scholarly journals A decadal perspective on north water microbial eukaryotes as Arctic Ocean sentinels

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nastasia J. Freyria ◽  
Nathalie Joli ◽  
Connie Lovejoy
Keyword(s):  
Surface Waters ◽  
18S Rrna ◽  
Open Water ◽  
Amplicon Sequencing ◽  
Ice Formation ◽  
Seasonal Patterns ◽  
The North ◽  
Microbial Eukaryotes ◽  
Water Region ◽  
North Water

AbstractThe North Water region, between Greenland and Ellesmere Island, with high populations of marine birds and mammals, is an Arctic icon. Due to climate related changes, seasonal patterns in water column primary production are changing but the implications for the planktonic microbial eukaryote communities that support the ecosystem are unknown. Here we report microbial community phenology in samples collected over 12 years (2005–2018) from July to October and analysed using high throughput 18S rRNA V4 amplicon sequencing. Community composition was tied to seasonality with summer communities more variable than distinct October communities. In summer, sentinel pan-Arctic species, including a diatom in the Chaetoceros socialis-gelidus complex and the picochlorophyte Micromonas polaris dominated phytoplankton and were summer specialists. In autumn, uncultured undescribed open water dinoflagellates were favored, and their ubiquity suggests they are sentinels of arctic autumn conditions. Despite the input of nutrients into surface waters, autumn chlorophyll concentrations remained low, refuting projected scenarios that longer ice-free seasons are synonymous with high autumn production and a diatom dominated bloom. Overall, the summer sentinel microbial taxa are persisting, and a subset oceanic dinoflagellate should be monitored for possible ecosystem shifts as later autumn ice formation becomes prevalent elsewhere.

scholarly journals Applications of Satellite Thermal Infrared Images for Monitoring North Water during the Periods of Polar Darkness

1980 ◽  
Vol 25 (93) ◽  
pp. 425-438
Author(s):  
B. Dey
Keyword(s):  
Satellite Images ◽  
Open Water ◽  
Thermal Infrared ◽  
Water Area ◽  
Infrared Images ◽  
Baffin Bay ◽  
The North ◽  
Thermal Infrared Images ◽  
North Water

AbstractThe study reported here illustrates the unique value of NOAA thermal infrared (TIR) images for monitoring the North Water area in Smith Sound and northern Baffin Bay during the periods of polar darkness. Wintertime satellite images reveal that, during the months of December through February, open water and thin ice occur in a few leads and polynyas. However, in March, the areas of open water and thin ice decrease to a minimum with a consequent higher concentration of ice. Two ice dams, in northern Kennedy Channel and in northern Smith Sound, regulate the flow of ice into northern Baffin Bay and also determine the areal variations of open water and thin ice in Smith Sound.

scholarly journals Ice Conditions of an Arctic Polynya: North Water in Winter

1986 ◽  
Vol 32 (112) ◽  
pp. 383-390 ◽  
Author(s):  
Konrad Steffen
Keyword(s):  
Sea Water ◽  
Surface Condition ◽  
Open Water ◽  
Sea Surface ◽  
Aerial Images ◽  
The Arctic ◽  
The North ◽  
North Water ◽  
Ice Conditions ◽  
Fast Ice

AbstractThe surface condition of the North Water was investigated during two winters (i.e. the three polynyas: Smith Sound polynya, Lady Ann Strait polynya, and Barrow Strait polynya). Since no detailed information was available on ice conditions and the extent of open water during winter, radiometric temperature measurements of the sea surface had to be taken along a flight line of 2650 km from an altitude of 300 m. From November to March 1978-79 and 1980-81, 14 remote-sensing flights were carried out. On the basis of the radiometric measurements, the following ice types were identified: ice-free, dark nilas, light nilas, grey ice, grey-white ice, and white ice. A comparison between the thermal and the visual ice classification (the latter being based on grey tones of the aerial images) showed a deviation of 3%. The analysis showed that in November, December, and January more than 50% of the Smith Sound polynya was covered by young ice, nilas, and ice-free, whereas in February and March white ice was dominant. Moreover, it was found that the two polynyas in Smith Sound and Lady Ann Strait were much smaller than previously believed. In Barrow Strait, a semi-permanent polynya was observed in the winter of 1980-81. The occurrence of polynyas in Barrow Strait seems to be connected with the location of the fast-ice edge. On the basis of the calculated ice-type distribution and heat-flux rates for different ice types, an energy loss of 178 W m-2was found on the surface of the Smith Sound polynya due to open water and thin ice for the winter months November to March. Compared with other ice-covered sea surfaces in the Arctic, the heat release by the sea-water in the Smith Sound polynya is about 100 W m-2larger.

