Marine Chemistry最新文献

{"title":"Examining the utility of barium isotopes as a tracer of large-scale seafloor methane venting","authors":"Ethan Petrou ,&nbsp;Luke Bridgestock ,&nbsp;Germain Bayon ,&nbsp;Nolwenn Lemaitre ,&nbsp;Ya-Zhen Wu ,&nbsp;Gideon M. Henderson ,&nbsp;Yu-Te Hsieh","doi":"10.1016/j.marchem.2026.104608","DOIUrl":"10.1016/j.marchem.2026.104608","url":null,"abstract":"<div><div>Periods of increased sedimentary barium (Ba) burial rates have been interpreted as evidence for climate-driven release of methane (CH₄) from sediments in the geological past, yet such interpretations remain ambiguous. Here, we present the first Ba isotope measurements from an active methane seep to directly evaluate whether Ba isotopes in seawater or authigenic carbonates can record Ba release associated with seafloor methane venting. Dissolved Ba concentration ([Ba]) and isotope composition (δ^138/134Ba) were measured in seawater profiles (1 m to 60 m above the seafloor) and in authigenic carbonates collected across the Regab pockmark on the Congo Margin. Seawater over the active methane venting site shows an increase of around 8% in dissolved [Ba] compared to ambient seawater at the Reference Site, indicating detectable benthic Ba release during methane venting. However, the δ^138/134Ba values of these samples (+0.23‰ to +0.42‰) are indistinguishable from ambient seawater, demonstrating that Ba released during methane venting does not impart a resolvable isotopic shift to the water column. An additional isotopically light Ba input may arise from the dissolution of Fe<img>Mn oxyhydroxide phases at the sediment water interface, but this interpretation is based on a single data point and requires further investigation. Authigenic carbonates at sites of high methane flux exhibit markedly lower δ^138/134Ba values (−0.30‰ to +0.20‰) that are markedly lower than seawater, coral carbonates, and published porewater values, indicating a potential Ba isotope fractionation linked to cold-seep carbonate formation. Overall, these findings suggest that Ba isotopes are unlikely to be a reliable tracer of Ba mobilisation associated with methane venting and challenges the interpretation of sedimentary Ba isotope records as indicators of past large-scale methane release.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"275 ","pages":"Article 104608"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048954","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":"Non-ignorable effect of in situ atmospheric CH4 mole fraction on calculation of diffusive CH4 emission","authors":"Kunpeng Zang ,&nbsp;Dongxia Zhao ,&nbsp;Zengyi Yang ,&nbsp;Xuemei Xu","doi":"10.1016/j.marchem.2026.104620","DOIUrl":"10.1016/j.marchem.2026.104620","url":null,"abstract":"<div><div>CH₄ mole fraction in the marine boundary layer (MBL) is one of important parameters for estimating sea-to-air CH₄ flux, while its influence was lack of quantification. In this work, the impacts of three different atmospheric CH₄ data on the calculated sea-to-air CH₄ flux were evaluated. Results showed that, compared to data observed at the Tae-ahn Peninsula station and the simulated MBL-CH₄ references, in situ observed CH₄ mole fraction in the MBL was 132 and 140 nmol/mol higher in July 2013, and 98 and 132 nmol/mol higher in February 2017 in the Bohai Sea, respectively. Different atmospheric CH₄ mole fraction induced mean deviations of 1.5 μmol/m²/day in July 2013 and 1.0 μmol/m²/day in February 2017, respectively. In addition, effects of three different atmospheric CH₄ mole fractions on sea-to-air CH₄ flux in summer in coastal shallow waters were greater than those in winter in deep open oceans. Thus, to narrow the uncertainty of carbon emission, it was essential to calculate sea-to-air CH₄ flux by using the field observed atmospheric CH₄ mole fraction, especially in coastal shallow seas.