Drifting away: implications of changes in ice conditions for a pack-ice-breeding phocid, the harp seal (Pagophilus groenlandicus)

2011 ◽  
Vol 89 (11) ◽  
pp. 1050-1062 ◽  
Author(s):  
C.E. Bajzak ◽  
M.O. Hammill ◽  
G.B. Stenson ◽  
S. Prinsenberg
Keyword(s):  
Spatial Distribution ◽  
Spatial Scales ◽  
Ice Cover ◽  
Harp Seal ◽  
First Year ◽  
Ice Coverage ◽  
Pagophilus Groenlandicus ◽  
Pack Ice ◽  
Ice Conditions ◽  
Northwestern Coast

Harp seals ( Pagophilus groenlandicus (Erxleben, 1777)) required drifting pack-ice for birth, nursing, and as a resting platform for neonates after weaning. Data on the yearly location of whelping patches in the Gulf of St. Lawrence collected between 1977 and 2011 were combined with ice cover data (thickness and duration) to examine whether female harp seals actively select particular ice features as a breeding platform and to describe how these ice features have varied over the last 40 years at three spatial scales: the entire Gulf of St. Lawrence, the southern gulf, and the “traditional whelping area” within the southern Gulf. From our analyses, harp seals prefer the thickest ice stages available in the Gulf: grey–white and first-year ice. Lower than normal ice coverage years were more frequent for the required grey–white and first-year ice than for the total ice cover and less frequent at the “traditional whelping area” scale close to the northwestern coast of the Magdalen Islands than at the Gulf of St. Lawrence scale. The frequency of light ice years increased and the duration of the ice season decreased throughout the last decade. Our study showed that the temporal availability and the spatial distribution of the suitable ice are important when evaluating the effect of changes in ice conditions rather than overall ice extent.

scholarly journals Estimation of harp seal (Pagophilus groenlandicus) pup production in the North Atlantic completed: results from surveys in the Greenland Sea in 2002

2006 ◽  
Vol 63 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Tore Haug ◽  
Garry B. Stenson ◽  
Peter J. Corkeron ◽  
Kjell T. Nilssen
Keyword(s):  
North Atlantic ◽  
Barents Sea ◽  
Temporal Distribution ◽  
Harp Seal ◽  
Greenland Sea ◽  
The North ◽  
Pagophilus Groenlandicus ◽  
Pack Ice ◽  
Photographic Survey ◽  
Strip Transect

Abstract From 14 March to 6 April 2002 aerial surveys were carried out in the Greenland Sea pack ice (referred to as the “West Ice”), to assess the pup production of the Greenland Sea population of harp seals, Pagophilus groenlandicus. One fixed-wing twin-engined aircraft was used for reconnaissance flights and photographic strip transect surveys of the whelping patches once they had been located and identified. A helicopter assisted in the reconnaissance flights, and was used subsequently to fly visual strip transect surveys over the whelping patches. The helicopter was also used to collect data for estimating the distribution of births over time. Three harp seal breeding patches (A, B, and C) were located and surveyed either visually or photographically. Results from the staging flights suggest that the majority of harp seal females in the Greenland Sea whelped between 16 and 21 March. The calculated temporal distribution of births were used to correct the estimates obtained for Patch B. No correction was considered necessary for Patch A. No staging was performed in Patch C; the estimate obtained for this patch may, therefore, be slightly negatively biased. The total estimate of pup production, including the visual survey of Patch A, both visual and photographic surveys of Patch B, and photographic survey of Patch C, was 98 500 (s.e. = 16 800), giving a coefficient of variation of 17.9% for the survey. Adding the obtained Greenland Sea pup production estimate to recent estimates obtained using similar methods in the Northwest Atlantic (in 1999) and in the Barents Sea/White Sea (in 2002), it appears that the entire North Atlantic harp seal pup production, as determined at the turn of the century, is at least 1.4 million animals per year.

scholarly journals Variability scaling and consistency in airborne and satellite altimetry measurements of Arctic sea ice

2020 ◽  
Vol 14 (2) ◽  
pp. 751-767
Author(s):  
Shiming Xu ◽  
Lu Zhou ◽  
Bin Wang
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Snow Depth ◽  
Spatial Scales ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
First Year ◽  
Noise Levels ◽  
Wide Range

