Zou Zou Kuzyk - Academia.edu (original) (raw)

Papers by Zou Zou Kuzyk

Communications Earth & Environment

Despite their wide use in past sea-ice reconstructions, the seasonal, habitat and species-based s... more Despite their wide use in past sea-ice reconstructions, the seasonal, habitat and species-based sources of sedimentary sea-ice proxies are poorly understood. Here, we conduct direct observations of the community composition of diatoms, dinoflagellate cysts and highly branched isoprenoid lipids within the sea ice, water column, sediment traps and sediment surface in the Belcher Islands Archipelago, Hudson Bay throughout spring 2019. We find that Arctic diatom and dinoflagellate cysts species commonly used as sea-ice proxies appear to be only indirectly linked to sea-ice conditions, and that the sediment assemblages of these groups overrepresent summertime pelagic blooms. Species contributing to the diverse sea-ice diatom communities are rare in the sediment. Dinoflagellate cysts form a typical Arctic assemblage in the sediment, although they are virtually absent in the sea ice and water column in spring. We also find that certain highly branched isoprenoid lipids that were previously...

Science of The Total Environment

To date, sediment cores have been successfully collected, while aboard the CCGS Sir Wilfrid Lauri... more To date, sediment cores have been successfully collected, while aboard the CCGS Sir Wilfrid Laurier in July 2007, and the CCGS Louis S. St. Laurent in July, 2009. The suite of cores spans the continental shelf and slope at depths varying from 60 to 2000 m from the Bering and Chukchi Seas, to Barrow Canyon, to the Mackenzie Shelf, Davis Strait, Baffin Bay and Canadian Archipelago. The analysis of the samples is now completed and we are now working on the interpretation of results. There is a lot that can be learned from the sediment cores. So far, the results show strong differences in the sediments and organic carbon between different regions of the Arctic. Areas that are very productive with algae and the marine food web, like the North Water Polynya in northern Baffin Bay, have very different organic carbon cycles from areas near river mouths that are strongly influenced by the land. We plan to characterize each region in detail and also compare the regions to produce an overall p...

Internal waves in the Arctic regions have been of recent scientific interest due to their role in... more Internal waves in the Arctic regions have been of recent scientific interest due to their role in vertical mixing, and their consequent influence on the heat budget of the upper ocean and ice cover. Until now there were no internal tidal waves observation in Hudson Bay. As evidenced by SAR remote sensing imagery, the Belcher Islands archipelago is one of the most active region for internal tidal wave generation in Hudson Bay due to its unique shoreline, bottom topography and proximity to an amphidromical point. Here we present and examine the first ever collected for the studied region temperature, salinity and current velocity data from the ice tethered mooring deployed in an ice covered narrow channel between Broomfield and O’Leary islands located in the south-east tip of Belcher islands group in Hudson Bay and discuss a possible impact of internal tidal waves on water mass characteristics.

Internal Tidal Wave Propagation under the Landfast Sea Ice in the Southeast Hudson Bay. Hudson Ba... more Internal Tidal Wave Propagation under the Landfast Sea Ice in the Southeast Hudson Bay. Hudson Bay (HB) is a second largest saltwater bay in the world. It is relatively shallow with average depth of 100m and high tidal amplitudes (up to about 4m). Several major rivers are discharging into HB currently being regulated due to hydro dam development causing freshwater discharge to increase in winter months. All these factors makes HB a unique oceanographic system for study atmospheric-oceanographic coupling and freshwater impact. During January-March 2014 the CTD survey was conducted around Belcher islands in the southeastern HB. An ice-tethered mooring consisting of 9 conductivity and temperature (CT) sensors and acoustic Doppler current profiler (ADCP) was deployed in a narrow channel between Broomfield and O’Leary islands located in the south east tip of Belcher islands group in HB as a part of an oceanographic monitoring program in that region. The CTD profiles show the surface freshened layer caused by cyclonic circulation of river runoff water in Hudson Bay. In the bottom layer, warm and saline water was recorded increasing meridionally towards the south. Such layer preserved in the south due to presence of salinity/density vertical stratification that prevents vertical mixing. The mooring recorded semidiurnal oscillations of temperature and salinity through the whole water column. Our objective was to examine the origin of this temperature and salinity variability. The tidal analysis was performed for M2 as main tidal constitutes. The tidal ellipses were computed for horizontal velocity at various depths with overlay of corresponding salinity and temperature values. From the mooring time series the M2 temperature and salinity amplitudes were calculate for each depth. These plots as well as the tidal ellipses showed a pattern typical for internal waves. Based on velocity, temperature and salinity data and tidal analysis we came to conclusion that our mooring recorded internal tidal waves produced from interaction of tides with bathymetry of the narrow channel between Broomfield and O’Leary islands