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"275 ","pages":"Article 104620"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399974","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":"Comparing methods for measuring 210Po in seawater: Fe(OH)3 can extract less 210Po than Co-APDC and thus overestimate POC export fluxes","authors":"Harold Carrasco ,&nbsp;J. Kirk Cochran ,&nbsp;Beat Gasser ,&nbsp;Inés Sanz-Alvarez ,&nbsp;Montserrat Roca-Martí ,&nbsp;Christina Heilbrun ,&nbsp;Nicholas S. Fisher ,&nbsp;Jana Friedrich ,&nbsp;Pere Masqué","doi":"10.1016/j.marchem.2026.104618","DOIUrl":"10.1016/j.marchem.2026.104618","url":null,"abstract":"<div><div>Over six decades of research, two methods have been used to extract the natural radionuclides ²¹⁰Pb and ²¹⁰Po from seawater- the precipitation of iron hydroxide (Fe(OH)₃) and coagulation of cobalt ammonium pyrrolidine dithiocarbamate (Co-APDC). Although the two methods had been intercompared for ²¹⁰Pb and shown to agree, they were never intercompared for ²¹⁰Po until <span><span>Roca-Martí et al. (2021)</span></span>, in which only unfiltered samples were used. Here we document that Fe(OH)₃ may be less effective in extracting ²¹⁰Po from a seawater sample than Co-APDC. We hypothesize that cycling of ²¹⁰Po through the marine food web can produce a fraction of dissolved ²¹⁰Po complexed with organic ligands and not efficiently precipitated by Fe(OH)₃. We compare the Fe(OH)₃ and Co-APDC methods through field sampling at the DYFAMED site in the Mediterranean Sea and complementary laboratory incubation experiments using phytoplankton. Lower dissolved ²¹⁰Po activities are extracted with Fe(OH)₃ relative to Co-APDC immediately after sampling at times of high primary productivity. No difference between the methods is found for ²¹⁰Pb. Time-series experiments with stored filtered, acidified samples show that Fe(OH)₃ can yield higher activities of ²¹⁰Po after extended storage (∼2 months), approaching values obtained with Co-APDC immediately after sample collection. In laboratory incubation experiments with diatoms and coccolithophores, exudates produced by diatoms show higher ²¹⁰Po activities using the Co-APDC method; no difference between the methods is apparent for coccolithophores. Direct comparison of the methods during a time of high productivity at the DYFAMED site suggests that POC export fluxes based on the Fe(OH)₃ method can be overestimated by ∼50% in the primary productivity zone and by much larger extents in the mesopelagic. Additional field study results from the Northeast Atlantic and Pacific Oceans support these observations. We recommend the Co-APDC method be used for marine studies involving ²¹⁰Po, especially in biologically active waters and if samples are processed soon after collection.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"275 ","pages":"Article 104618"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399976","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":"Molecular composition determines the nitrogen isotopic signatures of dissolved organic matter","authors":"Zhenwei Yan ,&nbsp;Yu Xin ,&nbsp;Yuanbi Yi ,&nbsp;Penghui Li ,&nbsp;Wenqi Xu ,&nbsp;Wanqing Xu ,&nbsp;Youping Zhou ,&nbsp;Chuanlun Zhang ,&nbsp;Ding He","doi":"10.1016/j.marchem.2026.104619","DOIUrl":"10.1016/j.marchem.2026.104619","url":null,"abstract":"<div><div>Marine dissolved organic matter (DOM) represents the largest reduced carbon pool in global carbon cycles. Nitrogen within marine DOM plays a crucial role in linking carbon and nitrogen cycles by serving as both a major nitrogen reservoir and a dynamic source for microbial utilization. Stable nitrogen isotopes (δ¹⁵N) of DOM could provide information about its sources and transformation in marine environments. However, the difficulties and complexities of its measurement leading to a lack of data on DOM's δ¹⁵N, limiting our understandings of marine nitrogen and carbon cycles. In this study, we developed a quick and effective machine learning method for linking δ¹⁵N of solid phase extracted DOM and its molecular composition. 325 samples with molecular composition and δ¹⁵N from China coastal environment are used for modeling, achieving a mean absolute error of 0.32‰. We found that all formulas, even those without nitrogen atoms, have direct or indirect connections with DOM's δ¹⁵N. The developed model not only performs well in China coastal environments, but also show great generalization in other estuaries. Furthermore, our model establishes a connection between δ¹⁵N and molecular composition of marine DOM in coastal ocean, revealing that higher δ¹⁵N values are associated with more saturated and marine-derived DOM, whereas lower δ¹⁵N values tend to be more unsaturated and exhibit terrestrial characteristics. This work elucidates the intrinsic coupling between DOM molecular characteristics and nitrogen isotopic composition, advancing our understanding of nitrogen cycling and organic matter dynamics in marine coastal environments.