Abstract. Satellite and airborne remote sensing provide complementary capabilities for the observation of the sea ice cover. However, due to the differences in footprint sizes and noise levels of the measurement techniques, as well as sea ice's variability across scales, it is challenging to carry out inter-comparison or consistently study these observations. In this study we focus on the remote sensing of sea ice thickness parameters and carry out the following: (1) the analysis of variability and its statistical scaling for typical parameters and (2) the consistency study between airborne and satellite measurements. By using collocating data between Operation IceBridge and CryoSat-2 (CS-2) in the Arctic, we show that consistency exists between the variability in radar freeboard estimations, although CryoSat-2 has higher noise levels. Specifically, we notice that the noise levels vary among different CryoSat-2 products, and for the European Space Agency (ESA) CryoSat-2 freeboard product the noise levels are at about 14 and 20 cm for first-year ice (FYI) and multi-year ice (MYI), respectively. On the other hand, for Operation IceBridge and NASA's Ice, Cloud, and land Elevation Satellite (ICESat), it is shown that the variability in snow (or total) freeboard is quantitatively comparable despite more than a 5-year time difference between the two datasets. Furthermore, by using Operation IceBridge data, we also find widespread negative covariance between ice freeboard and snow depth, which only manifests on small spatial scales (40 m for first-year ice and about 80 to 120 m for multi-year ice). This statistical relationship highlights that the snow cover reduces the overall topography of the ice cover. Besides this, there is prevalent positive covariability between snow depth and snow freeboard across a wide range of spatial scales. The variability and consistency analysis calls for more process-oriented observations and modeling activities to elucidate key processes governing snow–ice interaction and sea ice variability on various spatial scales. The statistical results can also be utilized in improving both radar and laser altimetry as well as the validation of sea ice and snow prognostic models.

scholarly journals Observing regional-scale pack-ice decay processes with helicopter-borne sensors and moored upward-looking sonars

2011 ◽  
Vol 52 (57) ◽  
pp. 35-42 ◽  
Author(s):  
Simon J. Prinsenberg ◽  
Ingrid K. Peterson
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Spatial Scales ◽  
Regional Scale ◽  
Global Climate Models ◽  
First Year ◽  
Coarse Scale ◽  
Interaction Processes ◽  
Pack Ice ◽  
Ice Floes

AbstractThe variability of Arctic pack-ice parameters (e.g. extent and ice type) has been monitored by satellite-borne sensors since the early 1960s, and information on ice thickness is now becoming available from satellite altimeters. However, the spatial resolution of satellite-derived ice properties is too coarse to validate fine-scale ice variability generated by regional-scale interaction processes that affect the coarse-scale pack-ice albedo, strength and decay. To understand these regional processes, researchers rely on other data-monitoring platforms such as moored upward-looking sonars and helicopter-borne sensors. Backed by observations, two such regional-scale pack-ice decay processes are discussed: the break-up of large pack-ice floes by long-period waves generated by distant storms, and the spring decay of first-year-ice ridges in a diverging pack-ice environment. These two processes, although occurring on regional spatial scales, are important contributors to the evolution of the total pack ice and need to be included in global climate models, especially as the conditions for their occurrence will alter due to climate change.

Interaction of Vessel with Channel under Navigation among Small Ice Floes

2015 ◽  
Author(s):  
Vadim K. Goncharov ◽  
Ekaterina S. Zueva ◽  
Natalia Yu. Klementieva
Keyword(s):  
Ice Cover ◽  
Problem Definition ◽  
Arctic Seas ◽  
Cross Sectional ◽  
Side Force ◽  
Pack Ice ◽  
Cross Sectional Dimension ◽  
Ice Conditions ◽  
Fast Ice ◽  
Ice Floes

For maintenance of navigation during wintertime in Arctic seas, icebreakers create the wide channels in the fast ice cover or pack ice cover at water areas near to ports with intensive vessel traffic. Within such wide channels cargo ships and tankers can move in both directions independently without icebreaker pilotage among small ice floes. Because the cross-sectional dimension of the channel is restricted, the ships are forced to displace from the center and move on a close distance between their board and border of channel. The space between ship hull and borders is filled by small ice floes, and its concentration near the starboard and portside differs. The ice resistance on each board also differs. Therefore, side force and yawing moment arise that are able to cause the collision with the channel border. This paper contains the detailed problem definition and the main points of the mathematical model of vessel interaction with the channel border. As an example of model application possibilities, the simulation of loads on the hull of the vessel was performed. Outcomes of the investigation are dependent upon the side force and yawing moment on the distance from the channel border and ice conditions.

scholarly journals Multiproxy evidence of the Neoglacial expansion of Atlantic Water to eastern Svalbard: Does ancient environmental DNA complement sedimentary and microfossil records?