A mooring equipped with two acoustic Doppler current profilers (ADCP) and a sediment trap was dep... more A mooring equipped with two acoustic Doppler current profilers (ADCP) and a sediment trap was deployed in September 2016 in Hudson Bay at 59° 58.156’ N 91° 57.144’ W (~190 km north-east from the port of Churchill). The backscatter intensity and vertical velocity time series from the mooring ADCPs showed a pattern typical for the zooplankton diel vertical migration (DVM) under sea ice during winter. To correct for beam geometry, we derived volume backscatter strength from echo intensity. Actograms were built for the volume backscatter strength, vertical velocity and modelled lunar light. An upward looking ADCP was capable to record the ice thickness and periods of open water above the mooring. The sediment trap captured different types of zooplankton that allow identifying the scatters involved in DVM. From the acquired data we observed the interaction of vertical migration with lunar light, tides, water and sea ice dynamics. The presented data constitutes a first-ever observed presence of DVM in Hudson Bay during winter.

1 .pdf copy (1 Pag.) of the exhaustive abstract published by the Organization. © Author(s) 2015. ... more 1 .pdf copy (1 Pag.) of the exhaustive abstract published by the Organization. © Author(s) 2015. CC Attribution 3.0 License.

Elementa: Science of the Anthropocene, 2021

During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed... more During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed sediment-laden sea ice were encountered unexpectedly in southern Hudson Bay and presented difficult navigation conditions for the Canadian Coast Guard Ship Amundsen. An aerial survey of one of these floes revealed a maximum ridge height of 4.6 m and an average freeboard of 2.2 m, which corresponds to an estimated total thickness of 18 m, far greater than expected within a seasonal ice cover. Samples of the upper portion of the ice floe revealed that it was isothermal and fresh in areas with sediment present on the surface. Fine-grained sediment and larger rocks were visible on the ice surface, while a pronounced sediment band was observed in an ice core. Initial speculation was that this ice had formed in the highly dynamic Nelson River estuary from freshwater, but δ18O isotopic analysis revealed a marine origin. In southern Hudson Bay, significant tidal forcing promotes both sediment r...

Continental Shelf Research, 2021

Abstract Hudson Bay (Canada) is the world's largest inland sea, which receives upward of ~700... more Abstract Hudson Bay (Canada) is the world's largest inland sea, which receives upward of ~700 km3 of river discharge annually. Cyclonic water circulation transports this riverine water along the coast toward Hudson Strait and into the Labrador Sea. Yearlong observations of the current velocity profile, collected from an array of oceanographic moorings deployed in western Hudson Bay from September 2016 to September–October 2017, show that cyclonic wind forcing amplifies cyclonic water circulation in Hudson Bay and favours cross-shelf exchange. Cyclonic storms generate synoptic variability of salinity in the coastal regions, which remains poorly understood. Here we use temperature, salinity and Colored Dissolved Organic Matter (CDOM) fluorescence data from the same mooring array to examine the role of atmospheric forcing on variability of temperature and salinity in western Hudson Bay. We find that in terms of the storm-driven variability, the Nelson River estuary is impacted by river runoff year round because the Nelson River flow is regulated. Our data show that cyclonic storms intensify outflow from the Nelson River estuary. This water is also high in CDOM originating from terrestrial organic matter. Thus, the storm-driven cross-shelf displacement of the estuarial water generates a negative correlation between salinity and CDOM. The upstream Hudson Bay area ~250 km northwest of the Nelson River estuary is found to be marine dominated. In this area, cyclonic storms force the surface marine water onshore, generating storm surge along the coast. During summer, the offshore water is saline and higher in CDOM than the inshore water presumably because of a marine DOM component. Thus, the storm-driven onshore displacement of this saline (marine dominated) water generates positive anomalies of salinity and CDOM, resulting in positive correlation between salinity and CDOM during summer-fall. In contrast, during winter the onshore water becomes saltier than the offshore water due to the southward alongshore transport of saline water generated in the upstream Northwest Hudson Bay polynya. The onshore displacement of water from the Hudson Bay interior during winter cyclonic storms generates negative salinity anomalies recorded by our mooring. Since there is no marine primary production during winter, the CDOM is not impacted significantly by winter cyclonic wind forcing.

