which downplays climate-related social impacts that are already occurring at subnational political and geographical scales. L'Arctique est une des régions du monde la plus radicalement altérée par le changement climatique, menant comme résultat des importants changements sociaux et culturels. En utilisant l'analyse des réseaux de discours ainsi que l'analyse textuelle qualitative des articles publiés dans le Globe and Mail et le National Post de 2006 à 2010, nous identifions and analysons des cadres clés qui servent à interpréter les conséquences du changement climatique dans l'Arctique. Nous examinons la couverture des médias nationaux canadiens pour pouvoir demander : comment est-ce que l'Arctique s'insère dans la couverture médiatique du changement climatique? Est-ce qu'il y a de la preuve d'un discours de la justice climatique en relation des disparités régionales des risques et méfaits du changement climatique entre le Canada du nord et du sud? Le changement climatique dans l'Arctique est souvent encadré à travers le prisme des intérêts nationaux canadiens, ce qui minimise les impacts sociaux reliés au climat qui se produisent actuellement aux échelons sous

  7. Hybrid inventory, gravimetry and altimetry (HIGA) mass balance product for Greenland and the Canadian Arctic

    DEFF Research Database (Denmark)

    Colgan, W.; Abdalati, W.; Citterio, M.;

    2015-01-01

    We present a novel inversion algorithm that generates a mass balance field that is simultaneously consistent with independent observations of glacier inventory derived from optical imagery, cryosphere-attributed mass trends derived from satellite gravimetry, and ice surface elevation trends derived...... from airborne and satellite altimetry. We use this algorithm to assess mass balance across Greenland and the Canadian Arctic over the Sep-2003 to Oct-2009 period at 26 km resolution. We evaluate local algorithm-inferred mass balance against forty in situ point observations. This evaluation yields an...... Arctic. These magnitudes of mass loss are dependent on the gravimetry-derived spherical harmonic mass trend we invert. We spatially partition the transient glacier continuity equation by differencing algorithm-inferred mass balance from modeled surface mass balance, in order to solve the horizontal...

  8. Trophodynamics of some PFCs and BFRs in a western Canadian Arctic marine food web.

    Science.gov (United States)

    Tomy, Gregg T; Pleskach, Kerri; Ferguson, Steve H; Hare, Jonathon; Stern, Gary; Macinnis, Gordia; Marvin, Chris H; Loseto, Lisa

    2009-06-01

    The trophodynamics of per- and polyfluorinated compounds and bromine-based flame retardants were examined in components of a marine food web from the western Canadian Arctic. The animals studied and their relative trophic status in the food web, established using stable isotopes of nitrogen (delta15N), were beluga (Delphinapterus leucas) > ringed seal (Phoca hispida) > Arctic cod (Boreogadus saida) > Pacific herring (Clupea pallasi) approximately equal to Arctic cisco (Coregonus autumnalis) > pelagic amphipod (Themisto libellula) > Arctic copepod (Calanus hyperboreus). For the brominated diphenyl ethers, the lipid adjusted concentrations of the seven congeners analyzed (Sigma7BDEs: -47, -85, -99, -100, -153, -154, and -209) ranged from 205.4 +/- 52.7 ng/g in Arctic cod to 2.6 +/- 0.4 ng/g in ringed seals. Mean Sigma7BDEs concentrations in Arctic copepods, 16.4 ng/g (n = 2, composite sample), were greater than those in the top trophic level (TL) marine mammals and suggests that (i) Arctic copepods are an important dietary component that delivers BDEs to the food web and (ii) because these compounds are bioaccumulative, metabolism and depletion of BDE congeners in top TL mammals is an important biological process. There were differences in the concentration profiles of the isomers of hexabromocyclododecane (HBCD) in the food web. The most notable difference was observed for beluga, where the alpha-isomer was enriched (accounting for approximately 90% of the SigmaHBCD body burden), relative to its primary prey species, Arctic cod, where the alpha-isomer accounted for only 20% of the SigmaHBCD body burden (beta: 4% and gamma: 78%). For the C8-C11 perfluorinated carboxylic acids, the trophic magnification factors (TMFs) were all greater than unity and increased with increasing carbon chain length. PFOS and its neutral precursor, PFOSA, also had TMF values greater than one. There were also pronounced differences in the PFOSA to PFOS ratio in ringed seal (0.04) and in

  9. Dissolved organic matter photolysis in Canadian arctic thaw ponds

    International Nuclear Information System (INIS)

    The abundant thaw lakes and ponds in the circumarctic receive a new pool of organic carbon as permafrost peat soils degrade, which can be exposed to significant irradiance that potentially increases as climate warms and ice cover shortens. Exposure to sunlight is known to accelerate the transformation of dissolved organic matter (DOM) into molecules that can be more readily used by microbes. We sampled the water from two common classes of ponds found in the ice-wedge system of continuous permafrost regions of Canada, polygonal and runnel ponds, and followed the transformation of DOM over 12 days by looking at dissolved organic carbon (DOC) concentration and DOM absorption and fluorescence properties. The results indicate a relatively fast decay of color (3.4 and 1.6% loss d−1 of absorption at 320 nm for the polygonal and runnel pond, respectively) and fluorescence (6.1 and 8.3% loss d−1 of total fluorescent components, respectively) at the pond surface, faster in the case of humic-like components, but insignificant losses of DOC over the observed period. This result indicates that direct DOM mineralization (photochemical production of CO2) is apparently minor in thaw ponds compared to the photochemical transformation of DOM into less chromophoric and likely more labile molecules with a greater potential for microbial mineralization. Therefore, DOM photolysis in arctic thaw ponds can be considered as a catalytic mechanism, accelerating the microbial turnover of mobilized organic matter from thawing permafrost and the production of greenhouse gases, especially in the most shallow ponds. Under a warming climate, this mechanism will intensify as summers lengthen. (letter)

  10. The role of seasonal migration in the near-total loss of caribou on south-central Canadian Arctic Islands

    OpenAIRE

    Frank L. Miller; Samuel J. Barry; Wendy A. Calvert

    2007-01-01

    Extended: In 1980 the caribou (Rangifer tarandus) on Prince of Wales, Russell, and Somerset islands represented a healthy geographic population of an Arctic-island caribou ecotype on the southern tier of Canadian Arctic Islands. Those caribou exhibited complex patterns of seasonal range occupancy, involving annual seasonal migrations between and among the three islands and Boothia Peninsula (Miller et al., 1982, 2005; Miller, 1990). A large segment of the population migrated annually from the...

  11. Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2

    OpenAIRE

    Chylek, P.; Li, J.; Dubey, M. K.; Wang, M.; Lesins, G.

    2011-01-01

    We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2). The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and the intervening 1940–1970 period of substantial cooling. The add...

  12. Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2

    OpenAIRE

    Chylek, P.; Li, J.; Dubey, M. K.; Wang, M.; Lesins, G.

    2011-01-01

    We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2). The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and the intervening 1940–1970 period of substantia...

  13. A catch history for Atlantic walruses (Odobenus rosmarus rosmarus in the eastern Canadian Arctic

    Directory of Open Access Journals (Sweden)

    D Bruce Stewart

    2014-08-01

    Full Text Available Knowledge of changes in abundance of Atlantic walruses (Odobenus rosmarus rosmarus in Canada is important for assessing their current population status. This catch history collates available data and assesses their value for modelling historical populations to inform population recovery and management. Pre-historical (archaeological, historical (e.g., Hudson Bay Company journals and modern catch records are reviewed over time by data source (whaler, land-based commercial, subsistence etc. and biological population or management stock.Direct counts of walruses landed as well as estimates based on hunt products (e.g., hides, ivory or descriptors (e.g., Peterhead boatloads support a minimum landed catch of over 41,300 walruses in the eastern Canadian Arctic between 1820 and 2010. Little is known of Inuit catches prior to 1928, despite the importance of walruses to many Inuit groups for subsistence. Commercial hunting from the late 1500s to late 1700s extirpated the Atlantic walrus from Quebec and the Atlantic Provinces, but there was no commercial hunt for the species in the Canadian Arctic until ca. 1885. As the availability of bowhead whale (Balaena mysticetus declined, whalers increasingly turned to hunting other species, including walruses. Modest numbers (max. 278/yr were taken from the High Arctic population in the mid-1880s and large catches (up to 1400/yr were often taken from the Central Arctic population from 1899 -1911, while the Foxe Basin stock (Central Arctic population and Low Arctic population were largely ignored by commercial hunters. Land-based traders (ca. 1895-1928 continued the commercial hunt until regulatory changes in 1928 reserved walruses for Inuit use. Since 1950, reported walrus catches have been declining despite a steady increase in the Inuit population. Effort data are needed to assess whether lower catches stem from declining hunter effort or decreased walrus abundance. The recent take of walruses by sport hunting

  14. Persistent halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis) from the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Braune, Birgit M., E-mail: birgit.braune@ec.gc.c [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, K1A 0H3 (Canada); Mallory, Mark L. [Environment Canada, Box 1714, Iqaluit, Nunavut, X0A 0H0 (Canada); Butt, Craig M.; Mabury, Scott A. [Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6 (Canada); Muir, Derek C.G. [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario, L7R 4A6 (Canada)

    2010-12-15

    Northern fulmars from two breeding colonies in the Canadian Arctic, Cape Vera and Prince Leopold Island, were analyzed for organochlorine pesticides, PCBs, perfluorinated compounds (PFCs) and total mercury (Hg). Hepatic concentrations of organochlorines and Hg were highest in the male fulmars from Cape Vera. Perfluorooctane sulfonate (PFOS) concentrations did not vary significantly between sexes or colonies. However, concentrations of the perfluorinated carboxylates (PFCAs) were higher in fulmars from Cape Vera than Prince Leopold Island. The C{sub 11}-C{sub 15} PFCAs averaged 90% of the PFCA profile at both colonies. Polychorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs (NO-PCBs) were measured only in birds from Prince Leopold Island. Concentrations of PCDDs, PCDFs, NO-PCBs and Toxic Equivalents (TEQs) did not differ significantly between sexes. {Sigma}TEQ was comprised mainly of {Sigma}TEQ{sub PCDF}. Concentrations of Hg and the persistent halogenated compounds reported in this study were below published toxicological threshold values for wild birds. - Northern fulmars in the Canadian Arctic demonstrate sex-specific, colony-specific, and regional differences in contaminant profiles.

  15. Persistent halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis) from the Canadian Arctic

    International Nuclear Information System (INIS)

    Northern fulmars from two breeding colonies in the Canadian Arctic, Cape Vera and Prince Leopold Island, were analyzed for organochlorine pesticides, PCBs, perfluorinated compounds (PFCs) and total mercury (Hg). Hepatic concentrations of organochlorines and Hg were highest in the male fulmars from Cape Vera. Perfluorooctane sulfonate (PFOS) concentrations did not vary significantly between sexes or colonies. However, concentrations of the perfluorinated carboxylates (PFCAs) were higher in fulmars from Cape Vera than Prince Leopold Island. The C11-C15 PFCAs averaged 90% of the PFCA profile at both colonies. Polychorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs (NO-PCBs) were measured only in birds from Prince Leopold Island. Concentrations of PCDDs, PCDFs, NO-PCBs and Toxic Equivalents (TEQs) did not differ significantly between sexes. ΣTEQ was comprised mainly of ΣTEQPCDF. Concentrations of Hg and the persistent halogenated compounds reported in this study were below published toxicological threshold values for wild birds. - Northern fulmars in the Canadian Arctic demonstrate sex-specific, colony-specific, and regional differences in contaminant profiles.

  16. Pollution in the Summertime Canadian High Arctic observed during NETCARE 2014: Investigation of origin and composition

    Science.gov (United States)

    Köllner, Franziska; Schneider, Johannes; Bozem, Heiko; Hoor, Peter; Willis, Megan; Burkart, Julia; Leaitch, Richard; Abbatt, Jon; Herber, Andreas; Borrmann, Stephan

    2015-04-01

    The clean and sensitive Arctic atmosphere is influenced by transport of air masses from lower latitudes that bring pollution in the form of aerosol particles and trace gases into the Arctic regions. However, the transport processes causing such pollution events are yet not sufficiently well understood. Here we report on results from the aircraft campaign NETCARE 2014 that took place in July 2014 in Resolute Bay, Nunavut (Canada) as part of the "Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environment" (NETCARE). These airborne measurements add to only a very few of such measurements conducted in the Arctic during the summertime. The instrumentation on board the research aircraft Polar 6 (operated by the Alfred Wegener Institute for Polar and Marine Research) included a large set of physico-chemical aerosol analysis instruments, several trace gas measurements and basic meteorological parameters. Here we focus on observed pollution events that caused elevated trace gas and aerosol concentrations in the summertime Canadian High Arctic between 50 and 3500 m. In order to better understand the chemical composition and the origin of those polluted air masses, we use single particle aerosol composition obtained using the Aircraft-based Laser Ablation Aerosol Mass Spectrometer (ALABAMA), combined with aerosol size distributions and number concentrations from an Optical Particle Counter as well as trace gas measurements of CO and CO2. CO and CO2 are important tracers to study pollution events, which are connected to anthropogenic and non-anthropogenic combustion processes, respectively biomass burning and fossil fuel combustion. The ALABAMA provides a detailed single particle aerosol composition analysis from which we identify different particle types like soot-, biomass burning-, organics-, diesel exhaust- and metallic particles. The measurements were compared to Lagrangian models like FLEXPART and LAGRANTO to find the pollution sources

  17. Photodemethylation of Methylmercury in Eastern Canadian Arctic Thaw Pond and Lake Ecosystems.

    Science.gov (United States)

    Girard, Catherine; Leclerc, Maxime; Amyot, Marc

    2016-04-01

    Permafrost thaw ponds of the warming Eastern Canadian Arctic are major landscape constituents and often display high levels of methylmercury (MeHg). We examined photodegradation potentials in high-dissolved organic matter (DOC) thaw ponds on Bylot Island (BYL) and a low-DOC oligotrophic lake on Cornwallis Island (Char Lake). In BYL, the ambient MeHg photodemethylation (PD) rate over 48 h of solar exposure was 6.1 × 10(-3) m(2) E(-1), and the rate in MeHg amended samples was 9.3 × 10(-3) m(2) E(-1). In contrast, in low-DOC Char Lake, PD was only observed in the first 12 h, which suggests that PD may not be an important loss process in polar desert lakes. Thioglycolic acid addition slowed PD, while glutathione and chlorides did not impact northern PD rates. During an ecosystem-wide experiment conducted in a covered BYL pond, there was neither net MeHg increase in the dark nor loss attributable to PD following re-exposure to sunlight. We propose that high-DOC Arctic thaw ponds are more prone to MeHg PD than nearby oligotrophic lakes, likely through photoproduction of reactive species rather than via thiol complexation. However, at the ecosystem level, these ponds, which are widespread through the Arctic, remain likely sources of MeHg for neighboring systems. PMID:26938195

  18. The nature and fate of natural resins in the geosphere VI. Analysis of fossil resins from Axel Heiberg Island Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, K.B. [Argonne National Lab., IL (United States)]|[Amoco Oil Co., Naperville, IL (United States); LePage, B.A. [Univ. of Alberta, Edmonton (Canada). Dept. of Biological Sciences

    1995-06-01

    Ambers are well known and abundant in terrestrial sediments all over the world; however, due largely to the absence of definite morphological characteristics, the precise botanical origin of most amber samples, are at best, often a matter of speculation. This has severely restricted the usefulness of amber in paleobotanical and paleoecological interpretations. The molecular composition and structural characteristics of fossil resins however, may preserve evidence of their botanical origin, which could be of great value in both geochemical, paleobotanical, and paleoenvironmental studies. The remains of a number of exceptionally well-preserved Taxodiaceae-dominated swamp-forest communities have been identified in the sediments of the middle Eocene (45 million years old) Buchanan Lake Formation of Axel Heiberg Island, Canadian Arctic Archipelago. The amber collected from these ancient in situ forests provides a unique opportunity to characterize these resins chemically and taxonomically. Resinite associated with Metasequoia, Pinus and Pseudolarix has been characterized using Pyrolysis-Gas Chromatography-Mass Spectrometry. This method provides a direct analysis of the molecular structure and composition of the resin. In several cases, both bled resin and cone-resin samples have been characterized. The results of these analyses are presented and discussed. The implications of these results for the botanical origins of other ambers represented in the fossil record (including succinite) will also be discussed.

  19. Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic.

    Science.gov (United States)

    Scheuhammer, Anton; Braune, Birgit; Chan, Hing Man; Frouin, Héloïse; Krey, Anke; Letcher, Robert; Loseto, Lisa; Noël, Marie; Ostertag, Sonja; Ross, Peter; Wayland, Mark

    2015-03-15

    This review summarizes our current state of knowledge regarding the potential biological effects of mercury (Hg) exposure on fish and wildlife in the Canadian Arctic. Although Hg in most freshwater fish from northern Canada was not sufficiently elevated to be of concern, a few lakes in the Northwest Territories and Nunavut contained fish of certain species (e.g. northern pike, Arctic char) whose muscle Hg concentrations exceeded an estimated threshold range (0.5-1.0 μg g(-1) wet weight) within which adverse biological effects begin to occur. Marine fish species generally had substantially lower Hg concentrations than freshwater fish; but the Greenland shark, a long-lived predatory species, had mean muscle Hg concentrations exceeding the threshold range for possible effects on health or reproduction. An examination of recent egg Hg concentrations for marine birds from the Canadian Arctic indicated that mean Hg concentration in ivory gulls from Seymour Island fell within the threshold range associated with adverse effects on reproduction in birds. Mercury concentrations in brain tissue of beluga whales and polar bears were generally lower than levels associated with neurotoxicity in mammals, but were sometimes high enough to cause subtle neurochemical changes that can precede overt neurotoxicity. Harbour seals from western Hudson Bay had elevated mean liver Hg concentrations along with comparatively high muscle Hg concentrations indicating potential health effects from methylmercury (MeHg) exposure on this subpopulation. Because current information is generally insufficient to determine with confidence whether Hg exposure is impacting the health of specific fish or wildlife populations in the Canadian Arctic, biological effects studies should comprise a major focus of future Hg research in the Canadian Arctic. Additionally, studies on cellular interactions between Hg and selenium (Se) are required to better account for potential protective effects of Se on Hg

  20. Evaluation and post-treatment of reanalysis precipitation series over Canadian Arctic

    Science.gov (United States)

    Mailhot, A.; Aubin, P.; Khedhaouiria, D.; Talbot, G.

    2015-12-01

    Assessing the climate of Canadian Arctic region is challenging since few meteorological records are available. Interpolated gridded datasets are also of limited use because network density was historically small and resulting values strongly depend on the interpolation method. Reanalysis therefore represent an interesting alternative. The objective of this study was to analyze the performance of reanalysis to represent the precipitation for Canada and especially for the Canadian Arctic. Three reanalysis were considered: ERA-Interim, MERRA and CFSR. Annual and monthly precipitations series from these reanalysis were compared to corresponding series from record stations (approximately 1 500 stations across Canada with a few hundreds stations in Northern Canada). Reanalysis grid-box closest to a given station was considered for the comparison. Mean Square Errors (MSE), bias, Pearson correlation coefficient (PCC) and ratio of variances between precipitation series from each pair station/reanalysis were estimated. These indicators have been used in order to assess the performance of reanalysis to reproduce the sequence of annual and monthly precipitation series. Results shown that, globally, ERA-Interim led to the smallest PCC, followed by MERRA and CFSR for annual precipitation series. All three reanalysis displayed large biases. A simple post-treatment method was then applied to the reanalysis series. It was first applied at local scale considering each pair of station/reanalysis. Improvement in MSE and PCC values using post-treated series were significant. In order to be able to use the reanalysis at gird-boxes where no station is available, a regional version of this post-treatment was implemented. This regional version consisted in the estimation of optimal mean regional values of post-treated parameters. Assessment of the performance of this regional post-treatment method was made using cross-validation.

  1. Multiproxy paleoecological evidence of Holocene climatic changes on the Boothia Peninsula, Canadian Arctic

    Science.gov (United States)

    Fortin, Marie-Claude; Gajewski, Konrad

    2016-05-01

    A study of chironomid remains in the sediments of Lake JR01 on the Boothia Peninsula in the Central Canadian Arctic provides a high-resolution record of mean July air temperatures for the last 6.9 ka. Diatom and pollen studies have previously been published from this core. Peak Holocene temperatures occurred prior to 5.0 ka, a time when overall aquatic and terrestrial biological production was high. Chironomid-inferred summer air temperatures reached up to 7.5°C during this period. The region of Lake JR01 cooled over the mid- to late-Holocene, with high biological production between 6.1 and 5.4 ka. Biological production decreased again at ∼2 ka and the rate of cooling increased in the past 2 ka, with coolest temperatures occurring between 0.46 and 0.36 ka, coinciding with the Little Ice Age. Although biological production increased in the last 150 yr, the reconstructed temperatures do not indicate a warming during this time. During transitions, either warming or cooling, chironomid production increases, suggesting an ecosystem-level response to climate variability, seen at a number of lakes across the Arctic.

  2. Brown snow: A long-range transport event in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Welch, H.E.; Muir, D.C.G.; Billeck, B.N.; Lockhart, W.L.; Brunskill, G.J.; Kling, H.J. (Freshwater Inst., Winnipeg (Canada)); Olson, M.P. (Atmospheric Environment Service, Downsview, Ontario (Canada)); Lemoine, R.M. (Hardy BBT Ltd., Winnipeg, Manitoba (Canada))

    1991-02-01

    The authors document the occurrence of a long-range transport event that deposited thousands of tons of fine particulates on the District of Keewatin, central Canadian Arctic, {approximately}63 N. Air mass trajectories, clay mineral composition, soot particles, and visible organic remains point to Asian sources for the brown snow material, probably western China. Semivolatile organic pollutants detected in the brown snow included polycyclic aromatic hydrocarbons ({Sigma}PAH), PCB congeners, and DDT-related compounds ({Sigma}DDT), polychlorinated camphenes (PCCs), as well as the herbicide trifuluralin and insecticides methoxychlor, endosulfan, and hexachlorocyclohexane (HCH). {Sigma}PAH, PCB, and PCC concentrations were within the range reported in other studies of Arctic snow but {Sigma}DDT levels were 2-10 times higher than previous reports. High molecular weight PAH may have been associated with soot particles in the brown snow but evidence for Asian sources of the pesticides was not strong because of unknown source signal strengths and possible atmospheric transformations of the compounds. Fluxes of these pollutants were also determined by analyzing sediment cores from two small headwater lakes near the sampling site. The quantities of pollutants deposited in this single event may have comprised a significant fraction (>10%) of total annual input {Sigma}PAH and {Sigma}DDT, as determined from lake sedimentation records.

  3. Measurements of the dissolved inorganic carbon system and associated biogeochemical parameters in the Canadian Arctic, 1974–2009

    Directory of Open Access Journals (Sweden)

    K. E. Giesbrecht

    2013-06-01

    Full Text Available We have assembled and conducted primary quality control on previously publically-unavailable water column measurements of the dissolved inorganic carbon system and associated biogeochemical parameters (oxygen, nutrients, etc. made on 25 cruises in the subarctic and Arctic regions dating from as far back as 1974. The measurements are primarily from the western side of the Canadian Arctic, but also include data ranging from the North Pacific to the Gulf of St. Lawrence. The data were subjected to primary quality control (QC to identify outliers and obvious errors. This dataset incorporates over four thousand individual measurements of total inorganic carbon (TIC, alkalinity, and pH from the Canadian Arctic over a period of more than 30 yr and provides an opportunity to increase our understanding of temporal changes in the inorganic carbon system in northern waters and the Arctic Ocean. The dataset is available for download on the CDIAC website: http://cdiac.ornl.gov/ftp/oceans/IOS_Arctic_Database/ (doi:10.3334/CDIAC/OTG.IOS_ARCT_CARBN.

  4. The role of seasonal migration in the near-total loss of caribou on south-central Canadian Arctic Islands

    Directory of Open Access Journals (Sweden)

    Frank L. Miller

    2007-04-01

    estimated 5097 1+ yr-old caribou in 1980 to fewer than 100 1+ yr-old caribou in 1995 (Gunn & Decker, 1984; Miller, 1997; Gunn & Dragon, 1998; Gunn et al., 2006. This loss of caribou on those islands amounts to a near-total loss of a genetically distinctive group of Arctic-island caribou (e.g., Zittlau, 2004. In contrast, the estimated number of caribou in the geographic population on Boothia Peninsula appeared to increase by 1.4-fold from 4831 to 6658 1+ yr-old caribou between 1985 and 1995, although annual harvesting pressure was heavy. It was biologically impossible for the Boothia Peninsula geographic population at its 1985 estimated size to have persisted until 1995, let alone to have increased, under the estimated average annual harvest regime of 1100 1+ yr-old caribou • yr-1. There is no evidence that the Boothia Peninsula population was underestimated in 1985. It would have required a population in 1985 at least twice as great as the calculated estimate to sustain the estimated annual harvest between 1985 and 1995. An underestimate of such magnitude is too great to be probable. In our examination of the survey results, we could find no reason to question that the calculated population estimates were not reasonable approximations. The fixed-wing aerial surveys in 1980 (Gunn & Decker, 1984, 1985 (Gunn & Ashevak, 1990, and 1995 (Gunn & Dragon, 1998 were highly comparable, well designed and executed, using standard procedures for a fixed-width, strip-transect, systematic aerial survey of caribou. One of the two observers was the same experienced survey biologist in all 3 years, the second observer in 1980 was an experienced survey biologist and in 1985 and 1995 was an experienced Inuit hunter familiar with the area, and the pilot was the same on all surveys and had flown many systematic surveys of caribou on the Canadian Arctic Archipelago and mainland Canada. Helicopter searches of known caribou ranges on Prince of Wales, Russell, and Somerset islands that were

  5. Natural Radioactivity Accumulated in the Arctic from Long-range Atmospheric Transport - Observations in Canadian Monitoring Stations

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing; Zhang, Weihua [Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A 1C1 (Canada)

    2014-07-01

    In the environment, the main sources of naturally occurring radionuclides come from radionuclides in the uranium decay series. Activity concentrations of uranium decay series radionuclides may vary considerably from place to place depending on the geological characteristics at the location. Their releases to the atmosphere are mainly through radon ({sup 222}Rn), a radioactive noble gas occurring naturally as an indirect decay product of uranium in soils and rocks. Due to the abundance of uranium, radon continuously emanates from continental land masses. With radon as the main source of naturally occurring radioactivity in the environment, one would think that the Arctic should be an area of low background radiation, because a considerable area of the Arctic is covered by glaciers and permafrost, and radon emanation rate has been reported to be negligible from those glacier and permafrost areas. However, available data have shown the opposite. The elevated level of naturally occurring radioactivity in the Arctic is due to natural sources outside of the Arctic, mainly through long-range atmospheric transport of radon and radon progeny. In some cases, natural radioactivity can accumulate to relatively high levels and become a health concern or a limiting factor of country food consumption. By definition, contaminants are undesirable substances which can cause harm to the environment, the biota, and humans. We can call these naturally accumulating radiological burdens to the Arctic 'natural contaminants' to distinguish them from the traditional meaning of contamination, the 'artificial contaminants' which are attributable to industrial or man-made sources. This paper reviews information available in the literature, analyses long-term atmospheric monitoring data in the Canadian high Arctic, sub-Arctic and mid-latitude sites, and provides discussion on research needed to address questions, such as how heavily the Arctic has been impacted by the

  6. Natural Radioactivity Accumulated in the Arctic from Long-range Atmospheric Transport - Observations in Canadian Monitoring Stations

    International Nuclear Information System (INIS)

    In the environment, the main sources of naturally occurring radionuclides come from radionuclides in the uranium decay series. Activity concentrations of uranium decay series radionuclides may vary considerably from place to place depending on the geological characteristics at the location. Their releases to the atmosphere are mainly through radon (222Rn), a radioactive noble gas occurring naturally as an indirect decay product of uranium in soils and rocks. Due to the abundance of uranium, radon continuously emanates from continental land masses. With radon as the main source of naturally occurring radioactivity in the environment, one would think that the Arctic should be an area of low background radiation, because a considerable area of the Arctic is covered by glaciers and permafrost, and radon emanation rate has been reported to be negligible from those glacier and permafrost areas. However, available data have shown the opposite. The elevated level of naturally occurring radioactivity in the Arctic is due to natural sources outside of the Arctic, mainly through long-range atmospheric transport of radon and radon progeny. In some cases, natural radioactivity can accumulate to relatively high levels and become a health concern or a limiting factor of country food consumption. By definition, contaminants are undesirable substances which can cause harm to the environment, the biota, and humans. We can call these naturally accumulating radiological burdens to the Arctic 'natural contaminants' to distinguish them from the traditional meaning of contamination, the 'artificial contaminants' which are attributable to industrial or man-made sources. This paper reviews information available in the literature, analyses long-term atmospheric monitoring data in the Canadian high Arctic, sub-Arctic and mid-latitude sites, and provides discussion on research needed to address questions, such as how heavily the Arctic has been impacted by the accumulation of naturally

  7. Effect of Terrain Characteristics on Soil Organic Carbon and Total Nitrogen Stocks in Soils of Herschel Island, Western Canadian Arctic

    OpenAIRE

    Obu, Jaroslav; Lantuit, Hugues; Myers-Smith, Isla; Heim, Birgit; Wolter, Juliane; Fritz, Michael

    2015-01-01

    Permafrost landscapes experience different disturbances and store large amounts of organic matter, which may become a source of greenhouse gases upon permafrost degradation. We analysed the influence of terrain and geomorphic disturbances (e.g. soil creep, active-layer detachment, gullying, thaw slumping, accumulation of fluvial deposits) on soil organic carbon (SOC) and total nitrogen (TN) storage using 11 permafrost cores from Herschel Island, western Canadian Arctic. Our results indicate a...

  8. Summer foraging behaviour of shallow-diving seabirds and distribution of their prey, Arctic cod (Boreogadus saida, in the Canadian Arctic

    Directory of Open Access Journals (Sweden)

    Jordan K. Matley

    2012-09-01

    Full Text Available Productive areas in the Canadian Arctic seasonally provide top predators with accessible and often predictable sources of energy. Arctic cod (Boreogadus saida aggregate in shallow bays during the summer and are exploited by seabirds and marine mammals. Information concerning how prey is presented to predatory seabirds, and the cues seabirds use to optimize foraging potential, is limited. Hydroacoustic surveys were completed in Allen Bay, Nunavut, to determine the presence, density, abundance, and depth of Arctic cod schools in relation to shallow-diving seabirds. Schools were also documented using standardized protocols to examine the influence of environmental variables, such as wind, ice, tidal states and seabird behaviour. The presence of schools was a significant predictor of the distribution of northern fulmars (Fulmarus glacialis but not black-legged kittiwakes (Rissa tridactyla. Glaucous gulls (Larus hyperboreus associated with northern fulmars are likely optimizing chances of stealing Arctic cod. The density, size and depth of schools did not significantly affect the distribution of the seabirds. We speculate that Arctic cod from demersal schools separate to feed at the surface in satellite schools (groups of dispersed fish, thus reducing competition but increasing the risk of predation.

  9. Resource utilisation by deep-sea megabenthos in the Canadian High Arctic (Baffin Bay and Parry Channel)

    Science.gov (United States)

    Bourgeois, Solveig; Witte, Ursula; Harrison, Ailish M.; Makela, Anni; Kazanidis, Georgios; Archambault, Philippe

    2016-04-01

    Ongoing climate change in the Arctic is causing drastic alteration of the Arctic marine ecosystem functioning, such as shifts in patterns of primary production, and modifying the present tight pelagic-benthic coupling. Subsequently benthic communities, which rely upon organic matter produced in the top layers of the Ocean, will also be affected by these changes. The benthic megafaunal communities play a significant role in ecological processes and ecosystem functioning (i.e. organic matter recycling, bioturbation, food source for the higher trophic levels…). Yet, information is scarce regarding the main food sources for dominant benthic organisms, and therefore the impact of the ongoing changes is difficult to assess. The goal of this study is to investigate the preferential feeding of different carbon sources by megabenthic organisms in the Canadian High Arctic and to identify environmental drivers which explain the observed trends. In summer 2013, benthic megafauna was collected at 9 stations spread along latitudinal (58 to 81°N) and longitudinal (62 to 114°W) transects in the Baffin Bay and Parry Channel, respectively. Carbon and nitrogen bulk stable isotope analyses (δ13C and δ15N) were performed on several species divided into groups according to their feeding type. This study highlights distinct trends in δ13C values of benthic organisms suggesting the importance of both phytoplankton and ice algae as carbon sources for megafauna in the Canadian High Arctic. The importance of physical and biological parameters as drivers of food web structure will be furthermore discussed.

  10. Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2

    Science.gov (United States)

    Chylek, P.; Li, J.; Dubey, M. K.; Wang, M.; Lesins, G.

    2011-08-01

    We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2). The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and the intervening 1940-1970 period of substantial cooling. The addition of the land-vegetation model and the terrestrial and oceanic interactive carbon cycle to the coupled atmosphere-ocean model improves the agreement with observations from 1900-1970, however, it increases the overestimate of the post 1970 warming. In contrast the older generation coupled atmosphere-ocean general circulation models Canadian CanCM3 and NCAR/LANL CCSM3, used in the IPCC 2007 climate change assessment report, overestimate the rate of the 20th century Arctic warming by factor of two to three and they are unable to reproduce the observed 20th century Arctic climate variability.

  11. Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2

    Directory of Open Access Journals (Sweden)

    P. Chylek

    2011-08-01

    Full Text Available We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2. The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and the intervening 1940–1970 period of substantial cooling. The addition of the land-vegetation model and the terrestrial and oceanic interactive carbon cycle to the coupled atmosphere-ocean model improves the agreement with observations from 1900–1970, however, it increases the overestimate of the post 1970 warming. In contrast the older generation coupled atmosphere-ocean general circulation models Canadian CanCM3 and NCAR/LANL CCSM3, used in the IPCC 2007 climate change assessment report, overestimate the rate of the 20th century Arctic warming by factor of two to three and they are unable to reproduce the observed 20th century Arctic climate variability.

  12. Characterizing aerosol transport into the Canadian High Arctic using aerosol mass spectrometry and Lagrangian modelling

    Directory of Open Access Journals (Sweden)

    T. Kuhn

    2010-05-01

    Full Text Available We report the analysis of measurements made using an aerosol mass spectrometer (AMS; Aerodyne Research Inc. that was installed in the Polar Environment Atmospheric Research Laboratory (PEARL in summer 2006. PEARL is located in the Canadian high Arctic at 610 m above sea level on Ellesmere Island (80° N 86° W. PEARL is unique for its remote location in the Arctic and because most of the time it is situated within the free troposphere. It is therefore well suited as a receptor site to study the long range tropospheric transport of pollutants into the Arctic. Some information about the successful year-round operation of an AMS at a high Arctic site such as PEARL will be reported here, together with design considerations for reliable sampling under harsh low-temperature conditions. Computational fluid dynamics calculations were made to ensure that sample integrity was maintained while sampling air at temperatures that average −40 °C in the winter and can be as low as −55 °C. Selected AMS measurements of aerosol mass concentration, size, and chemical composition recorded during the months of August, September and October 2006 will be reported. During this period, sulfate was at most times the predominant aerosol component with on average 0.115 μg m−3 (detection limit 0.003 μg m−3. The second most abundant component was undifferentiated organic aerosol, with on average 0.11 μg m−3 detection limit (0.04 μg m−3. The nitrate component, which averaged 0.007 μg m−3, was above its detection limit (0.002 μg m−3, whereas the ammonium ion had an apparent average concentration of 0.02 μg m−3, which was approximately equal to its detection limit. A few episodes having increased mass concentrations and lasting from several hours to several days are apparent in the data. These were investigated further using a statistical analysis to determine their common

  13. Irradiation as an alternative for disinfection of domestic waste in the Canadian Arctic

    International Nuclear Information System (INIS)

    This study evaluated the technical and economic feasibility of various methods for disinfecting wastewater in the Canadian Arctic with specific reference to gamma radiation. More conventional disinfection practices, such as chlorination, chlorination-dechlorination, and ozonation were compared to gamma radiation along with ultraviolet irradiation and lime disinfection. The quality of lagoon effluent, highly diluted (weak) sewage, holding tank wastes and honey-bag wastes, which are the typical waste types found in northern communities, was established from data available in the literature. Further literature reviews were undertaken to establish a data base for design and effectiveness of disinfection systems operated in cold climates. Capital and operating costs for all technically feasible disinfection process alternates were estimated based on historical cost data adjusted to 1977 for the construction and instalation of similar systems in the north. The costs of equipment, chemicals, fuel and electrical power were obtained from suppliers. The environmental impact of each of the disinfection processes was reviewed with emphasis on gamma irradiation. Safety and health aspects were also considered. The study concluded that gamma irradiation was capable of providing safe, reliable disinfection for concentrated honey-bag and holding wastes. Pilot-scale testing was recommended prior to construction of full-scale disinfection facilities. For lagoon effluents and weak sewage, gamma irradiation was not cost competitive with other alternates; rather chlorination-dechlorination was found to be the most cost-effective and environmentally acceptable alternative

  14. Reconstruction of Centennial and Millennial-scale Climate and Environmental Variability during the Holocene in the Central Canadian Arctic

    Science.gov (United States)

    Rolland, N.; Porinchu, D.; MacDonald, G.; Moser, K.

    2007-12-01

    The Arctic and sub-Arctic regions are experiencing dramatic changes in surface temperature, sea-ice extent, glacial melt, river discharge, soil carbon storage and snow cover. According to the IPCC high latitude regions are expected to warm between 4°C and 7°C over the next 100 years. The magnitude of warming and the rate at which it occurs will dwarf any previous warming episodes experienced by latitude regions over the last 11,000 years. It is critical that we improve our understanding of how the Arctic and sub-Arctic regions responded to past periods of warming, especially in light of the changes these regions will be experiencing over the next 100 years. One of the lines of evidence increasingly utilized in multi-proxy paleolimnological research is the Chironomidae (Insecta: Diptera). Also known as non-biting midge flies, chironomids are ubiquitous, frequently the most abundant insects found in freshwater ecosystems and very sensitive to environmental conditions. This research uses Chironomidae to quantitatively characterize climate and environmental conditions of the continental interior of Arctic Canada during the Holocene. Spanning four major vegetation zones (boreal forest, forest-tundra, birch tundra and herb tundra), the surface samples of 80 lakes recovered from the central Canadian Arctic were used to assess the relationship of 22 environmental variables with the chironomid distribution. Redundancy analysis (RDA) identified four variables, total Kjeldahl nitrogen (TKN), pH, summer surface water temperature (SSWT) and depth, which best explain the variance in the distribution of chironomids within these ecoregions. In order to provide new quantitative estimates of SSWT, a 1-component weighted average partial least square (WA-PLS) model was developed (r2jack = 0.76, RMSEP = 1.42°C) and applied downcore in two low arctic continental Nunavut lakes located approximately 50 km and 200 km north of modern treeline. This robust midge-inferred temperature

  15. Spatial trends and factors affecting variation of organochlorine contaminants levels in Canadian Arctic beluga (Delphinapterus leucas).

    Science.gov (United States)

    Stern, G A; Macdonald, C R; Armstrong, D; Dunn, B; Fuchs, C; Harwood, L; Muir, D C G; Rosenberg, B

    2005-12-01

    Organochlorine pesticides and PCBs were analysed in blubber from beluga (Delphinapterus leucas), or white whales, collected at 15 sites in the Canadian Arctic between 1993 and 2001. The objective of the study was to define and interpret the spatial trends of major organic contaminants in northern beluga in terms of sources and transport pathways, and the biological factors influencing accumulation. When compared on a lipid weight basis, the concentrations of beta-HCH, cis-CHL and SigmaCHL, cis-nonachlor, heptachlor epoxide and p,p'-DDT were significantly higher in males than females at all five sites in the eastern Arctic where the two sexes were harvested. The differences were attributed to losses from the females during fetal development and lactation as reported in previous studies. Major compounds increased with age in males at most sites, however the lack of a significant increase with age at some sites was in part due to high organochlorine concentrations in young year classes (2-5 years), particularly at eastern sites such as Iqaluit and Pangnirtung. Lower concentrations of SigmaHCH and SigmaDDT compounds in young males in 2001 relative to 1995 at Hendrickson Island could be due to declining levels in the environment, changes in the diet, or differences in organochlorine loads transferred from the female after birth. Age-corrected least square mean concentrations in males showed significantly higher levels of many compounds, such as p,p'-DDE and SigmaCHB, at south Baffin Island sites than those in the west. Two notable exceptions were HCBz and beta-HCH which were higher in the west. Methoxyclor was detected in males at Sanikiluaq (58 ng g-1) and in both sexes at Kimmirut, but at no other sites. Principal component analysis grouped the 16 sites into five major groupings based on the similarity of normalised organochlorine pesticide and PCB levels. Sites from the western Arctic were grouped by higher proportions of HCBz, beta-HCH and gamma-HCH and higher

  16. Ten-year trends of atmospheric mercury in the high Arctic compared to Canadian sub-Arctic and mid-latitude sites

    Directory of Open Access Journals (Sweden)

    A. S. Cole

    2013-02-01

    Full Text Available Global emissions of mercury continue to change at the same time as the Arctic is experiencing ongoing climatic changes. Continuous monitoring of atmospheric mercury provides important information about long-term trends in the balance between transport, chemistry, and deposition of this pollutant in the Arctic atmosphere. Ten-year records of total gaseous mercury (TGM from 2000 to 2009 were analyzed from two high Arctic sites at Alert (Nunavut, Canada and Zeppelin Station (Svalbard, Norway; one sub-Arctic site at Kuujjuarapik (Nunavik, Québec, Canada; and three temperate Canadian sites at St. Anicet (Québec, Kejimkujik (Nova Scotia and Egbert (Ontario. Five of the six sites examined showed a decreasing trend over this time period. Overall trend estimates at high latitude sites were: −0.9% yr−1 (95% confidence limits: −1.4, 0 at Alert and no trend (−0.5, +0.7 at Zeppelin Station. Faster decreases were observed at the remainder of the sites: −2.1% yr−1 (−3.1, −1.1 at Kuujjuarapik, −1.9% yr−1 (−2.1, −1.8 at St. Anicet, −1.6% yr−1 (−2.4, −1.0 at Kejimkujik and −2.2% yr−1 (−2.8, −1.7 at Egbert. Trends at the sub-Arctic and mid-latitude sites agree with reported decreases in background TGM concentration since 1996 at Mace Head, Ireland, and Cape Point, South Africa, but conflict with estimates showing an increase in global anthropogenic emissions over a similar period. Trends in TGM at the two high Arctic sites were not only less negative (or neutral overall but much more variable by season. Possible reasons for differences in seasonal and overall trends at the Arctic sites compared to those at lower latitudes are discussed, as well as implications for the Arctic mercury cycle. The first calculations of multi-year trends in reactive gaseous mercury (RGM and total particulate mercury (TPM at Alert were also performed, indicating increases from 2002 to 2009

  17. Radiocesium in Canadian Arctic Beluga and Caribou Before and After the Fukushima Accident of 2011

    Energy Technology Data Exchange (ETDEWEB)

    Stocki, Trevor J.; Pellerin, Eric; Bergman, Lauren; Mercier, Jean-Francois; Genovesi, Linda; Cooke, Michael; Todd, Bonnie; Sandles, Diane; Whyte, Jeff [Radiation Protection Bureau, Health Canada, AL6302D, 775 Brookfield Road, Ottawa, Ontario, Canada, K1A 0K9 (Canada); Gamberg, Mary [Gamberg Consulting, Whitehorse, Yukon (Canada); Loseto, Lisa [Fisheries and Oceans Canada, Winnipeg, Manitoba (Canada); Wang, X. [Environment Canada, Burlington Ontario (Canada)

    2014-07-01

    Following the Fukushima Daiichi nuclear accident in March 2011, northern Canadians expressed concerns about the levels of radioactive contaminants in important traditional foods. Therefore, a study has been conducted to measure the levels of radionuclides in Arctic caribou and beluga whales. The main radionuclide of concern is cesium-137, which has a half-life of 30 years and is chemically similar to potassium, thereby easily accumulating in plants and animals. Cesium-137 was released into the atmosphere during nuclear weapons tests in the 1950's-60's and during nuclear accidents, such as Chernobyl. Previous studies have been made on the cesium-137 levels in Canadian caribou herds from 1958 to 2000, allowing researchers to determine the amount of cesium-137 in caribou specifically attributable to atmospheric weapons testing and the Chernobyl accident. Samples of lichens, mushrooms, caribou and beluga whales taken before and after the Fukushima accident were freeze dried, homogenized, and measured using gamma ray spectroscopy to identify the radionuclides present and determine the radioactivity concentration in the samples. To determine the efficiency of the detectors for the different sized samples, physical calibration standards were used and virtual simulations were also performed. A comparison of the caribou samples from before and after the accident has indicated no increase in radioactivity as a result of the Fukushima accident. Results are consistent with pre-Fukushima levels for these caribou. No Cs-137 was found in the pre-Fukushima beluga whale samples, even if all the measurements were combined into one spectrum. In the individual post-Fukushima beluga whale samples, Cs-137 was also not found. However, when the post-Fukushima beluga whale measurements were combined, an insignificant amount of radioactive Cs-137 was found. The amount of this Cs-137 was about 200 times smaller than the natural radioactive potassium in the samples. Most likely the

  18. Radiocesium in Canadian Arctic Beluga and Caribou Before and After the Fukushima Accident of 2011

    International Nuclear Information System (INIS)

    Following the Fukushima Daiichi nuclear accident in March 2011, northern Canadians expressed concerns about the levels of radioactive contaminants in important traditional foods. Therefore, a study has been conducted to measure the levels of radionuclides in Arctic caribou and beluga whales. The main radionuclide of concern is cesium-137, which has a half-life of 30 years and is chemically similar to potassium, thereby easily accumulating in plants and animals. Cesium-137 was released into the atmosphere during nuclear weapons tests in the 1950's-60's and during nuclear accidents, such as Chernobyl. Previous studies have been made on the cesium-137 levels in Canadian caribou herds from 1958 to 2000, allowing researchers to determine the amount of cesium-137 in caribou specifically attributable to atmospheric weapons testing and the Chernobyl accident. Samples of lichens, mushrooms, caribou and beluga whales taken before and after the Fukushima accident were freeze dried, homogenized, and measured using gamma ray spectroscopy to identify the radionuclides present and determine the radioactivity concentration in the samples. To determine the efficiency of the detectors for the different sized samples, physical calibration standards were used and virtual simulations were also performed. A comparison of the caribou samples from before and after the accident has indicated no increase in radioactivity as a result of the Fukushima accident. Results are consistent with pre-Fukushima levels for these caribou. No Cs-137 was found in the pre-Fukushima beluga whale samples, even if all the measurements were combined into one spectrum. In the individual post-Fukushima beluga whale samples, Cs-137 was also not found. However, when the post-Fukushima beluga whale measurements were combined, an insignificant amount of radioactive Cs-137 was found. The amount of this Cs-137 was about 200 times smaller than the natural radioactive potassium in the samples. Most likely the Cs-137

  19. Cloud identification in the Canadian High Arctic using the UV-visible colour index

    Science.gov (United States)

    Zhao, Xiaoyi; Adams, Cristen; Strong, Kimberly; Duck, Thomas; Perro, Chris; Hudak, David; Rodriguez, Peter

    2014-05-01

    In UV-visible spectroscopy, Rayleigh and Mie scattering contribute to the broadband extinction seen in spectra of scattered sunlight. The relative intensity of these two components of scattering is highly dependent on the cloud condition of the sky. The colour index, defined as the ratio of light intensities at different wavelengths, typically 350 nm and 550 nm, provides a means of determining the cloud conditions. A UV-visible triple-grating spectrometer, the UT-GBS (University of Toronto Ground-Based Spectrometer), was installed at the Polar Environment Atmospheric Research Laboratory (PEARL), at Eureka in the Canadian High Arctic (86.4°W, 80.1°N) in 1999. Since then, the instrument has made daily measurements during spring from 1999-2009, and year-round, with the exception of polar night, from 2010-2013. The UT-GBS measures vertical column densities of ozone, NO2, and BrO, as well as slant column densities of enhanced OClO, by using the Differential Optical Absorption Spectroscopy (DOAS) technique. We use the colour index data from the UT-GBS to distinguish polar stratospheric clouds and tropospheric clouds. The UV-visible measurements are supplemented by vertically resolved lidar and radar cloud data products. The CANDAC (Canadian Network for the Detection of Atmospheric Change) Rayleigh-Mie-Raman Lidar (CRL) and the Millimetre Cloud Radar (MMCR) are located at the Zero Altitude PEARL Auxiliary Laboratory (0PAL), which is about 15 km away from PEARL. The CRL uses ultra-short pulses of light from two lasers, operating at ultraviolet (355 nm) and visible (532 nm) wavelengths. The CRL measures the vertical distribution of aerosols, temperature, and water vapour in the troposphere and lower stratosphere. The zenith-pointing MMCR measures equivalent radar reflectivity, Doppler velocity, spectral width, and Doppler spectra, from which information about cloud heights, thicknesses, internal structure and vertical motions can be determined. Polar stratospheric cloud

  20. Acceleration of thaw slump activity in glaciated landscapes of the Western Canadian Arctic

    Science.gov (United States)

    Segal, Rebecca A.; Lantz, Trevor C.; Kokelj, Steven V.

    2016-03-01

    Climate change is increasing the frequency and intensity of thermokarst, but the influences of regional climate and physiography remain poorly understood. Retrogressive thaw slumping is one of the most dynamic forms of thermokarst and affects many areas of glaciated terrain across northwestern Canada. In this study, we used airphotos and satellite imagery to investigate the influence of climate and landscape factors on thaw slump dynamics. We assessed slump size, density, and growth rates in four regions of ice-rich terrain with contrasting climate and physiographic conditions: the Jesse Moraine, the Tuktoyaktuk Coastlands, the Bluenose Moraine, and the Peel Plateau. Observed increases in: (1) the area impacted by slumps (+2 to +407%), (2) average slump sizes (+0.31 to +1.82 ha), and (3) slump growth rates (+169 to +465 m2 yr-1) showed that thermokarst activity is rapidly accelerating in ice-rich morainal landscapes in the western Canadian Arctic, where slumping has become a dominant driver of geomorphic change. Differences in slump characteristics among regions indicate that slump development is strongly influenced by topography, ground ice conditions, and Quaternary history. Observed increases in slump activity occurred in conjunction with increases in air temperature and precipitation, but variation in slump activity among the four regions suggests that increased precipitation has been an important driver of change. Our observation that the most rapid intensification of slump activity occurred in the coldest environment (the Jesse Moraine on Banks Island) indicates that ice-cored landscapes in cold permafrost environments are highly vulnerable to climate change.

  1. Surveys of belugas and narwhals in the Canadian High Arctic in 1996

    Directory of Open Access Journals (Sweden)

    Stuart Innes

    2014-01-01

    Full Text Available The summer range of belugas (Delphinapterus leucas and narwhals (Monodon monoceros in Prince Regent Inlet, Barrow Strait and Peel Sound in the Canadian High Arctic was surveyed from 31 July to 3 August 1996 with a visual aerial survey of offshore areas and photographic aerial surveys of concentration areas. The visual survey estimate based on the number of belugas visible to the observers using systematic line transect methods was 10,347 (cv = 0.28. This included corrections for whales that were missed by the observers, observations without distance measurements and an estimate of 1,949 (cv=0.22 belugas from a photographic survey in southern Peel Sound. Using data from belugas tagged with satellite-linked time-depth recorders, the estimate was adjusted for individuals that were diving during the survey which resulted in an estimate of 18,930 belugas (cv = 0.28. Finally, counts of belugas in estuaries, corrected for estuarine surface time, were added to provide a complete estimate of 21,213 belugas (95% CI 10,985 to 32,619. The estimated number of narwhals corrected for sightings that were missed by observers was 16,364 (cv = 0.24. Adjusting this for sightings without distance information and correcting for whales that were submerged produced an estimate of 45,358 narwhals (95% CI 23,397 to 87,932.

  2. Fast carnivores and slow herbivores: differential foraging strategies among grizzly bears in the Canadian Arctic.

    Science.gov (United States)

    Edwards, Mark A; Derocher, Andrew E; Hobson, Keith A; Branigan, Marsha; Nagy, John A

    2011-04-01

    Categorizing animal populations by diet can mask important intrapopulation variation, which is crucial to understanding a species' trophic niche width. To test hypotheses related to intrapopulation variation in foraging or the presence of diet specialization, we conducted stable isotope analysis (δ(13)C, δ(15)N) on hair and claw samples from 51 grizzly bears (Ursus arctos) collected from 2003 to 2006 in the Mackenzie Delta region of the Canadian Arctic. We examined within-population differences in the foraging patterns of males and females and the relationship between trophic position (derived from δ(15)N measurements) and individual movement. The range of δ(15)N values in hair and claw (2.0-11.0‰) suggested a wide niche width and cluster analyses indicated the presence of three foraging groups within the population, ranging from near-complete herbivory to near-complete carnivory. We found no linear relationship between home range size and trophic position when the data were continuous or when grouped by foraging behavior. However, the movement rate of females increased linearly with trophic position. We used multisource dual-isotope mixing models to determine the relative contributions of seven prey sources within each foraging group for both males and females. The mean bear dietary endpoint across all foraging groups for each sex fell toward the center of the mixing polygon, which suggested relatively well-mixed diets. The primary dietary difference across foraging groups was the proportional contribution of herbaceous foods, which decreased for both males and females from 42-76 to 0-27% and 62-81 to 0-44%, respectively. Grizzlies of the Mackenzie Delta live in extremely harsh conditions and identifying within-population diet specialization has improved our understanding of varying habitat requirements within the population. PMID:21153738

  3. Temporal trends of mercury in eggs of five sympatrically breeding seabird species in the Canadian Arctic.

    Science.gov (United States)

    Braune, Birgit M; Gaston, Anthony J; Mallory, Mark L

    2016-07-01

    We compared temporal trends of total mercury (Hg) in eggs of five seabird species breeding at Prince Leopold Island in the Canadian high Arctic. As changes in trophic position over time have the potential to influence contaminant temporal trends, Hg concentrations were adjusted for trophic position (measured as δ(15)N). Adjusted Hg concentrations in eggs of thick-billed murres (Uria lomvia) and northern fulmars (Fulmarus glacialis) increased from 1975 to the 1990s, followed by a plateauing of levels from the 1990s to 2014. Trends of adjusted Hg concentrations in eggs of murres, fulmars, black guillemots (Cepphus grylle) and black-legged kittiwakes (Rissa tridactyla) had negative slopes between 1993 and 2013. Adjusted Hg concentrations in glaucous gull (Larus hyperboreus) eggs decreased by 50% from 1993 to 2003 before starting to increase again. Glaucous gull eggs had the highest Hg concentrations followed by black guillemot eggs, and black-legged kittiwake eggs had the lowest concentrations consistently in the five years compared between 1993 and 2013. Based on published toxicological thresholds for Hg in eggs, there is little concern for adverse reproductive effects due to Hg exposure in these birds, although the levels in glaucous gull eggs warrant future scrutiny given the increase in Hg concentrations observed in recent years. There is evidence that the Hg trends observed reflect changing anthropogenic Hg emissions. It remains unclear, however, to what extent exposure to Hg on the overwintering grounds influences the Hg trends observed in the seabird eggs at Prince Leopold Island. Future research should focus on determining the extent to which Hg exposure on the breeding grounds versus the overwintering areas contribute to the trends observed in the eggs. PMID:27074200

  4. Modern to millennium-old greenhouse gases emitted from freshwater ecosystems of the eastern Canadian Arctic

    Science.gov (United States)

    Bouchard, F.; Laurion, I.; Preskienis, V.; Fortier, D.; Xu, X.; Whiticar, M. J.

    2015-07-01

    Ponds and lakes are widespread across the rapidly changing permafrost environments. Aquatic systems play an important role in global biogeochemical cycles, especially in greenhouse gas (GHG) exchanges between terrestrial systems and the atmosphere. The source, speciation and emission of carbon released from permafrost landscapes are strongly influenced by local specific conditions rather than general environmental setting. This study reports on GHG ages and emission rates from aquatic systems on Bylot Island in the eastern Canadian Arctic. Dissolved and ebullition gas samples were collected during the summer season from different types of water bodies located in a highly dynamic periglacial valley: polygonal ponds, collapsed ice-wedge trough ponds, and larger lakes overlying unfrozen soils (talik). The results showed strikingly different ages and fluxes depending on aquatic system types. Polygonal ponds were net sinks of dissolved CO2, but variable sources of dissolved CH4. They presented the highest ebullition fluxes, one or two orders of magnitude higher than from other ponds and lakes. Trough ponds appeared as substantial GHG sources, especially when their edges were actively eroding. Both types of ponds produced modern to hundreds of years old (2000 yr BP) derived from freshly eroded peat. Lakes had small dissolved and ebullition fluxes, however they released much older GHG, including millennium-old CH4 (up to 3500 yr BP) sampled from lake central areas. Acetoclastic methanogenesis dominated at all study sites and there was minimal, if any, methane oxidation in gas emitted through ebullition. These findings provide new insights on the variable role of permafrost aquatic systems as a positive feedback mechanism on climate.

  5. Persistent organic pollutant and mercury concentrations in eggs of ground-nesting marine birds in the Canadian high Arctic.

    Science.gov (United States)

    Peck, Liam E; Gilchrist, H Grant; Mallory, Conor D; Braune, Birgit M; Mallory, Mark L

    2016-06-15

    We collected eggs of eight marine bird species from several colony sites in the Canadian high Arctic located at approximately 76°N and analyzed them for concentrations of legacy persistent organic pollutants (POPs) and mercury. We provide the first report on concentrations of POPs in eggs of three Arctic species (Thayer's gull Larus thayeri, Sabine's gull Xema sabini, Ross's Gull Rhodostethia rosea), and we found significant differences in each of the POP profiles among the five species with sufficient data for statistical comparisons (Thayer's gull, black guillemot Cepphus grylle, Sabine's gull, Arctic tern Sterna paradisaea and common eider Somateria mollissima borealis). The Ross's Gull had unexpectedly high POP concentrations relative to the other species examined, although this was based on a single egg, while glaucous gull Larus hyperboreus eggs from our sampling location had very low POPs. Sabine's gulls had the lowest Hg of the eggs studied, consistent with their low trophic position, but concentrations of their legacy POPs were higher than expected. We also noted that total hexachlorocyclohexanes were higher than reported elsewhere in the circumpolar Arctic in three species. PMID:26971212

  6. Assessing determinants of maternal blood concentrations for persistent organic pollutants and metals in the eastern and western Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Curren, Meredith S., E-mail: meredith.curren@hc-sc.gc.ca [Chemicals Surveillance Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Avenue West, Ottawa, Ontario (Canada); Liang, Chun Lei, E-mail: chun.lei.liang@hc-sc.gc.ca [Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Columbine Driveway, Tunney' s Pasture, Ottawa, Ontario (Canada); Davis, Karelyn, E-mail: karelyn.davis@hc-sc.gc.ca [Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Columbine Driveway, Tunney' s Pasture, Ottawa, Ontario (Canada); Kandola, Kami, E-mail: Kami_Kandola@gov.nt.ca [Government of the Northwest Territories, Yellowknife, Northwest Territories (Canada); Brewster, Janet, E-mail: jbrewster@gov.nu.ca [Government of Nunavut, Iqaluit, Nunavut (Canada); Potyrala, Mary, E-mail: mary_potyrala@yahoo.ca [Government of Nunavut, Iqaluit, Nunavut (Canada); Chan, Hing Man, E-mail: laurie.chan@uottawa.ca [Center for Advanced Research in Environmental Genomics, University of Ottawa, 20 Marie-Curie, Ottawa, Ontario (Canada)

    2015-09-15

    Aboriginal peoples in the Canadian Arctic are exposed to persistent organic pollutants (POPs) and metals mainly through their consumption of a traditional diet of wildlife items. Recent studies indicate that many human chemical levels have decreased in the north, likely due to a combination of reduced global chemical emissions, dietary shifts, and risk mitigation efforts by local health authorities. Body burdens for chemicals in mothers can be further offset by breastfeeding, parity, and other maternal characteristics. We have assessed the impact of several dietary and maternal covariates following a decade of awareness of the contaminant issue in northern Canada, by performing multiple stepwise linear regression analyses from blood concentrations and demographic variables for 176 mothers recruited from Nunavut and the Northwest Territories during the period 2005–2007. A significant aboriginal group effect was observed for the modeled chemicals, except for lead and cadmium, after adjusting for covariates. Further, blood concentrations for POPs and metals were significantly associated with at least one covariate of older age, fewer months spent breastfeeding, more frequent eating of traditional foods, or smoking during pregnancy. Cadmium had the highest explained variance (72.5%) from just two significant covariates (current smoking status and parity). Although Inuit participants from the Northwest Territories consumed more traditional foods in general, Inuit participants from coastal communities in Nunavut continued to demonstrate higher adjusted blood concentrations for POPs and metals examined here. While this is due in part to a higher prevalence of marine mammals in the eastern Arctic diet, it is possible that other aboriginal group effects unrelated to diet may also contribute to elevated chemical body burdens in Canadian Arctic populations. - Highlights: • In 2005–07, younger age was related to lower levels of chemicals in northern Canada. • Eastern

  7. Assessing determinants of maternal blood concentrations for persistent organic pollutants and metals in the eastern and western Canadian Arctic

    International Nuclear Information System (INIS)

    Aboriginal peoples in the Canadian Arctic are exposed to persistent organic pollutants (POPs) and metals mainly through their consumption of a traditional diet of wildlife items. Recent studies indicate that many human chemical levels have decreased in the north, likely due to a combination of reduced global chemical emissions, dietary shifts, and risk mitigation efforts by local health authorities. Body burdens for chemicals in mothers can be further offset by breastfeeding, parity, and other maternal characteristics. We have assessed the impact of several dietary and maternal covariates following a decade of awareness of the contaminant issue in northern Canada, by performing multiple stepwise linear regression analyses from blood concentrations and demographic variables for 176 mothers recruited from Nunavut and the Northwest Territories during the period 2005–2007. A significant aboriginal group effect was observed for the modeled chemicals, except for lead and cadmium, after adjusting for covariates. Further, blood concentrations for POPs and metals were significantly associated with at least one covariate of older age, fewer months spent breastfeeding, more frequent eating of traditional foods, or smoking during pregnancy. Cadmium had the highest explained variance (72.5%) from just two significant covariates (current smoking status and parity). Although Inuit participants from the Northwest Territories consumed more traditional foods in general, Inuit participants from coastal communities in Nunavut continued to demonstrate higher adjusted blood concentrations for POPs and metals examined here. While this is due in part to a higher prevalence of marine mammals in the eastern Arctic diet, it is possible that other aboriginal group effects unrelated to diet may also contribute to elevated chemical body burdens in Canadian Arctic populations. - Highlights: • In 2005–07, younger age was related to lower levels of chemicals in northern Canada. • Eastern

  8. Annual CO2 budget and seasonal CO2 exchange signals at a High Arctic permafrost site on Spitsbergen, Svalbard archipelago

    Science.gov (United States)

    Lüers, J.; Westermann, S.; Piel, K.; Boike, J.