2019 ◽  
Author(s):  
Joanna Pawłowska ◽  
Magdalena Łącka ◽  
Małgorzata Kucharska ◽  
Jan Pawlowski ◽  
Marek Zajączkowski
Keyword(s):  
Sea Ice ◽  
Dna Sequences ◽  
Environmental Changes ◽  
Environmental Dna ◽  
Open Water ◽  
Ice Cover ◽  
Atlantic Water ◽  
Ice Coverage ◽  
Ice Conditions ◽  
Multiproxy Approach

Abstract. The main goal of this study was to reconstruct the paleoceanographic development of Storfjorden during the Neoglacial (~ 4 cal ka BP). A multiproxy approach was applied to provide evidence for interactions between the inflow of Atlantic Water (AW) and sea-ice coverage, which are the major drivers of environmental changes in Storfjorden. The sedimentary and microfossil records indicate that a major reorganization of oceanographic conditions in Storfjorden occurred at ~ 2.7 cal ka BP. A general cooling and the less pronounced presence of AW in Storfjorden during the early phase of the Neoglacial are prerequisite conditions for the formation of an extensive sea-ice cover. The period after ~ 2.7 cal ka BP was characterized by alternating short-term cooling and warming intervals. Warming was associated with pulsed inflows of AW and sea-ice melting that stimulated phytoplankton blooms and organic matter supply to the bottom. The cold phases were characterized by heavy and densely packed sea ice resulting in a decrease in productivity. The ancient environmental DNA (aDNA) records of foraminifera and diatoms reveal the timing of the major pulses of AW (~ 2.3 and ~ 1.7 cal ka BP) and the variation in sea-ice cover. The AW inflow was marked by an increase in the percentage of DNA sequences of monothalamous foraminifera associated with the presence of fresh phytodetritus, while cold and less productive intervals were marked by an increased proportion of monothalamous taxa known only from environmental sequencing. The diatom aDNA record indicates that primary production was continuous during the Neoglacial regardless of sea-ice conditions. However, the colder periods were characterized by the presence of diatom taxa associated with sea ice, whereas the present-day diatom assemblage is dominated by open-water taxa.

scholarly journals Multiproxy evidence of the Neoglacial expansion of Atlantic Water to eastern Svalbard

2020 ◽  
Vol 16 (2) ◽  
pp. 487-501 ◽  
Author(s):  
Joanna Pawłowska ◽  
Magdalena Łącka ◽  
Małgorzata Kucharska ◽  
Jan Pawlowski ◽  
Marek Zajączkowski
Keyword(s):  
Sea Ice ◽  
Dna Sequences ◽  
Environmental Changes ◽  
Environmental Dna ◽  
Open Water ◽  
Ice Cover ◽  
Atlantic Water ◽  
Arctic Water ◽  
Ice Coverage ◽  
Ice Conditions

Abstract. The main goal of this study is to reconstruct the paleoceanographic development of Storfjorden during the Neoglacial (∼4 cal ka BP). Storfjorden is one of the most important brine factories in the European Arctic and is responsible for deepwater production. Moreover, it is a climate-sensitive area influenced by two contrasting water masses: warm and saline Atlantic Water (AW) and cold and fresh Arctic Water (ArW). Herein, a multiproxy approach was applied to provide evidence for existing interactions between the inflow of AW and sea ice coverage, which are the major drivers of environmental changes in Storfjorden. The sedimentary and microfossil records indicate that a major reorganization of oceanographic conditions in Storfjorden occurred at ∼2.7 cal ka BP. The cold conditions and the less pronounced presence of AW in Storfjorden during the early phase of the Neoglacial were the prerequisite conditions for the formation of extensive sea ice cover. The period after ∼2.7 cal ka BP was characterized by alternating short-term cooling and warming intervals. Warming was associated with pulsed inflows of AW and sea ice melting that stimulated phytoplankton blooms and organic matter supply to the bottom. The cold phases were characterized by heavy and densely packed sea ice, resulting in decreased productivity. The ancient environmental DNA (aDNA) records of foraminifera and diatoms support the occurrence of the major pulses of AW (∼2.3 and ∼1.7 cal ka BP) and the variations in sea ice cover. The episodes of enhanced AW inflow were marked by an increase in the percentage of DNA sequences of monothalamous foraminifera associated with the presence of fresh phytodetritus. Cold and less productive intervals were marked by an increased proportion of monothalamous taxa known only from environmental sequencing. The diatom aDNA record indicates that primary production was continuous during the Neoglacial, regardless of the sea ice conditions. However, the colder periods were characterized by the presence of diatom taxa associated with sea ice, whereas the present-day diatom assemblage is dominated by open-water taxa.

