scholarly journals Does Sea Ice Constrain the Breeding Schedules of High Arctic Northern Fulmars?

The Condor ◽  
2007 ◽  
Vol 109 (4) ◽  
pp. 894-906 ◽  
Author(s):  
Mark L. Mallory ◽  
Mark R. Forbes
Keyword(s):  
Sea Ice ◽  
Behavioral Flexibility ◽  
High Arctic ◽  
Egg Laying ◽  
The Arctic ◽  
Breeding Phenology ◽  
Canadian High Arctic ◽  
Behavioral Adaptations ◽  
Southern Colonies ◽  
Colony Attendance

Abstract The Northern Fulmar (Fulmarus glacialis) is a pelagic seabird that breeds across 25° of latitude, from the boreal to the high Arctic oceanographic zones. We examined the breeding schedule of fulmars in the remote Cape Vera colony in the Canadian high Arctic, a marine region covered by sea ice much of the year, to determine if the timing of breeding and colony attendance patterns of birds differed from the breeding phenology of fulmars in colonies farther south. Cape Vera fulmars arrived at the colony later in the year, spent less time at the colony before egg-laying, and took a significantly longer prelaying exodus from the colony compared to fulmars nesting in more southerly colonies. After egg-laying, however, patterns of colony attendance by fulmars in the high Arctic were similar to patterns for fulmars in southern colonies; this part of the fulmar breeding schedule may be inflexible. The differences in breeding schedules across the species' range might reflect behavioral adaptations by arctic-nesting birds to accommodate the physical and biological limitations imposed by extensive sea ice near arctic colonies, particularly early in the breeding season. Given that climate warming and corresponding reductions in sea ice are taking place in the Arctic, it remains to be determined whether fulmars in the high Arctic have the behavioral flexibility in their breeding phenology to compensate for rapidly occurring changes in their environment.

scholarly journals A trajectory analysis of atmospheric transport of black carbon aerosols to Canadian High Arctic in winter and spring (1990–2005)

2010 ◽  
Vol 10 (2) ◽  
pp. 2221-2244 ◽  
Author(s):  
L. Huang ◽  
S. L. Gong ◽  
S. Sharma ◽  
D. Lavoué ◽  
C. Q. Jia
Keyword(s):  
Regression Model ◽  
Black Carbon ◽  
North American ◽  
Emission Intensity ◽  
Atmospheric Transport ◽  
High Arctic ◽  
The Arctic ◽  
Canadian High Arctic ◽  
Near Surface ◽  
Annual Variations

Abstract. Black carbon (BC) particles accumulated in the Arctic troposphere and deposited over snow have significant effects on radiative forcing of the Arctic regional climate. Applying cluster analysis technique on 10-day backward trajectories, transport pathways affecting Alert (82.5° N, 62.5° W), Nunavut in Canada are identified in this work, along with the associated transport frequency. Based on the atmospheric transport frequency and the estimated BC emission intensity from surrounding regions, 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 measured 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. 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 Eurasia is the major contributor to the near-surface BC levels at the Canadian High Arctic site with an average contribution of over 85% during the 16-year period. In winter, the atmospheric transport of BC aerosols from Eurasia is found to be even more predominant with a multi-year average of 94%. The model estimates smaller contribution from the Eurasian sector in spring (70%) than that in winter. It is also found that the change in Eurasian contributions depends mainly on the reduction of emission intensity, while the changes in both emission and atmospheric transport contributed to the inter-annual variation of North American contributions.

scholarly journals Dynamics of Ice-Island Motion Near the Coast of Axel Heiberg Island, Canadian High Arctic

1989 ◽  
Vol 12 ◽  
pp. 152-156 ◽  
Author(s):  
W.M. Sackinger ◽  
M.O. Jeffries ◽  
H. Tippens ◽  
F. Li ◽  
M. Lu
Keyword(s):  
Surface Wind ◽  
High Arctic ◽  
The Arctic ◽  
Movement Direction ◽  
Canadian High Arctic ◽  
North West ◽  
The North ◽  
Pack Ice ◽  
Axel Heiberg Island ◽  
Ice Force