Elementa: Science of the Anthropocene, 2021

Hudson Bay, at the southern margin of the Arctic Ocean, receives nearly one-third of Canada’s riv... more Hudson Bay, at the southern margin of the Arctic Ocean, receives nearly one-third of Canada’s river discharge and approximately 5.5 Tg of riverine dissolved organic carbon (DOC) annually. Riverine DOC fluxes to Hudson Bay are expected to increase with climate change, but how this increase will influence the biogeochemistry of the coastal waters is largely unknown. In particular, the fate of riverine DOC that enters Hudson Bay during the dark, frozen winter period (roughly January to April) is poorly known despite high discharge from the large, regulated rivers of Hudson and James Bays at that time. Few studies have assessed the degradability of riverine DOC transported in winter anywhere across the Arctic, leaving unanswered questions regarding the impact of riverine DOC on the Arctic carbon budget, CO2 fluxes, and local food webs. Here, we assessed the biodegradability of DOC in riverine and coastal waters of southern Hudson Bay in late winter using 45-day incubation experiments. W...

Estuaries and Coasts, 2020

The Hudson Bay system is undergoing climate-driven changes in sea ice and freshwater inflow and h... more The Hudson Bay system is undergoing climate-driven changes in sea ice and freshwater inflow and has seen an increase in winter river inflow since the 1960s due in part to flow regulation for hydropower production. Southeast Hudson Bay and adjacent James Bay are at the forefront of these changes, with more than 1-month shortening of the season of sea ice cover as defined using satellite data, increases in winter inflow from the regulated La Grande River complex, and changes in coastal ice and polynya behavior described by Belcher Islands’ Inuit. In summer, there is a fresh coastal domain in southeast Hudson Bay fueled by river runoff and sea ice melt. To investigate winter oceanographic conditions and potential interactions between runoff and ice melt or brine in southeast Hudson Bay, we initiated the first winter study of the shallow waters surrounding the Belchers, collecting conductivity-temperature-depth (CTD) profiles and conductivity-temperature (CT) time series using under-ice...

Marine Geology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Continental Shelf Research, 2018

The location of the amphidromic point of the M2 tide in Hudson Bay roughly coincides with Belcher... more The location of the amphidromic point of the M2 tide in Hudson Bay roughly coincides with Belcher Islands, a region where the surface mixed layer stays relatively fresh throughout summer and winter due to significant ice melt and river discharge. High-resolution satellite radar imagery for the ice-free season revealed that the coastal region in the southeast Belcher Islands is a hot spot for short-period internal wave activity. For a first investigation of tidal dynamics in the region, we took advantage of the sea ice platform to deploy an ice-tethered mooring consisting of nine conductivity and temperature sensors and an acoustic Doppler current profiler. The mooring was deployed at 65 m depth in January-March 2014 in a narrow channel between Broomfield and O′Leary islands located in the southeast tip of the Belcher Islands group in Hudson Bay (56°20′N, 79°30′W), northeast Canada. The surface mixed layer under the land-fast ice in this area stays relatively fresh through winter presumably because of significant winter river discharge in nearby James Bay. The mooring recorded oscillations of temperature and salinity throughout the whole water column, which were attributed to vertical displacement caused by internal tidal waves. The tidal harmonic analysis performed for the M 2 tidal constituent showed the dominance of the baroclinic tide with maximum velocity amplitudes at the surface and decreasing with depth. Vertical displacements of water parcels derived from both temperature and salinity were statistically similar and displayed the maximum values of 11.9 m at 35 m (instrument depth). The combination of winter hydrographic data and summer satellite observations confirmed that the observed internal waves were generated by the interaction of strong tides, typical for Hudson Bay, with highly variable bottom topography southeast of the Belcher Islands archipelago.