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"275 ","pages":"Article 104619"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399978","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":"Characterizing organic carbon source, age, and degradation state in Northern Patagonia fjord surface sediments","authors":"Emily G. Watts ,&nbsp;Iván Pérez-Santos ,&nbsp;Jack A. Hutchings ,&nbsp;Derrick R. Vaughn ,&nbsp;Peter A. Raymond ,&nbsp;Andrew R. Zimmerman ,&nbsp;Zhanfei Liu ,&nbsp;Guido Mancilla-Gutiérrez ,&nbsp;Thomas S. Bianchi","doi":"10.1016/j.marchem.2026.104605","DOIUrl":"10.1016/j.marchem.2026.104605","url":null,"abstract":"<div><div>Fjords are a globally significant carbon sink with the highest burial rates of organic carbon (OC) per unit area of all marine depositional systems. As many fjords face the impacts of global change, understanding carbon cycling in these estuaries is crucial. We estimated OC sources and degradation state in Northern Patagonia (41°S to 47°S) fjord sediments using radiocarbon, stable isotopes, and chemical biomarkers. Surface sediment OC content ranged from 0.15 to 5.34%. Majority of this OC was modern, although there was a widespread but low petrogenic OC (OC_petro) content of 0.13, 95% confidence interval [0.08–0.18%]. This OC_petro can be the dominant and even sole source of OC to Northern Patagonia sediments in regions with low overall OC contents. There were steep gradients of modern terrestrial OC (OC_terr) contributions moving from fjords (∼70%) to broader bays and channels (∼6%), indicating these fjords act as OC_terr sinks. There was an apparent decoupling of OC_terr and marine OC (OC_mar) degradation in sediments, reflected by lignin and amino acid biomarkers. This decoupling likely results from the preferential association of OC_mar with minerals, illustrated by high OC_mar to surface area ratios (OC/SA; 0.38 mg C m⁻²) compared to terrestrial OC/SA (0.13 mg C m⁻²), a continuous supply of OC_mar compared to point source inputs of OC_terr, as well as the greater sensitivity of OC_mar to aerobic degradation. Overall, the Northern Patagonia fjord system is a sink of OC_terr, and OC cycling within these fjords will continue to evolve with anthropogenic global change.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"274 ","pages":"Article 104605"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077532","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":"Responses of carbon monoxide photoproduction in surface seawater to environmental changes under simulated solar radiation","authors":"Xuan Ji ,&nbsp;Ming-Liang Zhao ,&nbsp;Yi-Ran Jia ,&nbsp;Cai-Jie Zhang ,&nbsp;Qi-Mei Du ,&nbsp;Jing Zhang ,&nbsp;Gui-Peng Yang","doi":"10.1016/j.marchem.2026.104607","DOIUrl":"10.1016/j.marchem.2026.104607","url":null,"abstract":"<div><div>The ocean is undergoing rapid environmental changes, but how carbon monoxide (CO) photoproduction responds to these changes remains uncertain. Therefore, we used simulated solar radiation to investigate the effects of ocean warming, acidification, deoxygenation, and nitrate concentration changes on CO photoproduction rate in the surface seawater of the Yellow Sea (YS), the East China Sea (ECS), the South China Sea (SCS), and the eastern Indian Ocean (EIO). Ultraviolet radiation contributed more than 90% to CO photoproduction. Dissolved organic matter (DOM) with high aromaticity and abundant humic-like component was an important precursor for CO photoproduction. Under the high-emission scenario, warming is projected to significantly enhance CO photoproduction rate by ∼15% in the terrestrial-influenced regions of the YS and ECS by 2100. In contrast, its effect is projected to be insignificant (an increase of ∼8%) in the oligotrophic SCS and EIO. Moreover, neither a pH reduction of 0.2 or 0.4 units nor deoxygenation are expected to have significant influence on CO photoproduction rate in the study areas. CO photoproduction increases with increasing nitrate concentration, which is attributed to hydroxyl radicals (•OH) produced by nitrate photolysis. The •OH generated by natural seawater photolysis in the investigated areas induced about 10%–23% of CO photoproduction.