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  • 1. Andin, Caroline
    et al.
    Zdanowicz, Christian M.
    Copland, Luke
    Synoptic variability of extreme snowfall in the St. Elias Mountains,Yukon, Canada2015Conference paper (Refereed)
    Abstract [en]

    Glaciers in the Wrangell and St. Elias Mountains (Alaska and Yukon) are presently experiencing some of thehighest regional wastage rates worldwide. While the effect of regional temperatures on glacier melt rates in thisregion has been investigated, comparatively little is known about how synoptic climate variations, for example inthe position and strength of the Aleutian Low, modulate snow accumulation on these glaciers. Such informationis needed to accurately forecast future wastage rates, glacier-water resource availability, and contributions tosea-level rise. Starting in 2000, automated weather stations (AWS) were established in the central St-EliasMountains (Yukon) at altitudes ranging from 1190 to 5400 m asl, to collect climatological data in support ofglaciological research. These data are the longest continuous year-round observations of surface climate everobtained from this vast glaciated region. Here we present an analysis of snowfall events in the icefields of theSt-Elias Mountains based on a decade-long series of AWS observations of snow accumulation. Specifically,we investigated the synoptic patterns and air mass trajectories associated with the largest snowfall events (> 25cm/12 hours) that occurred between 2002 and 2012. Nearly 80% of these events occurred during the cold season(October-March), and in 74 % of cases the precipitating air masses originated from the North Pacific south of50N. Zonal air mass advection over Alaska, or from the Bering Sea or the Arctic Ocean, was comparativelyrare (20%). Somewhat counter-intuitively, dominant surface winds in the St. Elias Mountains during highsnowfall events were predominantly easterly, probably due to boundary-layer frictional drag and topographicfunneling effects. Composite maps of sea-level pressure and 700 mb winds reveal that intense snowfall eventsbetween 2002 and 2012 were associated with synoptic situations characterized by a split, eastwardly-shifted orlongitudinally-stretched Aleutian Low (AL) having an easternmost node near the Kenai Peninsula, conditionsthat drove a strong southwesterly upper airstream across the Gulf of Alaska towards the coast. Situations with asingle-node, westerly-shifted AL were comparatively rare. The spatial configuration of the synoptic AL pressurepattern appears to play a greater role in determining snowfall amount in the central St. Elias Mountains than dopressure anomalies within the AL. The estimated snowfall gradient from coastal Alaska to the central St. EliasMountains during intense snowfall events averaged +2.0 0.7 mm/km (SWE), while the continental-side gradientfrom the mountains towards the Yukon plateau averaged -3.3 0.9 mm/km (SWE). The findings presented herecan better constrain the climatic interpretation of long proxy records of snow accumulation variations developedfrom glacier cores drilled in the St. Elias Mountains or nearby regions.

  • 2. Beal, Samuel A.
    et al.
    Osterberg, Erich C.
    Zdanowicz, Christian M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Fisher, David A.
    Ice Core Perspective on Mercury Pollution during the Past 600 Years2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 13, p. 7641-7647Article in journal (Refereed)
    Abstract [en]

    Past emissions of the toxic metal mercury (Fig) persist in the global environment yet these emissions remain poorly constrained by existing data. Ice cores are high-resolution archives of atmospheric deposition that may provide crucial insight into past atmospheric Hg levels during recent and historical time. Here we present a record of total Hg (Hg-T) in an ice core from the pristine summit plateau (5340 m asl) of Mount Logan, Yukon, Canada, representing atmospheric deposition from AD 1410 to 1998. The Colonial Period (similar to 1603-1850) and North American "Gold Rush" (1850-1900) represent minor fractions (8% and 14%, respectively) of total anthropogenic Hg deposition in the record, with the majority (78%) occurring during the 20th Century. A period of maximum HgT fluxes from 1940 to 1975 coincides with estimates of enhanced anthropogenic Hg emissions from commercial sources, as well as with industrial emissions of other toxic metals. Rapid declines in HgT fluxes following peaks during the Gold Rush and the mid-20th Century indicate that atmospheric Hg deposition responds quickly to reductions in emissions. Increasing HgT fluxes from 1993 until the youngest samples in 1998 may reflect the resurgence of Hg emissions from unregulated coal burning and small-scale gold mining.

  • 3.
    Beal, Samuel A.
    et al.
    US Army, Cold Reg Res & Engn Lab, Hanover, NH 03755 USA..
    Osterberg, Erich C.
    Dartmouth Coll, Dept Earth Sci, Hanover, NH 03755 USA..
    Zdanowicz, Christian M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Fisher, David A.
    Univ Ottawa, Dept Earth Sci, Ottawa, ON K1N 6N5, Canada..
    Response to Comment on "Ice Core Perspective on Mercury Pollution during the Past 600 Years"2016In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 50, no 2, p. 1068-1069Article in journal (Refereed)
  • 4.
    Beaudoin, Anne
    et al.
    Université Laval, Québec, Canada.
    Pienitz, Reinhard
    Université Laval, Québec, Canada.
    Francus, Pierre
    INRS-ETE, Québec, Canada.
    Zdanowicz, Christian M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    St-Onge, Guillaume
    Université du Québec à Rimouski, Canada.
    Paleoenvironmental reconstructions of Nettilling Lake area (Baffin Island, Nunavut): A multi-proxy analysis2014Conference paper (Refereed)
    Abstract [en]

    The paleoclimate and paleolimnological history of several Arctic regions remains poorly known. This is the casefor the area around Nettilling Lake (Baffin Island, Nunavut), the largest lake of the Canadian Arctic Archipelago.To reconstruct the past environmental history of this area, a highly innovative multi-proxy approach combiningphysical, magnetic, chemical and biological properties preserved in lake sediments was used. One particular goalof this study was to investigate the possible coupling between sedimentation processes observed in the lake andmelt rates of nearby Penny Ice Cap.A 1-m long sediment core was retrieved from a small bay in the northeastern part of Nettilling Lake duringthe summer of 2010. This sampling area was chosen based on the hypothesis that incoming glacial meltwatersfrom Penny Ice Cap would leave a strong climate-modulated signal that would be reflected in the sedimentarysequence. The core was analyzed by both non-destructive (X-radiography (X-ray), microfluorescence-X (-XRF),magnetic susceptibility) and destructive (Loss On Ignition, grain size, water content, thin sections, diatoms)techniques. Radiometric AMS 14C and 210Pb/137Cs age determinations, as well as paleomagnetic measurements,were used to develop the core chronology, yielding an estimated bottom age of approximately 1365 AD.The sedimentation rate (0.15 cm.yr-1) in Nettilling Lake was found to be high compared to other Arctic lakes,due to inputs of highly turbid meltwaters from Penny Ice Cap with high suspended sediment loads. Significantcorrelations were found between geochemical profiles of elements linked to detrital inputs (Si, Ti, K, Ca) and meltrates from Penny Ice Cap since the 19th century. This suggests that variations in detrital elements in NettillingLake sediments might be used as an indirect indicator of regional climate fluctuations (e.g., summer temperatures) that determine glacier melt rates.