Hudson Bay is a large seasonally ice-covered Canadian inland sea connected to the Arctic Ocean an... more Hudson Bay is a large seasonally ice-covered Canadian inland sea connected to the Arctic Ocean and North Atlantic through Foxe Basin and Hudson Strait. This study investigates zooplankton distribution, dynamics, and factors controlling them during open-water and ice cover periods (from September 2016 to October 2017) in Hudson Bay. A mooring equipped with two acoustic Doppler current profilers (ADCPs) and a sediment trap was deployed in September 2016 in Hudson Bay ∼ 190 km northeast from the port of Churchill. The backscatter intensity and vertical velocity time series showed a pattern typical for zooplankton diel vertical migration (DVM). The sediment trap collected five zooplankton taxa including two calanoid copepods (Calanus glacialis and Pseudocalanus spp.), a pelagic sea snail (Limacina helicina), a gelatinous arrow worm (Parasagitta elegans), and an amphipod (Themisto libellula). From the acquired acoustic data we observed the interaction of DVM with multiple factors including lunar light, tides, and water and sea ice dynamics. Solar illuminance was the major factor determining migration pattern, but unlike at some other polar and subpolar regions, moonlight had little effect on DVM, while tidal dynamics are important. The presented data constitute the first-ever observed DVM in Hudson Bay during winter and its interaction with the tidal dynamics.

Communications Earth & Environment

Despite their wide use in past sea-ice reconstructions, the seasonal, habitat and species-based s... more Despite their wide use in past sea-ice reconstructions, the seasonal, habitat and species-based sources of sedimentary sea-ice proxies are poorly understood. Here, we conduct direct observations of the community composition of diatoms, dinoflagellate cysts and highly branched isoprenoid lipids within the sea ice, water column, sediment traps and sediment surface in the Belcher Islands Archipelago, Hudson Bay throughout spring 2019. We find that Arctic diatom and dinoflagellate cysts species commonly used as sea-ice proxies appear to be only indirectly linked to sea-ice conditions, and that the sediment assemblages of these groups overrepresent summertime pelagic blooms. Species contributing to the diverse sea-ice diatom communities are rare in the sediment. Dinoflagellate cysts form a typical Arctic assemblage in the sediment, although they are virtually absent in the sea ice and water column in spring. We also find that certain highly branched isoprenoid lipids that were previously...

Science of The Total Environment

To date, sediment cores have been successfully collected, while aboard the CCGS Sir Wilfrid Lauri... more To date, sediment cores have been successfully collected, while aboard the CCGS Sir Wilfrid Laurier in July 2007, and the CCGS Louis S. St. Laurent in July, 2009. The suite of cores spans the continental shelf and slope at depths varying from 60 to 2000 m from the Bering and Chukchi Seas, to Barrow Canyon, to the Mackenzie Shelf, Davis Strait, Baffin Bay and Canadian Archipelago. The analysis of the samples is now completed and we are now working on the interpretation of results. There is a lot that can be learned from the sediment cores. So far, the results show strong differences in the sediments and organic carbon between different regions of the Arctic. Areas that are very productive with algae and the marine food web, like the North Water Polynya in northern Baffin Bay, have very different organic carbon cycles from areas near river mouths that are strongly influenced by the land. We plan to characterize each region in detail and also compare the regions to produce an overall p...