    2014-01-01

    The annual variability of CO2 exchange in most ecosystems is primarily driven by the activities of plants and soil microorganisms. However, little is known about the carbon balance and its controlling factors outside the growing season in arctic regions dominated by soil freeze/thaw-processes, long-lasting snow cover, and several months of darkness. This study presents a complete annual cycle of the CO2 net ecosystem exchange (NEE) dynamics for a High Arctic tundra area on the west coast of Svalbard based on eddy-covariance flux measurements. The annual cumulative CO2 budget is close to zero grams carbon per square meter per year, but shows a very strong seasonal variability. Four major CO2 exchange seasons have been identified. (1) During summer (ground snow-free), the CO2 exchange occurs mainly as a result of biological activity, with a predominance of strong CO2 assimilation by the ecosystem. (2) The autumn (ground snow-free or partly snow-covered) is dominated by CO2 respiration as a result of biological activity. (3) In winter and spring (ground snow-covered), low but persistent CO2 release occur, overlain by considerable CO2 exchange events in both directions associated with changes of air masses and air and atmospheric CO2 pressure. (4) The snow melt season (pattern of snow-free and snow-covered areas), where both, meteorological and biological forcing, resulting in a visible carbon uptake by the high arctic ecosystem. Data related to this article are archived under: http://doi.pangaea.de/10.1594/PANGAEA.809507.

  9. Heavy metal bioaccumulation and histopathological alterations in wild Arctic hares (Lepus arcticus) inhabiting a former lead-zinc mine in the Canadian high Arctic: A preliminary study.

    Science.gov (United States)

    Amuno, S; Niyogi, S; Amuno, M; Attitaq, J

    2016-06-15

    A preliminary study was undertaken to determine post-mining baseline accumulation of selected trace metals, and histopathological alterations in free-living arctic hares (Lepus arcticus) inhabiting the vicinity of a former lead-zinc mine located on North Baffin Island in the Canadian High Arctic. Trace metal analysis included measurement of As, Cd, Fe, Pb and Zn in tissues, and histopathological assessment comprised of evaluation and scoring the severity of metal-induced hepatic and renal lesions. Metal contents in hepatic and renal tissues from hares from the mine area compared with the reference locations did not differ significantly suggesting that the animals are not uniformly exposed to background levels of metals in the environment. However, relatively higher accumulation pattern of Pb and Cd were noted in liver tissues of hare from the mine area compared to the background area, but did not induce increased lesions. Surface soils near the mine area contained relatively higher levels of trace metals (Zn>Mn>Pb>Cd>As) compared to reference soils, and with soil levels of Cd showing strong correlation with Cd accumulation in kidney tissues. Generally, both case and reference animals showed similar but varying severities of hepatic and renal lesions at the sublethal level, notably vascular congestion, occasional large hepatocyte nuclei, binucleate hepatocytes, yellow-brown pigmentation in the cytoplasm of hepatocytes and clustering of lymphocytes. Only hares with relatively higher accumulation of Pb from the mine area showed evidence of renal edema and hemorrhage of the capsular surface. This study constitutes the first assessment of metal induced histopathological alterations in arctic hares exposed to a historical mining area in the high arctic. PMID:26974573

  10. Sedimentological and Paleoecological Records From the Central and Western Canadian Arctic in Relation to ice Core Paleoclimatic Data

    Science.gov (United States)

    Gajewski, K.; Peros, M.; Paull, T.; Fortin, M.; Finkelstein, S.; Ravindra, R.

    2007-12-01

    A series of lake sediment cores spanning the Holocene from across the central and western Canadian Arctic document ecosystem responses to climatic variations on several timescales. Sediment parameters (grain size, LOI, magnetic susceptibility) analyzed at very high resolution are used to quantify hydroclimatic variability at the watershed scale. Pollen, diatom, biogenic silica and chironomid series measured at high resolution show that the responses of terrestrial and aquatic organisms to millennial-scale climate variations are coeval with those variations interpreted from Greenland and Canadian ice core records. Climatic change caused large fluctuations in terrestrial production, as measured by pollen influx and concentrations, although biodiversity changes were less significant. Diatom stratigraphies are more complex, and show not only production changes but also diversity changes. These fluctuations are ultimately controlled by climate, but the direction and magnitude of changes in diatom assemblages are often determined by local factors such as habitat availability, lake size and nutrient status. Interpretation of chironomid records in relation to diatom-derived proxies for primary production indicate the combined impact of food source and climate on chironomid populations. Climate variations during the Holocene and the associated ecological impacts are sometimes comparable in rate and magnitude to those occurring now, suggesting paleoecological records from Arctic lakes can be used to better predict future impacts of climatic change.

  11. Biomarker responses associated with halogenated organic contaminants in northern fulmars (Fulmarus glacialis) breeding in the Canadian Arctic

    International Nuclear Information System (INIS)

    We examined relationships between hepatic concentrations of halogenated organic contaminants and ethoxyresorufin O-deethylase (EROD) activity and retinoid (vitamin A) concentrations in livers, as well as retinol and thyroid hormone (TT3, TT4) levels in blood plasma, of northern fulmars at two breeding colonies in the Canadian High Arctic. Biomarker levels or responses did not differ significantly between males and females at either colony, nor was there any significant difference between colonies. No significant relationships were found between thyroid hormone or hepatic retinoid concentrations and any of the dioxin-like compounds or their Toxic Equivalents (TEQs) although significant positive correlations were found with plasma retinol (p < 0.03). EROD activity was significantly correlated with hepatic dioxin-like compounds and their TEQs (p < 0.001) as well as total PCBs (p < 0.01), which suggests that EROD induction occurs in northern fulmars at environmentally-relevant concentrations. - Highlights: → EROD induction occurs in northern fulmars at environmentally-relevant concentrations. → No relationships between hepatic retinoid or plasma thyroid hormone levels and dioxin-like compounds or TEQs. → Biomarker responses did not differ between males and females or between colonies. - EROD induction occurs in northern fulmars in the Canadian Arctic at environmentally-relevant concentrations.

  12. Biomarker responses associated with halogenated organic contaminants in northern fulmars (Fulmarus glacialis) breeding in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Braune, Birgit M., E-mail: birgit.braune@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, K1A 0H3 (Canada); Trudeau, Suzanne [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, K1A 0H3 (Canada); Jeffrey, Deborah A. [Bancroft, Ontario, K0L 1C0 (Canada); Mallory, Mark L. [Environment Canada, Box 1714, Iqaluit, Nunavut, X0A 0H0 (Canada)

    2011-10-15

    We examined relationships between hepatic concentrations of halogenated organic contaminants and ethoxyresorufin O-deethylase (EROD) activity and retinoid (vitamin A) concentrations in livers, as well as retinol and thyroid hormone (TT{sub 3}, TT{sub 4}) levels in blood plasma, of northern fulmars at two breeding colonies in the Canadian High Arctic. Biomarker levels or responses did not differ significantly between males and females at either colony, nor was there any significant difference between colonies. No significant relationships were found between thyroid hormone or hepatic retinoid concentrations and any of the dioxin-like compounds or their Toxic Equivalents (TEQs) although significant positive correlations were found with plasma retinol (p < 0.03). EROD activity was significantly correlated with hepatic dioxin-like compounds and their TEQs (p < 0.001) as well as total PCBs (p < 0.01), which suggests that EROD induction occurs in northern fulmars at environmentally-relevant concentrations. - Highlights: > EROD induction occurs in northern fulmars at environmentally-relevant concentrations. > No relationships between hepatic retinoid or plasma thyroid hormone levels and dioxin-like compounds or TEQs. > Biomarker responses did not differ between males and females or between colonies. - EROD induction occurs in northern fulmars in the Canadian Arctic at environmentally-relevant concentrations.

  13. Assessing determinants of maternal blood concentrations for persistent organic pollutants and metals in the eastern and western Canadian Arctic.

    Science.gov (United States)

    Curren, Meredith S; Liang, Chun Lei; Davis, Karelyn; Kandola, Kami; Brewster, Janet; Potyrala, Mary; Chan, Hing Man

    2015-09-15

    Aboriginal peoples in the Canadian Arctic are exposed to persistent organic pollutants (POPs) and metals mainly through their consumption of a traditional diet of wildlife items. Recent studies indicate that many human chemical levels have decreased in the north, likely due to a combination of reduced global chemical emissions, dietary shifts, and risk mitigation efforts by local health authorities. Body burdens for chemicals in mothers can be further offset by breastfeeding, parity, and other maternal characteristics. We have assessed the impact of several dietary and maternal covariates following a decade of awareness of the contaminant issue in northern Canada, by performing multiple stepwise linear regression analyses from blood concentrations and demographic variables for 176 mothers recruited from Nunavut and the Northwest Territories during the period 2005-2007. A significant aboriginal group effect was observed for the modeled chemicals, except for lead and cadmium, after adjusting for covariates. Further, blood concentrations for POPs and metals were significantly associated with at least one covariate of older age, fewer months spent breastfeeding, more frequent eating of traditional foods, or smoking during pregnancy. Cadmium had the highest explained variance (72.5%) from just two significant covariates (current smoking status and parity). Although Inuit participants from the Northwest Territories consumed more traditional foods in general, Inuit participants from coastal communities in Nunavut continued to demonstrate higher adjusted blood concentrations for POPs and metals examined here. While this is due in part to a higher prevalence of marine mammals in the eastern Arctic diet, it is possible that other aboriginal group effects unrelated to diet may also contribute to elevated chemical body burdens in Canadian Arctic populations. PMID:25965033

  14. A Community-Based, Environmental Chronic Disease Prevention Intervention to Improve Healthy Eating Psychosocial Factors and Behaviors in Indigenous Populations in the Canadian Arctic

    Science.gov (United States)

    Mead, Erin L.; Gittelsohn, Joel; Roache, Cindy; Corriveau, André; Sharma, Sangita

    2013-01-01

    Diet-related chronic diseases are highly prevalent among indigenous populations in the Canadian Arctic. A community-based, multi-institutional nutritional and lifestyle intervention--Healthy Foods North--was implemented to improve food-related psychosocial factors and behaviors among Inuit and Inuvialuit in four intervention communities (with two…

  15. Large-scale temperature and salinity changes in the upper Canadian Basin of the Arctic Ocean at a time of a drastic Arctic Oscillation inversion

    Science.gov (United States)

    Bourgain, P.; Gascard, J. C.; Shi, J.; Zhao, J.

    2013-04-01

    Between 2008 and 2010, the Arctic Oscillation index over Arctic regions shifted from positive values corresponding to more cyclonic conditions prevailing during the 4th International Polar Year (IPY) period (2007-2008) to extremely negative values corresponding to strong anticyclonic conditions in 2010. In this context, we investigated the recent large-scale evolution of the upper western Arctic Ocean, based on temperature and salinity summertime observations collected during icebreaker campaigns and from ice-tethered profilers (ITPs) drifting across the region in 2008 and 2010. Particularly, we focused on (1) the freshwater content which was extensively studied during previous years, (2) the near-surface temperature maximum due to incoming solar radiation, and (3) the water masses advected from the Pacific Ocean into the Arctic Ocean. The observations revealed a freshwater content change in the Canadian Basin during this time period. South of 80° N, the freshwater content increased, while north of 80° N, less freshening occurred in 2010 compared to 2008. This was more likely due to the strong anticyclonicity characteristic of a low AO index mode that enhanced both a wind-generated Ekman pumping in the Beaufort Gyre and a possible diversion of the Siberian River runoff toward the Eurasian Basin at the same time. The near-surface temperature maximum due to incoming solar radiation was almost 1 °C colder in the southern Canada Basin (south of 75° N) in 2010 compared to 2008, which contrasted with the positive trend observed during previous years. This was more likely due to higher summer sea ice concentration in 2010 compared to 2008 in that region, and surface albedo feedback reflecting more sun radiation back in space. The Pacific water (PaW) was also subjected to strong spatial and temporal variability between 2008 and 2010. In the Canada Basin, both summer and winter PaW signatures were stronger between 75° N and 80° N. This was more likely due to a strong

  16. Photochemical and other sources of organic compounds in the Canadian high arctic aerosol pollution during winter-spring.

    Science.gov (United States)

    Fu, Pingqing; Kawamura, Kimitaka; Barrie, Leonard A

    2009-01-15

    Total suspended particles collected at Alert in the Canadian high Arctic (February-June) were analyzed for solvent extractable organic compounds using gas chromatography-mass spectrometry to better understand the sources and source apportionment of aerosol pollution that can affect the Arctic climate. More than 100 organic species were detected in the aerosols and were grouped into different compound classes based on the functional groups. Polyacids were found to be the most abundant compound class, followed by phthalates, aromatic acids, fatty acids, fatty alcohols, sugars/sugar alcohols, and n-alkanes, while polycyclic aromatic hydrocarbons, sterols, and lignin and resin acids were minor. Concentrations of total quantified organics seemed slightly higher in darkwinter aerosols (13.2-16.6 ng m(-3), average 14.5 ng m(-3)) than those after polar sunrise (6.70-17.7 ng m(-3), average 11.8 ng m(-3)). During dark winter, fossil fuel combustion products (30-51%), secondary oxidation products, as well as higher plant emissions were found as major contributors to the Arctic aerosols. However, after polar sunrise on 5 March, secondary oxidation products (5-53%) and plasticizer-derived phthalates became the dominant compound classes, followed by fossil fuel combustion and microbial/marine sources. Biomass burning emissions were found to contribute only 0.4-6% of the total identified organics, although they maximized in dark winter. This study demonstrates that long-range atmospheric transport, changes in the solar irradiance, and ambient temperature can significantly control the chemical composition of organic aerosols in the Arctic region. PMID:19238953

  17. Large-scale temperature and salinity changes in the upper Canadian basin of the Arctic Ocean at a time of a drastic Arctic Oscillation inversion

    Directory of Open Access Journals (Sweden)

    P. Bourgain

    2012-05-01

    Full Text Available Between 2008 and 2010, the Arctic Oscillation index over Arctic regions shifted from positive values corresponding to more cyclonic conditions prevailing during IPY period (2007–2008 to extremely negative values corresponding to strong anticyclonic conditions in 2010. In this context, we investigated the recent large scale evolution of the upper Western Arctic Ocean based on temperature and salinity summertime observations collected during icebreaker campaigns and from Ice-Tethered Platforms (ITP drifting across the region in 2008 and 2010. Particularly, we focused on (1 the freshwater content which was extensively studied during previous years, (2 the Near Surface Temperature Maximum due to incoming solar radiation and (3 the water masses advected from the Pacific and Atlantic Oceans into the deep Arctic Ocean.

    The observations revealed a freshwater content change in the Canadian basin during this time period. South of 80° N, the freshwater content increased, while north of 80° N, less freshening occurred in 2010 compared to 2008. This was more likely due to the strong anticyclonicity characteristic of a low AO index mode that enhanced both a wind-generated Ekman pumping in the Beaufort Gyre and a diversion of the Siberian rivers runoff toward the Eurasian basin at the same time.

    The Near Surface Temperature Maximum due to incoming solar radiation was almost 1 °C colder in the Southern Canada basin (south of 75° N in 2010 compared to 2008 which contrasted with the positive trend observed during previous years. This was more likely due to higher summer sea ice concentration in 2010 compared to 2008 in that region, and surface albedo feedback reflecting more sun radiation back in space.

    The Pacific waters were also subjected to strong spatial and temporal variability between 2008 and 2010. In the Canada basin, both Summer and Winter Pacific waters influence increased between 75° N and 80° N. This was more likely

  18. Dipole anomaly in the Arctic atmosphere and winter Arctic sea ice motion

    Institute of Scientific and Technical Information of China (English)

    WU; Bingyi; ZHANG; Renhe

    2005-01-01

    This paper investigates a previously-ignored atmospheric circulation anomaly-di- pole structure anomaly in the arctic atmosphere, and its relationship with the winter sea ice motion, based on analyses of the International Arctic Buoy Programme Data (1979-1998) and datasets from the National Center for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR) for the period of 1960-2002. The dipole structure anomaly is the second-leading mode of EOF of monthly mean SLP north of 70(N during the winter season (Oct.-Mar.), which accounts for 13% of the variance. One of its two anomaly centers is over the Canadian Archipelago; the other is situated over northern Eurasia and the Siberian marginal seas. Due to the dipole structure anomaly's strong meridionality, it becomes an important mechanism to drive both anomalous sea ice export out of the Arctic Basin and cold air outbreaks into the Barents Sea, the Nordic Seas and northern Europe.

  19. Optical Characterisation of Suspended Particles in the Mackenzie River Plume (Canadian Arctic Ocean) and Implications for Ocean Colour Remote Sensing

    Science.gov (United States)

    Doxaran, D.; Ehn, J.; Belanger, S.; Matsuoka, A.; Hooker, S.; Babin, M.

    2012-01-01

    Climate change significantly impacts Arctic shelf regions in terms of air temperature, ultraviolet radiation, melting of sea ice, precipitation, thawing of permafrost and coastal erosion. Direct consequences have been observed on the increasing Arctic river flow and a large amount of organic carbon sequestered in soils at high latitudes since the last glacial maximum can be expected to be delivered to the Arctic Ocean during the coming decade. Monitoring the fluxes and fate of this terrigenous organic carbon is problematic in such sparsely populated regions unless remote sensing techniques can be developed and proved to be operational. The main objective of this study is to develop an ocean colour algorithm to operationally monitor dynamics of suspended particulate matter (SPM) on the Mackenzie River continental shelf (Canadian Arctic Ocean) using satellite imagery. The water optical properties are documented across the study area and related to concentrations of SPM and particulate organic carbon (POC). Robust SPM and POC : SPM proxies are identified, such as the light backscattering and attenuation coefficients, and relationships are established between these optical and biogeochemical parameters. Following a semi-analytical approach, a regional SPM quantification relationship is obtained for the inversion of the water reflectance signal into SPM concentration. This relationship is reproduced based on independent field optical measurements. It is successfully applied to a selection of MODIS satellite data which allow estimating fluxes at the river mouth and monitoring the extension and dynamics of the Mackenzie River surface plume in 2009, 2010 and 2011. Good agreement is obtained with field observations representative of the whole water column in the river delta zone where terrigenous SPM is mainly constrained (out of short periods of maximum river outflow). Most of the seaward export of SPM is observed to occur within the west side of the river mouth. Future

  20. Contagious Ecthyma, Rangiferine Brucellosis, and Lungworm Infection in a Muskox ( Ovibos moschatus ) from the Canadian Arctic, 2014.

    Science.gov (United States)

    Tomaselli, Matilde; Dalton, Chimoné; Duignan, Pádraig J; Kutz, Susan; van der Meer, Frank; Kafle, Pratap; Surujballi, Om; Turcotte, Claude; Checkley, Sylvia

    2016-07-01

    An adult male muskox ( Ovibos moschatus ), harvested on 26 August 2014 on Victoria Island, Nunavut, in the Canadian Arctic, had proliferative dermatitis on the muzzle and fetlocks suggestive of contagious ecthyma or orf (Parapoxvirus). Histopathologic features of the lesions were consistent with this diagnosis. Orf virus DNA, phylogenetically similar to an isolate from a captive muskox of the Minnesota Zoo, US, was detected in the lesions by PCR using Parapoxvirus primers. Additionally, there was a metaphyseal abscess with a cortical fistula in the right metacarpus from which Brucella suis biovar 4 was isolated and identification supported by PCR. Brucella spp. antibodies were detected in serum. Finally, 212 nodules were dissected from the lungs. Fecal analysis and lung examination demonstrated co-infection with the lungworms Umingmakstrongylus pallikuukensis and Varestrongylus eleguneniensis. The zoonotic potential of orf and rangiferine brucellosis adds an important public health dimension to this case, particularly given that muskoxen are a valuable source of food for Arctic residents. Careful examination of these pathogens at a population level is needed as they may contribute to muskox population decline and potentially constitute a driver of food insecurity for local communities. This case underscores the importance of wildlife health surveillance as a management tool to conserve wildlife populations and maintain food security in subsistence-oriented communities. PMID:27285415

  1. Atmospheric concentrations of halogenated flame retardants at two remote locations: The Canadian High Arctic and the Tibetan Plateau

    International Nuclear Information System (INIS)

    Atmospheric concentrations of halogenated flame retardants (FRs) were monitored for approximately one year at two remote stations, namely Nam Co on the Tibetan Plateau and Alert in the Canadian High Arctic. BDE-47 and 99 were the dominant polybrominated diphenyl ether (PBDE) congeners at both sites. Atmospheric PBDE concentrations in Nam Co were generally lower than those at Alert. While significant seasonal variations were observed for PBDEs at Alert, the FR concentrations at Nam Co showed no significant seasonality, even though air masses originated from distinctly different regions during different seasons. This suggests that FRs in Tibet do not have regional sources, but are reflective of truly global background contamination. Three new FRs, namely 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate (EHTeBB) and bis(2-ethyl-1-hexyl)tetrabromophthalate (TBPH) were detected at relatively high concentrations at both sites. This is the first report of these FRs in the remote global atmosphere and suggests significant potential for long-range atmospheric transport. - Highlights: ► First year-round measurements of FRs in the atmosphere of the Tibetan Plateau. ► PBDEs in Tibet are reflective of truly global background levels. ► Orographic precipitation limits the transport of particle-bound chemicals. ► First study of BTBPE, EHTeBB and TBPH in the Arctic and Tibetan air. ► These new FRs may have significant long-range atmospheric transport potential. - Several brominated flame retardants (BTBPE, EHTeBB, TBPH) were present in the atmosphere of the Arctic and the Tibetan Plateau at levels similar to those of the PBDEs.

  2. Foraging ecology of ringed seals (Pusa hispida, beluga whales (Delphinapterus leucas and narwhals (Monodon monoceros in the Canadian High Arctic determined by stomach content and stable isotope analysis

    Directory of Open Access Journals (Sweden)

    Jordan K. Matley

    2015-05-01

    Full Text Available Stomach content and stable isotope analysis (δ13C and δ15N from liver and muscle were used to identify habitat and seasonal prey selection by ringed seals (Pusa hispida; n=21, beluga whales (Delphinapterus leucas; n=13 and narwhals (Monodon monoceros; n=3 in the eastern Canadian Arctic. Arctic cod (Boreogadus saida was the main prey item of all three species. Diet reconstruction from otoliths and stable isotope analysis revealed that while ringed seal size influenced prey selection patterns, it was variable. Prey-size selection and on-site observations found that ringed seals foraged on smaller, non-schooling cod whereas belugas and narwhals consumed larger individuals in schools. Further interspecific differences were demonstrated by δ13C and δ15N values and indicated that ringed seals consumed inshore Arctic cod compared to belugas and narwhals, which foraged to a greater extent offshore. This study investigated habitat variability and interseasonal variation in the diet of Arctic marine mammals at a local scale and adds to the sparse data sets available in the Arctic. Overall, these findings further demonstrate the critical importance of Arctic cod to Arctic food webs.

  3. Giardia assemblage A: human genotype in muskoxen in the Canadian Arctic

    OpenAIRE

    Nagy John; Wielinga Caroline M; Kandola Kami; Polley Lydden; Thompson RC Andrew; Kutz Susan J; Elkin Brett T

    2008-01-01

    Abstract As part of an ongoing program assessing the biodiversity and impacts of parasites in Arctic ungulates we examined 72 fecal samples from muskoxen on Banks Island, Northwest Territories, Canada for Giardia and Cryptosporidium. Cryptosporidium spp. were not detected, but 21% of the samples were positive for Giardia. Sequencing of four isolates of Giardia demonstrated G. duodenalis, Assemblage A, a zoonotic genotype.

  4. Changes in cold tolerance due to a 14-day stay in the Canadian Arctic

    Science.gov (United States)

    Livingstone, S. D.; Romet, T.; Keefe, A. A.; Nolan, R. W.

    1996-12-01

    Responses to cold exposure tests both locally and of the whole body were examined in subjects who stayed in the Arctic (average maximum and minimum temperatures -11 and -21° C respectively) for 14 days of skiing and sleeping in tents. These changes were compared to responses in subjects living working in Ottawa, Canada (average max. and min. temperatures -5 and -11° C respectively). The tests were done before the stay in the Arctic (Pre), immediately after the return (Post 1) and approximately 32 days after the return (Post 2). For the whole-body cold exposure each subject, wearing only shorts and lying on a rope mesh cot, was exposed to an ambient temperature of 10° C. There was no consistent response in the changes of metabolic or body temperature to this exposure in either of groups and, in addition, the changes over time were variable. Cold induced vasodilatation (CIVD) was determined by measuring temperature changes in the middle finger of the nondominant hand upon immersion in ice water for 30 min. CIVD was depressed after the Arctic exposure whilst during the Post 2 testing, although variable, did not return to the Pre values; the responses of the control group were similar. These results indicate that normal seasonal changes may be as important in adaptation as a stay in the Arctic. Caution is advised in the separation of seasonal effects when examining the changes in adaptation after exposure to a cold environment.

  5. Changes in temperature, precipitation and snow cover in the Arctic Sea region, 1981–2010

    OpenAIRE

    V. F. Radionov; E. I. Aleksandrov; N. N. Bryazgin; A. A. Dementiev

    2015-01-01

    The results of climatic generalization and analysis of the observation series on air temperature, precipitation and snow cover in the regions of the Arctic Seas and at the stations of the Canadian Archipelago to the north of 70° N are presented for the period 1981–2010. One uses data of meteorological observations at the permanent coastal and island stations and at the «North Pole» drifting stations and data from drifting buoys in the Arctic Basin. Quantitative estimates of the tendencies of ...

  6. A Prince's tribute...and trial. Monaco's Prince Albert II followed the footsteps of his great great grandfather when he ventured the Arctic Archipelago to trace climate change, this time with IAEA Marine scientists

    International Nuclear Information System (INIS)

    Monaco's Prince Albert II followed the footsteps of his great great grandfather when he ventured to the Arctic Archipelago to track climate change, this time with IAEA Marine scientists. He undertook this trip to draw global attention to the environmental damage to the Arctic regions caused by global warming. Although far away from industrialized areas, Svalbard Island is eminently suitable to observe the evolution of climate change and long-range pollutants transported from northern European countries by water currents and from North America by winds. Using nuclear techniques, it is hoped that some of the causes of climate change can be unlocked. The first of these studies was undertaken to evaluate the shell laminations of a very long-lived marine bivalve mollusc, the Ocean Quahog. The mollusc, with a life expectancy well over a century, acts as a recording of temperature variations and water chemistry. The second project aimed at determining levels of contaminates in marine zooplankton in remote arctic environments for comparison with other climatic regions

  7. Remediation of hydrocarbon contaminated soils in the Canadian Arctic with landfarms

    Energy Technology Data Exchange (ETDEWEB)

    Poland, J.S.; Page, J.A.; Paudyn, K.; Rutter, A.; Rowe, R.K. [Queen' s Univ., Kingston, ON (Canada)

    2007-07-01

    Landfarming is starting to gain acceptance as a bioremediation method in the Arctic despite scientific concerns that the kinetics associated with aeration and bioremediation are adversely impacted by cold temperatures. This paper provided details of a pilot study in which trial landfarm plots were assembled in order to compare 3 different landfarming techniques, notably (1) daily aeration; (2) aeration every 4 days; and (3) the addition of fertilizer with aeration every 4 days. The pilot study demonstrated that bioremediation was enhanced when fertilizer was added, and that aeration alone was a feasible option for the Arctic site. It was concluded that site selection is an important factor in the successful implementation of a landfarm. Factors affecting soil temperatures were also investigated. 8 refs., 7 figs.

  8. Giardia assemblage A: human genotype in muskoxen in the Canadian Arctic

    Directory of Open Access Journals (Sweden)

    Nagy John

    2008-09-01

    Full Text Available Abstract As part of an ongoing program assessing the biodiversity and impacts of parasites in Arctic ungulates we examined 72 fecal samples from muskoxen on Banks Island, Northwest Territories, Canada for Giardia and Cryptosporidium. Cryptosporidium spp. were not detected, but 21% of the samples were positive for Giardia. Sequencing of four isolates of Giardia demonstrated G. duodenalis, Assemblage A, a zoonotic genotype.

  9. Metagenomic Analysis of the Bioremediation of Diesel-Contaminated Canadian High Arctic Soils

    OpenAIRE

    Yergeau, Etienne; Sanschagrin, Sylvie; Beaumier, Danielle; Greer, Charles W.

    2012-01-01

    As human activity in the Arctic increases, so does the risk of hydrocarbon pollution events. On site bioremediation of contaminated soil is the only feasible clean up solution in these remote areas, but degradation rates vary widely between bioremediation treatments. Most previous studies have focused on the feasibility of on site clean-up and very little attention has been given to the microbial and functional communities involved and their ecology. Here, we ask the question: which microorga...

  10. Synchronous starphotometry and lidar measurements at Eureka in High Canadian Arctic

    OpenAIRE

    K. Baibakov; N. T. O'Neill; Ivanescu, L.; T. J. Duck; C. Perro; A. Herber; K.-H. Schulz; O. Schrems

    2015-01-01

    We present recent progress related to the night-time retrievals of aerosol and cloud optical depth using starphotometry over the PEARL (Polar Environmental Atmospheric Research Laboratory) station at Eureka (Nunavut, Canada) in the High Arctic (80° N, 86° W). In the spring of 2011 and 2012, the SPSTAR starphotometer was employed to acquire aerosol optical depth (AOD) measurements while vertical aerosol and cloud backscatter coefficient profiles were acquire...

  11. Inorganic carbon dynamics of melt pond-covered first year sea ice in the Canadian Arctic

    DEFF Research Database (Denmark)

    Geilfus, Nicolas-Xavier; Galley, R.J.; Crabeck, O.;

    2014-01-01

    of this high concentration pCO2 melt water increase the in situ brine pCO2 within the sea ice matrix. The low in situ pCO2 observed in brine and melt ponds results in CO2 fluxes of −0.04 to −5.4 mmol m–2 d–1. As melt ponds reach equilibrium with the atmosphere, the uptake becomes less significant. However......, since melt ponds are continuously supplied by melt water their in situ pCO2 still remains low, promoting a continuous but moderate uptake of CO2 (~ −1mmol m–2 d–1). The potential uptake of atmospheric CO2 by melting sea ice during the Arctic summer has been estimated from 7 to 16 Tg of C ignoring...... the role of melt ponds. This additional uptake of CO2 associated to Arctic sea ice needs to be further explored and considered in the estimation of the Arctic Ocean's overall CO2 budget....

  12. Factors affecting biotic mercury concentrations and biomagnification through lake food webs in the Canadian high Arctic

    International Nuclear Information System (INIS)

    In temperate regions of Canada, mercury (Hg) concentrations in biota and the magnitude of Hg biomagnification through food webs vary between neighboring lakes and are related to water chemistry variables and physical lake features. However, few studies have examined factors affecting the variable Hg concentrations in landlocked Arctic char (Salvelinus alpinus) or the biomagnification of Hg through their food webs. We estimated the food web structure of six high Arctic lakes near Resolute Bay, Nunavut, Canada, using stable carbon (δ13C) and nitrogen (δ15N) isotopes and measured Hg (total Hg (THg) in char, the only fish species, and methylmercury (MeHg) in chironomids and zooplankton) concentrations in biota collected in 2010 and 2011. Across lakes, δ13C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ15N (of char and benthic invertebrates) showed positive and significant slopes, indicting Hg biomagnification in all lakes, and higher slopes in some lakes than others. However, no principal components (PC) generated using all water chemistry data and physical characteristics of the lakes predicted the different slopes. The PC dominated by aqueous ions was a negative predictor of MeHg concentrations in chironomids, suggesting that water chemistry affects Hg bioavailability and MeHg concentrations in these lower-trophic-level organisms. Furthermore, regression intercepts were predicted by the PCs dominated by catchment area, aqueous ions, and MeHg. Weaker relationships were also found between THg in small char or MeHg in pelagic invertebrates and the PCs dominated by catchment area, and aqueous nitrate and MeHg. Results from these high Arctic lakes suggest that Hg biomagnification differs between systems and that their physical and chemical characteristics affect Hg concentrations in lower-trophic-level biota. - Highlights: • Mercury (Hg) in Arctic char and invertebrates from 6 Arctic lakes were

  13. Factors affecting biotic mercury concentrations and biomagnification through lake food webs in the Canadian high Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Lescord, Gretchen L., E-mail: glescord@gmail.com [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kidd, Karen A. [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kirk, Jane L. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada); O' Driscoll, Nelson J. [Acadia University, 15 University Ave, Wolfville, NS B4P 2R6 (Canada); Wang, Xiaowa; Muir, Derek C.G. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada)

    2015-03-15

    In temperate regions of Canada, mercury (Hg) concentrations in biota and the magnitude of Hg biomagnification through food webs vary between neighboring lakes and are related to water chemistry variables and physical lake features. However, few studies have examined factors affecting the variable Hg concentrations in landlocked Arctic char (Salvelinus alpinus) or the biomagnification of Hg through their food webs. We estimated the food web structure of six high Arctic lakes near Resolute Bay, Nunavut, Canada, using stable carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopes and measured Hg (total Hg (THg) in char, the only fish species, and methylmercury (MeHg) in chironomids and zooplankton) concentrations in biota collected in 2010 and 2011. Across lakes, δ{sup 13}C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ{sup 15}N (of char and benthic invertebrates) showed positive and significant slopes, indicting Hg biomagnification in all lakes, and higher slopes in some lakes than others. However, no principal components (PC) generated using all water chemistry data and physical characteristics of the lakes predicted the different slopes. The PC dominated by aqueous ions was a negative predictor of MeHg concentrations in chironomids, suggesting that water chemistry affects Hg bioavailability and MeHg concentrations in these lower-trophic-level organisms. Furthermore, regression intercepts were predicted by the PCs dominated by catchment area, aqueous ions, and MeHg. Weaker relationships were also found between THg in small char or MeHg in pelagic invertebrates and the PCs dominated by catchment area, and aqueous nitrate and MeHg. Results from these high Arctic lakes suggest that Hg biomagnification differs between systems and that their physical and chemical characteristics affect Hg concentrations in lower-trophic-level biota. - Highlights: • Mercury (Hg) in Arctic char and invertebrates

  14. Modern to millennium-old greenhouse gases emitted from ponds and lakes of the Eastern Canadian Arctic (Bylot Island, Nunavut)

    Science.gov (United States)

    Bouchard, F.; Laurion, I.; Prėskienis, V.; Fortier, D.; Xu, X.; Whiticar, M. J.

    2015-12-01

    Ponds and lakes are widespread across the rapidly changing permafrost environments. Aquatic systems play an important role in global biogeochemical cycles, especially in greenhouse gas (GHG) exchanges between terrestrial systems and the atmosphere. The source, speciation and emission rate of carbon released from permafrost landscapes are strongly influenced by local conditions, hindering pan-Arctic generalizations. This study reports on GHG ages and emission rates from aquatic systems located on Bylot Island, in the continuous permafrost zone of the Eastern Canadian Arctic. Dissolved and ebullition gas samples were collected during the summer season from different types of water bodies located in a highly dynamic periglacial valley: polygonal ponds, collapsed ice-wedge trough ponds, and larger lakes. The results showed strikingly different ages and fluxes depending on aquatic system types. Polygonal ponds were net sinks of dissolved CO2, but variable sources of dissolved CH4. They presented the highest ebullition fluxes, 1 or 2 orders of magnitude higher than from other ponds and lakes. Trough ponds appeared as substantial GHG sources, especially when their edges were actively eroding. Both types of ponds produced modern to hundreds of years old ( 2000 yr BP) derived from freshly eroded peat. Lakes had small dissolved and ebullition fluxes, however they released much older GHG, including millennium-old CH4 (up to 3500 yr BP) from lake central areas. Acetoclastic methanogenesis dominated at all study sites and there was minimal, if any, methane oxidation in gas emitted through ebullition. These findings provide new insights on GHG emissions by permafrost aquatic systems and their potential positive feedback effect on climate.

  15. Landscape and Hydrological Transformation in the Canadian High Arctic: Climate Change and Permafrost Degradation As Drivers of Change

    Science.gov (United States)

    Lamoureux, S. F.; Lafreniere, M. J.

    2014-12-01

    Recent climate warming and landscape instability arising from permafrost degradation in the Canadian High Arctic have resulted in significant changes to the hydrological system. We have undertaken an integrated watershed and permafrost research program at the Cape Bounty Arctic Watershed Observatory (75°N, 109°W) in paired watershed-lake systems to assess the impact of these changes. Research has captured hydrological changes resulting from exceptional warmth, and permafrost degradation and disturbance. Results highlight the contrasting effect of thermal (deeper soil thaw) versus physical perturbation (slope failures and permafrost degradation). Thermal perturbation applies to most of the landscape, and results indicate that ground ice melt alters flow and mobilizes solutes for a number of years following a single warm year. These effects are measureable at the slope-catchment scale, especially during baseflow. By contrast, physical disturbance is highly localized and produces high sediment and particulate carbon erosion from slopes, but downstream particulate delivery is dependent on surface connectivity. Recovery from disturbances appears to occur rapidly, and continued geomorphic change and new slope channels result in sustained delivery of particulates to channels. The result is increased long term landscape heterogeneity with respect to erosion compared to the pre-disturbance condition. Downstream channel response to particulate loading further dampens the response to physical disturbance through channel storage of material. Hence, at the larger watershed scale, the effect of physical perturbation is minimal in the initial years of recovery. These results point to a landscape that has been substantially impacted by recent hydrological and permafrost changes. Understanding and distinguishing these impacts provides a basis for systematically evaluating biogeochemical cycling and ecosystem responses in aquatic settings.

  16. Possible effects of climate warming on selected populations of polar bears (Ursus maritimus) in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Stirling, I. [Canadian Wildlife Service, Edmonton, AB (Canada); Parkinson, C.L. [NASA Goddard Space Flight Center, Greenbelt, MD (United States). Cryospheric Sciences Branch

    2006-09-15

    Climate warming in the Arctic has caused declines in the total cover and thickness of sea ice. Intuit hunters in the areas of some polar bear populations in the eastern Canadian Arctic have noted that more bears have approached human settlements during open-water periods in recent years. The observations have been interpreted as evidence of increasing polar bear population size, and have resulted in increases in hunting quotas. However, research on 2 polar bear populations in Western Hudson Bay and Baffin Bay suggest that their numbers are declining. This paper evaluated patterns of sea-ice breakup and freeze-up in 5 regions to test the hypothesis that sightings of more polar bears are due in part to changes in sea ice. The regions were based on the accepted boundaries of the polar bear management zones used by government agencies in Canada and Greenland. Areas included Foxe Basin; Baffin Bay; Davis Strait; Hudson Strait; and Eastern Hudson Bay. Analysis of passive-microwave satellite imagery beginning in the 1970s has indicated that sea ice is breaking up at progressively earlier dates, so that bears must fast for longer periods during the open-water periods. This paper suggested that polar bears are being observed close to human settlements as they are searching for alternative food sources in years when their stored body fat is depleted before freeze-up, when they can return to the sea ice to hunt for seals. It was suggested that if the climate continues to warm as projected by the Intergovernmental Panel on Climate Change, polar bears in all 5 populations discussed in the paper will become increasingly food-stressed, and that their numbers are likely to decline. It was suggested that problem interactions between bears and humans will also increase as the bears seek alternative food sources. It was concluded that a precautionary approach should be taken to the harvesting of polar bears. The potential effects of climate warming should be incorporated into

  17. Late Holocene Vegetation and Climate Change From the Central and Western Canadian Arctic Inferred From Fossil Pollen Data

    Science.gov (United States)

    Peros, M.; Gajewski, K.

    2007-12-01

    Two sediment cores from the central and western Canadian Arctic were used to document landscape-scale vegetation and climate changes spanning the last ~2500 years. Both cores were dated by Pb-210 and C-14 techniques. Fossil pollen was enumerated at continuous 1 cm intervals (each centimeter representing a period of ~70 years), permitting centennial-scale changes to be placed into a long-term context. The pollen percentages are dominated by Cyperaceae and show relatively uniform values throughout the cores. Quantitative climate reconstructions, based on the percentage values, are similarly stable. However, the influx of locally- and regionally-derived pollen grains increases over the last ~150 years, suggesting that higher primary production and summer temperatures occurred over this time. The pollen results from these cores are consistent with other high-resolution (~25 year) lake sediment proxy data (BSi and LOI) from the region. Despite this, a comparison of these data with several Holocene-length pollen records from the same region indicates that the changes that characterized the last 2000 years were relatively minor compared to those of the early Holocene.

  18. Single-island home range use by four female Peary caribou, Bathurst Island, Canadian High Arctic, 1993-94

    Directory of Open Access Journals (Sweden)

    Frank L. Miller

    2003-04-01

    Full Text Available Spatial and temporal use of seasonal, and collectively, annual ranges by four female Peary caribou (Rangifer taran-dus pearyi was investigated using satellite telemetry. Knowledge of how caribou use space allows a better understanding of their demands on those ranges and enhances evaluation of associated environmental stressors. The study took place during an environmentally favorable caribou-year with high reproduction and calf survival and low (none detected 1+ yr-old mortality, 1 August 1993 to 31 July 1994, Bathurst Island, south-central Queen Elizabeth Islands, Canadian High Arctic. All four females exhibited a pattern of single-island seasonal, and collectively, annual range use. Estimates of the maximum area encompassed by each individual during the course of the annual-cycle varied from 1735 to 2844 km2 (mean±SE = 2284±250 km2. Although, there was 46% spatial overlap among individual ranges, temporal isolation resulted in the four individuals maintaining seasonal ranges distinctly separate from each other. This collective area encompassed 4970 km2 and equaled about 31% and 18% of Bathurst Island and the Bathurst Island complex, respectively. Individual wintering areas formed a relatively small portion of each individual's annual range (mean±SE=71±17 km2: 24 km2, 158 days of occupation, <1% of the annual area; 70 km2, 187 days, 4%; 95 km2, 200 days, 4%; and 94 km2, 172 days, 6%. Seasonal movements were greatest during pre-rut and pre-calving.

  19. Achievements and challenges on policies for allied health professionals who use telehealth in the Canadian Arctic.

    Science.gov (United States)

    Hailey, D; Foerster, V; Nakagawa, B; Wapshall, T M; Murtagh, J A; Smitten, J; Steblecki, J A; Wong, G

    2005-01-01

    We formulated policies and procedures for allied health professionals (AHPs) who provide services using telehealth in Nunavut, Canada's newest Arctic territory. These are a supplement to the clinical policies and procedures already established for Nunavut physicians and nurses. The services were in the areas of audiology, dietetics/nutrition, midwifery, occupational therapy, ophthalmic services, pharmacy, physiotherapy, psychology, respiratory therapy, social work and speech therapy. Documents specific to each of the services were developed, drawing on information from Government of Nunavut data, Nunavut healthcare providers and links made through the Internet. Topics included the scope and limitations of telehealth services, staff responsibilities, training and reporting, professional standards and cultural considerations. We also considered generic policies covering common issues such as jurisdiction, licensing and liability. The policies and procedures for AHPs will enhance and expand the successes already achieved with telehealth in Nunavut. The challenges are to balance the preferred approaches to service provision with the realities of health care and communications in an Arctic setting. PMID:16375792

  20. The Expression of the 8.2 ka and Younger Dryas Events in the Eastern Canadian Arctic

    Science.gov (United States)

    Miller, G. H.; Wolfe, A. P.; Briner, J. P.; Nesje, A.

    2004-12-01

    The two largest climate coolings following the end of the last glaciation are the Younger Dryas and the 8.2 ka events. Evidence for these cold excursions is widespread around the North Atlantic and in more distant regions. Both events are well expressed in Greenland ice cores; glacier readvances occurred across much of NW Europe during the Younger Dryas and cold surface waters returned to the North Atlantic, with depressed summer temperatures in eastern North America. The 8.2 ka event has a similar pattern, but the magnitude is substantially lower, with a much shorter duration. However, surprisingly little evidence has been presented for either event from the North Atlantic Arctic. Recently acquired lake sediment records from the Eastern Canadian Arctic contain evidence for both excursions. The 8.2 ka event is recorded at two sites as a significant glacier readvance of cirque and outlet glaciers of local ice caps at 8.2±0.1 ka. In some non-glacially-dominated lakes, a reduction in primary productivity is apparent at the same time. These records suggest colder summers without a dramatic reduction in precipitation, producing positive mass balances and glacier readvances. For most local glaciers, this was the last significant readvance before they receded behind their Little Ice Age margins. Only a few lakes contain records that extend through the Younger Dryas chron. The best-dated lake record, Donard Lake, extends back to 15 ka. Lacustrine sedimentation is currently dominated by a meltwater from an outlet glacier that terminates a few hundred meters from the lake. The glacier has been within the drainage basin of the lake for the past 5.5 ka, although the contribution of glacial sediment has been larger since about 2.5 ka. Prior to 5.5 ka, there is no evidence of a glacier in the catchment of Donard Lake, suggesting that throughout the entire Neoglacial period, the local glacier has been more advanced than at any time since 15 ka. During the Younger Dryas chron

  1. Metagenomic analysis of the bioremediation of diesel-contaminated Canadian high arctic soils.

    Directory of Open Access Journals (Sweden)

    Etienne Yergeau

    Full Text Available As human activity in the Arctic increases, so does the risk of hydrocarbon pollution events. On site bioremediation of contaminated soil is the only feasible clean up solution in these remote areas, but degradation rates vary widely between bioremediation treatments. Most previous studies have focused on the feasibility of on site clean-up and very little attention has been given to the microbial and functional communities involved and their ecology. Here, we ask the question: which microorganisms and functional genes are abundant and active during hydrocarbon degradation at cold temperature? To answer this question, we sequenced the soil metagenome of an ongoing bioremediation project in Alert, Canada through a time course. We also used reverse-transcriptase real-time PCR (RT-qPCR to quantify the expression of several hydrocarbon-degrading genes. Pseudomonas species appeared as the most abundant organisms in Alert soils right after contamination with diesel and excavation (t = 0 and one month after the start of the bioremediation treatment (t = 1m, when degradation rates were at their highest, but decreased after one year (t = 1y, when residual soil hydrocarbons were almost depleted. This trend was also reflected in hydrocarbon degrading genes, which were mainly affiliated with Gammaproteobacteria at t = 0 and t = 1m and with Alphaproteobacteria and Actinobacteria at t = 1y. RT-qPCR assays confirmed that Pseudomonas and Rhodococcus species actively expressed hydrocarbon degradation genes in Arctic biopile soils. Taken together, these results indicated that biopile treatment leads to major shifts in soil microbial communities, favoring aerobic bacteria that can degrade hydrocarbons.

  2. The influence of Arctic haze and radiatively active trace gases on the arctic climate

    International Nuclear Information System (INIS)

    Increasing fossil fuel consumption and industrial activities have raised concerns of possible man-induced climate changes. The changes result mostly from increased radiatively active trace gases (RAG) and anthropogenic aerosols in the atmosphere. Among the by-products of combustion, carbon dioxide is the leading RAG. Fossil fuel combustion also generates sulfates and soot, the principal constituents of the Arctic haze. Both CO2 and Arctic haze interact with radiative processes to produce external climate forcing. Due to their strong tendency to absorb visible solar radiation, soot particles result in strong diabatic heating in the Arctic. With a mixing ratio of 10-10, a concentration 1 million times less than H2O, the solar radiative heating produced by particulate soot is still comparable to that of H2O. The Canadian Climate Centre (CCC) has recently completed a climate simulation with a double carbon dioxide scenario. Version 2 of the CCC-GCM includes a mixed-layer ocean and thermodynamic ice model. It allows for the evaluation of climate changes due to an external forcing. The aim of this paper is to compare the climate changes induced by increasing CO2 and Arctic haze. Since both signals are occurring simultaneously, the authors must investigate the individual contributions with a climate model. A preliminary sensitivity study of the Arctic haze (February to May) with interactive sea ice was done. The analysis suggests that the excess of solar radiative heating leads to increasing rates of snow and ice melt during spring and summer. The most sensitive regions are the Canadian Arctic Archipelago and the Greenland Sea. In both regions, the ice is substantially reduced. The anomaly of sea ice amount continues its propagation northward in June and July even though the Arctic haze is absent during that period

  3. Buried glacier ice in permafrost, a window to the past: examples from Bylot Island, Canadian Arctic

    Science.gov (United States)

    Fortier, D.; Coulombe, S.; Kanevskiy, M. Z.; Paquette, M.; Shur, Y.; Stephani, E.

    2011-12-01

    Bylot Island is located north of Baffin Island (73°N, 80°W) and is extensively covered by an ice cap and its outlet glaciers flowing towards the arctic lowland of the Lancaster formation. During summers of 2009 and 2011 several active-layer detachment slides exposed large massive ice bodies and other types of debris-rich ice that were interpreted as buried glacier ice. The upper part of the massive ice and debris-rich ice were usually in contact with various types of ice-contact or glacio-fluvial sediments and in some cases they were covered by mass wasting/colluvial deposits. This suggests that their preservation was likely related to burial of the ice and refreezing of the overlying sediments following permafrost aggradation. A preliminary analysis of the ice facies and ice crystals revealed the presence of four distinct types of ice: 1) clear-ice bodies with very few sediment and no organic inclusions. The ice crystals were large (cm), randomly oriented and air bubbles were observed at the junction of crystals. These characteristics could potentially indicate an englacial (snow-neve metamorphism) origin for these clear ice bodies; 2) large, meter thick, clear ice layers with no sediment, nor organics. The ice crystals were large (cm), several cm long, oriented in the same direction, and vertically aligned. These characteristics could potentially point to water that refroze in a tunnel incised in englacial ice; 3) Successive, mm to cm thick, ice layers, separated by undulating sand and gravel bands also containing cobles to boulder size rock fragments. These characteristics could potentially represent regelation ice formed at the base of glaciers and incorporated to the glacier sole; 4) mm to cm suspended aggregate of fine-grained sediments in clear ice. These micro-suspended and suspended cryostructures were sometimes deformed and aligned in the form of thin (mm) undulating layers. These micro-structures were very similar to basal ice facies, presumably

  4. Microbial characterization of a subzero, hypersaline methane seep in the Canadian High Arctic.

    Science.gov (United States)

    Niederberger, Thomas D; Perreault, Nancy N; Tille, Stephanie; Lollar, Barbara Sherwood; Lacrampe-Couloume, Georges; Andersen, Dale; Greer, Charles W; Pollard, Wayne; Whyte, Lyle G

    2010-10-01

    We report the first microbiological characterization of a terrestrial methane seep in a cryo-environment in the form of an Arctic hypersaline (∼24% salinity), subzero (-5 °C), perennial spring, arising through thick permafrost in an area with an average annual air temperature of -15 °C. Bacterial and archaeal 16S rRNA gene clone libraries indicated a relatively low diversity of phylotypes within the spring sediment (Shannon index values of 1.65 and 1.39, respectively). Bacterial phylotypes were related to microorganisms such as Loktanella, Gillisia, Halomonas and Marinobacter spp. previously recovered from cold, saline habitats. A proportion of the bacterial phylotypes were cultured, including Marinobacter and Halomonas, with all isolates capable of growth at the in situ temperature (-5 °C). Archaeal phylotypes were related to signatures from hypersaline deep-sea methane-seep sediments and were dominated by the anaerobic methane group 1a (ANME-1a) clade of anaerobic methane oxidizing archaea. CARD-FISH analyses indicated that cells within the spring sediment consisted of ∼84.0% bacterial and 3.8% archaeal cells with ANME-1 cells accounting for most of the archaeal cells. The major gas discharging from the spring was methane (∼50%) with the low CH(4)/C(2+) ratio and hydrogen and carbon isotope signatures consistent with a thermogenic origin of the methane. Overall, this hypersaline, subzero environment supports a viable microbial community capable of activity at in situ temperature and where methane may behave as an energy and carbon source for sustaining anaerobic oxidation of methane-based microbial metabolism. This site also provides a model of how a methane seep can form in a cryo-environment as well as a mechanism for the hypothesized Martian methane plumes. PMID:20445635

  5. Synchronous starphotometry and lidar measurements at Eureka in High Canadian Arctic

    Directory of Open Access Journals (Sweden)

    K. Baibakov

    2015-02-01

    Full Text Available We present recent progress related to the night-time retrievals of aerosol and cloud optical depth using starphotometry over the PEARL (Polar Environmental Atmospheric Research Laboratory station at Eureka (Nunavut, Canada in the High Arctic (80° N, 86° W. In the spring of 2011 and 2012, the SPSTAR starphotometer was employed to acquire aerosol optical depth (AOD measurements while vertical aerosol and cloud backscatter coefficient profiles were acquired using the CANDAC Raman Lidar (CRL. Several events were detected and characterized using starphotometry-lidar synergy: aerosols (short term aerosol events on 9 and 10 March 2011; a potential multi-night aerosol event across three polar nights (13–15 March 2012, a thin cloud event (21 February 2011 and a very low altitude ice crystals (10 March 2011. Using a simple backscatter coefficient threshold criterion we calculated fine and coarse (sub and super-micron mode AODs from the vertically integrated CRL profiles. These were compared with their starphotometry analogues produced from a spectral deconvolution algorithm. The process-level analysis showed, in general, good agreement in terms of the physical coherence between high frequency starphotometry and lidar data. We argue that R2 (coefficient of determination is the most robust means of comparing lidar and starphotometer data since it is sensitive to significant optico-physical variations associated with these two independent data sources while being minimally dependent on retrieval and calibration artifacts. Differences between the fine and course mode components of the starphotometry and lidar data is clearly also useful but is more dependent on such artifacts. Studying climatological seasonal aerosol trends necessitates effective cloud-screening procedures: temporal and spectral cloud screening of starphotometry data was found to agree moderately well with temporal cloud screening results except in the presence of thin homogeneous cloud

  6. Synchronous starphotometry and lidar measurements at Eureka in High Canadian Arctic

    Science.gov (United States)

    Baibakov, K.; O'Neill, N. T.; Ivanescu, L.; Duck, T. J.; Perro, C.; Herber, A.; Schulz, K.-H.; Schrems, O.

    2015-02-01

    We present recent progress related to the night-time retrievals of aerosol and cloud optical depth using starphotometry over the PEARL (Polar Environmental Atmospheric Research Laboratory) station at Eureka (Nunavut, Canada) in the High Arctic (80° N, 86° W). In the spring of 2011 and 2012, the SPSTAR starphotometer was employed to acquire aerosol optical depth (AOD) measurements while vertical aerosol and cloud backscatter coefficient profiles were acquired using the CANDAC Raman Lidar (CRL). Several events were detected and characterized using starphotometry-lidar synergy: aerosols (short term aerosol events on 9 and 10 March 2011); a potential multi-night aerosol event across three polar nights (13-15 March 2012), a thin cloud event (21 February 2011) and a very low altitude ice crystals (10 March 2011). Using a simple backscatter coefficient threshold criterion we calculated fine and coarse (sub and super-micron) mode AODs from the vertically integrated CRL profiles. These were compared with their starphotometry analogues produced from a spectral deconvolution algorithm. The process-level analysis showed, in general, good agreement in terms of the physical coherence between high frequency starphotometry and lidar data. We argue that R2 (coefficient of determination) is the most robust means of comparing lidar and starphotometer data since it is sensitive to significant optico-physical variations associated with these two independent data sources while being minimally dependent on retrieval and calibration artifacts. Differences between the fine and course mode components of the starphotometry and lidar data is clearly also useful but is more dependent on such artifacts. Studying climatological seasonal aerosol trends necessitates effective cloud-screening procedures: temporal and spectral cloud screening of starphotometry data was found to agree moderately well with temporal cloud screening results except in the presence of thin homogeneous cloud. We conclude

  7. Concentrations of mercury in tissues of beluga whales (Delphinapterus leucas) from several communities in the Canadian Arctic from 1981 to 2002.

    Science.gov (United States)

    Lockhart, W L; Stern, G A; Wagemann, R; Hunt, R V; Metner, D A; DeLaronde, J; Dunn, B; Stewart, R E A; Hyatt, C K; Harwood, L; Mount, K

    2005-12-01

    Beluga whales have been hunted for food by Native People in the Canadian Arctic since prehistoric time. Here we report the results of analyses of total mercury in samples of liver, kidney, muscle and muktuk from collections over the period 1981-2002. We compare these results with human consumption guidelines and examine temporal and geographic variation. Liver has been analyzed more frequently than other organs and it has been used as the indicator organ. Mercury accumulates in the liver of the whales over time so that the whale ages are usually linked statistically to their levels of mercury in liver. Virtually all the samples of 566 animals analyzed contained mercury in liver at concentrations higher than the Canadian consumption guideline of 0.5 microg g-1 (wet weight) for fish. (There is no regulatory guideline for concentrations in marine mammals in Canada.) Samples from locations in the Mackenzie Delta in the western Canadian Arctic and from Pangnirtung in the eastern Canadian Arctic were obtained more often than from other location and these offered the best chances to determine whether levels have changed over time. Statistical outlier points were removed and the regressions of (ln) mercury in liver on age were used to calculate the level of mercury in whales of age 13.1 years in order to compare age-adjusted levels at different locations. These age-adjusted levels and also the slopes of regressions suggested that levels have increased in the Mackenzie Delta over the sampling period although not in a simple linear fashion. Other locations had fewer collections, generally spread over fewer years. Some of them indicated differences between sampling times but we could not establish whether these differences were simply temporal variation or whether they were segments of a consistent trend. For example, the levels in whales from Arviat were considerably higher in 1999 than in 1984 but we have only two samples. Similarly, samples from Iqaluit in 1994 exceeded

  8. Composition and meteorological changes associated with a strong stratospheric intrusion event in the Canadian High Arctic

    Science.gov (United States)

    Zhao, Xiaoyi; Strong, Kimberly; Conway, Stephanie; Tarasick, David; Osman, Mohammed; Richter, Andreas; Blechschmidt, Anne; Manney, Gloria

    2015-04-01

    Stratosphere-troposphere exchange (STE) provides a mechanism for trace gas transport between the lower stratosphere and the troposphere. Intense downward stratospheric intrusions may significantly affect the oxidizing capacity of the troposphere. Most STE events occur in tropical and mid-latitude regions, with less known about STE in the polar regions. In this work, we present an observation and modelling study of a strong stratospheric intrusion in the high Arctic (Eureka, 80°N) in March 2013, which led to an increase of total ozone and BrO columns observed by both ground-based and satellite instruments. The meteorological conditions for this event were similar to those observed for STEs associated with cold fronts. Before the cold front arrived at Eureka, the surface temperature first increased from -25.3°C (25 March 13:00 UTC) to -14.5°C (27 March 20:00 UTC) and then dropped to -36.4°C (29 March 6:00 UTC) after the front passed by. Meanwhile, the ground-level pressure decreased from 103.8 kPa to 101.8 kPa, then rose back to 102.6 kPa. Ozonesonde data (27 March 23:15 UTC) showed unusually high ozone (>100 ppbv) above ~3 km altitude, while the relative humidity profile indicated that the airmass was of stratospheric origin (very low relative humidity). The thermal tropopause height was ~9 km, based on a uniform lapse rate of 3.9 K/km from surface to 9 km. From ECMWF Interim data, the airmass with high relative potential vorticity (4 pvu) extended down to 3 km. In addition, HYSPLIT model ensemble back-trajectories show a clear Rossby wave signature in the upper troposphere during this event, which could explain the intrusion. However, there are no strong downwelling layers along the trajectories, which indicates that the intrusion may have occurred close to Eureka. Trace gas composition data from three ground-based spectrometers and the GOME-2 satellite instrument are presented in this work. Ozone vertical column densities (VCDs) measured by two Zenith

  9. Middle Pleistocene (?) buried glacial ice on Bylot Island, Canadian Arctic Archipleago

    Science.gov (United States)

    Fortier, D.; Godin, E.; Kanevskiy, M. Z.; Allard, M.

    2009-12-01

    Bylot Island is located north of Baffin Island (73°N, 80°W). More than the half of the island is covered by an ice cap and its outlet glaciers flowing towards the arctic lowland of the Lancaster formation. The study site comprises four main stratigraphic units. Overlying the shales (Tertiary) of the Lancaster Formation (500 m a.s.l.), a diamicton (unit 1) is covered by a “fossil forest-tundra” sequence (unit 2) containing abundant remains of trees and plants (Allard et al., submitted). Paleontological correlation of extinct species and reverse to normal palomagnetism polarities suggest a Late Pliocene to Early Pleistocene age for this unit. A sequence (unit 3) of ice-contact proximal to distal glacio-fluvial sediments overlies the organic beds. Paleomagnetic analysis showed that the upper glacio-fluvial sediments were likely deposited during the Brunhes polarity chron (younger than 0.73 Ma). The uppermost unit (unit 4) consists in a lodgement till containing clasts of Paleozoic limestone erratics. Based on amino acid ratios of shells fragments in the drift, Klassen (1993) suggested that this “foreign drift” was probably deposited during an "old" Quaternary glaciation named “Baffin glaciation” During July 2009 several active-layer detachment slides at the head of large gullies exposed large massive ice bodies located at the junction between units 3 and 4. A preliminary analysis of the ice facies and ice crystals revealed the presence of two distinct types of massive ice: 1) clear-ice bodies with very few sediments and no organic inclusions. The ice crystals were large (cm) and air bubbles were observed at the junction of crystals. These characteristics could potentially indicate an englacial origin for these clear ice bodies. In some places, the ice was stratified with undulating layers of sands and gravels. These micro-structures are very similar to basal ice facies we observed at the Matanuska Glacier in Alaska. The exposed massive ice sections were

  10. Impact of Holocene climate variability on Arctic vegetation

    Science.gov (United States)

    Gajewski, K.

    2015-10-01

    This paper summarizes current knowledge about the postglacial history of the vegetation of the Canadian Arctic Archipelago (CAA) and Greenland. Available pollen data were used to understand the initial migration of taxa across the Arctic, how the plant biodiversity responded to Holocene climate variability, and how past climate variability affected primary production of the vegetation. Current evidence suggests that most of the flora arrived in the area during the Holocene from Europe or refugia south or west of the region immediately after local deglaciation, indicating rapid dispersal of propagules to the region from distant sources. There is some evidence of shrub species arriving later in Greenland, but it is not clear if this is dispersal limited or a response to past climates. Subsequent climate variability had little effect on biodiversity across the CAA, with some evidence of local extinctions in areas of Greenland in the late Holocene. The most significant impact of climate changes is on vegetation density and/or plant production.

