Canadian International Polar Year Research Articles

Elevated sources of cobalt in the Arctic Ocean

Abstract. Cobalt (Co) is an important bioactive trace metal that is the metal cofactor in cobalamin (vitamin B12) which can limit or co-limit phytoplankton growth in many regions of the ocean. Total dissolved and labile Co measurements in the Canadian sector of the Arctic Ocean during the U.S. GEOTRACES Arctic expedition (GN01) and the Canadian International Polar Year GEOTRACES expedition (GIPY14) revealed a dynamic biogeochemical cycle for Co in this basin. The major sources of Co in the Arctic were from shelf regions and rivers, with only minimal contributions from other freshwater sources (sea ice, snow) and eolian deposition. The most striking feature was the extremely high concentrations of dissolved Co in the upper 100 m, with concentrations routinely exceeding 800 pmol L−1 over the shelf regions. This plume of high Co persisted throughout the Arctic basin and extended to the North Pole, where sources of Co shifted from primarily shelf-derived to riverine, as freshwater from Arctic rivers was entrained in the Transpolar Drift. Dissolved Co was also strongly organically complexed in the Arctic, ranging from 70 % to 100 % complexed in the surface and deep ocean, respectively. Deep-water concentrations of dissolved Co were remarkably consistent throughout the basin (∼55 pmol L−1), with concentrations reflecting those of deep Atlantic water and deep-ocean scavenging of dissolved Co. A biogeochemical model of Co cycling was used to support the hypothesis that the majority of the high surface Co in the Arctic was emanating from the shelf. The model showed that the high concentrations of Co observed were due to the large shelf area of the Arctic, as well as to dampened scavenging of Co by manganese-oxidizing (Mn-oxidizing) bacteria due to the lower temperatures. The majority of this scavenging appears to have occurred in the upper 200 m, with minimal additional scavenging below this depth. Evidence suggests that both dissolved Co (dCo) and labile Co (LCo) are increasing over time on the Arctic shelf, and these limited temporal results are consistent with other tracers in the Arctic. These elevated surface concentrations of Co likely lead to a net flux of Co out of the Arctic, with implications for downstream biological uptake of Co in the North Atlantic and elevated Co in North Atlantic Deep Water. Understanding the current distributions of Co in the Arctic will be important for constraining changes to Co inputs resulting from regional intensification of freshwater fluxes from ice and permafrost melt in response to ongoing climate change.

High protein and cholesterol intakes associated with emergence of glucose intolerance in a low-risk Canadian Inuit population.

The rate of type 2 diabetes mellitus among Inuit is 12·2 % in individuals over 50 years of age, similar to the Canadian prevalence. Given marked dietary transitions in the Arctic, we evaluated the dietary and other correlates of not previously diagnosed glucose intolerance, defined as type 2 diabetes mellitus, impaired fasting glucose or impaired glucose tolerance. Cross-sectional analyses were limited to adults with a completed 2 h oral glucose tolerance test and without pre-existing diabetes. Anthropometric assessments, health and medication usage questionnaires and a 24 h dietary recall were administered. Canadian International Polar Year Inuit Health Survey (2007-2008). Inuit adults (n 777). Glucose intolerance was associated with older age and adiposity. Percentage of energy from protein above the Acceptable Macronutrient Distribution Range of 35 %, compared with intake within the range, was associated with increased odds of glucose intolerance (OR=1·98; 95 % CI 1·09, 3·61) in multivariable analyses. Further, cholesterol intake in the highest three quartiles combined (median exposures of 207, 416 and 778 mg/d, respectively) compared with the lowest quartile (median intake of 81 mg/d) was associated with glucose intolerance (OR=2·15; 95 % CI 1·23, 3·78) in multivariable analyses. Past-day traditional food consumption was borderline protective of glucose intolerance (P=0·054) and high fibre intake was not significantly protective (P=0·08). The results contribute to the existing literature on high protein and cholesterol intakes as they may relate to diabetes risk.

