Northeast Water Research Articles

Houston's Northeast Water Purification Plant Completes Phase 1 Expansion

Houston's Northeast Water Purification Plant Completes Phase 1 Expansion

The Northeast Water Polynya, Greenland: Climatology, Atmospheric Forcing and Ocean Response

AbstractThe Northeast Water Polynya is a significant annually recurring summertime Arctic polynya, located off the coast of Northeast Greenland. It is important for marine wildlife and affects local atmospheric and oceanic processes. In this study, over 40 years of observational and reanalysis products (ERA5 and ORAS5) are analyzed to characterize the polynya's climatology and ascertain forcing mechanisms. The Northeast Water Polynya has high spatiotemporal variability; its location, size and structure vary interannually, and the period for which it is open is changing. We show this variability is largely driven by atmospheric forcing. The polynya extent is determined by the direction of the near‐surface flow regime, and the relative locations of high and low sea‐level pressure centers over the region. The surface conditions also impact the oceanic water column, which has a strong seasonal cycle in potential temperature and salinity, the amplitude of which decreases with depth. The ocean reanalyses also show a significant warming trend at all depths and a freshening near the surface consistent with greater ice melt, but salinification at lower depths (∼200 m). As the Arctic region changes due to anthropogenic forcing, the sea‐ice edge is migrating northwards and the Northeast Water Polynya is generally opening earlier and closing later in the year. This could have significant implications for both the atmosphere and ocean in this complex and rapidly changing environment.

Weakened pelagic-benthic coupling on an Arctic outflow shelf (Northeast Greenland) suggested by benthic ecosystem changes

Arctic marine ecosystems are becoming more boreal due to climate change. Predictions of ecosystem change focus mainly on Arctic inflow or interior shelves, with few comprehensive studies on Arctic outflow regions. During September–October 2017, soft-bottom communities were sampled and benthic ecosystem processes were quantified at 12 stations on the Northeast Greenland shelf (outflow shelf) and compared to the last regional ecosystem study, conducted in 1992 and 1993. The benthic habitat was characterized in terms of sediment granulometry, pigment concentrations, and porewater chemistry (dissolved inorganic carbon, nutrients). Total abundance and biomass of macrobenthos and meiobenthos, bacterial abundance, porewater dissolved inorganic carbon and ammonium concentrations were higher on the outer shelf compared to locations adjacent to the Nioghalvfjerdsfjorden glacier at 79°N and the inner shelf stations (e.g., macrofauna: 1,964–2,952 vs. 18–1,381 individuals m−2). These results suggest higher benthic production in the outer parts of the NEG shelf. This difference was also pronounced in macrobenthic and meiobenthic community structure, which was driven mainly by food availability (pigments with 1.3–4.3 vs. 0.3–0.9 µg g−1 sediment, higher total organic carbon content and bacterial abundance). Compared to the early 1990s, warmer bottom water temperatures, increased number of sea-ice-free days and lower sediment pigment concentrations in 2017 were accompanied by decreased polychaete and increased nematode abundance and diversity, and a different community structure of nematode genera. The present study confirms previous reports of strong pelagic-benthic coupling on the NEG shelf, but highlights a possible weakening since the early 1990s, with a potential shift in importance from macrofauna to meiofauna in the benthic community. Increasing inflow of Atlantic water and decreasing volume transport and thickness of sea ice through the Fram Strait, probably affecting the Northeast Water Polynya, may be responsible, suggesting ecosystem-wide consequences of continued changes in sea-ice patterns on Arctic shelves.