The largest ice island presently known to exist in the Arctic Ocean has a mass of about 700 × 106 tonnes, an area of about 26 km2, and a mean thickness of 42.5 m. Known as Hobson’s Ice Island, this large ice feature has been tracked almost continuously since August 1983 with a succession of Argos buoys. In this paper, two particular ice-island movement episodes near the north-west coast of Axel Heiberg Island are described: 6–16 May 1986 and 14–21 June 1986. Each movement episode is analyzed in terms of the forces acting on the ice island, including wind shear, water drag, water shear, Coriolis force, sea-surface tilt, and pack-ice force. Ice-island movement is generally preceded by an offshore surface wind, and a threshold wind speed of 6 m s°1 appears to be necessary to initiate ice-island motion. An angle of 50° between surface wind and ice-island movement direction is noted during one episode. The pack-ice force, which appears to be the dominant arresting factor of ice-island motion for these two episodes, varies from 100° to 180° to the left of the ice-island velocity direction, depending upon whether the ice island is accelerating or decelerating.

scholarly journals Influence of the Arctic Circumpolar Vortex on the Mass Balance of Canadian High Arctic Glaciers

2007 ◽  
Vol 20 (18) ◽  
pp. 4586-4598 ◽  
Author(s):  
Alex S. Gardner ◽  
Martin Sharp
Keyword(s):  
Mass Balance ◽  
Regime Shift ◽  
High Arctic ◽  
Western Hemisphere ◽  
The Arctic ◽  
Glacier Mass Balance ◽  
Canadian High Arctic ◽  
Circumpolar Vortex ◽  
Eastern Hemisphere ◽  
Air Temperatures

Abstract Variability in July mean surface air temperatures from 1963 to 2003 accounted for 62% of the variance in the regional annual glacier mass balance signal for the Canadian High Arctic. A regime shift to more negative regional glacier mass balance occurred between 1986 and 1987, and is linked to a coincident shift from lower to higher mean July air temperatures. Both the interannual changes and the regime shifts in regional glacier mass balance and July air temperatures are related to variations in the position and strength of the July circumpolar vortex. In years when the July vortex is “strong” and its center is located in the Western Hemisphere, positive mass balance anomalies prevail. In contrast, highly negative mass balance anomalies occur when the July circumpolar vortex is either weak or strong without elongation over the Canadian High Arctic, and its center is located in the Eastern Hemisphere. The occurrence of westerly positioned July vortices has decreased by 40% since 1987. The associated shift to a dominantly easterly positioned July vortex was associated with an increased frequency of tropospheric ridging over the Canadian High Arctic, higher surface air temperatures, and more negative regional glacier mass balance.

scholarly journals Analysis of reactive bromine production and ozone depletion in the Arctic boundary layer using 3-D simulations with GEM-AQ: inference from synoptic-scale patterns

2011 ◽  
Vol 11 (8) ◽  
pp. 3949-3979 ◽  
Author(s):  
K. Toyota ◽  
J. C. McConnell ◽  
A. Lupu ◽  
L. Neary ◽  
C. A. McLinden ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Sea Ice ◽  
Ozone Depletion ◽  
Surface Ozone ◽  
High Arctic ◽  
Heterogeneous Reactions ◽  
The Arctic ◽  
Synoptic Scale ◽  
Arctic Boundary Layer ◽  
Surface Snow