Assessing the ‘usability’ of climate change research for decision-making: A case study of the Canadian International Polar Year

The creation of ‘usable science’ is widely promoted by many environmental change focused research programs. Few studies however, have examined the relationship between research conducted as part of such programs and the decision-making outcomes that the work is supposed to advance, and is constrained by limited methodological development on how to empirically assess the ‘usability’ of science. Herein, this paper develops a conceptual model and assessment rubric to quantitatively and systematically evaluate the usability of climate change research for informing decision-making. We focus on the process through which data is collected, analyzed and reported and examine the extent to which key principles of usable science are integrated into project design, using grant proposals as our data source. The approach is applied to analyze climate change research conducted as part of the International Polar Year in Canada, with 23 projects identified as having explicit goals to inform decision-making.While the creation of usable science was promoted by funded projects in the International Polar Year, this was not generally reflected in research design: fewer than half determined objectives with input of decision makers, decision context was not widely considered, and knowledge users were not widely reported to be engaged in assessing the quality of data or in resolving conflict in evidence. The importance of science communication was widely emphasized, although only 8/23 projects discussed tailoring specific results for end user needs. Thus while International Polar Year research has made significant advances in understanding the human dimensions of Arctic climate change, key attributes necessary for determining success in linking science to decision-making (pertinence, quality, timeliness) were not captured by many projects. Integrating these attributes into research design from the outset is essential for creating usable science, and needs to be at the forefront of future research programs which aim to advance societal outcomes. The framework for assessing usability here, while developed and tested in an Arctic climate change context, has broader applicability in the general environmental change field.

Annual cycle of air‐sea CO2 exchange in an Arctic Polynya Region

During the Canadian International Polar Year projects in the Cape Bathurst polynya region, we measured a near–complete annual cycle of sea surface CO2 (pCO2sw), atmospheric CO2 (pCO2atm), sea surface temperature (SST), salinity (S), and wind speed (U). In this paper, we combine these data with ancillary measurements of sea ice concentration (Ci) to estimate the mean annual (September 2007–September 2008) air–sea CO2 exchange for the region. For the non–freezing seasons the exchange was calculated using a standard bulk aerodynamic approach, whereas during the freezing seasons we extrapolated eddy covariance measurements of CO2 exchange. Our results show that in 2007–08 the region served as a net sink of atmospheric CO2 at a mean rate of ‐10.1 ± 6.5 mmol m− 2 d− 1. The strongest calculated uptake rate occurred in the fall when wind velocities were highest, pCO2sw was significantly lower than pCO2atm, and ice was beginning to form. Atmospheric CO2 uptake was calculated to occur (at lower rates) throughout the rest of the year, except for a brief period of outgassing during late July. Using archival U, Ci, and pCO2sw data for the region, we found that winds in 2007–08 were 25–35 % stronger than the decadal mean and were predominately easterly, which appears to have induced a relatively late freeze–up (by ∼ 3 weeks relative to mean conditions) and an early polynya opening (by ∼ 4 weeks). In turn, these conditions may have given rise to a higher CO2 uptake than normal. Estimated winter CO2 exchange through leads and small polynya openings made up more than 50% of the total CO2 uptake, consistent with recent observations of enhanced CO2 exchange associated with open water components of the winter icescape. Our calculations for the Cape Bathurst polynya region are consistent with past studies that estimated the total winter CO2 uptake in Arctic coastal polynyas to be on the order of 1012 g C yr− 1.

Canadian International Polar Year (2007–2008): an introduction

Abstract Canadian contributions to International Polar Year (IPY) 2007–2008 were designed to improve the understanding of climate change impacts and adaptation and to gain insight into issues surrounding community health and well-being in Canada’s arctic. Fifty-two research projects, involving scientists, northern partners and communities, focused on the arctic atmosphere and climate, cryosphere, oceans, sea ice, marine ecosystems, terrestrial ecosystems, wildlife as well as human health and community well-being. Key research findings on these topics are presented in this special issue of Climatic Change. This introductory paper presents an overview of the international and Canadian IPY programs and a summary of Canadian IPY results, including progress made in data management and capacity building. The legacy of IPY in Canada includes expanded international scientific cooperation, meaningful partnerships with northern communities, and more northern residents with research training.