  11. (U-Th)/He Ages of Detrital Zircons From Paleozoic Strata of the Severnaya Zemlya Archipelago (Russian High Arctic): implication for testing the different tectonic models

    Science.gov (United States)

    Ershova, Victoria; Anfinson, Owen; Prokopiev, Andrei; Khudoley, Andrei; Stockli, Daniel; Faleide, Jan Inge; Gaina, Carmen; Malyshev, Nikolay

    2016-04-01

    The Severnaya Zemlya archipelago comprises four main islands (Pioneer, October Revolution, Komsomolets and Bol'shevik), along with numerous other small islands, islets and island groups. It contains rocks varying in age from Late Cambrian to Permian and is a key area for understanding the tectonic evolution of the North Kara and Laptev Sea basins. Various models have been proposed for the Paleozoic history of the Kara Terrane: 1) Kara terrane inferred as a part of a larger continent block called Arctida (Zonenshain et al, 1990). 2) Lorenz et al. (2008a, 2008b) described the Kara terrane as a marginal part of Baltica. 3) The Kara Terrane existed as a separate terrane or microcontinent during the Paleozoic (Bogdanov et al., 1998; Gramberg & Ushakov, 2000; Metelkin et al., 2000, 2005) Here we present (U-Th)/He ages of detrital zircons collected from Ordovician - Devonian strata of Pioneer and October Revolution islands) along with Sedov Islands. All detrital zircon (U-Th)/He ages are older than age of host rocks indicating the samples were not buried deep enough (less than ~6-8 km) to reset the (U-Th)/He isotopic system. Thus, (U-Th)/He ages indicate the exhumational history of the clastic source region. The (U-Th)/He detrital zircon ages from Ordovician- Silurian strata, with a peak age of ca. 465 Ma, suggest the primary source region was located within the Caledonian Orogen, which is unknown in the modern vicinity of Severnaya Zemlya. The abundance of Caledonian (U-Th)/He zircon ages in the studied samples suggests a continuation of Caledonides northeastward across Barents shelf as previously inferred from pre-Permo-Carboniferous rifting restoration and illustrated by geophysical data. In contrast to older clastic rocks, (U-Th)/He detrital zircon ages from the Devonian deposits show a mixture of Ellesmerian and Caledonian ages with age peaks at ca. 365 Ma and 465 Ma and the youngest grains nearing the depositional age of the strata. The ages suggest the clastic

  12. Graduate training in Earth science across borders and disciplines: ArcTrain -"Processes and impacts of climate change in the North Atlantic Ocean and the Canadian Arctic"

    Science.gov (United States)

    Stein, Rüdiger; Kucera, Michal; Walter, Maren; de Vernal, Anne

    2015-04-01

    Due to a complex set of feedback processes collectively known as "polar amplification", the Arctic realm is expected to experience a greater-than-average response to global climate forcing. The cascades of feedback processes that connect the Arctic cryosphere, ocean and atmosphere remain incompletely constrained by observations and theory and are difficult to simulate in climate models. Our capacity to predict the future of the region and assess the impacts of Arctic change processes on global and regional environments hinges on the availability of interdisciplinary experts with strong international experience and understanding of the science/society interface. This is the basis of the International Research Training Group "Processes and impacts of climate change in the North Atlantic Ocean and the Canadian Arctic - ArcTrain", which was initiated in 2013. ArcTrain aims to educate PhD students in an interdisciplinary environment that combines paleoclimatology, physical oceanography, remote sensing and glaciology with comprehensive Earth system modelling, including sea-ice and ice-sheet components. The qualification program for the PhD students includes joint supervision, mandatory research residences at partner institutions, field courses on land and on sea (Floating University), annual meetings and training workshops and a challenging structured training in expert skills and transferrable skills. Its aim is to enhance the career prospects and employability of the graduates in a challenging international job market across academic and applied sectors. ArcTrain is a collaborative project at the University of Bremen and the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven. The German part of the project is designed to continue for nine years and educate three cohorts of twelve PhD students each. The Canadian partners comprise a consortium of eight universities led by the GEOTOP cluster at the Université du Québec à Montréal and including

  13. Search for latitudinal trends in the effective half-life of fallout sup(137)Cs in vegetation of the Canadian arctic

    International Nuclear Information System (INIS)

    Using published data on the integrated deposition of fallout sup(90)Sr(sup(137)Cs) until 1975 and current measurements of the sup(137)Cs activity in plant communities along the latitudinal gradient north of 50 degrees N, an estimate has been made of the sup(137)Cs effective half-life, Tsub(eff), in the composite vegetation of the Canadian arctic. The lichens Alectoria nigricans, Alectoria ochroleuca, Cladonia rangiferina, Cornicularia divergens, and Umbilicaria muhlenbergii were studied, as well as a moss, Polytrichum juniperinum, and the vascular cushion plants Dryas integrifolia, Saxifraga oppositifolia, and Silene acaulis. In all cases, the effective half-life increases with increasing latitude, the longest Tsub(eff)(10-12 years) being exhibited by dry-habitat lichens at 80 degrees N

  14. A 1.5-D anisotropic sigma-coordinate thermal stress model of landlocked sea ice in the Canadian Arctic Archipelago

    Science.gov (United States)

    Hata, Y.; Tremblay, L. B.

    2015-12-01

    We present a 1.5-D thermal stress model that takes into account the effect of land confinement, which causes anisotropy in thermal stresses. To this end, we fix the total strain in the direction perpendicular to the coastline to its value at landlocked ice onset. This prevents thermal expansion in the direction perpendicular to the coastline and therefore induces larger thermal stresses in this direction. The simulated stresses best match the observations, when a Young's Modulus of 0.5 GPa and a relaxation time constant of 8 days are used. This simulation gives root-mean-square errors of 13.0 and 13.1 kPa (˜15%) in the major and minor principal stresses, respectively. The simulated anisotropic component of thermal stress also generally agrees with observations. The optimal Young's Modulus is in the low range of reported values in the literature, and the optimal relaxation time constant (8 days) is larger than the largest relaxation time constant reported in the literature (5 days). A series of experiments are done to examine the model sensitivity to vertical resolution, snow cover, and the parameterizations of Young's Modulus and viscous creep. Results show that a minimum of one and three layers in the snow and ice, respectively, is required to simulate the thermal stresses within 15% error of the value assessed with the higher-resolution control simulation. This highlights the importance of resolving the internal snow and ice vertical temperature profile in order to properly model the thermal stresses of sea ice.

  15. Longer ice-free seasons increase the risk of nest depredation by polar bears for colonial breeding birds in the Canadian Arctic.

    Science.gov (United States)

    Iverson, Samuel A; Gilchrist, H Grant; Smith, Paul A; Gaston, Anthony J; Forbes, Mark R

    2014-03-22

    Northern polar regions have warmed more than other parts of the globe potentially amplifying the effects of climate change on biological communities. Ice-free seasons are becoming longer in many areas, which has reduced the time available to polar bears (Ursus maritimus) to hunt for seals and hampered bears' ability to meet their energetic demands. In this study, we examined polar bears' use of an ancillary prey resource, eggs of colonial nesting birds, in relation to diminishing sea ice coverage in a low latitude region of the Canadian Arctic. Long-term monitoring reveals that bear incursions onto common eider (Somateria mollissima) and thick-billed murre (Uria lomvia) nesting colonies have increased greater than sevenfold since the 1980s and that there is an inverse correlation between ice season length and bear presence. In surveys encompassing more than 1000 km of coastline during years of record low ice coverage (2010-2012), we encountered bears or bear sign on 34% of eider colonies and estimated greater egg loss as a consequence of depredation by bears than by more customary nest predators, such as foxes and gulls. Our findings demonstrate how changes in abiotic conditions caused by climate change have altered predator-prey dynamics and are leading to cascading ecological impacts in Arctic ecosystems. PMID:24500172

  16. A Possible Feedback Mechanism Involving the Arctic Freshwater,the Arctic Sea Ice, and the North Atlantic Drift

    Institute of Scientific and Technical Information of China (English)

    Odd Helge OTTER(A); Helge DRANGE

    2004-01-01

    Model studies point to enhanced warming and to increased freshwater fluxes to high northern latitudes in response to global warming. In order to address possible feedbacks in the ice-ocean system in response to such changes, the combined effect of increased freshwater input to the Arctic Ocean and Arctic warming--the latter manifested as a gradual melting of the Arctic sea ice--is examined using a 3-D isopycnic coordinate ocean general circulation model. A suite of three idealized experiments is carried out: one control integration, one integration with a doubling of the modern Arctic river runoff, and a third more extreme case, where the river runoff is five times the modern value. In the two freshwater cases, the sea ice thickness is reduced by 1.5-2 m in the central Arctic Ocean over a 50-year period. The modelled ocean response is qualitatively the same for both perturbation experiments: freshwater propagates into the Atlantic Ocean and the Nordic Seas, leading to an initial weakening of the North Atlantic Drift.Furthermore, changes in the geostrophic currents in the central Arctic and melting of the Arctic sea ice lead to an intensified Beaufort Gyre, which in turn increases the southward volume transport through the Canadian Archipelago. To compensate for this southward transport of mass, more warm and saline Atlantic water is carried northward with the North Atlantic Drift. It is found that the increased transport of salt into the northern North Atlantic and the Nordic Seas tends to counteract the impact of the increased freshwater originating from the Arctic, leading to a stabilization of the North Atlantic Drift.

  17. Temporal and spatial variabilities of atmospheric polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and polycyclic aromatic hydrocarbons (PAHs) in the Canadian Arctic: results from a decade of monitoring.

    Science.gov (United States)

    Hung, H; Blanchard, P; Halsall, C J; Bidleman, T F; Stern, G A; Fellin, P; Muir, D C G; Barrie, L A; Jantunen, L M; Helm, P A; Ma, J; Konoplev, A

    2005-04-15

    The Northern Contaminants Program (NCP) baseline monitoring project was established in 1992 to monitor for persistent organic pollutants (POPs) in Arctic air. Under this project, weekly samples of air were collected at four Canadian and two Russian arctic sites, namely Alert, Nunavut; Tagish, Yukon; Little Fox Lake, Yukon; Kinngait, Nunavut; Dunai Island, Russia and Amderma, Russia. Selected POPs, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides, were analyzed in both the gas and particulate phases. This paper summarizes results obtained from this project in the past 5 years. Temporal trends were developed for atmospheric PCBs and OCs observed at Alert using a digital filtration (DF) technique. It was found that trends developed with 5 years of data (1993-1997) did not differ significantly from those determined with 7 years of data (1993-1999). This implies that with the DF technique, long-term trends can still be developed with less than 10 years of data. An acceleration in decline of OC and PCB air concentrations was noted in 1999 for some compounds, although the reason is unknown. Monitoring efforts must continue to assess the effect of this decline on the long-term trends of POPs in the Canadian Arctic. Occasional high trans-/cis-chlordane ratios and heptachlor air concentrations measured at Alert between 1995 and 1997 suggests sporadic fresh usage of chlordane-based pesticides. However, significant decreasing trends of chlordanes along with their chemical signatures has provided evidence that emission of old soil residues is replacing new usage as an important source to the atmosphere. Measurements of OC air concentrations conducted at Kinngait in 1994-1995 and 2000-2001 indicated faster OC removal at this location than at Alert. This may be attributed to the proximity of Kinngait to temperate regions where both biotic and abiotic degradation rates are faster. The PAH concentrations observed

  18. Nuanced Perceptions and Arctic Disputes

    DEFF Research Database (Denmark)

    Burke, Danita Catherine

    -depth consideration and analysis. As such, this thesis explores the complexities and evolution of the Canadian-Arctic relationship through two central research questions: how have the dominant cultural attitudes about the Canadian Arctic emerged and evolved within Canadian society and how have these cultural ideas...... interests and disputes in the Canadian Arctic region at the regional and international levels are affects by domestic cultural and political factors. The thesis was submitted in May 2015 and successfully defended in September 2015. The external examiner was Professor Philip Steinberg (Professor in the...

  19. Baseline monitoring of the western Arctic Ocean estimates 20% of Canadian basin surface waters are undersaturated with respect to aragonite.

    Directory of Open Access Journals (Sweden)

    Lisa L Robbins

    Full Text Available Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification. Here, based on more than 34,000 data records collected in 2010 and 2011, we establish a baseline of inorganic carbon data (pH, total alkalinity, dissolved inorganic carbon, partial pressure of carbon dioxide, and aragonite saturation index for the western Arctic Ocean. This data set documents aragonite undersaturation in ≈ 20% of the surface waters of the combined Canada and Makarov basins, an area characterized by recent acceleration of sea ice loss. Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation. These data link the Arctic Ocean's largest area of aragonite undersaturation to sea ice melt and atmospheric CO2 absorption in areas of low buffering capacity. Some relatively supersaturated areas can be linked to localized biological activity. Collectively, these observations can be used to project trends of ocean acidification in higher latitude marine surface waters where inorganic carbon chemistry is largely influenced by sea ice meltwater.

  20. Baseline monitoring of the western Arctic Ocean estimates 20% of Canadian Basin surface waters are undersaturated with respect to aragonite

    Science.gov (United States)

    Robbins, Lisa L.; Wynn, Jonathan G.; Lisle, John T.; Yates, Kimberly K.; Knorr, Paul O.; Byrne, Robert H.; Liu, Xuewu; Patsava, Mark C.; Azetsu-Scott, Kumiko; Takahashi, Taro

    2013-01-01

    Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification. Here, based on more than 34,000 data records collected in 2010 and 2011, we establish a baseline of inorganic carbon data (pH, total alkalinity, dissolved inorganic carbon, partial pressure of carbon dioxide, and aragonite saturation index) for the western Arctic Ocean. This data set documents aragonite undersaturation in ~20% of the surface waters of the combined Canada and Makarov basins, an area characterized by recent acceleration of sea ice loss. Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation. These data link the Arctic Ocean’s largest area of aragonite undersaturation to sea ice melt and atmospheric CO2 absorption in areas of low buffering capacity. Some relatively supersaturated areas can be linked to localized biological activity. Collectively, these observations can be used to project trends of ocean acidification in higher latitude marine surface waters where inorganic carbon chemistry is largely influenced by sea ice meltwater.

  1. Eddy length scales and the Rossby radius in the Arctic Ocean

    Directory of Open Access Journals (Sweden)

    A. J. G. Nurser

    2013-10-01

    Full Text Available The first (and second baroclinic deformation (or Rossby radii are presented and discussed north of ~60° N, focusing on deep basins and shelf seas in the high Arctic Ocean, the Nordic Seas, Baffin Bay, Hudson Bay and the Canadian Arctic Archipelago, derived from high-resolution ice-ocean general circulation model output. Comparison of the model output with measured results shows that low values of the Rossby radius (in shallow water and high values (in the Canada Basin are accurately reproduced, while intermediate values (in the region of the Makarov and Amundsen Basins are overestimated. In the high Arctic Ocean, the first Rossby radius increases from ~5 km in the Nansen Basin to ~15 km in the central Canadian Basin. In the shelf seas and elsewhere, values are low (1–7 km, reflecting weak density stratification, shallow water, or both. Seasonality only strongly impacts the Rossby radii in shallow seas where winter homogenisation of the water column can reduce it to the order of 100 m. We also offer an interpretation and explanation of the observed scales of Arctic Ocean eddies.

  2. A trajectory analysis of atmospheric transport of black carbon aerosols to Canadian high Arctic in winter and spring (1990–2005

    Directory of Open Access Journals (Sweden)

    L. Huang

    2010-06-01

    Full Text Available Black carbon (BC particles accumulated in the Arctic troposphere and deposited on snow have been calculated to have significant effects on radiative forcing of the Arctic regional climate. Applying cluster analysis technique on 10-day backward trajectories, seven distinct transport pathways (or clusters affecting Alert (82.5° N, 62.5° W, Nunavut in Canada are identified in this work. Transport frequency associated with each pathway is obtained as the fraction of trajectories in that cluster. Based on atmospheric transport frequency and BC surface flux from surrounding regions (i.e. North America, Europe, and former USSR, a linear regression model is constructed to investigate the inter-annual variations of BC observed at Alert in January and April, representative of winter and spring respectively, between 1990 and 2005. Strong correlations are found between BC concentrations predicted with the regression model and measurements at Alert for both seasons (R2 equals 0.77 and 0.81 for winter and spring, respectively. Results imply that atmospheric transport and BC emission are the major contributors to the inter-annual variations in BC concentrations observed at Alert in the cold seasons for the 16-year period. Other factors, such as deposition, could also contribute to the variability in BC concentrations but were not considered in this analysis. Based on the regression model the relative contributions of regional BC emissions affecting Alert are attributed to the Eurasian sector, composed of the European Union and the former USSR, and the North American sector. Considering both seasons, the model suggests that former USSR is the major contributor to the near-surface BC levels at the Canadian high Arctic site with an average contribution of about 67% during the 16-year period, followed by European Union (18% and North America (15%. In winter, the atmospheric transport of BC aerosols from Eurasia is found to be even more

  3. Mercury distribution in the skin of beluga (Delphinapterus leucas) and narwhal (Monodon monoceros) from the Canadian Arctic and mercury burdens and excretion by moulting.

    Science.gov (United States)

    Wagemann, R; Kozlowska, H

    2005-12-01

    Beluga and narwhal skin as a whole (in Inuktitut known as "muktuk") is considered to be a delicacy by native Canadian and Greenland people. Individual strata of the skin, and muscle from 27 beluga from the western, and 20 narwhal from the eastern Canadian Arctic, were analyzed for mercury and the thickness and density of each skin layer was measured. Mercury was not uniformly distributed in the skin, but increased outwardly with each layer. The concentration was only 0.29 and 0.16 microg/g (wet wt) in the innermost layer (dermis) of belugas and narwhal respectively, and 1.5 and 1.4 microg/g (wet wt) in the outermost layer (degenerative epidermis) of beluga and narwhal, respectively. There was a significant (alpha=0.05) association between age and mercury concentration in each skin layer, the regression coefficients progressively increasing from the inner layer (dermis) to the outer layer: 0.011-0.063 microg/g year-1; 0.034 microg/g year-1 for skin as a whole; 0.054 microg/g year-1 for muscle. The concentration of total mercury was 0.84 and 0.59 microg/g (wet wt) in skin as a whole (muktuk) of beluga and narwhal respectively, and 0.12 and 0.03 microg/g in blubber, respectively. The average, total mercury concentration in muscle tissue was 1.4 and 0.81 microg/g wet wt, in beluga and narwhal respectively, exceeding (except for blubber) the Canadian Government's Guideline (0.5 microg/g wet wt) for fish export and consumption. The skin surface area of an average-size beluga and narwhal was estimated (6.10 and 6.50 m2, respectively), as were excretions of mercury through moulting (13,861 and 6721 microg year-1; 14 and 7 mg year-1) for belugas and narwhal, respectively. The whole-body mercury burden (699,300 microg; 700 mg) for a 1000 kg beluga and its various tissues were estimated, as was the fraction of mercury excreted by moulting (2-0.42% of the whole-body burden). Annual mercury burden increments in beluga skin, muscle and the whole body were estimated (2750; 17

  4. What we know, do not know, and need to know about climate change vulnerability in the western Canadian Arctic: a systematic literature review

    International Nuclear Information System (INIS)

    This letter systematically reviews and synthesizes scientific and gray literature publications (n = 420) to identify and characterize the nature of climate change vulnerability in the Inuvialuit Settlement Region of the western Canadian Arctic and identify gaps in understanding. The literature documents widespread evidence of climate change, with implications for human and biophysical systems. Adaptations are being employed to manage changing conditions and are indicative of a high adaptive capacity. However, barriers to adaptation are evident and are expected to constrain adaptive capacity to future climate change. Continued climate change is predicted for the region, with differential exposure sensitivity for communities, groups and sectors: a function of social-economic-biophysical characteristics and projected future climatic conditions. Existing climate risks are expected to increase in magnitude and frequency, although the interaction between projected changes and socio-economic-demographic trends has not been assessed. The capacity for adapting to future climate change has also not been studied. The review identifies the importance of targeted vulnerability research that works closely with community members and other stakeholders to address research needs. Importantly, the fully categorized list of reviewed references accompanying this letter will be a valuable resource for those working or planning to work in the region, capturing climate change research published since 1990. At a broader level, the systematic review methodology offers a promising tool for climate/environmental change studies in general where there is a large and emerging body of research but limited understanding of research gaps and needs.

  5. Evaluation of radionuclide levels and radiological dose in three populations of marine mammals in the eastern Canadian Arctic

    International Nuclear Information System (INIS)

    Radionuclide levels were measured in beluga, walrus and ringed seal populations collected in 1992 to assess radiation dose and changes in dose with age and sex. The authors hypothesized that Arctic marine food chains accumulate high levels of naturally-occurring radionuclides such as polonium-210 and that radiation may pose a stress to animals which also accumulate metals such as cadmium. Liver, kidney, muscle and jawbone were analyzed by gamma spectrometry for cesium-137, cesium-134, lead-210, potassium-40 and radium-226 and fission-derived nuclides. Polonium-210 was analyzed by alpha spec after autodeposition onto a silver disk. Cesium-137 concentrations in muscle in all three populations were low, and ranged from below detection limits to 10 Bq/kg ww. There was no evidence of fission-derived radionuclides such as zinc-65 or cobalt-60. Lead-210 levels ranged from below detection limits in muscle of ringed seal and walrus to a mean of 82.3 Bq/kg ww in walrus bone. Polonium-210 in the three population ranged from 10 to 30 Bq/kg ww in bone and kidney. The major contributor to dose in the animals was polonium-210 because it is an alpha emitter and accumulates to moderate levels in liver and kidney. Radiological dose is approximately 20--30 times higher than background in humans, and is considerably lower than the dose observed in terrestrial food chains in the Arctic

  6. Tectonic Map of the Ellesmerian and Eurekan deformation belts on Svalbard, North Greenland and the Queen Elizabeth Islands (Canadian Arctic)

    Science.gov (United States)

    Piepjohn, Karsten; von Gosen, Werner; Tessensohn, Franz; Reinhardt, Lutz; McClelland, William C.; Dallmann, Winfried; Gaedicke, Christoph; Harrison, Christopher

    2016-04-01

    The tectonic map presented here shows the distribution of the major post-Ellesmerian and pre-Eurekan sedimentary basins, parts of the Caledonian Orogen, the Ellesmerian Fold-and-Thrust Belt, structures of the Cenozoic Eurekan deformation, and areas affected by the Eurekan overprint. The present continental margin of North America towards the Arctic Ocean between the Queen Elizabeth Islands and Northeast Greenland and the present west margin of the Barents Shelf are characterized by the Paleozoic Ellesmerian Fold-and-Thrust Belt, the Cenozoic Eurekan deformation, and, in parts, the Caledonian Orogen. In many areas, the structural trends of the Ellesmerian and Eurekan deformations are more or less parallel, and often, structures of the Ellesmerian Orogeny are affected or reactivated by the Eurekan deformation. While the Ellesmerian Fold-and-Thrust Belt is dominated by orthogonal compression and the formation of wide fold-and-thrust zones on Ellesmere Island, North Greenland and Spitsbergen, the Eurekan deformation is characterized by a complex network of regional fold-and-thrust belts (Spitsbergen, central Ellesmere Island), large distinct thrust zones (Ellesmere Island, North Greenland) and a great number of strike-slip faults (Spitsbergen, Ellesmere Island). The Ellesmerian Fold-and-Thrust Belt was most probably related to the approach and docking of the Pearya Terrane (northernmost part of Ellesmere Island) and Spitsbergen against the north margin of Laurasia (Ellesmere Island/North Greenland) in the earliest Carboniferous. The Eurekan deformation was related to plate tectonic movements during the final break-up of Laurasia and the opening of Labrador Sea/Baffin Bay west, the Eurasian Basin north, and the Norwegian/Greenland seas east of Greenland. The tectonic map presented here shows the German contribution to the Tectonic Map of the Arctic 1:5,000,000 (TeMAr) as part of the international project "Atlas of geological maps of Circumpolar Arctic at 1

  7. Controls on Weathering of Pyrrhotite in a Low-Sulfide, Granitic Mine-Waste Rock in the Canadian Arctic

    Science.gov (United States)

    Langman, J. B.; Holland, S.; Sinclair, S.; Blowes, D.

    2013-12-01

    Increased environmental risk is incurred with expansion of mineral extraction in the Arctic. A greater understanding of geochemical processes associated with hard-rock mining in this cold climate is needed to evaluate and mitigate these risks. A laboratory and in-situ experiment was conducted to examine mineral weathering and the generation of acid rock drainage in a low-sulfide, run-of-mine waste rock in an Arctic climate. Rock with different concentrations of sulfides (primarily pyrrhotite [Fe7S8] containing small amounts of Co and Ni) and carbonates were weathered in the laboratory and in-situ, large-scale test piles to examine leachate composition and mineral weathering. The relatively larger sulfide-containing rock produced sufficient acid to overcome carbonate buffering and produced a declining pH environment with concomitant release of SO4, Fe, Co, and Ni. Following carbonate consumption, aluminosilicate buffering stabilized the pH above 4 until a reduction in acid generation. Results from the laboratory experiment assisted in determining that after consumption of 1.6 percent of the total sulfide, the larger sulfide-concentration test pile likely is at an internal steady-state or maximal weathering rate after seven years of precipitation input and weathering that is controlled by an annual freeze-thaw cycle. Further weathering of the test pile should be driven by external factors of temperature and precipitation in this Arctic, semi-arid region instead of internal factors of wetting and non-equilibrium buffering. It is predicted that maximal weathering will continue until at least 20 percent of the total sulfide is consumed. Using the identified evolution of sulfide consumption in this Arctic climate, a variable rate factor can now be assessed for the possible early evolution and maximal weathering of larger scale waste-rock piles and seasonal differences because of changes in the volume of a waste-rock pile undergoing active weathering due to the freeze

  8. Relationships between estimates of ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Stirling, I. [Canadian Wildlife Service, Edmonton, AB (Canada); Oritsland, N.A. [Norsk Polarinstitutt, Oslo (Norway)

    1995-12-01

    Biological studies were conducted in arctic marine areas to assess the possible impacts of industrial development and to identify areas of critical habitat that might warrant some degree of protection. Ringed seals were studied since polar bears depend on them for food and both species are of cultural and economic importance to the Inuit. The number of seals needed to support a population of polar bears was estimated independently using both behavioral and energetic data. Predation and energy matrices indicated that high levels of predation on seals were sustainable only if most animals killed were young-of-the-year. Densities of seals and the productivity of bears appeared to vary in direct proportion to each other, indicating a high level of sensitivity of relationship between ringed seals and polar bears, at the population level. 86 refs., 6 tabs., 5 figs.

  9. Study of Heavy Metals in a Wetland Area Adjacent to a Waste Disposal Site Near Resolute Bay, Canadian High Arctic

    Science.gov (United States)

    Lund, K. E.; Young, K. L.

    2004-05-01

    Heavy metal contamination in High Arctic systems is of growing concern. Studies have been conducted measuring long range and large point source pollutants, but little research has been done on small point sources such as municipal waste disposal sites. Many Arctic communities are coastal, and local people consume marine wildlife in which concentrations of heavy metals can accumulate. Waste disposal sites are often located in very close proximity to the coastline and leaching of these metals could contaminate food sources on a local scale. Cadmium and lead are the metals focussed on by this study, as the Northern Contaminants Program recognizes them as metals of concern. During the summer of 2003 a study was conducted near Resolute, Nunavut, Canada, to determine the extent of cadmium and lead leaching from a local dumpsite to an adjacent wetland. The ultimate fate of these contaminants is approximately 1 km downslope in the ocean. Transects covering an area of 0.3 km2 were established downslope from the point of disposal and water and soil samples were collected and analyzed for cadmium and lead. Only trace amounts of cadmium and lead were found in the water samples. In the soil samples, low uniform concentrations of cadmium were found that were slightly above background levels, except for adjacent to the point of waste input where higher concentrations were found. Lead soil concentrations were higher than cadmium and varied spatially with soil material and moisture. Overall, excessive amounts of cadmium and lead contamination do not appear to be entering the marine ecosystem. However, soil material and moisture should be considered when establishing waste disposal sites in the far north

  10. Ship emissions measurement in the Arctic by plume intercepts of the Canadian Coast Guard icebreaker Amundsen from the Polar 6 aircraft platform

    Science.gov (United States)

    Aliabadi, Amir A.; Thomas, Jennie L.; Herber, Andreas B.; Staebler, Ralf M.; Leaitch, W. Richard; Schulz, Hannes; Law, Kathy S.; Marelle, Louis; Burkart, Julia; Willis, Megan D.; Bozem, Heiko; Hoor, Peter M.; Köllner, Franziska; Schneider, Johannes; Levasseur, Maurice; Abbatt, Jonathan P. D.

    2016-06-01

    Decreasing sea ice and increasing marine navigability in northern latitudes have changed Arctic ship traffic patterns in recent years and are predicted to increase annual ship traffic in the Arctic in the future. Development of effective regulations to manage environmental impacts of shipping requires an understanding of ship emissions and atmospheric processing in the Arctic environment. As part of the summer 2014 NETCARE (Network on Climate and Aerosols) campaign, the plume dispersion and gas and particle emission factors of effluents originating from the Canadian Coast Guard icebreaker Amundsen operating near Resolute Bay, NU, Canada, were investigated. The Amundsen burned distillate fuel with 1.5 wt % sulfur. Emissions were studied via plume intercepts using the Polar 6 aircraft measurements, an analytical plume dispersion model, and using the FLEXPART-WRF Lagrangian particle dispersion model. The first plume intercept by the research aircraft was carried out on 19 July 2014 during the operation of the Amundsen in the open water. The second and third plume intercepts were carried out on 20 and 21 July 2014 when the Amundsen had reached the ice edge and operated under ice-breaking conditions. Typical of Arctic marine navigation, the engine load was low compared to cruising conditions for all of the plume intercepts. The measured species included mixing ratios of CO2, NOx, CO, SO2, particle number concentration (CN), refractory black carbon (rBC), and cloud condensation nuclei (CCN). The results were compared to similar experimental studies in mid-latitudes. Plume expansion rates (γ) were calculated using the analytical model and found to be γ = 0.75 ± 0.81, 0.93 ± 0.37, and 1.19 ± 0.39 for plumes 1, 2, and 3, respectively. These rates were smaller than prior studies conducted at mid-latitudes, likely due to polar boundary layer dynamics, including reduced turbulent mixing compared to mid-latitudes. All emission factors were in agreement with prior

  11. Vitamin A and E profiles as biomarkers of PCB exposure in beluga whales (Delphinapterus leucas) from the western Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Desforges, Jean-Pierre W. [University of Victoria, School of Earth and Ocean Sciences, 3800 Finnerty Road, Victoria, BC, Canada V8P 5C2 (Canada); Fisheries and Oceans Canada, Institute of Ocean Sciences, 9860 West Saanich Road, P.O. Box 6000, Sidney, BC, Canada V8L 4B2 (Canada); Ross, Peter S., E-mail: peter.s.ross@dfo-mpo.gc.ca [University of Victoria, School of Earth and Ocean Sciences, 3800 Finnerty Road, Victoria, BC, Canada V8P 5C2 (Canada); Fisheries and Oceans Canada, Institute of Ocean Sciences, 9860 West Saanich Road, P.O. Box 6000, Sidney, BC, Canada V8L 4B2 (Canada); Dangerfield, Neil [Fisheries and Oceans Canada, Institute of Ocean Sciences, 9860 West Saanich Road, P.O. Box 6000, Sidney, BC, Canada V8L 4B2 (Canada); Palace, Vince P. [Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, MB, Canada R3T 2N6 (Canada); Whiticar, Michael [University of Victoria, School of Earth and Ocean Sciences, 3800 Finnerty Road, Victoria, BC, Canada V8P 5C2 (Canada); Loseto, Lisa L. [Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, MB, Canada R3T 2N6 (Canada)

    2013-10-15

    Highlights: •We examine the influence of biology, ecology and contaminant exposure on vitamin A and E profiles in Arctic beluga whales. •PCBs altered vitamin profiles after accounting for sex, age, condition and feeding ecology. •We propose a toxicity reference value for the disruption of vitamin A and E profiles in beluga of 1.6 mg/kg PCBs. •The use of vitamins as biomarkers of contaminant effects is contingent upon an understanding of wildlife biology. -- Abstract: We evaluated the utility of vitamin A and E profiles as biomarkers of contaminant exposure in beluga whales (Delphinapterus leucas; n = 66) harvested by the Inuvialuit in the Beaufort Sea. Blubber was an important repository for these vitamins, accounting for 76.8 ± 2.6% of the total body store of vitamin A, and 98.5 ± 0.4% of total vitamin E. While the free alcohol form of vitamin A (retinol) appeared highly regulated, the vitamin A esters were influenced by several biological factors including age, body condition and length. Vitamin E concentrations in liver and blubber were related to age, condition, length and feeding ecology, as described δ{sup 15}N and δ{sup 13}C. Despite the influence of these factors, collective results from univariate statistics, best fit multiple regressions, and principal component analysis (PCA) identified polychlorinated biphenyls (PCBs) as important determinants of vitamin concentrations and profiles in beluga tissues. Blubber PCB concentrations best explained variation of the first principal component in a PCA of hepatic vitamins (r{sup 2} = 0.13, p = 0.014), and regression models found that vitamin A concentrations were negatively correlated with PCB levels in liver (esters: r{sup 2} = 0.19, p = 0.001), but positively in plasma (retinol: r{sup 2} = 0.20, p = 0.06) and blubber (retinol: r{sup 2} = 0.22, p = 0.001, esters: r{sup 2} = 0.43, p < 0.001). Our analyses provide a basis to propose an integrated toxicity reference value for disruption of vitamin A and

  12. Vitamin A and E profiles as biomarkers of PCB exposure in beluga whales (Delphinapterus leucas) from the western Canadian Arctic

    International Nuclear Information System (INIS)

    Highlights: •We examine the influence of biology, ecology and contaminant exposure on vitamin A and E profiles in Arctic beluga whales. •PCBs altered vitamin profiles after accounting for sex, age, condition and feeding ecology. •We propose a toxicity reference value for the disruption of vitamin A and E profiles in beluga of 1.6 mg/kg PCBs. •The use of vitamins as biomarkers of contaminant effects is contingent upon an understanding of wildlife biology. -- Abstract: We evaluated the utility of vitamin A and E profiles as biomarkers of contaminant exposure in beluga whales (Delphinapterus leucas; n = 66) harvested by the Inuvialuit in the Beaufort Sea. Blubber was an important repository for these vitamins, accounting for 76.8 ± 2.6% of the total body store of vitamin A, and 98.5 ± 0.4% of total vitamin E. While the free alcohol form of vitamin A (retinol) appeared highly regulated, the vitamin A esters were influenced by several biological factors including age, body condition and length. Vitamin E concentrations in liver and blubber were related to age, condition, length and feeding ecology, as described δ15N and δ13C. Despite the influence of these factors, collective results from univariate statistics, best fit multiple regressions, and principal component analysis (PCA) identified polychlorinated biphenyls (PCBs) as important determinants of vitamin concentrations and profiles in beluga tissues. Blubber PCB concentrations best explained variation of the first principal component in a PCA of hepatic vitamins (r2 = 0.13, p = 0.014), and regression models found that vitamin A concentrations were negatively correlated with PCB levels in liver (esters: r2 = 0.19, p = 0.001), but positively in plasma (retinol: r2 = 0.20, p = 0.06) and blubber (retinol: r2 = 0.22, p = 0.001, esters: r2 = 0.43, p < 0.001). Our analyses provide a basis to propose an integrated toxicity reference value for disruption of vitamin A and E profiles in beluga of 1.6 mg/kg lw PCBs

  13. Investigating the design and application of a funnel and gate barrier for PCB remediation in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Kalinovich, I.; Rowe, R.K. [Queen' s Univ., Kingston, ON (Canada). Dept. of Civil Engineering]|[Royal Military Coll. of Canada, Kingston, ON (Canada); Rutter, A.; Poland, J. [Queen' s Univ., Kingston, ON (Canada). Dept. of Environmental Engineering; McWatters, R. [Queen' s Univ., Kingston, ON (Canada)

    2004-07-01

    A long-term remediation plan is underway at a former military radar base at Resolution Island, Nunavut to prevent the migration of soils contaminated with polychlorinated biphenyls (PCBs) from entering the drainage pathways of the island and flowing into the ocean. Migration pathways for PCBs include: leaching from soil; becoming mobilized via runoff; and, dispersed as an aerosol into the atmosphere. This study examined the feasibility of using geosynthetics as filters and sorbents in a funnel and gate barrier system. Preliminary results from a field trial were reported. The main concern was to determine how the geosynthetics will perform in the harsh Arctic conditions. In addition to field studies, laboratory studies examined the changes in permittivity in geosynthetics that have been exposed to ultraviolet (UV) and freeze-thaw conditions. Different geosynthetic materials, including filters and adsorbents, were also examined to determine if an isotherm can be established and used to evaluate sorption kinetics. The funnel and gate barrier system currently installed at the site is working as expected. The barrier system traps PCBs in a short period of time and the geosynthetic boom is an excellent adsorbent of PCBs. However, the permeability of the barrier materials seem to be affected by freeze-thaw and UV effects. 17 refs., 2 tabs., 1 fig.

  14. Current-use pesticides in seawater and their bioaccumulation in polar bear-ringed seal food chains of the Canadian Arctic.

    Science.gov (United States)

    Morris, Adam D; Muir, Derek C G; Solomon, Keith R; Letcher, Robert J; McKinney, Melissa A; Fisk, Aaron T; McMeans, Bailey C; Tomy, Gregg T; Teixeira, Camilla; Wang, Xiaowa; Duric, Mark

    2016-07-01

    The distribution of current-use pesticides (CUPs) in seawater and their trophodynamics were investigated in 3 Canadian Arctic marine food chains. The greatest ranges of dissolved-phase concentrations in seawater for each CUP were endosulfan sulfate (less than method detection limit (MDL) to 19 pg L(-1) ) > dacthal (0.76-15 pg L(-1) ) > chlorpyrifos (less than MDL to 8.1 pg L(-1) ) > pentachloronitrobenzene (less than MDL to 2.6 pg L(-1) ) > α-endosulfan (0.20-2.3 pg L(-1) ). Bioaccumulation factors (BAFs, water-respiring organisms) were greatest in plankton, including chlorothalonil (log BAF = 7.4 ± 7.1 L kg(-1) , mean ± standard error), chlorpyrifos (log BAF = 6.9 ± 6.7 L kg(-1) ), and α-endosulfan (log BAF = 6.5 ± 6.0 L kg(-1) ). The largest biomagnification factors (BMFs) were found for dacthal in the capelin:plankton trophic relationship (BMF = 13 ± 5.0) at Cumberland Sound (Nunvavut), and for β-endosulfan (BMF = 16 ± 4.9) and α-endosulfan (BMF = 9.3 ± 2.8) in the polar bear-ringed seal relationship at Barrow and Rae Strait (NU), respectively. Concentrations of endosulfan sulfate exhibited trophic magnification (increasing concentrations with increasing trophic level) in the poikilothermic portion of the food web (trophic magnification factor = 1.4), but all of the CUPs underwent trophic dilution in the marine mammal food web, despite some trophic level-specific biomagnification. Together, these observations are most likely indicative of metabolism of these CUPs in mammals. Environ Toxicol Chem 2016;35:1695-1707. © 2016 SETAC. PMID:27027986

  15. Heterotrophic microbial colonization of the interior of impact-shocked rocks from Haughton impact structure, Devon Island, Nunavut, Canadian High Arctic

    Science.gov (United States)

    Fike, David A.; Cockell, Charles; Pearce, David; Lee, Pascal

    2002-10-01

    The polar desert is one of the most extreme environments on Earth. Endolithic organisms can escape or mitigate the hazards of the polar desert by using the resources available in the interior of rocks. We examined endolithic communities within crystalline rocks that have undergone shock metamorphism as a result of an asteroid or comet impact. Specifically, we present a characterization of the heterotrophic endolithic community and its environment in the interior of impact-shocked gneisses and their host polymict breccia from the Haughton impact structure on Devon Island, Nunavut, Canadian High Arctic. Microbiological colonization of impact-shocked rocks is facilitated by impact-induced fissures and cavities, which occur throughout the samples, the walls of which are lined with high abundances of biologically important elements owing to the partial volatilization of minerals within the rock during the impact. 27 heterotrophic bacteria were isolated from these shocked rocks and were identified by 16S rDNA sequencing. The isolates from the shocked gneiss and the host breccia are similar to each other, and to other heterotrophic communities isolated from polar environments, suggesting that the interiors of the rocks are colonized by microorganisms from the surrounding country rocks and soils. Inductively coupled plasma atomic emission spectroscopy (ICP-AES), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis were used to identify the chemical composition of the shocked materials and to document the in situ growth of microbes in their interiors. The identification of these heterotrophic communities within impact-shocked crystalline rocks extends our knowledge of the habitable biosphere on Earth. The colonization of the interiors of these samples has astrobiological applications both for considering terrestrial, microbiological contamination of meteorites from the Antarctic ice sheet and for investigating possible habitats for microbial

  16. The 25 MW Super Near Boiling nuclear reactor (SNB25) for supplying co-generation energy to an Arctic Canadian Forces Base

    International Nuclear Information System (INIS)

    Nuclear energy represents a better alternative for the supply of heat and electricity to the Canadian Forces bases in the Arctic (CFS Alert and CFB Nanisivik). In this context, the Super Near-Boiling 25-MWth reactor (SNB25) has been designed as a small unpressurized LWR that displays inherent safety and is intended to run in automatic mode. The reactor employs TRISO fuel particles (20% enrichment) in zirconium-sheathed fuel rods, and is light water cooled and moderated with a normal output temperature is 95 o C at atmospheric pressure. Control is via 133 control rods and six adjustable radial reflector plates. The design work used the probabilistic simulation code MCNP 5 and the deterministic code WIMS-AECL Version 3.1, permitting a code-to-code comparison of the results. Inherent safety was confirmed and is mostly due to the large negative void reactivity coefficient of -5.17 mk per % void. A kinetic model that includes thermal-hydraulics calculations was developed to determine the reactor's behaviour in transient states, and the results further confirm the inherent safety. Large power excursions temperatures that could compromise structural integrity cannot be produced. If the coolant/moderator temperature exceeds the saturation temperature of 100 o C, the coolant begins to boil and the large negative void coefficient causes the reactor to become subcritical in 0.84 seconds. The SNB25 reactor's core life exceeds 12 years between refuellings. A group of 4 SNB25 reactors meets both the heating and electricity requirements of a base like CFB Nanisivik via a hot water network and through an organic Rankine cycle conversion plant. (author)

  17. Productivity, chlorophyll a, Photosynthetically Active Radiation (PAR) and other phytoplankton data from the Arctic Ocean, Bering Sea, Chukchi Sea, Beaufort Sea, East Siberian Sea, Kara Sea, Barents Sea, and Arctic Archipelago measured between 17 April, 1954 and 30 May, 2006 compiled as part of the Arctic System Science Primary Production (ARCSS-PP) observational synthesis project (NODC Accession 0063065)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Arctic Ocean primary production data were assembled from original input data archived in various international databases, provided by individual investigators or in...

  18. Prevalence of zoonotic anisakid nematodes in Inuit-harvested fish and mammals from the eastern Canadian Arctic.

    Science.gov (United States)

    Pufall, Erica L; Jones-Bitton, Andria; McEwen, Scott A; Brown, Tanya M; Edge, Victoria L; Rokicki, Jerzy; Karpiej, Katarzyna; Peregrine, Andrew S; Simard, Manon

    2012-11-01

    Human anisakidosis is a recognized Arctic zoonosis that is directly related to the consumption of traditional Inuit foods, particularly raw fish. The epidemiology of infections with the zoonotic anisakid nematodes Anisakis simplex and Pseudoterranova decipiens was investigated from August 2007 to July 2009 in Inuit-harvested fish and marine mammals from Inuit regions of Nunavik, Nunavut, and Nunatsiavut, Canada. Fish were tested for anisakid larvae using the pepsin-HCl digestion method, and the stomachs or stomach contents of beluga whales, walruses, and three seal species were examined for anisakids. Anisakids were found in seven of eight fish species, as well as in ringed seals (18.2%; 31/170), bearded seals (75.0%; 12/16), and beluga whales (78.9%; 15/19), but not walruses (0%; 0/15). In fish, the odds of being infected with A. simplex and/or P. decipiens was 68.6 (95% confidence interval, 11.6-627.7) times higher in marine fish than in anadromous fish, after adjusting for length of fish. Negative binomial models were created for animal species with large enough sample sizes and parasite prevalence estimates to assess risk factors associated with anisakid abundance. In seals, the only risk factor significantly associated with increasing anisakid abundance was increasing length (p whales, the only significant risk factor was year of capture (p = 0.03). In fish, length was the variable most commonly associated with increased anisakid larval abundance, with longer fish having significantly higher larval abundances than shorter fish of the same species. The presence of A. simplex and P. decipiens in bearded seals, ringed seals, and beluga whales from Inuit hunting grounds suggests that they likely act as definitive hosts for these parasites in these environments. With respect to zoonotic disease risk associated with Inuit country foods, among the species of fish examined, Atlantic tomcod, polar cod, and sculpins represented the greatest risk of foodborne disease

  19. Total mercury concentrations in anadromous Northern Dolly Varden from the northwestern Canadian Arctic: A historical baseline study

    Energy Technology Data Exchange (ETDEWEB)

    Tran, L., E-mail: l5tran@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Reist, J.D. [Fisheries and Oceans Canada, Winnipeg, Manitoba R3T 2N6 (Canada); Power, M., E-mail: m3power@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2015-03-15

    Previous research has documented the significance of total mercury (THg) as a northern contaminant in general and of fish in particular. While much research has been devoted to documenting both spatial and temporal changes in THg in consumed fish, little effort has been directed at understanding patterns of THg in Dolly Varden (Salvelinus malma), a prized subsistence species throughout the western North American Arctic. Here we report historical THg concentrations for anadromous Dolly Varden from 10 populations in the Yukon and Northwest Territories sampled across a range of latitudes (67–69°N) and longitudes (136–141°W) between the years 1988–91. Unadjusted mean THg concentrations ranged from 15 to 254 ng/g wet weight. Length-adjusted THg concentrations were significantly different among sites, but were not related to latitude or longitude. Within and among populations, THg was significantly related to fork-length, age, δ{sup 15}N, and δ{sup 13}C, with the variation in THg found among populations being best explained by size. The data serve as an important baseline against which future changes in THg levels in this important subsistence fishery may be compared to determine the significance of any observed trends. - Highlights: • THg were measured in Dolly Varden from the Yukon and Northwest Territories. • Length-adjusted THg concentrations were not related to latitude or longitude. • Among-population variation in THg was best explained by fork-length. • Length-adjusted THg concentrations were related to age, δ{sup 15}N, and δ{sup 13}C. • Mean THg were below Health Canada’s consumption guideline for commercial fish.

  20. Recent Trends in the Arctic Navigable Ice Season and Links to Atmospheric Circulation

    Science.gov (United States)

    Maslanik, J.; Drobot, S.

    2002-12-01

    One of the potential effects of Arctic climate warming is an increase in the navigable ice season, perhaps resulting in development of the Arctic as a major shipping route. The distance from western North American ports to Europe through the Northwest Passage (NWP) or the Northern Sea Route (NSR) is typically 20 to 60 percent shorter than travel through the Panama Canal, while travel between Europe and the Far East may be reduced by as much as three weeks compared to transport through the Suez Canal. An increase in the navigable ice season would also improve commercial opportunities within the Arctic region, such as mineral and oil exploration and tourism, which could potentially expand the economic base of Arctic residents and companies, but which would also have negative environmental impacts. Utilizing daily passive-microwave derived sea ice concentrations, trends and variability in the Arctic navigable ice season are examined from 1979 through 2001. Trend analyses suggest large increases in the length of the navigable ice season in the Kara and Barents seas, the Sea of Okhotsk, and the Beaufort Sea, with decreases in the length of the navigable ice season in the Bering Sea. Interannual variations in the navigable ice season largely are governed by fluctuations in low-frequency atmospheric circulation, although the specific annular modes affecting the length of the navigable ice season vary by region. In the Beaufort and East Siberian seas, variations in the North Atlantic Oscillation/Arctic Oscillation control the navigable ice season, while variations in the East Pacific anomaly play an important role in controlling the navigable ice season in the Kara and Barents seas. In Hudson Bay, the Canadian Arctic Archipelago, and Baffin Bay, interannual variations in the navigable ice season are strongly related to the Pacific Decadal Oscillation.

  1. A 50% increase in the amount of terrestrial particles delivered by the Mackenzie River into the Beaufort Sea (Canadian Arctic Ocean) over the last 10 years

    OpenAIRE

    Doxaran, D; Devred, E.; M. Babin

    2015-01-01

    Global warming has a significant impact at the regional scale on the Arctic Ocean and surrounding coastal zones (i.e., Alaska, Canada, Greenland, Norway and Russia). The recent increase in air temperature has resulted in increased precipitations along the drainage basins of Arctic Rivers. It has also directly impacted land and seawater temperatures with the consequence of melting the permafrost and sea-ice. An increase in freshwater discharge by main Arctic rivers has ...

  2. Methane cross-validation between three Fourier transform spectrometers: SCISAT ACE-FTS, GOSAT TANSO-FTS, and ground-based FTS measurements in the Canadian high Arctic

    Science.gov (United States)

    Holl, Gerrit; Walker, Kaley A.; Conway, Stephanie; Saitoh, Naoko; Boone, Chris D.; Strong, Kimberly; Drummond, James R.

    2016-05-01

    We present cross-validation of remote sensing measurements of methane profiles in the Canadian high Arctic. Accurate and precise measurements of methane are essential to understand quantitatively its role in the climate system and in global change. Here, we show a cross-validation between three data sets: two from spaceborne instruments and one from a ground-based instrument. All are Fourier transform spectrometers (FTSs). We consider the Canadian SCISAT Atmospheric Chemistry Experiment (ACE)-FTS, a solar occultation infrared spectrometer operating since 2004, and the thermal infrared band of the Japanese Greenhouse Gases Observing Satellite (GOSAT) Thermal And Near infrared Sensor for carbon Observation (TANSO)-FTS, a nadir/off-nadir scanning FTS instrument operating at solar and terrestrial infrared wavelengths, since 2009. The ground-based instrument is a Bruker 125HR Fourier transform infrared (FTIR) spectrometer, measuring mid-infrared solar absorption spectra at the Polar Environment Atmospheric Research Laboratory (PEARL) Ridge Laboratory at Eureka, Nunavut (80° N, 86° W) since 2006. For each pair of instruments, measurements are collocated within 500 km and 24 h. An additional collocation criterion based on potential vorticity values was found not to significantly affect differences between measurements. Profiles are regridded to a common vertical grid for each comparison set. To account for differing vertical resolutions, ACE-FTS measurements are smoothed to the resolution of either PEARL-FTS or TANSO-FTS, and PEARL-FTS measurements are smoothed to the TANSO-FTS resolution. Differences for each pair are examined in terms of profile and partial columns. During the period considered, the number of collocations for each pair is large enough to obtain a good sample size (from several hundred to tens of thousands depending on pair and configuration). Considering full profiles, the degrees of freedom for signal (DOFS) are between 0.2 and 0.7 for TANSO-FTS and

  3. Reading the archipelago

    Directory of Open Access Journals (Sweden)

    Chris Bongie

    1999-01-01

    Full Text Available [First paragraph] A History of Literature in the Caribbean, Volume 3: Cross-Cultural Studies. JAMES A. ARNOLD (ed.. Philadelphia: John Benjamins, 1997. xvii + 399 pp. (Cloth US$ 120.00 The Other America: Caribbean Literature in a New World Context. J. MICHAEL DASH. Charlottesville: University of Virginia Press, 1998. xii + 197 pp. (Cloth US$ 42.50, Paper US$ 18.50 In his most recent theoretical work, Traite du Tout-Monde, Edouard Glissant stresses the virtues of what he calls "archipelagic thinking." "The entire world is becoming an archipelago," he asserts (1997:194, and for this reason we need to distance ourselves from both insular and continental ways of thinking if we are to register the complexities of that global creolization process. The archipelago is situated between the solitary confines of the islands that constitute it and the expansive territory of the mainland toward which it points, relating the one to the other while retaining its own indeterminately distinct identity. For Glissant, actual archipelagos such as the Caribbean are exemplary sites for understanding the complex new relations that ambivalently and chaotically join together all the hitherto unconnected parts of the world. As a consequence of this, the need for understanding the Caribbean as an archipelago becomes ever more pressing: the Caribbean must be considered in its archipelagic totality, as a region that can only be adequately understood through comparative, cross-cultural analysis focusing less on its discrete parts than on the way these parts exist in relation with and to one another.

  4. The Eocene Eurekan deformation in the Arctic - architecture and kinematics of a strange foldbelt

    Science.gov (United States)

    Piepjohn, Karsten; von Gosen, Werner; Tessensohn, Franz; Reinhardt, Lutz

    2016-04-01

    The polyphase Paleogene Eurekan deformational history in the Arctic represents a complex sequence of successive tectonic stages, which produced a number of intra-continental deformation zones with changing, sometimes opposing, lateral, oblique, and convergent kinematics along the involved plate boundaries in the Canadian Arctic Archipelago, North Greenland, and Svalbard. The Eurekan deformation is characterized by different structural styles with the development of fold-and-thrust belts in Spitsbergen and in the Canadian Arctic, distinct compressional thrust zones in North Greenland and Ellesmere Island, large systems of strike-slip fault zones in Spitsbergen, Northeast Greenland and Ellesmere Island, and the combination of both compressional and lateral fault zones in northern Ellesmere Island. Eurekan tectonism was caused by the opening and continuous evolution of the Eurasian Basin in connection with the development of the Labrador Sea/Baffin Bay and the North Atlantic Ocean spreading ridges. The following tectonic stages can be distinguished which are responsible for the Eurekan deformation: - Pre-Eurekan Stage: sea-floor spreading in Labrador Sea and rifting in Baffin Bay, Norwegian/Greenland seas and the Eurasian Basin (100-53 Ma). - Eurekan Stage 1: sea-floor spreading and transform faults around Greenland resulted in a NE-directed movement with (a) sinistral transpression along Nares Strait and probably sinistral motion along the fault zones parallel to the north margin of Ellesmere Island, and (b) compression at the West Spitsbergen Fold-and-Thrust Belt (53-47 Ma). - Eurekan Stage 2: NW-wards directed movement of Greenland with (a) compression along Nares Strait and parts of Ellesmere Island combined with dextral motions parallel to the continental margin of the Canadian Arctic Archipelago (b) and dextral strike-slip tectonics along Fram Strait (47-34 Ma). - Post-Eurekan Stage: termination of sea-floor spreading in Labrador Sea/Baffin Bay and separation of

  5. Carboniferous non-marine source rocks from Spitsbergen and Bjoernoeya: comparison with the Western Arctic

    Energy Technology Data Exchange (ETDEWEB)

    van Koeverden, J.H.; Karlsen, D.A.; Backer-Owe, K. [University of Oslo, Oslo (Norway). Dept. of Geoscience

    2011-01-15

    In this paper, we demonstrate that Carboniferous coaly and lacustrine strata have significant liquid hydrocarbon potential in an area extending from the Norwegian Barents Sea in the east to the Canadian Arctic in the west. Organic geochemical analyses were conducted on seven coals and coaly shales from the islands of Spitsbergen (Svalbard archipelago) and Bjpernoeya (Norwegian Barents Sea). The results were interpreted in the context of published data from the two areas, and of time-equivalent non-marine successions on the Finnmark Platform (Norwegian Barents Sea), East Greenland, and the Sverdrup Basin (Canadian Arctic). In each of these areas, a warm and humid climate, together with the onset of rifting on the northern Pangea margin, facilitated the deposition and preservation of organic-rich non-marine sediments on a regional scale. All of the sediments have an elevated content of liptinitic macerals, dominated by alginite or sporinite. In the studied areas, the prolific younger source rocks which may be common in adjacent regions are often immature or absent. The identification of Carboniferous terrestrial strata with source rock potential may therefore enhance the petroleum potential of the studied regions.

  6. Past Arctic aliens have passed away, current ones may stay

    OpenAIRE

    2015-01-01

    Increased human activity and climate change are expected to increase the numbers and impact of alien species in the Arctic, but knowledge of alien species is poor in most Arctic regions. Through field investigations over the last 10 years, and review of alien vascular plant records for the high Arctic Archipelago Svalbard over the past 130 years, we explored long term trends in persistence and phenology. In total, 448 observations of 105 taxa have been recorded from 28 sites. Recent surveys a...

  7. Arctic Landfast Sea Ice 1953-1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The files in this data set contain landfast sea ice data (monthly means) gathered from both Russian Arctic and Antarctic Research Institute (AARI) and Canadian Ice...

  8. A 50% increase in the amount of terrestrial particles delivered by the Mackenzie River into the Beaufort Sea (Canadian Arctic Ocean over the last 10 years

    Directory of Open Access Journals (Sweden)

    D. Doxaran

    2015-01-01

    Full Text Available Global warming has a significant impact at the regional scale on the Arctic Ocean and surrounding coastal zones (i.e., Alaska, Canada, Greenland, Norway and Russia. The recent increase in air temperature has resulted in increased precipitations along the drainage basins of Arctic Rivers. It has also directly impacted land and seawater temperatures with the consequence of melting the permafrost and sea-ice. An increase in freshwater discharge by main Arctic rivers has been clearly identified in time series of field observations. The freshwater discharge of the Mackenzie River has increased by 25% since 2003. This may have increased the mobilization and transport of various dissolved and particulate substances, including organic carbon, as well as their export to the ocean. The release from land to the ocean of such organic material, which was sequestered as frozen since the last glacial maximum, may significantly impact the Arctic Ocean carbon cycle as well as marine ecosystems. In this study we use 11 years of ocean-colour satellite data and field observations collected in 2009 to estimate the amount of terrestrial suspended solids and particulate organic carbon delivered by the Mackenzie River into the Beaufort Sea (Arctic Ocean. Our results show that during the summer period the concentration of suspended solids at the river mouth, in the delta zone and in the river plume has increased by 46, 71 and 33%, respectively, since 2003. Combined with the variations observed in the freshwater discharge, this corresponds to a more than 50% increase in the particulate (terrestrial suspended particles and organic carbon export from the Mackenzie River into the Beaufort Sea.

  9. A 50 % increase in the mass of terrestrial particles delivered by the Mackenzie River into the Beaufort Sea (Canadian Arctic Ocean) over the last 10 years

    Science.gov (United States)

    Doxaran, D.; Devred, E.; Babin, M.

    2015-06-01

    Global warming has a significant impact on the regional scale on the Arctic Ocean and surrounding coastal zones (i.e., Alaska, Canada, Greenland, Norway and Russia). The recent increase in air temperature has resulted in increased precipitation along the drainage basins of Arctic rivers. It has also directly impacted land and seawater temperatures with the consequence of melting permafrost and sea ice. An increase in freshwater discharge by main Arctic rivers has been clearly identified in time series of field observations. The freshwater discharge of the Mackenzie River has increased by 25% since 2003. This may have increased the mobilization and transport of various dissolved and particulate substances, including organic carbon, as well as their export to the ocean. The release from land to the ocean of such organic material, which has been sequestered in a frozen state since the Last Glacial Maximum, may significantly impact the Arctic Ocean carbon cycle as well as marine ecosystems. In this study we use 11 years of ocean color satellite data and field observations collected in 2009 to estimate the mass of terrestrial suspended solids and particulate organic carbon delivered by the Mackenzie River into the Beaufort Sea (Arctic Ocean). Our results show that during the summer period, the concentration of suspended solids at the river mouth, in the delta zone and in the river plume has increased by 46, 71 and 33%, respectively, since 2003. Combined with the variations observed in the freshwater discharge, this corresponds to a more than 50% increase in the particulate (terrestrial suspended particles and organic carbon) export from the Mackenzie River into the Beaufort Sea.

  10. A 50% increase in the amount of terrestrial particles delivered by the Mackenzie River into the Beaufort Sea (Canadian Arctic Ocean) over the last 10 years

    Science.gov (United States)

    Doxaran, D.; Devred, E.; Babin, M.

    2015-01-01

    Global warming has a significant impact at the regional scale on the Arctic Ocean and surrounding coastal zones (i.e., Alaska, Canada, Greenland, Norway and Russia). The recent increase in air temperature has resulted in increased precipitations along the drainage basins of Arctic Rivers. It has also directly impacted land and seawater temperatures with the consequence of melting the permafrost and sea-ice. An increase in freshwater discharge by main Arctic rivers has been clearly identified in time series of field observations. The freshwater discharge of the Mackenzie River has increased by 25% since 2003. This may have increased the mobilization and transport of various dissolved and particulate substances, including organic carbon, as well as their export to the ocean. The release from land to the ocean of such organic material, which was sequestered as frozen since the last glacial maximum, may significantly impact the Arctic Ocean carbon cycle as well as marine ecosystems. In this study we use 11 years of ocean-colour satellite data and field observations collected in 2009 to estimate the amount of terrestrial suspended solids and particulate organic carbon delivered by the Mackenzie River into the Beaufort Sea (Arctic Ocean). Our results show that during the summer period the concentration of suspended solids at the river mouth, in the delta zone and in the river plume has increased by 46, 71 and 33%, respectively, since 2003. Combined with the variations observed in the freshwater discharge, this corresponds to a more than 50% increase in the particulate (terrestrial suspended particles and organic carbon) export from the Mackenzie River into the Beaufort Sea.

  11. Characterizing Arctic sea ice topography using high-resolution IceBridge data

    Science.gov (United States)

    Petty, Alek A.; Tsamados, Michel C.; Kurtz, Nathan T.; Farrell, Sinead L.; Newman, Thomas; Harbeck, Jeremy P.; Feltham, Daniel L.; Richter-Menge, Jackie A.

    2016-05-01

    We present an analysis of Arctic sea ice topography using high-resolution, three-dimensional surface elevation data from the Airborne Topographic Mapper, flown as part of NASA's Operation IceBridge mission. Surface features in the sea ice cover are detected using a newly developed surface feature picking algorithm. We derive information regarding the height, volume and geometry of surface features from 2009 to 2014 within the Beaufort/Chukchi and Central Arctic regions. The results are delineated by ice type to estimate the topographic variability across first-year and multi-year ice regimes. The results demonstrate that Arctic sea ice topography exhibits significant spatial variability, mainly driven by the increased surface feature height and volume (per unit area) of the multi-year ice that dominates the Central Arctic region. The multi-year ice topography exhibits greater interannual variability compared to the first-year ice regimes, which dominates the total ice topography variability across both regions. The ice topography also shows a clear coastal dependency, with the feature height and volume increasing as a function of proximity to the nearest coastline, especially north of Greenland and the Canadian Archipelago. A strong correlation between ice topography and ice thickness (from the IceBridge sea ice product) is found, using a square-root relationship. The results allude to the importance of ice deformation variability in the total sea ice mass balance, and provide crucial information regarding the tail of the ice thickness distribution across the western Arctic. Future research priorities associated with this new data set are presented and discussed, especially in relation to calculations of atmospheric form drag.

  12. Circumpolar Arctic greening: Relationships to summer sea-ice concentrations, land temperatures and disturbance regimes

    Science.gov (United States)

    Walker, D. A.; Bhatt, U. S.; Epstein, H. E.; Raynolds, M. K.; Frost, G. V.; Leibman, M. O.; Khomutov, A.; Jia, G.; Comiso, J. C.; Pinzon, J. E.; Tucker, C. J.; Webber, P. J.; Tweedie, C. E.