  • 5.
    Beaudoin, Anne
    et al.
    Université Laval, Québec, Canada.
    Pienitz, Reinhard
    Université Laval, Québec, Canada.
    Francus, Pierre
    INRS-ETE, Québec, Canada.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    St-Onge, Guillaume
    Université du Québec à Rimouski, Québec, Canada.
    Palaeoenvironmental history of the last six centuries in the Nettilling Lake area (Baffin Island, Canada): A multi-proxy analysis2016In: The Holocene, ISSN 0959-6836, E-ISSN 1477-0911, Vol. 26, no 11, p. 1835-1846Article in journal (Refereed)
    Abstract [en]

    The Baffin Island region in the eastern Canadian Arctic has recently experienced a rapid warming, possibly unprecedented in millennia. To investigate theresponse of freshwater environments to this warming and place it in a secular perspective, we analyzed a 90-cm-long sediment core from Nettilling Lake,the largest lake of the Canadian Arctic Archipelago. The core was taken from a part of the lake basin that receives meltwater and sediment inputs from thenearby Penny Ice Cap. The core time scale, established using 137Cs and palaeomagnetic techniques, spans an estimated 600 years. A multi-proxy approachwas used to document changes in the physical, chemical, and biological properties of the sediments. We found evidence for a relatively warm period (mid/late 15th century to mid/late 16th century) during the early part of the ‘Little Ice Age’ (LIA), characterized by high sedimentation rates and laminations.This was followed by colder, drier, and windier conditions corresponding to the coldest phase of LIA and coinciding with the latest and most extensiveperiod of regional ice cap expansion (early 16th to late 19th centuries). A rapid warming occurred at the beginning of the 20th century. Variations intitanium (Ti) content in the core, a proxy for detrital sediment inputs, showed good agreement with reconstructed secular variations in summer meltrates on Penny Ice Cap between the mid-14th century and the present-day, providing supporting evidence for a climatic–hydrological connection betweenthe ice cap and Nettilling Lake.

  • 6. Cardyn, R.
    et al.
    Clark, I. D.
    Lacelle, D.
    Lauriol, B.
    Zdanowicz, Christian
    Calmels, F.
    Molar gas ratios of air entrapped in ice: A new tool to determine the origin of relict massive ground ice bodies in permafrost2007In: Quaternary Research, Vol. 68, no 2, p. 239-248Article in journal (Refereed)
  • 7.
    Copland, Luke
    et al.
    University of Ottawa, Canada.
    Schaffer, Nicole
    University of Ottawa, Canada .
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Nilsson, Johan
    Jet Propulsion Laboratory, CALTECH, USA.
    Ligtenberg, Stefan
    Universiteit Utrecht, Netherlands.
    Gray, Laurence
    University of Ottawa, Canada.
    Surface Elevation Changes Over the Past Decade Across Penny Ice Cap, Baffin Island, Canada2016Conference paper (Other academic)
    Abstract [en]

    Geodetic methods have been relied on heavily to quantify the response of glaciers and ice caps to warmingover the past few decades (e.g. Abdalati et al., 2004; Gardner et al., 2011; Gardner et al., 2012). Typicallyin such studies, the observed surface elevation change of a glacier or ice cap over a given time interval is used to directly calculate its mass loss. However, there can be a change elevation due to a change in firndensification rate or ice dynamics without actual mass loss. For example, at the summit of Penny Ice Cap,Baffin Island, the firn density increased due to the formation of infiltration ice layers, resulting in a 6%increase in cumulative ice‐equivalent thickness between 1995 and 2010 (Zdanowicz et al., 2012).To our knowledge no studies have previously measured the vertical component of ice motion (firncompaction and/or ice dynamics) or adjusted geodetic data over an entire ice cap in the Canadian Arctic. Inthis study we use NASA Airborne Topographic Mapper (ATM) laser altimetry data, ICESat data, as well as insitu geodetic and surface mass balance measurements, to determine surface elevation changes over Penny Ice Cap from 2005‐2013, and correct these data to account for the effects of vertical motion due to ice dynamics and firn densification. Our results show that failure to account for vertical ice motion and firn densification would result in an~19% overestimation of mass loss for this ice cap.

  • 8.
    Cosgrove, Christopher
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Zdanowicz, Christian M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Ingvander, Susanne
    Stockholms Universitet.
    Environmental controls on snow water equivalent in two sub-Arctic mountain catchments2013Conference paper (Other academic)
    Abstract [en]

    Spatial variability of seasonal snow depth poses a challenge when estimating snow water equivalent (SWE) from in-situ measurements in mountainous areas. Poor accessibility, complex topographic effects and localized microclimates make extrapolation of in-situ SWE measurements to a basin scale difficult. Remotely-sensed passive microwave SWE products are also inaccurate in complex terrain and/or at the forest-alpine tundra transition zone. To address these caveats, we investigated the relative importance of landscape qualities (altitude, slope, aspect, vegetation) and climate (winter temperatures, precipitation) on SWE distribution in two sub-Arctic mountainous catchments in Hemavan, Sweden, and Wolf Creek, Yukon, Canada. The two catchments are comparable, but have contrasted climate regimes. In-situ SWE measurements were made in March-April 2014 across the forest-tundra ecotone in both catchments. These were supplemented with historical snow-survey data since 2012 in Hemavan, and 1993 in Wolf Creek. Pairwise linear regressions of SWE against different landscape factors indicate that overall, altitude exerts the largest control on SWE at both Hemavan and Wolf Creek, but its effect is lesser within individual vegetation zones. In other respects, the two sites differ. SWE is inversely correlated to surface slope at forested sites in Hemavan (R^2 = 0.57, p = 0.25), but not in Wolf Creek. Slope aspect is positively correlated with SWE at forest-tundra transition sites (R^2 = 0.49, p = 0.12) in Wolf Creek, but not in Hemavan. For alpine tundra sites, slope angle strongly influences SWE in Hemavan (R^2 = 0.58, p = 0.24), but only weakly in Wolf Creek (R^2 = 0.05, p = 0.71). We discuss possible causes of these inter-catchment differences, and also evaluate the effect of inter-annual climate variations on SWE distribution at Wolf Creek using the long-term snow-survey record. Finally, we compare and discuss SWE estimates obtained by three different field measurement methods.