Multiple perspectives on polar science educational outreach partnerships in the north Yukon, Canada

A unique element of International Polar Year (IPY) 2007–2008 was the focus on sharing the excitement of ‘doing science’ with northern communities through education and outreach projects. This article reports on the perspectives of key stakeholders in Canadian IPY research projects in their pursuit to incorporate education and outreach in culturally appropriate ways. To identify the benefits, challenges, and common pitfalls when conducting researcher-led science education and outreach activities in the north Yukon, 60 qualitative interviews were conducted with IPY researchers, northern residents, and integrative science educators. Findings suggest that for southern-based research networks working in northern Indigenous communities, educational outreach is most successful in the eyes of northern educators and residents when it is regionally and culturally specific, people-focused, and led by the community's vision and needs.

Consequences of change and variability in sea ice on marine ecosystem and biogeochemical processes during the 2007–2008 Canadian International Polar Year program

Change and variability in the timing and magnitude of sea ice geophysical and thermodynamic state have consequences on many aspects of the arctic marine system. The changes in both the geophysical and thermodynamic state, and in particular the timing of the development of these states, have consequences throughout the marine system. In this paper we review the ‘consequences’ of change in sea ice state on primary productivity, marine mammal habitats, and sea ice as a medium for storage and transport of contaminants and carbon exchange across the ocean-sea-ice-atmosphere interface based upon results from the International Polar Year. Pertinent results include: 1) conditions along ice edges can bring deep nutrient-rich ‘pacific’ waters into nutrient-poor surface waters along the arctic coast, affecting local food webs; 2) both sea ice thermodynamic and dynamic processes ultimately affect ringed seal/polar bear habitats by controlling the timing, location and amount of surface deformation required for ringed seal and polar bear preferred habitat 3) the ice edges bordering open waters of flaw leads are areas of high biological production and are observed to be important beluga habitat. 4) exchange of climate-active gases, including CO2, is extremely active in sea ice environments, and the overall question of whether the Arctic Ocean is (or will be) a source or sink for CO2 will be dependent on the balance of competing climate-change feedbacks.

Change and variability in sea ice during the 2007–2008 Canadian International Polar Year program

In this paper we describe sea ice change and variability during the Canadian International Polar Year (IPY) program and examine several regional and hemispheric causes of this change. In a companion paper (Barber et al., Climate Change2012) we present an overview of the consequences of this observed change and variability on ecosystem function, climatically relevant gas exchange, habitats of primary and apex predators, and impacts on northern peoples. Sea ice-themed research projects within the fourth IPY were designed to be among the most diverse international science programs. They greatly enhanced the exchange of Inuit knowledge and scientific ideas across nations and disciplines. This interdisciplinary and cultural exchange helped to explain and communicate the impacts of a transition of the Arctic Ocean and ecosystem to a seasonally ice-free state, the commensurate replacement of perennial with annual sea ice types and the causes and consequences of this globally significant metamorphosis. This paper presents a synthesis of scientific sea ice research and traditional knowledge results from Canadian-led IPY projects between 2007 and 2009. In particular, a summary of sea ice trends, basin-wide and regional, is presented in conjunction with Inuit knowledge of sea ice, gathered from communities in northern Canada. We focus on the recent observed changes in sea ice and discuss some of the causes of this change including atmospheric and oceanic forcing of both dynamic and thermodynamic forcing on the ice. Pertinent results include: 1) In the Amundsen Gulf, at the western end of the Northwest Passage, open water persists longer than normal and winter sea ice is thinner and more mobile. 2) Large areas of summer sea ice are becoming heavily decayed during summer and can be broken up by long-period waves being generated in the now extensive open water areas of the Chukchi Sea. 3) Cyclones play an important role in flaw leads—regions of open water between pack ice and land-fast ice. They delay the formation of new ice and the growth of multi-year ice. 4) Feedbacks involving the increased period of open water, long-period wave generation, increased open-ocean roughness, and the precipitation of autumn snow are all partially responsible for the observed reduction in multiyear sea ice. 5) The atmosphere is observed as remaining generally stable throughout the winter, preventing vertical entrainment of moisture above the surface.