Abstract. Episodes of high bromine levels and surface ozone depletion in the springtime Arctic are simulated by an online air-quality model, GEM-AQ, with gas-phase and heterogeneous reactions of inorganic bromine species and a simple scheme of air-snowpack chemical interactions implemented for this study. Snowpack on sea ice is assumed to be the only source of bromine to the atmosphere and to be capable of converting relatively stable bromine species to photolabile Br2 via air-snowpack interactions. A set of sensitivity model runs are performed for April 2001 at a horizontal resolution of approximately 100 km×100 km in the Arctic, to provide insights into the effects of temperature and the age (first-year, FY, versus multi-year, MY) of sea ice on the release of reactive bromine to the atmosphere. The model simulations capture much of the temporal variations in surface ozone mixing ratios as observed at stations in the high Arctic and the synoptic-scale evolution of areas with enhanced BrO column amount ("BrO clouds") as estimated from satellite observations. The simulated "BrO clouds" are in modestly better agreement with the satellite measurements when the FY sea ice is assumed to be more efficient at releasing reactive bromine to the atmosphere than on the MY sea ice. Surface ozone data from coastal stations used in this study are not sufficient to evaluate unambiguously the difference between the FY sea ice and the MY sea ice as a source of bromine. The results strongly suggest that reactive bromine is released ubiquitously from the snow on the sea ice during the Arctic spring while the timing and location of the bromine release are largely controlled by meteorological factors. It appears that a rapid advection and an enhanced turbulent diffusion associated with strong boundary-layer winds drive transport and dispersion of ozone to the near-surface air over the sea ice, increasing the oxidation rate of bromide (Br−) in the surface snow. Also, if indeed the surface snowpack does supply most of the reactive bromine in the Arctic boundary layer, it appears to be capable of releasing reactive bromine at temperatures as high as −10 °C, particularly on the sea ice in the central and eastern Arctic Ocean. Dynamically-induced BrO column variability in the lowermost stratosphere appears to interfere with the use of satellite BrO column measurements for interpreting BrO variability in the lower troposphere but probably not to the extent of totally obscuring "BrO clouds" that originate from the surface snow/ice source of bromine in the high Arctic. A budget analysis of the simulated air-surface exchange of bromine compounds suggests that a "bromine explosion" occurs in the interstitial air of the snowpack and/or is accelerated by heterogeneous reactions on the surface of wind-blown snow in ambient air, both of which are not represented explicitly in our simple model but could have been approximated by a parameter adjustment for the yield of Br2 from the trigger.

scholarly journals Little auks under the midnight sun: diel activity rhythm of a small diving seabird during the Arctic summer

2020 ◽  
Author(s):  
Katarzyna Wojczulanis-Jakubas ◽  
Piotr Wąż ◽  
Dariusz Jakubas
Keyword(s):  
Daily Activity ◽  
Activity Rhythm ◽  
Activity Patterns ◽  
Population Level ◽  
High Arctic ◽  
The Arctic ◽  
Diel Activity ◽  
Little Auk ◽  
Individual Level ◽  
Colony Attendance

Many animal species exhibit a diel, 24-hr pattern of activity, which is steered by timing cues, with the daily light–dark cycle considered the most powerful. This cue, however, is reduced in polar zones under continuous daylight conditions associated with the midnight sun. The rhythm of animal behaviour under such conditions is poorly understood. Here, we examine periodicity and patterns of daily activity (colony attendance and foraging) in a High-Arctic seabird, the little auk (Alle alle). We demonstrated a regular rhythm of colony attendance at the population level, with birds being the most abundant in the colony during hours of relatively low sun elevation. This pattern is likely to be associated with predation pressure that may be perceived by birds as lower during hours with low sun elevation, because of better predator detectability. Regarding rhythms at an individual level, however, we found the most common periodicity to be 23.2 hr (range from 19.9 hr to 30.8 hr) but no clear pattern of daily colony attendance of individuals. Such a flexibility in daily rhythms indicates that individuals may become arrhythmic in regard to the 24-hr environmental cycle, despite regularities observed at the population level. Finally, we compared males and females in terms of daily activity patterns but we did not find significant sex differences.

scholarly journals Daily transcriptomes of the copepod Calanus finmarchicus during the summer solstice at high Arctic latitudes

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Laura Payton ◽  
Céline Noirot ◽  
Claire Hoede ◽  
Lukas Hüppe ◽  
Kim Last ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sea Ice ◽  
Marine Ecosystem ◽  
High Arctic ◽  
Trophic Levels ◽  
Calanus Finmarchicus ◽  
The Arctic ◽  
Summer Solstice ◽  
Important Species ◽  
Ice Coverage