Variation in Lake Water Temperature in the Nanticoke Region of Long Point Bay, Lake Erie, during the Open-Water Season

1990 ◽  
Vol 47 (7) ◽  
pp. 1427-1433 ◽  
Author(s):  
T. G. Dunstall ◽  
D. W. Lawler ◽  
R. Farooqui ◽  
G. T. Haymes
Keyword(s):  
Water Temperature ◽  
Surface Waters ◽  
Lake Water ◽  
Lake Erie ◽  
Heat Content ◽  
Open Water ◽  
The North ◽  
Heating And Cooling ◽  
Recovery Times ◽  
Warming Cycle

Lake water temperature on the north shore of Long Point Bay near Nanticoke (Lake Erie) over the years 1971–83 varied considerably during the lake warming cycle. Upwellings, resulting in temperature drops of 5–10°C over a 2–3 d period, were common from mid-May to mid-August. Warmer surface waters returned within 6 d (usually 3 d) following summer upwellings. In spring, the recovery times were variable but typically lasted longer, up to 25 d. Temperature fluctuations that exceeded 5°C but lasted less than 48 h were also frequent during the lake warming cycle. The progressive deepening of the epilimnion to the 12-m depth of Long Point Bay and the associated increase in the heat content of the Bay resulted in a stable temperature regime by mid-August. Diurnal heating and cooling of surface waters, by as much as 4°C, was apparent under calm conditions. Mean April–November temperatures varied by more than 2°C, reflecting annual variation in atmospheric warming.

scholarly journals Abundance of Atlantic walrus in Western Nares Strait, Baffin Bay Stock, during summer

2014 ◽  
Vol 9 ◽  
pp. 123 ◽  
Author(s):  
Robert EA Stewart ◽  
Erik W Born ◽  
Rune Dietz ◽  
Mads Peter Heide-Jørgensen ◽  
Frank Farsø Rigét ◽  
...  
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Ellesmere Island ◽  
Baffin Bay ◽  
Nares Strait ◽  
The North ◽  
North Water Polynya ◽  
Odobenus Rosmarus ◽  
North Water ◽  
Odobenus Rosmarus Rosmarus

Atlantic walruses (Odobenus rosmarus rosmarus) belonging to the Baffin Bay subpopulation occur year round in the North Water polynya (NOW) between NW Greenland and eastern Ellesmere Island (Canada). They are hunted for subsistence purposes by residents of the Qaanaaq area (NW Greenland) bordering the NOW to the east and by Canadian Inuit at the entrance to Jones Sound in Nunavut. During the open-water period NW Greenland is virtually devoid of walruses which concentrate along eastern and southern Ellesmere Island at this time of the year. To determine the abundance of walruses in the NOW area, aerial surveys were conducted in August of 1999, 2008, and 2009. In July 2009, nine satellite-linked transmitters were deployed in nearby Kane Basin. Surveys on 9 and 20 August 2009 along eastern Ellesmere Island were the most extensive and were augmented with concomitant data on haul-out and at water surface activity from three (1 F, 2 M) of the nine tags that were still functioning. We therefore focus on the 2009 surveys. Walruses were observed on the ice and in water primarily in Buchanan Bay and Princess Marie Bay where the remaining functional tags were located. The Minimum Counted population (MCP) was 571 on 20 August. Adjusting the MCP of walruses on ice for those not hauled out, the estimate of abundance of walruses in the Baffin Bay stock was 1,251(CV=1.00, 95% CI = 1,226) when adjusted by the proportion of tags ‘dry’ at the time of the survey and 1,249 (CV=1.12, 95% CI = 1,370) when adjusted by the average time tags were dry. The surveys did not cover all potential walrus summering habitat along eastern Ellesmere Island and are negatively biased to an unknown degree.

