Marine Chemistry最新文献

{"title":"Regression-based characterization of the marine carbonate system across shelf and nearshore waters of Queen Charlotte Sound","authors":"A.A. Hare ,&nbsp;W. Evans ,&nbsp;H.V. Dosser ,&nbsp;J.M. Jackson ,&nbsp;S.R. Alin ,&nbsp;C. Hannah ,&nbsp;T. Ross ,&nbsp;J.M. Klymak","doi":"10.1016/j.marchem.2025.104511","DOIUrl":"10.1016/j.marchem.2025.104511","url":null,"abstract":"<div><div>Marine carbonate system measurements are essential for understanding ocean acidification and CaCO₃ saturation states, and their response to oceanographic and anthropogenic processes. Acquiring such measurements in remote coastal areas is limited by challenges in the development and deployment of autonomous sensors for these parameters, and by the complexity and costs of directly measuring them. We address this challenge by extending an established method of estimating carbonate system parameters through proxy variables to the remote waters of Queen Charlotte Sound, British Columbia. Paired regressions are developed from bottle samples and common hydrographic measurements for both offshore and coastal waters that intersect in this region but retain distinct relationships between total alkalinity and salinity. Application of these regression models to regional autonomous glider data demonstrates that established features of this shelf system can be characterized from a carbonate system perspective along a contiguous transect from land to the shelf break, despite greater regression uncertainties in coastal water. These results also provide new insight into the dynamics of aragonite saturation on the shelf in relation to regional winds. This approach extends a tool to gain knowledge of the marine carbonate system to a coastal region of the northeast Pacific Ocean where hydrographic data used as proxies are more commonly available.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"270 ","pages":"Article 104511"},"PeriodicalIF":3.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Copper speciation in a tropical mangrove forest of Southeast Asia","authors":"Ying Ping Lee ,&nbsp;Kuo Hong Wong ,&nbsp;Hajime Obata ,&nbsp;Mohd Zaki Kamsah ,&nbsp;Mohd Hisyam Rasidi","doi":"10.1016/j.marchem.2025.104510","DOIUrl":"10.1016/j.marchem.2025.104510","url":null,"abstract":"<div><div>Mangrove forests are vital ecosystems that protect coastlines, sequester carbon, and support diverse food webs. Elucidation of the behaviors of nutrients, trace elements, and organic matters in these regions is crucial to understand the impact of human activities and the potential effects of climate change. In this study, we revealed the distributions and bioavailability of a trace metal, copper (Cu), and conducted the first study of Cu speciation in a mangrove region in Southeast Asia. Dissolved Cu (dCu) concentrations ranged from 0.3 to 2.3 nmol L⁻¹ in the study region, which are relatively low compared to most other coastal regions globally. Two classes of Cu-binding organic ligands with average conditional stability constants, log K, of 15.5 and 13.2, respectively, were detected in mangrove waters. Complexing capacities of the ligands generally decrease in low salinity waters with low dCu concentrations. Concentrations of the stronger-binding class of organic ligand (L₁) were higher than those of dCu, reducing the bioavailable Cu²⁺ concentration to less than femtomolar levels, potentially inducing Cu-limitation to microorganism growth. To further understand the biogeochemical processes of trace metals in mangrove regions, future studies should prioritize obtaining baseline data using standardized sampling and analytical techniques to ensure consistent and reliable results.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"270 ","pages":"Article 104510"},"PeriodicalIF":3.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface macro- and micro-nutrients within the Copper River plume region respond to along-shore winds","authors":"E.L.S. Ortega,&nbsp;I. Reister,&nbsp;S.L. Danielson,&nbsp;A.M. Aguilar-Islas","doi":"10.1016/j.marchem.2025.104508","DOIUrl":"10.1016/j.marchem.2025.104508","url":null,"abstract":"<div><div>The Copper River is a major source of freshwater to the Northern Gulf of Alaska (NGA) shelf with a seasonal cycle that reaches peak discharge in summer. This glacially-fed river also provides a large input of dissolved chemicals to the NGA, and because of its large particle load, it impacts the distribution of particle-reactive elements. Summertime sampling of shelf water properties was carried out within the Copper