scholarly journals Sea ice cover in Isfjorden and Hornsund 2000–2014 by using remote sensing

2015 ◽  
Vol 9 (4) ◽  
pp. 4043-4066
Author(s):  
S. Muckenhuber ◽  
F. Nilsen ◽  
A. Korosov ◽  
S. Sandven
Keyword(s):  
Sea Ice ◽  
Open Water ◽  
Ice Cover ◽  
Ice Coverage ◽  
Time Period ◽  
Ice Drift ◽  
Before And After ◽  
Ice Conditions ◽  
Fast Ice ◽  
The Mean

Abstract. A satellite database including 16 555 satellite images and ice charts displaying the area of Isfjorden, Hornsund and the Svalbard region has been established with focus on the time period 2000–2014. 3319 manual interpretations of sea ice conditions have been conducted, resulting in two time series dividing the area of Isfjorden and Hornsund into "Fast ice", "Drift ice" and open "Water". The maximum fast ice coverage of Isfjorden is > 40 % in the periods 2000–2005 and 2009–2011 and stays < 30 % in 2006–2008 and 2012–2014. Fast ice cover in Hornsund reaches > 40 % in all considered years, except for 2012 and 2014, where the maximum stays < 20 %. The mean seasonal cycles of fast ice in Isfjorden and Hornsund show monthly averaged values of less than 1 % between July and November and maxima in March (Isfjorden, 35.7 %) and April (Hornsund, 42.1 %) respectively. A significant reduction of the monthly averaged fast ice coverage is found when comparing the time periods 2000–2005 and 2006–2014. The seasonal maximum decreases from 57.5 to 23.2 % in Isfjorden and from 52.6 to 35.2 % in Hornsund. A new concept, called "days of fast ice coverage" (DFI), is introduced for quantification of the interannual variation of fast ice cover, allowing for comparison between different fjords and winter seasons. Considering the time period from 1 March until end of sea ice season, the mean DFI values for 2000–2014 are 33.1 ± 18.2 DFI (Isfjorden) and 42.9 ± 18.2 DFI (Hornsund). A distinct shift to lower DFI values is observed in 2006. Calculating a mean before and after 2006 yields a decrease from 50 to 22 DFI for Isfjorden and from 56 to 34 DFI for Hornsund.

scholarly journals Ice Features Of The Northern Caspian Under Sea Level Fluctuations And Ice Coverage Variations

2020 ◽  
Vol 13 (3) ◽  
pp. 129-138
Author(s):  
Stanislav A. Ogorodov ◽  
Anastasiia A. Magaeva ◽  
Stepan V. Maznev ◽  
Natalia A. Yaitskaya ◽  
Sergey Vernyayev ◽  
...  
Keyword(s):  
Sea Level ◽  
Oil And Gas ◽  
Ice Cover ◽  
Water Level Fluctuations ◽  
Sea Levels ◽  
Sea Level Fluctuations ◽  
Oil And Gas Fields ◽  
Ice Coverage ◽  
Aerial Reconnaissance ◽  
Ice Conditions

The  Caspian Seaseasonal ice cover develops  each  winter despite  of it being  in mid-latitudes.  Increasing development of oil and gas fields challenges researchers to ensure operational safety. TheCaspian Seahas seen significant water level fluctuations in its recent history. And in the same time, it is vulnerable to effects of climate change. Extensive studies on ice conditions conducted  in the region don’t provide insights on influence of these factors in combination to describe ice cover behavior and ice features distribution.  We classify winter seasons of theNorthern Caspianby their severity calculating the cumulative freezing-degree days (CFDD). Ice charts based on aerial reconnaissance with support of the OSI-450 reanalysis provided data on the ice coverage, the timing of ice formation and destruction, the duration of the ice seasons from 1979 to 2015. We analyzed the stamukhi distribution on theNorthern Caspianfrom aerial reconnaissance for 1973–1980 and satellite imagery deciphering for 2013–2019  periods along with sea level dynamics. We found out that the amount of severe and moderate winters reduces while mild winters number increases. This leads to a decrease in the mean ice area and ice duration at theNorthern Caspian. Comparison of two periods with different sea levels and ice coverage showed that both factors affect the distribution of stamukhi by depth and distance to coast in theNorthern Caspian. Comparison of stamukhi locations in moderate winter seasons showed that their distribution is determined by the area of ice cover. In case of similar ice conditions, the stamukhi distribution is determined by sea level. The zone of their highest concentration shifts along with the coastline offset.