Alexios G. C. Savvides, Bosphorus/Bosporos (Boghaz-içi) from Byzantine to Latin and Ottoman Times (4th–15th Centuries): Constantinople Viewed from the North-East Water Currents. Athens: Herodotos, 2020. 238 pages, 2 maps. ISBN: 9789604853816

Review of Alexios G. C. Savvides, Bosphorus/Bosporos (Boghaz-içi) from Byzantine to Latin and Ottoman Times (4th–15th Centuries): Constantinople Viewed from the North-East Water Currents. Athens: Herodotos, 2020. 238 pages, 2 maps. ISBN: 9789604853816 by Daniele Tinterri

Distribution of modern benthic foraminiferal assemblages across the Northeast Greenland continental shelf

Analysis of benthic foraminifera in surface samples from 23 sites on the Northeast Greenland continental shelf reveal key assemblage differences between sites. Cluster analysis creates two clear geographical faunal assemblage zones: the 1) inner shelf, and 2) mid and outer shelf sites. These assemblages differ significantly, with the inner shelf sites being characterised by a high percentage and concentration of calcareous species, whilst the mid and outer shelf sites are dominated by agglutinated taxa. At almost all sites, the calcareous assemblages are dominated by Cassidulina neoteretis and Cassidulina reniforme, suggesting that they thrive across the shelf. Stetsonia horvathi, Oridorsalis tener, as well as Glomulina oculus and other miliolid species are found to be key calcareous species at many sites in the inner shelf zone, but they are rare-to-absent on the mid and outer shelf. Canonical correspondence analysis shows that September sea-ice cover and bottom water oxygen content are positively correlated with benthic foraminiferal assemblages at inner shelf sites, whereas organic carbon content is correlated with those in the mid and outer shelf. The formation of seasonal sea-ice and the Northeast Water polynya rejects brine into surrounding waters and transports CO2 to the seafloor, creating a highly corrosive environment for calcium carbonate. These environments are also highly productive, as indicated by the high organic carbon content and low bottom water oxygen content. The oxidation of this organic material creates CO2. We propose that these processes are key drivers in the dissolution of calcareous tests. In contrast, extensive sea-ice, high bottom water oxygen content and low primary productivity in the glacier-proximal region facilitates carbonate preservation.

Assessment of habitat and reef fish population characteristics in Pari Island cluster waters Seribu Archipelago Indonesia

The Pari Island Cluster, located on the Southside of the Seribu Archipelago, is bordered by Jakarta and Tangerang Regency is covered Pari, Kudus, and Tikus Islands. The Pari Island cluster has potential ecosystems, such as coral reefs, seagrass, and mangrove. The presentation of this article is an overview of the results of research conducted by the Research Institute for Marine Fisheries and the Research Institute for Fisheries Enhancement, The Agency for Marine and Fisheries Research and Human Resources. This study aims to present and describe habitat and reef fish populations. The assessment result shows that the criteria for the coral reefs’ health were poor to good, mostly moderate, the best in the southeast and northeast waters, which had been designated MPAs. Reef fish population density on the criteria was very rare or low at all observation sites. The dominant group was Caesio cuning, Cephalopholis boenak, Scarus ghobban (target group), and Chaetodon octofasciatus (indicator group). The implementation hopes Pari Island Cluster waters would expand to be designated MPAs due to the large number of care areas used for fishing territories.

Review of Bosphorus/Bosporus (Boghaz-İçi) from Byzantine to Latin and Ottoman Times (4th–15th Centuries): Constantinople Viewed from the Northeast Water Currents


 
 
 Bosphorus/Bosporus (Boghaz-İçi) from Byzantine to Latin and Ottoman Times (4th–15th Centuries): Constantinople Viewed from the Northeast Water Currents. By Alexios G. C. Savvides. Athens: Hêrotodos, 2020. Pp. 238. €30.
 