Design and methods of the Adult Inuit Health Survey 2007–2008

Background. The Canadian International Polar Year (IPY) program made it possible to undertake much needed health research in 3 jurisdictions within the Canadian Inuit Nunangat (homeland) over a 2-year period: Inuvialuit Settlement Region (ISR), Nunavut Territory, and Nunatsiavut.Design. The Adult Inuit Health Survey (IHS) was a cross-sectional survey and provides baseline data upon which future comparisons can be made for prospectively assessing factors leading to the progression of chronic diseases among Canadian Inuit. With the help of the Canadian Coast Guard Ship Amundsen, which was equipped with research and laboratory facilities, 33 coastal communities were visited; land survey teams visited 3 inland communities.Results. The Adult IHS succeeded in obtaining important baseline information concerning the health status and living conditions of 2,595 adults living in ISR, Nunavut and Nunatsiavut.Conclusion. Information from this survey will be useful for future comparisons and the opportunity to link with the International Inuit Cohort, a follow-up evaluation, and for the development of future health policies and public health interventions.

Mesospheric wind diurnal tides within the Canadian Middle Atmosphere Model Data Assimilation System

The horizontal wind data from the standard version of Canadian Middle Atmosphere Model Data Assimilation System (CMAM-DAS) have been analyzed to obtain the diurnal wind structures in the mesosphere. In the standard version of CMAM-DAS, meteorological observations from radiosondes, aircraft, surface measurements, and satellites are assimilated only in the troposphere and stratosphere (below 1-hPa) with no increments applied in the mesosphere. Results for the years 2006–2008 are being used here as part of the Canadian International Polar Year (IPY) program and the Canadian Network for the Detection of Atmospheric Change (CANDAC) Research Program. The CMAM-DAS shows good overall agreement with radar observations for the seasonal characteristics of the diurnal tides at single stations from low-middle latitudes. The most prominent nonmigrating diurnal tides revealed by the CMAM-DAS winds at 88 km include the westward propagating component with zonal wavenumber 2 (DW2), the standing oscillation (D0), and the eastward propagating wavenumbers 3 (DE3) and 2 (DE2). A detailed discussion of the latitudinal and seasonal variations and Hough modes is provided for these predominant nonmigrating components and the migrating tide (DW1). The modeled nonmigrating diurnal tides, on both monthly (60-day windows) and annual time scales, are generally in good agreement with those determined from TIDI (TIMED Doppler interferometer) and from UARS-HRDI (High Resolution Doppler Imager)/WINDII (Wind Imaging Interferometer). This work provides further evidence for the tidal forcing from below.

Linear mixed modelling of snow distribution in the central Yukon

AbstractRemote sensing estimates of snow water equivalent (SWE) in mountainous areas are subject to large uncertainties. As a prerequisite for testing passive microwave algorithm estimations of SWE, this study aims to collect snow depth (SD) data and provide an understanding of its complex spatial structure as part of the Canadian International Polar Year observations theme. Snow accumulation, redistribution and ablation are controlled by processes that depend on a variety of topographic factors as well as land surface characteristics, which leads us to modelling SD as a function of proxy variables derived from digital elevation model and Landsat data. Field measurements were performed at 3924 locations compromising 184 sites in 50 transects over 2 years. These measurements were used to predict SD over the study area using a spatial linear mixed‐effects model, a model type capable of handling the hierarchical structure of the field data.The model, built using stepwise variable selection, uses as predictor variables transformed elevation, slope, the logarithm of slope, potential incoming solar radiation and its transform; the normalized difference vegetation index, and a transformed tasseled cap brightness from Landsat imagery. A second, simpler model links SD with density giving SWE. The cross‐validated root mean squared error of the SD distribution model was 14 cm around an overall mean of 80 cm over a domain of 250 × 250 km.This instantaneous end‐of‐season peak‐accumulation snow map will enable the validation of satellite remote sensing over a generally inaccessible area. Copyright © 2011 John Wiley & Sons, Ltd.