  • 9. Douglas, T. A.
    et al.
    Loseto, L. L.
    MacDonald, R. W.
    Outridge, P.
    Dommergue, A.
    Poulain, A.
    Amyot, M.
    Barkay, T.
    Berg, T.
    Chetelat, J.
    Constant, P.
    Evans, M.
    Ferrari, C.
    Gantner, N.
    Johnson, M. S.
    Kirk, J.
    Kroer, N.
    Larose, C.
    Lean, D.
    Nielsen, T. G.
    Poissant, L.
    Rognerud, S.
    Skov, H.
    SÞrensen, S.
    Wang, F.
    Wilson, S.
    Zdanowicz, Christian M.
    The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review2012In: Environmental Chemistry, Vol. 9, no 4, p. 321-355Article in journal (Refereed)
  • 10.
    Fisher, D. A.
    et al.
    Geological Survey of Canada .
    Koerner, R. M.
    Geological Survey of Canada .
    Zielinski, G. A.
    University of New Hampshire.
    Wake, C. P.
    University of New Hampshire.
    Zdanowicz, Christian
    Geological Survey of Canada.
    Bourgeois, J. C.
    Geological Survey of Canada.
    Mayewski, P. A.
    University of New Hampshire.
    Grummet, N.
    University of New Hampshire.
    The effects of flowline length evolution on chemistry - δ18O profiles from Penny Ice Cap, Baffin Island, Canada2002In: Annals of Glaciology, ISSN 0260-3055, E-ISSN 1727-5644, Vol. 35, no 1, p. 150-156Article in journal (Refereed)
    Abstract [en]

    The isotopic and chemical signatures for ice-age and Holocene ice from Summit, Greenland, and Penny Ice Cap, Baffin Island, Canada, are compared. The usual pattern of low δ180, high Ca2+ and high Cl- is presented in the Summit records, but Penny Ice Cap has lower than present Cl- in its ice-age ice. A simple extension of the Hansson model (Hansson, 1994) is developed and used to simulate these signatures. The low ice­ age Cl- from Penny Ice Cap is explained by having the ice-age ice originating many thou­sands of km inland near the centre of the Laurentide ice sheet and much further from the marine sources. Summit's flowlines all start close to the present site. The Penny Ice Cap early-Holocene δ180's had to be corrected to offset the Laurentide meltwater distortion.The analysis suggests that presently the Summit and Penny Ice Cap marine impurity ori­ ginates about 500 km away, and that presently Penny Ice Cap receives a significant amountoflocal continental impurity.

  • 11. Fisher, D. A.
    et al.
    Wake, C.
    Kreutz, K.
    Yalcin, K.
    Steig, E.
    Mayewski, P.
    Anderson, L.
    Zheng, J.
    Rupper, S.
    Zdanowicz, Christian M.
    Demuth, M.
    Waszkiewicz, M.
    Dahl-Jensen, D.
    Goto-Azuma, K.
    Bourgeois, J. B.
    Koerner, R. M.
    Sekerka, J.
    Osterberg, E.
    Abbott, M. B.
    Finney, B. P.
    Burns, S. J.
    Stable isotope records from Mount Logan, Eclipse ice cores and nearby Jellybean Lake. Water cycle of the North Pacific over 2000 years and over five vertical kilometres: Sudden shifts and tropical connections2004In: Geographie Physique et Quaternaire, Vol. 58, no 2-3, p. 337-352Article in journal (Refereed)
  • 12. Fisher, D.
    et al.
    Dyke, A.
    Koerner, R.
    Bourgeois, J.
    Kinnard, C.
    Zdanowicz, Christian M.
    de Vernal, A.
    Hillaire-Marcel, C.
    Savelle, J.
    Rochon, A.
    Natural variability of Arctic sea ice over the Holocene2006In: Eos, Vol. 87, no 28, p. 273-275Article in journal (Refereed)
  • 13. Fisher, D.
    et al.
    Osterberg, E.
    Dyke, A.
    Dahl-Jensen, D.
    Demuth, M.
    Zdanowicz, Christian M.
    Bourgeois, J.
    Koerner, R. M.
    Mayewski, P.
    Wake, C.
    Kreutz, K.
    Steig, E.
    Zheng, J.
    Yalcin, K.
    Goto-Azuma, K.
    Luckman, B.
    Rupper, S.
    The Mt Logan Holocene-late Wisconsinan isotope record: Tropical Pacific-Yukon connections2008In: Holocene, Vol. 18, no 5, p. 667-677Article in journal (Refereed)
  • 14. Fisher, D.
    et al.
    Zheng, J.
    Burgess, D.
    Zdanowicz, Christian M.
    Kinnard, C.
    Sharp, M.
    Bourgeois, J.
    Recent melt rates of Canadian arctic ice caps are the highest in four millennia2012In: Global and Planetary Change, Vol. 84-85, p. 3-7Article in journal (Refereed)
  • 15. Foy, N.
    et al.
    Copland, L.
    Zdanowicz, Christian M.
    Demuth, M.
    Hopkinson, C.
    Recent volume and area changes of Kaskawulsh Glacier, Yukon, Canada2011In: Journal of Glaciology, Vol. 57, no 203, p. 515-525Article in journal (Refereed)
  • 16. Gamberg, Mary
    et al.
    Chételat, John
    Poulain, Alexandre
    Zdanowicz, Christian M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Zheng, Jiancheng
    Mercury in the Canadian Arctic Terrestrial Environment: An Update2015In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 509-510, p. 28-40Article in journal (Refereed)
    Abstract [en]

    Contaminants in the Canadian Arctic have been studied over the last twenty years under the guidance of the Northern Contaminants Program. This paper provides the current state of knowledge on mercury (Hg) in theCanadian Arctic terrestrial environment. Snow, ice, and soils on land are key reservoirs for atmospheric deposition and can become sources of Hg through the melting of terrestrial ice and snow and via soil erosion. In the Canadian Arctic, new data have been collected for snow and ice that provide more information on the net accumulation and storage of Hg in the cryosphere. Concentrations of total Hg (THg) in terrestrial snow are highly variable but on average, relatively low (less than 5ng/L), and methylmercury (MeHg) levels in terrestrial snow are also generally low (less than 0.1 ng/L). On average, THg concentrations in snow on Canadian Arctic glaciers are muchlower than those reported on terrestrial lowlands or sea ice. Hg in snow may be affected by photochemical exchanges with the atmosphere mediated by marine aerosols and halogens, and by post-depositional redistribution within the snow pack. Regional accumulation rates of THg in Canadian Arctic glaciers varied little during the past century but show evidence of an increasing north-to-south gradient. Temporal trends of THg in glacier cores indicate an abrupt increase inthe early 1990s, possibly due to volcanic emissions, followed by more stable, but relatively elevated levels. Little information is available on Hg concentrations and processes in Arctic soils. Terrestrial Arctic wildlife typically have low levels of THg (less than μg/g dry weight) in their tissues, although caribou(Rangifer tarandus) can have higher Hg because they consume large amounts of lichen.THg concentrations in the Yukon’s Porcupine caribou herd vary among years but there has been no significant increase or decrease over the last two decades.