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"274 ","pages":"Article 104607"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034499","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":"Analysis of nutrient and hydrographic patterns on the GEOTRACES Pacific Meridional Section (GP15) using PYOMPA, a new framework for water mass analysis","authors":"R.M. Lawrence ,&nbsp;A. Shrikumar ,&nbsp;E. Le Roy ,&nbsp;J. Swift ,&nbsp;P.J. Lam ,&nbsp;G.A. Cutter ,&nbsp;K.L. Casciotti","doi":"10.1016/j.marchem.2025.104598","DOIUrl":"10.1016/j.marchem.2025.104598","url":null,"abstract":"<div><div>The GEOTRACES GP15 Pacific Meridional Transect sampled several biogeochemical provinces in the central Pacific Ocean between 56°N and 20°S. This transect was designed to study processes driving the distributions of nutrients, trace elements, and isotopes (TEIs) in the Pacific, including their inputs, losses, and internal cycling. In this study, we report the nutrients (nitrate, nitrite, phosphate, silicate), hydrography (temperature, salinity), and oxygen data for GP15 and quantify how water mass mixing underlies their distributions along GP15 using a modified Optimum Multiparameter Analysis (PYOMPA). By imposing ’soft’ penalties on water mass distributions and using archetype analysis to define endmember properties, results from PYOMPA not only aligned with expectations but yielded lower residuals and allowed us to quantify water mass contributions at regional boundaries with more confidence. The use of flexible regeneration stoichiometry in PYOMPA also highlighted the impacts of regional regeneration and biogeochemical cycling on nutrient distributions along GP15. This analysis informs a better understanding of nutrient transport and regeneration patterns in the central Pacific Ocean, which captures key features of the meridional overturning circulation.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"274 ","pages":"Article 104598"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797427","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":"Effects of mineral inputs on organic phosphorus (Adenosine 5′-monophosphate) sorption and implications for its biogeochemical behavior on marine sediments","authors":"Yu Meng ,&nbsp;Meng Lv ,&nbsp;Xiao-Tong Zhang ,&nbsp;Xiao-Yan Cao ,&nbsp;Rong Chen ,&nbsp;Gui-Peng Yang","doi":"10.1016/j.marchem.2025.104600","DOIUrl":"10.1016/j.marchem.2025.104600","url":null,"abstract":"<div><div>The runoff input of mineral particles in coastal areas affects the migration and transformation of nutrients. Organic phosphorus (OP) has attracted much attention due to coastal eutrophication, while the migration under the influence of mineral inputs has not been understood deeply. This study investigated the sorption behavior of an OP compound (Adenosine 5’-monophosphate, AMP) on goethite, kaolin, and two mixtures of the minerals with natural sediment. Fourier transform infrared spectroscopy (FTIR) spectra and surface acid-base characteristics revealed interactions presented within the mixtures. Sorption kinetics and thermodynamics experiments were carried out through batch methods. The kinetic data were described using a two-compartment first-order equation, and the sorption isotherms were well-fitted by both the Freundlich and Langmuir models. Goethite exhibited a higher sorption ability than kaolin, and the sorption was more sensitive to salinity. The sorption capacity of mineral-added sediments was significantly lower than predicted, particularly for sediments mixed with kaolin, which decreased by 57.4 %. The analysis of OP fractions during sorption revealed an obvious increase in exchangeable or loosely sorbed organic phosphorus (Ex-Po) and iron/aluminium-bound organic phosphorus (NaOH-Po), with NaOH-Po dominating. The sum of Ex-Po and NaOH-Po, as the bioavailable OP, in goethite and kaolin was estimated to be around half of the total sorption amount. Compared to the discrete original ones, the Ex-Po in the sediment with the mineral addition increased while NaOH-Po decreased after sorption, suggesting that the presence of interactions between the minerals and sediment matrix reduced their ability to retain AMP. These findings highlight the significant role of mineral-sediment interactions in altering OP sorption characteristics, with important implications for their biogeochemical fate.