River plume region during two years: first during a period of upwelling-favorable winds and higher river discharge (4–7 July 2019) and later during lower river discharge and more typical downwelling conditions (11–13 July 2020). Although these wind conditions were observed in separate years, both can occur over the course of a single summer. We found that the export of most nutrients to surface shelf waters was enhanced under upwelling-favorable winds accompanied by higher river discharge compared to downwelling conditions and lower discharge. For example, greater cross-shelf plume transport in 2019 resulted in higher mid-shelf surface inventories for nitrate + nitrite (N + N), silicic acid (H₄SiO₄), phosphate (PO₄³⁻), dissolved Fe (dFe), and dissolved Cu (dCu) compared to 2020. Entrainment of relatively macronutrient-rich subsurface waters under upwelling conditions may also have contributed to the enhancement of these mid-shelf nutrient inventories. The observed high N:P ratios in plume waters were likely driven by the scavenging of P within particle-laden plume waters. Similarly, we observed lower than expected [dFe] (1.58 to 6.12 nM) in particle-laden plume waters, likely a result of enhanced scavenging combined with low concentrations of dissolved Fe-binding ligands. Although dNi and dZn have a river source, we observed lower concentrations in surface shelf waters under upwelling conditions, suggesting enhanced dilution by relatively micronutrient-poor subsurface waters. Results highlight the influence of sub-seasonal variations in atmospheric forcing on nutrient distributions and suggest that this forcing also impacts the location and timing of primary production hotspots during summer, adding to the ecological mosaic of the NGA across a range of temporal and spatial scales.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"270 ","pages":"Article 104508"},"PeriodicalIF":3.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissolved iron release by sediment and dust particles in Antarctic seawater greater than glacial flour and sea-ice particles","authors":"Matthew Corkill ,&nbsp;Klaus Martin Meiners ,&nbsp;Pat Wongpan ,&nbsp;Pier van der Merwe ,&nbsp;Layla Creac'h ,&nbsp;Sandrin Feig ,&nbsp;Talitha Nelson ,&nbsp;Abigail Jessica Rose Smith ,&nbsp;Ashley T. Townsend ,&nbsp;Samantha Twiname ,&nbsp;Delphine Lannuzel","doi":"10.1016/j.marchem.2025.104509","DOIUrl":"10.1016/j.marchem.2025.104509","url":null,"abstract":"<div><div>Primary productivity by phytoplankton in the Southern Ocean can be limited by low iron concentrations. Iron limitation in the surface ocean around Antarctica may be alleviated by particle dissolution of dust from exposed rock, glacial flour, resuspended marine sediment, and sea ice. Ligands, which are ubiquitous in seawater, chelate some metals and keep them in solution. Ligands are thereby thought to increase metal solubility, including iron. Leaching studies of Antarctic particles from various sources are rare but important due to observed and predicted changes occurring around Antarctica, e.g., changes in sea ice and ice-free areas on the continent. Here, we quantified the solubility of iron in different particle types using vertical flow-through leaching experiments that simulated sinking through the water column and ran for 78 min of flow at 4 °C under trace metal-clean conditions. Both unaltered and ultraviolet-irradiated seawater leaching solution treatments were used to test the effect of organic ligands on iron dissolution, which was found to be non-significant. Sediment and dust released the most dissolved iron to seawater, followed by glacial flour, and then sea-ice particles (9.00 ± 9.92 × 10⁻² and 3.18 ± 3.79 × 10⁻², 1.97 ± 1.79 × 10⁻⁴, 1.37 ± 0.90 × 10⁻⁹ g DFe/100 g material, respectively). We discuss these laboratory results in relation to particle availability and how this may affect the supply of dissolved iron to Antarctic surface waters.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"270 ","pages":"Article 104509"},"PeriodicalIF":3.