  • 17. Kinnard, C.
    et al.
    Koerner, R. M.
    Zdanowicz, Christian M.
    Fisher, D. A.
    Zheng, J.
    Sharp, M. J.
    Nicholson, L.
    Lauriol, B.
    Stratigraphic analysis of an ice core from the Prince of Wales Icefield, Ellesmere Island, Arctic Canada, using digital image analysis: High-resolution density, past summer warmth reconstruction, and melt effect on ice core solid conductivity2008In: Journal of Geophysical Research Atmospheres, Vol. 113, no 24Article in journal (Refereed)
  • 18. Kinnard, C.
    et al.
    Zdanowicz, Christian M.
    Fisher, D. A.
    Alt, B.
    McCourt, S.
    Climatic analysis of sea-ice variability in the Canadian Arctic from operational charts, 1980-20042006In: Annals of Glaciology, Vol. 44, p. 391-402Article in journal (Refereed)
  • 19. Kinnard, C.
    et al.
    Zdanowicz, Christian M.
    Fisher, D. A.
    Isaksson, E.
    De Vernal, A.
    Thompson, L. G.
    Reconstructed changes in Arctic sea ice over the past 1,450 years2011In: Nature, Vol. 479, no 7374, p. 509-512Article in journal (Refereed)
  • 20. Kinnard, C.
    et al.
    Zdanowicz, Christian M.
    Fisher, D. A.
    Wake, C. P.
    Calibration of an ice-core glaciochemical (sea-salt) record with sea-ice variability in the Canadian Arctic2006In: Annals of Glaciology, Vol. 44, p. 383-390Article in journal (Refereed)
  • 21. Kinnard, C.
    et al.
    Zdanowicz, Christian M.
    Koerner, R. M.
    Fisher, D. A.
    A changing Arctic seasonal ice zone: Observations from 1870-2003 and possible oceanographic consequences2008In: Geophysical Research Letters, Vol. 35, no 2Article in journal (Refereed)
  • 22.
    Kos, Gregor
    Concordia University, Canada.
    Yi-Fan, Li
    Environment and Climate Change Canada.
    King, Martha
    Environment Canada, Chemicals Sector Directorate.
    Smyth, Shirley-Anne
    Environment Canada, Canada Centre for Inland Waters.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Zheng, Jiancheng
    Geological Survey of Canada.
    Releases of Mercury into Air and Water from Anthropogenic Activities in Canada2016In: Canadian Mercury Science Assessment Report / [ed] Environment and Climate Change Canada, Environment and Climate Change Canada , 2016, p. 48-54Chapter in book (Refereed)
  • 23. Krachler, M.
    et al.
    Zheng, J.
    Koerner, R.
    Zdanowicz, Christian M.
    Fisher, D.
    Shotyk, W.
    Increasing atmospheric antimony contamination in the northern hemisphere: Snow and ice evidence from Devon Island, Arctic Canada2005In: Journal of Environmental Monitoring, Vol. 7, no 12, p. 1169-1176Article in journal (Refereed)
  • 24. Lacelle, D.
    et al.
    Lauriol, B.
    Clark, I. D.
    Cardyn, R.
    Zdanowicz, Christian M.
    Nature and origin of a Pleistocene-age massive ground-ice body exposed in the Chapman Lake moraine complex, central Yukon Territory, Canada2007In: Quaternary Research, Vol. 68, no 2, p. 249-260Article in journal (Refereed)
  • 25. Osterberg, E. C.
    et al.
    Mayewski, P.
    Kreutz, K.
    Fisher, D.
    Handley, M.
    Sneed, S.
    Zdanowicz, Christian M.
    Zheng, J.
    Demuth, M.
    Waskiewicz, M.
    Bourgeois, J.
    Ice core record of rising lead pollution in the North Pacific atmosphere2008In: Geophysical Research Letters, Vol. 35, no 5Article in journal (Refereed)
  • 26.
    Papasodoro, Charles
    et al.
    Université de Sherbrooke, Sherbrooke, Québec, Canada.
    Berthier, Étienne
    3Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, Centre National de la Recherche Scientifique, Toulouse, France.
    Royer, Alain
    1Centre d’Applications et de Recherches en Télédétection, Université de Sherbrooke, Sherbrooke, Québec, Canada.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Langlois, Alexandre
    1Centre d’Applications et de Recherches en Télédétection, Université de Sherbrooke, Sherbrooke, Québec, Canada.
    Area, elevation and mass changes of the two southernmost ice caps of the Canadian Arctic Archipelago between 1952 and 20142015In: The Cryosphere, ISSN 1994-0416, E-ISSN 1994-0424, Vol. 9, p. 1535-1550Article in journal (Refereed)
    Abstract [en]

    Grinnell and Terra Nivea Ice Caps are located onthe southern Baffin Island, Nunavut, in the Canadian Arctic Archipelago. These relatively small ice caps have received little attention compared to the much larger ice masses further north. Their evolution can, however, give valuable information about the impact of the recent Arctic warming at lower latitudes (i.e. ∼62.5◦ N). In this paper, we measure or estimate historical and recent changes of area, elevation and mass of both ice caps using in situ, airborne and spaceborne data sets, including imagery from the Pléiades satellites. The area of Terra Nivea Ice Cap has decreased by 34 % since the late 1950s, while that of Grinnell Ice Cap has decreased by 20 % since 1952. For both ice caps, the areal reduction accelerated at the beginning of the 21st century. The estimated glacier-wide mass balance was−0.37 ± 0.21 m a^−1 water equivalent (w.e.) over Grinnell Ice Cap for the 1952–2014 period, and −0.47 ± 0.16 m a^−1 w.e. over Terra Nivea Ice Cap for the 1958/59–2014 period. Terra Nivea Ice Cap has experienced an accelerated rate of mass loss of −1.77 ± 0.36 m a^−1 w.e. between 2007 and 2014.This rate is 5.9 times as negative when compared to the 1958/59–2007 period (−0.30 ± 0.19 m a^−1 w.e.) and 2 times as negative when compared to the mass balance of other glaciers in the southern parts of Baffin Island over the 2003– 2009 period. A similar acceleration in mass loss is sus-pected for the Grinnell Ice Cap, given the calculated elevation changes and the proximity to Terra Nivea Ice Cap. The recent increase in mass loss rates for these two ice caps is linked to a strong near-surface regional warming and a lengthening of the melt season into the autumn that may beindirectly strengthened by a later freezing of sea ice in the Hudson Strait sector. On a methodological level, our study illustrates the strong potential of Pléiades satellite data to unlock the underexploited archive of old aerial photographs.

  • 27.
    Schaffer, Nicole
    University of Ottawa.
    Zdanowicz, Christian M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Burgess, David
    Geological Survey of Canada.
    Nilsson, Johan
    Jet Propulsion Laboratory, NASA-CalTech.
    Recent elevation changes of Penny Ice Cap, Baffin Island, corrected for ice dynamics and firn densification2016In: Journal of Geophysical Research - Earth Surface, ISSN 2169-9003, E-ISSN 2169-9011Article in journal (Refereed)
    Abstract [en]

    Measurements of ice cap changes are often based on geodetic methods, which calculate glacier-wide mass loss from elevation change over time. However, these measurements typically don’t account for vertical ice motion caused by firn compaction and/or ice dynamics, so the significance of these factors for mass change measurements over an entire ice cap are currently poorly constrained. In this study, we update NASA Airborne Topographic Mapper (ATM) altimetry elevation changes across Penny Ice Cap (Baffin Island, Canada) to assess total changes in ice mass from 2005-2014. Differential GPS measurements and temporal changes in ice core density profiles are used to calculate vertical motion and isolate the ATM altimetry elevation change due to mass loss. Envisat satellite imagery is used to delineate the areas impacted by firn densification. These calculations, the first for a Canadian Arctic ice cap, indicate that failure to properly account for vertical ice motion results in a 19% overestimation of mass loss. The results, when corrected for vertical motion, are largely insensitive to the assumed density in the firn zone (900 or 800 kg m‑3). Overall, there has been a four-fold increase in mass loss from Penny Ice Cap between 2005-2013 (-5.4 ± 1.9 Gt a-1) compared to the mid-1990s (-1.3 ± 0.7 Gt a-1). The relatively rapid upglacier migration of the equilibrium line altitude (ELA) has left large areas of sub-surface firn in the current ablation area, and has far outpaced the dynamic response of the ice cap to the observed mass loss.