Internal waves in the Arctic regions have been of recent scientific interest due to their role in... more Internal waves in the Arctic regions have been of recent scientific interest due to their role in vertical mixing, and their consequent influence on the heat budget of the upper ocean and ice cover. Until now there were no internal tidal waves observation in Hudson Bay. As evidenced by SAR remote sensing imagery, the Belcher Islands archipelago is one of the most active region for internal tidal wave generation in Hudson Bay due to its unique shoreline, bottom topography and proximity to an amphidromical point. Here we present and examine the first ever collected for the studied region temperature, salinity and current velocity data from the ice tethered mooring deployed in an ice covered narrow channel between Broomfield and O’Leary islands located in the south-east tip of Belcher islands group in Hudson Bay and discuss a possible impact of internal tidal waves on water mass characteristics.

Internal Tidal Wave Propagation under the Landfast Sea Ice in the Southeast Hudson Bay. Hudson Ba... more Internal Tidal Wave Propagation under the Landfast Sea Ice in the Southeast Hudson Bay. Hudson Bay (HB) is a second largest saltwater bay in the world. It is relatively shallow with average depth of 100m and high tidal amplitudes (up to about 4m). Several major rivers are discharging into HB currently being regulated due to hydro dam development causing freshwater discharge to increase in winter months. All these factors makes HB a unique oceanographic system for study atmospheric-oceanographic coupling and freshwater impact. During January-March 2014 the CTD survey was conducted around Belcher islands in the southeastern HB. An ice-tethered mooring consisting of 9 conductivity and temperature (CT) sensors and acoustic Doppler current profiler (ADCP) was deployed in a narrow channel between Broomfield and O’Leary islands located in the south east tip of Belcher islands group in HB as a part of an oceanographic monitoring program in that region. The CTD profiles show the surface freshened layer caused by cyclonic circulation of river runoff water in Hudson Bay. In the bottom layer, warm and saline water was recorded increasing meridionally towards the south. Such layer preserved in the south due to presence of salinity/density vertical stratification that prevents vertical mixing. The mooring recorded semidiurnal oscillations of temperature and salinity through the whole water column. Our objective was to examine the origin of this temperature and salinity variability. The tidal analysis was performed for M2 as main tidal constitutes. The tidal ellipses were computed for horizontal velocity at various depths with overlay of corresponding salinity and temperature values. From the mooring time series the M2 temperature and salinity amplitudes were calculate for each depth. These plots as well as the tidal ellipses showed a pattern typical for internal waves. Based on velocity, temperature and salinity data and tidal analysis we came to conclusion that our mooring recorded internal tidal waves produced from interaction of tides with bathymetry of the narrow channel between Broomfield and O’Leary islands

A mooring equipped with two acoustic Doppler current profilers (ADCP) and a sediment trap was dep... more A mooring equipped with two acoustic Doppler current profilers (ADCP) and a sediment trap was deployed in September 2016 in Hudson Bay at 59° 58.156’ N 91° 57.144’ W (~190 km north-east from the port of Churchill). The backscatter intensity and vertical velocity time series from the mooring ADCPs showed a pattern typical for the zooplankton diel vertical migration (DVM) under sea ice during winter. To correct for beam geometry, we derived volume backscatter strength from echo intensity. Actograms were built for the volume backscatter strength, vertical velocity and modelled lunar light. An upward looking ADCP was capable to record the ice thickness and periods of open water above the mooring. The sediment trap captured different types of zooplankton that allow identifying the scatters involved in DVM. From the acquired data we observed the interaction of vertical migration with lunar light, tides, water and sea ice dynamics. The presented data constitutes a first-ever observed presence of DVM in Hudson Bay during winter.

1 .pdf copy (1 Pag.) of the exhaustive abstract published by the Organization. © Author(s) 2015. ... more 1 .pdf copy (1 Pag.) of the exhaustive abstract published by the Organization. © Author(s) 2015. CC Attribution 3.0 License.