 

Mapping of Active Frazil and Sea Ice Production in the Northern Hemisphere, With Comparison to the Southern Hemisphere

AbstractFrazil ice in the coastal polynyas has been increasingly recognized as important for efficient sea ice production, associated dense water formation, transport of particulate matter and consequent biological production. However, it has not been well understood where and to what degree active‐frazil areas occur in the Northern Hemisphere polynyas. We presented the first mapping of active frazil in the Northern Hemisphere, using sea ice data during September–May for 2002/2003–2010/2011, created from an Advanced Microwave Scanning Radiometer for the Earth Observing System thin ice algorithm that can detect active frazil areas. The North Water, Northeast Water, Anadyr, and St. Lawrence Island polynyas were found to have a relatively high occurrence rate of active frazil compared with other polynyas. We improved the estimation of sea ice production by discriminating between active frazil and thin solid ice and found that previous algorithms tended to overestimate sea ice production, particularly for polynyas dominated by thin solid ice such as the Okhotsk Northwestern polynya. We also made the first global comparison of polynya characteristics for all the major coastal polynyas. The annual ice production rate is 3–4 m yr−1 in the Northern Hemisphere polynyas and 6–9 m yr−1 in the Antarctic coastal polynyas. This large difference is mainly explained by the less frequent occurrence of active frazil and thin ice areas in the Northern Hemisphere polynyas owing to a lower occurrence of strong wind events.

Resource partitioning may limit interspecific competition among Arctic fish species during early life

Arctic cod (Boreogadus saida) strongly dominates the ichthyoplankton assemblages of High Arctic seas, hence competition with other native species seldom has been studied. Yet, interspecific competition could negatively impact the survival of early life stages of fishes in Arctic areas where higher diversity prevails. We surveyed the ichthyoplankton community of the Greenland Sea, in August–September 2017. Gadids (mostly Arctic cod, with a low number of ice cod Arctogadus glacialis) and non-gadids (bigeye sculpin Triglops nybelini and gelatinous snailfish Liparis fabricii) co-dominated age-0 fish assemblages. Here, we document their diet, prey selectivity, horizontal and vertical distributions as well as that of their prey to assess resource partitioning and the potential for interspecific competition. All fish species occupied the top 30 m of the water column, but Arctic cod occurred in highest abundances over the continental slope, whereas other species distributed almost exclusively over the continental shelf. A particle track analysis suggests that Arctic cod larvae could have hatched in the open waters of the Northeast Water Polynya, drifted with the East Greenland Current, and benefited from the high secondary production associated with these oceanographic features. The diet of gadids did not overlap significantly with the diet of non-gadids, but strong selectivity for Pseudocalanus spp. and Calanus spp. copepodites among the larvae suggests potential competition for these key prey items, although limited by size partitioning of the prey. We thus conclude that interspecific competition among early life stages of Arctic fishes is limited for now. However, changing conditions and the northward range expansion of boreal species following climate change could increase competition and, in turn, negatively affect the recruitment of Arctic ichthyoplankton.