  • 28.
    Schaffer, Nicole
    et al.
    Univ Ottawa, Ottawa, Canada; Geol Survey Canada, Ottawa, Canada.
    Copland, Luke
    Univ Ottawa, Ottawa, Canada.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Ice velocity changes on Penny Ice Cap, Baffin Island, since the 1950s2017In: Journal of Glaciology, ISSN 0022-1430, E-ISSN 1727-5652, Vol. 63, no 240, p. 716-730Article in journal (Refereed)
    Abstract [en]

    Predicting the velocity response of glaciers to increased surface melt is a major topic of ongoing research with significant implications for accurate sea level rise forecasting. In this study we use optical and radar satellite imagery as well as comparisons with historical ground measurements to produce a multi-decadal record of ice velocity variations on Penny Ice Cap, Baffin Island. Over the period 1985 to 2011, the six largest outlet glaciers on the ice cap decelerated at an average rate of 21 m a-1 , or 12% per decade. The change was not monotonous, however, as most glaciers accelerated until the 1990s, then decelerated. A comparison of recent imagery with historical velocity measurements on Highway Glacier, on the southern part of Penny Ice Cap,shows that this glacier decelerated by 71% between 1953 and 2009/11, from 57 to 17 m a-1 . The recent slowdown of outlet glaciers has coincided with increases in mass loss, terminus retreat and an inferred reduction in basal sliding. Measured decelerations are greater than the total short term variability measured from both seasonal and interannual fluctuations, and supports the hypothesis that glacier thinning and/or increased meltwater production promotes a long-term reduction in ice motion.

  • 29.
    Schaffer, Nicole
    et al.
    University of Ottawa, Canada.
    Copland, Luke
    University of Ottawa, Canada.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Nilsson, Johan
    Technical University of Denmark.
    Burgess, David
    Geological Survey of Canada, Ottawa, Canada .
    Volume and mass changes over Penny Ice Cap, Baf-fin Island, from 2005-2013 determined from repeat air-borne laser altimetry.2014In: Proceedings of the 2014 IASC Workshop on the dynamics and mass budget of Arctic glaciers / [ed] L. Copland and C.H. Tijm-Reijmer, 2014Conference paper (Other academic)
    Abstract [en]

    Recent observations of accelerated glacier wastage in Greenland and Alaska haveprompted reassessments of mass balance trends and volume changes on Cana-dian Arctic glaciers and ice caps. While long surface mass balance measurementsare available from glaciers and ice caps in the Queen Elizabeth Islands (e.g., WhiteGlacier, Devon Ice Cap, Meighen Ice Cap), no such records exist for Baffin Islandglaciers. In the absence of such data, air- and space-borne measurements canbe used in combination with in situ data to evaluate historical and recent trendsin ice cover changes. Here, we use repeat laser airborne altimetry surveys con-ducted in 2005 and 2013 by NASA to estimate recent volume and mass changesof Penny Ice Cap, the southernmost large ice cap on Baffin Island ( 66N). Thesedata are validated against in-situ surface mass balance measurements from 2013and IceSat derived elevation change from 2003-2009. Once validated, surface el-evation changes along altimetry lines are extrapolated to the entire ice cap usinga digital elevation model (DEM). Changes in areal extent of the ice cap are con-strained using satellite imagery (e.g. Landsat). From these data we estimate thetotal mass wastage of the ice cap and its recent contribution to sea level rise. Thiswork builds on previous surveys for the period 1995-2005 (Abdalati et al.,2004;Gardneret al.,2012).

  • 30. Shotyk, W.
    et al.
    Zheng, J.
    Krachler, M.
    Zdanowicz, Christian M.
    Koerner, R.
    Fisher, D.
    Predominance of industrial Pb in recent snow (1994-2004) and ice (1842-1996) from Devon Island, Arctic Canada2005In: Geophysical Research Letters, Vol. 32, no 21, p. 1-4Article in journal (Refereed)
  • 31. Stern, G. A.
    et al.
    Macdonald, R. W.
    Outridge, P. M.
    Wilson, S.
    Chételat, J.
    Cole, A.
    Hintelmann, H.
    Loseto, L. L.
    Steffen, A.
    Wang, F.
    Zdanowicz, Christian M.
    How does climate change influence arctic mercury?2012In: Science of the Total Environment, Vol. 414, p. 22-42Article in journal (Refereed)
  • 32. St-Jean, M.
    et al.
    Lauriol, B.
    Clark, I. D.
    Lacelle, D.
    Zdanowicz, Christian M.
    Investigation of ice-wedge infilling processes using stable oxygen and hydrogen isotopes, crystallography and occluded gases (O2, N2, Ar)2011In: Permafrost and Periglacial Processes, Vol. 22, no 1, p. 49-64Article in journal (Refereed)
  • 33.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Ice-core based sulfate and mercury deposition trends in the Canadian Arctic2013Conference paper (Other academic)
  • 34.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Investigating the source of aerosols deposited in snow across the Svalbard archipelago in the 2015-16 winter2017Conference paper (Other academic)
    Abstract [en]

    In the spring that followed the winter 2015-16, a coordinated snow survey across Svalbard was organized under the multinational (Community Coordinated Snow Study in Svalbard) C2S3 project. The goals of the survey were to investigate the spatial variability of the seasonal snow cover, including physical, chemical and biological properties, over a wide array of sites at three different altitude levels (Fig. 1) and using standardized protocols. A particular focus of the project was directed at black carbon (BC) deposition in snow, in order to better constrain estimates of its impact on snow albedo.In order to interpret results of this survey, knowledge of the climatology and air transport patterns to the different sampling sites is needed. Such knowledge is essential to determine how239typical or atypical the 2015-16 winter was with respect to snow conditions, and to identify the most probable source regions for aerosols deposited in snow during this period. Accordingly, an analysis was performed of surface climatological conditions and synoptic air flow patterns during the period of interest using atmospheric reanalysis products, satellite imagery, and air back- trajectory modeling. This presentation will report on the results, with special emphasis on those findings most relevant to BC transport and deposition in Svalbard snow.