Elementa: Science of the Anthropocene, 2021

During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed... more During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed sediment-laden sea ice were encountered unexpectedly in southern Hudson Bay and presented difficult navigation conditions for the Canadian Coast Guard Ship Amundsen. An aerial survey of one of these floes revealed a maximum ridge height of 4.6 m and an average freeboard of 2.2 m, which corresponds to an estimated total thickness of 18 m, far greater than expected within a seasonal ice cover. Samples of the upper portion of the ice floe revealed that it was isothermal and fresh in areas with sediment present on the surface. Fine-grained sediment and larger rocks were visible on the ice surface, while a pronounced sediment band was observed in an ice core. Initial speculation was that this ice had formed in the highly dynamic Nelson River estuary from freshwater, but δ18O isotopic analysis revealed a marine origin. In southern Hudson Bay, significant tidal forcing promotes both sediment r...

Continental Shelf Research, 2021

Abstract Hudson Bay (Canada) is the world's largest inland sea, which receives upward of ~700... more Abstract Hudson Bay (Canada) is the world's largest inland sea, which receives upward of ~700 km3 of river discharge annually. Cyclonic water circulation transports this riverine water along the coast toward Hudson Strait and into the Labrador Sea. Yearlong observations of the current velocity profile, collected from an array of oceanographic moorings deployed in western Hudson Bay from September 2016 to September–October 2017, show that cyclonic wind forcing amplifies cyclonic water circulation in Hudson Bay and favours cross-shelf exchange. Cyclonic storms generate synoptic variability of salinity in the coastal regions, which remains poorly understood. Here we use temperature, salinity and Colored Dissolved Organic Matter (CDOM) fluorescence data from the same mooring array to examine the role of atmospheric forcing on variability of temperature and salinity in western Hudson Bay. We find that in terms of the storm-driven variability, the Nelson River estuary is impacted by river runoff year round because the Nelson River flow is regulated. Our data show that cyclonic storms intensify outflow from the Nelson River estuary. This water is also high in CDOM originating from terrestrial organic matter. Thus, the storm-driven cross-shelf displacement of the estuarial water generates a negative correlation between salinity and CDOM. The upstream Hudson Bay area ~250 km northwest of the Nelson River estuary is found to be marine dominated. In this area, cyclonic storms force the surface marine water onshore, generating storm surge along the coast. During summer, the offshore water is saline and higher in CDOM than the inshore water presumably because of a marine DOM component. Thus, the storm-driven onshore displacement of this saline (marine dominated) water generates positive anomalies of salinity and CDOM, resulting in positive correlation between salinity and CDOM during summer-fall. In contrast, during winter the onshore water becomes saltier than the offshore water due to the southward alongshore transport of saline water generated in the upstream Northwest Hudson Bay polynya. The onshore displacement of water from the Hudson Bay interior during winter cyclonic storms generates negative salinity anomalies recorded by our mooring. Since there is no marine primary production during winter, the CDOM is not impacted significantly by winter cyclonic wind forcing.

Elementa: Science of the Anthropocene, 2021

Hudson Bay, at the southern margin of the Arctic Ocean, receives nearly one-third of Canada’s riv... more Hudson Bay, at the southern margin of the Arctic Ocean, receives nearly one-third of Canada’s river discharge and approximately 5.5 Tg of riverine dissolved organic carbon (DOC) annually. Riverine DOC fluxes to Hudson Bay are expected to increase with climate change, but how this increase will influence the biogeochemistry of the coastal waters is largely unknown. In particular, the fate of riverine DOC that enters Hudson Bay during the dark, frozen winter period (roughly January to April) is poorly known despite high discharge from the large, regulated rivers of Hudson and James Bays at that time. Few studies have assessed the degradability of riverine DOC transported in winter anywhere across the Arctic, leaving unanswered questions regarding the impact of riverine DOC on the Arctic carbon budget, CO2 fluxes, and local food webs. Here, we assessed the biodegradability of DOC in riverine and coastal waters of southern Hudson Bay in late winter using 45-day incubation experiments. W...