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative study of dissolved copper speciation using DGT and CLE-AdSV in a contaminated urban river estuary and marina","authors":"Billie G.B. Benedict ,&nbsp;Rebecca Zitoun ,&nbsp;Keith A. Hunter ,&nbsp;Sylvia G. Sander","doi":"10.1016/j.marchem.2025.104500","DOIUrl":"10.1016/j.marchem.2025.104500","url":null,"abstract":"<div><div>A comprehensive study was conducted in a river estuary and marina in Auckland, New Zealand, to examine the <em>in-situ</em> speciation of copper (Cu) complexes across freshwater, estuarine, and marine environments using the diffusive gradient in thin films (DGT) technique. The study employed both open-pore (OP) and restrictive-pore (RP) diffusive gels of varying thicknesses to assess the effectiveness of DGT hydrogels and the role of the apparent diffusive boundary layer (ADBL) in determining the lability of Cu complexes in natural waters. The DGT findings were compared with results from competing ligand exchange–adsorptive stripping voltammetry (CLE-AdSV) and a speciation prediction model (WHAM/Model-VII). The study highlighted the critical importance of accounting for the ADBL, as its exclusion led to an average underestimation of Cu-complex lability by approximately 50 %. Given the minimal difference in outcomes between DGT-OP and DGT-RP, the use of standard DGT-OP is recommended. Further analysis revealed a strong correlation between DGT-labile Cu (CuDGT-lab), the weaker Cu-L₂ complexes detected by CLE-AdSV, and the inorganic Cu species predicted by WHAM/Model-VII, the latter two based on discrete samples. A strong relationship was also noted between Cu_DGT-lab and the inorganic Cu measured by CLE-AdSV. The study provided compelling evidence that the <em>in-situ</em> ligand pool consists of a mixture of terrestrial humic substances and marine-derived organic ligands. These marine ligands form highly stable Cu-L₁ complexes along the salinity gradient, which were mostly DGT-inert. The DGT results indicated that the lability of <em>in-situ</em> Cu complexes decreased with increasing salinity, with over 60 % of Cu in freshwater being DGT-labile. Overall, the study demonstrates that the DGT technique is a robust and straightforward method for environmental monitoring and risk assessment across diverse physico-chemical water conditions.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"270 ","pages":"Article 104500"},"PeriodicalIF":3.0,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Excess alkalinity and its impacts on pCO2 estimation in coastal and estuarine waters of the Yellow Sea","authors":"Young Ho Ko ,&nbsp;Seung-Hee Shin ,&nbsp;Seong-Gil Kim ,&nbsp;Mi-Ok Park ,&nbsp;Min-Woo Seok ,&nbsp;Min-Soo Kim ,&nbsp;Kitack Lee ,&nbsp;Tae-Wook Kim","doi":"10.1016/j.marchem.2025.104499","DOIUrl":"10.1016/j.marchem.2025.104499","url":null,"abstract":"<div><div>Excess alkalinity (TA_EX) represents an uncharacterized component of total alkalinity (TA), which can introduce significant uncertainty in the estimation of other carbonate parameters. This effect is particularly pronounced in productive coastal regions, where the use of measured TA as an input parameter may lead to inaccurate assessment. In this study, we evaluated the seasonal variability of TA_EX along the western coast of South Korea by applying an overdetermination method, which allows for the quantification of discrepancies (i.e., TA_EX) between measured TA and values calculated from pH and dissolved inorganic carbon (DIC). Samples with salinity below 20 were excluded due to difficulties in accurately quantifying uncertainties in TA_EX calculations, which increase significantly below this threshold. Elevated TA_EX concentrations were found in waters with salinity below 25, with some instances exhibiting TA_EX values reaching up to 50 μmol kg⁻¹, suggesting riverine influence. Additionally, elevated TA_EX values (&gt; 20 μmol kg⁻¹) were also observed in locations markedly undersaturated with respect to atmospheric CO₂, indicating contributions from in-situ biological production. The high TA_EX values associated with increased water transparency during autumn and winter months suggested that light penetration may significantly enhance biological activity, subsequently increasing TA_EX levels. These findings highlight the importance of riverine inputs and biological processes in shaping the spatial and temporal distribution of TA_EX. In the study area, TA_EX should be accounted for in seawater partial pressure of CO₂ (<em>p</em>CO₂) calculations using the DIC–TA pair, as TA_EX significantly influences these calculations compared to the pH–TA and pH–DIC pair.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"269 ","pages":"Article 104499"},"PeriodicalIF":3.