Thank you for the voyage

Along with the darkening days, we can be pleased with yet another year of significantcircumpolar health research and contributions to our Journal. As a concreteexample, in this issue we are happy to present results from the Canadian InternationalPolar Year (IPY) Inuit Health Survey, which is described by Dr. GraceEgeland in her editorial. In addition, Dr. Alan Parkinson provides insight to past, present and future IPY activities related to human health in his special editorial.

Structures and property distributions in the three oceans surrounding Canada in 2007: A basis for a long‐term ocean climate monitoring strategy

The panarctic region is tightly connected to subarctic regions by through‐flowing Atlantic and Pacific water masses and, as such, local changes in ice cover, ocean properties and ecosystem dynamics cannot be fully understood separately from large‐scale oceanographic structures and advective processes. The Canadian International Polar Year (IPY) project Canada's Three Oceans (C3O) and the related Joint Ocean Ice Study (JOIS) have collected oceanographic data along a transit extending around northern North America to establish an initial, large‐scale baseline against which present and future changes can be gauged. Special focus was given to the shelf and the basin regions of the Canada Basin and the Canadian Arctic Archipelago. We use the first results from physical and geochemical data obtained during the summer of 2007 to discuss linkages between the Arctic and Subarctic domains and trace the cascade of key processes that affect contemporary ocean structure. A review of the literature, combined with these observations, is used to identify early signs of ongoing change throughout the three oceans surrounding northern North America including ocean warming and freshening, sea‐ice melting, increased hypoxia, reduced pH and altered biogeography.

Forty-seven Years of Research on the Devon Island Ice Cap, Arctic Canada

The Devon Island ice cap has been the subject of scientific study for almost half a century, beginning with the first mass balance measurements in 1961. Research on the ice cap was the first to investigate (1) the role of meltwater in seasonal ice-velocity variations on a polythermal Arctic ice cap, (2) the use of air temperature rather than net radiation as a proxy for the energy driving surface melt, and (3) the influence of the changing frequency of specific synoptic weather configurations on glacier melt and mass balance. Other research has included investigations of ice cap geometry, flow dynamics, and mass balance; ice core analyses for records of past climate and contaminant deposition; and studies of changes in ice cap area and volume and their relationship to surface mass balance and ice dynamics. Current research includes ground studies connected to efforts to calibrate and validate the radar altimeter that will be carried by the European Space Agency’s (ESA) CryoSat2 satellite, and a major collaborative Canadian International Polar Year (IPY) project focused on the Belcher Glacier, on the northeast side of the ice cap, that examines hydrodynamics of large tidewater glaciers. This paper summarizes our current knowledge of the Devon Island ice cap and identifies some of the outstanding questions that continue to limit our understanding of climate-ice cap interactions in Arctic regions.

Atmospheric‐electric observations of the potential gradient at Chesterfield, Canada

Summary—Continuous records of the atmospheric potential‐gradient were taken at the Canadian International Polar Year station at Chesterfield, N. W. T., from April to August 1933 inclusive. After excluding all days with snow‐drift, fog, or negative values af the potential gradient, 57 days are classed as undisturbed meteorologically. The mean hourly value of the potential gradient for these days is 68 volts per meter. The mean hourly value for each month is practically constant with the exception of April, which has an unusually low value. Analysis of the diurnal variations shows a predominating 24‐hour wave with its maximum varying from 17.7 hours G. M. T., for April and May to 18.7 hours G. M. T., for June, July and August. The potential gradient is definitely higher for days with wind off Hudson Bay than for days with the wind in other directions.