    2009-12-01

    The global distribution of Arctic tundra vegetation is closely tied to the presence of summer sea ice. Models predict that the reduction of sea ice will cause large changes to summer land-surface temperatures. Warming combined with increased natural and anthropogenic disturbance are expected to greatly increase arctic tundra productivity. To examine where tundra productivity is changing most rapidly, we studied 1982-2008 trends of sea-ice concentrations, summer warmth index (SWI) and the annual Maximum Normalized Difference Vegetation Index (MaxNDVI). We summarize the results according to the tundra adjacent to 14 Arctic seas. Sea-ice concentrations have declined and summer land temperatures have increased in all parts of the Arctic coast. The overall percentage increase in Arctic MaxNDVI was +7%. The trend was much greater in North America (+11%) than in Eurasia (+4%). Large percentage increases of MaxNDVI occurred inland from Davis Straight (+20%), Baffin Bay (+18%), Canadian Archipelago (+14%), Beaufort Sea (+12%), and Laptev Sea (+8%). Declines occurred in the W. Chukchi (-6%) and E. Bering (-5%) seas. The changes in NDVI are strongly correlated to changes in summer ground temperatures. Two examples from a 900-km north-south Arctic transect in Russia and long-term observations at a High Arctic site in Canada provide insights to where the changes in productivity are occurring most rapidly. At tree line near Kharp in northwest Siberia, alder shrubs are expanding vigorously in fire-disturbed areas; seedling establishment is occurring primarily in areas with disturbed mineral soils, particularly nonsorted circles. In the Low Arctic tundra areas of the central Yamal Peninsula greening is concentrated in riparian areas and upland landslides associated with degrading massive ground ice, where low-willow shrublands replace the zonal sedge, dwarf-shrub tundra growing on nutrient-poor sands. In polar desert landscapes near the Barnes Ice Cap, Baffin Island, Canada

  13. The effect of tides on sea ice, temperature and salinity fields in the Arctic Ocean on multi-decadal scales.

    Science.gov (United States)

    Luneva, Maria; Harle, James; Holt, Jason; Aksenov, Yevgeny

    2014-05-01

    The effects of tides on the hydrographical fields and sea-ice on multi-decadal timescales (from 1978-2007) has been examined using a newly developed Arctic Ocean NEMO-shelf-ice coupled model of moderate (10-15km) resolution, which explicitly simulates tides and processes in the benthic boundary layer. The model realistically reproduces the tides, which can be extremely strong on the Arctic shelf, with amplitudes reaching 4.4m in the Hudson Strait, 2-3m in the White Sea and above 1m in the Canadian Archipelago. It also accurately predicts the sea ice volume trends over this period, when compared with PIOMAS results, and demonstrates a stronger reduction in ice volume (by ~15%) and extent (by ~5%) in comparison with simulations without tides. By including tides in the Arctic simulation we find: (i) a decrease in ice thickness from 0.1 to 1m in Central Arctic, and up to 2m in the Canadian Archipelago; (ii) ice melting and thinning is accompanied by an increase in average surface salinity by 2PSU and changes of river freshwater pathways; (iii) cooling of the upper 300m of the Arctic Ocean in comparison with non-tidal simulations. We hypothesize that tidal mixing and advection support the supply of heat from warm Atlantic waters through the strongly stratified halocline layer. It has been found that tidal effects on the water mass structure are regionally localised, but subsequent can be transported across the entire basin. We discuss the following physical mechanisms for tidal influence: (a) increased vertical mixing near the bottom layer and on the ice-ocean interface; (b) opening and closing of leads in the sea ice in summer time altering the solar radiation flux to water below, thus affecting the ocean heat content and amount of ice melt ; (c) opening and closing of leads in the sea ice during winter leading to an increase the heat loss from the ocean to atmosphere, with subsequent ice production and brine rejection; (d) increased mixing in the pycnocline and at the

  14. Arctic Environmental Data Directory

    International Nuclear Information System (INIS)

    The Arctic Environmental Data Directory (AEDD) is being developed in cooperation with the US Global Change Research Plan. The AEDD Working Group, with members from US and Canadian agencies and academia, have described more than 300 Arctic data sets in a subset of an online data directory maintained by the US Geological Survey (USGS), ESDD (the Earth Science Data Directory). Through various links known as the Inter-operable Directory, the contents of AEDD are made available to scientists who use the NASA, NOAA, NSF and USGS data directories. Thus, scientists studying global change have access to Arctic data, and scientists studying the Arctic have access to global change data. The AEDD Working Group has sponsored development of a prototype Compact Disc Read Only Memory (CDROM) containing the indexed contents of the AEDD. Named Arctic Data Interactive (ADI), the disc was developed for use on Apple Macintosh and IBM PC-compatible computers, and uses a graphical and intuitive hypermedia user interface. The disc also contains portions of an Arctic Bibliography prepared in concert with the Polar Library Colloquy, sample full-text articles with illustrations, and selected data sets, including tabular data, text, and imagery. The ADI prototype is prepared as a model for organizing, presenting and distributing large quantities of Arctic and global change data and information to the science community. It is intended to be the first series of CDROMs with a consistent graphic design and user interface to place Arctic data and information on the desktop. The data are packaged with a powerful set of intuitive tools to navigate through and preview data sets from many disciplines and institutions. AEDD and ADI are sponsored by the Inter-agency Arctic Research Policy Committee and the Inter-agency Working Group on Data Management for Global Change, with guidance from the US Arctic Research Commission

  15. Baseline monitoring of the Western Arctic Ocean estimates 20% of the Canadian Basin surface waters are undersaturated with respect to aragonite

    Science.gov (United States)

    Robbins, Lisa L.; Wynn, Jonathan G.; Lisle, John T.; Yates, Kimberly K.; Knorr, Paul O.; Byrne, Robert H.; Liu, Xuewu; Patsavas, Mark C.; Azetsu-Scott, Kumiko; Takahashi, Taro

    2013-01-01

    Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification. Here, based on more than 34,000 data records collected in 2010 and 2011, we establish a baseline of inorganic carbon data (pH, total alkalinity, dissolved inorganic carbon, partial pressure of carbon dioxide, and aragonite saturation index) for the western Arctic Ocean. This data set documents aragonite undersaturation in ~20% of the surface waters of the combined Canada and Makarov basins, an area characterized by recent acceleration of sea ice loss. Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation. These data link the Arctic Ocean’s largest area of aragonite undersaturation to sea ice melt and atmospheric CO2 absorption in areas of low buffering capacity. Some relatively supersaturated areas can be linked to localized biological activity. Collectively, these observations can be used to project trends of ocean acidification in higher latitude marine surface waters where inorganic carbon chemistry is largely influenced by sea ice meltwater.

  16. Ammonia in the summertime Arctic marine boundary layer: sources, sinks, and implications

    Science.gov (United States)

    Wentworth, Gregory R.; Murphy, Jennifer G.; Croft, Betty; Martin, Randall V.; Pierce, Jeffrey R.; Côté, Jean-Sébastien; Courchesne, Isabelle; Tremblay, Jean-Éric; Gagnon, Jonathan; Thomas, Jennie L.; Sharma, Sangeeta; Toom-Sauntry, Desiree; Chivulescu, Alina; Levasseur, Maurice; Abbatt, Jonathan P. D.

    2016-02-01

    Continuous hourly measurements of gas-phase ammonia (NH3(g)) were taken from 13 July to 7 August 2014 on a research cruise throughout Baffin Bay and the eastern Canadian Arctic Archipelago. Concentrations ranged from 30 to 650 ng m-3 (40-870 pptv) with the highest values recorded in Lancaster Sound (74°13' N, 84°00' W). Simultaneous measurements of total ammonium ([NHx]), pH and temperature in the ocean and in melt ponds were used to compute the compensation point (χ), which is the ambient NH3(g) concentration at which surface-air fluxes change direction. Ambient NH3(g) was usually several orders of magnitude larger than both χocean and χMP (transport model was employed to examine the impact of NH3(g) emissions from seabird guano on boundary-layer composition and nss-SO42- neutralization. A GEOS-Chem simulation without seabird emissions underestimated boundary layer NH3(g) by several orders of magnitude and yielded highly acidic aerosol. A simulation that included seabird NH3 emissions was in better agreement with observations for both NH3(g) concentrations and nss-SO42- neutralization. This is strong evidence that seabird colonies are significant sources of NH3 in the summertime Arctic, and are ubiquitous enough to impact atmospheric composition across the entire Baffin Bay region. Large wildfires in the Northwest Territories were likely an important source of NH3, but their influence was probably limited to the Central Canadian Arctic. Implications of seabird-derived N-deposition to terrestrial and aquatic ecosystems are also discussed.

  17. Geochemical and Sr-Nd isotope variations within Cretaceous continental flood-basalt suites of the Canadian High Arctic, with a focus on the Hassel Formation basalts of northeast Ellesmere Island

    Science.gov (United States)

    Estrada, Solveig

    2015-11-01

    Early- to mid-Cretaceous flood-basalt suites of the northeast Canadian High Arctic assigned to a High Arctic Large Igneous Province (HALIP) were studied for their whole-rock geochemistry and Sr-Nd isotopes. Data from basalt flows within the upper Albian to lower Cenomanian Hassel Formation of northeast Ellesmere Island are compared with former published data and new inductively coupled plasma mass spectrometry data of the stratigraphic equivalent Strand Fiord basalts and the older, late Hauterivian to Aptian Isachsen basalts from Axel Heiberg Island. The transitional to mildly alkaline aphyric Hassel basalts, with ocean island basalt (OIB)-like geochemical signatures in parts, have an Ar-Ar whole-rock age of on average 96.4 ± 1.6 Ma. They represent two geochemically different flow units without a fractional crystallization relationship: the high-phosphorous (HP) and low-phosphorous (LP) basalts. The Hassel HP basalts differ from the LP basalts by additionally higher Ba, K, Rb, Th and LREE contents, a pronounced positive Eu anomaly (Eu/Eu* = 1.74-1.76), as well as lower Ta, Nb, Zr and Hf concentrations. The Nd and Sr isotope ratios of the Hassel HP basalts [ ɛ Nd( t) of -1.3 to -1.4, 87Sr/86Sr( t) of 0.70706-0.70707] and the LP basalts [ ɛ Nd( t) of 4.5-4.9, 87Sr/86Sr( t) of 0.7038-0.7040] indicate an origin from different mantle sources. The geochemically similar tholeiitic Isachsen (ca. 130-113 Ma) and Strand Fiord basalts (ca. 105-95 Ma) are also incompatible element enriched relative to the primitive mantle, however, with negative Sr-P anomalies as well as partially negative K, Ta and Nb anomalies. In terms of incompatible element ratios (Zr/Nb, Nb/Th), several mantle components are involved in the formation of the flood-basalt suites: a component with primitive mantle composition, an OIB-like component (probably subducted and recycled oceanic crust) and an enriched lithospheric component. The latter component, probably metasomatized subcontinental

  18. Deciphering the Arctic's depths : application of latest in exploration technologies yielding new insights into undersea geology

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.

    2009-12-15

    As new technologies become available, exploration in the Arctic is expanding into largely unexplored basins. This article highlighted many recent exploration efforts in areas such as the Beaufort Sea, the Chukchi Sea, Alaska, Mackenzie Delta, the Northwest Passage through the Canadian Arctic archipelago, and the waters surrounding northeast Greenland. It listed the companies who have sought exploration leases and summarized their activities, which include seismic surveys that provide new insights on a basin-wide scale. Houston-based ION Geophysical Corporation has undertaken 3 major seismic surveys known as the SPAN projects. These are geologically inspired, basin-scale, ultra-deep seismic programs that allow exploration companies to evaluate the geologic evolution, deep basin architecture and depositional and structural histories of entire petroleum systems across a region. Their purpose is to determine where source rocks are most prevalent, where sediment fairways are located and where the most promising migration paths from source to reservoir exist. ION has approximately 250,000 line kilometres of SPAN data acquired around the globe. Several of the world's largest energy companies agreed to underwrite the basin-scale imaging project, recognizing the potential in the Arctic, which contains nearly 25 per cent of the world's undiscovered oil and gas resources according to the United States Geological Survey. 1 ref., 5 figs.

  19. Simulations of 20th and 21st century Arctic cloud amount in the global climate models assessed in the IPCC AR4

    Science.gov (United States)

    Vavrus, Steve; Waliser, Duane; Schweiger, Axel; Francis, Jennifer

    2009-12-01

    Simulations of late 20th and 21st century Arctic cloud amount from 20 global climate models (GCMs) in the Coupled Model Intercomparison Project phase 3 (CMIP3) dataset are synthesized and assessed. Under recent climatic conditions, GCMs realistically simulate the spatial distribution of Arctic clouds, the magnitude of cloudiness during the warmest seasons (summer-autumn), and the prevalence of low clouds as the predominant type. The greatest intermodel spread and most pronounced model error of excessive cloudiness coincides with the coldest seasons (winter-spring) and locations (perennial ice pack, Greenland, and the Canadian Archipelago). Under greenhouse forcing (SRES A1B emissions scenario) the Arctic is expected to become cloudier, especially during autumn and over sea ice, in tandem with cloud decreases in middle latitudes. Projected cloud changes for the late 21st century depend strongly on the simulated modern (late 20th century) annual cycle of Arctic cloud amount: GCMs that correctly simulate more clouds during summer than winter at present also tend to simulate more clouds in the future. The simulated Arctic cloud changes display a tripole structure aloft, with largest increases concentrated at low levels (below 700 hPa) and high levels (above 400 hPa) but little change in the middle troposphere. The changes in cloud radiative forcing suggest that the cloud changes are a positive feedback annually but negative during summer. Of potential explanations for the simulated Arctic cloud response, local evaporation is the leading candidate based on its high correlation with the cloud changes. The polar cloud changes are also significantly correlated with model resolution: GCMs with higher spatial resolution tend to produce larger future cloud increases.

  20. Simulations of 20th and 21st century Arctic cloud amount in the global climate models assessed in the IPCC AR4

    Energy Technology Data Exchange (ETDEWEB)

    Vavrus, Steve [University of Wisconsin-Madison, Center for Climatic Research, Madison, WI (United States); Waliser, Duane [Jet Propulsion Laboratory, MS 183-501, Water and Carbon Cycles Group, Pasadena, CA (United States); Schweiger, Axel [University of Washington, Polar Science Center, Seattle, WA (United States); Francis, Jennifer [Rutgers University, J. J. Howard Marine Laboratory, Highlands, NJ (United States)

    2009-12-15

    Simulations of late 20th and 21st century Arctic cloud amount from 20 global climate models (GCMs) in the Coupled Model Intercomparison Project phase 3 (CMIP3) dataset are synthesized and assessed. Under recent climatic conditions, GCMs realistically simulate the spatial distribution of Arctic clouds, the magnitude of cloudiness during the warmest seasons (summer-autumn), and the prevalence of low clouds as the predominant type. The greatest intermodel spread and most pronounced model error of excessive cloudiness coincides with the coldest seasons (winter-spring) and locations (perennial ice pack, Greenland, and the Canadian Archipelago). Under greenhouse forcing (SRES A1B emissions scenario) the Arctic is expected to become cloudier, especially during autumn and over sea ice, in tandem with cloud decreases in middle latitudes. Projected cloud changes for the late 21st century depend strongly on the simulated modern (late 20th century) annual cycle of Arctic cloud amount: GCMs that correctly simulate more clouds during summer than winter at present also tend to simulate more clouds in the future. The simulated Arctic cloud changes display a tripole structure aloft, with largest increases concentrated at low levels (below 700 hPa) and high levels (above 400 hPa) but little change in the middle troposphere. The changes in cloud radiative forcing suggest that the cloud changes are a positive feedback annually but negative during summer. Of potential explanations for the simulated Arctic cloud response, local evaporation is the leading candidate based on its high correlation with the cloud changes. The polar cloud changes are also significantly correlated with model resolution: GCMs with higher spatial resolution tend to produce larger future cloud increases. (orig.)

  1. Enantioselective bioaccumulation of hexabromocyclododecane and congener-specific accumulation of brominated diphenyl ethers in an eastern Canadian Arctic marine food web.

    Science.gov (United States)

    Tomy, Gregg T; Pleskach, Kerri; Oswald, Tyler; Halldorson, Thor; Helm, Paul A; MacInnis, Gordia; Marvin, Chris H

    2008-05-15

    The extent of trophic transfer of the three diastereoisomers of hexabromocyclododecane (HBCD) and seven brominated diphenyl ether (BDE) congeners was examined in components of an Arctic marine food web from eastern Canada. Alpha and gamma-HBCD diastereoisomers were detected in all species and total (sigma) HBCD concentrations ranged from 0.6 +/- 0.2 pg/g (geometric mean +/- 1 x standard error (SE), lipid weight (lw)) in arctic cod to 3.9 +/- 0.9 ng/g (lw) in narwhal. beta-HBCD was below method detection limits in all the samples. Mean sigmaBDE (sum of seven congeners) concentrations ranged from 0.4 +/- 0.2 ng/g (lw) in walrus to 73 +/- 10 ng/g (lw) in zooplankton. The relative trophic status of biota was determined by nitrogen stable isotopes (delta15N), and results indicated clear differences in HBCD isomer and BDE congener profiles with trophic level (TL). Trophic magnification was observed for the alpha-diastereoisomer and BDE-47 as concentrations increased with increasing TL in the food web, whereas there was trophic dilution of gamma-HBCD and BDE-209 through the food web. Only the (-)alpha-enantiomer showed a strong positive relationship between concentration and TL (p trophic magnification factor (TMF) value of 2.2. A small but significant increase in the enantiomeric fraction value of the alpha-enantiomers with TL was also observed (r2 = 0.22, p < 0.005), implying that there is an overall preferential enrichment of the (-)alpha-enantiomer relative to the (+)alpha-enantiomer likely due to the greater bioaccumulation potential of the (-)alpha-enantiomer and/or to the greater susceptibility of the (+)alpha-enantiomer to metabolism. PMID:18546701

  2. Assessment of neurotoxic effects of mercury in beluga whales (Delphinapterus leucas), ringed seals (Pusa hispida), and polar bears (Ursus maritimus) from the Canadian Arctic.

    Science.gov (United States)

    Krey, Anke; Ostertag, Sonja K; Chan, Hing Man

    2015-03-15

    Marine mammals are indicator species of the Arctic ecosystem and an integral component of the traditional Inuit diet. The potential neurotoxic effects of increased mercury (Hg) in beluga whales (Delphinapterus leucas), ringed seals (Pusa hispida), and polar bears (Ursus maritimus) are not clear. We assessed the risk of Hg-associated neurotoxicity to these species by comparing their brain Hg concentrations with threshold concentrations for toxic endpoints detected in laboratory animals and field observations: clinical symptoms (>6.75 mg/kg wet weight (ww)), neuropathological signs (>4 mg/kg ww), neurochemical changes (>0.4 mg/kg ww), and neurobehavioral changes (>0.1mg/kg ww). The total Hg (THg) concentrations in the cerebellum and frontal lobe of ringed seals and polar bears were 3mg/kg ww. Our results suggest that brain THg levels in polar bears are below levels that induce neurobehavioral effects as reported in the literature, while THg concentrations in ringed seals are within the range that elicit neurobehavioral effects and individual ringed seals exceed the threshold for neurochemical changes. The relatively high THg concentration in beluga whales exceeds all of the neurotoxicity thresholds assessed. High brain selenium (Se):Hg molar ratios were observed in all three species, suggesting that Se could protect the animals from Hg-associated neurotoxicity. This assessment was limited by several factors that influence neurotoxic effects in animals, including: animal species; form of Hg in the brain; and interactions with modifiers of Hg-associated toxicity, such as Se. Comparing brain Hg concentrations in wildlife with concentrations of appropriate laboratory studies can be used as a tool for risk characterization of the neurotoxic effects of Hg in Arctic marine mammals. PMID:24958011

  3. Velocity models and images using full waveform inversion and reverse time migration for the offshore permafrost in the Canadian shelf of Beaufort Sea, Arctic

    Science.gov (United States)

    Kang, S. G.; Hong, J. K.; Jin, Y. K.; Kim, S.; Kim, Y. G.; Dallimore, S.; Riedel, M.; Shin, C.

    2015-12-01

    During Expedition ARA05C (from Aug 26 to Sep 19, 2014) on the Korean icebreaker RV ARAON, the multi-channel seismic (MCS) data were acquired on the outer shelf and slope of the Canadian Beaufort Sea to investigate distribution and internal geological structures of the offshore ice-bonded permafrost and gas hydrates, totaling 998 km L-km with 19,962 shots. The MCS data were recorded using a 1500 m long solid-type streamer with 120 channels. Shot and group spacing were 50 m and 12.5 m, respectively. Most MCS survey lines were designed perpendicular and parallel to the strike of the shelf break. Ice-bonded permafrost or ice-bearing sediments are widely distributed under the Beaufort Sea shelf, which have formed during periods of lower sea level when portions of the shelf less than ~100m water depth were an emergent coastal plain exposed to very cold surface. The seismic P-wave velocity is an important geophysical parameter for identifying the distribution of ice-bonded permafrost with high velocity in this area. Recently, full waveform inversion (FWI) and reverse time migration (RTM) are commonly used to delineate detailed seismic velocity information and seismic image of geological structures. FWI is a data fitting procedure based on wave field modeling and numerical analysis to extract quantitative geophysical parameters such as P-, S-wave velocities and density from seismic data. RTM based on 2-way wave equation is a useful technique to construct accurate seismic image with amplitude preserving of field data. In this study, we suggest two-dimensional P-wave velocity model (Figure.1) using the FWI algorithm to delineate the top and bottom boundaries of ice-bonded permafrost in the Canadian shelf of Beaufort Sea. In addition, we construct amplitude preserving migrated seismic image using RTM to interpret the geological history involved with the evolution of permafrost.

  4. Pan-Arctic concentrations of mercury and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in marine zooplankton.

    Science.gov (United States)

    Pomerleau, Corinne; Stern, Gary A; Pućko, Monika; Foster, Karen L; Macdonald, Robie W; Fortier, Louis

    2016-05-01

    Zooplankton play a central role in marine food webs, dictating the quantity and quality of energy available to upper trophic levels. They act as "keystone" species in transfer of mercury (Hg) up through the marine food chain. Here, we present the first Pan-Arctic overview of total and monomethylmercury concentrations (THg and MMHg) and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in selected zooplankton species by assembling data collected between 1998 and 2012 from six arctic regions (Laptev Sea, Chukchi Sea, southeastern Beaufort Sea, Canadian Arctic Archipelago, Hudson Bay and northern Baffin Bay). MMHg concentrations in Calanus spp., Themisto spp. and Paraeuchaeta spp. were found to increase with higher δ(15)N and lower δ(13)C. The southern Beaufort Sea exhibited both the highest THg and MMHg concentrations. Biomagnification of MMHg between Calanus spp. and two of its known predators, Themisto spp. and Paraeuchaeta spp., was greatest in the southern Beaufort Sea. Our results show large geographical variations in Hg concentrations and isotopic signatures for individual species related to regional ecosystem features, such as varying water masses and freshwater inputs, and highlight the increased exposure to Hg in the marine food chain of the southern Beaufort Sea. PMID:26874765

  5. Leading By Example: Canada and its Arctic Stewardship Role

    DEFF Research Database (Denmark)

    Burke, Danita Catherine

    2016-01-01

    The notion that Canada is the steward of the fragile Arctic environment is a part of the fabric of the Canadian narrative about the country’s relationship with the Arctic region. In light of political, legal and environmental changes impacting Arctic politics, this paper argues that it is important...... to examine the circumstances which led to the creation and success of Canada’s stewardship role and its implications for Canadian and international shipping in the Arctic region before any changes are made to the governance of the region through unilateral legislation changes or new international...... agreements. This paper explores the origins of Canada’s image as the steward of the Arctic environment which started with the 1970 Arctic Waters Pollution Prevention Act legislation and addresses the central research questions, how did Canada’s role as the steward of the Arctic environment begin and evolve...

  6. Vegetation biomass, leaf area index, and NDVI patterns and relationships along two latitudinal transects in arctic tundra

    Science.gov (United States)

    Epstein, H. E.; Walker, D. A.; Raynolds, M. K.; Kelley, A. M.; Jia, G.; Ping, C.; Michaelson, G.; Leibman, M. O.; Kaarlejärvi, E.; Khomutov, A.; Kuss, P.; Moskalenko, N.; Orekhov, P.; Matyshak, G.; Forbes, B. C.; Yu, Q.

    2009-12-01

    Analyses of vegetation properties along climatic gradients provide first order approximations as to how vegetation might respond to a temporally dynamic climate. Until recently, no systematic study of tundra vegetation had been conducted along bioclimatic transects that represent the full latitudinal extent of the arctic tundra biome. Since 1999, we have been collecting data on arctic tundra vegetation and soil properties along two such transects, the North American Arctic Transect (NAAT) and the Yamal Arctic Transect (YAT). The NAAT spans the arctic tundra from the Low Arctic of the North Slope of Alaska to the polar desert of Cape Isachsen on Ellef Ringnes Island in the Canadian Archipelago. The Yamal Arctic Transect located in northwest Siberia, Russia, presently ranges from the forest-tundra transition at Nadym to the High Arctic tundra on Belyy Ostrov off the north coast of the Yamal Peninsula. The summer warmth indices (SWI - sum of mean monthly temperatures greater than 0°C) range from approximately 40 °C months to 3 °C months from south to north. For largely zonal sites along these transects, we systematically collected leaf area index (LAI-2000 Plant Canopy Analyzer), normalized difference vegetation index (NDVI - PSII hand-held spectro-radiometer), and vegetation biomass (clip harvests). Site-averaged LAI ranges from 1.08 to 0 along the transects, yet can be highly variable at the landscape scale. Site-averaged NDVI ranges from 0.67 to 0.26 along the transects, and is less variable than LAI at the landscape scale. Total aboveground live biomass ranges from approximately 700 g m-2 to < 50 g m-2 along the NAAT, and from approximately 1100 g m-2 to < 400 g m-2 along the YAT (not including tree biomass at Nadym). LAI and NDVI are highly correlated logarithmically (r = 0.80) for the entire dataset. LAI is significantly related to total aboveground (live plus dead) vascular plant biomass, although there is some variability in the data (r = 0.63). NDVI is

  7. Modern and historical fluxes of halogenated organic contaminants to a lake in the Canadian arctic, as determined from annually laminated sediment cores.

    Science.gov (United States)

    Stern, G A; Braekevelt, E; Helm, P A; Bidleman, T F; Outridge, P M; Lockhart, W L; McNeeley, R; Rosenberg, B; Ikonomou, M G; Hamilton, P; Tomy, G T; Wilkinson, P

    2005-04-15

    Two annually laminated cores collected from Lake DV09 on Devon Island in May 1999 were dated using 210Pb and 137Cs, and analyzed for a variety of halogenated organic contaminants (HOCs), including polychlorinated biphenyls (PCBs), organochlorine pesticides, short-chain polychlorinated n-alkanes (sPCAs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated diphenyl ethers (PBDEs). Dry weight HOC concentrations in Lake DV09 sediments were generally similar to other remote Arctic lakes. Maximum HOC fluxes often agreed well with production maxima, although many compound groups exhibited maxima at or near the sediment surface, much later than peak production. The lower than expected HOC concentrations in older sediment slices may be due to anaerobic degradation and possibly to dilution resulting from a temporary increase in sedimentation rate observed between the mid-1960s and 1970s. Indeed, temporal trends were more readily apparent for those compound classes when anaerobic metabolites were also analyzed, such as for DDT and toxaphene. However, it is postulated here for the first time that the maximum or increasing HOC surface fluxes observed for many of the major compound classes in DV09 sediments may be influenced by climate variation and the resulting increase in algal primary productivity which could drive an increasing rate of HOC scavenging from the water column. Both the fraction (F(TC)) and enantiomer fraction (EF) of trans-chlordane (TC) decreased significantly between 1957 and 1997, suggesting that recent inputs to the lake are from weathered chlordane sources. PCDD/Fs showed a change in sources from pentachlorophenol (PeCP) in the 1950s and 1960s to combustion sources into the 1990s. Improvements in combustion technology may be responsible for the reducing the proportion of TCDF relative to OCDD in the most recent slice. PMID:15866277

  8. Modern and historical fluxes of halogenated organic contaminants to a lake in the Canadian arctic, as determined from annually laminated sediment cores

    International Nuclear Information System (INIS)

    Two annually laminated cores collected from Lake DV09 on Devon Island in May 1999 were dated using 210Pb and 137Cs, and analyzed for a variety of halogenated organic contaminants (HOCs), including polychlorinated biphenyls (PCBs), organochlorine pesticides, short-chain polychlorinated n-alkanes (sPCAs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated diphenyl ethers (PBDEs). Dry weight HOC concentrations in Lake DV09 sediments were generally similar to other remote Arctic lakes. Maximum HOC fluxes often agreed well with production maxima, although many compound groups exhibited maxima at or near the sediment surface, much later than peak production. The lower than expected HOC concentrations in older sediment slices may be due to anaerobic degradation and possibly to dilution resulting from a temporary increase in sedimentation rate observed between the mid-1960s and 1970s. Indeed, temporal trends were more readily apparent for those compound classes when anaerobic metabolites were also analyzed, such as for DDT and toxaphene. However, it is postulated here for the first time that the maximum or increasing HOC surface fluxes observed for many of the major compound classes in DV09 sediments may be influenced by climate variation and the resulting increase in algal primary productivity which could drive an increasing rate of HOC scavenging from the water column. Both the fraction (F TC) and enantiomer fraction (EF) of trans-chlordane (TC) decreased significantly between 1957 and 1997, suggesting that recent inputs to the lake are from weathered chlordane sources. PCDD/Fs showed a change in sources from pentachlorophenol (PeCP) in the 1950s and 1960s to combustion sources into the 1990s. Improvements in combustion technology may be responsible for the reducing the proportion of TCDF relative to OCDD in the most recent slice

  9. Salt Marshes of the Arctic National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this study was to map all salt marshes along the coastline of the Arctic National Wildlife Refuge, from the Canning River to the Canadian border....

  10. Characteristics of water-vapour inversions observed over the Arctic by Atmospheric Infrared Sounder (AIRS and radiosondes

    Directory of Open Access Journals (Sweden)

    A. Devasthale

    2011-05-01

    Full Text Available An accurate characterization of the vertical structure of the Arctic atmosphere is useful in climate change and attribution studies as well as for the climate modelling community to improve projections of future climate over this highly sensitive region. Here, we investigate one of the dominant features of the vertical structure of the Arctic atmosphere, i.e. water-vapour inversions, using eight years of Atmospheric Infrared Sounder data (2002–2010 and radiosounding profiles released from the two Arctic locations (North Slope of Alaska at Barrow and during SHEBA. We quantify the characteristics of clear-sky water vapour inversions in terms of their frequency of occurrence, strength and height covering the entire Arctic for the first time.

    We found that the frequency of occurrence of water-vapour inversions is highest during winter and lowest during summer. The inversion strength is, however, higher during summer. The observed peaks in the median inversion-layer heights are higher during the winter half of the year, at around 850 hPa over most of the Arctic Ocean, Siberia and the Canadian Archipelago, while being around 925 hPa during most of the summer half of the year over the Arctic Ocean. The radiosounding profiles agree with the frequency, location and strength of water-vapour inversions in the Pacific sector of the Arctic. In addition, the radiosoundings indicate that multiple inversions are the norm with relatively few cases without inversions. The amount of precipitable water within the water-vapour inversion structures is estimated and we find a distinct, two-mode contribution to the total column precipitable water. These results suggest that water-vapour inversions are a significant source to the column thermodynamics, especially during the colder winter and spring seasons. We argue that these inversions are a robust metric to test the reproducibility of thermodynamics within climate models. An accurate statistical

  11. Arctic cushion plants as fallout 'monitors'

    International Nuclear Information System (INIS)

    The internal distribution of fallout 137Cs was determined for arctic cushion plants Dryas integrifolia, Silene acaulis and the bryophytes Rhacomitrium lanuginosum and Polytrichum juniperinum collected at various latitudes in Canadian Arctic. The results indicate that these plants have functioned as biological monitors of radioactive fallout and it is suggested that analysis of the internal distribution of 137Cs could serve as a model for other airborne contaminants. (author)

  12. New geological data of New Siberian Archipelago

    Science.gov (United States)

    Sobolev, Nikolay; Petrov, Evgeniy

    2014-05-01

    The area of New Siberian Archipelago (NSA) encompasses different tectonic blocks is a clue for reconstruction of geological structure and geodynamic evolution of East Arctic. According to palaeomagnetic study two parts of the archipelago - Bennett and Anjou Islands formed a single continental block at least from the Early Palaeozoic. Isotope dating of De Long Islands igneous and sedimentary rocks suggests Neoproterozoic (Baikalian) age of its basement. The De Long platform sedimentary cover may be subdivided into two complexes: (1) intermediate of PZ-J variously deformed and metamorphosed rocks and (2) K-KZ of weakly lithified sediments. The former complex comprises the Cambrian riftogenic volcanic-clastic member which overlain by Cambrian-Ordovician turbiditic sequence, deposited on a continental margin. This Lower Palaeozoic complex is unconformably overlain by Early Cretaceous (K-Ar age of c.120 Ma) basalts with HALIP petrochemical affinities. In Anjou Islands the intermediate sedimentary complex encompasses the lower Ordovician -Lower Carboniferous sequence of shallow-marine limestone and subordinate dolomite, mudstone and sandstone that bear fossils characteristic of the Siberian biogeographic province. The upper Mid Carboniferous - Jurassic part is dominated by shallow-marine clastic sediments, mainly clays. The K-KZ complex rests upon the lower one with angular unconformity and consists mainly of coal-bearing clastic sediments with rhyolite lavas and tuffs in the bottom (117-110 Ma by K-Ar) while the complexe's upper part contains intraplate alkalic basalt and Neogene-Quaternary limburgite. The De-Long-Anjou block's features of geology and evolution resemble those of Wrangel Island located some 1000 km eastward. The Laptev Sea shelf outcrops in intrashelf rises (Belkovsky and Stolbovoy Islands) where its geology and structure may be observed directly. On Belkovsky Island non-dislocated Oligocene-Miocene sedimentary cover of littoral-marine coal

  13. Detrital zircons (U-Pb and Lu-Hf) and host hemipelagic sediments (Pb-Sr-Nd-Os) from the Polar Arctic

    Science.gov (United States)

    Kapitonov, Igor; Belyatsky, Boris; Petrov, Eugeny; Sergeev, Sergey

    2015-04-01

    We studied deep-sea sediments from 6 sampling sites on the steep slopes of seamounts that accumulate during the last one million years. The goal of the study - to characterize the bedrock, which are coming to the surface from the overlying deposits for most of these steep slopes and weathering give talus deposits accumulating at the foot of the slopes.. The result proved to be similar enough for heavy fraction of all sediment columns spaced along the Alpha-Mendeleev Ridge on a 450 km. This suggest provenance similarity, which can be achieved either by erosion of the same rocks composing this ridge or by continental origin of material. We conducted control sampling of deep-water pelagic sediments in several remote places and held various positions with respect to the morphological ocean structure: on the flatten top surface of the deep-water ridge, on the bottom surface of the Amundsen Basin, 100 km to the west of the Lomonosov Ridge, at the Geophysicists Spur from the eastern side of the Lomonosov Ridge, and from the Laptev Sea. There are five control samples, which showed some local differences in the composition and distribution of zircon ages, with a total general similarity of these distributions. This fact indicates move the character of precipitation, as on the surface elevations and depressions in the sediment at the expense of local erosion of bedrock can not be formed. One of the sources of the Arctic Ocean sediments are traditionally considered «dirty» sea ice carrying material from the Canadian Archipelago, which are moved into the central part of the ocean due to Bofourt Gear flow. However, the distribution of zircon ages, revealed in the sediments, differs significantly from similar distributions for detrital zircon of Arctic coast of Alaska, the Canadian Archipelago, Greenland, Europe (Baltic Shield) and North America. But there are a lot more similarities with the zircon ages distributions typical for Asian continent, excluding China and India

  14. Large, omega-3 rich, pelagic diatoms under Arctic sea ice: sources and implications for food webs.

    Science.gov (United States)

    Duerksen, Steven W; Thiemann, Gregory W; Budge, Suzanne M; Poulin, Michel; Niemi, Andrea; Michel, Christine

    2014-01-01

    Pelagic primary production in Arctic seas has traditionally been viewed as biologically insignificant until after the ice breakup. There is growing evidence however, that under-ice blooms of pelagic phytoplankton may be a recurrent occurrence. During the springs of 2011 and 2012, we found substantial numbers (201-5713 cells m-3) of the large centric diatom (diameter >250 µm) Coscinodiscus centralis under the sea ice in the Canadian Arctic Archipelago near Resolute Bay, Nunavut. The highest numbers of these pelagic diatoms were observed in Barrow Strait. Spatial patterns of fatty acid profiles and stable isotopes indicated two source populations for C. centralis: a western origin with low light conditions and high nutrients, and a northern origin with lower nutrient levels and higher irradiances. Fatty acid analysis revealed that pelagic diatoms had significantly higher levels of polyunsaturated fatty acids (mean ± SD: 50.3 ± 8.9%) compared to ice-associated producers (30.6 ± 10.3%) in our study area. In particular, C. centralis had significantly greater proportions of the long chain omega-3 fatty acid, eicosapentaenoic acid (EPA), than ice algae (24.4 ± 5.1% versus 13.7 ± 5.1%, respectively). Thus, C. centralis represented a significantly higher quality food source for local herbivores than ice algae, although feeding experiments did not show clear evidence of copepod grazing on C. centralis. Our results suggest that C. centralis are able to initiate growth under pack ice in this area and provide further evidence that biological productivity in ice-covered seas may be substantially higher than previously recognized. PMID:25473949

  15. Arctic Newcomers

    DEFF Research Database (Denmark)

    Tonami, Aki

    2013-01-01

    Interest in the Arctic region and its economic potential in Japan, South Korea and Singapore was slow to develop but is now rapidly growing. All three countries have in recent years accelerated their engagement with Arctic states, laying the institutional frameworks needed to better understand an...

  16. Environmental marine geology of the Arctic Ocean

    International Nuclear Information System (INIS)

    The Arctic Ocean and its ice cover are major regulators of Northern Hemisphere climate, ocean circulation and marine productivity. The Arctic is also very sensitive to changes in the global environment because sea ice magnifies small changes in temperature, and because polar regions are sinks for air pollutants. Marine geology studies are being carried out to determine the nature and rate of these environmental changes by study of modern ice and sea bed environments, and by interpretation of geological records imprinted in the sea floor sediments. Sea ice camps, an ice island, and polar icebreakers have been used to study both western and eastern Arctic Ocean basins. Possible early warning signals of environmental changes in the Canadian Arctic are die-back in Arctic sponge reefs, outbreaks of toxic dinoflagellates, and pesticides in the marine food chain. Eastern Arctic ice and surface waters are contaminated by freon and radioactive fallout from Chernobyl. At present, different sedimentary processes operate in the pack ice-covered Canadian polar margin than in summer open waters off Alaska and Eurasia. The geological records, however, suggest that a temperature increase of 1-4C would result in summer open water throughout the Arctic, with major changes in ocean circulation and productivity of waters off Eastern North America, and more widespread transport of pollutants from eastern to western Arctic basins. More studies of longer sediment cores are needed to confirm these interpretations, but it is now clear that the Arctic Ocean has been the pacemaker of climate change during the past 1 million years

  17. Environmental marine geology of the Arctic Ocean

    International Nuclear Information System (INIS)

    The Arctic Ocean and its ice cover are major regulators of Northern Hemisphere climate, ocean circulation and marine productivity. The Arctic is also very sensitive to changes in the global environment because sea ice magnifies small changes in temperature, and because polar regions are sinks for air pollutants. Marine geology studies are being carried out to determine the nature and rate of these environmental changes by study of modem ice and sea-bed environments, and by interpretation of geological records imprinted in the sea-floor sediments. Sea ice camps, an ice island, and polar icebreakers have been used to study both western and eastern Arctic Ocean basins. Possible early warning signals of environmental changes in the Canadian Arctic are die-back in Arctic sponge reefs, outbreaks of toxic dinoflagellates, and pesticides in the marine food chain. Eastern Arctic ice and surface waters are contaminated by freon and radioactive fallout from Chernobyl. At present, different sedimentary processes operate in the pack ice-covered Canadian polar margin than in summer open waters off Alaska and Eurasia. The geological records, however, suggest that a temperature increase of 1-4 degree C would result in summer open water throughout the Arctic, with major changes in ocean circulation and productivity of waters off Eastern North America, and more widespread transport of pollutants from eastern to western Arctic basins. More studies of longer sediment cores are needed to confirm these interpretations, but is is now clear that the Arctic Ocean has been the pacemaker of climate change during the past 1 million years

  18. Island Movements: Thinking with the Archipelago

    Directory of Open Access Journals (Sweden)

    Jonathan Pugh

    2013-05-01

    Full Text Available Whether in Homer or Plato, Shakespeare or Huxley, throughout history, thinking about islands has shaped how we think about human nature and our place in the world. However, to date archipelagos have received far less attention. This is problematic because we live, increasingly, in a world of island-island movements and not static forms. Not only in the more obvious cases of the Caribbean, Hawaii or the Philippines but, as Stratford et al (2011 say, many ‘continental forms’ like Canada and Australia are in fact archipelagos composed of thousands of island movements. To this list we can add more manufactured archipelagos: wind turbine arrays, industrial oil and military constellations. The key question therefore arises: what does it mean to think with the archipelago? This paper argues firstly that archipelagic thinking denaturalizes the conceptual basis of space and place, and therefore engages ‘the spatial turn’ presently sweeping the social sciences and humanities. Secondly, such thinking highlights the trope of what I call ‘metamorphosis’, of the adaptation and transformation of material, cultural and political practices through island movements. In both cases, I argue that thinking with the archipelago requires an important shift in how we frame analysis and engagement.

  19. Arctic Watch

    Science.gov (United States)

    Orcutt, John; Baggeroer, Arthur; Mikhalevsky, Peter; Munk, Walter; Sagen, Hanne; Vernon, Frank; Worcester, Peter

    2015-04-01

    The dramatic reduction of sea ice in the Arctic Ocean will increase human activities in the coming years. This will be driven by increased demand for energy and the marine resources of an Arctic Ocean more accessible to ships. Oil and gas exploration, fisheries, mineral extraction, marine transportation, research and development, tourism and search and rescue will increase the pressure on the vulnerable Arctic environment. Synoptic in-situ year-round observational technologies are needed to monitor and forecast changes in the Arctic atmosphere-ice-ocean system at daily, seasonal, annual and decadal scales to inform and enable sustainable development and enforcement of international Arctic agreements and treaties, while protecting this critical environment. This paper will discuss multipurpose acoustic networks, including subsea cable components, in the Arctic. These networks provide communication, power, underwater and under-ice navigation, passive monitoring of ambient sound (ice, seismic, biologic and anthropogenic), and acoustic remote sensing (tomography and thermometry), supporting and complementing data collection from platforms, moorings and autonomous vehicles. This paper supports the development and implementation of regional to basin-wide acoustic networks as an integral component of a multidisciplinary, in situ Arctic Ocean Observatory.

  20. Distribution and numbers of breeding ivory gulls Pagophila eburnea in Severnaja Zemlja, Russian Arctic

    NARCIS (Netherlands)

    Volkov, AE; de Korte, J.

    1996-01-01

    The ivory gull Pagophila eburnea has a semi-circumpolar distribution with breeding sites in the High Arctic. Data about ivory gulls in the Severnaja Zemlja Archipelago (Siberia) were collected from 1991 to 1995. The numbers of breeding ivory gulls and their egg-laying period are correlated with the

  1. I Am Canadian

    DEFF Research Database (Denmark)

    Goddard, Joe

    "I Am Canadian: Immigration and Multiculturalism in the True North" looks at Canadian immigration history from a contemporary point of view. The article scrutinizes recent discussions on dual nationality and what this may mean for Canadianness......."I Am Canadian: Immigration and Multiculturalism in the True North" looks at Canadian immigration history from a contemporary point of view. The article scrutinizes recent discussions on dual nationality and what this may mean for Canadianness....

  2. Cossidae of the Socotra Archipelago (Yemen

    Directory of Open Access Journals (Sweden)

    Robert Borth

    2011-08-01

    Full Text Available The taxonomy of the family Cossidae (Lepidoptera of the Socotra Archipelago is revised. Five species are recognized, including two new species (Mormogystia brandstetteri and Meharia hackeri, and dubious identifications and records are discussed. Adults and genitalia are illustrated and bionomic details, molecular evidence and a synonymic checklist of Socotra Cossidae genera is provided. A review of their distribution reveals that at least 80 percent of Socotro`s Cossidae species are unique to the archipelago which is renowned for its endemism.

  3. Gastrointestinal helminths of arctic foxes (Alopex lagopus) from different bioclimatological regions in Greenland

    DEFF Research Database (Denmark)

    Kapel, C. M O; Nansen, P.

    1996-01-01

    areas in northwest Greenland in close proximity to the Canadian Archipelago. Foxes from air bases, which are known to feed intensively on garbage, harbored similar numbers of species compared to foxes from settlements in the same regions. The number of T. leonina in animals less than 1 yr of age was...

  4. Ice rafting history and paleoceanographic reconstructions of Core 08P23 from southern Chukchi Plateau, western Arctic Ocean since Marine Isotope Stage 3

    Institute of Scientific and Technical Information of China (English)

    ZHANG Taoliang; WANG Rujian; XIAO Wenshen; CHEN Zhihua; CHEN Jianfang; CHENG Zhenbo; SUN Yechen

    2015-01-01

    Multiproxy investigations have been performed on Core 08P23 collected from the Chukchi Plateau, the western Arctic Ocean, during the Third Chinese National Arctic Expedition. The core was dated back to Ma-rine Isotope Stage (MIS) 3 by a combination of Accelerator Mass Spectrometric (AMS) carbon-14 dating and regional core correlation. A total of five prominent ice-rafted detritus (IRD) events were recognized in MIS 2 and MIS 3. The IRD sources in MIS 3 are originated from vast carbonate rock outcrops of the Canadian Arctic Archipelago and clastic quartz in MIS 2 may have a Eurasian origin. Mostδ18O andδ13C values of Neogloboquadrina pachyderma (sinistral) (Nps) in Core 08P23 are lighter than the average values of surface sediments. The lighterδ18O andδ13C values of Nps in the two brown layers in MIS 1 and MIS 3 were resulted from meltwater events; and those in the gray layers in MIS 3 were caused by the enhanced sea ice formation. Theδ18O values varied inversely withδ13C in MIS 2 indicate that the study area was covered by thick sea ice or ice sheet with low temperature and little meltwater, which prevented the biological productivity and sea-atmosphere exchange, as well as water mass ventilation. The covaried light values ofδ18O andδ13C in MIS 1 and MIS 3 were resulted from meltwater and/or brine injection.

  5. A CANOEING PACKAGE THROUGH THE ARCHIPELAGO : Product Development for 7 Bridges Archipelago

    OpenAIRE

    Rajbhandari, Sujan

    2012-01-01

    This thesis was aimed to result in a quality canoeing product for the tourism organization 7 Bridges Archipelago. The motive for the product extension was based on the geographical potential and customer demands in the Western coastal region of Finland. Therefore 7 Bridges Archipelago acted as the commissioning party for this thesis, as the organization will be provided with a completely developed tour package for canoeing. This was a practice-based thesis. The first section of this work ...

  6. Security in the Arctic region. Coming in from the Cold War: Arctic security in the emerging global climate: A view from Canada

    International Nuclear Information System (INIS)

    The article briefly discusses the strategic importance of the Arctic during the cold war years, before moving on to a consideration of the Canadian approach to the region and an outline of various Canadian governmental and private initiatives. The question of whether confidence and security building measures established in other areas are suitable for transfer to the Arctic is answered and a tentative list of some measures that might most appropriately and effectively serve to make the Arctic more secure is put forward for later and fuller discussions

  7. Shear Wave Splitting Beneath the Galapagos Archipelago

    Science.gov (United States)

    Fontaine, F. R.; Burkett, P. G.; Hooft, E. E.; Toomey, D. R.; Solomon, S. C.; Silver, P. G.

    2004-12-01

    We report measurements of teleseismic shear wave splitting in the Galápagos Archipelago. The inferred lateral variations in azimuthal anisotropy allow us to examine the dynamics of an evolving hotspot-ridge system. The data are from SKS and SKKS phases, as well as S waves from deep sources, recorded by a relatively dense network of 10 portable broadband seismometers deployed from 1999 to 2003 for the IGUANA (Imaging Galápagos Upwelling and Neotectonics of the Archipelago) experiment and from the GSN broadband station in Santa Cruz (PAYG). We find a delay time between fast and slow shear waves of 0.4 to 0.9 s and fast polarization directions of N85-90° E beneath five stations at the leading and southern edge of the archipelago. Despite clear seismic signals, we did not find any anisotropy at the six stations located in the interior of the archipelago. For those stations that show shear wave splitting, there is an increase in the delay time toward the expected location of the Galápagos hotspot at the western edge of the archipelago. With the exception of Española, fast polarization directions (N85-90° E) are close to the current direction of absolute plate motion of the overlying Nazca plate (N91° E). The lack of azimuthal anisotropy in the interior of the archipelago is interpreted as an absence of strongly oriented mantle fabric beneath these stations. The apparent isotropy in this dynamic region, where we expect considerable mantle strain, is surprising. It is not likely that the olivine a-axis is oriented vertically beneath the interior of the archipelago as the Galápagos plume is thought to lie at the western edge. It is also unlikely that there are two layers of perpendicularly-oriented anisotropy which are solely confined to the center of the archipelago. However, there appears to be some correlation between the region of apparent isotropy and a zone of anomalously low upper mantle velocities imaged beneath Santiago and Marchena from surface waves by

  8. Circumpolar measurements of speciated mercury, ozone and carbon monoxide in the boundary layer of the Arctic Ocean

    Directory of Open Access Journals (Sweden)

    J. Sommar

    2010-06-01

    Full Text Available Using the Swedish icebreaker Oden as a platform, continuous measurements of airborne mercury (gaseous elemental mercury (Hg0, divalent gaseous mercury species HgIIX2(g (acronym RGM and mercury attached to particles (PHg and some long-lived trace gases (carbon monoxide CO and ozone O3 were performed over the North Atlantic and the Arctic Ocean. The measurements were performed for nearly three months (July–September 2005 during the Beringia 2005 expedition (from Göteborg, Sweden via the proper Northwest Passage to the Beringia region Alaska – Chukchi Penninsula – Wrangel Island and in-turn via a north-polar transect to Longyearbyen, Spitsbergen. The Beringia 2005 expedition was the first time that these species have been measured during summer over the Arctic Ocean going from 60° to 90° N.

    During the North Atlantic transect, concentration levels of Hg0, CO and O3 were measured comparable to typical levels for the ambient mid-hemispheric average. However, a rapid increase of Hg0 in air and surface water was observed when entering the ice-covered waters of the Canadian Arctic archipelago. Large parts of the measured waters were supersaturated with respect to Hg0, reflecting a strong disequilibrium. Heading through the sea ice of the Arctic Ocean, a fraction of the strong Hg0 pulse in the water was transferred with some time-delay into the air samples collected ~20 m above sea level. Several episodes of elevated Hg0 in air were encountered along the sea ice route with higher mean concentration (1.81±0.43 ng m−3 compared to the marine boundary layer over ice-free Arctic oceanic waters (1.55±0.21 ng m−3. In addition, the bulk of the variance in the temporal series of Hg0 concentrations was observed during July. The Oden Hg0 observations compare in this aspect very favourably

  9. The Arctic

    International Nuclear Information System (INIS)

    Global climate change in the Arctic is a growing concern. Research has already documented pronounced changes, and models predict that increases in temperature from anthropogenic influences could be considerably higher than the global average. The impacts of climate change on Arctic ecosystems are complex and difficult to predict because of the many interactions within ecosystem, and between many concurrently changing environmental variables. Despite the global consequences of change in the Arctic climate the monitoring of basic abiotic as well as biotic parameters are not adequate to assess the impact of global climate change. The uneven geographical location of present monitoring stations in the Arctic limits the ability to understand the climate system. The impact of previous variations and potential future changes to ecosystems is not well understood and need to be addressed. At this point, there is no consensus of scientific opinion on how much of the current changes that are due to anthropogenic influences or to natural variation. Regardless of the cause, there is a need to investigate and assess current observations and their effects to the Arctic. In this chapter examples from both terrestrial and marine ecosystems from ongoing monitoring and research projects are given. (LN)

  10. Arctic bioremediation

    International Nuclear Information System (INIS)

    Cleanup of oil and diesel spills on gravel pads in the Arctic has typically been accomplished by utilizing a water flushing technique to remove the gross contamination or excavating the spill area and placing the material into a lined pit, or a combination of both. Enhancing the biological degradation of hydrocarbon (bioremediation) by adding nutrients to the spill area has been demonstrated to be an effective cleanup tool in more temperate locations. However, this technique has never been considered for restoration in the Arctic because the process of microbial degradation of hydrocarbon in this area is very slow. The short growing season and apparent lack of nutrients in the gravel pads were thought to be detrimental to using bioremediation to cleanup Arctic oil spills. This paper discusses the potential to utilize bioremediation as an effective method to clean up hydrocarbon spills in the northern latitudes

  11. Arctic bioremediation

    International Nuclear Information System (INIS)

    Cleanup of oil and diesel spills on gravel pads in the Arctic has typically been accomplished by utilizing a water flushing technique to remove the gross contamination or excavating the spill area and placing the material into a lined pit, or a combination of both. This paper discusses the potential to utilize bioremediation as an effective method to clean up hydrocarbon spills in the northern latitudes. Discussed are the results of a laboratory bioremediation study which simulated microbial degradation of hydrocarbon under arctic conditions

  12. Bioaccumulation of radiocaesium in Arctic seals.

    Science.gov (United States)

    Carroll, Jolynn; Wolkers, Hans; Andersen, Magnus; Rissanen, Kristina

    2002-12-01

    Seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. Their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. The purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. The study was carried out on harp, ringed, and bearded seals caught north of the island archipelago of Svalbard (82 degrees N) in 1999. The results are then compared with previous studies in order to elucidate factors responsible for bioaccumulation in Arctic seals. Concentrations of 137Cs were determined in muscle, liver and kidney samples from a total of 10 juvenile and one adult seal. The mean concentration in muscle samples for all animals was 0.23 +/- 0.045 Bq/kg f.w. 137Cs concentrations in both liver and kidney samples were near detection limits (approximately 0.2 Bq/kg f.w.). The results are consistent with previous studies indicating low levels of radiocaesium in Arctic seals in response to a long term trend of decreasing levels of 137Cs in the Barents Sea region. Bioconcentration factors (BCFs) estimated for seals from NE Svalbard are low, ranging from 34 to 130. Comparing these values with reported BCFs for Greenland seals from other sectors of the European Arctic, we suggest that the combination of physiological and ecological factors on radiocaesium bioaccumulation is comparable among different Arctic seal populations. The application of this work to Arctic monitoring and assessment programs is discussed. PMID:12523541

  13. Bioaccumulation of radiocaesium in Arctic seals

    International Nuclear Information System (INIS)

    Seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. Their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. The purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. The study was carried out on harp, ringed, and bearded seals caught north of the island archipelago of Svalbard (82 deg. N) in 1999. The results are then compared with previous studies in order to elucidate factors responsible for bioaccumulation in Arctic seals. Concentrations of 137Cs were determined in muscle, liver and kidney samples from a total of 10 juvenile and one adult seal. The mean concentration in muscle samples for all animals was 0.23±0.045 Bq/kg f.w. 137Cs concentrations in both liver and kidney samples were near detection limits (∼0.2 Bq/kg f.w.). The results are consistent with previous studies indicating low levels of radiocaesium in Arctic seals in response to a long term trend of decreasing levels of 137Cs in the Barents Sea region. Bioconcentration factors (BCFs) estimated for seals from NE Svalbard are low, ranging from 34 to 130. Comparing these values with reported BCFs for Greenland seals from other sectors of the European Arctic, we suggest that the combination of physiological and ecological factors on radiocaesium bioaccumulation is comparable among different Arctic seal populations. The application of this work to Arctic monitoring and assessment programs is discussed

  14. Bioaccumulation of radiocaesium in Arctic seals

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, JoLynn; Wolkers, Hans; Andersen, Magnus; Rissanen, Kristina

    2002-12-01

    Seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. Their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. The purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. The study was carried out on harp, ringed, and bearded seals caught north of the island archipelago of Svalbard (82 deg. N) in 1999. The results are then compared with previous studies in order to elucidate factors responsible for bioaccumulation in Arctic seals. Concentrations of {sup 137}Cs were determined in muscle, liver and kidney samples from a total of 10 juvenile and one adult seal. The mean concentration in muscle samples for all animals was 0.23{+-}0.045 Bq/kg f.w. {sup 137}Cs concentrations in both liver and kidney samples were near detection limits ({approx}0.2 Bq/kg f.w.). The results are consistent with previous studies indicating low levels of radiocaesium in Arctic seals in response to a long term trend of decreasing levels of {sup 137}Cs in the Barents Sea region. Bioconcentration factors (BCFs) estimated for seals from NE Svalbard are low, ranging from 34 to 130. Comparing these values with reported BCFs for Greenland seals from other sectors of the European Arctic, we suggest that the combination of physiological and ecological factors on radiocaesium bioaccumulation is comparable among different Arctic seal populations. The application of this work to Arctic monitoring and assessment programs is discussed.

  15. Circumpolar measurements of speciated mercury, ozone and carbon monoxide in the boundary layer of the Arctic Ocean

    Directory of Open Access Journals (Sweden)

    J. Sommar

    2009-10-01

    Full Text Available Using the Swedish icebreaker Oden as a platform, continuous measurements of airborne mercury (gaseous elemental mercury (Hg0, divalent mercury HgII(g (acronym RGM and mercury attached to particles (PHg and some long-lived trace gases (carbon monoxide CO and ozone O3 were performed over the North Atlantic and the Arctic Ocean. The measurements were performed for nearly three months (July–September, 2005 during the Beringia 2005 expedition (from Göteborg, Sweden via the proper Northwest Passage to the Beringia region Alaska – Chukchi Penninsula – Wrangel Island and in-turn via a north-polar transect to Longyearbyen, Spitsbergen. The Beringia 2005 expedition was the first time that these species have been measured during summer over the Arctic Ocean going from 60° to 90° N.

    During the North Atlantic transect, concentration levels of Hg0, CO and O3 were measured comparable to typical levels for the ambient mid-hemispheric average. However, a rapid increase of Hg0 in air and surface water was observed when entering the ice-covered waters of the Canadian Arctic archipelago. Large parts of the measured waters were supersaturated with respect to Hg0, reflecting a strong disequilibrium. Heading through the sea ice of the Arctic Ocean, a fraction of the strong Hg0} pulse in the water was spilled with some time-delay into the air samples collected ~20 m a.s.l. Several episodes of elevated Hg0(g were encountered along the sea ice route with higher mean concentration (1.81±0.43 ng m−3 compared to the marine boundary layer over ice-free oceanic waters (1.55±0.21 ng m−3. In addition, an overall majority of the variance in the temporal series of Hg0 concentrations was observed during July. Atmospheric boundary layer {O3} mixing ratios decreased when initially sailing northward. In the Arctic, an O

  16. Influence of sea ice on Arctic precipitation.

    Science.gov (United States)

    Kopec, Ben G; Feng, Xiahong; Michel, Fred A; Posmentier, Eric S

    2016-01-01

    Global climate is influenced by the Arctic hydrologic cycle, which is, in part, regulated by sea ice through its control on evaporation and precipitation. However, the quantitative link between precipitation and sea ice extent is poorly constrained. Here we present observational evidence for the response of precipitation to sea ice reduction and assess the sensitivity of the response. Changes in the proportion of moisture sourced from the Arctic with sea ice change in the Canadian Arctic and Greenland Sea regions over the past two decades are inferred from annually averaged deuterium excess (d-excess) measurements from six sites. Other influences on the Arctic hydrologic cycle, such as the strength of meridional transport, are assessed using the North Atlantic Oscillation index. We find that the independent, direct effect of sea ice on the increase of the percentage of Arctic sourced moisture (or Arctic moisture proportion, AMP) is 18.2 ± 4.6% and 10.8 ± 3.6%/100,000 km(2) sea ice lost for each region, respectively, corresponding to increases of 10.9 ± 2.8% and 2.7 ± 1.1%/1 °C of warming in the vapor source regions. The moisture source changes likely result in increases of precipitation and changes in energy balance, creating significant uncertainty for climate predictions. PMID:26699509

  17. Unilateral pollution control in the Northwest Passage : the Canadian NORDREG regulations in the context of UNCLOS, Article 234

    OpenAIRE

    Raspotnik, Andreas

    2011-01-01

    To safeguard the Canadian Arctic marine environment, Canada established an Arctic marine traffic system, known as the Northern Canada Vessel Traffic Services Zone Regulations (NORDREG). These mandatory regulations require most nongovernmental vessels to report information prior to entering, while operating within and upon exiting Canada’s northern/Arctic waters. Canada asserts that the traffic system is consistent with international law concerning ice-covered areas, in particular with the “Ar...

  18. High Arctic paleoenvironmental and Paleoclimatic changes in the Mid-Cretaceous

    Science.gov (United States)

    Herrle, Jens; Schröder-Adams, Claudia; Selby, David; Du Vivier, Alice; Flögel, Sascha; McAnena, Alison; Davis, William; Pugh, Adam; Galloway, Jennifer; Hofmann, Peter; Wagner, Thomas

    2014-05-01

    Although major progress in Cretaceous (145-66 Ma) paleoclimate and paleoceanography has been made during the last decades (e.g., Hay, 2008, 2011; Föllmi, 2012 and references therein), our knowledge of high latitudinal environmental change remains largely unknown compared to low- and mid-latitude marine and terrestrial environments. Drilling the Arctic Ocean remains challenging and expensive, whereas the Sverdrup Basin provides excellent exposures on land. To fully understand the climate and paleoceanographic dynamics of the warm, equable greenhouse world of the Cretaceous Period it is important to determine polar paleotemperatures and to study paleoceanographic changes in a well-established and continuous bio- and chemostratigraphic context. Exceptional exposures of Cretaceous sediments on the central to southern part of Axel Heiberg Island at a Cretaceous paleolatitude of about 71°N (Tarduno et al., 1998) provide a unique window on the Cretaceous Arctic paleoenvironment and climate history (Schröder-Adams et al., 2014). Here we present high-resolution records combining sedimentological studies, U-Pb zircon geochronology, marine organic carbon isotopes and initial 187Os/188Os data, TEX86-derived sea-surface temperatures (SST) and climate modelling, that constrain the timing and magnitude of major Oceanic Anoxic Events (OAEs) and climate events constructed from a ~1.8 km sedimentary succession exposed on Axel Heiberg and Ellef Ringnens islands in the Canadian Arctic Archipelago. The first high latitude application of initial 187Os/188Os data are agreeable with global profiles (Du Vivier et al., 2014) indicating the widespread magmatic pulse of the Caribbean Large Igneous Province (LIP) at the onset of OAE2 but also record the emplacement of local High Arctic LIP prior to the OAE2 in the Sverdrup Basin. Initial SST data suggest a slightly lower meridional temperature gradient during the Middle/Late Albian compared to present and a similar to the present one during

  19. Protest: The Canadian pulse

    International Nuclear Information System (INIS)

    This popularly written article compares Canadian attitudes to protests against nuclear power to those in the United States. Canadian protesters are more peaceful, expressing their opinions within the law. The article describes the main anti-nuclear groups in Canada and presents the results of public opinion surveys of Canadians on the use of nuclear power for generating electricity. (TI)

  20. On the influence of model physics on simulations of Arctic and Antarctic sea ice

    Directory of Open Access Journals (Sweden)

    F. Massonnet

    2011-09-01

    Full Text Available Two hindcast (1983–2007 simulations are performed with the global, ocean-sea ice models NEMO-LIM2 and NEMO-LIM3 driven by atmospheric reanalyses and climatologies. The two simulations differ only in their sea ice component, while all other elements of experimental design (resolution, initial conditions, atmospheric forcing are kept identical. The main differences in the sea ice models lie in the formulation of the subgrid-scale ice thickness distribution, of the thermodynamic processes, of the sea ice salinity and of the sea ice rheology. To assess the differences in model skill over the period of investigation, we develop a set of metrics for both hemispheres, comparing the main sea ice variables (concentration, thickness and drift to available observations and focusing on both mean state and seasonal to interannual variability. Based upon these metrics, we discuss the physical processes potentially responsible for the differences in model skill. In particular, we suggest that (i a detailed representation of the ice thickness distribution increases the seasonal to interannual variability of ice extent, with spectacular improvement for the simulation of the recent observed summer Arctic sea ice retreats, (ii the elastic-viscous-plastic rheology enhances the response of ice to wind stress, compared to the classical viscous-plastic approach, (iii the grid formulation and the air-sea ice drag coefficient affect the simulated ice export through Fram Strait and the ice accumulation along the Canadian Archipelago, and (iv both models show less skill in the Southern Ocean, probably due to the low quality of the reanalyses in this region and to the absence of important small-scale oceanic processes at the models' resolution (~1°.