scholarly journals Variability Scaling and Consistency of Airborne and Satellite Altimetry Measurements of Arctic Sea Ice

2019 ◽  
Author(s):  
Shiming Xu ◽  
Lu Zhou ◽  
Bin Wang
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Snow Depth ◽  
Spatial Scales ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
First Year ◽  
Noise Levels ◽  
Wide Range

Abstract. Satellite and airborne remote sensing provide complementary capabilities for the observation of the sea ice cover. However, due to the differences in footprint sizes and noise levels of the measurement techniques, as well as sea ice's variability across scales, it is challenging to carry out inter-comparison or consistency study of these observations. In this study we focus on the remote sensing of sea ice thickness parameters, and carry out: (1) the analysis of variability and its statistical scaling for typical parameters, and (2) the consistency study between airborne and satellite measurements. By using collocating data between Operation IceBridge and CryoSat-2 in the Arctic, we show that there exists consistency between the variability of radar freeboard estimations, although CryoSat-2 has higher noise levels. Specifically, we notice that the noise levels vary among different CryoSat-2 products, and for ESA CryoSat-2 freeboard product the noise levels are at about 14 and 20 cm for first-year and multiyear ice, respectively. On the other hand, for Operation IceBridge and ICESat, it is shown that the variability of snow (or total) freeboard is quantitatively comparable, despite over 5 years' the time difference between the two datasets. Furthermore, by using Operation IceBridge data, we also find wide-spread negative covariance between ice freeboard and snow depth, which only manifest at small spatial scales (40 m for first-year ice and about 80 to 120 m for MYI). This statistical relationship highlights that the snow cover reduces the overall topography of the ice cover. Besides, there is prevalent positive covariability between snow depth and snow freeboard across a wide range of spatial scales. The variability and consistency analysis calls for more process-oriented observations and modeling activities to elucidate key processes governing snow-ice interaction and sea ice variability on various spatial scales. The statistical results can also be utilized in improving both radar and laser altimetry, as well as the validation of sea ice and snow prognostic models.

scholarly journals Seal Occurrence and Habitat Use during Summer in Petermann Fjord, Northwestern Greenland

ARCTIC ◽  
2018 ◽  
Vol 71 (3) ◽  
Author(s):  
Kate Lomac-MacNair ◽  
Martin Jakobsson ◽  
Alan Mix ◽  
Francis Freire ◽  
Kelly Hogan ◽  
...  
Keyword(s):  
Habitat Use ◽  
Ice Cover ◽  
High Arctic ◽  
Distribution Data ◽  
Hooded Seal ◽  
Nares Strait ◽  
Ice Coverage ◽  
Ringed Seals ◽  
Pagophilus Groenlandicus ◽  
Bearded Seals

Ice-associated seals are considered especially susceptible and are potentially the first to modify distribution and habitat use in response to physical changes associated with the changing climate. Petermann Glacier, part of a unique ice-tongue fjord environment in a rarely studied region of northwestern Greenland, lost substantial sections of its ice tongue during major 2010 and 2012 calving events. As a result, changes in seal habitat may have occurred. Seal occurrence and distribution data were collected in Petermann Fjord and adjacent Nares Strait region over 27 days (2 to 28 August) during the multidisciplinary scientific Petermann 2015 Expedition on the icebreaker Oden. During 239.4 hours of dedicated observation effort, a total of 312 individuals were recorded, representing four species: bearded seal (Erignathus barbatus), hooded seal (Crystophora cristata), harp seal (Pagophilus groenlandicus), and ringed seal (Pusa hispida). Ringed seals were recorded significantly more than the other species (χ2 = 347.4, df = 3, p < 0.001, n = 307). We found significant differences between species in haul-out (resting on ice) behavior (χ2 = 133.1, df = 3, p < 0.001, n = 307). Bearded seals were more frequently hauled out (73.1% n = 49), whereas ringed seals were almost exclusively in water (93.9%, n = 200). Differences in average depth and ice coverage where species occurred were also significant: harp seals and bearded seals were found in deeper water and areas of greater ice coverage (harp seals: 663 ± 366 m and 65 ± 14% ice cover; bearded seals: 598 ± 259 m and 50 ± 21% ice cover), while hooded seals and ringed seals were found in shallower water with lower ice coverage (hooded seals: 490 ± 163 m and 38 ± 19% ice cover; ringed seals: 496 ± 235 m, and 21 ± 20% ice cover). Our study provides an initial look at how High Arctic seals use the rapidly changing Petermann Fjord and how physical variables influence their distribution in one of the few remaining ice-tongue fjord environments.

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