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"274 ","pages":"Article 104600"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840687","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":"Do desert dust input and pronounced oxygen minimum zones act as sources or sinks for dissolved molybdenum and uranium? A GEOTRACES study in the eastern Atlantic Ocean","authors":"Sandra Poehle,&nbsp;Imelda B. Velasquez ,&nbsp;Andrea Koschinsky","doi":"10.1016/j.marchem.2025.104580","DOIUrl":"10.1016/j.marchem.2025.104580","url":null,"abstract":"<div><div>Molybdenum (Mo) and uranium (U) are usually considered as conservative metals in the oceanic water column though deviations have been observed in e.g. surface waters. The key objective was to study the impact of dust input and pronounced oxygen minimum zones (OMZs) on dissolved Mo and U in comparison with the truly conservative element rubidium (Rb) in seawater samples from two GEOTRACES research cruises: GA11 - NE-Atlantic affected by Saharan dust and the Mauritanian upwelling and GA08 - SE-Atlantic affected by Namibian dust and the Benguela upwelling.</div><div>We observed slightly higher Mo and U concentrations, 114.8 nmol/kg and 14.5 nmol/kg, respectively, under the Saharan dust plume trajectory (NE-Atlantic) compared to their average seawater concentrations (107 nmol/kg and 13.9 nmol/kg) leading to the assumption of Saharan dust being a source. Slightly lower than average Mo and U concentrations, 102.8 nmol/kg and 11.9 nmol/kg, respectively, above the suboxic Namibian shelf (SE-Atlantic) can be attributed to the formation of reduced solid Mo and U smaller than 0.015 μm. A first hint to a link between sediment-released organic matter and colloidal U requires more research.</div><div>In contrast, Rb concentrations remained constant with depth, unaffected by regional influences in the NE and SE Atlantic, with approx. 1.3 μmol/kg showing truly conservative characteristics.</div><div>Our study implies that the expansion of less oxygenated waters with a potential shift towards euxinic conditions and more extensive dust events in the future due to e.g. climate change may affect the distribution and potentially isotopic signatures of Mo and U.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"274 ","pages":"Article 104580"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692281","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":"The internal consistency between calculated and measured variables of the marine carbonate system in Arctic open and coastal waters, case study: Atlantic Arctic","authors":"Fernando Aguado Gonzalo,&nbsp;Katarzyna Koziorowska,&nbsp;Beata Szymczycha,&nbsp;Karol Kuliński","doi":"10.1016/j.marchem.2026.104604","DOIUrl":"10.1016/j.marchem.2026.104604","url":null,"abstract":"<div><div>The Arctic Ocean plays a crucial role in anthropogenic carbon sequestration, while also being among the regions most susceptible to Ocean Acidification (OA). To understand, quantify, and monitor the rapid biogeochemical changes in the Arctic shelves and coastal waters, it is necessary to accurately determine the complete marine carbonate system. However, the uncertainty range in the calculated values is still unclear, fogging our ability to properly estimate carbon inventory and OA. In this study, we collected samples in the Arctic open and coastal waters to estimate the internal consistency of total alkalinity (TA), pH, partial pressure of CO₂ (pCO₂) and dissolved inorganic carbon (DIC) when only two of them are measured and the other two calculated. In open ocean waters, calculated values generally show good consistency with observations, whereas in coastal areas, it was only possible to accurately calculate two variables: 1) pH using as input parameters pCO₂ together with either TA or DIC, and 2) pCO₂ using DIC and pH. Furthermore, we found that, in this dataset, using the TA estimated from its correlation with salinity together with pCO₂ also allowed obtaining accurate pH values in both coastal and ocean waters. This opens a new possibility of monitoring changes in the carbon cycle by measuring only salinity and pCO₂ in areas where its consistency has been evaluated. Finally, in this study, we provide guidelines for obtaining and reporting good-quality carbonate system data in Arctic coastal areas.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"274 ","pages":"Article 104604"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976560","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}