Estuaries and Coasts, 2020

The Hudson Bay system is undergoing climate-driven changes in sea ice and freshwater inflow and h... more The Hudson Bay system is undergoing climate-driven changes in sea ice and freshwater inflow and has seen an increase in winter river inflow since the 1960s due in part to flow regulation for hydropower production. Southeast Hudson Bay and adjacent James Bay are at the forefront of these changes, with more than 1-month shortening of the season of sea ice cover as defined using satellite data, increases in winter inflow from the regulated La Grande River complex, and changes in coastal ice and polynya behavior described by Belcher Islands’ Inuit. In summer, there is a fresh coastal domain in southeast Hudson Bay fueled by river runoff and sea ice melt. To investigate winter oceanographic conditions and potential interactions between runoff and ice melt or brine in southeast Hudson Bay, we initiated the first winter study of the shallow waters surrounding the Belchers, collecting conductivity-temperature-depth (CTD) profiles and conductivity-temperature (CT) time series using under-ice...

Marine Geology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Continental Shelf Research, 2018

The location of the amphidromic point of the M2 tide in Hudson Bay roughly coincides with Belcher... more The location of the amphidromic point of the M2 tide in Hudson Bay roughly coincides with Belcher Islands, a region where the surface mixed layer stays relatively fresh throughout summer and winter due to significant ice melt and river discharge. High-resolution satellite radar imagery for the ice-free season revealed that the coastal region in the southeast Belcher Islands is a hot spot for short-period internal wave activity. For a first investigation of tidal dynamics in the region, we took advantage of the sea ice platform to deploy an ice-tethered mooring consisting of nine conductivity and temperature sensors and an acoustic Doppler current profiler. The mooring was deployed at 65 m depth in January-March 2014 in a narrow channel between Broomfield and O′Leary islands located in the southeast tip of the Belcher Islands group in Hudson Bay (56°20′N, 79°30′W), northeast Canada. The surface mixed layer under the land-fast ice in this area stays relatively fresh through winter presumably because of significant winter river discharge in nearby James Bay. The mooring recorded oscillations of temperature and salinity throughout the whole water column, which were attributed to vertical displacement caused by internal tidal waves. The tidal harmonic analysis performed for the M 2 tidal constituent showed the dominance of the baroclinic tide with maximum velocity amplitudes at the surface and decreasing with depth. Vertical displacements of water parcels derived from both temperature and salinity were statistically similar and displayed the maximum values of 11.9 m at 35 m (instrument depth). The combination of winter hydrographic data and summer satellite observations confirmed that the observed internal waves were generated by the interaction of strong tides, typical for Hudson Bay, with highly variable bottom topography southeast of the Belcher Islands archipelago.

Hudson Bay is a large seasonally ice-covered Canadian inland sea connected to the Arctic Ocean an... more Hudson Bay is a large seasonally ice-covered Canadian inland sea connected to the Arctic Ocean and North Atlantic through Foxe Basin and Hudson Strait. This study investigates zooplankton distribution, dynamics, and factors controlling them during open-water and ice cover periods (from September 2016 to October 2017) in Hudson Bay. A mooring equipped with two acoustic Doppler current profilers (ADCPs) and a sediment trap was deployed in September 2016 in Hudson Bay ∼ 190 km northeast from the port of Churchill. The backscatter intensity and vertical velocity time series showed a pattern typical for zooplankton diel vertical migration (DVM). The sediment trap collected five zooplankton taxa including two calanoid copepods (Calanus glacialis and Pseudocalanus spp.), a pelagic sea snail (Limacina helicina), a gelatinous arrow worm (Parasagitta elegans), and an amphipod (Themisto libellula). From the acquired acoustic data we observed the interaction of DVM with multiple factors including lunar light, tides, and water and sea ice dynamics. Solar illuminance was the major factor determining migration pattern, but unlike at some other polar and subpolar regions, moonlight had little effect on DVM, while tidal dynamics are important. The presented data constitute the first-ever observed DVM in Hudson Bay during winter and its interaction with the tidal dynamics.