Migration and changing law of PHC content under the action of ocean current

According to the survey dataset of the waters of Jiaozhou Bay in May 1993, this paper studies the migration and changing process of PHC content caused by marine oil spill in the waters of Jiaozhou Bay. In May, take the center of eastern waters, H3107, as the source of marine oil spill, where PHC content is 51.00μg/L. Then a series of concentric circles with different gradients are formed with H3107 station as the center. The PHC content decreases from the high content of 51.00μg/L in the center to the surroundings along the gradient, to 4.16μg/L in the waters of bay mouth, 31.60μg/L in the central waters of the bay, 27.00μg/L in the northern waters, and 48.40μg/L in the northeast waters. According to the horizontal absolute loss rate model of material content, it can be calculated that the value of horizontal absolute loss rate of PHC content in the surface layer of the water body from the eastern center to the bay mouth in May is calculated to be 0.44 Yang Dongfang absolute number; to the central waters of the bay, 0.13 Yang Dongfang absolute number; to the northern waters of the bay, 0.33 Yang Dongfang absolute number; to the northeastern waters of the bay, 0.06 Yang Dongfang absolute number. According to the horizontal relative loss rate model of material content, it is calculated that in May, from the eastern central waters to the waters of bay mouth, the horizontal relative loss rate of PHC content in the surface layer of water body is 8.67 Yang Dongfang relative number; to the central waters of the bay, 2.72 Yang Dongfang relative number; to the northern waters of the bay, 6.47 Yang Dongfang relative number; to the northeastern waters of the bay, 1.33 Yang Dongfang relative number. Therefore, taking H3107, the central point in the eastern part of Jiaozhou Bay, as the source of marine oil spills, its PHC content decreases to the surroundings, whose horizontal absolute loss rate is within 0.06–0.44 Yang Dongfang absolute number and the horizontal relative loss rate is within 1.33–8.67 Yang Dongfang relative number. The order of the horizontal absolute (relative) loss rate of PHC content from low to high is: waters in the northeast of the bay < waters in the bay center < waters in the north of the bay < waters in the bay mouth. The Yang Dongfang horizontal loss rate model of material content reveals the migration and changing law of PHC content during the process of ocean current carrying PHC content: 1) In the downstream direction of the ocean current, the PHC content decreases at the slowest rate, and its loss is the smallest during the migration process. In the countercurrent direction of the ocean current, the PHC content declines the fastest, and the loss is greatest during the migration process. 2) In the downstream direction of the ocean current, as the migration distance continues to increase, the PHC content continues to decline and its loss is gradually increasing during the migration process. 3) In waters where the ocean current does not pass, the PHC content decreases slowly, and the PHC content reaches a relatively high value. During the migration process, its loss is relatively small. The PHC content reaches the waters where the ocean current does not pass, and the loss content is between the loss of the PHC content carried by the ocean current in the downstream direction and the upstream direction.

Quantitative Hg Content Migration Process I. YangDongfang Migration Model Calculation

Based on the investigation data of Jiaozhou Bay in May, August and October, 1992, the migration process of Hg content that came from atmospheric subsidence in Jiaozhou Bay was studied. In August, the central point 2016 in the east of Jiaozhou Bay was taken as the source of atmospheric subsidence, with the Hg content of 0.050 μg/L. A series of concentric circles with different gradients have been formed with station 2016 as the center. The Hg content decreased from 0.050 μg/L in the center to 0.021 μg/L in the center of the Bay, 0.037 μg/L in the northwest, 0.031μg/L in the northeast and 0.033 μg/L in the southeast of the bay. According to the absolutely horizontal loss rate model of matter content, it was calculated that in August, in the eastern part of Jiaozhou Bay, from the eastern central water area to the central water area of the Bay, the absolutely horizontal loss rate of Hg content in the surface was 0.40 Yang Dongfang absolute number, 0.19 Yang Dongfang absolute number in the northwest water area of the bay, 0.45 Yang Dongfang absolute number in the northeast water area of the bay, 0.63 Yang Dongfang absolute number in the southeast water area of the Bay. According to the relatively horizontal loss rate model of matter content, it was calculated that in August, in the eastern part of Jiaozhou Bay, from the eastern central water area to the central water area of the Bay, the relatively horizontal loss rate of Hg content in the surface was 8.00 Yang Dongfang relative number, 3.80 Yang Dongfang relative number in the northwest water area of the Bay, 9.00 Yang Dongfang relative number in the northeast water area of the Bay, 12.60 Yang Dongfang relative number in the southeast water area of the bay.

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Quantitative Hg Content Migration Process II. Yang Dongfang Migration Model Application