  1. Features of shoreline displacement in the Holocene of Franz josef Land Archipelago

    Science.gov (United States)

    Barliaev, A.; Anisimov, M.

    2014-12-01

    Changes in the global sea level after the LGM caused the significant alteration in relation of land and sea in Arctic. The rise of the sea level in Arctic was accompanied with present tectonic processes. Marine terraces are formed with the combination of eustatic sea level fluctuations and glacioisostatic uplift of the territory with the significant role of complicated tectonic block movements. There are nearly about 150 radiocarbon ages data for Franz-Josef Land archipelago now. The represented conclusions are a generalization of the published data and results of our field researches with series of new radiocarbon dates. We managed to collect valuable factual material during the Russian Arctic National Park expedition in 2012. The distinctions of post-glacial rise of different islands and peculiarities of Holocene deglaciation were identified with the help of marine terraces analysis. The altitude of the terraces with the same age on different islands exceeds 15 meters in some cases. However, analysis of the data suggests that the continuous series of raised beaches from 35 m a.s.l. formed during the last 10000 years. It is impossible to build up an univocal model of emergence isobases with the existing data. Alexandra Land Island was the special object of this investigation. The large beach ridge from Lunar Ice Cap to Kropotkina Ice Cap divides the island on two parts. The northern one is covered with marine sediments, whereas the southern - with glaciofluvial sediments with negligible areas of marine sediments. The difference between the terraces' ages of Alexandra Land on the Dezhneva Bay shore and the northern shore of island suggests that: 1) In the early Holocene the rate of the transgression exceeded the tectonic uplift of the territory; 2) Formation of the large central beach ridge occurred near 6700 years ago, the maximum marine limit in the Alexandra Land Island; 3) The rate of the tectonic rise of the territory exceeded the eustatic sea level rise in

  2. Radiocesium body burdens in northern Canadians

    International Nuclear Information System (INIS)

    Whole body measurements were carried out on 1117 Canadians living in five Arctic communities during 1989 and 1990 in order to assess the uptake of radiocesium, from the lichen-caribou-human food chain. The Cs-137 body burdens increased with age, and were twice as high for men as for women. There was a discrepancy between the reported meat consumption and the measured body burdens. Average radiation doses from ingested radiocesium varied from 0.01 to 0.10 mSv/a. (author)

  3. Arctic Wears - Perspectives on Arctic Clothing

    OpenAIRE

    Konola, Sanna; Kähkönen, Päivi

    2015-01-01

    Arctic issues are rising around us on every field at the point of view of environment, sustainability, climate change, indigenous peoples’ rights, design and society, snow and ice building knowledge, challenges and possibilities in Arctic areas. The Arctic is written in Finland’s future strategies, and in 2017 Finland assumes the chairmanship of Arctic Council. In the northernmost university of European Union, University of Lapland, the northern issues have always been written in the DNA ...

  4. Arctic studies

    International Nuclear Information System (INIS)

    Idaho National Engineering Laboratory (INEL) conducted a study of contamination of the Arctic Ocean and surrounding areas in order to better understand the severity of the problem and identify possible parallels in the United States. The findings were published in a quarterly report as a part of this technical task plan (TTP). While many radioactive and hazardous material contamination sites in this region have been identified, official Russian statements indicate that contaminant concentrations are within normal limits and are currently confined to specific areas

  5. The Arctic Ocean and climate: A Perspective

    Science.gov (United States)

    Aagaard, K.; Carmack, E. C.

    The most likely effects of the Arctic Ocean on global climate are through the surface heat balance and the thermohaline circulation. The former is intimately related to the stratification of the Arctic Ocean, while the latter may be significantly controlled by outflow from the Arctic Ocean into the major convective regions to the south. Evaluating these issues adequately requires detailed knowledge of the density structure and circulation of the Arctic Ocean and of their variability. New long time series of temperature and salinity (T/S) from the Canadian Basin show a grainy T/S structure, probably on a horizontal scale of a few tens of kilometers. The temperature field is particularly inhomogeneous, since for cold water it is not greatly constrained by buoyancy forces. The simultaneous velocity time series show that the grainy T/S structure results from a complex eddy field, often with vertically or horizontally paired counter-rotating eddies drifting with a slow larger-scale flow. The ocean is therefore not well mixed on these scales. Finally, we note that the ventilation of the interior Arctic Ocean from the adjacent shelves appears to be highly variable on an interannual basis, and indeed may not be robust on longer time scales. In particular we note the absence, or near-absence, of deep ventilation of the Canadian Basin during the last 500 years. Based on the 14C model of Macdonald et al. [1993], however, we hypothesize that these same waters were ventilated prior to that time and that the deep convective shutdown about 500 years ago coincided with the end of the whale-hunting Thule culture. We further suggest that the two events had a common cause, viz., the increase of sea ice over the continental shelves during summer.

  6. Gray whale sightings in the Canadian Beaufort Sea, September 2014

    Science.gov (United States)

    Iwahara, Yuka; Fujiwara, Amane; Ito, Keizo; Miyashita, Kazushi; Mitani, Yoko

    2016-06-01

    Gray whales (Eschrichtius robustus) are distributed within the productive neritic and estuarine waters of the North Pacific Ocean, the Bering Sea, and adjacent waters of the Arctic Ocean. They migrate to high-latitude feeding grounds each spring. Their main feeding grounds in the Arctic include the Chirikov Basin, the northeastern Chukchi Sea from Pt. Hope to Cape Lisburne and Pt. Lay to Pt. Barrow, and the northwestern Chukchi Sea along the Chukotka coast. Although sightings are rare in the Canadian Beaufort Sea, we observed three gray whales in two groups in this area in September 2014. A mud plume was observed near one of the whales, suggesting the animal had been feeding. In the Alaskan Beaufort Sea, large-scale monitoring of the distributions of marine mammals has been continuously conducted since 1979; however, there has been less monitoring in the Canadian Beaufort Sea. Therefore, it is necessary to record opportunistic sightings, such as those described here.

  7. Estimating absorption coefficients of colored dissolved organic matter (CDOM using a semi-analytical algorithm for Southern Beaufort Sea (Canadian Arctic waters: application to deriving concentrations of dissolved organic carbon from space

    Directory of Open Access Journals (Sweden)

    A. Matsuoka

    2012-10-01

    Full Text Available A series of papers have suggested that freshwater discharge, including a large amount of dissolved organic matter (DOM, has increased since the middle of the 20th century. In this study, a semi-analytical algorithm for estimating light absorption coefficients of the colored fraction of DOM (CDOM was developed for Southern Beaufort Sea waters using remote sensing reflectance at six wavelengths in the visible spectral domain corresponding to MODIS ocean color sensor. This algorithm allows to separate colored detrital matter (CDM into CDOM and non-algal particles (NAP by determining NAP absorption using an empirical relationship between NAP absorption and particle backscattering coefficients. Evaluation using independent datasets, that were not used for developing the algorithm, showed that CDOM absorption can be estimated accurately to within an uncertainty of 35% and 50% for oceanic and turbid waters, respectively. In situ measurements showed that dissolved organic carbon (DOC concentrations were tightly correlated with CDOM absorption (r2 = 0.97. By combining the CDOM absorption algorithm together with the DOC versus CDOM relationship, it is now possible to estimate DOC concentrations in the near-surface layer of the Southern Beaufort Sea using satellite ocean color data. DOC concentrations in the surface waters were estimated using MODIS ocean color data, and the estimates showed reasonable values compared to in situ measurements. We propose a routine and near real-time method for deriving DOC concentrations from space, which may open the way to an estimate of DOC budgets for Arctic coastal waters.

  8. Circumpolar polynya characteristics in the Arctic between 2002/2003 and 2014/2015 as derived from MODIS thermal infrared imagery and ERA-Interim reanalysis

    Science.gov (United States)

    Preußer, Andreas; Willmes, Sascha; Heinemann, Günther; Paul, Stephan

    2016-04-01

    In this pan-Arctic study, high-resolution MODIS thermal infrared satellite data are used to infer spatial and temporal characteristics of 16 prominent coastal polynya regions and leads over the entire Arctic basin. Thin-ice thickness distributions (≤ 20cm) are calculated from MODIS ice-surface temperatures swath-data (MOD/MYD29), combined with ECMWF ERA-Interim atmospheric reanalysis data in an energy balance model for the last 13 winter-seasons (2002/2003 to 2014/2015; November to March). From all available swath-data, (quasi-) daily thin-ice thickness composites are computed in order to derive valuable quantities such as polynya area and total thermodynamic ice production. Two different cloud-cover correction schemes are applied to account for cloud and data gaps in the MODIS composites. During the investigated period, the average total wintertime accumulated ice production in all 16 polynya regions is estimated with about 1481 ± 262 km³, plus an additional 65 ± 59 km³ if leads in the central Arctic Ocean are taken into consideration. The largest contributions originate from the Kara Sea region and the North Water polynya (both ~19%) as well as scattered smaller polynyas in the Canadian Arctic Archipelago (all combined ~15%), while other well-known sites of polynya formation (Laptev Sea, Chukchi Sea) show smaller contributions with around 2-7%. Compared to another recently published pan-Arctic polynya study using coarser resolution passive microwave remote sensing data, our estimates are considerably larger due to distinct differences regarding the observed winter-period and applied polynya masks/reference areas. In addition, the use of high-resolution MODIS data increases the capability to resolve small scale (> 2km) thin-ice features such as leads, which therefore contribute to our ice production estimates. Despite the short record of 13 winter-seasons, positive trends in ice production can be detected for some regions of the eastern Arctic (most

  9. Simulating the natural variability of the freshwater budget of the Arctic ocean from the mid to late Holocene using LOVECLIM

    Science.gov (United States)

    Davies, F. J.; Goosse, H.; Renssen, H.

    2012-04-01

    The influence of freshwater on the long term climatic variability of the Arctic region is currently of significant interest. Alterations to the natural variability of the oceanic, terrestrial and atmospheric sources of freshwater to the Arctic ocean, caused by anthropogenic induced warming, are likely to have far reaching effects on oceanic processes and climate. A number of these changes are already observable, such as an intensification of the hydrological cycle, a 7% increase in Eurasian river runoff (1936-1999), a 9% reduction of sea-ice extent per decade (1979-2006), a 120km northward migration of permafrost in Northern Canada (1968-1994), and air temperatures 6°C warmer, in parts, from 2007 to 2010, when compared to the 1958-1996 average. All of these changes add another layer of complexity to understanding the role of the freshwater budget, and this makes it difficult to say with any certainty how these future changes will impact freshwater fluxes of the Arctic gateways, such as the Bering Strait, Fram Strait, Canadian Arctic Archipelago and the Barents Sea inflow. Despite these difficulties, there have been studies that have integrated the available data, from both in situ measurements and modelling studies, and used this as a basis to form a picture of the current freshwater budget, and then project upon these hypotheses for the future (Holland et al., 2007). However, one particular aspect of these future projections that is lacking is the accountability of how much future variance is attributable to both natural variability and anthropogenic influences. Here we present results of a mid to late (6-0ka) Holocene transient simulation, using the earth model of intermediate complexity, LOVECLIM (Goosse et al., 2010). The model is forced with orbital and greenhouse gas forcings appropriate for the time period. The results will highlight the natural variability of the oceanic, terrestrial and atmospheric components of the freshwater budget, over decadal and

  10. Status of the Coral Reefs of the Samoan Archipelago

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this study are twofold: (1) To determine the current status of coral reef fishes and their habitat throughout the Samoan Archipelago. This will be...

  11. Markets for Canadian oil

    International Nuclear Information System (INIS)

    This conference presentation presented charts and graphs on the market for Canadian oil. Graphs included crude oil and natural gas prices and heavy oil discount differential. Graphs depicting heavy oil economics such as bitumen blending with condensate were also included along with global crude oil reserves by country. Information on oil sands projects in the Athabasca, Peace River, and Cold Lake deposits was presented along with graphs on oil sands supply costs by recovery type; Canadian production for conventional, oil sands and offshore oil; new emerging oil sands crude types; and 2003 market demand by crude type in the United States and Canada. Maps included Canada and United States crude oil pipelines; western Canadian crude oil markets; long term oil pipeline expansion projects; Canadian and United States crude oil pipeline alternatives; and potential tanker markets for Canadian oil sands production. Lastly, the presentation provided graphs on 2003 refinery crude demand and California market demand. tabs., figs

  12. Influence of mountains on Arctic tropospheric ozone

    Science.gov (United States)

    Seabrook, Jeffrey; Whiteway, James

    2016-02-01

    Tropospheric ozone was measured above Ellesmere Island in the Canadian Arctic during spring of 2008 using a differential absorption lidar. The observations were carried out at Eureka Weather Station, which is located between various mountain ranges. Analysis of the observations revealed that mountains had a significant effect on the vertical distribution of ozone. Ozone depletion events were observed when air that had spent significant time near to the frozen surface of the Arctic Ocean reached Eureka. This air arrived at Eureka by flowing over the surrounding mountains. Surface level ozone depletions were not observed during periods when mountains blocked the flow of air from over the sea ice. In the case of blocking there was an enhancement in the amount of ozone near the surface as air from the midtroposphere descended in the lee of the mountains. Three case studies from spring of 2008 are described.

  13. Feasibility of hydrogen from renewable energy in the Arctic

    International Nuclear Information System (INIS)

    'Full text:' There is an abundance of renewable resources in the Canadian Arctic. Despite that diesel is still the conventional source used by homes and businesses for their electrical and space heating needs. Electrolysis of water to produce hydrogen using renewable resources is under investigation. A techno-economic feasibility has been conducted for hybrid systems including wind turbine, photovoltaic system, electrolyser and fuel cells. Different scenarios have been considered for meeting the needs of a small, remote community in the Arctic. Results will be presented indicating the most cost-effective Wind-PV-Electrolyser-Fuel Cell system for combined heat and power. (author)

  14. Spatial variations in the seasonality of organochlorine pesticides (OC) in Arctic air

    Energy Technology Data Exchange (ETDEWEB)

    Hung, H.; Blanchard, P. [Meteorological Service of Canada, Environment Canada, Toronto (Canada); Li, H.; Fellin, P. [AirZOne, Mississauga (Canada); Rosenberg, B.; Stern, G. [Freshwater Inst., Winnipeg (Canada); Barrie, L. [Environment Div., Atmospheric Research and Environment Programme, World Meteorological Organization, Geneva (Switzerland)

    2004-09-15

    Under the Canadian-managed Northern Contaminants Program (NCP), air samples were collected at three Canadian Arctic sites, namely Alert, Nunavut (1992-ongoing); Tagish, Yukon (Dec 1992 - Mar 1995) and Kinngait, Nunavut (Mar 1994 - Feb 1996, Oct 2000 - Sep 2002), as well as Dunai Island, Russia (Apr 1993 - May 1995) and Amderma, Russia (1999-2001) to assess the levels, transport pathways and potential sources of persistent organic pollutants (POPs) in the Arctic. A simultaneous sampling period exists between March 1994 and April 1995 at Alert, Tagish, Kinngait and Dunai Island. Spatial comparisons of organochlorine pesticide (OC) seasonality from this concurrent sampling period is presented in this study.

  15. Global warming is changing the dynamics of Arctic host–parasite systems

    OpenAIRE

    Kutz, S.J; Hoberg, E. P.; Polley, L.; Jenkins, E.J

    2005-01-01

    Global climate change is altering the ecology of infectious agents and driving the emergence of disease in people, domestic animals, and wildlife. We present a novel, empirically based, predictive model for the impact of climate warming on development rates and availability of an important parasitic nematode of muskoxen in the Canadian Arctic, a region that is particularly vulnerable to climate change. Using this model, we show that warming in the Arctic may have already radically altered the...

  16. Sources of light-absorbing aerosol in arctic snow and their seasonal variation

    OpenAIRE

    Hegg, D.A.; Warren, S. G.; Grenfell, T. C.; Doherty, S. J.; A. D. Clarke

    2010-01-01

    Two data sets consisting of measurements of light absorbing aerosols (LAA) in arctic snow together with suites of other corresponding chemical constituents are presented; the first from Siberia, Greenland and near the North Pole obtained in 2008, and the second from the Canadian arctic obtained in 2009. A preliminary differentiation of the LAA into black carbon (BC) and non-BC LAA is done. Source attribution of the light absorbing aerosols was done using a positive matrix factorization (PMF) ...

  17. Backcountry Travel Emergencies in Arctic Canada: A Pilot Study in Public Health Surveillance

    OpenAIRE

    Young, Stephanie K.; Taha B. Tabish; Pollock, Nathaniel J.; Kue Young, T.

    2016-01-01

    Residents in the Canadian Arctic regularly travel in remote, backcountry areas. This can pose risks for injuries and death, and create challenges for emergency responders and health systems. We aimed to describe the extent and characteristics of media-reported backcountry travel emergencies in two Northern Canadian territories (Nunavut and Northwest Territories). A case-series of all known incidents between 2004 and 2013 was established by identifying events in an online search of two media o...

  18. The evolution of Arctic marine mammals.

    Science.gov (United States)

    Harington, C R

    2008-03-01

    This review deals only with the evolutionary history of core Arctic marine mammals: polar bear (Ursus maritimus), walrus (Odobenus rosmarus), bearded seal (Erignathus barbatus), harp seal (Pagophilus groenlandica), ringed seal (Phoca hispida), bowhead whale (Balaena mysticetus), white whale (Delphinapterus leucas), and narwhal (Monodon monoceras). Sections on the evolutionary background of pinnipeds and whales help to provide a better perspective on these core species. Polar bears stemmed from brown bears about the Early to Middle Pleistocene. Fossils are rare; the earliest records are from approximately Early Weichselian deposits of Kew Bridge, London, and Svalbard. Existing Pacific and Atlantic walruses probably arose from splitting of a former Holarctic range during a Pleistocene glacial phase of extensive sea ice in the Canadian Arctic. The earliest known bearded seal remains are from Early to Middle Pleistocene deposits of Norfolk, England, and Cape Deceit, Alaska. Other Pleistocene fossils of this species are recorded from the North Sea, southwestern Sweden, and the Champlain Sea that existed in eastern North America approximately 12 000-10000 BP. The harp seal is the commonest pinniped in the Weichselian deposits of the southern North Sea. The earliest recorded fossil is from about 2 million years ago (2 Ma), from Ocean Point, Alaska. The earliest known Pleistocene ringed seal fossils are from last interglacial deposits near Teshekpuk Lake, Alaska, and Thule, Greenland, although an earlier (3 Ma?) specimen from Malaspina, Alaska, has been reported. This species seems to have been relatively abundant along the coasts of Prince of Wales Island, Alaska, during the Last Glacial Maximum. The bowhead whale probably originated in the high latitudes of the Northern Hemisphere. The earliest (mid-Wisconsinan) Canadian remains are from Ellesmere and Devon islands. More than 400 radiocarbon-dated bowhead remains have been used to reconstruct Holocene sea ice history in

  19. An Existentialist in Iqaluit: Existentialism and Reflexivity Informing Pedagogy in the Canadian North

    Science.gov (United States)

    Yue, Anthony R.

    2011-01-01

    Reflecting on the personal experience of teaching human resource management in the Canadian Arctic, the author explores the utility of an existentialist approach to pedagogy. The author outlines select aspects of existentialism that are pertinent to the teaching and discusses the implications of using reflexive existential thought as guidance in a…

  20. Hydrogeology of the Azores volcanic archipelago (Portugal)

    Science.gov (United States)

    Cruz, J.; Coutinho, R.; Antunes, P.; Freire, P.

    2009-04-01

    The archipelago of the Azores is made of nine islands of volcanic origin located in the North Atlantic Ocean, with an area of 2333 km2 and approximately 237500 inhabitants, which are 98% dependant from groundwater sources for their water consumption. Therefore, groundwater is a resource that plays a vital role as drinking water source and as ecosystem support matrix. Nevertheless, besides the environmental, social and economical value of groundwater, this resource is subject to an increase pressure and in several islands water quality deterioration is shown by monitoring data. This pressure is also shown by the 42.7% increase expected for domestic use until the year 2020 at the Azores, with higher groundwater abstraction. The Azores climate can be considered as marine temperate, which is reflected by the low thermal amplitude and high precipitation. A well-established difference between a dry season and a colder and wet season occurs, as from October to March about 75% of the annual precipitation is registered. The average annual precipitation at the Azores is 1930 mm, exceeding by far the average annual actual evapotranspiration, which is 581 mm. Recharge rates range from 8.5% to 62.1%, and the highest values are observed at Pico, Terceira, Faial, São Miguel and Graciosa islands, especially in areas where the terrain is covered by recent basaltic lava flows and the soil cover is sparse. Groundwater resources estimates point to a total volume of about 1600x106 m3/yr. Values above the recharge median, equal to 101.3x106 m3/yr. were estimated for the São Miguel, São Jorge, Terceira and Flores islands. Despite differences in the islands growth, as a result of successive volcanic eruptions of various types, groundwater occurrence can be described in function of two main aquifers systems: (1) the basal aquifer system, which corresponds to fresh-water lenses floating on underlying salt water, and (2) perched-water bodies, which are usually drained by springs spread in

  1. Global View of the Arctic Ocean

    Science.gov (United States)

    2000-01-01

    -lapsed view of this remote and inhospitable region. So far, they have processed one season's worth of images. 'We can see large cracks in the ice cover, where most ice grows, ' said Kwok. 'These cracks are much longer than previously thought, some as long as 2,000 kilometers (1,200 miles),' Kwok continued. 'If the ice is thinning due to warming, we'll expect to see more of these long cracks over the Arctic Ocean. 'Scientists believe this is one of the most significant breakthroughs in the last two decades of ice research. 'We are now in a position to better understand the sea ice cover and the role of the Arctic Ocean in global climate change, ' said Kwok.Radar can see through clouds and any kind of weather system, day or night, and as the Arctic regions are usually cloud-covered and subject to long, dark winters, radar is proving to be extremely useful. However, compiling these data into extremely detailed pictures of the Arctic is a challenging task. 'This is truly a major innovation in terms of the quantities of data being processed and the novelty of the methods being used, ' said Verne Kaupp, director of the Alaska SAR Facility at the University of Alaska, Fairbanks.The mission is a joint project between JPL, the Alaska SAR Facility, and the Canadian Space Agency. Launched by NASA in 1995, the Radarsat satellite is operated by the Canadian Space Agency. JPL manages the Sea Ice Thickness Derived From High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced changes affect our global environment.

  2. Bilingualism: A Canadian Challenge

    OpenAIRE

    Shapiro, Bernard J.

    2010-01-01

    Bilingualism in French and English is a much-to-be hoped for common and shared characteristic of Canadian citizenship—even though to date the effect of forty years of the Official Languages Act has been most marked in government services and among various Canadian elites. Although it is important that Canada hold onto a goal of the widest possible bilingualism,more modest objectives are outlined for the years immediately ahead.

  3. Canadian advanced life support capacities and future directions

    Science.gov (United States)

    Bamsey, M.; Graham, T.; Stasiak, M.; Berinstain, A.; Scott, A.; Vuk, T. Rondeau; Dixon, M.

    2009-07-01

    Canada began research on space-relevant biological life support systems in the early 1990s. Since that time Canadian capabilities have grown tremendously, placing Canada among the emerging leaders in biological life support systems. The rapid growth of Canadian expertise has been the result of several factors including a large and technically sophisticated greenhouse sector which successfully operates under challenging climatic conditions, well planned technology transfer strategies between the academic and industrial sectors, and a strong emphasis on international research collaborations. Recent activities such as Canada's contribution of the Higher Plant Compartment of the European Space Agency's MELiSSA Pilot Plant and the remote operation of the Arthur Clarke Mars Greenhouse in the Canadian High Arctic continue to demonstrate Canadian capabilities with direct applicability to advanced life support systems. There is also a significant latent potential within Canadian institutions and organizations with respect to directly applicable advanced life support technologies. These directly applicable research interests include such areas as horticultural management strategies (for candidate crops), growth media, food processing, water management, atmosphere management, energy management, waste management, imaging, environment sensors, thermal control, lighting systems, robotics, command and data handling, communications systems, structures, in-situ resource utilization, space analogues and mission operations. With this background and in collaboration with the Canadian aerospace industry sector, a roadmap for future life support contributions is presented here. This roadmap targets an objective of at least 50% food closure by 2050 (providing greater closure in oxygen, water recycling and carbon dioxide uptake). The Canadian advanced life support community has chosen to focus on lunar surface infrastructure and not low Earth orbit or transit systems (i.e. microgravity

  4. The expedition ARCTIC `96 of RV `Polarstern` (ARK XII) with the Arctic Climate System Study (ACSYS). Cruise report; Die Expedition ARCTIC `96 des FS `Polarstern` (ARK XII) mit der Arctic Climate System Study (ACSYS). Fahrtbericht

    Energy Technology Data Exchange (ETDEWEB)

    Augstein, E.

    1997-11-01

    The multinational expedition ARCTIC `96 was carried out jointly by two ships, the German RV POLARSTERN and the Swedish RV ODEN. The research programme was developed by scientists from British, Canadian, Finish, German, Irish, Norwegian, Russian, Swedish and US American research institutions and universities. The physical programme on POLARSTERN was primarily designed to foster the Arctic Climte System Study (ACSYS) in the framework of the World Climate Research Programme (WCRP). Investigations during the recent years have provided substantial evidence that the Arctic Ocean and the adjacent shelf seas play a significant role in the thermohaline oceanic circulation and may therefore have a distinct influence on global climate. Consequently the main ACSYS goals are concerned with studies of the governing oceanic, atmospheric and hydrological processes in the entire Arctic region. (orig.) [Deutsch] Die Expedition ARCTIC `96 wurde von zwei Forschungsschiffen, der deutschen POLARSTERN und der schwedischen ODEN unter Beteiligung von Wissenschaftlern und Technikern aus Deutschland, Finnland, Grossbritannien, Irland, Kanada, Norwegen, Russland, Schweden und den Vereinigten Staaten von Amerika durchgefuehrt. Die physikalischen Projekte auf der POLARSTERN dienten ueberwiegend der Unterstuetzung der Arctic Climate System Study (ACSYS) des Weltklimaforschungsprogramms, die auf die Erforschung der vorherrschenden ozeanischen, atmosphaerischen, kryosphaerischen und hydrologischen Prozesse der Arktisregion ausgerichtet ist. (orig.)

  5. Arctic Climate Tipping Points

    OpenAIRE

    Lenton, Timothy M.

    2012-01-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the A...

  6. Oceanographic Aspects of Recent Changes in the Arctic

    Science.gov (United States)

    Morison, J. H.

    2002-12-01

    In the Arctic recent decadal-scale changes have marked the atmosphere, ocean, and land. Connections between the oceanographic changes and large-scale atmospheric circulation changes are emerging. Surface atmospheric pressure has shown a declining trend over the Arctic. In the 1990s, the Arctic Ocean circulation took on a more cyclonic character, and the front separating Atlantic-derived waters of the Eurasian Basin and the Pacific-derived waters of the Canadian Basin shifted counterclockwise. The temperature of Atlantic water in the Arctic Ocean reached record levels. The cold halocline, which isolates the surface from the warm Atlantic water, grew thinner disappearing entirely from the Amundsen Basin at one point [Steele and Boyd, 1998]. Arctic sea ice extent has decreased 3% per decade since the 1970s [Parkinson et al., 1999]. Sea ice thickness over much of the Arctic decreased 43% between 1958-1976 and 1993-1997 [Rothrock et al., 1999]. Arctic ecosystems have responded to these changes. Sea ice studies in the late 1990s indicate that the sea ice algal species composition changed from decades before, with the species recently being characterized by more brackish and freshwater forms. Barents Sea fisheries have shifted north following reductions in ice extent. Pacific salmon species have been found entering rivers in the Arctic. There is evidence that this complex of pan-Arctic changes is connected with the rising trend in the Arctic Oscillation (AO) or Northern Hemisphere atmospheric polar vortex in the 1990s. Theoretical evidence that a positive trend in the AO index might be indicative of greenhouse warming raises the possibility that the recent complex of changes is an Arctic characteristic of global climate change. Also, the changes in ice cover manifest a connection between the complex of change and global climate through ice-albedo feedback, by which reductions in ice cover reduce the amount of sunlight reflected from the earth's surface. Another important

  7. Arctic wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E. [Kemijoki Oy (Finland); Holttinen, H.; Marjaniemi, M. [VTT Energy, Espoo (Finland); Tammelin, B. [Finnish Meteorological Institute, Helsinki (Finland)

    1998-12-31

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  8. Arctic wind energy

    International Nuclear Information System (INIS)

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  9. Sea Ice Melt Pond Data from the Canadian Arctic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains observations of albedo, depth, and physical characteristics of melt ponds on sea ice, taken during the summer of 1994. The melt ponds studied...

  10. Astronomical Sky Quality Near Eureka, in the Canadian High Arctic

    CERN Document Server

    Steinbring, Eric; Drummond, James R

    2011-01-01

    Nighttime visible-light sky brightness and transparency are reported for the Polar Environment Research Laboratory (PEARL), located on a 610-m high ridge near the Eureka research station, on Ellesmere Island, Canada. Photometry of Polaris obtained in V band with the PEARL All Sky Imager (PASI) over two winters is supported by standard meteorological measurements and visual estimates of sky conditions from sea level. These data show that during the period of the study, October through March of 2008/09 and 2009/10, the sky near zenith had a mean surface brightness of 19.7 mag/square-arcsec when the sun was more than 12 deg below the horizon, reaching 20.7 mag/square-arcsec during astronomical darkness with no moon. Skies were without thick cloud and potentially usable for astronomy 86% of the time (extinction <2 mag). Up to 68% of the time was spectroscopic (<0.5 mag), attenuated by ice crystals, or clear with stable atmospheric transparency. Those conditions can persist for over 100 hours at a time. Furt...

  11. Summer mesozooplankton community of Moller Bay (Novaya Zemlya Archipelago, Barents Sea

    Directory of Open Access Journals (Sweden)

    A. G. Dvoretsky

    2013-02-01

    Full Text Available Novaya Zemlya Archipelago is the eastern boundary of the Barents Sea. Theplankton of this region have been less intensively studied than thoseof other Arctic areas. This study of the mesozooplankton assemblage of Moller Bay was conducted in August2010. The total mesozooplankton abundance and biomass ranged from 962to 2980 individuals m-3 (mean ± SD: 2263 ± 921 indiv.m-3 and from 12.3 to 456.6 mg dry mass m-3 (mean ± SD:192 ± 170 DM m-3 respectively. Copepods and appendicularians werethe most numerous groups with Oithona similis, Pseudocalanusspp.,Acartiaspp., Calanus glacialis and Oikopleura vanhoeffennibeing the most abundant and frequent. Mesozooplankton abundance tendedto decrease with depth, whereas an inverse pattern was observed for the totalbiomass. Total mesozooplankton biomass was negatively correlated with watertemperature and positively correlated with salinity and chlorophyll aconcentration. Comparison with previous data showed significant interannualvariations in the total zooplankton stock in this region that may be due todifferences in sampling seasons, climatic conditions and the distribution ofpotential food sources (phytoplankton and seabird colonies.

  12. Canadian competitive advantage

    International Nuclear Information System (INIS)

    The evolution of the Canadian petrochemical industry was outlined, emphasizing the proximity to feedstocks as the principal advantage enjoyed by the industry over its international competitors. Annual sales statistics for 1995 were provided. Key players in the Canadian petrochemical industry (Nova, Dow, DuPont, Methanex, Esso, Union Carbide, Shell and Celanese), their share of the market and key products were noted. Manufacturing facilities are located primarily in Alberta, southern Ontario and Quebec. The feedstock supply infrastructure, historical and alternative ethane pricing in Canada and the US, the North American market for petrochemicals, the competitiveness of the industry, tax competitiveness among Canadian provinces and the US, the Canada - US unit labour cost ratio, ethylene facility construction costs in Canada relative to the US Gulf Coast, and projected 1997 financial requirements were reviewed. 19 figs

  13. White Arctic vs. Blue Arctic: Making Choices

    Science.gov (United States)

    Pfirman, S. L.; Newton, R.; Schlosser, P.; Pomerance, R.; Tremblay, B.; Murray, M. S.; Gerrard, M.

    2015-12-01

    As the Arctic warms and shifts from icy white to watery blue and resource-rich, tension is arising between the desire to restore and sustain an ice-covered Arctic and stakeholder communities that hope to benefit from an open Arctic Ocean. If emissions of greenhouse gases to the atmosphere continue on their present trend, most of the summer sea ice cover is projected to be gone by mid-century, i.e., by the time that few if any interventions could be in place to restore it. There are many local as well as global reasons for ice restoration, including for example, preserving the Arctic's reflectivity, sustaining critical habitat, and maintaining cultural traditions. However, due to challenges in implementing interventions, it may take decades before summer sea ice would begin to return. This means that future generations would be faced with bringing sea ice back into regions where they have not experienced it before. While there is likely to be interest in taking action to restore ice for the local, regional, and global services it provides, there is also interest in the economic advancement that open access brings. Dealing with these emerging issues and new combinations of stakeholders needs new approaches - yet environmental change in the Arctic is proceeding quickly and will force the issues sooner rather than later. In this contribution we examine challenges, opportunities, and responsibilities related to exploring options for restoring Arctic sea ice and potential pathways for their implementation. Negotiating responses involves international strategic considerations including security and governance, meaning that along with local communities, state decision-makers, and commercial interests, national governments will have to play central roles. While these issues are currently playing out in the Arctic, similar tensions are also emerging in other regions.

  14. Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves

    Directory of Open Access Journals (Sweden)

    M. Chierici

    2009-05-01

    Full Text Available In the summer of 2005, we sampled surface water and measured pH and total alkalinity (AT underway aboard IB Oden along the Northwest Passage from Cape Farwell (South Greenland to the Chukchi Sea. We investigated variability of carbonate system parameters, focusing particularly on carbonate concentration [CO32−] and calcium carbonate saturation states, as related to freshwater addition, biological processes and physical upwelling. Measurements on AT, pH at 15°C, salinity (S and sea surface temperature (SST, were used to calculate total dissolved inorganic carbon (DIC, [CO32−] and saturation of aragonite (ΩAr and calcite (ΩCa in the surface water. The same parameters were measured in the water column of the Bering Strait. Some surface waters in the Canadian Arctic Archipelago (CAA and on the Mackenzie shelf (MS were found to be undersaturated with respect to aragonite (ΩAr<1. In these areas, surface water was low in AT and DIC (<1500 μmol kg−1 relative to seawater and showed low [CO32−]. The low saturation states were probably due to the effect of dilution due from freshwater addition by sea ice melt (CAA and river runoff (MS. High AT and DIC and low pH, corresponded with the lowest [CO32−], ΩAr and ΩCa, observed near Cape Bathurst and along the South Chukchi Peninsula. This was linked to physical upwelling of subsurface water with elevated CO2. Highest surface ΩAr and ΩCa of 3.0 and 4.5, respectively, were found on the Chukchi Sea shelf and in the cold water north of Wrangel Island, which is heavily influenced by high CO2 drawdown and lower DIC from intense biological production. In the western Bering Strait, the cold and saline Anadyr Current carries water that is enriched in AT and DIC from enhanced organic matter remineralization, resulting in

  15. Canadian Irradiation Centre

    International Nuclear Information System (INIS)

    The Canadian Irradiation Centre is a non-profit cooperative project between Atomic Energy of Canada Limited, Radiochemical Company and Universite du Quebec, Institut Armand-Frappier, Centre for Applied Research in Food Science. The Centre's objectives are to develop, demonstrate and promote Canada's radiation processing technology and its applications by conducting applied research; training technical, professional and scientific personnel; educating industry and government; demonstrating operational and scientific procedures; developing processing procedures and standards, and performing product and market acceptance trials. This pamphlet outlines the history of radoation technology and the services offered by the Canadian Irradiation Centre

  16. Canadian beef quality audit.

    OpenAIRE

    Van Donkersgoed, J; Jewison, G; M. Mann; Cherry, B; Altwasser, B; Lower, R; Wiggins, K; Dejonge, R; Thorlakson, B; Moss, E.; C. Mills; Grogan, H

    1997-01-01

    A study was conducted in 4 Canadian processing plants in 1995-96 to determine the prevalence of quality defects in Canadian cattle. One percent of the annual number of cattle processed in Canada were evaluated on the processing floor and 0.1% were graded in the cooler. Brands were observed on 37% and multiple brands on 6% of the cattle. Forty percent of the cattle had horns, 20% of which were scurs, 33% were stubs, 10% were tipped, and 37% were full length. Tag (mud and manure on the hide) wa...

  17. Sensitivity of CryoSat-2 Arctic sea-ice volume trends on radar-waveform interpretation

    Directory of Open Access Journals (Sweden)

    R. Ricker

    2014-04-01

    other published studies. Using the selected retrackers we evaluate the uncertainties of trends in sea-ice freeboard and higher level products that arise from the choice of the retracker threshold only, independently from the uncertainties related to snow and ice properties. Our study shows that the choice of retracker thresholds does have a non-negligible impact on magnitude estimates of sea-ice freeboard, thickness and volume, but that the main trends in these parameters are less affected. Specifically we find declines of Arctic sea-ice volume of 9.7% (40% threshold, 10.9% (50% threshold and 6.9% (80% threshold between March 2011 and March 2013. In contrast to that we find increases in Arctic sea-ice volume of 27.88% (40% threshold, 25.71% (50% threshold and 32.65% (80% threshold between November 2011 and November 2013. Furthermore we obtain a significant increase of freeboard from March 2013 to November 2013 in the area for multi-seasonal sea-ice north of Greenland and the Canadian Archipelago. Since this is unlikely it gives rise to the assumption that applying different retracker thresholds depending on seasonal properties of the snow load is necessary in the future.

  18. Sponge interactions with spatial competitors in the Spermonde Archipelago

    NARCIS (Netherlands)

    Voogd, de N.J.; Becking, L.E.; Hoeksema, B.W.; Noor, A.; Soest, van R.W.M.

    2003-01-01

    This study describes the in situ effects of four bioactive sponges on their neighbours at three different locations and two depths in the Spermonde Archipelago, SW Sulawesi, Indonesia. The natural rates of interaction between the sponge species and eight possible competitive invertebrate groups were

  19. Larger Foraminifera from the Spermonde Archipelago (Sulawesi, Indonesia)

    NARCIS (Netherlands)

    Troelstra, S.R.; Jonkers, H.M.; Rijk, de S.

    1996-01-01

    A systematic description of the distributional patterns of larger symbiont-bearing benthic Foraminifera from the Spermonde Archipelago (Sulawesi, Indonesia) and their relation with local coral reef growth is presented. The larger Foraminiferal assemblages and diversity indices correspond with the di

  20. Myxozoa in high Arctic: Survey on the central part of Svalbard archipelago

    Czech Academy of Sciences Publication Activity Database

    Kodádková, Alena; Dyková, I.; Tyml, Tomáš; Ditrich, O.; Fiala, Ivan

    2014-01-01

    Roč. 3, č. 1 (2014), s. 41-56. ISSN 2213-2244 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Artic * Marine urinary clade * Myxosporea * Phylogeny * Schulmania * Zschokkella Subject RIV: EG - Zoology

  1. The fate of lake ice in the North American Arctic

    Directory of Open Access Journals (Sweden)

    L. C. Brown

    2011-10-01

    Full Text Available Lakes comprise a large portion of the surface cover in northern North America, forming an important part of the cryosphere. The timing of lake ice phenological events (e.g. break-up/freeze-up is a useful indicator of climate variability and change, which is of particular relevance in environmentally sensitive areas such as the North American Arctic. Further alterations to the present day ice regime could result in major ecosystem changes, such as species shifts and the disappearance of perennial ice cover. The Canadian Lake Ice Model (CLIMo was used to simulate lake ice phenology across the North American Arctic from 1961–2100 using two climate scenarios produced by the Canadian Regional Climate Model (CRCM. Results from the 1961–1990 time period were validated using 15 locations across the Canadian Arctic, with both in situ ice cover observations from the Canadian Ice Database as well as additional ice cover simulations using nearby weather station data. Projected changes to the ice cover using the 30-year mean data between 1961–1990 and 2041–2070 suggest a shift in break-up and freeze-up dates for most areas ranging from 10–25 days earlier (break-up and 0–15 days later (freeze-up. The resulting ice cover durations show mainly a 10–25 day reduction for the shallower lakes (3 and 10 m and 10–30 day reduction for the deeper lakes (30 m. More extreme reductions of up to 60 days (excluding the loss of perennial ice cover were shown in the coastal regions compared to the interior continental areas. The mean maximum ice thickness was shown to decrease by 10–60 cm with no snow cover and 5–50 cm with snow cover on the ice. Snow ice was also shown to increase through most of the study area with the exception of the Alaskan coastal areas.

  2. The fate of lake ice in the North American Arctic

    Directory of Open Access Journals (Sweden)

    L. C. Brown

    2011-07-01

    Full Text Available Lakes comprise a large portion of the surface cover in northern North America forming an important part of the cryosphere. The timing of lake ice phenological events (e.g. break-up/freeze-up are useful indicators of climate variability and change, which is of particular relevance in environmentally sensitive areas such as the North American Arctic. Further alterations to the present day ice regime could result in major ecosystem changes, such as species shifts and the disappearance of perennial ice cover. Lake ice models are a valuable tool for examining the response of lake ice cover to changing climate conditions. The use of future climate scenario data in these models can provide information on the potential changes in ice phenology, ice thickness and composition. The Canadian Lake Ice Model (CLIMo was used to simulate lake ice phenology across the North American Arctic from 1961–2100 using climate scenarios produced by the Canadian Regional Climate Model (CRCM. Results from the 1961–1990 time period were validated using 15 locations across the Canadian Arctic, with both in situ ice cover observations from the Canadian Ice Database as well as additional ice cover simulations using nearby weather station data. Projected changes to the ice cover using the 30 yr mean data between 1961–1990 and 2041–2070 suggest a shift towards shorter ice cover durations by an average of just over 3 weeks, with a 25 cm average reduction of the total ice thickness – varying based on location, lake depth and snow cover amounts.

  3. Canada : oil, gas, and the new Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Huebert, R. [Calgary Univ., AB (Canada). Dept. of Political Science; Calgary Univ., AB (Canada). Centre for Military and Strategic Studies

    2010-07-01

    This presentation provided a broad overview of the geopolitical issues affecting the massive transformation of the Arctic resulting from resource development, globalization, and climate change. Two Arctics are emerging, notably one European and one North American. Oil and gas companies are investing heavily in the North, and there is continued debate over pipelines and projects, but the viability of projects can shift abruptly from technological and political change. Recent examples include the emergence of shale gas, the possibility of the United States becoming a gas exporter, and the Deepwater Horizon disaster. In terms of Maritime jurisdictions and boundaries, a comparison was presented regarding the Canadian and Russian claims to the continental shelf. International cooperation and a commitment to peaceful means can be seen in the Ilulissat Declaration, the acceptance of the United Nations Convention of the Law of the Sea as rules, the scientific cooperation of Canada, the United States, and Denmark, and the recent boundary agreement between Russia and Norway. The positions of the main players in the new geopolitics of the North were outlined, particularly with respect to Russia, the United States, Norway, Denmark, and Canada. Their recent policy statements and developing arctic force capabilities were summarized. Canada's more assertive Arctic policy was outlined in more detail along with the country's base locations and recent security actions in the North. The main issues facing nations with interests in the North will be maritime and aerospace; understanding the new players on the scene; and new technological developments. 10 figs., 5 refs.

  4. Canadian heavy water production

    International Nuclear Information System (INIS)

    The paper reviews Canadian experience in the production of heavy water, presents a long-term supply projection, relates this projection to the anticipated long-term electrical energy demand, and highlights principal areas for further improvement that form the bulk of our research and development program on heavy water processes

  5. Canadian hydrogen safety program

    International Nuclear Information System (INIS)

    The Canadian hydrogen safety program (CHSP) is a project initiative of the Codes and Standards Working Group of the Canadian transportation fuel cell alliance (CTFCA) that represents industry, academia, government, and regulators. The Program rationale, structure and contents contribute to acceptance of the products, services and systems of the Canadian Hydrogen Industry into the Canadian hydrogen stakeholder community. It facilitates trade through fair insurance policies and rates, effective and efficient regulatory approval procedures and accommodation of the interests of the general public. The Program integrates a consistent quantitative risk assessment methodology with experimental (destructive and non-destructive) failure rates and consequence-of-release data for key hydrogen components and systems into risk assessment of commercial application scenarios. Its current and past six projects include Intelligent Virtual Hydrogen Filling Station (IVHFS), Hydrogen clearance distances, comparative quantitative risk comparison of hydrogen and compressed natural gas (CNG) refuelling options; computational fluid dynamics (CFD) modeling validation, calibration and enhancement; enhancement of frequency and probability analysis, and Consequence analysis of key component failures of hydrogen systems; and fuel cell oxidant outlet hydrogen sensor project. The Program projects are tightly linked with the content of the International Energy Agency (IEA) Task 19 Hydrogen Safety. (author)

  6. Twitter and Canadian Educators

    Science.gov (United States)

    Cooke, Max

    2012-01-01

    An emerging group of leaders in Canadian education has attracted thousands of followers. They've made Twitter an extension of their lives, delivering twenty or more tweets a day that can include, for example, links to media articles, research, new ideas from education bloggers, or to their own, or simply a personal thought. At their best,…

  7. Reform in Canadian Universities.

    Science.gov (United States)

    Small, J. M.

    1994-01-01

    A survey of 67 Canadian university vice presidents and 66 deans concerning reform in recent years found that the many changes reported were modest and reactive rather than bold and proactive. Most common changes involved strategic planning, retrenchment, curriculum expansion, response to enrollment changes, administrative restructuring, and more…

  8. Canadian Red Cross.

    Science.gov (United States)

    Lavender, Colleen

    2008-01-01

    The Canadian Red Cross is guided by its Fundamental Principles--humanity, impartiality, neutrality, independence, voluntary service, unity, and universality--and organized in a traditional geographic hierarchical structure. Among the characteristics that have contributed to its success are a budgeting process that starts at the local level, measurement of program outcomes, and coordinated fundraising activities at the regional level. PMID:18551842

  9. Canadian petroleum industry review

    International Nuclear Information System (INIS)

    A wide ranging discussion about the factors that have influenced oil and natural gas prices, the differences of the Canadian market from international markets, the differences between eastern and western Canadian markets, and shareholders' perspectives on recent commodity price developments was presented. Developments in the OPEC countries were reviewed, noting that current OPEC production of 25 mmbbls is about 60 per cent higher than it was in 1985. It is expected that OPEC countries will continue to expand capacity to meet expected demand growth and the continuing need created by the UN embargo on Iraqi oil sales. Demand for natural gas is also likely to continue to rise especially in view of the deregulation of the electricity industry where natural gas may well become the favored fuel for incremental thermal generation capacity. Prices of both crude oil and natural gas are expected to hold owing to unusually low storage levels of both fuels. The inadequacy of infrastructure, particularly pipeline capacity as a key factor in the Canadian market was noted, along with the dynamic that will emerge in the next several years that may have potential consequences for Canadian production - namely the reversal of the Sarnia to Montreal pipeline. With regard to shareholders' expectations the main issues are (1) whether international markets reach back to the wellhead, hence the producer's positioning with respect to transportation capacity and contract portfolios, and (2) whether the proceeds from increased prices are invested in projects that are yielding more than the cost of capital. 28 figs

  10. Rapid Arctic Changes due to Infrastructure and Climate (RATIC) in the Russian North

    Science.gov (United States)

    Walker, D. A.; Kofinas, G.; Raynolds, M. K.; Kanevskiy, M. Z.; Shur, Y.; Ambrosius, K.; Matyshak, G. V.; Romanovsky, V. E.; Kumpula, T.; Forbes, B. C.; Khukmotov, A.; Leibman, M. O.; Khitun, O.; Lemay, M.; Allard, M.; Lamoureux, S. F.; Bell, T.; Forbes, D. L.; Vincent, W. F.; Kuznetsova, E.; Streletskiy, D. A.; Shiklomanov, N. I.; Fondahl, G.; Petrov, A.; Roy, L. P.; Schweitzer, P.; Buchhorn, M.

    2015-12-01

    The Rapid Arctic Transitions due to Infrastructure and Climate (RATIC) initiative is a forum developed by the International Arctic Science Committee (IASC) Terrestrial, Cryosphere, and Social & Human working groups for developing and sharing new ideas and methods to facilitate the best practices for assessing, responding to, and adaptively managing the cumulative effects of Arctic infrastructure and climate change. An IASC white paper summarizes the activities of two RATIC workshops at the Arctic Change 2014 Conference in Ottawa, Canada and the 2015 Third International Conference on Arctic Research Planning (ICARP III) meeting in Toyama, Japan (Walker & Pierce, ed. 2015). Here we present an overview of the recommendations from several key papers and posters presented at these conferences with a focus on oil and gas infrastructure in the Russian north and comparison with oil development infrastructure in Alaska. These analyses include: (1) the effects of gas- and oilfield activities on the landscapes and the Nenets indigenous reindeer herders of the Yamal Peninsula, Russia; (2) a study of urban infrastructure in the vicinity of Norilsk, Russia, (3) an analysis of the effects of pipeline-related soil warming on trace-gas fluxes in the vicinity of Nadym, Russia, (4) two Canadian initiatives that address multiple aspects of Arctic infrastructure called Arctic Development and Adaptation to Permafrost in Transition (ADAPT) and the ArcticNet Integrated Regional Impact Studies (IRIS), and (5) the effects of oilfield infrastructure on landscapes and permafrost in the Prudhoe Bay region, Alaska.

  11. National Oceanic and Atmospheric Administration(NOAA) Arctic Climate Change Studies: A Contribution to IPY

    Science.gov (United States)

    Calder, J.; Overland, J.; Uttal, T.; Richter-Menge, J.; Rigor, I.; Crane, K.

    2004-12-01

    NOAA has initiated four activities that respond to the Arctic Climate Impact Assessment(ACIA) recommendations and represent contributions toward the IPY: 1) Arctic cloud, radiation and aerosol observatories, 2) documentation and attribution of changes in sea-ice thickness through direct measurement and modeling, 3) deriving added value from existing multivariate and historical data, and 4) following physical and biological changes in the northern Bering and Chukchi Seas. Northeast Canada, the central Arctic coast of Russia and the continuing site at Barrow have been chosen as desirable radiation/cloud locations as they exhibit different responses to Arctic Oscillation variability. NOAA is closely collaborating with Canadian groups to establish an observatory at Eureka. NOAA has begun deployment of a network of ice-tethered ice mass balance buoys complemented by several ice profiling sonars. In combination with other sea ice investigators, the Arctic buoy program, and satellites, changes can be monitored more effectively in sea ice throughout the Arctic. Retrospective data analyses includes analysis of Arctic clouds and radiation from surface and satellite measurements, correction of systematic errors in TOVS radiance data sets for the Arctic which began in 1979, addressing the feasibility of an Arctic System Reanalysis, and an Arctic Change Detection project that incorporates historical and recent physical and biological observations and news items at a website, www.arctic.noaa.gov. NOAA has begun a long-term effort to detect change in ecosystem indicators in the northern Bering and Chukchi Seas that could provide a model for other northern marine ecosystems. The first efforts were undertaken in summer 2004 during a joint Russian-US cruise that mapped the regions physical, chemical and biological parameters to set the stage for future operations over the longer term. A line of biophysical moorings provide detection of the expected warming of this area. A

  12. Arctic Climate Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ivey, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robinson, David G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boslough, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Peterson, Kara J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); van Bloemen Waanders, Bart G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Swiler, Laura Painton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Desilets, Darin Maurice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reinert, Rhonda Karen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    This study began with a challenge from program area managers at Sandia National Laboratories to technical staff in the energy, climate, and infrastructure security areas: apply a systems-level perspective to existing science and technology program areas in order to determine technology gaps, identify new technical capabilities at Sandia that could be applied to these areas, and identify opportunities for innovation. The Arctic was selected as one of these areas for systems level analyses, and this report documents the results. In this study, an emphasis was placed on the arctic atmosphere since Sandia has been active in atmospheric research in the Arctic since 1997. This study begins with a discussion of the challenges and benefits of analyzing the Arctic as a system. It goes on to discuss current and future needs of the defense, scientific, energy, and intelligence communities for more comprehensive data products related to the Arctic; assess the current state of atmospheric measurement resources available for the Arctic; and explain how the capabilities at Sandia National Laboratories can be used to address the identified technological, data, and modeling needs of the defense, scientific, energy, and intelligence communities for Arctic support.

  13. Impact of aerosol emission controls on future Arctic sea ice cover

    Science.gov (United States)

    Gagné, M.-È.; Gillett, N. P.; Fyfe, J. C.

    2015-10-01

    We examine the response of Arctic sea ice to projected aerosol and aerosol precursor emission changes under the Representative Concentration Pathway (RCP) scenarios in simulations of the Canadian Earth System Model. The overall decrease in aerosol loading causes a warming, largest over the Arctic, which leads to an annual mean reduction in sea ice extent of approximately 1 million km2 over the 21st century in all RCP scenarios. This accounts for approximately 25% of the simulated reduction in sea ice extent in RCP 4.5, and 40% of the reduction in RCP 2.5. In RCP 4.5, the Arctic ocean is projected to become ice-free during summertime in 2045, but it does not become ice-free until 2057 in simulations with aerosol precursor emissions held fixed at 2000 values. Thus, while reductions in aerosol emissions have significant health and environmental benefits, their substantial contribution to projected Arctic climate change should not be overlooked.

  14. Canadian fusion program

    International Nuclear Information System (INIS)

    The National Research Council of Canada is establishing a coordinated national program of fusion research and development that is planned to grow to a total annual operating level of about $20 million in 1985. The long-term objective of the program is to put Canadian industry in a position to manufacture sub-systems and components of fusion power reactors. In the near term the program is designed to establish a minimum base of scientific and technical expertise sufficient to make recognized contributions and thereby gain access to the international effort. The Canadian program must be narrowly focussed on a few specializations where Canada has special indigenous skills or technologies. The programs being funded are the Tokamak de Varennes, the Fusion Fuels Technology Project centered on tritium management, and high-power gas laser technology and associated diagnostic instrumentation

  15. Canadian acid rain policy

    International Nuclear Information System (INIS)

    On March 13 of 1991, the Prime Minister of Canada, Brian Mulroney and the President of the United States of America, George Bush, signed an Agreement on Air Quality. This agreement enshrines Principle 21 of the 1972 Stockholm Declaration which states that countries are to ensure that activities within their jurisdiction do not cause damage to the environment of another country. This agreement also includes provisions for controlling acid rain. The Agreement on Air Quality followed years of discussion between the two countries and is a significant milestone in the history of Canadian acid rain policy. This paper begins by describing Canadian acid rain policy and its evolution. The paper also outlines the Canada-United States Air Quality Agreement and the effect of the acid rain provisions on deposition in Canada. Finally, it considers the future work that must be undertaken to further resolve the acid rain problem. 8 refs., 5 figs., 1 tab

  16. Canadian Mathematical Congress

    CERN Document Server

    1977-01-01

    For two weeks in August, 1975 more than 140 mathematicians and other scientists gathered at the Universite de Sherbrooke. The occasion was the 15th Biennial Seminar of the Canadian Mathematical Congress, entitled Mathematics and the Life Sciences. Participants in this inter­ disciplinary gathering included researchers and graduate students in mathematics, seven different areas of biological science, physics, chemistry and medical science. Geographically, those present came from the United States and the United Kingdom as well as from academic departments and government agencies scattered across Canada. In choosing this particular interdisciplinary topic the programme committee had two chief objectives. These were to promote Canadian research in mathematical problems of the life sciences, and to encourage co-operation and exchanges between mathematical scientists" biologists and medical re­ searchers. To accomplish these objective the committee assembled a stim­ ulating programme of lectures and talks. Six ...

  17. Financing Canadian international operations

    International Nuclear Information System (INIS)

    A primer on financing international operations by Canadian corporations was provided. Factors affecting the availability to project finance (location, political risk), the various forms of financing (debt, equity, and combinations), the main sources of government backed financing to corporations (the International Finance Corporation) (IFC), the European Bank for Reconstruction and Development (EBRD), the Asian Development Bank (ADB), the Overseas Property Insurance Corporation (OPIC), government or agency guarantees, political risk coverage, the use of offshore financial centres, and the where, when and how these various organizations operate, were reviewed. Examples of all of the above, taken from the experiences of Canadian Occidental Petroleum of Calgary in the U.S., in South America, in the Middle and Far East, and in Kazakhstan, were used as illustrations. figs

  18. Canadian petroleum history bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Cass, D.

    2003-09-27

    The Petroleum History Bibliography includes a list of more than 2,000 publications that record the history of the Canadian petroleum industry. The list includes books, theses, films, audio tapes, published articles, company histories, biographies, autobiographies, fiction, poetry, humour, and an author index. It was created over a period of several years to help with projects at the Petroleum History Society. It is an ongoing piece of work, and as such, invites comments and additions.

  19. Coexistence of reef organisms in the Abrolhos Archipelago, Brazil.

    Science.gov (United States)

    Lins de Barros, M M; Castro, C B; Pires, D O; Segal, B

    2000-12-01

    The first study on coexistence of reef benthic organisms in Brazilian coral reefs was done in three localities of the Abrolhos Archipelago. Organisms were recorded in concentric circle samples (10 and 20 cm in diameter) randomly laid on transects. Type and frequency of "coexistence events" between pairs of organisms were determined. Most frequent organisms (massive and branched coralline algae, Favia gravida, and Agaricia agaricites) also had many significant positive coexistence events. These results might be related to the abundances of these organisms. The most frequent coral (Siderastrea stellata), however, exhibited only a few significant coexistence events (9% of 32 tests). Since the great majority of events were positive, and since there was high variation in the species/groups involved in significant events in different localities, benthic communities of Abrolhos Archipelago may well be structured primarily by abiotic rather than biotic factors. PMID:11487922

  20. Arctic Shipping Emissions in the Changing Climate

    OpenAIRE

    Vihanninjoki, Vesa

    2014-01-01

    Due to the Arctic climate change and the related diminishing of Arctic sea ice cover, the general conditions for Arctic shipping are changing. The retreat of Arctic sea ice opens up new routes for maritime transportation, both trans-Arctic passages and new alternatives within the Arctic region. Hence the amount of Arctic shipping is presumed to increase. Despite the observed development, the sailing conditions in the Arctic waters will remain challenging. Thus particular attention will be ...

  1. Tuberculosis in Aboriginal Canadians

    Directory of Open Access Journals (Sweden)

    Vernon H Hoeppner

    2000-01-01

    Full Text Available Endemic tuberculosis (TB was almost certainly present in Canadian aboriginal people (aboriginal Canadians denotes status Indians, Inuit, nonstatus Indians and metis as reported by Statistics Canada before the Old World traders arrived. However, the social changes that resulted from contact with these traders created the conditions that converted endemic TB into epidemic TB. The incidence of TB varied inversely with the time interval from this cultural collision, which began on the east coast in the 16th century and ended in the Northern Territories in the 20th century. This relatively recent epidemic explains why the disease is more frequent in aboriginal children than in Canadian-born nonaboriginal people. Treatment plans must account for the socioeconomic conditions and cultural characteristics of the aboriginal people, especially healing models and language. Prevention includes bacillus Calmette-Guerin vaccination and chemoprophylaxis, and must account for community conditions, such as rates of suicide, which have exceeded the rate of TB. The control of TB requires a centralized program with specifically directed funding. It must include a program that works in partnership with aboriginal communities.

  2. Arctic Bathymetry (batharcst)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The digitally compiled map includes geology, oil and gas field centerpoints, and geologic provinces of the Arctic (North Pole area encircled by 640 N Latitude). The...

  3. Live from the Arctic

    Science.gov (United States)

    Warnick, W. K.; Haines-Stiles, G.; Warburton, J.; Sunwood, K.

    2003-12-01

    For reasons of geography and geophysics, the poles of our planet, the Arctic and Antarctica, are places where climate change appears first: they are global canaries in the mine shaft. But while Antarctica (its penguins and ozone hole, for example) has been relatively well-documented in recent books, TV programs and journalism, the far North has received somewhat less attention. This project builds on and advances what has been done to date to share the people, places, and stories of the North with all Americans through multiple media, over several years. In a collaborative project between the Arctic Research Consortium of the United States (ARCUS) and PASSPORT TO KNOWLEDGE, Live from the Arctic will bring the Arctic environment to the public through a series of primetime broadcasts, live and taped programming, interactive virtual field trips, and webcasts. The five-year project will culminate during the 2007-2008 International Polar Year (IPY). Live from the Arctic will: A. Promote global understanding about the value and world -wide significance of the Arctic, B. Bring cutting-edge research to both non-formal and formal education communities, C. Provide opportunities for collaboration between arctic scientists, arctic communities, and the general public. Content will focus on the following four themes. 1. Pan-Arctic Changes and Impacts on Land (i.e. snow cover; permafrost; glaciers; hydrology; species composition, distribution, and abundance; subsistence harvesting) 2. Pan-Arctic Changes and Impacts in the Sea (i.e. salinity, temperature, currents, nutrients, sea ice, marine ecosystems (including people, marine mammals and fisheries) 3. Pan-Arctic Changes and Impacts in the Atmosphere (i.e. precipitation and evaporation; effects on humans and their communities) 4. Global Perspectives (i.e. effects on humans and communities, impacts to rest of the world) In The Earth is Faster Now, a recent collection of comments by members of indigenous arctic peoples, arctic

  4. Arctic_Bathymetry

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Models project the Arctic Ocean will become undersaturated with respect to carbonate minerals in the next decade. Recent field results indicate parts may already be...

  5. Arctic survey, 1957

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey and game patrol conducted to twelve villages in the Arctic from April 24 to May 2 1957. The report covers animals take for income...

  6. Arctic Geology (geoarcst)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The digitally compiled map includes geology, oil and gas field centerpoints, and geologic provinces of the Arctic (North Pole area encircled by 640 N Latitude). The...

  7. Seismological observations of glaciers dynamic on the Spitsbergen archipelago

    OpenAIRE

    Fedorov A.V.; Asming V. E.; Baranov S. V.; Vinogradov A. N.; Evtyugina Z. A.; Goryunov V. A.

    2016-01-01

    The paper provides a brief description of results of Spitsbergen glacier observations by the seismic method. The study has been carried out both by permanent and temporary stations data. Characteristic features of glacier-related seismic events have been shown. Main areas of glacier seismic activity on the Archipelago have been revealed. A detailed study of Horsund-fjord glacier activity has been carried out using local seismic station HSPB data. Temporal and spatial distributions of glacier-...

  8. Archipelago Tidal Flats in Korea: Sedimentological and Geoheritage Significance

    Science.gov (United States)

    Woo, Kyung Sik; Chun, SeungSoo; Moon, Kyong O.