AbstractThe zooplankter Calanus finmarchicus is a member of the so-called “Calanus Complex”, a group of copepods that constitutes a key element of the Arctic polar marine ecosystem, providing a crucial link between primary production and higher trophic levels. Climate change induces the shift of C. finmarchicus to higher latitudes with currently unknown impacts on its endogenous timing. Here we generated a daily transcriptome of C. finmarchicus at two high Arctic stations, during the more extreme time of Midnight Sun, the summer solstice. While the southern station (74.5 °N) was sea ice-free, the northern one (82.5 °N) was sea ice-covered. The mRNAs of the 42 samples have been sequenced with an average of 126 ± 5 million reads (mean ± SE) per sample, and aligned to the reference transcriptome. We detail the quality assessment of the datasets and the complete annotation procedure, providing the possibility to investigate daily gene expression of this ecologically important species at high Arctic latitudes, and to compare gene expression according to latitude and sea ice-coverage.

Arctic Security, Territory, Population: Canadian Sovereignty and the International

2019 ◽  
Vol 13 (4) ◽  
pp. 358-374
Author(s):  
Mark B Salter
Keyword(s):  
Canadian Arctic ◽  
High Arctic ◽  
The Arctic ◽  
Canadian High Arctic ◽  
Territorial Sovereignty ◽  
Arctic Security ◽  
Simultaneous Implementation ◽  
Blind Spots

Abstract Canada's policies to assert and maintain sovereignty over the High Arctic illuminate both the analytical leverage and blind spots of Foucault's influential Security, Territory, Population (2007) schema for understanding modern governmentality. Governmental logics of security, sovereignty, and biopolitics are contemporaneous and concomitant. The Arctic case demonstrates clearly that the Canadian state messily uses whatever governmental tools are in its grasp to manage the Inuit and claim territorial sovereignty over the High North. But, the case of Canadian High Arctic policies also illustrates the limitations of Foucault's schema. First, the Security, Territory, Population framework has no theorization of the international. In this article I show the simultaneous implementation of Canadian security-, territorial-, and population-oriented policies over the High Arctic. Next, I present the international catalysts that prompt and condition these polices and their specifically settler-colonial tenor. Finally, in line with the Foucauldian imperative to support the “resurrection of subjugated knowledges” (Foucault 2003, 7), I conclude by offering some of the Inuit ways of resisting and reshaping these policies, proving how the Inuit shaped Canadian Arctic sovereignty as much as Canadian Arctic sovereignty policies shaped the Inuit.

Evaluating Arctic meteorology modelled with the Unified Model and Integrated Forecasting System

2020 ◽  
Author(s):  
Gillian Young ◽  
Jutta Vüllers ◽  
Peggy Achtert ◽  
Paul Field ◽  
Jonathan Day ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Sea Ice ◽  
Weather Forecasting ◽  
Numerical Models ◽  
Model Performance ◽  
High Arctic ◽  
Unified Model ◽  
Surface Energy Budget ◽  
The Arctic ◽  
Forecasting System

<p>State-of-the-art numerical models such as the UK Met Office Unified Model and European Centre for Medium-Range Weather Forecasting Integrated Forecasting System are crucial tools for forecasting future Arctic warming. However, their ability to reproduce clouds and boundary layer meteorology in the high Arctic has not been thoroughly evaluated following significant model developments over the last 10 years. Model evaluation is key to understanding where remaining process weaknesses lie, thus informing further parametrization developments to improve the simulated surface energy budget.</p><p>Here, we evaluate model performance with comparison to observations made during the Arctic Ocean 2018 expedition, where a suite of remote-sensing instrumentation was active aboard the Swedish icebreaker <em>Oden </em>measuring summertime Arctic cloud and boundary layer properties. We find that both models do not reproduce cloud fractions well at altitude (up to 8 km) and overestimate the occurrence of low (<1 km) clouds during the sea ice melt period of the expedition. Low cloud agreement with observations improves when the sea ice begins to refreeze; however, the underestimation of cloud aloft remains consistent regardless of sea ice conditions. In this presentation, we will indicate which model processes need to be improved to capture these summertime Arctic clouds more effectively.</p>

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