  • 35.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beckholmen, Ingrid (Contributor)
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Roach, Patrick (Contributor)
    Environmental Management Yukon.
    Poulain, Alexandre (Contributor)
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences. University of Ottawa.
    Martma, Tonu (Contributor)
    Tallinn University of Technology.
    Ryjkov, Andrei (Contributor)
    Environment and Climate Change Canada.
    Dastorr, Ashu (Contributor)
    Environment and Climate Change Canada.
    Snowmelt, glacial and atmospheric sources of mercury in a subarctic mountain lake catchment, Yukon, Canada2017In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533Article in journal (Refereed)
    Abstract [en]

    In montane regions, ongoing and future shrinkage of glacier cover, coupled with a shortening snow cover period, can profoundly alter river hydrology but also lead to the release of airborne contaminants, such as mercury (Hg), deposited and stored in snow and ice. We used field data coupled with hydrological and atmospheric models to estimate and compare the contributions of Hg from snow/glacier melt and from direct atmospheric deposition, to Kusawa Lake, in subarctic Yukon, Canada. The estimated net Hg accumulation rate in supraglacial snow is 0.55 mg m-2 a-1. The modeled net atmospheric flux, including wet+dry deposition, is ~6 times larger, averaging 3.4 mg m-2 a-1, and comparable to the area-averaged meltwater Hg flux into Kusawa Lake (4.5 mg m-2 a-1). The estimated mass of Hg from snow/ice meltwater entering the lake annually is 0.6 kg, while direct atmospheric deposition may contribute a further 0.4 kg, totaling 1.0 kg a-1. Hg levels in cores taken from glaciers in the catchment's headwaters are mostly above expected pre-industrial values, which suggests that some Hg now being released from glaciers is legacy anthropogenic Hg that accumulated in the past ~150 years. Using regional sediment and stream chemistry data, we estimate that the geogenic Hg load in glacial streams that feed Kusawa Lake is much larger than the amount of atmospherically-derived Hg released from melting ice, but most of this geogenic Hg is likely particle-bound, hence not readily bioavailable.

  • 36.
    Zdanowicz, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    The signature of the large 2015-16 winter storms in Svalbard snowpacks2017Conference paper (Other academic)
  • 37.
    Zdanowicz, Christian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Fisher, David
    Osterberg, Erich
    Kreutz, Karl
    Mayewski, Paul
    Wake, Cameron
    Yalcin, Kaplan
    Dahl-Jensen, Dorthe
    Goto-Azuma, Kumiko
    Steig, Eric
    Rupper, Summer
    Froese, Duane
    Kuehn, Stephen
    Ice cores from the St-Elias Mountains, Yukon Territory, Canada: Their significance for the Holocene climate history, volcanism and air pollution trends in the Northwest Pacific region2014In: Arctic, ISSN 0004-0843, E-ISSN 1923-1245, Vol. 67, no S1, p. 35-57Article in journal (Refereed)
    Abstract [en]

    A major achievement in research supported by the Kluane Lake Research Station was the recovery, in 2001–02, of a suite of cores from the icefields of the central St. Elias Mountains, Yukon, by teams of researchers from Canada, the United States, and Japan. This project led to the development of parallel, long (10^3 – 10^4 year) ice-core records of climate and atmospheric change over an altitudinal range of more than 2 km, from the Eclipse Icefield (3017 m) to the ice-covered plateau of Mt. Logan (5340 m). These efforts built on earlier work recovering single ice cores in this region. Comparison of these records has allowed for variations in climate and atmospheric composition to be linked with changes in the vertical structure and dynamics of the North Pacific atmosphere, providing a unique perspective on these changes over the Holocene. Owing to their privileged location, cores from the St. Elias Icefields also contain a remarkably detailed record of aerosols from various sources around or across the North Pacific. In this paper we review major scientific findings from the study of St. Elias Mountain ice cores, focusing on five main themes: (1) The record of stable water isotopes (δ18O, δD), which has unique characteristics that differ from those of Greenland, other Arctic ice cores, and even among sites in the St. Elias; (2) the snow accumulation history; (3) the record of pollen, biomass burning aerosol, and desert dust deposition; (4) the record of long-range air pollutant deposition (sulphate and lead); and (5) the record of paleo-volcanism. Our discussion draws on studies published since 2000, but based on older ice cores from the St. Elias Mountains obtained in 1980 and 1996.

  • 38.
    Zdanowicz, Christian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Karlsson, Pia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Beckholmen, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Roach, P.
    Poulain, A.
    Yumvihoze, E.
    Martma, T.
    Ryjkov, A.
    Dastoor, A.
    Snowmelt, glacial and atmospheric sources of mercury to a subarctic mountain lake catchment, Yukon, Canada2018In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 238, p. 374-393Article in journal (Refereed)
    Abstract [en]

    In montane regions, ongoing and future shrinkage of glacier cover, coupled with a shortening snow cover period, can profoundly alter river hydrology but also lead to the release of long-range contaminants, such as mercury (Hg), deposited and stored in snow and ice. In this study, field data coupled with hydrological and atmospheric models were used to estimate the contributions of atmospherically-deposited Hg released by snow or glacier ice melt, and from direct atmospheric deposition, to Kusawa Lake, in subarctic Yukon, Canada. The estimated net Hg accumulation rate in supraglacial snow obtained from field samples is 0.55 μg m−2 a−1. The direct annual atmospheric Hg flux to Kusawa Lake, obtained from model simulations, and which includes summertime wet deposition, is ∼6 times larger, averaging 3.04 μg m−2 a−1. The estimated mass of Hg from snow/ice meltwater entering the lake annually is 0.6 kg, while direct atmospheric deposition to the lake may contribute a further 0.4 kg, totaling 1.0 kg a−1. Levels of Hg in cores taken from glaciers in the catchment’s headwaters are mostly above expected pre-industrial values, which suggests that some Hg now being released from glaciers is legacy anthropogenic Hg that accumulated in the past 150 years. At present, the delivery of Hg from melting glacial ice is the largest known source to Kusawa Lake, followed by contemporary atmospheric inputs (direct or via runoff). Efforts should be made to quantify other potential sources, such as subglacial meltwater, runoff from wetlands/forest, or melting permafrost, to better constrain the Hg balance in montane lake catchments of this region.

  • 39.
    Zdanowicz, Christian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Krummel, Eva
    Lean, David
    Poulain, Alexandre
    Kinnard, Christophe
    Yumvihoze, Emmanuel
    Chen, JiuBin
    Hintelmann, Holger
    Pre-industrial and recent (1970-2010) atmospheric deposition of sulfate and mercury in snow on southern Baffin Island, Canada2015In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 509-510, p. 104-114Article in journal (Refereed)
    Abstract [en]

    Sulfate (SO4) and mercury (Hg) are airborne pollutants transported to the Arctic where they can affect properties of the atmosphere and the health of marine or terrestrial ecosystems. Detecting trends in Arctic Hg pollutionis challenging because of the short period of direct observations, particularly of actual deposition. Here, we presentan updated proxy record of atmospheric SO4 and a new 40-year record of total Hg (THg) and monomethyl Hg (MeHg) deposition developed from a firn core (P2010) drilled from Penny Ice Cap, Baffin Island, Canada. The updated P2010 record shows stable mean SO4 levels over the past 40 years, which is inconsistent with observations of declining atmospheric SO4 or snow acidity in the Arctic during the same period. A sharp THg enhancement in the P2010 core ca 1991 is tentatively attributed to the fallout from the eruption of the Icelandic volcano Hekla. Although MeHg accumulation on Penny Ice Cap had remained constant since 1970, THg accumulation increased after the 1980s. This increase is not easily explained by changes in snow accumulation, marine aerosol inputs or air mass trajectories; however, a causal link may exist with the declining sea-ice cover conditions in the Baffin Bay sector. The ratio of THg accumulation between pre-industrial times (reconstructed from archived ice cores) and the modern industrial era is estimated at between 4- and 16-fold, which is consistent with estimates from Arctic lake sediment cores. The new P2010 THg record is the first of its kind developed from the Baffin Island region of the eastern Canadian Arctic and one of very few such records presently available in the Arctic. As such, it may help to bridge the knowledge gap linking direct observation of gaseous Hg in theArctic atmosphere and actual net deposition and accumulation in various terrestrial media.