An on-ice aerial survey of the Kane Basin polar bear (Ursus maritimus) subpopulation

Polar Biology ◽  
2021 ◽  
Author(s):  
Øystein Wiig ◽  
Stephen N. Atkinson ◽  
Erik W. Born ◽  
Seth Stapleton ◽  
Todd Arnold ◽  
...  
Keyword(s):  
Distance Sampling ◽  
Open Water ◽  
High Arctic ◽  
Ursus Maritimus ◽  
Aerial Survey ◽  
Arctic Sea Ice ◽  
Line Transect ◽  
Polar Bears ◽  
The North ◽  
North Water

AbstractThere is an imminent need to collect information on distribution and abundance of polar bears (Ursus maritimus) to understand how they are affected by the ongoing decrease in Arctic sea ice. The Kane Basin (KB) subpopulation is a group of high-latitude polar bears that ranges between High Arctic Canada and NW Greenland around and north of the North Water polynya (NOW). We conducted a line transect distance sampling aerial survey of KB polar bears during 28 April–12 May 2014. A total of 4160 linear kilometers were flown in a helicopter over fast ice in the fjords and over offshore pack ice between 76° 50′ and 80° N′. Using a mark-recapture distance sampling protocol, the estimated abundance was 190 bears (95% lognormal CI: 87–411; CV 39%). This estimate is likely negatively biased to an unknown degree because the offshore sectors of the NOW with much open water were not surveyed because of logistical and safety reasons. Our study demonstrated that aerial surveys may be a feasible method for obtaining abundance estimates for small subpopulations of polar bears.

scholarly journals Ice Conditions of an Arctic Polynya: North Water in Winter

1986 ◽  
Vol 32 (112) ◽  
pp. 383-390 ◽  
Author(s):  
Konrad Steffen
Keyword(s):  
Sea Water ◽  
Surface Condition ◽  
Open Water ◽  
Sea Surface ◽  
Aerial Images ◽  
The Arctic ◽  
The North ◽  
North Water ◽  
Ice Conditions ◽  
Fast Ice

AbstractThe surface condition of the North Water was investigated during two winters (i.e. the three polynyas: Smith Sound polynya, Lady Ann Strait polynya, and Barrow Strait polynya). Since no detailed information was available on ice conditions and the extent of open water during winter, radiometric temperature measurements of the sea surface had to be taken along a flight line of 2650 km from an altitude of 300 m. From November to March 1978-79 and 1980-81, 14 remote-sensing flights were carried out. On the basis of the radiometric measurements, the following ice types were identified: ice-free, dark nilas, light nilas, grey ice, grey-white ice, and white ice. A comparison between the thermal and the visual ice classification (the latter being based on grey tones of the aerial images) showed a deviation of 3%. The analysis showed that in November, December, and January more than 50% of the Smith Sound polynya was covered by young ice, nilas, and ice-free, whereas in February and March white ice was dominant. Moreover, it was found that the two polynyas in Smith Sound and Lady Ann Strait were much smaller than previously believed. In Barrow Strait, a semi-permanent polynya was observed in the winter of 1980-81. The occurrence of polynyas in Barrow Strait seems to be connected with the location of the fast-ice edge. On the basis of the calculated ice-type distribution and heat-flux rates for different ice types, an energy loss of 178 W m-2 was found on the surface of the Smith Sound polynya due to open water and thin ice for the winter months November to March. Compared with other ice-covered sea surfaces in the Arctic, the heat release by the sea-water in the Smith Sound polynya is about 100 W m-2 larger.

scholarly journals Energy flux density estimation over sea ice based on satellite passive microwave measurements

1991 ◽  
Vol 15 ◽  
pp. 178-183 ◽  
Author(s):  
Konrad Steffen
Keyword(s):  
Flux Density ◽  
Density Estimation ◽  
Energy Flux ◽  
Passive Microwave ◽  
Microwave Measurements ◽  
Polarization Ratio ◽  
The North ◽  
Water Region ◽  
North Water ◽  
Energy Flux Density

This paper discusses in detail the energy flux density estimation at the ice/atmosphere interface over the entire North Water region, based on the ice-type distribution during the winter (1978/79 to 1985/86). The analysis is based on passive microwave measurements of the scanning multichannel microwave radiometer (SMMR) onboard the Nimbus 7 satellite. Based on the relation of increasing polarization ratio (18 or 37 GHz) with decreasing ice thickness, a threshold technique was applied to classify the different young ice types. The polarization ratio method seems feasible for climatological applications, such as energy flux density estimations, over large areas with homogeneous young ice. More than 20% young ice (<0.3m) was found in the North Water area (100,000 km2) throughout most winters, with maximal values of 60% and more, and only a few percent of open water were classified. In general, the young ice cover in the North Water was decreasing towards the end of the winter. The mean energy loss for the entire North Water region was found to be 77 W m−2 for the months of November to March. Considering an energy supply by refreezing of 38 W m−2, the remaining 39 W m−2 must be withdrawn from the enthalpy in the sea water.