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving measurement comparability in mercury speciation analysis in seawater: Key requirements and best practices","authors":"Igor Živković ,&nbsp;Lars-Eric Heimbürger-Boavida ,&nbsp;Mariia V. Petrova ,&nbsp;Aurélie Dufour ,&nbsp;Ermira Begu ,&nbsp;Milena Horvat","doi":"10.1016/j.marchem.2025.104498","DOIUrl":"10.1016/j.marchem.2025.104498","url":null,"abstract":"<div><div>The comparability of measurement results is an important issue in contemporary mercury (Hg) speciation in seawater. Sampling campaigns must be properly designed to determine significant differences on spatial and temporal scales, considering two major parameters: the variability of expected data at a given sampling point/transect and variability in the results due to the intrinsic properties of specific analytical methods, particularly the measurement uncertainty. This study assessed the required sample size, considering several aspects of data variability when determining total Hg, dissolved gaseous Hg, and methylated Hg species in seawater. The required sample sizes were calculated using (1) the measurement uncertainty of a single-laboratory measurement of analytical methods used; (2) performance of the laboratories in interlaboratory comparison exercises; and (3) natural variability in Hg species/fractions in a selected case study in the Central Adriatic Sea. It was shown that the measurement uncertainty of a particular method and interlaboratory variability among laboratories have significant influence on data interpretation in case natural variability of Hg fractions is relatively small, such as for example the open seawater depth profiles. In contrary, in areas with large natural variability of Hg contractions, such as coastal and contaminated sites, their influence on data interpretation is negligible. The present paper introduces the importance of proper estimation of measurement uncertainty in international programs, such as GEOTRACES, where data comparability is of fundamental importance to assess temporal and spatial trends of Hg measurements in the marine environment.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"269 ","pages":"Article 104498"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical-biological processes regulating summer sea-air CO2 exchanges along the Drake Passage and northern Antarctic Peninsula","authors":"Rodrigo Kerr ,&nbsp;Thiago Monteiro ,&nbsp;Matheus S. Batista ,&nbsp;Brendon Yuri Damini","doi":"10.1016/j.marchem.2025.104497","DOIUrl":"10.1016/j.marchem.2025.104497","url":null,"abstract":"<div><div>We determined the sea-air carbon dioxide (CO₂) exchanges and investigated the main physical-biological processes responsible for regulating the sea surface partial pressure of CO₂. This was done through the analysis of continuous and discrete measurements of oceanographic and atmospheric variables measured during the NAUTILUS V cruise (January 2019) crossing the main fronts along the Drake Passage and several distinct biogeochemical provinces along the northern Antarctic Peninsula. The main findings indicated that the Drake Passage acted as a weak net CO₂ outgassing area (∼0.1 mmol m⁻² d⁻¹), although contrasting regions with close sea-air CO₂ fluxes magnitudes of ∼3 mmol m⁻² d⁻¹ were identified north (a net CO₂ sink zone regulated by net photosynthesis) and south (a net CO₂ source zone regulated by net respiration) of the Polar Front. On the other hand, the northern Antarctic Peninsula areas demonstrated a more heterogeneous sea-air CO₂ exchanges behaviour varying from moderate net CO₂ outgassing of ∼1.3 mmol m⁻² d⁻¹ (Bransfield Strait, western Antarctic Peninsula and Weddell Sea continental shelves) to a moderate (∼ −2.4 mmol m⁻² d⁻¹) or weak (∼ −0.1 mmol m⁻² d⁻¹) net CO₂ ingassing in Antarctic Sound surroundings and Gerlache Strait, respectively. It is interesting to note that a huge intensification of the net CO₂ outgassing of ∼5 mmol m⁻² d⁻¹ was identified in the area under the influence of the Antarctic Slope Front bifurcation eddy south of Clarence Island. The CO₂ outgassing is expected in this stationary and anticyclonic feature, but its magnitude was ∼75 % higher than the known estimate, which was associated with strengthen winds and eddy dynamics. Net respiration was the leading biological process occurring in the study area, except north of Polar Front where net photosynthesis prevailed. The patchy distribution of sea-air CO₂ exchanges behaviour along the Drake Passage and northern Antarctic Peninsula reinforced the needs for better understanding and focus on finer resolution of the CO₂ chemistry and processes at regional and local investigations, especially in a region suffering with multiple climate stressors, located in a transition zone of warm and cold environments, and key to connect the Southern Ocean ecosystems in a circumpolar way.