  • 40.
    Zdanowicz, Christian M.
    et al.
    Geological Survey of Canada.
    Banic, C. M.
    Environment Canada.
    Paktunc, D. A.
    Natural Resources Canada.
    Kliza-Petelle, D. A.
    Geological Survey of Canada.
    Metal emissions from a Cu smelter, Rouyn-Noranda, Quebec: Characterization of particles sampled in air and snow2006In: Geochemistry: Exploration, Environment, Analysis, Vol. 6, no 2-3, p. 147-162Article in journal (Refereed)
    Abstract [en]

    Particles  were  sampled  in  air  and  snow  near  a  Cu  smelter  inRouyn-Noranda, Québec, as part of a study of airborne metal emissions. An analytical scanning electron microscope (SEM) was used to measure the size and elemental composition of >38 000 individual particles. Metal-bearing (Me-) particles account for c. 58% of all particles in the smelter plume, but only c. 15% in ambient air or snow. The dominant Me-particle type in snow is Fe–S–Cu but Zn–S, Fe–S, and Cu–S are also common. Pb is dominant in air-filtered particles, even those collected far (>60 km) from the smelter. Me-particles in snow are compositionally more variable and complex than in the smelter plume or ambient air, suggesting that Me-particles settling from the plume in snow are chemically transformed in the process, possibly by heterogeneous reaction(s) with other aerosols (e.g. salt particles) and/or gases (e.g. SO2). The size distribution of Me-particles in the smelter plume is broader than in snow or ambient air, owing to a larger proportion of sub-micrometre particles in the plume and/or the loss of fine water-soluble Me-particles in snow meltwater. However, the size distribution of different Me-particle groupings (e.g. As-bearing compared to Cd-bearing particles) is notsignificantly different within the size range measured.

  • 41.
    Zdanowicz, Christian M.
    et al.
    Geological Survey of Canada.
    Fisher, D. A.
    Geological Survey of Canada.
    Clark, I.
    University of Ottawa.
    Lacelle, D.
    University of Ottawa.
    An ice-marginal δ18O record from Barnes Ice Cap, Baffin Island, Canada2002In: Annals of Glaciology, ISSN 0260-3055, E-ISSN 1727-5644, Vol. 35, no 1, p. 145-149Article in journal (Refereed)
    Abstract [en]

    Barnes Ice Cap, Baffin Island, Canada, is a remnant of the Laurentide ice sheet that separated from it about 8500 years ago. Owing to recession of the ice cap during the Holocene, Pleistocene-age ice is now exposed along the margin in a distinctive bubble-rich white band. δ180 variations across the white ice resemble those in Canadian Arctic ice cores, suggesting that Barnes Ice Cap preserves a climatic record through thelast glacial period, possibly reaching back into the previous (Sangamon) interglacial. The δ180 shift at the Wisconsin-Holocene transition (15 per mil) exceeds that in other Canadian and Greenland records and cannot be explained solely in climatic terms. A steady-state model reconstruction of the Laurentide ice sheet during the Last Glacial Maximum suggests that Late-glacial strata in Barnes Ice Cap originated high up ( >2400 m a.s.l.) and far "inland" on the ice sheet, along a ridge that extended between the ancestral Foxe and Keewatin ice domes.

  • 42. Zdanowicz, Christian M.
    et al.
    Hall, G.
    Vaive, J.
    Amelin, Y.
    Percival, J.
    Girard, I.
    Biscaye, P.
    Bory, A.
    Asian dustfall in the St. Elias Mountains, Yukon, Canada2006In: Geochimica et Cosmochimica Acta, Vol. 70, no 14, p. 3493-3507Article in journal (Refereed)
  • 43. Zdanowicz, Christian M.
    et al.
    KrÃŒmmel, E. M.
    Lean, D.
    Poulain, A. J.
    Yumvihoze, E.
    Chen, J.
    Hintelmann, H.
    Accumulation, storage and release of atmospheric mercury in a glaciated Arctic catchment, Baffin Island, Canada2013In: Geochimica et Cosmochimica Acta, Vol. 107, p. 316-335Article in journal (Refereed)
  • 44.
    Zdanowicz, Christian M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Krümmel, Eva
    Inuit Circumpolar Council Canada, Ottawa, ON, Canada.
    Poulain, Alexandre
    Univ Ottawa, Dept Biol, Ottawa, ON, Canada.
    Yumvihoze, Emmanuel
    Univ Ottawa, Dept Biol, Ottawa, ON, Canada.
    Chen, JiuBin
    Chinese Acad Sci, State Key Lab Environm Geochem, Guyiang, Peoples R China.
    Štrok, Marco
    Jozef Stefan Inst, Ljubljana, Slovenia.; Trent Univ, Dept Chem, Peterborough, ON, Canada.
    Scheer, Michael
    Scheer Software Solut, Barrys Bay, ON, Canada.
    Hintelmann, Holger
    Trent Univ, Dept Chem, Peterborough, ON, Canada.
    Historical variations of mercury stable isotope ratios in arctic glacier firn and ice cores2016In: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 30, no 9, p. 1324-1347Article in journal (Refereed)
    Abstract [en]

    The concentration and isotopic composition of mercury (Hg) were determined in glacier core samples from Canadian Arctic ice caps dating from pre-industrial to recent time (early 21st century). Mean Hg levels increased from ≤ 0.2 ng L-1 in pre-industrial time to ~0.8-1.2 ng L-1 in the modern industrial era (last ~200 years). Hg accumulated on Arctic ice caps has D199Hg and D201Hg that are higher (~-1 to 2.9 ‰) than previously reported for Arctic snow (mostly < -1 ‰) impacted by atmospheric Hg depletion events, suggesting that these events contribute little to Hg accumulation on ice caps. The range of d202Hg, D199Hg and D201Hg in glacier cores overlaps with that of Arctic Hg0(g) and of seawater in Baffin Bay, but also with that of mid-latitude precipitation and industrial Hg sources, including coal and Hg ores. A core from Agassiz ice cap (80.7 °N) shows a ~+1 ‰ shift in d202Hg over the 19th-20th centuries that could reflect changes in the isotopic composition of the atmospheric Hg pool in the High Arctic in response to growing industrial emissions at lower latitudes. This study is the first ever to report on historical variations of Hg stable isotope ratios in Arctic ice cores. Results could help constrain future modeling efforts of the global Hg biogeochemical cycle and the atmosphere's response to changing Hg emissions, past and future.