Based on the investigation data of Jiaozhou Bay in May, August and October, 1992, the migration process of Hg content that came from atmospheric subsidence in Jiaozhou Bay was studied. In August, the central point 2016 in the east of Jiaozhou Bay was taken as the source of atmospheric subsidence, with the Hg content of 0.050 μg/L. According to the absolutely and relatively horizontal loss rate model of matter content, the results showed the facts: A series of concentric circles with different gradients have been formed with station 2016 as the center. Taking the central station 2016 in the east of Jiaozhou Bay as the source of atmospheric subsidence, the Hg content decreased towards surrounding waters. The absolutely horizontal loss rate value of Hg content was between 0.19-0.63 Yang Dongfang absolute number, and the relatively horizontal loss rate value of Hg content was between 3.80-12.60 Yang Dongfang relative number. The sequence of Hg content from low to high was : the central water area of the bay < the northeast water area of the bay < the southeast water area of the bay < the northwest water area of the bay, and the sequence of Hg content absolutely horizontal(relatively) loss rate value from low to high was : the northwest water area of the bay < the central water area of the bay < the northeast water area of the bay < the southeast water area of the bay. The Hg content showed the starting point value of the source point, the end point value of the water area. And the absolutely(relatively) horizontal loss rate value of the Hg content showed the migration process value of the water area from the starting point to the end point. This revealed that the starting point, end point and process value of Hg content showed the migration process of Hg content in water. According to the Yang Dongfang horizontal loss rate model of substance content, the migration and change process of Hg content decreasing along the gradients to surrounding waters could be calculated and quantified.

Grounded icebergs as maternity denning habitat for polar bears (Ursus maritimus) in North and Northeast Greenland

This study provides the first documentation of polar bear (Ursus maritimus) maternity denning in snowdrifts around icebergs frozen into the fast ice or grounded on the seafloor. Based on six den observations in north and northeast Greenland during spring surveys in 2018 and 2019 (109 flight hours), together with observations of 20 adult females with 35 cubs of the year (COYs) in adjacent sea ice, we hypothesize that the use of snowdrifts around icebergs for maternity denning is an established behavior in the region and not a random event. Factors influencing maternity denning in snowdrifts around icebergs may include limited suitable drifts on the nearby terrestrial polar desert due to low precipitation, the presence of suitable wind-blown snow banks regardless of the direction of autumn storm winds, cold and stable habitat throughout the winter denning period, and access to ringed seal (Pusa hispida) pupping habitat in the nearby Northeast Water polynya. This type of maternity denning habitat is only available in glaciated regions of the Arctic where marine-terminating glaciers deposit melange large enough to become grounded offshore and remain in place for months or years. This habitat may become less stable or disappear with long-term climate warming.

Decreasing and Migration Process of PHC Content in Central Jiaozhou Bay

Based on the survey data of Jiaozhou Bay in May, August and October 1992, the migration and variation of PHC content of the oil spill in Jiaozhou Bay were studied. It was found that oil spill originally occurred in central Jiaozhou Bay in May, and its PHC content was 0.042mg/L. A series of concentric circles with different gradients formed around there, and there was a descended distribution trend from the center to the periphery along the gradient. The content of PHC decreased from 0.042mg/L at the center to 0.012mg/L in the southwest water, 0.024mg/L in the northwest water, 0.012mg/L in the northern water, 0.020mg/L in the northeast water, 0.014mg/L in the eastern water and 0.010 mg/L in the southeast water. The PHC content in these waters ranged from 0.010mg/L to 0.042mg/L. With horizontal absolute loss velocity model of material content, it was calculated that the horizontal absolute loss velocity of PHC content in the surface waters from the central water to the southwest water in May was 0.36 Yang Dongfang absolute number, to the northwest water 0.25 Yang Dongfang absolute number, to the northern water 0.52 Yang Dongfang absolute number, to the northeast water 0.31Yang Dongfang absolute number, to the eastern water 0.58 Yang Dongfang absolute number and to the southeast water 0.50 Yang Dongfang absolute number. Therefore, with the central water of Jiaozhou Bay taken as the source of oil spill at sea, there was a descended PHC content distribution trend from the center to the periphery along the gradient, and the horizontal absolute loss velocity of PHC content ranged from 0.25 Yang Dongfang absolute number to 0.58 Yang Dongfang absolute number. With horizontal relative loss velocity model of material content, it was calculated that the horizontal relative loss velocity of PHC content in the surface waters from the central water to the southwest water of Jiaozhou Bay in May was 8.68 Yang Dongfang relative number, to the northwest water 5.95 Yang Dongfang relative number, to the northern water 12.38 Yang Dongfang relative number, to the northeast water 7.38Yang Dongfang relative number, to the eastern water 13.80 Yang Dongfang relative number and to the southeast water 11.90 Yang Dongfang relative number. Therefore, with the central water of Jiaozhou Bay taken as the source of oil spill at sea, there was a descended PHC content distribution trend from the center to the periphery along the gradient, and the horizontal relative loss velocity of PHC content ranged from 5.95 Yang Dongfang relative number to 13.80 Yang Dongfang relative number. The rising PHC content distribution order was: that of the southeast water < that of the southwest water < that of the northern water <that of the eastern water< that of the northeast water <that of the northwest water. The rising horizontal absolute (relative) loss velocity of PHC content order was: that of the northwest water < that of the northeast water < that of the southwest water <that of the southeast water< that of the northern water <that of the eastern water. With horizontal loss velocity model of Yang Dongfang material content, the terminal value and process value of PHC content form the central water toward the six directions can be calculated.