    2015-04-01

    Over one thousand islands with rocky shores are distributed and concentrated along the southwestern coast of the Korean Peninsula. Various tidal flats formed along the rocky coasts of the archipelago have been developed due to the relative decrease in accommodation space by slow sea-level rise on broad marginal epicontinental seas during the Holocene. Sedimentation and evolution on these archipelago tidal flats (ATF) show quite distinctive and various tidal flat patterns, depending upon the location and direction of rocky shores which have been constantly influenced by monsoon winds reversely changing with season. Generally ATF is characterized by surrounding wave-dominated sand flats along the outside of the archipelago and by broad tide-dominated mud flats in its central part with spring tidal range reaching up to 6 meters. The open-coast outside sand flats and inner mud flats are completely different in terms of sedimentation and the evolution of sedimentary sequences. The former has been deposited by the transgressive sedimentation with strongly destructive and weakly constructive wave/tide processes, forming relative thin and younger (ca. 3,000 yrs BP) remnant storm-dominated sandflat units. The latter has been deposited by continuous transgressive settling with constructive tidal processes during Holocene, forming relative thick and older (from ca. 7,000 yrs BP) mud-flat units. Geomorphological features and the geological evolution of the ATF (Shinan archipelago and Yoobudo islands in Seocheon) display a quite distinctive pattern of ongoing geological processes from the Wadden Sea tidal flats which was already inscribed as World Natural Heritage. Therefore, the Outstanding Universal Values of the Korean ITF for criteria (vii) and (viii) should provide a strong support for the additional World Natural Heritage Site.

  9. Larger Foraminifera from the Spermonde Archipelago (Sulawesi, Indonesia)

    OpenAIRE

    Troelstra, S. R.; Jonkers, H.M.; Rijk, de, J.

    1996-01-01

    A systematic description of the distributional patterns of larger symbiont-bearing benthic Foraminifera from the Spermonde Archipelago (Sulawesi, Indonesia) and their relation with local coral reef growth is presented. The larger Foraminiferal assemblages and diversity indices correspond with the diversity of Scleractinia and marine plants on the Spermonde platform. Our results indicate that the group is an excellent biomonitor for the health condition of recent coral reefs and a valuable too...

  10. Contribution to the Pteridophyte Flora of Langkawi Archipelago, Peninsular Malaysia.

    Science.gov (United States)

    Maideen, Haja; Damanhuri, Ahmad

    2015-12-01

    The pteridophyte flora of Langkawi Archipelago consists of 130 species, 1 subspecies and 12 varieties in 68 genera and 27 families. This value represents 22.1% of the 647 taxa at the species level and below reported for Peninsular Malaysia. Of the 143 recorded taxa of pteridophytes at the species level and below, 8 species in 2 genera and 2 families are lycophytes and the other 135 taxa in 66 genera and 25 families are monilophytes or ferns. PMID:26868714

  11. Predicting Coral Recruitment in Palau’s Complex Reef Archipelago

    OpenAIRE

    Golbuu, Yimnang; Wolanski, Eric; Idechong, Jacques Wasai; Victor, Steven; Isechal, Adelle Lukes; Oldiais, Noelle Wenty; Idip, David; Richmond, Robert H.; van Woesik, Robert

    2012-01-01

    Reproduction and recruitment are key processes that replenish marine populations. Here we use the Palau archipelago, in the western Pacific Ocean, as a case study to examine scales of connectivity and to determine whether an oceanographic model, incorporating the complex reef architecture, is a useful predictor of coral recruitment. We tested the hypothesis that the reefs with the highest retention also had the highest densities of juvenile coral density from 80 field sites. Field comparisons...

  12. Understanding the coastline evolution in the Kerkennah archipelago

    OpenAIRE

    Etienne, Lucile; Daoud, Abdelkarim; Beltrando, Gérard

    2014-01-01

    International audience The Kerkennah archipelago in Tunisia is vulnerable to sea erosion and different marks of coastline retreat indicate that this process is currently active. Our objective is to quantify coastal erosion and to discuss the management of risks along the coastline. For that purpose, we used both photointerpretation and field approaches, and integrated all the collected information into a GIS. The quantification of coastline evolution was done using the Digital Shoreline An...

  13. The Grunts (Family Haemulidae) of the Spermonde Archipelago, South Sulawesi

    OpenAIRE

    Burhanuddin, Andi Iqbal; IWATSUKI, Yukio

    2012-01-01

    Fish diversity monitoring could be utilized as a basis for formulating management regulation of the fisheries resources. These studies were conducted to describe the grunt of the family Haemulidae from the Spermonde Archipelago, South Sulawesi. Specimens were collected in Rajawali and Paotere Fish Landing Port Makassar, South Sulawesi from August 2003 to November 2010. The results showed that there were thirdteen species representing three genera of family Haemulidae inhabiting the area wer...

  14. Landslides density map of S. Miguel Island, Azores archipelago

    OpenAIRE

    Valadão, P.; Gaspar, J. L.; Queiroz, G.; Ferreira, T

    2002-01-01

    The Azores archipelago is located in the Atlantic Ocean and is composed of nine volcanic islands. S. Miguel, the largest one, is formed by three active, E-W trending, trachytic central volcanoes with caldera (Sete Cidades, Fogo and Furnas). Chains of basaltic cinder cones link those major volcanic structures. An inactive trachytic central volcano (Povoação) and an old basaltic volcanic complex (Nordeste) comprise the easternmost part of th...

  15. Arctic root-associated fungal community composition reflects environmental filtering.

    Science.gov (United States)

    Blaalid, Rakel; Davey, Marie L; Kauserud, Håvard; Carlsen, Tor; Halvorsen, Rune; Høiland, Klaus; Eidesen, Pernille B

    2014-02-01

    There is growing evidence that root-associated fungi have important roles in Arctic ecosystems. Here, we assess the diversity of fungal communities associated with roots of the ectomycorrhizal perennial herb Bistorta vivipara on the Arctic archipelago of Svalbard and investigate whether spatial separation and bioclimatic variation are important structuring factors of fungal community composition. We sampled 160 plants of B. vivipara from 32 localities across Svalbard. DNA was extracted from entire root systems, and 454 pyrosequencing of ITS1 amplicons was used to profile the fungal communities. The fungal communities were predominantly composed of Basidiomycota (55% of reads) and Ascomycota (35%), with the orders Thelephorales (24%), Agaricales (13.8%), Pezizales (12.6%) and Sebacinales (11.3%) accounting for most of the reads. Plants from the same site or region had more similar fungal communities to one another than plants from other sites or regions, and sites clustered together along a weak latitudinal gradient. Furthermore, a decrease in per-plant OTU richness with increasing latitude was observed. However, no statistically significant spatial autocorrelation between sites was detected, suggesting that environmental filtering, not dispersal limitation, causes the observed patterns. Our analyses suggest that while latitudinal patterns in community composition and richness might reflect bioclimatic influences at global spatial scales, at the smaller spatial scale of the Svalbard archipelago, these changes more likely reflect varied bedrock composition and associated edaphic factors. The need for further studies focusing on identifying those specific bioclimatic and edaphic factors structuring root-associated fungal community composition at both global and local scales is emphasized. PMID:24320873

  16. Arctic Tourism: Realities & Possibilities

    OpenAIRE

    Pashkevich, Albina

    2014-01-01

    This paper addresses human capital in the Arctic in relation to tourism. More specifically, with an ever-increasing number oftourists recognizing the attractiveness of the Arctic, tour companies are increasingly recognizing the opportunities. The media(typically southern media) sells the image, either before or after the tourists arrive, and communities are often left to deal with therepercussions – whether those are social, economic, environmental, or the like. Many of the repercussions are ...

  17. Arctic freshwater synthesis: Introduction

    Science.gov (United States)

    Prowse, T.; Bring, A.; Mârd, J.; Carmack, E.

    2015-11-01

    In response to a joint request from the World Climate Research Program's Climate and Cryosphere Project, the International Arctic Science Committee, and the Arctic Council's Arctic Monitoring and Assessment Program, an updated scientific assessment has been conducted of the Arctic Freshwater System (AFS), entitled the Arctic Freshwater Synthesis (AFSΣ). The major reason for joint request was an increasing concern that changes to the AFS have produced, and could produce even greater, changes to biogeophysical and socioeconomic systems of special importance to northern residents and also produce extra-Arctic climatic effects that will have global consequences. Hence, the key objective of the AFSΣ was to produce an updated, comprehensive, and integrated review of the structure and function of the entire AFS. The AFSΣ was organized around six key thematic areas: atmosphere, oceans, terrestrial hydrology, terrestrial ecology, resources and modeling, and the review of each coauthored by an international group of scientists and published as separate manuscripts in this special issue of Journal of Geophysical Research-Biogeosciences. This AFSΣ—Introduction reviews the motivations for, and foci of, previous studies of the AFS, discusses criteria used to define the domain of the AFS, and details key characteristics of the definition adopted for the AFSΣ.

  18. The Arctic Visiting Speakers Program

    Science.gov (United States)

    Wiggins, H. V.; Fahnestock, J.

    2013-12-01

    The Arctic Visiting Speakers Program (AVS) is a program of the Arctic Research Consortium of the U.S. (ARCUS) and funded by the National Science Foundation. AVS provides small grants to researchers and other Arctic experts to travel and share their knowledge in communities where they might not otherwise connect. The program aims to: initiate and encourage arctic science education in communities with little exposure to arctic research; increase collaboration among the arctic research community; nurture communication between arctic researchers and community residents; and foster arctic science education at the local level. Individuals, community organizations, and academic organizations can apply to host a speaker. Speakers cover a wide range of arctic topics and can address a variety of audiences including K-12 students, graduate and undergraduate students, and the general public. Preference is given to tours that reach broad and varied audiences, especially those targeted to underserved populations. Between October 2000 and July 2013, AVS supported 114 tours spanning 9 different countries, including tours in 23 U.S. states. Tours over the past three and a half years have connected Arctic experts with over 6,600 audience members. Post-tour evaluations show that AVS consistently rates high for broadening interest and understanding of arctic issues. AVS provides a case study for how face-to-face interactions between arctic scientists and general audiences can produce high-impact results. Further information can be found at: http://www.arcus.org/arctic-visiting-speakers.

  19. A Hero in the Friendly Arctic: Deconstructing Vilhjalmur Stefansson's Rhetorical Maneuver

    Directory of Open Access Journals (Sweden)

    Silje Gaupseth

    2012-05-01

    Full Text Available The article deals with Arctic explorer and anthropologist Vilhjalmur Stefansson's self-presentation in the expedition account The Friendly Arctic: The Story of Five Years in Polar Regions (1921, which tells the story of his travels and trials in the Canadian High Arctic in the years between 1913-1918. The account has been considered a key text to Stefansson's Arctic career, and provides a textbook example of his characteristic theory of living off the country in the so-called Eskimo way. Against the background of Stefansson's debated position as Arctic expert and visionary, I ask if it is possible to read the kind of criticism with which Stefansson frequently was met as rooted in some of the narrative aspects of his account. The narrative persona or implied author is a central element in the literature of exploration, as several literary scholars have pointed out. My reading is centred around the implied author of The Friendly Arctic, which I argue must be read in light of the sometimes conflicting roles given to Stefansson as protagonist and narrator in his own story. Close-readings of passages from the account raise the dilemma of how it is possible to present oneself as a hero in an essentially friendly Arctic.

  20. Laurentian origin for the North Slope of Alaska: Implications for the tectonic evolution of the Arctic

    Science.gov (United States)

    Strauss, J. V.; Macdonald, F. A.; Taylor, J. F.; Repetski, John E.; McClelland, W. C.

    2013-01-01

    The composite Arctic Alaska–Chukotka terrane plays a central role in tectonic reconstructions of the Arctic. An exotic, non-Laurentian origin of Arctic Alaska–Chukotka has been proposed based on paleobiogeographic faunal affinities and various geochronological constraints from the southwestern portions of the terrane. Here, we report early Paleozoic trilobite and conodont taxa that support a Laurentian origin for the North Slope subterrane of Arctic Alaska, as well as new Neoproterozoic–Cambrian detrital zircon geochronological data, which are both consistent with a Laurentian origin and profoundly different from those derived from similar-aged strata in the southwestern subterranes of Arctic Alaska–Chukotka. The North Slope subterrane is accordingly interpreted as allochthonous with respect to northwestern Laurentia, but it most likely originated farther east along the Canadian Arctic or Atlantic margins. These data demonstrate that construction of the composite Arctic Alaska–Chukotka terrane resulted from juxtaposition of the exotic southwestern fragments of the terrane against the northern margin of Laurentia during protracted Devonian(?)–Carboniferous tectonism.

  1. Canadian identity: Implications for international social work by Canadians

    DEFF Research Database (Denmark)

    Hiranandani, Vanmala Sunder

    2011-01-01

    This paper is in response to recent calls to conceptualize and articulate Canadian perspectives and experiences in international social work, given that the Canadian standpoint has been lacking in international social work literature. This paper contends that it is imperative, first of all, to cr...

  2. Lidar Measurements of Tropospheric Ozone in the Arctic

    Directory of Open Access Journals (Sweden)

    Seabrook Jeffrey

    2016-01-01

    Full Text Available This paper reports on differential absorption lidar (DIAL measurements of tropospheric ozone in the Canadian Arctic during springtime. Measurements at Eureka Weather Station revealed that mountains have a significant effect on the vertical structure of ozone above Ellesmere Island. Ozone depletion events were observed when air that had spent significant time near to the frozen surface of the Arctic Ocean reached Eureka. This air arrived at Eureka by flowing over the surrounding mountains. Surface level ozone depletions were not observed during periods when the flow of air from over the sea ice was blocked by mountains. In the case of blocking there was an enhancement in the amount of ozone near the surface as air from the mid troposphere descended in the lee of the mountains. Three case studies will be shown in the presentation, while one is described in this paper.

  3. Lidar Measurements of Tropospheric Ozone in the Arctic

    Science.gov (United States)

    Seabrook, Jeffrey; Whiteway, James

    2016-06-01

    This paper reports on differential absorption lidar (DIAL) measurements of tropospheric ozone in the Canadian Arctic during springtime. Measurements at Eureka Weather Station revealed that mountains have a significant effect on the vertical structure of ozone above Ellesmere Island. Ozone depletion events were observed when air that had spent significant time near to the frozen surface of the Arctic Ocean reached Eureka. This air arrived at Eureka by flowing over the surrounding mountains. Surface level ozone depletions were not observed during periods when the flow of air from over the sea ice was blocked by mountains. In the case of blocking there was an enhancement in the amount of ozone near the surface as air from the mid troposphere descended in the lee of the mountains. Three case studies will be shown in the presentation, while one is described in this paper.

  4. On the issue of the Precambrian basement of the Arctic shelf

    Science.gov (United States)

    Vernikovsky, Valery A.; Korago, Evgeny A.; Proskurnin, Vasily F.; Sobolev, Nikolay N.

    2015-04-01

    Many researchers of the geological structures of the Russian Arctic concluded that the basements of the terranes composing the Arctic shelf and continental slopes have a Precambrian age. It is assumed that these terranes are actually fragments of the ancient Arctida paleocontinent [Zonenshain, Natapov, 1987] that broke up as a result of rifting and its separate plates and terranes either were overlain by continental margins sediments or included in the fold belts in the periphery of the ocean. In the western part of the Russian Arctic, a Grenvillian and Mesoproterozoic basement was demonstrated for Svalbard, Novaya Zemlya and Taimyr Peninsula, and at least a Neoproterozoic basement was established for structures in the basement of Severnaya Zemlya archipelago. In the eastern part of the Russian Arctic, such proofs were almost nonexistent. In recent years, new information was obtained concerning the continental nature and Precambrian age of the basement crust of the New Siberian Islands and De Long archipelagos as well as probably the Mendeleev Ridge. For the New Siberian Islands and De Long archipelagos, a whole series of geochronological evidence was obtained in addition to geological data (horizontally bedding Early Paleozoic passive continental margin sediments (Cambrian, Ordovician) at Bennett Island). In magmatic and tuffaceous-sedimentary rocks of Henrietta and Zhokhov islands we discovered zircons that had formed from magmatic crystallization in the Late Neoproterozoic. New U-Pb data for zircons from rocks of these islands do not contradict isotopic dating obtained earlier by other methods - Ar/Ar and Sm/Nd in different laboratories. Considering different closure temperatures for isotopic systems, these new results complement each other. On the islands of the eastern sector of the Russian Arctic, a Neoproterozoic complex of rocks is most certainly established in the basement of the mesozoides of Vrangel Island. Here were discovered metamorphosed volcanics

  5. Arctic Rabies – A Review

    Directory of Open Access Journals (Sweden)

    Prestrud Pål

    2004-03-01

    Full Text Available Rabies seems to persist throughout most arctic regions, and the northern parts of Norway, Sweden and Finland, is the only part of the Arctic where rabies has not been diagnosed in recent time. The arctic fox is the main host, and the same arctic virus variant seems to infect the arctic fox throughout the range of this species. The epidemiology of rabies seems to have certain common characteristics in arctic regions, but main questions such as the maintenance and spread of the disease remains largely unknown. The virus has spread and initiated new epidemics also in other species such as the red fox and the racoon dog. Large land areas and cold climate complicate the control of the disease, but experimental oral vaccination of arctic foxes has been successful. This article summarises the current knowledge and the typical characteristics of arctic rabies including its distribution and epidemiology.

  6. Arctic indigenous women consume greater than acceptable levels of organochlorines.

    Science.gov (United States)

    Kuhnlein, H V; Receveur, O; Muir, D C; Chan, H M; Soueida, R

    1995-10-01

    Exposure to polychlorinated biphenyls and organochlorine pesticides through traditional food resources was examined for Arctic Indigenous women living in two cultural and environmental areas of the Canadian Arctic--one community representing Baffin Island Inuit in eastern Arctic and two communities representing Sahtú Dene/Métis in western Arctic. Polychlorinated biphenyls, toxaphene, chlorobenzenes, hexachlorocyclohexanes, dichlorodiphenyltrichloroethane, chlordane-related compounds and dieldrin were determined in local food resources as normally prepared and eaten. Quantified dietary recalls taken seasonally reflected normal consumption patterns of these food resources by women in three age groups: 20-40 y, 41-60 y and > or = 61 y. There was wide variation of intake of all organochlorine contaminants in both areas and among age groups for the Sahtú. Fifty percent of the intake recalls collected from the Baffin Inuit exceeded the acceptable daily intake for chlordane-related compounds and toxaphene, and a substantial percentage of the intake records for dieldrin and polychlorinated biphenyls exceeded the acceptable or tolerable daily intake levels. Primary contributing foods to organochlorine contaminants intake for the Baffin Inuit were meat and blubber of ringed seal, blubber of walrus and mattak and blubber of narwal. Important foods contributing organochlorine contaminant to the Sahtú Dene/Métis were caribou, whitefish, inconnu, trout and duck. The superior nutritional benefits and potential health risks of traditional food items are reviewed, as are implications for monitoring organochlorine contaminant contents of food, clinical symptoms and food use. PMID:7562084

  7. Impacts of Declining Arctic Sea Ice: An International Challenge

    Science.gov (United States)

    Serreze, M.

    2008-12-01

    As reported by the National Snow and Ice Data Center in late August of 2008, Arctic sea ice extent had already fallen to its second lowest level since regular monitoring began by satellite. As of this writing, we were closing in on the record minimum set in September of 2007. Summers may be free of sea ice by the year 2030. Recognition is growing that ice loss will have environmental impacts that may extend well beyond the Arctic. The Arctic Ocean will in turn become more accessible, not just to tourism and commercial shipping, but to exploitation of oil wealth at the bottom of the ocean. In recognition of growing accessibility and oil operations, the United States Coast Guard set up temporary bases this summer at Barrow and Prudhoe Bay, AK, from which they conducted operations to test their readiness and capabilities, such as for search and rescue. The Canadians have been busy showing a strong Arctic presence. In August, a German crew traversed the Northwest Passage from east to west in one of their icebreakers, the Polarstern. What are the major national and international research efforts focusing on the multifaceted problem of declining sea ice? What are the areas of intersection, and what is the state of collaboration? How could national and international collaboration be improved? This talk will review some of these issues.

  8. CBSIT 2009: Airborne Validation of Envisat Radar Altimetry and In Situ Ice Camp Measurements Over Arctic Sea Ice

    Science.gov (United States)

    Connor, Laurence; Farrell, Sinead; McAdoo, David; Krabill, William; Laxon, Seymour; Richter-Menge, Jacqueline; Markus, Thorsten

    2010-01-01

    The past few years have seen the emergence of satellite altimetry as valuable tool for taking quantitative sea ice monitoring beyond the traditional surface extent measurements and into estimates of sea ice thickness and volume, parameters that arc fundamental to improved understanding of polar dynamics and climate modeling. Several studies have now demonstrated the use of both microwave (ERS, Envisat/RA-2) and laser (ICESat/GLAS) satellite altimeters for determining sea ice thickness. The complexity of polar environments, however, continues to make sea ice thickness determination a complicated remote sensing task and validation studies remain essential for successful monitoring of sea ice hy satellites. One such validation effort, the Arctic Aircraft Altimeter (AAA) campaign of2006. included underflights of Envisat and ICESat north of the Canadian Archipelago using NASA's P-3 aircraft. This campaign compared Envisat and ICESat sea ice elevation measurements with high-resolution airborne elevation measurements, revealing the impact of refrozen leads on radar altimetry and ice drift on laser altimetry. Continuing this research and validation effort, the Canada Basin Sea Ice Thickness (CBSIT) experiment was completed in April 2009. CBSIT was conducted by NOAA. and NASA as part of NASA's Operation Ice Bridge, a gap-filling mission intended to supplement sea and land ice monitoring until the launch of NASA's ICESat-2 mission. CBIST was flown on the NASA P-3, which was equipped with a scanning laser altimeter, a Ku-band snow radar, and un updated nadir looking photo-imaging system. The CB5IT campaign consisted of two flights: an under flight of Envisat along a 1000 km track similar to that flown in 2006, and a flight through the Nares Strait up to the Lincoln Sea that included an overflight of the Danish GreenArc Ice Camp off the coast of northern Greenland. We present an examination of data collected during this campaign, comparing airborne laser altimeter measurements

  9. Canadian photovoltaic industry directory

    International Nuclear Information System (INIS)

    This directory has been prepared to help potential photovoltaic (PV) customers identify Canadian-based companies who can meet their needs, and to help product manufacturers and distributors identify potential new clients and/or partners within the PV industry for new and improved technologies. To assist the reader, an information matrix is provided that identifies the product and service types offered by each firm and its primary clients served. A list of companies by province or territory is also included. The main section lists companies in alphabetical order. Information presented for each includes address, contact person, prime activity, geographic area served, languages in which services are offered, and a brief company profile

  10. The Canadian safeguards program

    International Nuclear Information System (INIS)

    In support of the Treaty on the Non-Proliferation of Nuclear Weapons Canada provides technical support to the International Atomic Energy Agency for the development of safeguards relevant to Canadian designed and built nuclear facilities. Some details of this program are discussed, including the philosophy and development of CANDU safeguards systems; the unique equipment developed for these systems; the provision of technical experts; training programs; liaison with other technical organizations; research and development; implementation of safeguards systems at various nuclear facilities; and the anticipated future direction of the safeguards program

  11. Microarray and Real-Time PCR Analyses of the Responses of High-Arctic Soil Bacteria to Hydrocarbon Pollution and Bioremediation Treatments▿

    OpenAIRE

    Yergeau, Etienne; Arbour, Mélanie; Brousseau, Roland; Juck, David; Lawrence, John R.; Masson, Luke; Whyte, Lyle G; Greer, Charles W.

    2009-01-01

    High-Arctic soils have low nutrient availability, low moisture content, and very low temperatures and, as such, they pose a particular problem in terms of hydrocarbon bioremediation. An in-depth knowledge of the microbiology involved in this process is likely to be crucial to understand and optimize the factors most influencing bioremediation. Here, we compared two distinct large-scale field bioremediation experiments, located at the Canadian high-Arctic stations of Alert (ex situ approach) a...

  12. On Realities of Canadian Multiculturalism

    Institute of Scientific and Technical Information of China (English)

    李梦辰

    2013-01-01

    Canada is a multicultural country which was mainly established by immigrants. Just because of that, Canadian govern⁃ment has carried out the policy of multiculturalism since1970s. However, it has encountered many problems such as policy con⁃flicts, national identity, democracy-inquiry and racial discrimination, etc. Hence the Canadian multiculturalism has been in a di⁃lemma.

  13. Arctic Solutions The Frozen (Thawing) Relations of the High North

    International Nuclear Information System (INIS)

    It's cold, inhospitable and deadly. The image of the Arctic in years past is one of bewilderment, ignorance and awe. How the image of the Arctic has changed in recent years can be directly linked to our recognition that the Arctic has a great deal to offer in meeting the basic needs of future generations. Although we are still in awe of the Arctic's cruel beauty, new technologies are making it easier to explore the once unmanageable environment. The Arctic has moved into the mainstream with a host of suitors jockeying for position in the race to possess the Arctic and all that it contains. To highlight this increased interest, Russia's 'National Security Until 2020' initiative, has upgraded the High North to one of Russia's main priorities and identifies the Arctic as liable to produce military conflict in the future linked to competition for the Arctic's abundant raw materials.1 Even Canada, a peaceful and respectful country, has stepped outside the box of traditional Canadian rhetoric by giving Canada's Northern Strategy a tag line: 'Our North, our heritage, our future'. The Arctic is increasingly viewed as central to meeting the challenges of an ever changing world where climate change and economic benefit drive international agreements and policies. However Canada and Russia are not the only actors here. The other Arctic Five states: Denmark, Norway, and the United States of America all lay claims to some area or activity within the Arctic region. The Arctic is a unique part of this world, one that has been left largely untouched by human hands, and one that is on the brink of being changed forever. To fully understand Arctic issues, resource figures must be taken into account. Every nation involved in the Arctic debate has considered and based its policies on its set of numbers and resource estimates. A U.S. Geological Survey (USGS) in 2009 put Arctic resource figures in the range of thirty percent of the remaining world reserves of natural gas and ten percent

  14. Mapping Snowfields in the High Arctic by UAV

    Science.gov (United States)

    Klump, Jens; Leya, Thomas; Fuhr, Günter

    2014-05-01

    Plant habitats are often influenced by small scale factors of substrate composition, topography and water sources that influence the availability of water and nutrients. In our lomg-term study to investigate the the distribution and dispersal strategies as well as the life cycle of psychrophilic algae (snow algae) it was necessary to get a better understanding of the structure of the snowfields where these algae live. Previous attempts to map snowfields using tethered platforms, such as kites or balloons, had proven to be difficult due to the very unstable weather conditions in the extreme environment of the High Arctic. The inherent problems of tethered platforms could be overcome with unmanned aerial vehicles (UAV). During the August 2013 field campaign on the Svalbard archipelago we used an Asctec Falcon 8 UAV to map snowfields and glacier surfaces in the visible and thermal infra-red spectrum. The georeferenced images were assembled into photo mosaic maps which were also converted into digital elevation models. The photo mosaic maps and digital elevation models gave new insights into small-scale factors that influence the physical and chemical conditions of the snow algae habitat. This presentation gives an overview of our results from the use of UAV for the mapping of snowfields in the High Arctic and discusses the risks and limitations of UAV in this extreme environment.

  15. Seismological observations of glaciers dynamic on the Spitsbergen archipelago

    Directory of Open Access Journals (Sweden)

    Fedorov A. V.

    2016-03-01

    Full Text Available The paper provides a brief description of results of Spitsbergen glacier observations by the seismic method. The study has been carried out both by permanent and temporary stations data. Characteristic features of glacier-related seismic events have been shown. Main areas of glacier seismic activity on the Archipelago have been revealed. A detailed study of Horsund-fjord glacier activity has been carried out using local seismic station HSPB data. Temporal and spatial distributions of glacier-related events have been obtained for the area. Season variations in temporal distribution of the events have been found

  16. Early Bomb Radiocarbon Detected in Palau Archipelago Corals

    OpenAIRE

    Glynn, Danielle; Druffel, Ellen; Griffin, Sheila; Dunbar, R. B.; Osbourne, M.; Sanchez-Cabeza, J.-A.

    2013-01-01

    In order to evaluate the variability in surface water masses in the western Pacific warm pool, we report high-precision radiocarbon measurements in annual and seasonal bands from Porites lutea corals collected from the Palau Archipelago (7°N, 134°E). Annual coral bands from 1945 to 2008 and seasonal samples from 1953 to 1957 were analyzed to capture the initial early input of bomb 14C from surface thermonuclear weapons testing in the Marshall Islands. Results show a pre-bomb average Δ14C valu...

  17. Backcountry Travel Emergencies in Arctic Canada: A Pilot Study in Public Health Surveillance

    Directory of Open Access Journals (Sweden)

    Stephanie K. Young

    2016-03-01

    Full Text Available Residents in the Canadian Arctic regularly travel in remote, backcountry areas. This can pose risks for injuries and death, and create challenges for emergency responders and health systems. We aimed to describe the extent and characteristics of media-reported backcountry travel emergencies in two Northern Canadian territories (Nunavut and Northwest Territories. A case-series of all known incidents between 2004 and 2013 was established by identifying events in an online search of two media outlets, Nunatsiaq News and Northern News Services. We identified 121 incidents; these most commonly involved young men, and death occurred in just over 25% of cases. The territories differed in the seasonal patterns. News media provides a partial source of data to estimate the extent and characteristics of backcountry emergencies. This information is needed to improve emergency preparedness and health system responsiveness in the Arctic.

  18. Backcountry Travel Emergencies in Arctic Canada: A Pilot Study in Public Health Surveillance.

    Science.gov (United States)

    Young, Stephanie K; Tabish, Taha B; Pollock, Nathaniel J; Young, T Kue

    2016-03-01

    Residents in the Canadian Arctic regularly travel in remote, backcountry areas. This can pose risks for injuries and death, and create challenges for emergency responders and health systems. We aimed to describe the extent and characteristics of media-reported backcountry travel emergencies in two Northern Canadian territories (Nunavut and Northwest Territories). A case-series of all known incidents between 2004 and 2013 was established by identifying events in an online search of two media outlets, Nunatsiaq News and Northern News Services. We identified 121 incidents; these most commonly involved young men, and death occurred in just over 25% of cases. The territories differed in the seasonal patterns. News media provides a partial source of data to estimate the extent and characteristics of backcountry emergencies. This information is needed to improve emergency preparedness and health system responsiveness in the Arctic. PMID:26950137

  19. Comparative Views of Arctic Sea Ice Growth

    Science.gov (United States)

    2000-01-01

    grows and contorts over time. 'Using this new data set, we have the first estimates of how much ice has been produced and where it formed during the winter. We have never been able to do this before,' said Kwok. 'Through our radar maps of the Arctic Ocean, we can actually see ice breaking apart and thin ice growth in the new openings.'RADARSAT gives researchers a piece of the overall puzzle every three days by creating a complete image of the Arctic. NASA scientists then put those puzzle pieces together to create a time-lapsed view of this remote and inhospitable region. So far, they have processed one season's worth of images.'We can see large cracks in the ice cover, where most ice grows,' said Kwok. 'These cracks are much longer than previously thought, some as long as 2,000 kilometers (1,200 miles),' Kwok continued. 'If the ice is thinning due to warming, we'll expect to see more of these long cracks over the Arctic Ocean.'Scientists believe this is one of the most significant breakthroughs in the last two decades of ice research. 'We are now in a position to better understand the sea ice cover and the role of the Arctic Ocean in global climate change,' said Kwok.Radar can see through clouds and any kind of weather system, day or night, and as the Arctic regions are usually cloud-covered and subject to long, dark winters, radar is proving to be extremely useful. However, compiling these data into extremely detailed pictures of the Arctic is a challenging task.'This is truly a major innovation in terms of the quantities of data being processed and the novelty of the methods being used,' said Verne Kaupp, director of the Alaska SAR Facility at the University of Alaska, Fairbanks.The mission is a joint project between JPL, the Alaska SAR Facility, and the Canadian Space Agency. Launched by NASA in 1995, the Radarsat satellite is operated by the Canadian Space Agency. JPL manages the Sea Ice Thickness Derived From High Resolution Radar Imagery project for NASA's Earth

  20. Canadian beef quality audit.

    Science.gov (United States)

    Van Donkersgoed, J; Jewison, G; Mann, M; Cherry, B; Altwasser, B; Lower, R; Wiggins, K; Dejonge, R; Thorlakson, B; Moss, E; Mills, C; Grogan, H

    1997-01-01

    A study was conducted in 4 Canadian processing plants in 1995-96 to determine the prevalence of quality defects in Canadian cattle. One percent of the annual number of cattle processed in Canada were evaluated on the processing floor and 0.1% were graded in the cooler. Brands were observed on 37% and multiple brands on 6% of the cattle. Forty percent of the cattle had horns, 20% of which were scurs, 33% were stubs, 10% were tipped, and 37% were full length. Tag (mud and manure on the hide) was observed on 34% of the cattle. Bruises were found on 78% of the carcasses, 81% of which were minor in severity. Fifteen percent of the bruises were located on the round, 29% on the loin, 40% on the rib, 16% on the chuck, and 0.02% on the brisket. Grubs were observed in 0.02% of the steers, and injection sites were observed in 1.3% of whole hanging carcasses. Seventy percent of the livers were passed for human food and 14% for pet food; 16% were condemned. Approximately 71% of the liver condemnations were due to liver abscesses. Four percent of the heads, 6% of the tongues, and 0.2% of whole carcasses were condemned. The pregnancy rate in female cattle was approximately 6.7%. The average hot carcass weight was 357 kg (s = 40) in steers, 325 kg (s = 41) in heifers, 305 kg (s = 53) in cows, 388 kg (s = 62) in virgin bulls and 340 kg (s = 39) in mature bulls. The average ribeye area in all cattle was 84 cm2 (s = 12); range 29 cm2 to 128 cm2. Grade fat was highly variable and averaged 9 mm (s = 4) for steers and heifers, 6 mm (s = 6) for cows, 5 mm (s = 1) for virgin bulls, and 4 mm (s = 0.5) for mature bulls. The average lean meat yield was 59.7% in cattle (s = 3.4); range 39% to 67%. One percent of the carcasses were devoid of marbling, 1% were dark cutters, and 0.05% of the steer carcasses were staggy. Six percent of the carcasses had poor conformation, 3.7% were underfinished, and 0.7% were overfinished. Yellow fat was observed in 4% of the carcasses; 10% of carcasses were

  1. Helicobacter pylori infection in Canada’s arctic: Searching for the solutions

    OpenAIRE

    Cheung, Justin; Goodman, Karen; Munday, Rachel; Heavner, Karen; Huntington, Janis; Morse, John; van Zanten, Sander Veldhuyzen; Fedorak, Richard N.; Corriveau, Andre; Bailey, Robert J.

    2008-01-01

    The Canadian North Helicobacter pylori (CANHelp) working group is a team composed of investigators, health officials and community leaders from Alberta and the Northwest Territories. The group’s initial goals are to investigate the impact of H pylori infection on Canada’s Arctic communities; subsequent goals include identifying treatment strategies that are effective in this region and developing recommendations for health policy aimed at management of H pylori infection. The team’s investiga...

  2. Canadian cogeneration economics

    International Nuclear Information System (INIS)

    An aggressive cogeneration industry has developed in Canada, and is becoming a tool for provincial utilities to manage the procurement of independently generated power, while restricting plant size, maximizing socioeconomic benefit, minimizing environmental impacts and managing their own risks. An overview is presented of the economics of cogeneration in Canada. The Canadian cogeneration industry is driven by 3 key economic factors: utility power sale contracts, fuel pricing, and tax benefits. Utility cogeneration purchases, tax benefits, fuel prices, cogeneration efficiency, fuels, fuel strategies, displacement projects, solid fuel vs natural gas, operating flexibility, gas turbines, heat recovery steam generators, industrial and aeroderivative units, combined cycle steam turbines, steam injection, supplementary or duct firing, financial aspects and project management are discussed. 15 figs., 7 tabs

  3. Communicating Arctic Change (Invited)

    Science.gov (United States)

    Serreze, M.

    2009-12-01

    Nowhere on the planet are emerging signals of climate change more visible than in the Arctic. Rapid warming, a quickly shrinking summer sea ice cover, and thawing permafrost, will have impacts that extend beyond the Arctic and may reverberate around the globe. The National Snow and Ice Data Center (NSIDC) of the University of Colorado has taken a leading role in trying to effectively communicate the science and importance of Arctic change. Our popular “Sea Ice News and Analysis” web site tracks the Arctic’s shrinking ice cover and provides scientific analysis with language that is accurate yet accessible to a wide audience. Our Education Center provides accessible information on all components of the Earth’s cryosphere, the changes being seen, and how scientists conduct research. A challenge faced by NSIDC is countering the increasing level of confusion and misinformation regarding Arctic and global change, a complex problem that reflects the low level of scientific literacy by much of the public, the difficulties many scientists face in communicating their findings in accurate but understandable terms, and efforts by some groups to deliberately misrepresent and distort climate change science. This talk will outline through examples ways in which NSIDC has been successful in science communication and education, as well as lessons learned from failures.

  4. Contest for Arctic

    International Nuclear Information System (INIS)

    Warming of Earth surface access the defrosting north extensiveness of economic activities. The Russian Federation (RF) has delegated two bathyscaphs in order to put capsule with Russian flag on the bottom under North Pole. In this paper the territorial pretensions of the RF on the Arctic region are discussed

  5. Temporal analysis of remotely sensed turbidity in a coastal archipelago

    Science.gov (United States)

    Suominen, Tapio; Tolvanen, Harri

    2016-07-01

    A topographically fragmental archipelago with dynamic waters set the preconditions for assessing coherent remotely sensed information. We generated a turbidity dataset for an archipelago coast in the Baltic Sea from MERIS data (FSG L1b), using CoastColour L1P, L2R and L2W processors. We excluded land and mixed pixels by masking the imagery with accurate (1:10 000) shoreline data. Using temporal linear averaging (TLA), we produced satellite-imagery datasets applicable to temporal composites for the summer seasons of three years. The turbidity assessments and temporally averaged data were compared to in situ observations obtained with coastal monitoring programs. The ability of TLA to estimate missing pixel values was further assessed by cross-validation with the leave-one-out method. The correspondence between L2W turbidity and in situ observations was good (r = 0.89), and even after applying TLA the correspondence remained acceptable (r = 0.78). The datasets revealed spatially divergent temporal water characteristics, which may be relevant to the management, design of monitoring and habitat models. Monitoring observations may be spatially biased if the temporal succession of water properties is not taken into account in coastal areas with anisotropic dispersion of waters and asynchronous annual cycles. Accordingly, areas of varying turbidity may offer a different habitat for aquatic biota than areas of static turbidity, even though they may appear similar if water properties are measured for short annual periods.

  6. The Idea of the Archipelago: Contemplating Island Relations

    Directory of Open Access Journals (Sweden)

    Elaine Stratford

    2013-05-01

    Full Text Available Creative, innovative, and timely research on islands and island futures is warranted and pressing, not least because island(ers are poorly served by established tropes of them as subordinate to continents or mainlands. Opportunities exist to provide a more thoroughgoing account of island life and island relations, and the seven papers in this special issue address that task. In works that consider islands in the Timor Sea, the Caribbean, the Pacific, Atlantic and Southern Oceans, and that span several different disciplinary frames—archival-historical, critical theoretical, literary, cultural, geopolitical, sociological and artistic—these papers evidence both the diversity of approach to thinking with the archipelago, and numerous points in common. Among the latter is an understanding that island relations are built on connection, assemblage, mobility, and multiplicity, and a commitment to critically examine the ways in which these entanglements affect and give effect to island life. The models of island relationality brought to light by this collective focus on the archipelago reveal new and diverse connections of island peoples with their physical and cultural environments, and with the world beyond; create spaces for growing resilience, association and engagement; and invite further study.

  7. The Arctic Circle

    Science.gov (United States)

    McDonald, Siobhan

    2016-04-01

    My name is Siobhan McDonald. I am a visual artist living and working in Dublin. My studio is based in The School of Science at University College Dublin where I was Artist in Residence 2013-2015. A fascination with time and the changeable nature of landmass has led to ongoing conversations with scientists and research institutions across the interweaving disciplines of botany, biology and geology. I am developing a body of work following a recent research trip to the North Pole where I studied the disappearing landscape of the Arctic. Prompted by my experience of the Arctic shelf receding, this new work addresses issues of the instability of the earth's materiality. The work is grounded in an investigation of material processes, exploring the dynamic forces that transform matter and energy. This project combines art and science in a fascinating exploration of one of the Earth's last relatively untouched wilderness areas - the High Arctic to bring audiences on journeys to both real and artistically re-imagined Arctic spaces. CRYSTALLINE'S pivotal process is collaboration: with The European Space Agency; curator Helen Carey; palaeontologist Prof. Jenny McElwain, UCD; and with composer Irene Buckley. CRYSTALLINE explores our desire to make corporeal contact with geological phenomena in Polar Regions. From January 2016, in my collaboration with Jenny McElwain, I will focus on the study of plants and atmospheres from the Arctic regions as far back as 400 million years ago, to explore the essential 'nature' that, invisible to the eye, acts as imaginary portholes into other times. This work will be informed by my arctic tracings of sounds and images recorded in the glaciers of this disappearing frozen landscape. In doing so, the urgencies around the tipping of natural balances in this fragile region will be revealed. The final work will emerge from my forthcoming residency at the ESA in spring 2016. Here I will conduct a series of workshops in ESA Madrid to work with

  8. Marine actinomycetes from Madeira Archipelago preliminary taxonomic studies

    Directory of Open Access Journals (Sweden)

    Ilda Santos Sanches

    2014-06-01

    Full Text Available The oceans cover 70 % of the Earth´s surface and harbor most of the planet´s biodiversity. However the microbiological component of this diversity remains relatively unexplored. Marine actinomycetes, are a robust resource of chemically prolific novelty. Producing structurally unique biological active secondary metabolites, generating a valuable source for innovative biotechnology and drug discovery[1,2]. As a consequence, the ecological role of actinomycetes and their marine ecosystems may no longer be neglected. It is crucial to move our research efforts into ocean regions for which we know little or nothing about the indigenous microbial diversity. The Portuguese Archipelago, Madeira is located in the Macaronesian Atlantic region, emerging from the African tectonic plate, found in the extreme south of the Tore-Madeira ridge, has a unique biogeography and biodiversity. These distinctive characteristics combined with the fact that Madeira have never been explored, as far as indigenous marine actinomycetes are concerned, makes it from the scientific point of view, the perfect target for our studies. From 662 marine sediment samples collected along Madeira Archipelago (Figure 1 during June of 2012, covering depths from 10-1310 m, a total of 421 actinomycete strains were isolated. In a previous study, an assemblage of 82 strains was selected for taxonomic identification, having into account representative morphological diversity characteristics of the actinomycetes, isolated from Madeira Archipelago. Based on 16S rRNA gene sequencing, it was observed that the genera Streptomyces, Micromonospora and Salinispora were predominant, 81% [3]. Additionally, in a recent study, our team selected 168 strains with Salinispora look-alike morphological features. From these 28 strains were identified as belonging to the seawater-obligate marine actinomycete genus Salinispora. Representing the first report of Salinispora spp. in the Macaronesian Atlantic Ocean

  9. Chemical changes in the Arctic troposphere at polar sunrise

    International Nuclear Information System (INIS)

    At polar sunrise, the Arctic troposphere (0 to ∼8 km) is a unique chemical reactor influenced by human activity and the Arctic Ocean. It is surrounded by industrialized continents that in winter contribute gaseous and particulate pollution (Arctic haze). It is underlain by the flat Arctic Ocean from which it is separated by a crack-ridden ice membrane 3 to 4 m thick. Ocean to atmosphere exchange of heat, water vapor and marine biogenic gases influence the composition of the reactor. From 21 September to 21 December to 21 March, the region north of the Arctic circle goes from a completely sunlit situation to a completely dark one and then back to light. At the same time the lower troposphere is stably stratified. This hinders vertical mixing. In this environment, chemical reactions involving sunlight are much slower than further south. Thus, it would not be surprising to find a high abundance of photochemically reactive compounds in the atmosphere at polar sunrise. Between complete dark in February and complete light in April, a number of chemical changes in the lower troposphere are observed. Perhaps the most sensational is the destruction of lower tropospheric ozone accompanied by production of filterable bromine and iodine. The latter are likely of marine origin, although their production may involve anthropogenic compounds. Another change is the shift in the fraction of total sulfur in its end oxidation state (VI) from 50% to 90%. Several gaseous hydrocarbons disappear from the atmosphere at this time. Preliminary observations also indicate a maximum in total non-black carbon on particulate matter. This is consistent with the formation of non-volatile organics from photochemically induced reactions of gas phase organics. Results of the Canadian Polar Sunrise Experiment 1988 are presented

  10. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic.

    Science.gov (United States)

    Peacock, Elizabeth; Sonsthagen, Sarah A; Obbard, Martyn E; Boltunov, Andrei; Regehr, Eric V; Ovsyanikov, Nikita; Aars, Jon; Atkinson, Stephen N; Sage, George K; Hope, Andrew G; Zeyl, Eve; Bachmann, Lutz; Ehrich, Dorothee; Scribner, Kim T; Amstrup, Steven C; Belikov, Stanislav; Born, Erik W; Derocher, Andrew E; Stirling, Ian; Taylor, Mitchell K; Wiig, Øystein; Paetkau, David; Talbot, Sandra L

    2015-01-01

    We provide an expansive analysis of polar bear (Ursus maritimus) circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how genetic demography changed with ancient fluctuations in climate. Characterizing their circumpolar genetic structure using microsatellite data, we defined four clusters that largely correspond to current ecological and oceanographic factors: Eastern Polar Basin, Western Polar Basin, Canadian Archipelago and Southern Canada. We document evidence for recent (ca. last 1-3 generations) directional gene flow from Southern Canada and the Eastern Polar Basin towards the Canadian Archipelago, an area hypothesized to be a future refugium for polar bears as climate-induced habitat decline continues. Our data provide empirical evidence in support of this hypothesis. The direction of current gene flow differs from earlier patterns of gene flow in the Holocene. From analyses of mitochondrial DNA, the Canadian Archipelago cluster and the Barents Sea subpopulation within the Eastern Polar Basin cluster did not show signals of population expansion, suggesting these areas may have served also as past interglacial refugia. Mismatch analyses of mitochondrial DNA data from polar and the paraphyletic brown bear (U. arctos) uncovered offset signals in timing of population expansion between the two species, that are attributed to differential demographic responses to past climate cycling. Mitogenomic structure of polar bears was shallow and developed recently, in contrast to the multiple clades of brown bears. We found no genetic signatures of recent hybridization between the species in our large, circumpolar sample, suggesting that recently observed hybrids represent localized events. Documenting changes in subpopulation connectivity will allow

  11. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic.

    Directory of Open Access Journals (Sweden)

    Elizabeth Peacock

    Full Text Available We provide an expansive analysis of polar bear (Ursus maritimus circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how genetic demography changed with ancient fluctuations in climate. Characterizing their circumpolar genetic structure using microsatellite data, we defined four clusters that largely correspond to current ecological and oceanographic factors: Eastern Polar Basin, Western Polar Basin, Canadian Archipelago and Southern Canada. We document evidence for recent (ca. last 1-3 generations directional gene flow from Southern Canada and the Eastern Polar Basin towards the Canadian Archipelago, an area hypothesized to be a future refugium for polar bears as climate-induced habitat decline continues. Our data provide empirical evidence in support of this hypothesis. The direction of current gene flow differs from earlier patterns of gene flow in the Holocene. From analyses of mitochondrial DNA, the Canadian Archipelago cluster and the Barents Sea subpopulation within the Eastern Polar Basin cluster did not show signals of population expansion, suggesting these areas may have served also as past interglacial refugia. Mismatch analyses of mitochondrial DNA data from polar and the paraphyletic brown bear (U. arctos uncovered offset signals in timing of population expansion between the two species, that are attributed to differential demographic responses to past climate cycling. Mitogenomic structure of polar bears was shallow and developed recently, in contrast to the multiple clades of brown bears. We found no genetic signatures of recent hybridization between the species in our large, circumpolar sample, suggesting that recently observed hybrids represent localized events. Documenting changes in subpopulation

  12. Canadian National Vegetation Classification (CNVC)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The mandate of the CNVC is to comprehensively classify and describe natural and semi-natural Canadian vegetation in an ecologically meaningful manner. The...

  13. 1944. The Canadians in Normandy

    OpenAIRE

    W.A. Dorning

    2012-01-01

    The story of the Allied invasion of France in June 1944 has been told in countless military-history books. Previous publications on the Allied invasion and the subsequent Normandy campaign have, however, tended to concentrate on the British and American role in the fighting, while the Canadian contribution has received scant attention. This in itself is surprising, as the Canadians played a far from peripheral role in the invasion and the campaign which followed in the hinterland of Normandy....

  14. The delivery of organic contaminants to the Arctic food web: Why sea ice matters

    DEFF Research Database (Denmark)

    Pucko, M.; Stern, Gary; Macdonald, Robie;

    2015-01-01

    For decades sea ice has been perceived as a physical barrier for the loading of contaminants to the Arctic Ocean. We show that sea ice, in fact, facilitates the delivery of organic contaminants to the Arctic marine food web through processes that: 1) are independent of contaminant physical......–chemical properties (e.g. 2–3-fold increase in exposure to brine-associated biota), and 2) depend on physical–chemical properties and, therefore, differentiate between contaminants (e.g. atmospheric loading of contaminants to melt ponds over the summer, and their subsequent leakage to the ocean). We estimate...... the concentrations of legacy organochlorine pesticides (OCPs) and current-use pesticides (CUPs) in melt pond water in the Beaufort Sea, Canadian High Arctic, in 2008, at near-gas exchange equilibriumbased on Henry's lawconstants (HLCs), air concentrations and exchange dynamics. CUPs currently present the highest...

  15. Microbial Ecology at an Arctic Geothermal Spring

    Science.gov (United States)

    Starke, V.; Fogel, M. L.; Steele, A.; Arctic Mars Analog Svalbard Expedition (Amase)

    2011-12-01

    A critical question in microbial ecology concerns how variations in environmental conditions affect microbial community makeup. Arctic thermal springs provide an exceptional opportunity to study this question because they have very steep gradients in temperature, moisture, and mobility that place strong selective pressures on microorganisms. Troll Springs, located near 79°23'N, 13°26E in the Svalbard archipelago north of Norway, is one of the northernmost documented thermal springs on land. Precipitation of travertine (calcium carbonate) from Troll's carbonate-rich waters has built a complex terrace structure. Biological materials are present at all levels of the spring structure. To investigate this microbial community in detail, we analyzed DNA extracted from wet biofilms, granular samples and endoliths with 454 parallel-tagged pyrosequencing and automated ribosomal intergenic spacer analysis (ARISA). The aim is to provide a comprehensive overview of how the community at Troll Springs changes over the gradients in environmental conditions present. The 454 and ARISA data were analyzed using multivariate methods, including non-metric multidimensional scaling (nMDS). Results show a gradual transition in the makeup of the microbial community as the environment changes from aquatic to lithologic. These observations suggest a mechanism by which the rocks are colonized by microorganisms: biofilm becomes entrapped during carbonate precipitation. Use of a range of parameters and techniques in the data processing and multidimensional scaling provides additional insight into how community makeup varies across the environments present at the spring. Some more adaptable species are found across most environments, but change markedly in abundance as the conditions change. Other less adaptable species are found in fewer environments, being wholly absent in most. Continued analysis will help reveal which species are the most adaptable, and how their adaptive capabilities

  16. Crustal types of the Circumpolar Arctic

    Science.gov (United States)

    Kashubin, Sergey; Pavlenkova, Ninel; Petrov, Oleg; Milshtein, Evgenia; Shokalsky, Sergey; Erinchek, Yuri

    2016-04-01

    Deep seismic studies revealed unusual crustal structure in the Arctic Ocean. The thin (about 10 km) oceanic crust with seismic velocities Vp= 6.8-7.2 km/s is observed only in the narrow mid-oceanic ridge zone (the Gakkel ridge). The thick (25-35 km) continental crust covers the whole continental margins and the central part of the ocean. The continental type of the magnetic field with large local anomalies of different signs and irregular shapes is also observed in this area. However, the crust of the central Arctic (the Lomonosov, Mendeleev and Alpha ridges) differ from the crust of the Eurasia by the lower thickness of the upper granite-gneiss layer (velocities Vp=6.0-6.6 km/s): it is only 5-7 km in comparison with 15-20 km in the continent. The origin of such crust may be explained in two ways. Most frequently it is accounted for by the destruction and transformation of the continental crust by the basification that implies the enrichment of the crust by the rocks of basic composition from the mantle and the metamorphization of the continental rocks at the higher temperature and pressure. But in the central part of the Arctic Ocean the crust looks as an original one. The regular form of the large ridges and the continental type magnetic field were not destroyed by the basification processes which are usually irregular and most intensive in some local zones. The basification origin may be proposed for the Canadian and the South-Barents deep sedimentary basins with "suboceanic" crust (10-15 km of sediments and 10-15 km of the lower crust with Vp= 6.8-7.2 km/s). The other basins which stretch along fault zones outlined the central deep water part of the Arctic Ocean have the ''subcontinental' crust: the thickness of the granite-gneiss layer decreases in these basins and sometimes the high velocity intrusions are observed in the lower parts. The different crustal types are observed in the North Atlantic where the oceanic crust with linear magnetic anomalies is

  17. Acquatorialities of the Arctic Region

    DEFF Research Database (Denmark)

    Harste, Gorm

    2013-01-01

    In order to describe the Arctic system I propose using a concept functionally equivalent to territoriality, namely aquatoriality. Whether communicating about territoriality or aquatoriality, concepts and delimitations are both contingent to forms of communication systems. I will distinguish between...... six communications systems that differentiated from each other could become involved in the new deals emerging around the Arctic. Apart of an economic communication code about the Arctic, a legal code, ecological communication codes, and tourist communication codes, I will cope with the military...

  18. Canadian fuel development program

    International Nuclear Information System (INIS)

    CANDU power reactor fuel has demonstrated an enviable operational record. More than 99.9% of the bundles irradiated have provided defect-free service. Defect excursions are responsible for the majority of reported defects. In some cases research and development effort is necessary to resolve these problems. In addition, development initiatives are also directed at improvements of the current design or reduction of fueling cost. The majority of the funding for this effort has been provided by COG (CANDU Owners' Group) over the past 10 to 15 years. This paper contains an overview of some key fuel technology programs within COG. The CANDU reactor is unique among the world's power reactors in its flexibility and its ability to use a number of different fuel cycles. An active program of analysis and development, to demonstrate the viability of different fuel cycles in CANDU, has been funded by AECL in parallel with the work on the natural uranium cycle. Market forces and advances in technology have obliged us to reassess and refocus some parts of our effort in this area, and significant success has been achieved in integrating all the Canadian efforts in this area. This paper contains a brief summary of some key components of the advanced fuel cycle program. (Author) 4 figs., tab., 18 refs

  19. Canadian leadership in energy

    International Nuclear Information System (INIS)

    Canada's energy is complex and an important resource as it fuels and funds the economy. The unique character of Canada's energy production and consumption provides strength to the country. The purpose of this booklet was to highlight Canada's energy production and consumption and to demonstrate Canada's rank globally with other major global energy players. The document also presented information on the value of Canada's energy exports, Canada's relationship with the United States, and Canada's energy-related carbon dioxide emissions. Specifically, the document discussed Canada's energy in a global context; the value of Canada's energy exports; domestic value of energy; Canada's unique energy mix; Canada's electricity mix; Canada's carbon dioxide emissions; energy strategies; and the importance of energy to Canadians. It was concluded that there are 14 federal, provincial and territorial jurisdictions managing their respective energy resources. All of these regions, with the exception of Saskatchewan have produced an energy strategy document or a climate change action plan focusing on 8 areas of action, notably awareness; benefit; efficiency; development; diversification; electricity; and emissions. refs., tabs., figs.

  20. Factors Controlling Black Carbon Deposition in Snow in the Arctic

    Science.gov (United States)

    Qi, L.; Li, Q.; He, C.; Li, Y.

    2015-12-01

    This study evaluates the sensitivity of black carbon (BC) concentration in snow in the Arctic to BC emissions, dry deposition and wet scavenging efficiency using a 3D global chemical transport model GEOS-Chem driven by meteorological field GEOS-5. With all improvements, simulated median BC concentration in snow agrees with observation (19.2 ng g-1) within 10%, down from -40% in the default GEOS-Chem. When the previously missed gas flaring emissions (mainly located in Russia) are included, the total BC emission in the Arctic increases by 70%. The simulated BC in snow increases by 1-7 ng g-1, with the largest improvement in Russia. The discrepancy of median BC in snow in the whole Arctic reduces from -40% to -20%. In addition, recent measurements of BC dry deposition velocity suggest that the constant deposition velocity of 0.03 cm s-1 over snow and ice used in the GEOS-Chem is too low. So we apply resistance-in-series method to calculate the dry deposition velocity over snow and ice and the resulted dry deposition velocity ranges from 0.03 to 0.24 cm s-1. However, the simulated total BC deposition flux in the Arctic and BC in snow does not change, because the increased dry deposition flux has been compensated by decreased wet deposition flux. However, the fraction of dry deposition to total deposition increases from 16% to 25%. This may affect the mixing of BC and snow particles and further affect the radative forcing of BC deposited in snow. Finally, we reduced the scavenging efficiency of BC in mixed-phase clouds to account for the effect of Wegener-Bergeron-Findeisen (WBF) process based on recent observations. The simulated BC concentration in snow increases by 10-100%, with the largest increase in Greenland (100%), Tromsø (50%), Alaska (40%), and Canadian Arctic (30%). Annual BC loading in the Arctic increases from 0.25 to 0.43 mg m-2 and the lifetime of BC increases from 9.2 to 16.3 days. This indicates that BC simulation in the Arctic is really sensitive to

  1. Arctic Sea Ice and Its Changes during the Satellite Period

    Science.gov (United States)

    Wang, X.; Liu, Y.; Key, J. R.

    2009-12-01

    Sea ice is a very important indicator and an effective modulator of regional and global climate change. Changes in sea ice will significantly affect the complex exchanges of momentum, heat, and mass between sea and the atmosphere, along with profound socio-economic influences due to its role in transportation, fisheries, hunting, polar animal habitat. Over the last two decades of the 20th century, the Arctic underwent significant changes in sea ice as part of the accelerated global warming of that period. More accurate, consistent, and detailed ice thickness, extent, and volume data are critical for a wide range of applications including climate change detection, climate modeling, and operational applications such as shipping and hazard mitigation. Satellite data provide an unprecedented opportunity to estimate and monitor Arctic sea ice routinely with relatively high spatial and temporal resolutions. In this study, a One-dimensional Thermodynamic Ice Model (OTIM) has been developed to estimate sea ice thickness based on the surface energy balance at a thermo-equilibrium state, containing all components of the surface energy balance. The OTIM has been extensively validated against submarine Upward-Looking Sonar (ULS) measurements, meteorological station measurements, and comprehensive numerical model simulations. Overall, OTIM-estimated sea ice thickness is accurate to within about 20% error when compared to submarine ULS ice thickness measurements and Canadian meteorological station measurements for ice less than 3 m. Along with sea ice extent information from the SSM/I, the Arctic sea ice volume can be estimated for the satellite period from 1984 to 2004. The OTIM has been used with satellite data from the extended Advanced Very High Resolution Radiometer (AVHRR) Polar Pathfinder (APP-x) products for the Arctic sea ice thickness, and sequentially sea ice volume estimations, and following statistical analysis of spatial and temporal distribution and trends in sea

  2. AMOP (Arctic Marine Oil Spill Program) studies reviewed

    Energy Technology Data Exchange (ETDEWEB)

    1978-06-05

    A discussion of the Arctic Marine Oil Spill Program organized in 1976 by the Canadian Federal Government includes: an Arctic Atlas compiled by Fenco Consultants Ltd. to give background information necessary for developing marine oil spill countermeasures for the Arctic north of 60/sup 0/ including the west Greenland coast and the Labrador shelf (geology, meteorology and oceanography, ice conditions, biology, and social factors); program in emergency transport of spill-combatting equipment; and the factors which influence the choice of conveyance, i.e., accessibility of the site, urgency for response, and quantity of material required; laboratory studies involving the release of oil under artificial sea ice in simulated ice formation and decay purposes to determine the interaction of crude oil and first-year sea ice; inability of companies and government to control a major spill in the Labrador Sea because of poor and inadequate transport facilities, communications, and navigational aids, severe environmental conditions, and logistics problems; and studies on the effects of oil-well blowouts in deep water, including formation of oil and gas hydrates, design of oil skimmers, the use of hovercraft, and specifications for an airborne multisensor system for oil detection in ice-infested waters.

  3. Dispersal has inhibited avian diversification in Australasian archipelagoes.

    Science.gov (United States)

    Weeks, Brian C; Claramunt, Santiago

    2014-09-22

    Different models of speciation predict contrasting patterns in the relationship between the dispersal ability of lineages and their diversification rates. This relationship is expected to be negative in isolation-limited models and positive in founder-event models. In addition, the combination of negative and positive effects of dispersal on speciation can result in higher diversification rates at intermediate levels of dispersal ability. Using molecular phylogenies to estimate diversification rates, and wing morphology to estimate dispersal ability, we analysed the influence of dispersal on diversification in the avifauna of Australasian archipelagoes. Contrary to expectations given the fragmented nature of island systems, the relationship between dispersal ability and diversification rate was monotonically negative. While multiple mechanisms could generate this pattern, they all share a phase of range expansion that is decoupled from speciation. PMID:25100701

  4. Disparities in Arctic Health

    Centers for Disease Control (CDC) Podcasts

    2008-02-04

    Life at the top of the globe is drastically different. Harsh climate devoid of sunlight part of the year, pockets of extreme poverty, and lack of physical infrastructure interfere with healthcare and public health services. Learn about the challenges of people in the Arctic and how research and the International Polar Year address them.  Created: 2/4/2008 by Emerging Infectious Diseases.   Date Released: 2/20/2008.

  5. Summer Arctic sea fog

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice, atmospheric and marine instruments during China' s First Arctic Expedition. Based on the Precious data from the expedition, it was found that in the Arctic Ocean, most part of which is covered with ice or is mixed with ice, various kinds of sea fog formed such as advection fog, radiation fog and vapor fog. Each kind has its own characteristic and mechanics of creation. In the southern part of the Arctic Ocean, due to the sufficient warm and wet flow there, it is favorable for advection fog to form,which is dense and lasts a long time. On ice cap or vast floating ice, due to the strong radiation cooling effect, stable radiating fog is likely to form. In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot, which is different from short-lasting land fog. The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is because of the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical characteristics. Sea fog is the atmospheric phenomenon of sea-air heat exchange. Especially, due to the high albedo of ice and snow surface, it is diffcult to absorb great amount of solar radiation during the polar days. Besides, ice is a poor conductor of heat; it blocks the sea-air heat exchange.The sea-air exchange is active in floating ice area where the ice is broken. The sea sends heat to the atmosphere in form of latent heat; vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange. The study also indicates that the sea also transports heat to the atmosphere in form of sensible heat when vapor fog occurs.

  6. Environmental contaminants in bald eagle eggs from the Aleutian archipelago

    Science.gov (United States)

    Anthony, R.G.; Miles, A.K.; Ricca, M.A.; Estes, J.A.