  • 45. Zdanowicz, Christian M.
    et al.
    Smetny-Sowa, A.
    Fisher, D.
    Schaffer, N.
    Copland, L.
    Eley, J.
    Dupont, F.
    Summer melt rates on Penny Ice Cap, Baffin Island: Past and recent trends and implications for regional climate2012In: Journal of Geophysical Research: Earth Surface, Vol. 117, no 2Article in journal (Refereed)
  • 46.
    Zdanowicz, Christian M.
    et al.
    Geological Survey of Canada.
    Zielinski, G. A.
    University of New Hampshire.
    Germani, M. S.
    Micromaterials Research Inc..
    Mount Mazama eruption: Calendrical age verified and atmospheric impact assessed1999In: Geology, Vol. 27, no 7, p. 621-624Article in journal (Refereed)
    Abstract [en]

    Geochemical identification of Mount Mazama ash in the Greenland Ice Sheet Project 2(GISP2) ice core gives a calendrical age of 7627 ± 150 cal yr B.P. (5677 ± 150 B.C.) for the erup- tion, thus providing a more accurate early Holocene stratigraphic time line than previously available. The GISP2 record of volcanically derived sulfate suggests a total stratospheric aerosol loading between 88 and 224 Mt spread over an ~6 yr period following the eruption of Mount Mazama. Taking into account the likelihood of some tropospheric aerosol transport to Green- land, realistic estimates of the resulting atmospheric optical depth range from 0.6 to 1.5. These values may have produced a temperature depression of ~0.6 to 0.7 °C at mid to high northern latitudes for 1–3 yr after the eruption. These results indicate that the 5677 B.C. eruption of Mount Mazama was one of the most climatically significant volcanic events of the Holocene in the Northern Hemisphere. We also calculate a maximum stratospheric Cl– release of 8.1 Mt bythe eruption, which may have led to substantial stratospheric ozone depletion.

  • 47.
    Zdanowicz, Christian M.
    et al.
    University of New Hampshire.
    Zielinski, G. A.
    University of New Hampshire.
    Wake, C. P.
    University of New Hampshire.
    Characteristics of modern atmospheric dust deposition in snow on the Penny Ice Cap, Baffin Island, Arctic Canada1998In: Tellus, Series B: Chemical and Physical Meteorology, Vol. 50, no 5, p. 506-520Article in journal (Refereed)
    Abstract [en]

    We evaluated the concentration, size and distribution of insoluble dust microparticles in snow-pits on the Penny Ice Cap (PIC), Ba n Island, to define ( 1) the characteristics of modern atmospheric dust deposition at the site, (2 ) the relative contributions of proximal and distal dust sources, and ( 3) the e ects of summer melting on depositional signals in snow. The mean concentration ( 143 mg kg−1), flux (4.8 mg cm2 yr−1) and diameter (2.3 mm) of dust deposited on the PIC are similar to those observed in remote Arctic sites such as central Greenland, implying that dust is primarily supplied through long-range transport from far-removed source regions (at least 100–1000 km distant). There is evidence for two seasonal maxima of dust deposition, one in late winter-early spring and one in late summer-early fall, although seasonal signals can not always be resolved in the snowpack due to some post-depositional particle migration with summer melt. However, ice layers appear to limit the mobility of particles, thereby preserving valuable paleoclimatic information in the PIC ice core dust record at a multi-annual to decadaltemporal resolution.

  • 48. Zdanowicz, Christian M.
    et al.
    Zielinski, G. A.
    Wake, C. P.
    Fisher, D. A.
    Koerner, R. M.
    A Holocene record of atmospheric dust deposition on the Penny ice cap, Baffin Island, Canada2000In: Quaternary Research, Vol. 53, no 1, p. 62-69Article in journal (Refereed)
  • 49.
    Zdanowicz, Christian
    et al.
    Carleton University, Ottawa, Canada.
    Michel, F. A.
    Carleton University, Ottawa, Canada.
    Shilts, W. W.
    Geologival Survey of Canada.
    Basal debris entrainment and transport in glaciers of southwestern Bylot Island, Canadian Arctic1996In: Annals of Glaciology, ISSN 0260-3055, E-ISSN 1727-5644, Vol. 22, no 1, p. 107-113Article in journal (Refereed)
    Abstract [en]

    ABSTRACT. Glaciers on southwestern Bylot Island in the Canadian Arctic flow from an alpine setting in high-grade crystalline Archean terrane, on to coastal lowlands underlain by clastic sedimentary strata of Cretaceous to Tertiary age.  We have used the contrasting mineralogy of the substrate as a tool to study subglacialentrainment and transport of debris in two large piedmont glaciers on Bylot Island. High chlorite/ and mica-illite/smectite ratios indicate that most basal debris is derived from crystalline rocks underlying the upper reaches of the glaciers. The subglacial accretion of Cretaceous-Tertiary sediments appears restricted to the lowermost part ofthe basal zone and is most noticeable near the glaciers' termini. lce associated with discrete silty-sandy debris layers is characterized by an isotopic signature indicative of refreezing of meltwater at the glacier sole. The compositional, textural and isotopic characteristics of basal sediment and ice lead us to conclude that subglacial entrainment through basal ice accretion occurs in both the upper and marginal parts of the glaciers

  • 50.
    Zdanowicz, Christian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Proemse, Bernadette
    University of Tasmania.
    Edwards, Ross
    Curtin University of Technology, Australia.
    Freiteng, Wang
    Chinese Academy of Sciences.
    Hogan, Chad
    University of Tasmania.
    Kinnard, Christophe
    Université du Québec à Trois-Rivières.
    Fisher, David
    University of Ottawa.
    Historical black carbon deposition in the Canadian High Arctic: A >250-year long ice-core record from Devon Island2018In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 18, p. 1-17Article in journal (Refereed)
    Abstract [en]

    Black carbon aerosol (BC) emitted from natural and anthropogenic sources (e.g., wildfires, coal burning) can contribute to magnify climate warming at high latitudes by darkening snow- and ice-covered surfaces, thus lowering their albedo. Modeling the atmospheric transport and deposition of BC to the Arctic is therefore important, and historical archives of BC accumulation in polar ice can help to validate such modeling efforts. Here we present a 190-year ice-core record of refractory BC (rBC) deposition on Devon ice cap, Canada, spanning calendar years 1810-1990, the first such record ever developed from the Canadian Arctic. The estimated mean deposition flux of rBC on Devon ice cap for 1963-1990 is 0.2 mg m-2 a-1, which is low compared to most Greenland ice-core sites over the same period. The Devon ice cap rBC record also differs from existing Greenland records in that it shows no evidence of a substantial increase in rBC deposition during the early-mid 20th century, which, for Greenland, has been attributed to mid-latitude coal burning emissions. The deposition of other contaminants such as sulfate and Pb increased on Devon ice cap in the 20th century but without a concomitant rise in rBC. Part of the difference with Greenland may be due to local factors such as wind scouring of winter snow at the coring site on Devon ice cap. Air back-trajectory analyses also suggest that Devon ice cap receives BC from more distant North American and Eurasian sources than Greenland, and aerosol mixing and removal during long-range transport over the Arctic Ocean likely masks some of the specific BC source-receptor relationships. Findings from this study underscore the large variability in BC aerosol deposition across the Arctic region that may arise from different transport patterns. This variability needs to be accounted for when estimating the large-scale albedo lowering effect of BC deposition on Arctic snow/ice.

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