Decreasing and Migration Process of Oil Spill at Sea

Based on the survey data of Jiaozhou Bay in May, August and October 1992, the migration and variation of PHC content in offshore oil spill in Jiaozhou Bay were studied. In August, Station 2106 at the eastern central Point of Jiaozhou Bay was taken as the source of offshore oil spill, and its PHC content was 0.056 mg/L. A series of concentric circles with different gradients formed around there, and there was a descended distribution trend from the center to the periphery along the gradient. The content of PHC decreased from 0.056 mg/L at the center to 0.024 mg/L in the central water, 0.027 mg/L in the northwest water, 0.041 mg/L in the northeast water and 0.048 mg/L in the southeast water. According to the horizontal absolute loss velocity model of material content, it was calculated that the horizontal absolute loss velocity of PHC content in the surface waters from the eastern central water to the central water of eastern Jiaozhou Bay in August was 0.45 Yang Dongfang absolute number, and it decreased to 0.42 in the northwest water, 0.36 in the northeast water, and 0.29 in the southeast water. According to the horizontal relative loss velocity model of material content, it was calculated that the horizontal relative loss velocity of PHC content in the surface waters from the eastern central water to the central water of eastern Jiaozhou Bay in August was 8.03 Yang Dongfang absolute number, and it decreased to 7.50 in the northwest water, 6.42 in the northeast water, and 5.17 in the southeast water. Therefore, with Station 2106 in the eastern central Point of Jiaozhou Bay as the source of offshore oil spill, there was a descended PHC content distribution trend from the center to the periphery with the horizontal absolute loss velocity of 0.29-0.45 Yang Dongfang absolute number and the horizontal relative loss velocity of 5.17-8.03 Yang Dongfang relative number. The rising PHC content distribution was consistent with that of the horizontal absolute (relative) loss velocity of PHC content: that of the central water < that of the northwest water < that of the northeast water <that of the southeast water. PHC content indicates the variation amount from the source to certain water, namely terminal value. The horizontal absolute (relative) loss velocity of PHC content indicates the variation process from the source to certain water, namely process value. This reveals that both the terminal value and the process value of PHC content present the migration process of PHC content in waterbody. According to the horizontal velocity model of Yang Dongfang material content, the decreasing and migration process of PHC content toward the periphery along the gradient can be calculated and quantified.

Investigating the hydraulic role of a large buried valley network on regional groundwater flow