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"269 ","pages":"Article 104497"},"PeriodicalIF":3.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143222704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical biochemical composition of particulate organic matter in the Seychelles-Chagos Thermocline Ridge (SCTR), southwestern Indian Ocean","authors":"Sanghoon Park ,&nbsp;Yejin Kim ,&nbsp;Jaesoon Kim ,&nbsp;Jae Ha Jeon ,&nbsp;Inhee Lee ,&nbsp;Doshik Hahm ,&nbsp;Dong-Jin Kang ,&nbsp;Sang Heon Lee","doi":"10.1016/j.marchem.2025.104496","DOIUrl":"10.1016/j.marchem.2025.104496","url":null,"abstract":"<div><div>The Seychelles-Chagos Thermocline Ridge (SCTR) in the southwestern Indian Ocean is characterized by upwelling-driven nutrient enrichment and enhanced biological activity compared to adjacent non-SCTR regions. This study investigated the vertical distribution and biochemical composition of particulate organic matter (POM) within these contrasting environments. The SCTR featured a shallower thermocline and cooler sea surface temperatures, indicative of upwelling, which correlated with significantly higher chlorophyll-<em>a</em> concentrations (<em>t</em>-test, <em>p</em> &lt; 0.05). A notable dominance of micro-sized phytoplankton was observed in the SCTR, contributing 13.6 ± 3.0 % of the total phytoplankton biomass, compared to 5.6 ± 1.6 % in the non-SCTR. CHEMTAX analysis revealed distinct phytoplankton communities, with diatoms being approximately four times more abundant in the SCTR (16.5 ± 4.5 %) than in the non-SCTR (4.2 ± 1.2 %). Meanwhile, <em>Prochlorococcus</em> dominated both regions but contributed less in the SCTR (25.2 ± 3.9 %) than non-SCTR (46.8 ± 7.1 %). The biological macromolecular composition of POM showed clear regional differences, with lipid concentrations in the SCTR's photic layer significantly higher (61.3 μg L⁻¹) than in the non-SCTR (23.4 μg L⁻¹). Total biological macromolecule concentrations in the SCTR's photic zone was more than double that of the non-SCTR (96.3 μg L⁻¹ vs. 40.9 μg L⁻¹), reflecting enhanced biological productivity. Elevated macromolecule concentrations were also detected in the aphotic layer of the SCTR. Notably, the less pronounced decline in the protein-to-carbohydrate ratio from photic to aphotic layers in the SCTR suggests that POM sinking to the deep ocean in this region is relatively fresher and less degraded, indicating a more efficient biological carbon pump and enhanced potential for carbon sequestration. These findings highlight the SCTR as a key region of elevated biological productivity and distinct environmental mechanisms driving biogeochemical cycling, providing critical insights into organic matter preservation and carbon export processes in tropical upwelling systems and their role in global marine ecosystems.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"269 ","pages":"Article 104496"},"PeriodicalIF":3.0,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the Mackenzie River plume dispersal on the dissolved barium concentrations in the upper Canada Basin waters","authors":"M. Gamrani ,&nbsp;S. Zimmermann ,&nbsp;W.J. Williams ,&nbsp;C. Guéguen","doi":"10.1016/j.marchem.2025.104495","DOIUrl":"10.1016/j.marchem.2025.104495","url":null,"abstract":"<div><div>Dissolved barium has been shown to have the potential to track river runoff in marine waters. In this study, the distribution of dissolved barium was determined in the upper 450 m waters of the Canada Basin along the Joint Ocean Ice Study 140°W transect in August/September 2019–2021. In these highly stratified Canada Basin waters, the dBa concentrations increased from 42.51 nmol kg⁻¹ in the Atlantic waters to 128.91 nmol kg⁻¹ in the polar mixed layer. The dispersal of Ba-rich surface waters found over the slope and outer shelves is attributed to the Mackenzie River plume. These waters were either confined nearshore with northwest winds (2019 and 2020) or entrained into the Beaufort Gyre interior under easterly winds (2021). In the subsurface layers, the vertical variation in barium concentration in the Pacific Winter Water and Atlantic Halocline waters showed evidence of mixing. Dissolved Ba dynamics provide a window into the complex interplay between physical, biological, and chemical processes in Arctic waters, making it a valuable tracer for understanding ocean circulation, nutrient transport, and ecosystem functioning in the rapidly changing Arctic region.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"269 ","pages":"Article 104495"},"PeriodicalIF":3.0,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}