    2007-01-01

    We collected 136 fresh and unhatched eggs from bald eagle (Haliaeetus leucocephalus) nests and assessed productivity on eight islands in the Aleutian archipelago, 2000 to 2002. Egg contents were analyzed for a broad spectrum of organochlorine (OC) contaminants, mercury (Hg), and stable isotopes of carbon (??13C) and nitrogen (??15N). Concentrations of polychlorinated biphenyls (??PCBs), p,p???- dichlorodiphenyldichloroethylene (DDE), and Hg in bald eagle eggs were elevated throughout the archipelago, but the patterns of distribution differed among the various contaminants. Total PCBs were highest in areas of past military activities on Adak and Amchitka Islands, indicating local point sources of these compounds. Concentrations of DDE and Hg were higher on Amchitka Island, which was subjected to much military activity during World War II and the middle of the 20th century. Concentrations of ??PCBs also were elevated on islands with little history of military activity (e.g., Amlia, Tanaga, Buldir), suggesting non-point sources of PCBs in addition to point sources. Concentrations of DDE and Hg were highest in eagle eggs from the most western Aleutian Islands (e.g., Buldir, Kiska) and decreased eastward along the Aleutian chain. This east-to-west increase suggested a Eurasian source of contamination, possibly through global transport and atmospheric distillation and/or from migratory seabirds. Eggshell thickness and productivity of bald eagles were normal and indicative of healthy populations because concentrations of most contaminants were below threshold levels for effects on reproduction. Contrary to our predictions, contaminant concentrations were not correlated with stable isotopes of carbon (??13C) or nitrogen (??15N) in eggs. These latter findings indicate that contaminant concentrations were influenced more by point sources and geographic location than trophic status of eagles among the different islands. ?? 2007 SETAC.

  7. Northern gas : Arctic Canada and Alaska

    International Nuclear Information System (INIS)

    This paper discusses supply challenges in relation to Northern gas availability in Arctic Canada and Alaska. A background of BP Canada Energy Company was provided. It was suggested that gas from traditional North American basins would not meet demand, and that incremental sources of supply would be needed. A map of traditional and non-tradition supply sources was presented along with details of supply and infrastructure investment requirements from 2003-2025. The roles of producers, local distribution companies, pipelines and policy makers in infrastructure development were examined. Potential resources in Alaska and the Mackenzie Delta were discussed, along with details of the Mackenzie Valley Pipeline project and exploration activities. Alaska's North Slope gas resource was reviewed. Several large projects devolving from the Alaska Gas Pipeline represent an anticipated total investment of $20 billion. Various regulatory and economic conditions necessary for the successful completion of the project include the Alaska Fiscal Contract; Alaska gas provisions in the Federal Energy Bill; details of the Canadian regulatory process; and cost reductions and market outlooks. It was concluded that the Alaska Gas Pipeline would provide thousands of jobs and provide stability of long-term gas prices as well as meeting North America's energy needs. In addition, the pipeline would provide $16 billion in Canadian government revenues and $40 billion in US government revenues. The pipeline would provide 4.5 billion cubic feet per day of clean energy, with half the carbon dioxide emissions of coal. It would also provide hundreds of billions of dollars in consumer savings. tabs, figs

  8. Canadian perspectives in evaluating transparency

    International Nuclear Information System (INIS)

    The Canadian Nuclear Safety Commission's mission is to regulate the use of nuclear energy and materials to protect the health, safety, and security of Canadians and the environment, as well as to respect Canada's international commitments on the peaceful use of nuclear energy. In 2001, the CNSC established a vision to be one of the best nuclear regulators in the world and established four strategic priorities of effectiveness, transparency, excellence in staff, and efficiency. While fulfilling a very comprehensive mandate, the CNSC operates with a. very clear vision of its clientele - the Canadian people. That commitment guides every employee and every action of the CNSC and ensures a firm commitment to transparency. The presentation will begin with a brief overview of the worldwide context of transparency and transparency measurement, with a look at what lessons can be learned from other organizations and initiatives. It will look broadly at the Canadian context and the government framework that establishes transparency, including the keystone legislation of the Access to Information Act. The presentation will then focus on the Canadian Nuclear Safety Commission. The CNSC is firmly committed to putting additional measures in place to ensure transparency, which is being done concurrently with an overall organisational performance measurement system. It is within this framework that the presentation will address the transparency efforts at the CNSC as well transparency measurement activities. And, finally, the presentation will look at future directions for transparency and its measurement at the CNSC. (author)

  9. Canadian Food Irradiation Facilities

    International Nuclear Information System (INIS)

    Atomic Energy of Canada Limited (AECL) began work on the irradiation of potatoes in 1956, using spent fuel rods as the radiation source. In 1958 the first Gammacell 220, a self-contained irradiator, was designed and manufactured by AECL, and cobalt-60 was then used exclusively in the food irradiation programme. In 1960 the first food and drug clearance was obtained for potatoes. The next stage was to demonstrate to the potato industry that cobalt-60 was a safe, simple and reliable tool, and that irradiation would inhibit sprouting under field conditions. A mobile irradiator was designed and produced by AECL in 1961 to carry out this pilot-plant programme. The irradiator was mounted on a fully-equipped road trailer and spent the 1961/1962 season irradiating one million pounds of potatoes at various points in Eastern Canada. In 1965 the first commercial food irradiator was designed and built by AECL for Newfield Products, Ltd. Whilst the potato programme was under way, AECL initiated co-operative programmes with Canadian food research laboratories, using additional Gammacells. In 1960, AECL constructed an irradiation facility in a shielded room at its own plant in Ottawa for the irradiation of larger objects, such as sides of pork and stems of bananas. During 1963 the mobile irradiator, already a most useful tool, was made more versatile when its source strength was increased and it was equipped with a product cooling system and van air conditioning. Following these modifications, the unit was employed in California for the irradiation of a wide spectrum of fruits at the United States Department of Agriculture Station in Fresno. The Gammacell, mobile irradiator, shielded-room facility, the commercial food irradiator and some of the main food programmes are described in detail. There is an increasing amount of interest in irradiation by the food industry, and prospects are encouraging for future installations. (author)

  10. Melithaeidae (Coelenterata: Anthozoa) from the Indian Ocean and the Malay Archipelago

    NARCIS (Netherlands)

    Ofwegen, van L.P.

    1987-01-01

    Melithaeidae from the Indian Ocean and the Malay Archipelago are described and figured, including three new species: Clathraria maldivensis, C. omanensis and Acabaria andamanensis. A lectotype is designated for Acabaria variabilis (Hickson).

  11. A baseline study of trace metals in a coral reef sedimentary environment, Lakshadweep Archipelago

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinath, A.; Nair, S.M.; Kumar, N.C.; Jayalakshmi, K.V.; Pamalal, D.

    Surficial and core samples collected from the sedimentary microenvironments of Lakshadweep Archipelago were analysed for their trace metal contents. The synoptical relations in spatial distributions with respect to environmental conditions such as p...

  12. CRED Reson 8101 multibeam backscatter data from the islands and banks in the Mariana archipelago, 2007.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the Mariana archipelago between the U.S. Territory of Guam and Uracas Island in the Commonwealth...

  13. Study on the accident oil spill pollution in Wanshan Archipelago sea area

    International Nuclear Information System (INIS)

    This paper uses diffusion model and transfer model of instantaneous oil spilling with static point source for forecasting and studying the accident oil spilling pollution in Wanshan Archipelago sea area. The paper also presents prevention and cure measures

  14. Ecological Evaluation of Cres – Lošinj Archipelago for the Purpose of Tourism

    Directory of Open Access Journals (Sweden)

    Iva Saganić

    2008-01-01

    Full Text Available The topic of this paper is ecological evaluation of the Cres-Lošinj archipelago and the way it could be used for tourism purposes. Rapid growth of population and increasing human economic activity influence the quality of the environment. That is why the concept of sustainable development has been made, as well as new kind of tourism - eco-tourism or sustainable tourism. Today there is a small number of regions with preserved nature. The Cres-Lošinj archipelago is one of them. There is a large number of preserved plant and animal species on the archipelago, as well as some rural areas with preserved local architecture. With the development of eco-tourism, this archipelago would get the image of the area with preserved and authentic natural and cultural surroundings and healthy living environment.

  15. Canadian physical activity guidelines for adults: are Canadians aware?

    Science.gov (United States)

    Dale, Leila Pfaeffli; LeBlanc, Allana G; Orr, Krystn; Berry, Tanya; Deshpande, Sameer; Latimer-Cheung, Amy E; O'Reilly, Norm; Rhodes, Ryan E; Tremblay, Mark S; Faulkner, Guy

    2016-09-01

    The present study evaluated awareness of the Canadian Society for Exercise Physiology's 2011 Canadian Physical Activity Guidelines for Adults and assessed correlates. Reported awareness of the physical activity (PA) guidelines was 12.9% (204/1586) of the total sample surveyed. More than half (55%) self-reported meeting PA guidelines of ≥ 150 min of moderate to vigorous PA per week. Awareness of PA guidelines was significantly related to participants' level of PA (χ(2) (1) = 30.63, p < 0.001, φ = -0.14), but not to any demographic variables. PMID:27560541

  16. Chernobyl - a Canadian technical perspective

    International Nuclear Information System (INIS)

    In this report we present the design review done to date in Canada by AECL. From the Canadian point of view it covers: 1) relevant information on the Chernobyl design and the accident, both as presented by the Soviets at the Post-Accident Review Meeting (PARM) held in Vienna from August 25-29, 1986, and as deduced from publicly available Soviet documentation; and 2) details of AECL's technical review of the CANDU PHWR (Pressurized Heavy Water Reactor) against the background of the Chernobyl accident, and implications of the Chernobyl accident. Reviews of operational aspects are underway by the Canadian electrical utilities and a review by the Canadian regulatory agency (the Atomic Energy Control Board) is near completion

  17. Political Affiliation of Canadian Professors

    Directory of Open Access Journals (Sweden)

    M. Reza Nakhaie

    2008-01-01

    Full Text Available The social role of universities has been the subject of a lengthy debate as to whether those who teach in the academy are system-legitimizing conservatives or radicals helping to generate critical thinking that challenges the status quo. The aim of this paper is to evaluate political affiliations of Canadian university professors based on a national survey conducted in 2000. The study shows that Canadian professors’ political affiliation can be identified as either left or right depending on how the political orientation of political parties is conceptualized. University professors tend to vote more for the Liberal Party than other parties, and view it as centrist party. Moreover, the study highlights a complex and non-monolithic picture of the Canadian academy. University professors are not politically homogenous and party vote depends on the prestige of their university, their discipline, gender, ethnicity, marital status, generation, and agreement with liberalism.

  18. Responsible Canadian energy progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The Canadian Association of Petroleum Producers (CAPP) represents oil and gas companies throughout Canada; its members produce over 90% of Canada's natural gas and crude oil output. The aim of the Association is to improve the economics of the Canadian upstream petroleum sector in an environmentally and socially responsible way. The aim of this Responsible Canadian Energy report is to present the performance data of CAPP's members for the year 2009. Data, trends, and performance analyses are provided throughout the document. This analysis makes it possible to determine where progress has been made and where performance improvement is necessary. It also presents success stories and best practices so that other companies can learn from them how to improve their own performance. This paper provides useful information on the performance of the upstream petroleum industry in Canada and highlights where the focus should be for further improvement in its performance.

  19. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

    Directory of Open Access Journals (Sweden)

    Dennis Hanke

    2016-07-01

    Full Text Available There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV lineage (arctic-3, but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4 with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population

  20. Transnational archives: the Canadian case

    Directory of Open Access Journals (Sweden)

    Julia Creet

    2011-05-01

    Full Text Available This paper is a brief overview of the concept of the transnational archive as a counterpoint to the idea that a national archive is necessarily a locus of a static idea of nation. The Canadian national archives is used as a case study of an archives that was transnational in its inception, and one that has continued to change in its mandate and materials as a response to patterns in migration and changing notions of multiculturalism as a Canadian federal policy. It introduces the most recent formation of the transnational archive and its denizens: the genealogical archive inhabited by family historians.

  1. Patterns of DNA Barcode Variation in Canadian Marine Molluscs

    Science.gov (United States)

    Layton, Kara K.S.; Martel, André L.; Hebert, Paul DN.

    2014-01-01

    Background Molluscs are the most diverse marine phylum and this high diversity has resulted in considerable taxonomic problems. Because the number of species in Canadian oceans remains uncertain, there is a need to incorporate molecular methods into species identifications. A 648 base pair segment of the cytochrome c oxidase subunit I gene has proven useful for the identification and discovery of species in many animal lineages. While the utility of DNA barcoding in molluscs has been demonstrated in other studies, this is the first effort to construct a DNA barcode registry for marine molluscs across such a large geographic area. Methodology/Principal Findings This study examines patterns of DNA barcode variation in 227 species of Canadian marine molluscs. Intraspecific sequence divergences ranged from 0–26.4% and a barcode gap existed for most taxa. Eleven cases of relatively deep (>2%) intraspecific divergence were detected, suggesting the possible presence of overlooked species. Structural variation was detected in COI with indels found in 37 species, mostly bivalves. Some indels were present in divergent lineages, primarily in the region of the first external loop, suggesting certain areas are hotspots for change. Lastly, mean GC content varied substantially among orders (24.5%–46.5%), and showed a significant positive correlation with nearest neighbour distances. Conclusions/Significance DNA barcoding is an effective tool for the identification of Canadian marine molluscs and for revealing possible cases of overlooked species. Some species with deep intraspecific divergence showed a biogeographic partition between lineages on the Atlantic, Arctic and Pacific coasts, suggesting the role of Pleistocene glaciations in the subdivision of their populations. Indels were prevalent in the barcode region of the COI gene in bivalves and gastropods. This study highlights the efficacy of DNA barcoding for providing insights into sequence variation across a broad

  2. Proxy Constraints on a Warm, Fresh Late Cretaceous Arctic Ocean

    Science.gov (United States)

    Super, J. R.; Li, H.; Pagani, M.; Chin, K.

    2015-12-01

    The warm Late Cretaceous is thought to have been characterized by open Arctic Ocean temperatures upwards of 15°C (Jenkyns et al., 2004). The high temperatures and low equator-to-pole temperature gradient have proven difficult to reproduce in paleoclimate models, with the role of the atmospheric hydrologic cycle in heat transport being particularly uncertain. Here, sediments, coprolites and fish teeth of Santonian-Campanian age from two high-latitude mixed terrestrial and marine sections on Devon Island in the Canadian High Arctic (Chin et al., 2008) were analyzed using a suite of organic and inorganic proxies to evaluate the temperature and salinity of Arctic seawater. Surface temperature estimates were derived from TEX86 estimates of near-shore, shallow (~100 meters depth) marine sediments (Witkowski et al., 2011) and MBT-CBT estimates from terrestrial intervals and both suggest mean annual temperatures of ~20°C, consistent with previous estimates considering the more southerly location of Devon Island. The oxygen isotope composition of non-diagenetic phosphate from vertebrate coprolites and bony fish teeth were then measured, giving values ranging from +13‰ to +19‰. Assuming the TEX86 temperatures are valid and using the temperature calibration of Puceat 2010, the δ18O values of coprolites imply Arctic Ocean seawater δ18O values between -4‰ and -10‰, implying very fresh conditions. Lastly, the δD of precipitation will be estimated from the hydrogen isotope composition of higher plant leaf waxes (C-25, C-27, C-29 and C-31 n-alkanes) from both terrestrial and marine intervals. Data are used to model the salinity of seawater and the meteoric relationship between δD and δ18O, thereby helping to evaluate the northern high-latitude meteoric water line of the Late Cretaceous.

  3. Circumpolar oil-and-gas-bearing basins of the arctic part of the North American continent

    Science.gov (United States)

    Zabanbark, A.; Lobkovsky, L. I.

    2015-09-01

    Major geotectonic elements of the reviewed territory of the Arctic part of the North American continent are the Hyperborean Precambrian Platform, the Franklin folding belt, the northern part of the Precambrian Canadian platform, and the Mesozoic folding belt of Canada and Alaska. The rise of the Arctic slope of Alaska, the Beaufort Sea, and the Sverdrup basin are located in the southern margins of the Hyperborean Platform. The structure and peculiarities of development of these structural elements are genetically related to the evolution of this platform, as well as the current state of petroleum potential of the most promising exploration region of Arctic in the 21st century. The forced exploration of the Arctic regions of the United States and Canada has become an important milestone in the current development of the world energetics. Up to 100 oil, gas, and gas condensate fields have been discovered as a result of violent studies, and the potential oil and gas reserves in the Arctic part of the North American continent have been estimated to 30 billiion t and 50 trillion cubic meters, respectively. Many prospects are related to the continental slopes of all three above-mentioned basins; the total potential reserves of slopes are estimated as 10-12 billion t of oil and 20-25 trillion cubic meters of gas.

  4. Distribution of 226Ra in the Arctic Ocean and the Bering Sea and its hydrologic implications

    Institute of Scientific and Technical Information of China (English)

    邢娜; 陈敏; 黄奕普; 蔡平河; 邱雨生

    2003-01-01

    Radium-226 (226Ra) activities were measured in the surface water samples collected from the Arctic Ocean and the Bering Sea during the First Chinese National Arctic Research Expedition. The results showed that 226Ra concentrations in the surface water ranged from 0.28 to 1.56 Bq/m3 with an average of 0.76 Bq/m3 in the Arctic Ocean, and from 0.25 to 1.26 Bq/m3 with an average of 0.71 Bq/m3 in the Bering Sea. The values were obviously lower than those from open oceans in middle and low latitudes, indicating that the study area may be partly influenced by sea ice meltwater. In the Bering Sea, 226Ra in the surface water decreased northward, probably as a result of the exchange between the 226Ra-deficientsea ice meltwater and the 226Ra-rich Pacific water. In the Arctic Ocean, 226Ra in the surface water increased northward and eastward. This spatial distributionof 226Ra reflected the variation of the 226Ra-enriched river component in the water mass of the Arctic Ocean. The vertical profiles of 226Ra in the Canadian Basin showed a concentration maximum at 200 m, which could be attributed to the inputs of the Pacific water or/and the bottom shelf water with high 226Ra concentration. This conclusion was consistent with the results from 2H, 18O tracers.

  5. AMAP Assessment 2013: Arctic Ocean acidification

    Science.gov (United States)

    2013-01-01

    This assessment report presents the results of the 2013 AMAP Assessment of Arctic Ocean Acidification (AOA). This is the first such assessment dealing with AOA from an Arctic-wide perspective, and complements several assessments that AMAP has delivered over the past ten years concerning the effects of climate change on Arctic ecosystems and people. The Arctic Monitoring and Assessment Programme (AMAP) is a group working under the Arctic Council. The Arctic Council Ministers have requested AMAP to: - produce integrated assessment reports on the status and trends of the conditions of the Arctic ecosystems;

  6. Arctic Submarine Slope Stability

    Science.gov (United States)

    Winkelmann, D.; Geissler, W.

    2010-12-01

    Submarine landsliding represents aside submarine earthquakes major natural hazard to coastal and sea-floor infrastructure as well as to coastal communities due to their ability to generate large-scale tsunamis with their socio-economic consequences. The investigation of submarine landslides, their conditions and trigger mechanisms, recurrence rates and potential impact remains an important task for the evaluation of risks in coastal management and offshore industrial activities. In the light of a changing globe with warming oceans and rising sea-level accompanied by increasing human population along coasts and enhanced near- and offshore activities, slope stability issues gain more importance than ever before. The Arctic exhibits the most rapid and drastic changes and is predicted to change even faster. Aside rising air temperatures, enhanced inflow of less cooled Atlantic water into the Arctic Ocean reduces sea-ice cover and warms the surroundings. Slope stability is challenged considering large areas of permafrost and hydrates. The Hinlopen/Yermak Megaslide (HYM) north of Svalbard is the first and so far only reported large-scale submarine landslide in the Arctic Ocean. The HYM exhibits the highest headwalls that have been found on siliciclastic margins. With more than 10.000 square kilometer areal extent and app. 2.400 cubic kilometer of involved sedimentary material, it is one of the largest exposed submarine slides worldwide. Geometry and age put this slide in a special position in discussing submarine slope stability on glaciated continental margins. The HYM occurred 30 ka ago, when the global sea-level dropped by app. 50 m within less than one millennium due to rapid onset of global glaciation. It probably caused a tsunami with circum-Arctic impact and wave heights exceeding 130 meters. The HYM affected the slope stability field in its neighbourhood by removal of support. Post-megaslide slope instability as expressed in creeping and smaller-scaled slides are

  7. a New Japanese Project for Arctic Climate Change Research - Grene Arctic - (Invited)

    Science.gov (United States)

    Enomoto, H.

    2013-12-01

    A new Arctic Climate Change Research Project 'Rapid Change of the Arctic Climate System and its Global Influences' has started in 2011 for a five years project. GRENE-Arctic project is an initiative of Arctic study by more than 30 Japanese universities and institutes as the flame work of GRENE (Green Network of Excellence) of MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan). The GRENE-Arctic project set four strategic research targets: 1. Understanding the mechanism of warming amplification in the Arctic 2. Understanding the Arctic system for global climate and future change 3. Evaluation of the effects of Arctic change on weather in Japan, marine ecosystems and fisheries 4. Prediction of sea Ice distribution and Arctic sea routes This project aims to realize the strategic research targets by executing following studies: -Improvement of coupled general circulation models based on validations of the Arctic climate reproducibility and on mechanism analyses of the Arctic climate change and variability -The role of Arctic cryosphere in the global change -Change in terrestrial ecosystem of pan-Arctic and its effect on climate -Studies on greenhouse gas cycles in the Arctic and their responses to climate change -Atmospheric studies on Arctic change and its global impacts -Ecosystem studies of the Arctic ocean declining Sea ice -Projection of Arctic Sea ice responding to availability of Arctic sea route (* ** ***) *Changes in the Arctic ocean and mechanisms on catastrophic reduction of Arctic sea ice cover **Coordinated observational and modeling studies on the basic structure and variability of the Arctic sea ice-ocean system ***Sea ice prediction and construction of ice navigation support system for the Arctic sea route. Although GRENE Arctic project aims to product scientific contribution in a concentrated program during 2011-2016, Japanese Arctic research community established Japan Consortium for Arctic Environmental Research (JCAR) in May

  8. Active mud volcanoes on the continental slope of the Canadian Beaufort Sea

    Science.gov (United States)

    Paull, C. K.; Dallimore, S. R.; Caress, D. W.; Gwiazda, R.; Melling, H.; Riedel, M.; Jin, Y. K.; Hong, J. K.; Kim, Y.-G.; Graves, D.; Sherman, A.; Lundsten, E.; Anderson, K.; Lundsten, L.; Villinger, H.; Kopf, A.; Johnson, S. B.; Hughes Clarke, J.; Blasco, S.; Conway, K.; Neelands, P.; Thomas, H.; Côté, M.

    2015-09-01

    Morphologic features, 600-1100 m across and elevated up to 30 m above the surrounding seafloor, interpreted to be mud volcanoes were investigated on the continental slope in the Beaufort Sea in the Canadian Arctic. Sediment cores, detailed mapping with an autonomous underwater vehicle, and exploration with a remotely operated vehicle show that these are young and actively forming features experiencing ongoing eruptions. Biogenic methane and low-chloride, sodium-bicarbonate-rich waters are extruded with warm sediment that accumulates to form cones and low-relief circular plateaus. The chemical and isotopic compositions of the ascending water indicate that a mixture of meteoric water, seawater, and water from clay dehydration has played a significant role in the evolution of these fluids. The venting methane supports extensive siboglinid tubeworms communities and forms some gas hydrates within the near seafloor. We believe that these are the first documented living chemosynthetic biological communities in the continental slope of the western Arctic Ocean.

  9. Arctic charr farming

    OpenAIRE

    Brännäs, Eva; Larsson, Stefan; Saether, Björn Steinar; Siikavuopio, Sten Ivar; Thorarensen, Helgi; Sigurgeirsson, Ólafur; Jeuthe, Henrik

    2011-01-01

    The Arctic charr (Salvelinus alpinus L.) is a holarctic salmonid fish species with both landlocked and anadromous populations. In Scandinavia it is mainly found in the mountain area, but it also appears in deep and large lake further south, i.e. in the Alps. It is the northernmost freshwater fish and A. charr is generally regarded as the most cold-adapted freshwater fish. A. charr has been commercially farmed since the early 90ths and today, the total production is 3000, 2300 and 700 tonnes/y...

  10. Research with Arctic peoples

    DEFF Research Database (Denmark)

    Smith, H Sally; Bjerregaard, Peter; Chan, Hing Man;

    2006-01-01

    entitled "Research with Arctic Peoples: Unique Research Opportunities in Heart, Lung, Blood and Sleep Disorders". The meeting was international in scope with investigators from Greenland, Iceland and Russia, as well as Canada and the United States. Multiple health agencies from Canada and the United States...... sent representatives. Also attending were representatives from the International Union for Circumpolar Health (IUCH) and the National Indian Health Board. The working group developed a set of ten recommendations related to research opportunities in heart, lung, blood and sleep disorders; obstacles and...

  11. Arctic species resilience

    DEFF Research Database (Denmark)

    Mortensen, Lars O.; Forchhammer, Mads C.; Jeppesen, Erik

    , an extensive monitoring program has been conducted in the North Eastern Greenland National Park, the Zackenberg Basic. The objective of the program is to provide long time series of data on the natural innate oscillations and plasticity of a High Arctic ecosystem. With offset in the data provided through...... and precipitation. Concurrently, phenological change has been recorded in a wide range of plants and animals, with climate change seemingly being the primary driver of these changes. A major concern is whether species and biological systems embrace the plasticity in their phenological responses needed for tracking...

  12. New insights into Arctic paleogeography and tectonics from U-Pb detrital zircon geochronology

    Science.gov (United States)

    Miller, E.L.; Toro, J.; Gehrels, G.; Amato, J.M.; Prokopiev, A.; Tuchkova, M.I.; Akinin, V.V.; Dumitru, T.A.; Moore, T.E.; Cecile, M.P.

    2006-01-01

    To test existing models for the formation of the Amerasian Basin, detrital zircon suites from 12 samples of Triassic sandstone from the circum-Arctic region were dated by laser ablation-inductively coupled plasma-mass spectrometry (ICP-MS). The northern Verkhoyansk (NE Russia) has Permo-Carboniferous (265-320 Ma) and Cambro-Silurian (410-505 Ma) zircon populations derived via river systems from the active Baikal Mountain region along the southern Siberian craton. Chukotka, Wrangel Island (Russia), and the Lisburne Hills (western Alaska) also have Permo-Carboniferous (280-330 Ma) and late Precambrian-Silurian (420-580 Ma) zircons in addition to Permo-Triassic (235-265 Ma), Devonian (340-390 Ma), and late Precambrian (1000-1300 Ma) zircons. These ages suggest at least partial derivation from the Taimyr, Siberian Trap, and/ or east Urals regions of Arctic Russia. The northerly derived Ivishak Formation (Sadlerochit Mountains, Alaska) and Pat Bay Formation (Sverdrup Basin, Canada) are dominated by Cambrian-latest Precambrian (500-600 Ma) and 445-490 Ma zircons. Permo-Carboniferous and Permo-Triassic zircons are absent. The Bjorne Formation (Sverdrup Basin), derived from the south, differs from other samples studied with mostly 1130-1240 Ma and older Precambrian zircons in addition to 430-470 Ma zircons. The most popular tectonic model for the origin of the Amerasian Basin involves counterclockwise rotation of the Arctic Alaska-Chukotka microplate away from the Canadian Arctic margin. The detrital zircon data suggest that the Chukotka part of the microplate originated closer to the Taimyr and Verkhoyansk, east of the Polar Urals of Russia, and not from the Canadian Arctic. Copyright 2006 by the American Geophysical Union.

  13. Canadian Postcolonialism: Recovering British Roots

    Science.gov (United States)

    Doughty, Howard A.

    2005-01-01

    The field of Postcolonial Studies is one of the academic fashions that has arisen in an attempt to amend or replace radical theories of social power since the alleged discrediting of Marxism. The Canadian case is more ambiguous. Postcolonialism, already an essentially contested concept, is especially conflicted where Canada is concerned. Canada…

  14. Canadian Government Electronic Information Policy.

    Science.gov (United States)

    Nilsen, Kirsti

    1993-01-01

    Examines development and evolution of Canadian government information policy in response to issues of preservation of data, information industry involvement in government data development and marketing, role of Crown copyright, and public access to government information in electronic formats. Six key information policy instruments are also…

  15. Universal values of Canadian astronauts

    Science.gov (United States)

    Brcic, Jelena; Della-Rossa, Irina

    2012-11-01

    Values are desirable, trans-situational goals, varying in importance, that guide behavior. Research has demonstrated that universal values may alter in importance as a result of major life events. The present study examines the effect of spaceflight and the demands of astronauts' job position as life circumstances that affect value priorities. We employed thematic content analysis for references to Schwartz's well-established value markers in narratives (media interviews, journals, and pre-flight interviews) of seven Canadian astronauts and compared the results to the values of National Aeronautics and Space Administration (NASA) and Russian Space Agency (RKA) astronauts. Space flight did alter the level of importance of Canadian astronauts' values. We found a U-shaped pattern for the values of Achievement and Tradition before, during, and after flight, and a linear decrease in the value of Stimulation. The most frequently mentioned values were Achievement, Universalism, Security, and Self-Direction. Achievement and Self Direction are also within the top 4 values of all other astronauts; however, Universalism was significantly higher among the Canadian astronauts. Within the value hierarchy of Canadian astronauts, Security was the third most frequently mentioned value, while it is in seventh place for all other astronauts. Interestingly, the most often mentioned value marker (sub-category) in this category was Patriotism. The findings have important implications in understanding multi-national crew relations during training, flight, and reintegration into society.

  16. Nuclear regulation - the Canadian approach

    International Nuclear Information System (INIS)

    Although the Atomic Energy Control Board was established 35 years ago the basic philosophy of nuclear regulation in Canada and the underlying principles of the regulatory process remain essentially unchanged. This paper outlines the Canadian approach to nuclear regulation and explains in practical terms how the principles of regulation are applied. (author)

  17. State of the Arctic Environment

    International Nuclear Information System (INIS)

    The Arctic environment, covering about 21 million km2, is in this connection regarded as the area north of the Arctic Circle. General biological and physical features of the terrestrial and freshwater environments of the Arctic are briefly described, but most effort is put into a description of the marine part which constitutes about two-thirds of the total Arctic environment. General oceanography and morphological characteristics are included; e.g. that the continental shelf surrounding the Arctic deep water basins covers approximately 36% of the surface areas of Arctic waters, but contains only 2% of the total water masses. Blowout accident may release thousands of tons of oil per day and last for months. They occur statistically very seldom, but the magnitude underlines the necessity of an efficient oil spill contingency as well as sound safety and quality assurance procedures. Contingency plans should be coordinated and regularly evaluated through simulated and practical tests of performance. Arctic conditions demand alternative measures compared to those otherwise used for oil spill prevention and clean-up. New concepts or optimization of existing mechanical equipment is necessary. Chemical and thermal methods should be evaluated for efficiency and possible environmental effects. Both due to regular discharges of oil contaminated drilled cuttings and the possibility of a blowout or other spills, drilling operations in biological sensitive areas may be regulated to take place only during the less sensitive parts of the year. 122 refs., 8 figs., 8 tabs

  18. Promotional archipelagoes of change. Spatial analysis of Dinosauro

    International Nuclear Information System (INIS)

    During the last decades, the post industrial Latin American cities have become important economic centers in the world. Their integration into the world economy helped those cities become in the favorite places for the linking functions and activities to the world nets of commerce, productions culture, etc. These urban centers which are expanding gradually into segmented developing areas have caused an apparent space duality between the private and public activities as it can be seen though the differential access to goods and services by the society. At present, there has been an increase in cultural activities which form change promoting archipelagoes subject to several dimensions of analysis. The inequity in the distribution of economic and educational resources causes unequal ways of access to consumption of these areas of cultural production, and of goods and services, what gives place to situations of social exclusion and inclusion. To understand this fact related to money behavior, we have selected an area situated in the northwest of Cordoba capital city, in Argentina, which is a shopping mall called Dinosaurio Group. In this essay we present an exploration into the conflicts caused to the cities through the expansion of the segmented urban centers, promoters of change, and its relationship with the public and private space.

  19. Assessment of Satellite Precipitation Products in the Philippine Archipelago

    Science.gov (United States)

    Ramos, M. D.; Tendencia, E.; Espana, K.; Sabido, J.; Bagtasa, G.

    2016-06-01

    Precipitation is the most important weather parameter in the Philippines. Made up of more than 7100 islands, the Philippine archipelago is an agricultural country that depends on rain-fed crops. Located in the western rim of the North West Pacific Ocean, this tropical island country is very vulnerable to tropical cyclones that lead to severe flooding events. Recently, satellite-based precipitation estimates have improved significantly and can serve as alternatives to ground-based observations. These data can be used to fill data gaps not only for climatic studies, but can also be utilized for disaster risk reduction and management activities. This study characterized the statistical errors of daily precipitation from four satellite-based rainfall products from (1) the Tropical Rainfall Measuring Mission (TRMM), (2) the CPC Morphing technique (CMORPH) of NOAA and (3) the Global Satellite Mapping of Precipitation (GSMAP) and (4) Precipitation Estimation from Remotely Sensed information using Artificial Neural Networks (PERSIANN). Precipitation data were compared to 52 synoptic weather stations located all over the Philippines. Results show GSMAP to have over all lower bias and CMORPH with lowest Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). In addition, a dichotomous rainfall test reveals GSMAP and CMORPH have low Proportion Correct (PC) for convective and stratiform rainclouds, respectively. TRMM consistently showed high PC for almost all raincloud types. Moreover, all four satellite precipitation showed high Correct Negatives (CN) values for the north-western part of the country during the North-East monsoon and spring monsoonal transition periods.

  20. The coastal fishes and fisheries of the Socotra Archipelago, Yemen.

    Science.gov (United States)

    Zajonz, Uwe; Lavergne, Edouard; Klaus, Rebecca; Krupp, Friedhelm; Aideed, Moteah Sheikh; Saeed, Fouad Naseeb

    2016-04-30

    The Socotra Archipelago is situated in the Gulf of Aden where tropical and "pseudo-temperate" conditions combine to create a unique marine ecosystem. The diversity, ecology, productivity and fisheries of the coastal fish assemblages are still relatively understudied and no update of the scientific knowledge existed. The islands support unique coastal and coral-associated fish assemblages in spite of the limited biogenic reef frameworks. Fish diversity is the highest among comparable Arabian eco-regions, and fish biomass productivity high too by Indian Ocean standards. The production of the once traditionally-managed small-scale fishery is severely declining and whether it is sustainable nowadays is extremely doubtful. At a time when Yemen is torn apart by a severe political and humanitarian crisis it is timely to review and update the current state of knowledge for scientists and managers, and thereby ease access to existing information, facilitating follow-on studies and evidence-based conservation and fisheries management. PMID:26795842

  1. Factors controlling phosphorus release from sediments in coastal archipelago areas.

    Science.gov (United States)

    Puttonen, Irma; Kohonen, Tuula; Mattila, Johanna

    2016-07-15

    In coastal archipelago areas of the northern Baltic Sea, significantly higher phosphate concentrations (6.0±4.5μmol/l, mean±SD) were measured in water samples close to the sediment surface compared with those from 1m above the seafloor (1.6±2.0μmol/l). The results indicated notable phosphate release from sediments under the bottom water oxygen concentrations of up to 250μmol/l, especially in areas that had experienced recent temporal fluctuation between oxic and hypoxic/anoxic conditions. No single factor alone was found to control the elevated PO4-P concentrations in the near-bottom water. In addition to the oxygen in the water, the contents of potentially mobile phosphorus fractions, grain-size, the organic content at the sediment surface, and the water depth were all important factors controlling the internal loading of phosphorus. The complexity of this process needs to be accounted for in assessments of the internal loading of phosphorus and in potential mitigation plans. PMID:27184132

  2. Characterisation of a basin mire in the Azores archipelago

    Directory of Open Access Journals (Sweden)

    E. Dias

    2007-10-01

    Full Text Available The Azores archipelago in the North Atlantic is an extremely important area for biodiversity because it is rich in rare species and habitats, and almost undisturbed. The Lagoa do Madruga is a small basin mire located at 956 m a.s.l. on Santa Bárbara Mountain, Terceira Island. It is an extremely good example of a peatland type that was first discovered in 1998, and has not previously been described in the international literature. This paper provides baseline information on its flora, vegetation communities, structure and hydrology. Thirty-one plant species including eight Sphagnum species and nine endemic vascular plants have been recorded, and four plant communities are distinguished. The maximum peat depth is three metres. The mire receives flowing water from its margins and from a small stream entering at its eastern end, in addition to intercepted precipitation and fog. The accumulated water forms pools and soakways which feed other wetlands downstream. The conservation status of the mire is good, but it is subject to increasing pressure from garbage generated during maintenance operations at a nearby antenna array.

  3. Landslides density map of S. Miguel Island, Azores archipelago

    Directory of Open Access Journals (Sweden)

    P. Valadão

    2002-01-01

    Full Text Available The Azores archipelago is located in the Atlantic Ocean and is composed of nine volcanic islands. S. Miguel, the largest one, is formed by three active, E-W trending, trachytic central volcanoes with caldera (Sete Cidades, Fogo and Furnas. Chains of basaltic cinder cones link those major volcanic structures. An inactive trachytic central volcano (Povoação and an old basaltic volcanic complex (Nordeste comprise the easternmost part of the island. Since the settlement of the island early in the 15th century, several destructive landslides triggered by catastrophic rainfall episodes, earthquakes and volcanic eruptions occurred in different areas of S. Miguel. One unique event killed thousands of people in 1522. Houses and bridges were destroyed, roads were cut, communications, water and energy supply systems became frequently disrupted and areas of fertile land were often buried by mud. Based on (1 historical documents, (2 aerial photographs and (3 field observations, landslide sites were plotted on a topographic map, in order to establish a landslide density map for the island. Data obtained showed that landslide hazard is higher on (1 the main central volcanoes where the thickness of unconsolidated pyroclastic deposits is considerable high and (2 the old basaltic volcanic complex, marked by deep gullies developed on thick sequences of lava flows. In these areas, caldera walls, fault scarps, steep valley margins and sea cliffs are potentially hazardous.

  4. Arctic Ocean UNCLOS Article 76 Work for Greenland Starts on Land

    Science.gov (United States)

    Dahl-Jensen, T.; Marcussen, C.; Jackson, R.; Voss, P.

    2005-12-01

    One of the most lonely and desolate stretches of coastline on the planet has become the target for UNCLOS article 76 related research. The Danish Continental Shelf Project has launched a work program to investigate the possibilities for Greenland to claim an area outside the 200 nm limit in the Arctic Ocean. The role of the Lomonosov Ridge as a Natural Prolongation of Greenland/Canada is an important issue, and in order to better evaluate the connection between Greenland and the Lomonosov Ridge the nature of not only the ridge but also of Northern Greenland is the target of deep crustal investigations. The North Greenland Fold belt covers the ice-free part of North Greenland and continues west in the Canadian Arctic. The foldbelt was formed during the Ellesmerian orogeny, where sediments from the Franklinian Basin where compressed and deformed. The deep structure of basin and its subsequent closure are broadly unknown. Three broad band earthquake seismological stations where installed in North Greenland to supplement the existing stations at Alert (Canada) and Station Nord to the east, and the first data was available summer 2005. Crustal thickness data from these first results are presented. Plans for the spring 2006 consist of wide-angle acquisition on the sea ice from the Greenland-Canadian mainland out onto the Lomonosov Ridge, a joint Danish - Canadian project with a 400 km long profile over difficult ice conditions, 18 tons of explosives, three helicopters, a Twin Otter and about 30 participants.

  5. Comparison of Magnetic and Moessbauer Results Obtained for Palaeozoic Rocks of Hornsund, Southern Spitsbergen, Arctic

    International Nuclear Information System (INIS)

    This analysis was performed as a part of the palaeomagnetic project focused on the reconstruction of the palaeogeographic position of the Svalbard Archipelago and adjacent crustal units (European Arctic) in the Palaeozoic and Mesozoic. Three rock formations | Cambrian, Devonian and Carboniferous were sampled in the area of Hornsund, southern Spitsbergen. The main aim of the presented study is to identify ferromagnetic minerals (sensu lato) - the carriers of the natural remanent magnetisation in the investigated rocks. A wide range of magnetic methods were used: the Lowrie tests, unblocking temperatures determinations and the measurement of coercivity spectra as well as the Moessbauer studies. In Devonian and Carboniferous samples all applied methods indicate the domination of the hematite natural remanent magnetisation carrier. In Cambrian rocks magnetic measurements reveal a mixture of ferromagnetic (sensu lato) minerals with varying coercivities and unblocking temperatures. The Moessbauer data improve the identification, suggesting that in Cambrian rocks the carrier of the dominating natural remanent magnetisation component is maghemite. (authors)

  6. Impacts of a Warming Arctic. Arctic Climate Impact Assessment

    International Nuclear Information System (INIS)

    The Arctic is warming much more rapidly than previously known, at nearly twice the rate as the rest of the globe, and increasing greenhouse gases from human activities are projected to make it warmer still, according to an unprecedented four-year scientific study of the region conducted by an international team of 300 scientists. At least half the summer sea ice in the Arctic is projected to melt by the end of this century, along with a significant portion of the Greenland Ice Sheet, as the region is projected to warm an additional 4-7C by the year 2100. These changes will have major global impacts, such as contributing to global sea-level rise and intensifying global warming, according to the final report of the Arctic Climate Impact Assessment (ACIA). The assessment was commissioned by the Arctic Council (a ministerial intergovernmental forum comprised of the eight Arctic countries and six Indigenous Peoples organizations) and the International Arctic Science Committee (an international scientific organization appointed by 18 national academies of science). The assessment's projections are based on a moderate estimate of future emissions of carbon dioxide and other greenhouse gases, and incorporate results from five major global climate models used by the Intergovernmental Panel on Climate Change (IPCC)

  7. SCICEX: Submarine Arctic Science Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Submarine Arctic Science Program, SCICEX, is a federal interagency collaboration among the operational Navy, research agencies, and the marine research...

  8. Arctic Terrestrial Biodiversity Monitoring Plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.;

    -Terrestrial Plan/the Plan) as the framework for coordinated, long-term Arctic terrestrial biodiversity monitoring. The goal of the CBMP-Terrestrial Plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect, understand and report on long......-term change in Arctic terrestrial ecosystems and biodiversity. The CBMP-Terrestrial Plan aims to address these priority management questions: 1. What are the status, distribution, and conditions of terrestrial focal species, populations, communities, and landscapes/ecosystems and key processes...... network of scientists, conservation organizations, government agencies, Permanent Participants Arctic community experts and leaders. Using an ecosystem-based monitoring approach which includes species, ecological functions, ecosystems, their interactions, and potential drivers, the CBMP focuses on...

  9. Development of arctic wind technology

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H.; Marjaniemi, M.; Antikainen, P. [VTT Energy, Espoo (Finland)

    1998-10-01

    The climatic conditions of Lapland set special technical requirements for wind power production. The most difficult problem regarding wind power production in arctic regions is the build-up of hard and rime ice on structures of the machine

  10. Comparative phylogeography of oceanic archipelagos: Hotspots for inferences of evolutionary process

    Science.gov (United States)

    Shaw, Kerry L.; Gillespie, Rosemary G.

    2016-01-01

    Remote island archipelagos offer superb opportunities to study the evolution of community assembly because of their relatively young and simple communities where speciation contributes to the origin and evolution of community structure. There is great potential for common phylogeographic patterns among remote archipelagos that originate through hotspot volcanism, particularly when the islands formed are spatially isolated and linearly arranged. The progression rule is characterized by a phylogeographic concordance between island age and lineage age in a species radiation. Progression is most likely to arise when a species radiation begins on an older island before the emergence of younger islands of a hotspot archipelago. In the simplest form of progression, colonization of younger islands as they emerge and offer appropriate habitat, is coincident with cladogenesis. In this paper, we review recent discoveries of the progression rule on seven hotspot archipelagos. We then discuss advantages that progression offers to the study of community assembly, and insights that community dynamics may offer toward understanding the evolution of progression. We describe results from two compelling cases of progression where the mosaic genome may offer insights into contrasting demographic histories that shed light on mechanisms of speciation and progression on remote archipelagos. PMID:27432948

  11. Saalian to Holocene Paleoenvironmental History Documented in Permafrost Sequences of Arctic Siberia (New Siberian Archipelago, Bolshoy Lyakhovsky Island)

    Science.gov (United States)

    Schirrmeister, L.; Andreev, A.; Grosse, G.; Meyer, H.

    2004-12-01

    Permafrost sequences exposed at the coast of the southernmost New Siberian Island are studied multidisciplinary by a Russian-German team using cryolithology, sedimentology, geochronology, geochemistry of ground ice, and bioindicators. The oldest horizon contains remains of a periglacial reworked Palaeogene weathering crust as proved by the occurrence of weathering products like kaolinite and montmorillonite. Separate epigenetic ice wedges and the absence of bio-indicators also characterize this horizon. Saalian climate fluctuations are documented in two sedimentological units formed c. 200-120 ky ago. The lower unit (c. 200-170 ky) is very ice-rich and contains large ice wedges. Cryolithologically it is similar to the Late Pleistocene deposits of the so-called Ice Complex. The lower part of this unit contains pollen assemblages of sparse grass-sedge vegetation and reflects stadial environment. The upper part of this ice-rich unit is characterized by pollen spectra of dense grass-dominated tundra reflecting interstadial conditions. This Saalian Ice Complex deposits were eroded and covered by a younger Saalian unit (c. 170-120 ky). Well-sorted fine-grained sand contains less ground ice and pollen spectra of sparse grass-sedge dominated vegetation assigned to a Late Saalian Stadial. The accumulation of these loess-like floodplain and lake deposits, and the formation of ice wedge polygon systems took place under extremely cold and dry conditions. The following unit, assigned to the Eemian Interglacial, contains large ice wedge casts with many paleoecological evidences of interglacial environment. Humid and warm conditions resulted in thawing of ice wedge systems and the formation of ice wedge casts and thermokarst lakes. Subsequently, the permafrost sequences were locally eroded down to the old Ice Complex deposits. Lacustrine and loess-like floodplain deposits with ice wedge polygon systems were accumulated again during the Early Weichselian stadial (c. 100-50 ky) under extremely cold and dry conditions. They consist of fine-grained, well-sorted sands with rare grass and sedge pollen. These deposits turn gradually into an about 20 m thick ice-rich Late Weichselian Ice Complex horizon, dated 50-28 ky BP and containing the pollen spectra of typical mammoth tundra-steppe associations. The Ice Complex contains big ice wedge polygon systems. It represents a swampy, poorly drained habitat, which existed under extreme continental climate. Whereas peaty deposits of the Middle Weichselian Interstadial (c. 40-30 ky BP) occur regularly, Late Weichselian Stadial sequences were not found. The Ice Complex deposits appear to be eroded during that time and covered by Late Glacial/Holocene deposits afterwards. Active thermokarst processes during the Late Pleistocene/Holocene transition (c. 12-10 ky BP) resulted in the formation of large thermokarst depressions. New ice wedge polygon systems were formed during the Late Holocene climate deterioration. The Late Pleistocene/Holocene transition, including the Aller\\o d warming and Younger Dryas cooling events, is preserved within lacustrine thermokarst deposits in a thermokarst depression flanking the Late Weichselian Ice Complex sequences.

  12. The prospects for Canadian uranium

    International Nuclear Information System (INIS)

    The 1980s have seen a decline in markets for uranium concentrate, largely as a result of falling estimates for reactor fuel requirements and rising inventories. Spot market prices fell to $44 in September 1982, but have since risen back to $60. World production also fell in 1982 and is not expected to increase significantly before 1990. Some opportunities exist for Canadian producers with new low-cost deposits to replace high-cost producers in Canada and other countries, particularly the United States. There will be strong competition between Canadian producers as well as from Australia. Australia's reserves are somewhat larger than Canada's, although the reported ore grades tend to be lower than those of Saskatchewan

  13. The Canadian safeguards support program

    International Nuclear Information System (INIS)

    Canada supports international safeguards as a means by which the proliferation of nuclear weapons can be discouraged. Canada recognizes that,to meet that the IAEA must have effective safeguards techniques and the active cooperation of Member States. Therefore the Canadian Government decided in 1976 to initiate a program in support of IAEA safeguards, known as the Canadian Safeguards Support Program (CSSP). The CSSP is funded and administered by the Atomic Energy Control Board (AECB). The CSSP is a co-ordinated program for the development and the application of safeguards instruments and techniques for nuclear facilities and materials on behalf of the IAEA and also in support of Canada's own national nuclear material safeguards system, implemented by the AECB. (author)

  14. Exporting the Canadian licensing program

    International Nuclear Information System (INIS)

    This paper deals with the problems of an overseas regulatory agency in licensing a Canadian-supplied nuclear plant which is referenced to a plant in Canada. Firstly, the general problems associated with the use of a reference plant are discussed. This is followed by a discussion of specific problems which arise from the licensing practices in Canada. The paper concludes with recommendations to simplify the task of demonstrating the licensability of an overseas CANDU plant

  15. Canadian wind energy industry directory

    International Nuclear Information System (INIS)

    The companies and organizations involved, either directly or indirectly, in the wind energy industry in Canada, are listed in this directory. Some U.S. and international companies which are active or interested in Canadian industry activities are also listed. The first section of the directory is an alphabetical listing which includes corporate descriptions, company logos, addresses, phone and fax numbers, e-mail addresses and contact names. The second section contains 54 categories of products and services associated with the industry

  16. Canadian Content in Video Games

    OpenAIRE

    Paul, Leonard

    2005-01-01

    THEME: Internationalism: Worlds at Play Topics: Internationalism, Identity in Gaming and Learning to Play Abstract: How does Canada fit into the global cultural context of video games? This paper investigates the culture being reflected in video games being produced in Canada as Canada is one of the world's leading producers of video games. It examines the how Canadian culture is represented in current new media artistic output against the culture, or lack of culture, being represented in vid...

  17. Viticultural zoning of Graciosa island of the Azores archipelago - Portugal

    Science.gov (United States)

    Madruga, João; Reis, Francisco; Felipe, João; Azevedo, Eduardo; Pinheiro, Jorge

    2016-04-01

    The management and sustainability of the traditional vineyards of the Azores settled on lava field terrains is strongly affected by practical limitations of mechanization and high demand on man labor imposed by the typical micro parcel structure of the vineyards. In a recent macrozoning approach study Madruga et al (2015) showed that besides the traditional vineyards there are significant areas in some of the Azores islands whose soils, climate and physiographic characteristics indicate a potential for the development of new vineyard areas offering conditions for better management and sustainability. The objective of this study was to conduct a detailed viticultural zoning at the level of the small mapscale (smaller than 1:25,000), for the island of Graciosa where, besides the traditional lava field terroir, there are also some localized experiences of grapevine production over normal soils, offering thus some comparative information on this type of production conditions. The zoning approach for the present study was based in a geographic information system (GIS) analysis incorporating factors related to climate and topography which was then combined with the soil mapping units fulfilling the suitable criteria concerning the soil properties taken as the most relevant for viticulture, being the result a map of homogeneous environmental units. The climatic zoning examined the direct quantitative variables (precipitation, temperature, evaporation) in relation to climate index, bioclimatic and viticultural specific values. Topography (elevation, slope, aspect, orientation) was analyzed based on the tridimensional models of the islands in GIS to include the best slopes for the mechanization of the vineyard cultural operations (0-15%). Soils were analyzed based on data and soil map units as defined in the soil surveys of the Azores archipelago. The soil properties taken for the analysis and definition of the potential vineyard areas were drainage, water holding capacity

  18. Providing cleaner air to Canadians

    International Nuclear Information System (INIS)

    This booklet is designed to explain salient aspects of the Ozone Annex, negotiated and signed recently by Canada and the United States, in a joint effort to improve air quality in North America. By significantly reducing the transboundary flows of air pollutants that cause smog, the Ozone Annex will benefit some 16 million people in central and eastern Canada and provide an example for a future round of negotiations to address concerns of the millions of Canadians and Americans who live in the border area between British Columbia and Washington State. The brochure provide summaries of the Canadian and American commitments, focusing on transportation, monitoring and reporting. The Ozone Annex complements other air quality initiatives by the Government of Canada enacted under the Environmental Protection Act, 1999. These measures include regulations to reduce sulphur content to 30 parts per million by Jan 1, 2005; proposing to restrict toxic particulate matter (PM) to less than 10 microns; establishing daily smog forecasts in the Maritimes and committing to a national program built upon existing smog advisories and forecasts in Quebec, Ontario and British Columbia; and investing in more clean air research through the newly created Canadian Foundation for Climate and Atmospheric Sciences

  19. Canadian fusion fuels technology project

    International Nuclear Information System (INIS)

    The Canadian Fusion Fuels Technology Project was launched in 1982 to coordinate Canada's provision of fusion fuels technology to international fusion power development programs. The project has a mandate to extend and adapt existing Canadian tritium technologies for use in international fusion power development programs. 1985-86 represents the fourth year of the first five-year term of the Canadian Fusion Fuels Technology Project (CFFTP). This reporting period coincides with an increasing trend in global fusion R and D to direct more effort towards the management of tritium. This has resulted in an increased linking of CFFTP activities and objectives with those of facilities abroad. In this way there has been a continuing achievement resulting from CFFTP efforts to have cooperative R and D and service activities with organizations abroad. All of this is aided by the cooperative international atmosphere within the fusion community. This report summarizes our past year and provides some highlights of the upcoming year 1986/87, which is the final year of the first five-year phase of the program. AECL (representing the Federal Government), the Ministry of Energy (representing Ontario) and Ontario Hydro, have given formal indication of their intent to continue with a second five-year program. Plans for the second phase will continue to emphasize tritium technology and remote handling

  20. Mercury in Canadian crude oil

    International Nuclear Information System (INIS)

    Estimates for average mercury concentrations in crude oil range widely from 10 ng/g of oil to 3,500 ng/g of oil. With such a broad range of estimates, it is difficult to determine the contributions of the petroleum sector to the total budget of mercury emissions. In response to concerns that the combustion of petroleum products may be a major source of air-borne mercury pollution, Environment Canada and the Canadian Petroleum Products Institute has undertaken a survey of the average total mercury concentration in crude oil processed in Canadian refineries. In order to calculate the potential upper limit of total mercury in all refined products, samples of more than 30 different types of crude oil collected from refineries were measured for their concentration of mercury as it enters into a refinery before processing. High temperature combustion, cold vapour atomic absorption and cold vapour atomic fluorescence were the techniques used to quantify mercury in the samples. The results of the study provide information on the total mass of mercury present in crude oil processed in Canada each year. Results can be used to determine the impact of vehicle exhaust emissions to the overall Canadian mercury emission budget. 17 refs., 2 tabs., 2 figs

  1. Conference summaries. Canadian Nuclear Association 29. annual conference; Canadian Nuclear Society 10. annual conference

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for 15 papers from the twenty-ninth Annual Conference of the Canadian Nuclear Association. Abstracts were also prepared for the 102 papers from the tenth Annual Conference of the Canadian Nuclear Society

  2. 77 FR 31677 - Request for Public Comment on Interagency Arctic Research Policy Committee (IARPC) Arctic...

    Science.gov (United States)

    2012-05-29

    ... TECHNOLOGY POLICY Request for Public Comment on Interagency Arctic Research Policy Committee (IARPC) Arctic Research Plan: FY2013-2017 May 22, 2012. ACTION: Request for public comment. SUMMARY: The Arctic Research and Policy Act of 1984 (ARPA), Public Law 98-373, established the Interagency Arctic Research...

  3. Are Canadian Banks Ready for Basel III?

    OpenAIRE

    Imad Kutum; Khaled Hussainey

    2014-01-01

    The purpose of this study is to analyze and test the current liquidity coverage ratio of Canadian banks’, and draw conclusions about the readiness of Canadian banks to meet Basel III regulations. Liquidity coverage ratios for six major Canadian banks were calculated using the liquid assets and liabilities listed on their balance sheets from 2009 to 2013. The actual assets that meet Basel III requirements could not be acquired, as this is private information that does not have to be released u...

  4. entering the postindustrial society: the canadian case

    OpenAIRE

    Matejko, Alexander J.

    1986-01-01

    abstract: the canadian federation is based on the substantial autonomy of the provinces constituting it, the welfare orientation of central bodies, the volunteer activities at the grass-root level, and the external policy open to the world. there are no any doubts about the genuinely democratic character of canadian internal politics or the commitment of canadians to the world peace. the economic prosperity of the country is secured by the mineral resources, good agriculture, and the intensiv...

  5. Ecological footprint of road traffic on Cres-Lošinj Archipelago

    OpenAIRE

    Hrvoje Grofelnik

    2010-01-01

    Cres-Lošinj Archipelago is the largest insular traffic unit in Northern Adriatic. The archipelago consists of two large islands, Cres and Lošinj, and 27 smaller islands located among Kvarner, Kvarnerić, Rijeka Bay and open sea. From the point of view of traffic, this area gravitates mostly toward Rijeka traffic node. Traffic development of the islands was determined in the second half of the 20th century with the development of ferry traffic and road traffic on the islands. Today, the Archipe...

  6. Content in metallic ions of wines from the Madeira and Azores archipelagos

    OpenAIRE

    Pérez Trujillo, Juan P.; Conde, José E.; Pérez Pont, Maria L.; Marques, José C.; Câmara, José S.

    2011-01-01

    This study determines for the first time Na, K, Ca, Mg, Fe, Cu, Zn, Mn, Sr, Li and Rb contents in wines from the archipelagos of Madeira and Azores (Portugal). The greater part of the mean content for the different parameters fell within the ranges described in the literature, except for sodium whose higher content may be due to the effect of marine spray. ANOVA was used to establish the metals with significant differences in mean content between the wines from both archipelagos, between tabl...

  7. Fishery of the Green Jack Caranx caballus (Osteichytes: Carangidae) in Las Perlas Archipelago, Pacific Panama

    OpenAIRE

    James M Mair; Roberto Cipriani; Guzman, Hector M; David Usan

    2012-01-01

    Green Jacks, Caranx caballus, are distributed along the Eastern Pacific coast. In Panama, C. caballus was heavily fished around Las Perlas Archipelago to sustain local markets until 2007, when the archipelago was declared a marine protected area. This first study in Panama, analyzed a sample of 4 990 individuals from Las Perlas, obtained monthly from June 2005 to June 2006, from landings at the central fish market. Average total length was 36.1±6.4cm and optimum length 38.9cm. Approximately 6...

  8. Isolation of novel psychrophilic bacteria from Arctic sea ice

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The phylogenetic diversity of culturable psychrophilic bacteria associated with sea ice from the high latitude regions of Canadian Basin and Chukchi Sea, Arctic, was investigated. A total of 34 psychropilic strains were isolated using three methods of (Ⅰ) dilution plating (at 4 ℃), (Ⅱ) bath culturing (at -1 ℃) and dilution plating, and (Ⅲ) cold shock (-20 ℃ for 24 h), bath culturing and dilution plating under aerobic conditions. Sea-ice samples were exposed to -20 ℃ for 24 h that might reduce the number of common microorganisms and encourage outgrowth of psychrophilic strains. This process might be able to be introduced to isolation psychrophilic bacteria from other environmental samples in future study. 16S rDNA nearly full-length sequence analysis revealed that psychrophilic strains felled in two phylogenetic divisions, γ-proteobacteria (in the genera Colwellia、Marinobacter、Shewanella、Glaciecola、Marinomonas and Pseudoalteromonas) and Cytophaga-Flexibacter-Bacteroides (Flavobacterium and Psychroflexus). Fifteen of bacterial isolates quite likely represented novel species (16S rDNA sequence similarity below 98%). One of strains (BSi20002) from Canadian Basin showed 100% sequence similarity to that of Marinobacter sp. ANT8277 isolated from the Antarctic Weddell sea ice, suggesting bacteria may have a bipolar distribution at the species level.

  9. The Secret of Canadian Banking: Common Sense?

    OpenAIRE

    Laurence Booth

    2009-01-01

    This article looks at the basic reasons why the Canadian banking system was recently judged by the World Economic Forum to be the soundest in the world. It does so by first examining the basic functions of a financial system and what Canadian banks are allowed to do as intermediaries within that system. It then considers the market structure of Canadian banking and the role of the Canadian government in regulating the financial system. It finishes with a discussion of the four basic managemen...

  10. Magmatism and Eurekan deformation in the High Arctic Large Igneous Province

    DEFF Research Database (Denmark)

    Tegner, Christian; Storey, Michael; Holm, Paul Martin;

    2011-01-01

    perthite feldspars and coeval resetting of Rb–Sr isotopes by hydrothermal fluids provide further support for thermal overprinting. This thermal event is interpreted as a result of compressional tectonism of the Kap Cannon Thrust Zone in which older Palaeozoic metasediments were thrusted northwards over the...... spreading in the Northeast Atlantic resulted in spreading and volcanism (61– 25 Ma) on both sides of Greenland, pushing Greenland northwards relative to North America. The tectonic setting in the High Arctic thus changed from extensional to compressional and volcanic activity was terminated. Evaluation of...... plate kinematic models shows that the relative northwards govement of Greenland culminated in the Eocene, coinciding with thermal resetting. We conclude that compression in North Greenland peaked at 49–47 Ma and coincided with the Eurekan Orogeny in a belt across the Canadian Arctic Islands and western...

  11. The Arctic policy of China and Japan

    DEFF Research Database (Denmark)

    Tonami, Aki

    2014-01-01

    At the May 2013 Arctic Council Ministerial Meeting, five Asian states, namely China, Japan, India, Singapore and South Korea, were accepted to become new Permanent Observers at the Arctic Council. Nonetheless, little attention has been paid to the Asian states and their interest in the Arctic. Most...... discussions have focused on China and the assessment of China’s interest in the Arctic is divided. This paper attempts to fill this gap by presenting and comparing the various components of the Arctic policies of China and Japan. Referring to Putnam’s model of the “two-level game” and Young’s categorization...... of Arctic stakeholders’ interests, data from policy documents and interviews with relevant stakeholders were analysed. This analysis shows the Chinese and Japanese governments are in the gradual process of consolidating their Arctic policies, but both China and Japan see the Arctic less as a...

  12. Synoptic controls on the surface energy and water budgets in sub-arctic regions of Canada

    Science.gov (United States)

    Petrone, Richard M.; Rouse, Wayne R.

    2000-08-01

    An objective hybrid classification of daily surface weather maps for central and western Canadian sub-arctic locations was used to determine their dominant synoptic conditions during the snow free period. This classification yielded seven dominant synoptic types for each location during the snowmelt and snow-free periods (20 April-7 September), accounting for 90% of the days in period. The effects of source regions were used to explain the observed air mass characteristics, and their influence on the respective study locations. Cooler, drier air masses were the most frequent at both study locations. Arctic high pressure cells to the northeast brought the coolest air to the western sub-arctic site, Trail Valley Creek (TVC), Northwest Territories, while high pressure systems approaching from the northwest brought the coolest conditions to the central sub-arctic site, Churchill, Manitoba. Sub-tropical high pressure approaching from the west-southwest brought warm air to TVC, whereas stationary high pressure to the south warmed Churchill. These synoptic regimes exerted strong controls on the precipitation and evaporation components of the water balance as observed in terms of cloud cover, radiation and precipitation and evaporation efficiencies.