An understanding of the three-dimensional hydrostratigraphic architecture of a buried valley network, in particular the continuity of permeable units within their fill, is needed to evaluate the resource potential and role of buried valley aquifers in regional groundwater flow. In this study, a facies modeling algorithm within the exploration and production software Petrel was used to construct a geological model of a buried valley network located in the central Peace Region in Northeast British Columbia, Canada. Facies were interpreted using resistivity inversion results from an airborne electromagnetic survey (SkyTEM) and borehole gamma-ray and lithology logs. This detailed geological model and a simplified geological model of the buried valley network were used to develop two interpretive numerical groundwater flow models in MODFLOW. Calibration was performed using baseflow estimates derived using a novel approach whereby upper and lower bounds for baseflow indices were combined with streamflow estimates from the Northeast Water Tool (NEWT), a hydrological modeling tool developed for water allocation for industrial use by the British Columbia Oil and Gas Commission. The modeling results suggest that permeable deposits exist within the buried valleys, but are not regionally connected throughout the whole network, and thus do not play a significant role in the regional groundwater flow regime. However, locally extensive permeable deposits occur within the buried valleys and may offer viable water sources for domestic use or to replace existing surface-water licenses for industrial use.

Geochemistry of calcite-precipitating waters of the European Northeast

The geochemistry of natural calcite-precipitating waters of the European northeast was presented in this paper. The chemical composition and main hydro-chemical type of these surface and underground waters are various, TDS from 239 to 2090 mg/L. The waters are supersaturated with respect to calcite, there are favorable hydrochemical conditions for formation recent continental carbonates (calcareous tufa, charophyta, calcareous crusts on macrophytes) in the conditions of moderate continental climate.

A Water Allocation Decision‐Support Model and Tool for Predictions in Ungauged Basins in Northeast British Columbia, Canada

AbstractPressures on water resources due to changing climate, increasing demands, and enhanced recognition of environmental flow needs result in the need for hydrology information to support informed water allocation decisions. However, the absence of hydrometric measurements and limited access to hydrology information in many areas impairs water allocation decision‐making. This paper describes a water balance‐based modeling approach and an innovative web‐based decision‐support hydrology tool developed to address this need. Using high‐resolution climate, vegetation, and watershed data, a simple gridded water balance model, adjusted to account for locational variability, was developed and calibrated against gauged watersheds, to model mean annual runoff. Mean monthly runoff was modeled empirically, using multivariate regression. The modeled annual runoff results are within 20% of the observed mean annual discharge for 78% of the calibration watersheds, with a mean absolute error of 16%. Modeled monthly runoff corresponds well to observed monthly runoff, with a median Nash–Sutcliffe statistic of 0.92 and a median Spearman rank correlation statistic of 0.98. Monthly and annual flow estimates produced from the model are incorporated into a map‐ and watershed‐based decision‐support system referred to as the Northeast Water Tool, to provide critical information to decision makers and others on natural water supply, existing allocations, and the needs of the environment.

Arctic Ocean outflow and glacier–ocean interactions modify water over the Wandel Sea shelf (northeastern Greenland)

Abstract. The first-ever conductivity–temperature–depth (CTD) observations on the Wandel Sea shelf in northeastern Greenland were collected in April–May 2015. They were complemented by CTDs taken along the continental slope during the Norwegian FRAM 2014–2015 drift. The CTD profiles are used to reveal the origin of water masses and interactions with ambient water from the continental slope and the tidewater glacier outlet. The subsurface water is associated with the Pacific water outflow from the Arctic Ocean. The underlying halocline separates the Pacific water from a deeper layer of polar water that has interacted with the warm Atlantic water outflow through the Fram Strait, recorded below 140 m. Over the outer shelf, the halocline shows numerous cold density-compensated intrusions indicating lateral interaction with an ambient polar water mass across the continental slope. At the front of the tidewater glacier outlet, colder and turbid water intrusions were observed at the base of the halocline. On the temperature–salinity plots these stations indicate a mixing line that is different from the ambient water and seems to be conditioned by the ocean–glacier interaction. Our observations of Pacific water are set within the context of upstream observations in the Beaufort Sea and downstream observations from the Northeast Water Polynya, and clearly show the modification of Pacific water during its advection across the Arctic Ocean. Moreover, ambient water over the Wandel Sea slope shows different thermohaline structures indicating the different origin and pathways of the on-shore and off-shore branches of the Arctic Ocean outflow through the western Fram Strait.