21.—The History of the North Water

1972 ◽  
Vol 72 (1) ◽  
pp. 231-241 ◽  
Author(s):  
Moira Dunbar ◽  
M. J. Dunbar
Keyword(s):  
Open Water ◽  
Baffin Island ◽  
The West ◽  
Baffin Bay ◽  
The North ◽  
Open Sea ◽  
Bylot Island ◽  
North Water ◽  
North Part ◽  
History Of

In 1616 William Baffin, coasting up the icebound west coast of Greenland, reported: ‘The first of July we were come into an open sea, in the latitude of 75 degrees 40 minutes, which a new revived our hope of a passage…’ (Purchas 1625). From this point, at an unspecified longitude in the north part of Melville Bay, he cruised for 12 days in open water, up the Greenland coast to 77°30'N and down the west side of Baffin Bay to Bylot Island, seeing and naming on the way Smith, Jones, and Lancaster sounds. From Bylot Island south he found ‘a ledge of ice between the shoare and us’ as he continued past Pond Inlet and down the coast of Baffin Island. This is the first mention in written records, and the first known navigation, of an area that became well known two centuries later as the ‘North Water’.

scholarly journals Energy flux density estimation over sea ice based on satellite passive microwave measurements

1991 ◽  
Vol 15 ◽  
pp. 178-183 ◽  
Author(s):  
Konrad Steffen
Keyword(s):  
Flux Density ◽  
Density Estimation ◽  
Energy Flux ◽  
Passive Microwave ◽  
Microwave Measurements ◽  
Polarization Ratio ◽  
The North ◽  
Water Region ◽  
North Water ◽  
Energy Flux Density

This paper discusses in detail the energy flux density estimation at the ice/atmosphere interface over the entire North Water region, based on the ice-type distribution during the winter (1978/79 to 1985/86). The analysis is based on passive microwave measurements of the scanning multichannel microwave radiometer (SMMR) onboard the Nimbus 7 satellite. Based on the relation of increasing polarization ratio (18 or 37 GHz) with decreasing ice thickness, a threshold technique was applied to classify the different young ice types. The polarization ratio method seems feasible for climatological applications, such as energy flux density estimations, over large areas with homogeneous young ice. More than 20% young ice (&lt;0.3m) was found in the North Water area (100,000 km2) throughout most winters, with maximal values of 60% and more, and only a few percent of open water were classified. In general, the young ice cover in the North Water was decreasing towards the end of the winter. The mean energy loss for the entire North Water region was found to be 77 W m−2for the months of November to March. Considering an energy supply by refreezing of 38 W m−2, the remaining 39 W m−2must be withdrawn from the enthalpy in the sea water.

scholarly journals Applications of Satellite Thermal Infrared Images for Monitoring North Water during the Periods of Polar Darkness

1980 ◽  
Vol 25 (93) ◽  
pp. 425-438 ◽  
Author(s):  
B. Dey
Keyword(s):  
Satellite Images ◽  
Open Water ◽  
Thermal Infrared ◽  
Water Area ◽  
Infrared Images ◽  
Baffin Bay ◽  
The North ◽  
Thermal Infrared Images ◽  
North Water

AbstractThe study reported here illustrates the unique value of NOAA thermal infrared (TIR) images for monitoring the North Water area in Smith Sound and northern Baffin Bay during the periods of polar darkness. Wintertime satellite images reveal that, during the months of December through February, open water and thin ice occur in a few leads and polynyas. However, in March, the areas of open water and thin ice decrease to a minimum with a consequent higher concentration of ice. Two ice dams, in northern Kennedy Channel and in northern Smith Sound, regulate the flow of ice into northern Baffin Bay and also determine the areal variations of open water and thin ice in Smith Sound.

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