  13. Prediction of a thermodynamic wave train from the monsoon to the Arctic following extreme rainfall events

    Science.gov (United States)

    Krishnamurti, T. N.; Kumar, Vinay

    2016-06-01

    This study addresses numerical prediction of atmospheric wave trains that provide a monsoonal link to the Arctic ice melt. The monsoonal link is one of several ways that heat is conveyed to the Arctic region. This study follows a detailed observational study on thermodynamic wave trains that are initiated by extreme rain events of the northern summer south Asian monsoon. These wave trains carry large values of heat content anomalies, heat transports and convergence of flux of heat. These features seem to be important candidates for the rapid melt scenario. This present study addresses numerical simulation of the extreme rains, over India and Pakistan, and the generation of thermodynamic wave trains, simulations of large heat content anomalies, heat transports along pathways and heat flux convergences, potential vorticity and the diabatic generation of potential vorticity. We compare model based simulation of many features such as precipitation, divergence and the divergent wind with those evaluated from the reanalysis fields. We have also examined the snow and ice cover data sets during and after these events. This modeling study supports our recent observational findings on the monsoonal link to the rapid Arctic ice melt of the Canadian Arctic. This numerical modeling suggests ways to interpret some recent episodes of rapid ice melts that may require a well-coordinated field experiment among atmosphere, ocean, ice and snow cover scientists. Such a well-coordinated study would sharpen our understanding of this one component of the ice melt, i.e. the monsoonal link, which appears to be fairly robust.

  14. Empirical Requirements Analysis for Mars Surface Operations Using the Flashline Mars Arctic Research Station

    Science.gov (United States)

    Clancey, William J.; Lee, Pascal; Sierhuis, Maarten; Norvig, Peter (Technical Monitor)

    2001-01-01

    Living and working on Mars will require model-based computer systems for maintaining and controlling complex life support, communication, transportation, and power systems. This technology must work properly on the first three-year mission, augmenting human autonomy, without adding-yet more complexity to be diagnosed and repaired. One design method is to work with scientists in analog (mars-like) setting to understand how they prefer to work, what constrains will be imposed by the Mars environment, and how to ameliorate difficulties. We describe how we are using empirical requirements analysis to prototype model-based tools at a research station in the High Canadian Arctic.

  15. Arctic Landscape Within Reach

    Science.gov (United States)

    2008-01-01

    This image, one of the first captured by NASA's Phoenix Mars Lander, shows flat ground strewn with tiny pebbles and marked by small-scale polygonal cracking, a pattern seen widely in Martian high latitudes and also observed in permafrost terrains on Earth. The polygonal cracking is believed to have resulted from seasonal contraction and expansion of surface ice. Phoenix touched down on the Red Planet at 4:53 p.m. Pacific Time (7:53 p.m. Eastern Time), May 25, 2008, in an arctic region called Vastitas Borealis, at 68 degrees north latitude, 234 degrees east longitude. This image was acquired at the Phoenix landing site by the Surface Stereo Imager on day 1 of the mission on the surface of Mars, or Sol 0, after the May 25, 2008, landing. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. The Canadian Astronomy Data Centre

    Science.gov (United States)

    Ball, Nicholas M.; Schade, D.; Astronomy Data Centre, Canadian

    2011-01-01

    The Canadian Astronomy Data Centre (CADC) is the world's largest astronomical data center, holding over 0.5 Petabytes of information, and serving nearly 3000 astronomers worldwide. Its current data collections include BLAST, CFHT, CGPS, FUSE, Gemini, HST, JCMT, MACHO, MOST, and numerous other archives and services. It provides extensive data archiving, curation, and processing expertise, via projects such as MegaPipe, and enables substantial day-to-day collaboration between resident astronomers and computer specialists. It is a stable, powerful, persistent, and properly supported environment for the storage and processing of large volumes of data, a condition that is now absolutely vital for their science potential to be exploited by the community. Through initiatives such as the Common Archive Observation Model (CAOM), the Canadian Virtual Observatory (CVO), and the Canadian Advanced Network for Astronomical Research (CANFAR), the CADC is at the global forefront of advancing astronomical research through improved data services. The CAOM aims to provide homogeneous data access, and hence viable interoperability between a potentially unlimited number of different data collections, at many wavelengths. It is active in the definition of numerous emerging standards within the International Virtual Observatory, and several datasets are already available. The CANFAR project is an initiative to make cloud computing for storage and data-intensive processing available to the community. It does this via a Virtual Machine environment that is equivalent to managing a local desktop. Several groups are already processing science data. CADC is also at the forefront of advanced astronomical data analysis, driven by the science requirements of astronomers both locally and further afield. The emergence of 'Astroinformatics' promises to provide not only utility items like object classifications, but to directly enable new science by accessing previously undiscovered or intractable

  17. Canadian environmental sustainability indicators 2006

    International Nuclear Information System (INIS)

    In 2004, the Canadian government committed to reporting annual national indicators of air quality, greenhouse gas (GHG) emissions and freshwater quality in order to provide Canadians with more regular and consistent information on the state of the environment and how it is linked with human activities. The national air quality indicators in this report focused on human exposure to ground-level ozone and fine particulate matter (PM2.5). The report showed that from 1990 to 2004, the ozone indicator showed year-to-year variability, with an averaged increase of 0.9 per cent per year. Stations in southern Ontario reported the highest levels of ozone and PM2.5 in the country in 2004. There was no discernible upward or downward trend in PM2.5 levels at the national level for the 2000 to 2004 period, and GHG emissions rose 27 per cent from 1990 to 2004. In 2004, emissions were 35 per cent above the target to which Canada committed under the Kyoto Protocol. However, while total emissions rose, emissions per unit of gross domestic product (GDP) fell by 14 per cent from 1990 to 2004. GHG emissions also grew faster than the Canadian population, resulting in a 10 per cent rise in emissions per person. The freshwater quality indicator presented in this report covered the period from 2002 to 2004, and focused on the ability of Canada's surface waters to support aquatic life. For the 340 sites selected across southern Canada, water quality was rated as good or excellent at 44 per cent of sites, fair at 34 per cent of sites, and marginal or poor at 22 per cent of sites. The report included a chapter which attempted to integrate the indicators with other environmental impacts, measures of economic performance, and indices of social progress to improve the ability of the report to influence decision-making that fully accounts for environmental sustainability. 63 refs., 18 figs

  18. Thinking outside the mainstream; Canadian NGL plants face global competition and decline

    International Nuclear Information System (INIS)

    The nature of the natural gas liquids (NGL) market, and the future prospects of the Canadian NGL industry are discussed. In the short term, demand for NGLs like propane, ethane and condensate is up, the supply picture is good, and the profit margins for Canadian gas plants look positive. At the same time, staying competitive with oil-based naptha and global NGL imports is expected to become more difficult, and the longer term future is far from being without significant problems. Competition is likely to grow as the Canadian energy industry is increasingly looking to heavy oil and bitumen to meet coming energy demand needs; given that it takes about a thousand cubic feet of natural gas to produce each barrel of oil from the oilsands, serious impact on natural gas availability is inevitable, which in turn will affect the supply of NGLs. To reduce the pressure on natural gas, there is an urgent need to come up with other sources of heavy oil production; various options such as coal, nuclear power and even coal gasification are being investigated, albeit too slowly to arrest the decline of North American conventional gas production that started in 2001. Expert opinion is that the real hope for the NGL industry, as well as for the future of natural gas, is the stranded reserve in the Arctic which, however, is expected to flow soon from the Mackenzie Delta. While Arctic gas is expected to negate the impact of waterborne imports from other countries by the USA, the absence of overseas imports does not alter the fact that North America as a petrochemical manufacturer is no longer as competitive with other countries as it once was. The unpleasant reality is that new petrochemical plants are more likely to be built in the Far East and China, where both the feedstock as well as the labour, are much cheaper. 3 photos

  19. The Canadian National Seismograph Network

    OpenAIRE

    North, R G

    1994-01-01

    The Canadian National Seismograph Network currently consists of 5 very-broadband (VBB) and 15 broadband (BB) stations across Canada, supplemented by 6 short period (SP) stations. When it is completed by the end of 1995, a further 1 VBB, 12 BB and over 40 SP stations will have been added. Data from all sites are telemetered in real time to twin network acquisition, processing and archiving centres in Eastern and Western Canada. All data are continuously archived in SEED format on optical disk ...

  20. REGIONAL CHARACTERISTICS OF CANADIAN ENGLISH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Modern English is an international language inthe world.Besides Great Britain,English is spokenas first language in 39 countries.These countries arelocated in different regions with different naturalfeatures,history development and cultural character-istics.Thus,English used in these different regionscarries its own regional character—forming Englishregional varieties.The main English regional varieties are:BritishEnglish,American English,Canadian English andSouth African English.Canada is a rich country inNorth America with its own characteristics,which of

  1. Fuels for Canadian research reactors

    International Nuclear Information System (INIS)

    This paper includes some statements and remarks concerning the uranium silicide fuels for which there is significant fabrication in AECL, irradiation and defect performance experience; description of two Canadian high flux research reactors which use high enrichment uranium (HEU) and the fuels currently used in these reactors; limited fabrication work done on Al-U alloys to uranium contents as high as 40 wt%. The latter concerns work aimed at AECL fast neutron program. This experience in general terms is applied to the NRX and NRU designs of fuel

  2. Seasonal fluxes and age of particulate organic carbon exported from Arctic catchments impacted by localized permafrost slope disturbances

    International Nuclear Information System (INIS)

    Projected warming is expected to alter the Arctic permafrost regime with potential impacts on hydrological fluxes of particulate organic carbon (POC) and sediment. Previous work has focused on large Arctic basins and revealed the important contribution of old carbon in river POC, but little is known about POC fluxes from smaller coastal watersheds, particularly where widespread postglacial raised marine sediments represent a potential source of old soil carbon that could be mobilized by permafrost disturbance. To evaluate these processes, the characteristics of POC, particulate nitrogen (PN) and suspended sediment transport from paired small coastal Arctic watersheds subject to recent permafrost disturbance were investigated at the Cape Bounty Arctic Watershed Observatory (CBAWO) in the Canadian High Arctic. Approximately 2% of the total suspended sediment load from both watersheds was composed of POC and the majority of the sediment and POC fluxes occurred during the spring snowmelt period. Radiocarbon analysis of POC indicates recent permafrost disturbances deliver substantially older POC to the aquatic system. Localized permafrost slope disturbances have a measurable influence on downstream POC age and dominate (estimated up to 78% of POC) sediment fluxes during summer baseflow. The elevation of disturbances and Holocene emergence data show limited age sensitivity of POC to the location of disturbance and suggest slope failures are likely to deliver carbon with a relatively similar age range to the aquatic system, regardless of landscape location. (paper)

  3. Environmental radioactivity in the Arctic

    International Nuclear Information System (INIS)

    The conference considered several broad themes: (1) assessment of releases from landbased sources and river transport, (2) assessment of dumping of nuclear waste, (3) arctic radioecology, (4) assessment of impacts of nuclear explosions and accidents, (5) nuclear safety and consequences of nuclear accidents in the arctic, and (6) waste management. The presentations demonstrated that current levels of radioactivity in the Arctic are generally low. The two most important sources are global fallout from the nuclear weapons tests of the 1950's and 1960's, and discharges to the sea from reprocessing plants in Western Europe which are transported northward by prevailing currents. The conference was attended by scientists from 17 countries and served as a forum for collection and dissemination of information on the range of themes and described above. It is hoped that this will serve to increase awareness of areas of uncertainty and act as a stimulus to further research

  4. The Canadian Hospital Executive Simulation System (CHESS).

    Science.gov (United States)

    Pink, G H; Knotts, U A; Parrish, L G; Shields, C A

    1991-01-01

    The Canadian Hospital Executive Simulation System (CHESS) is a computer-based management decision-making game designed specifically for Canadian hospital managers. The paper begins with an introduction on the development of business and health services industry-specific simulation games. An overview of CHESS is provided, along with a description of its development and a discussion of its educational benefits. PMID:10109530

  5. Theoretical Analysis of Canadian Lifelong Education Development

    Directory of Open Access Journals (Sweden)

    Mukan Natalia

    2014-12-01

    Full Text Available In the article, the problem of Canadian lifelong education development has been studied. The main objectives of the article are defined as theoretical analysis of scientific and pedagogical literature which highlights different aspects of the research problem; periods of lifelong education development; and determination of lifelong learning role and importance in modern Canadian society.

  6. Rural Canadian Youth Exposed to Physical Violence

    Science.gov (United States)

    Laye, Adele M.; Mykota, David B.

    2014-01-01

    Exposure to physical violence is an unfortunate reality for many Canadian youth as it is associated with numerous negative psychosocial effects. The study aims to assist in understanding resilience in rural Canadian youth exposed to physical violence. This is accomplished by identifying the importance of protective factors, as measured by the…

  7. Looking Back: Tracing Trends in Canadian CALL

    Science.gov (United States)

    Craven, Mary-Louise; Sinyor, Roberta

    2011-01-01

    "CCALLNET" ("The Canadian Computer-Assisted Language Learning Network at the Post-Secondary Level") was a semi-annual newsletter published from 1987 to 2002 that was distributed to colleagues across Canada who taught languages to university students. Its objective was to create a network of Canadian faculty interested in CALL by informing them…

  8. Biological results of the snellius expedition XXII. Octocorallia from the Malay Archipelago (Part II)

    NARCIS (Netherlands)

    Verseveldt, J.

    1966-01-01

    The material dealt with in this second part of "Octocorallia from the Malay Archipelago" comprises mainly specimens belonging to the family Nephtheidae. Most of these nephtheids were obtained during the cruise of the "Willebrord Snellius". In addition to this material I examined some specimens colle

  9. Revision of Homalomena (Araceae-Homalomeneae) in New Guinea, the Bismarck Archipelago and Solomon Islands

    NARCIS (Netherlands)

    Hay, A.

    1999-01-01

    The genus Homalomena Schott is revised for New Guinea, the Bismarck Archipelago and Solomon Islands. 19 species are recognised, of which 10 are new to science. Three are rheophytes. Homalomena novoguineensis Engl., H. klossii Ridl., H. ledermannii Engl. & K. Krause, H. moskowskii Engl. & K. Krause a

  10. Ecological footprint of road traffic on Cres-Lošinj Archipelago

    Directory of Open Access Journals (Sweden)

    Hrvoje Grofelnik

    2010-12-01

    Full Text Available Cres-Lošinj Archipelago is the largest insular traffic unit in Northern Adriatic. The archipelago consists of two large islands, Cres and Lošinj, and 27 smaller islands located among Kvarner, Kvarnerić, Rijeka Bay and open sea. From the point of view of traffic, this area gravitates mostly toward Rijeka traffic node. Traffic development of the islands was determined in the second half of the 20th century with the development of ferry traffic and road traffic on the islands. Today, the Archipelago is characterized by prominent seasonal variations of road traffic intensity due to dominant role of tourism in space valorisation. This research included partial determination of Ecological Footprint of road traffic on the islands on the basis of CO2 emission and capacity of insular surfaces to absorb CO2.The author also created a model for calculating road mileage on the islands and indirectly calculated CO2 emission. The results indicated significant seasonal variations of CO2 emission on the islands, which are closely related to tourist valorisation of space and the number of non-residential vehicles on the islands. The paper also provides the ratio between residential and non-residential vehicles on the island, which influence the emission in accordance with their energy efficiency. The research showed that the capacity of CO2 absorption on Cres-Lošinj Archipelago is approximately 40 times greater than CO2 emission from road traffic during one year.

  11. Evolution of heat transport pathways in the Indonesian Archipelago during last deglaciation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Indonesian Archipelago provides important heat transport pathways of the Western Pacific Warm Pool between the northern Indian Ocean and western equatorial Pacific Ocean, that exert important impacts on global climate change. This study investigated AMS 14C, ?18O, planktonic foraminifer assemblages and sedimentation rates in three piston cores collected in the Indonesian Archipelago. The results indicate that changes in the Indonesian Archipelago heat transport pathways were phase characteristic and in steps during the last deglaciation. In the deglaciation Termination IA, at about 12.5 kaBP, sea level rose rapidly in a short time period, and Makassar and Lombok straits widened suddenly for warm and fresh water from the Pacific to pour into the Java Sea and eastern Indian Ocean. During the Termination IB, about 9.5 kaBP, sea level rose rapidly again, and the South China Sea (SCS) started to connect with the Java Sea. With monsoon actions, a large amount of fresh water from the SCS shelf area flew through the Indonesian Archipelago.

  12. Dispersion of radionuclides potentially released from the Atolls of Mururoa and Fangataufa to neighboring archipelagos

    International Nuclear Information System (INIS)

    This paper presents a compartmental model developed to simulate dispersion of radionuclides released to the ocean from the atolls of Mururoa and Fangataufa on a scale of 3000 x 1700 km (150 deg. to 300 deg. S latitude, 130 deg. to 160 deg. W longitude), including the Tuamotu, Cook, Society, Gambier and Austral archipelagos

  13. Checklist and analysis of completeness of the reef fish fauna of the Revillagigedo Archipelago, Mexico.

    Science.gov (United States)

    Fourriére, Manon; Reyes-Bonilla, Héctor; Ayala-Bocos, Arturo; Ketchum, James A; Chávez-Comparan, Juan Carlos

    2016-01-01

    This paper presents an updated checklist of cartilaginous and bony fishes from the Revillagigedo Archipelago reefs and nearby areas (Tropical Eastern Pacific). To compile this list, we gathered data from field surveys between 1994 and 2015, from an exhaustive literature review, and by consulting museum collections and databases. With these records we estimated the completeness of the local fish inventory using four non-parametric rarefaction methods. We report a total of 389 species in 102 families; 235 of these are reef fish that occur in the Eastern but also in the Central Pacific, and 13 species were identified as endemic to the archipelago. A non-parametric statistical model predicts that the expected number of reef fish present at Revillagigedo should be 244.3 ± 3.2 species, which is 9 species more than the observed richness, and this difference was statistically significant (p = 0.02). That predictive model estimates that about 96% of the total richness of reef fish from the archipelago is known. Comparisons of the completeness of the inventory at Revillagigedo to that reported for the fish fauna of the Eastern Pacific and worldwide, showed that the quality of the sampling effort is remarkably high, in spite of the geographic isolation of the archipelago. PMID:27615683

  14. Arctic Energy Resources: Energy Research

    Science.gov (United States)

    Gryc, George

    1984-04-01

    Arctic Energy Resources is a volume of 26 papers recording the proceedings of the Comite' Arctique International Conference, held at the Veritas Centre, Oslo, Norway, September 22-24, 1982. This was the fourth of a series of meetings on the Arctic organized by the Comite', an organization established in the Principality of Monaco with the active support of H.S.H. Prince Rainer III. The fourth Conference was opened by H.R.H. Crown Prins Harald of Norway, a noble beginning for a noble objective.The North Polar Region has drawn world attention recently because of several large hydrocarbon and other mineral discoveries and because of major political and environmental actions in the North American Arctic. Since 1923 when Naval Petroleum Reserve number 4 (NPR-4) was established, northern Alaska has been considered a major petroleum province. It was first explored systematically with modern techniques from 1943 to 1953. In 1958, Alaska became a state, and both federal and state lands in northern Alaska were available for private exploration. Building on the knowledge base provided by the Pet-4 program and its spinoff research laboratory at Barrow, industry explored the area east of NPR-4 and discovered the largest hydrocarbon accumulation (9.6 bbl crude oil and 26 Tcf (trillion cubic feet) gas) in North America at Prudhoe Bay. Concerns for environmental impacts, including oil spills, led to the passing of the National Environmental Policy Act in 1969. In 1970, over 9 million acres were set aside, now known as the Arctic National Wildlife Range, and in 1971 the Alaska Native Claims Settlement Act was passed by the U.S. Congress. The Arab oil embargo of 1973 heightened the energy crisis and changed the economic basis for further exploration in the Arctic. The convergence of these events dramatically changed the balance of power and the pace of activity in the North American Arctic.

  15. Arctic Risk Management (ARMNet) Network: Linking Risk Management Practitioners and Researchers Across the Arctic Regions of Canada and Alaska To Improve Risk, Emergency and Disaster Preparedness and Mitigation Through Comparative Analysis and Applied Research

    Science.gov (United States)

    Garland, A.

    2015-12-01

    The Arctic Risk Management Network (ARMNet) was conceived as a trans-disciplinary hub to encourage and facilitate greater cooperation, communication and exchange among American and Canadian academics and practitioners actively engaged in the research, management and mitigation of risks, emergencies and disasters in the Arctic regions. Its aim is to assist regional decision-makers through the sharing of applied research and best practices and to support greater inter-operability and bilateral collaboration through improved networking, joint exercises, workshops, teleconferences, radio programs, and virtual communications (eg. webinars). Most importantly, ARMNet is a clearinghouse for all information related to the management of the frequent hazards of Arctic climate and geography in North America, including new and emerging challenges arising from climate change, increased maritime polar traffic and expanding economic development in the region. ARMNet is an outcome of the Arctic Observing Network (AON) for Long Term Observations, Governance, and Management Discussions, www.arcus.org/search-program. The AON goals continue with CRIOS (www.ariesnonprofit.com/ARIESprojects.php) and coastal erosion research (www.ariesnonprofit.com/webinarCoastalErosion.php) led by the North Slope Borough Risk Management Office with assistance from ARIES (Applied Research in Environmental Sciences Nonprofit, Inc.). The constituency for ARMNet will include all northern academics and researchers, Arctic-based corporations, First Responders (FRs), Emergency Management Offices (EMOs) and Risk Management Offices (RMOs), military, Coast Guard, northern police forces, Search and Rescue (SAR) associations, boroughs, territories and communities throughout the Arctic. This presentation will be of interest to all those engaged in Arctic affairs, describe the genesis of ARMNet and present the results of stakeholder meetings and webinars designed to guide the next stages of the Project.

  16. Is Submarine Groundwater Discharge a Gas Hydrate Formation Mechanism on the Circum-Arctic Shelf?

    Science.gov (United States)

    Frederick, J. M.; Buffett, B. A.

    2015-12-01

    Methane hydrate is an ice-like solid that can sequester large quantities of methane gas in marine sediments along most continental margins where thermodynamic conditions permit its formation. Along the circum-Arctic shelf, relict permafrost-associated methane hydrate deposits formed when non-glaciated portions of the shelf experienced subaerial exposure during ocean transgressions. Gas hydrate stability and the permeability of circum-Arctic shelf sediments to gas migration is closely linked with relict submarine permafrost. Heat flow observations on the Alaskan North Slope and Canadian Beaufort Shelf suggest the movement of groundwater offshore, but direct observations of groundwater flow do not exist. Submarine discharge, an offshore flow of fresh, terrestrial groundwater, can affect the temperature and salinity field in shelf sediments, and may be an important factor in submarine permafrost and gas hydrate evolution on the Arctic continental shelf. Submarine groundwater discharge may also enhance the transport of organic matter for methanogenesis within marine sediments. Because it is buoyancy-driven, the velocity field contains regions with a vertical (upward) component as groundwater flows offshore. This combination of factors makes submarine groundwater discharge a potential mechanism controlling permafrost-associated gas hydrate evolution on the Arctic continental shelf. In this study, we quantitatively investigate the feasibility of submarine groundwater discharge as a control on permafrost-associated gas hydrate formation on the Arctic continental shelf, using the Canadian Beaufort Shelf as an example. We have developed a shelf-scale, two-dimensional numerical model based on the finite volume method for two-phase flow of pore fluid and methane gas within Arctic shelf sediments. The model tracks the evolution of the pressure, temperature, salinity, methane gas, methane hydrate, and permafrost fields given imposed boundary conditions, with latent heat of

  17. Investigating the occurrence of persistent organic pollutants (POPs) in the arctic: their atmospheric behaviour and interaction with the seasonal snow pack

    International Nuclear Information System (INIS)

    POPs in the Arctic are the focus of international concern due to their occurrence and accumulation in Arctic food webs. This paper presents an overview of the major pathways into the Arctic and details contemporary studies that have focused on the occurrence and transfer of POPs between the major Arctic compartments, highlighting areas where there is a lack of quantitative information. The behaviour of these chemicals in the Arctic atmosphere is scrutinised with respect to long-term trends and seasonal behaviour. Subtle differences between the PCBs and OC pesticides are demonstrated and related to sources outside of the Arctic as well as environmental processes within the Arctic. Unlike temperate regions, contaminant fate is strongly affected by the presence of snow and ice. A description of the high Arctic snow pack is given and the physical characteristics that determine chemical fate, namely the specific surface area of snow and wind driven ventilation, are discussed. Using a well-characterised fresh snow event observed at Alert (Canadian high Arctic) [Atmos. Environ. 36(2002) 2767] the flux of γ-HCH out of the snow is predicted following snow ageing. Under conditions of wind (10 m/s) it is estimated that ∼75% of the chemical may be re-emitted to the atmosphere within 24 h following snowfall, compared with just ∼5% under conditions of no wind. The implications of this are raised and areas of further research suggested. - The fluxes and fate of POPs in snowpacks are key to their behaviour in polar systems

  18. U.S. Arctic Research Commission

    Science.gov (United States)

    “North to the Future” is a well-known slogan in Alaska. This slogan also expresses the spirit with which the U.S. Arctic Research Commission (ARC) has begun its work.The commission was established as a result of Sen. Murkowski's (R-Alaska) Arctic Research and Policy Act of 1984, and its members were appointed by President Reagan last February (Eos, February 26, 1985, p. 91). The ARC has been directed to develop and recommend an integrated Arctic research policy and to work with the concomitantly established Interagency Arctic Research Policy Committee in the formulation of a comprehensive 5-year Arctic research plan (see Figure 1). The Arctic Research and Policy Act designates the National Science Foundation as the lead agency responsible for implementing the policy with other federal agencies; it further requires the preparation of a single, integrated multiagency budget request for Arctic research.

  19. Arctic Glass: Innovative Consumer Technology in Support of Arctic Research

    Science.gov (United States)

    Ruthkoski, T.

    2015-12-01

    The advancement of cyberinfrastructure on the North Slope of Alaska is drastically limited by location-specific conditions, including: unique geophysical features, remoteness of location, and harsh climate. The associated cost of maintaining this unique cyberinfrastructure also becomes a limiting factor. As a result, field experiments conducted in this region have historically been at a technological disadvantage. The Arctic Glass project explored a variety of scenarios where innovative consumer-grade technology was leveraged as a lightweight, rapidly deployable, sustainable, alternatives to traditional large-scale Arctic cyberinfrastructure installations. Google Glass, cloud computing services, Internet of Things (IoT) microcontrollers, miniature LIDAR, co2 sensors designed for HVAC systems, and portable network kits are several of the components field-tested at the Toolik Field Station as part of this project. Region-specific software was also developed, including a multi featured, voice controlled Google Glass application named "Arctic Glass". Additionally, real-time sensor monitoring and remote control capability was evaluated through the deployment of a small cluster of microcontroller devices. Network robustness was analyzed as the devices delivered streams of abiotic data to a web-based dashboard monitoring service in near real time. The same data was also uploaded synchronously by the devices to Amazon Web Services. A detailed overview of solutions deployed during the 2015 field season, results from experiments utilizing consumer sensors, and potential roles consumer technology could play in support of Arctic science will be discussed.

  20. Enabling Technology for the Exploration of the Arctic Ocean - Multi Channel Seismic Reflection data acquisition

    Science.gov (United States)

    Coakley, B.; Anderson, R.; Chayes, D. N.; Goemmer, S.; Oursler, M.

    2009-12-01

    Great advances in mapping the Arctic Ocean have recently been made through the relatively routine acquisition of multibeam data from icebreakers operating on various cruise. The USCGC Healy, the German icebreaker Polarstern, the Canadian icebreaker Amundsen and the Swedish icebreaker Oden all routinely collect multibeam data, even while in heavy ice pack. This increase in data has substantially improved our knowledge of the form of the Arctic Ocean seafloor. Unfortunately, it is not possible to routinely collect Multi Channel Seismic Reflection (MCS) data while underway in the ice pack. Our inability to simply collect these data restricts how we understand many of the features that segment the basin by depriving us of the historical information that can be obtained by imaging the stratigraphy. Without these data, scientific ocean drilling, the ultimate ground truth for Marine Geology, cannot be done. The technology and expertise to collect MCS must be adapted for the particular circumstances of the Arctic Ocean. While MCS data have been collected in the Arctic Ocean, the procedures have relied on icebreakers towing equipment. Since icebreakers follow the path of least resistance through the pack, data are acquired in locations that are not scientifically optimal and rarely in the relatively straight lines necessary for optimal processing. Towing in the ice pack is also difficult, inefficient and puts this equipment at substantial risk of crushing or loss. While icebreakers are one means to collect these data, it is time to conduct a systematic evaluation of the costs and benefits of different platforms for MCS data acquisition. This evaluation should enable collection of high-quality data set at selected locations to solve scientific problems. Substantial uncertainties exist about the relative capabilities, costs and limitations for acquisition of MCS data from various platforms in the Arctic Ocean. For example; - Is it possible to collect multi-channel seismic

  1. Multi Hazard Assessment: The Azores Archipelagos (PT) case

    Science.gov (United States)

    Aifantopoulou, Dorothea; Boni, Giorgio; Cenci, Luca; Kaskara, Maria; Kontoes, Haris; Papoutsis, Ioannis; Paralikidis, Sideris; Psichogyiou, Christina; Solomos, Stavros; Squicciarino, Giuseppe; Tsouni, Alexia; Xerekakis, Themos

    2016-04-01

    The COPERNICUS EMS Risk & Recovery Mapping (RRM) activity offers services to support efficient design and implementation of mitigation measures and recovery planning based on EO data exploitation. The Azores Archipelagos case was realized in the context of the FWC 259811 Copernicus EMS RRM, and provides potential impact information for a number of natural disasters. The analysis identified population and assets at risk (infrastructures and environment). The risk assessment was based on hazard and vulnerability of structural elements, road network characteristics, etc. Integration of different hazards and risks was accounted in establishing the necessary first response/ first aid infrastructure. EO data (Pleiades and WV-2), were used to establish a detailed background information, common for the assessment of the whole of the risks. A qualitative Flood hazard level was established, through a "Flood Susceptibility Index" that accounts for upstream drainage area and local slope along the drainage network (Manfreda et al. 2014). Indicators, representing different vulnerability typologies, were accounted for. The risk was established through intersecting hazard and vulnerability (risk- specific lookup table). Probabilistic seismic hazards maps (PGA) were obtained by applying the Cornell (1968) methodology as implemented in CRISIS2007 (Ordaz et al. 2007). The approach relied on the identification of potential sources, the assessment of earthquake recurrence and magnitude distribution, the selection of ground motion model, and the mathematical model to calculate seismic hazard. Lava eruption areas and a volcanic activity related coefficient were established through available historical data. Lava flow paths and their convergence were estimated through applying a cellular, automata based, Lava Flow Hazard numerical model (Gestur Leó Gislason, 2013). The Landslide Hazard Index of NGI (Norwegian Geotechnical Institute) for heavy rainfall (100 year extreme monthly rainfall

  2. Impacts of decline harvest of country food on nutrient intake among Inuit in Arctic Canada: impact of climate change and possible adaptation plan

    OpenAIRE

    Rosol, Renata; Powell-Hellyer, Stephanie; Chan, Hing Man

    2016-01-01

    Background. The pervasive food insecurity and the diet transition away from local, nutrient-rich country foods present a public health challenge among Inuit living in the Canadian Arctic. While environmental factors such as climate change decreased the accessibility and availability of many country food species, new species were introduced into regions where they were previously unavailable. An adaptation such as turning to alternate country food species can be a viable solution to substitute...

  3. Canadian ice caps as sources of environmental data

    International Nuclear Information System (INIS)

    Seven surface-to-bedrock ice cores, varying from 129 to 337 m in length, have been recovered from Canadian high Arctic ice caps since 1964. While one (Meighen Island) consists entirely of Holocene ice, the others (Devon and Agassiz ice caps) cover time spans of 100,000 years, similar to those from Greenland. The authors relatively thin ice caps provide simple drilling conditions but give records of various parameters from several holes down a flow line. Comparison of these records continues to provide information on signal-to-noise ratios and ice cap rheology. The major disadvantage of thin ice caps is poor resolution in ice more than 5,000 to 10,000 years old. This is offset, however, by the relative ease of retrieval of significant numbers of pollen grains from all levels in the ice. Thus the authors have been able to use pollen as a paleoenvironmental tool leading, for example, to identification of basal ice layers as Sangamonian in age. Similarly, although annual melting of snow at the surface precludes the possibility of using ice cores for gas analysis, the persistence of variable melt layer concentrations through the Holocene ice has given a continuous melt layer record showing gradual deterioration of summer climate from a warm peak 8,000 to 9,000 years ago, to a cold minimum 200 years ago

  4. Northern exposure : as the ice recedes, Arctic exploration, and technology development, heats up

    International Nuclear Information System (INIS)

    This article discussed the affect that climate change and global warming has had on the Arctic and what it foretells for the oil industry. For a few brief weeks during the summers of 2007 and 2008 ice caps receded to the point that ships could navigate the historically impassable Northwest Passage of the Arctic Ocean. The Arctic Institute of North America estimates that the North Pole will be ice-free in 10 to 15 years, much earlier than originally thought. In response to the possibilities that may open up over the next couple of decades, some oil companies are investing hundreds of millions in a new search, with new technologies at old prospect areas. Service provides are increasing research spending into new exploration, production and transportation solutions suited to harsh Arctic conditions. This article described some of the projects planned at locations off Norway and Russia in which advanced subsea production techniques will be applied, such as remotely operated vehicles and liquefied natural gas (LNG) transportation solutions. An unprecedented level of survey activity will resolve border disputes in prospective areas, resulting in seabed mapping that will provide a better understanding of the region. Petro-Canada's efforts to develop the Hecla and Drake Point gas fields was also discussed. The Canadian Energy Research Institute determined that ship-borne transportation from Melville Island in the Arctic is economically feasible. Vancouver-based Teekay Corporation is developing a floating liquefied natural gas (FLNG) technology capable of producing 1 to 2 million tonnes of LNG annually from fields containing 0.5 to 5 tcf. The unique concept was recently granted concept approval by the American Bureau of Shipping, confirming the design is robust and safe. The company is in discussions with potential producers and could be ready for production within 4 years. 6 figs

  5. SO2 in the Fall in the Arctic: Source Identification Using Sulfur Isotopes

    Science.gov (United States)

    Norman, A. L.; Seguin, A.; Rempillo, O. T.

    2011-12-01

    The Arctic atmosphere, although far from industrial sources, has a large anthropogenic SO2 load. Sulfur dioxide can have other sources including from dimethylsulphide (DMS) oxidation. One way to distinguish between these two types of SO2 is through sulfur isotope apportionment. During the Fall seasons of 2007 and 2008 aerosol sulfate and SO2 were measured at two sites in the Arctic. One site was on board the Canadian Coast Guard Ship, The Amundsen, as it traveled throughout the Arctic and the other site was at Alert, Nunavut, Canada. Sulfur dioxide concentrations at Alert varied between 0.02 and 18 nmol/m3 throughout the study with a median of 0.4 nmol/m3. δ34S values ranged between 0 and +11%. Concentrations and δ34S values aboard the Amundsen were much more diverse with concentrations ranging between 0.09 and 134 nmol/m3 (2007 median = 9.4 nmol/m3; 2008 median = 2.0 nmol/m3) and δ34S values ranging between -15 and +18%. High concentrations of SO2 on board the Amundsen were not directly from the Amundsen itself as there was no correlation with peaks in coincident CO2 measurements. Low concentrations of SO2 may, in a few instances, be associated with DMS oxidation. Negative δ34S values were present for samples collected near the Amundsen Gulf and are consistent with a third source of SO2 in the Arctic. This is likely the local source of SO2 from the Smoking Hills in the North West Territories. Distinguishing between these sources of SO2 in the Arctic and the importance of local verses regional sources will be discussed.

  6. Marine ichthyoplankton data from the Canadian Beaufort Sea Shelf, July and September 1984

    Energy Technology Data Exchange (ETDEWEB)

    Chiperzak, D.B.; Hopky, G.E.; Lawrence, M.J.; Lacho, G.

    1990-02-01

    As part of the Beaufort Shelf Fish Habitat Research Subproject of the Northern Oil and Gas Action Program, ichthyoplankton were collected from 760 {mu}m Wiscosin net and 500 {mu}m neuston net plankton tows in July and September of 1984 along the Canadian Beaufort Sea Shelf. A total of 1408 larval fish representing six families and nine species groups were caught in the 34 plankton tows. Arctic cod (Boreogadus saida) was the most abundant larval fish species caught both in the Wisconsin and neuston tows. Standard length, total length, and wet-weight measurements were made on 1123 larval fish of which 1097 were Arctic cod. The July mean standard length for Arctic cod was 13.4 mm with a standard deviation of 2.7 mm, and a mean weight of 0.015 g with a standard deviation of 0.010 g. In September, Arctic cod mean standard length was 26.3 mm, standard deviation of 3.8 mm, and the mean weight was 0.130 g with a standard deviation of 0.058 g. A total of 126 fish were analyzed for stomach contents of which four were found to be empty. Copepods were the most frequently occurring food item in all four species groups analysed with Calanoida being the most frequently occurring and the most abundant food item for both B. saida and the fourhorn sculpin, Myoxcephalus quadricornis. Nine stomachs, all from B. saida, contained the parasite (Trematoda: Hemiuridae). 10 refs., 2 figs., 25 tabs.

  7. Warmer and wetter winters: characteristics and implications of an extreme weather event in the High Arctic

    International Nuclear Information System (INIS)

    One predicted consequence of global warming is an increased frequency of extreme weather events, such as heat waves, droughts, or heavy rainfalls. In parts of the Arctic, extreme warm spells and heavy rain-on-snow (ROS) events in winter are already more frequent. How these weather events impact snow-pack and permafrost characteristics is rarely documented empirically, and the implications for wildlife and society are hence far from understood. Here we characterize and document the effects of an extreme warm spell and ROS event that occurred in High Arctic Svalbard in January–February 2012, during the polar night. In this normally cold semi-desert environment, we recorded above-zero temperatures (up to 7 °C) across the entire archipelago and record-breaking precipitation, with up to 98 mm rainfall in one day (return period of >500 years prior to this event) and 272 mm over the two-week long warm spell. These precipitation amounts are equivalent to 25 and 70% respectively of the mean annual total precipitation. The extreme event caused significant increase in permafrost temperatures down to at least 5 m depth, induced slush avalanches with resultant damage to infrastructure, and left a significant ground-ice cover (∼5–20 cm thick basal ice). The ground-ice not only affected inhabitants by closing roads and airports as well as reducing mobility and thereby tourism income, but it also led to high starvation-induced mortality in all monitored populations of the wild reindeer by blocking access to the winter food source. Based on empirical-statistical downscaling of global climate models run under the moderate RCP4.5 emission scenario, we predict strong future warming with average mid-winter temperatures even approaching 0 °C, suggesting increased frequency of ROS. This will have far-reaching implications for Arctic ecosystems and societies through the changes in snow-pack and permafrost properties. (letter)

  8. Emerging Canadian QA standards for radiation therapy

    International Nuclear Information System (INIS)

    Full text: Canada operates a publicly funded health care system in which 70% of health care costs are paid by some level of government. Radiotherapy, indeed most cancer management, falls within the publicly funded realm of Canada's health care system. National legislation (the Canada Health Act) guarantees access to cancer services for all Canadians. However, the financial responsibility for these services is borne by the provinces. Most Canadian provinces manage the cancer management problem through central cancer agencies. In the past few decades, these provincial cancer agencies have formed the Canadian Association of Provincial Cancer Agencies (CAPCA). This association has adopted a broad mandate for cancer management in Canada (see www.capca.ca). Included in this mandate is the adoption of standards and guidelines for all aspects of cancer control. The complexity of radiation therapy has long underscored the need for cooperation at the international and national levels in defining programmes and standards. In recent decades formal quality assurance programme recommendations have emerged in the United States, Europe and Great Britain. When defining quality assurance programs, Canadian radiation treatment centres have referenced U.S. and other program standards since they have been available. Recently, under the leadership of the Canadian Association of Provincial Cancer Agencies (CAPCA), Canadian national quality assurance program recommendations are emerging. A CAPCA sponsored project to harmonize Canadian quality assurance processes has resulted in a draft document entitled 'Standards for Quality Assurance at Canadian Radiation Treatment Centres'. This document provides recommendations for the broad framework of radiation therapy quality assurance programs. In addition, detailed work is currently underway regarding equipment quality control procedures. This paper explores the historical and political landscape in which the quality assurance problem has

  9. Interact - Access to the Arctic

    Science.gov (United States)

    Johansson, M.; Callaghan, T. V.

    2013-12-01

    INTERACT is currently a network of 50 terrestrial research stations from all Arctic countries, but is still growing. The network was inaugurated in January 2011 when it received an EU 7th Framework award. INTERACT's main objective is to build capacity for identifying, understanding, predicting and responding to diverse environmental changes throughout the wide environmental and land-use envelopes of the Arctic. Implicit in this objective is the task to build capacity for monitoring, research, education and outreach. INTERACT is increasing access to the Arctic: 20 INTERACT research stations in Europe and Russia are offering Transnational Access and so far, 5600 person-days of access have been granted from the total of 10,000 offered. An INTERACT Station Managers' Forum facilitates a dialogue among station managers on subjects such as best practice in station management and standardised monitoring. The Station Managers' Forum has produced a unique 'one-stop-shop' for information from 45 research stations in an informative and attractive Station Catalogue that is available in hard copy and on the INTERACT web site (www.eu-interact.org). INTERACT also includes three joint research activities that are improving monitoring in remote, harsh environments and are making data capture and dissemination more efficient. Already, new equipment for measuring feedbacks from the land surface to the climate system has been installed at several locations, while best practices for sensor networking have been established. INTERACT networks with most of the high-level Arctic organisations: it includes AMAP and WWF as partners, is endorsed by IASC and CBMP, has signed MoUs with ISAC and the University of the Arctic, is a task within SAON, and contributes to the Cold Region community within GEO/GEOSS. INTERACT welcomes other interactions.

  10. The Canadian National Seismograph Network

    Directory of Open Access Journals (Sweden)

    R. G. North

    1994-06-01

    Full Text Available The Canadian National Seismograph Network currently consists of 5 very-broadband (VBB and 15 broadband (BB stations across Canada, supplemented by 6 short period (SP stations. When it is completed by the end of 1995, a further 1 VBB, 12 BB and over 40 SP stations will have been added. Data from all sites are telemetered in real time to twin network acquisition, processing and archiving centres in Eastern and Western Canada. All data are continuously archived in SEED format on optical disk and access to the most recent three days of data is provided through a mail-based AutoDRM system. Continuous data from the VBB sites are sent to the FDSN Data Management Centre approximately one month after being recorded.

  11. Tritium technology. A Canadian overview

    International Nuclear Information System (INIS)

    An overview of the various tritium research and operational activities in Canada is presented. These activities encompass tritium processing and recovery, tritium interactions with materials, and tritium health and safety. Many of these on-going activities form a sound basis for the tritium use and handling aspects of the ITER project. Tritium management within the CANDU heavy water reactor, associated detritiation facilities, research and development facilities, and commercial industry and improving the understanding of tritium behaviour in humans and the environment remain the focus of a long-standing Canadian interest in tritium. While there have been changes in the application of this knowledge and experience over time, the operating experience and the supporting research and development continue to provide for improved plant and facility operations, an improved understanding of tritium safety issues, and improved products and tools that facilitate tritium management. (author)

  12. Canadian natural gas price debate

    International Nuclear Information System (INIS)

    Sunoco Inc. is a subsidiary of Suncor Energy, one of Canada's largest integrated energy companies having total assets of $2.8 billion. As one of the major energy suppliers in the country, Sunoco Inc has a substantial stake in the emerging trends in the natural gas industry, including the Canadian natural gas price debate. Traditionally, natural gas prices have been determined by the number of pipeline expansions, weather, energy supply and demand, and storage levels. In addition to all these traditional factors which still apply today, the present day natural gas industry also has to deal with deregulation, open competition and the global energy situation, all of which also have an impact on prices. How to face up to these challenges is the subject of this discourse. tabs., figs

  13. THE CANADIAN POLITICAL BUSINESS CYCLE

    Directory of Open Access Journals (Sweden)

    Barbara Libby

    2000-01-01

    Full Text Available This paper will discuss the existence of a Canadian Political Business Cycle (PBC during the period 1946-1989. Logit analysis was used to determine if changes in the unemployment rate, growth of real GNE and the rate of inflation are significantly different in the period before an election than during the rest of the electoral term. It was found that the rate of growth in the unemployment rate declines and the rate of growth of real GNP increases in the four quarters before an election. The behavior of these variables reverses in the period after an election. These findings are consistent with a political business cycle. Policy variables, under a majority government, also behave in a manner associated with a PBC, with the government stimulating the economy approximately two years into its term so that good economic news will occur before it has to call an election. Minority governments tend to simulate the economy immediately after taking office.

  14. Nuclear communications : A Canadian perspective

    International Nuclear Information System (INIS)

    Times have changed since the early days of nuclear energy when it was a symbol of a brave new world, Public information strategies have evolved to meet increasing public concerns, and have shifted from being a largely unfocused attempt at publicity to being more concerned with managing issues and solving problems. This paper describes some of the salient features of the Canadian experience in nuclear communications and examines four key aspects: opinion and attitude research; media relations; coeducation; and advertising. It also addresses the challenge of responding to the allegations and tactics of those who are actively hostile to nuclear energy, and recommends that the principles of Total Quality Management and of organizational effectiveness be applied more thorough and more consistently to the public affairs function

  15. A perspective on Canadian shale gas

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Mike; Davidson, Jim; Mortensen, Paul

    2010-09-15

    In a relatively new development over just the past few years, shale formations are being targeted for natural gas production. Based on initial results, there may be significant potential for shale gas in various regions of Canada, not only in traditional areas of conventional production but also non-traditional areas. However, there is much uncertainty because most Canadian shale gas production is currently in experimental or early developmental stages. Thus, its full potential will not be known for some time. If exploitation proves to be successful, Canadian shale gas may partially offset projected long-term declines in Canadian conventional natural gas production.

  16. Dental fitness classification in the Canadian forces.

    Science.gov (United States)

    Groves, Richard R

    2008-01-01

    The Canadian Forces Dental Services utilizes a dental classification system to identify those military members dentally fit for an overseas deployment where dental resources may be limited. Although the Canadian Forces Dental Services dental classification system is based on NATO standards, it differs slightly from the dental classification systems of other NATO country dental services. Data collected by dental teams on overseas deployments indicate a low rate of emergency dental visits by Canadian Forces members who were screened as dentally fit to deploy. PMID:18277717

  17. Canadian national internal dosimetry performance testing programme

    International Nuclear Information System (INIS)

    This paper describes the design and construction of new Performance Testing programme that was implemented in Canada in 2008. The Canadian Regulator (Canadian Nuclear Safety Commission - CNSC) had determined that their licensees, in addition to the existing In Vivo and In Vitro performance tests, needed to demonstrate their ability in interpreting bioassay results. The program is administered by the Canadian National Calibration Reference Centre for Bioassay and In Vivo Monitoring (NCRC). Currently the NCRC carries out the performance testing for the In Vitro and In Vivo. At time of writing, the first round has not been completed and the pass/fail criteria have not been determined. (author)

  18. CRED SVP Drifting Buoy Argos_ID 29099 Data, Rota in the Marianas Archipelago, 200309-200402 (NODC Accession 0067473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29099 was deployed in the region of Marianas Archipelago to assess ocean currents and sea surface temperature. SVP drifter data files...

  19. CRED SVP Drifting Buoy Argos_ID 52299 Data, Arakane in the Marianas Archipelago, 200509-200607 (NODC Accession 0067473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 52299 was deployed in the region of the Marianas Archipelago to assess ocean currents and sea surface temperature. drifter data files...

  20. Geologic Provinces of the Circum-Arctic, 2008 (north of the Arctic Circle)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile includes arcs and polygons that describe U.S. Geological Survey defined 33 geologic provinces of the Circum-Arctic (north of the Arctic Circle). Each...

  1. Coral reef distribution, status and geomorphology-biodiversity relationship in Kuna Yala (San Blas) archipelago, Caribbean Panama

    OpenAIRE

    Andréfouët, Serge; Guzman, H.M.

    2005-01-01

    Most of the knowledge of the reef geomorphology and benthic communities of Kuna Yala coral reefs (Caribbean Panama) comes from the western side of the archipelago, a few tens of kilometers around Punta San Blas (Porvenir). To bridge the gap between Porvenir and the Colombia-Panama border, we investigated with Landsat images the extent and geomorphological diversity of the entire Kuna Yala to provide geomorphologic maps of the archipelago in 12 classes. In addition to remote sensing data, in s...

  2. Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds

    International Nuclear Information System (INIS)

    Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and is also an increasing concern in the Arctic. We assessed potential contaminants (As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) at a shorebird breeding site in Nunavut, Canada. We compared element levels in soil, invertebrates and shorebird blood to assess evidence for bioconcentration and biomagnification within the Arctic-based food chain. We tested whether elements in blood, feathers and eggs of six shorebird species (Pluvialis squatarola, Calidris alpina, C. fuscicollis, Phalaropus fulicarius, Charadrius semipalmatus, and Arenaria interpres) were related to fitness endpoints: adult body condition, blood-parasite load, egg size, eggshell thickness, nest duration, and hatching success. To facilitate comparison to other sites, we summarise the published data on toxic metals in shorebird blood and egg contents. Element concentrations and invertebrate composition differed strongly among habitats, and habitat use and element concentrations differed among shorebird species. Hg, Se, Cd, Cu, and Zn bioconcentrated from soil to invertebrates, and Hg, Se and Fe biomagnified from invertebrates to shorebird blood. As, Ni, Pb, Co and Mn showed significant biodilution from soil to invertebrates to shorebirds. Soil element levels were within Canadian guidelines, and invertebrate Hg levels were below dietary levels suggested for the protection of wildlife. However, maximum Hg in blood and eggs approached levels associated with toxicological effects and Hg-pollution in other bird species. Parental blood-Hg was negatively related to egg volume, although the relationship varied among species. No other elements approached established toxicological thresholds. In conclusion, whereas we found little evidence that exposure to elements at this site is leading to the declines of the species studied, Hg, as found elsewhere in the Canadian Arctic, is of potential

  3. The Arctic Voice at the UN Climate Negotiations: Interplay Between Arctic & Climate Governance

    OpenAIRE

    Duyck, Sébastien, 1983-

    2015-01-01

    During the past decade, the Arctic has progressively gained the status of a “global barometer” of the implications of climate change. As governments finalize in 2015 the negotiations towards a new climate change agreement and as the priorities of the Arctic Council are shifting towards a stronger focus on climate change, the current year offers a timely opportunity to review the interplay between Arctic policies and the international climate change regime. Indeed, several of the Arctic st...

  4. Recent dynamics of arctic and sub-arctic vegetation

    International Nuclear Information System (INIS)

    We present a focus issue of Environmental Research Letters on the ‘Recent dynamics of arctic and sub-arctic vegetation’. The focus issue includes three perspective articles (Verbyla 2011 Environ. Res. Lett. 6 041003, Williams et al 2011 Environ. Res. Lett. 6 041004, Loranty and Goetz 2012 Environ. Res. Lett. 7 011005) and 22 research articles. The focus issue arose as a result of heightened interest in the response of high-latitude vegetation to natural and anthropogenic changes in climate and disturbance regimes, and the consequences that these vegetation changes might have for northern ecosystems. A special session at the December 2010 American Geophysical Union Meeting on the ‘Greening of the Arctic’ spurred the call for papers. Many of the resulting articles stem from intensive research efforts stimulated by International Polar Year projects and the growing acknowledgment of ongoing climate change impacts in northern terrestrial ecosystems. (synthesis and review)

  5. Paleomagnetism of the Mesozoic Asik Mountain mafic complex in northern Alaska: implications for the tectonic history of the Arctic composite terrane

    Science.gov (United States)

    Lewchuk, Michael T.; Foucher, Jamie; Elmore, R.D.

    2004-01-01

    At least three mutually exclusive hypotheses exist for the origin of the Arctic composite terrane and its Mesozoic location relative to the stable craton of North America. The most widely accepted hypothesis calls for counterclockwise rotation of the Arctic composite terrane as it rifted from the Arctic Archipelago. A second hypothesis calls for no relative movement, and a third places the Arctic composite terrane on the Kula plate as a part of a separate ribbon-shaped microcontinent. All three hypotheses predict unique positions for the Arctic composite terrane with respect to rotation and translation since the middle of the Mesozoic. Paleomagnetic and susceptibility studies were conducted on rocks from 15 sites in the ~160 Ma (K-Ar cooling age) Asik Mountain mafic to ultramafic complex in the western part of the Arctic composite terrane. Coherent data from 11 sites yielded a direction of dec = 255.1°, inc = 82.1° κ = 19.3, α95 = 9.6°, α63 = 5.6°. Contact and fold tests were not possible but the direction differs distinctly from the modern magnetic direction. The anisotropy of magnetic susceptibility revealed a well-developed oblate fabric of variable orientation. The orientation of the fabric was not related to the regional stress regime, so we conclude that the rocks were not deformed and metamorphosed during thrusting, and thus the magnetic remanence direction obtained is most likely primary. The direction yields a pole position at long = 166.8°E, lat = 59.8°N, A95 = 18.4°, A63 = 10.7° that is discordant to the expected 160 Ma reference direction for North America. Counterclockwise rotation of the Arctic composite terrane would yield a perfect fit to the 160 Ma reference pole with an allowance for up to 5° of northward translation. This result, combined with previous paleomagnetic data, makes a convincing argument that the Arctic composite terrane has not remained fixed in its current orientation with respect to North America. However, the data are

  6. Arctic tipping points: governance in turbulent times.

    Science.gov (United States)

    Young, Oran R

    2012-02-01

    Interacting forces of climate change and globalization are transforming the Arctic. Triggered by a non-linear shift in sea ice, this transformation has unleashed mounting interest in opportunities to exploit the region's natural resources as well as growing concern about environmental, economic, and political issues associated with such efforts. This article addresses the implications of this transformation for governance, identifies limitations of existing arrangements, and explores changes needed to meet new demands. It advocates the development of an Arctic regime complex featuring flexibility across issues and adaptability over time along with an enhanced role for the Arctic Council both in conducting policy-relevant assessments and in promoting synergy in interactions among the elements of the emerging Arctic regime complex. The emphasis throughout is on maximizing the fit between the socioecological features of the Arctic and the character of the governance arrangements needed to steer the Arctic toward a sustainable future. PMID:22270707

  7. Strategic metal deposits of the Arctic Zone

    Science.gov (United States)

    Bortnikov, N. S.; Lobanov, K. V.; Volkov, A. V.; Galyamov, A. L.; Vikent'ev, I. V.; Tarasov, N. N.; Distler, V. V.; Lalomov, A. V.; Aristov, V. V.; Murashov, K. Yu.; Chizhova, I. A.; Chefranov, R. M.

    2015-11-01

    Mineral commodities rank high in the economies of Arctic countries, and the status of mineral resources and the dynamics of their development are of great importance. The growing tendency to develop strategic metal resources in the Circumarctic Zone is outlined in a global perspective. The Russian Arctic Zone is the leading purveyor of these metals to domestic and foreign markets. The comparative analysis of tendencies in development of strategic metal resources of the Arctic Zone in Russia and other countries is crucial for the elaboration of trends of geological exploration and research engineering. This paper provides insight into the development of Arctic strategic metal resources in global perspective. It is shown that the mineral resource potential of the Arctic circumpolar metallogenic belt is primarily controlled by large and unique deposits of nonferrous, noble, and rare metals. The prospective types of economic strategic metal deposits in the Russian Arctic Zone are shown.

  8. Latitudinal distribution of the recent Arctic warming

    Energy Technology Data Exchange (ETDEWEB)

    Chylek, Petr [Los Alamos National Laboratory; Lesins, Glen K [DALLHOUSIE UNIV.; Wang, Muyin [UNIV OF WASHINGTON

    2010-12-08

    Increasing Arctic temperature, disappearance of Arctic sea ice, melting of the Greenland ice sheet, sea level rise, increasing strength of Atlantic hurricanes are these impending climate catastrophes supported by observations? Are the recent data really unprecedented during the observational records? Our analysis of Arctic temperature records shows that the Arctic and temperatures in the 1930s and 1940s were almost as high as they are today. We argue that the current warming of the Arctic region is affected more by the multi-decadal climate variability than by an increasing concentration of carbon dioxide. Unfortunately, none of the existing coupled Atmosphere-Ocean General Circulation Models used in the IPCC 2007 cIimate change assessment is able to reproduce neither the observed 20th century Arctic cIimate variability nor the latitudinal distribution of the warming.

  9. Canadian Law Schools: In Search of Excellence.

    Science.gov (United States)

    Trakman, Leon E.

    1980-01-01

    Academically, Canadian education is at the crossroads between formalism and functionalism, with the latter prevailing in recent years. There now arises a demand for a more integrated approach, linking legal theory with legal practice. (MSE)

  10. Canadian used fuel disposal concept review

    International Nuclear Information System (INIS)

    A federal government environmental assessment review of the disposal concept developed under the Canadian Nuclear Fuel Waste Management Program is currently underway. The Canadian concept is, simply stated, the placement of used fuel (or fuel waste) in long-lived containers at a depth between 500 m and 1000 m in plutonic rock of the Canadian Shield. Atomic Energy of Canada Limited submitted an Environmental Impact Statement in 1994 and the public hearing aspect of the concept review is in its final phase. A unique aspect of the Canadian situation is that government has stipulated that site selection can not commence until the concept has been approved. Hence, the safety and acceptability of the concept is being reviewed in the context of a generic site. Some comments and lessons learned to date related to the review process are discussed. (author)

  11. Canadian Business Schools: Going out of Business?

    Science.gov (United States)

    Dobni, Dawn; Dobni, Brooke

    1996-01-01

    Using Porter's five-forces model (potential entrants, suppliers, buyers, rivalry, substitutes) to analyze competition in Canadian university business schools, the authors conclude that schools are becoming increasingly vulnerable to competitive pressures and that strategic reorientation is necessary. (SK)

  12. Canadian media representations of mad cow disease.

    Science.gov (United States)

    Boyd, Amanda D; Jardine, Cynthia G; Driedger, S Michelle

    2009-01-01

    A Canadian case of bovine spongiform encephalopathy (BSE) or "mad cow disease" was confirmed in May, 2003. An in-depth content analysis of newspaper articles was conducted to understand the portrayal of BSE and variant Creutzfeldt-Jakob disease (vCJD) in the Canadian media. Articles in the "first 10 days" following the initial discovery of a cow with BSE in Canada on May 20, 2003, were examined based on the premise that these initial stories provide the major frames that dominate news media reporting of the same issue over time and multiple occurrences. Subsequent confirmed Canadian cases were similarly analyzed to determine if coverage changed in these later media articles. The results include a prominence of economic articles, de-emphasis of health aspects, and anchoring the Canadian outbreak to that of Britain's crisis. The variation in media representations between those in Canada and those documented in Britain are explored in this study. PMID:19697246

  13. Evolution of the Arctic Calanus complex: an Arctic marine avocado?

    OpenAIRE

    Berge, Jørgen; Gabrielsen, Tove M.; Mark A Moline; Renaud, Paul

    2012-01-01

    Before man hunted the large baleen whales to near extinction by the end of the nineteenth century, Arctic ecosystems were strongly influenced by these large predators. Their main prey were zooplankton, among which the calanoid copepod species of the genus Calanus, long considered key elements of polar marine ecosystems, are particularly abundant. These herbivorous zooplankters display a range of adaptations to the highly seasonal environments of the polar oceans, most notably extensive energy...

  14. Arctic whaling : proceedings of the International Symposium Arctic Whaling February 1983

    NARCIS (Netherlands)

    Jacob, H.K. s'; Snoeijing, K

    1984-01-01

    Contents: D.M. Hopkins and Louie Marincovich Jr. Whale Biogeography and the history of the Arctic Basin P.M. Kellt, J.H.W. Karas and L.D. Williams Arctic Climate: Past, Present and Future Torgny E. Vinje On the present state and the future fate of the Arctic sea ice cover P.J.H. van Bree On the biol

  15. Arctic shipping emissions inventories and future scenarios

    OpenAIRE

    J. J. Corbett; D. A. Lack; J. J. Winebrake; Harder, S; J. A. Silberman; Gold, M.

    2010-01-01

    The Arctic is a sensitive region in terms of climate change and a rich natural resource for global economic activity. Arctic shipping is an important contributor to the region's anthropogenic air emissions, including black carbon – a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow. These emissions are projected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. To understa...

  16. Identifying uncertainties in Arctic climate change projections

    OpenAIRE

    Hodson, Daniel L. R.; Keeley, Sarah P. E.; West, Alex; Ridley, Jeff; Hawkins, Ed; Hewitt, Helene T.

    2013-01-01

    Wide ranging climate changes are expected in the Arctic by the end of the 21st century, but projections of the size of these changes vary widely across current global climate models. This variation represents a large source of uncertainty in our understanding of the evolution of Arctic climate. Here we systematically quantify and assess the model uncertainty in Arctic climate changes in two CO2 doubling experiments: a multimodel ensemble (CMIP3) and an ensemble constructed using a single mode...

  17. Arctic cephalopod distributions and their associated predators

    OpenAIRE

    Gardiner, Kathleen; Terry A Dick

    2010-01-01

    Cephalopods are key species of the eastern Arctic marine food web, both as prey and predator. Their presence in the diets of Arctic fish, birds and mammals illustrates their trophic importance. There has been considerable research on cephalopods (primarily Gonatus fabricii) from the north Atlantic and the west side of Greenland, where they are considered a potential fishery and are taken as a by-catch. By contrast, data on the biogeography of Arctic cephalopods are still incomplete. This stud...

  18. Shaping a Sustainability Strategy for the Arctic

    OpenAIRE

    Azcarate, Juan; Balfors, Berit; Destouni, Georgia; Bring, Arvid

    2011-01-01

    The development of the Arctic is shaped by the opportunities and constraints brought by climate change and technological advances. In the Arctic, warmer climate is expected to affect ecosystems, local communities and infrastructure due to a combination of effects like reduced sea ice and glaciers, thawing permafrost and increased frequency of floods. Less ice and new technologies mean openings to exploit natural resources in the Arctic. Fishing, mining, hydrocarbon extraction and vessel trans...

  19. Canadian experience with structured clinical examinations.

    OpenAIRE

    Grand'Maison, P.; Lescop, J; Brailovsky, C. A.

    1993-01-01

    The use of structured clinical examinations to improve the evaluation of medical students and graduates has become significantly more common in the past 25 years. Many Canadian medical educators have contributed to the development of this technique. The Canadian experience is reviewed from the introduction of simulated-standardized patients and objective-structured clinical examinations to more recent developments and the use of such examinations for licensure and certification.

  20. South Asian Canadian experiences of depression

    OpenAIRE

    Grewal, Amarjit

    2010-01-01

    This narrative research study explored the socio-cultural context surrounding depression through semi-structured interviews with six South Asian Canadian participants, who self identified as having experienced depression. The study sought to expand on the knowledge of depression and South Asian Canadians by considering the roles of the family, the community, and the culture in the experiences of depression. Thematic analysis of the participant interviews resulted in five major themes: the exp...