Peng Ren , Claude Hillaire-Marcel , Mengmeng Wang , Sen Shan , Song Zhao , Tengfei Song , Linsen Dong , Xuchen Wang , Yanguang Liu
{"title":"北冰洋楚科奇海陆相有机碳的来源、运输、年龄和演化","authors":"Peng Ren , Claude Hillaire-Marcel , Mengmeng Wang , Sen Shan , Song Zhao , Tengfei Song , Linsen Dong , Xuchen Wang , Yanguang Liu","doi":"10.1016/j.gloplacha.2025.104978","DOIUrl":null,"url":null,"abstract":"<div><div>Global warming and permafrost thawing are expected to release substantial amounts of organic carbon (OC) into the Arctic Ocean, potentially intensifying climate warming through a positive feedback loop. In our study, we investigated the sources, transport, and evolution of terrestrial OC (terr-OC) across the Chukchi Sea margin in the Arctic Ocean, using carbon isotope (<sup>13</sup>C and <sup>14</sup>C) and biomarker (<em>n</em>-alkanes and lignin) analyses. Our findings revealed that terr-OC from various sources, such as Ice Complex Deposits (ICD), topsoil, and high plants, was stored and evolved across the Chukchi continental marginal seas. A dual‑carbon-isotope mixing model indicated that ICD was the dominant terr-OC source (47 ± 21 %) in sediments, with its contribution increasing from the Chukchi shelf to the slope. While, the proportion of topsoil-OC (18 ± 7 %) decreased with distance and over time along the Chukchi slope. The enriched Δ<sup>14</sup>C values and higher molecular degradation proxies on the Chukchi shelf suggested that a large proportion of the exogenous terr-OC had undergone significant degradation before reaching the sediment-water interface. During transport, selective degradation occurred, with lignin and <em>n</em>-alkanes declining faster than TOC, and topsoil-OC degrading rapidly than ICD-OC. This prolonged transport likely intensified selective degradation, as changes in terr-OC across the Chukchi shelf to slope were more noticeable than in vertical sediment core profiles. This study emphasizes the Arctic Ocean as a critical sink for diverse forms of terr-OC and highlights the importance of lateral transport, deposition, and degradation in OC burial processes. Further research on precise temporal scales is needed to clarify whether the observed spatial differences stem from variations in sediment sources or from the combined effects of hydrodynamic sorting and selective degradation during lateral transport.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104978"},"PeriodicalIF":4.0000,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Sources, transport, age, and evolution of terrestrial organic carbon across the Chukchi Sea margin, Arctic Ocean\",\"authors\":\"Peng Ren , Claude Hillaire-Marcel , Mengmeng Wang , Sen Shan , Song Zhao , Tengfei Song , Linsen Dong , Xuchen Wang , Yanguang Liu\",\"doi\":\"10.1016/j.gloplacha.2025.104978\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Global warming and permafrost thawing are expected to release substantial amounts of organic carbon (OC) into the Arctic Ocean, potentially intensifying climate warming through a positive feedback loop. In our study, we investigated the sources, transport, and evolution of terrestrial OC (terr-OC) across the Chukchi Sea margin in the Arctic Ocean, using carbon isotope (<sup>13</sup>C and <sup>14</sup>C) and biomarker (<em>n</em>-alkanes and lignin) analyses. Our findings revealed that terr-OC from various sources, such as Ice Complex Deposits (ICD), topsoil, and high plants, was stored and evolved across the Chukchi continental marginal seas. A dual‑carbon-isotope mixing model indicated that ICD was the dominant terr-OC source (47 ± 21 %) in sediments, with its contribution increasing from the Chukchi shelf to the slope. While, the proportion of topsoil-OC (18 ± 7 %) decreased with distance and over time along the Chukchi slope. The enriched Δ<sup>14</sup>C values and higher molecular degradation proxies on the Chukchi shelf suggested that a large proportion of the exogenous terr-OC had undergone significant degradation before reaching the sediment-water interface. During transport, selective degradation occurred, with lignin and <em>n</em>-alkanes declining faster than TOC, and topsoil-OC degrading rapidly than ICD-OC. This prolonged transport likely intensified selective degradation, as changes in terr-OC across the Chukchi shelf to slope were more noticeable than in vertical sediment core profiles. This study emphasizes the Arctic Ocean as a critical sink for diverse forms of terr-OC and highlights the importance of lateral transport, deposition, and degradation in OC burial processes. Further research on precise temporal scales is needed to clarify whether the observed spatial differences stem from variations in sediment sources or from the combined effects of hydrodynamic sorting and selective degradation during lateral transport.</div></div>\",\"PeriodicalId\":55089,\"journal\":{\"name\":\"Global and Planetary Change\",\"volume\":\"253 \",\"pages\":\"Article 104978\"},\"PeriodicalIF\":4.0000,\"publicationDate\":\"2025-07-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Global and Planetary Change\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0921818125002875\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOGRAPHY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Global and Planetary Change","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921818125002875","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}
Sources, transport, age, and evolution of terrestrial organic carbon across the Chukchi Sea margin, Arctic Ocean
Global warming and permafrost thawing are expected to release substantial amounts of organic carbon (OC) into the Arctic Ocean, potentially intensifying climate warming through a positive feedback loop. In our study, we investigated the sources, transport, and evolution of terrestrial OC (terr-OC) across the Chukchi Sea margin in the Arctic Ocean, using carbon isotope (13C and 14C) and biomarker (n-alkanes and lignin) analyses. Our findings revealed that terr-OC from various sources, such as Ice Complex Deposits (ICD), topsoil, and high plants, was stored and evolved across the Chukchi continental marginal seas. A dual‑carbon-isotope mixing model indicated that ICD was the dominant terr-OC source (47 ± 21 %) in sediments, with its contribution increasing from the Chukchi shelf to the slope. While, the proportion of topsoil-OC (18 ± 7 %) decreased with distance and over time along the Chukchi slope. The enriched Δ14C values and higher molecular degradation proxies on the Chukchi shelf suggested that a large proportion of the exogenous terr-OC had undergone significant degradation before reaching the sediment-water interface. During transport, selective degradation occurred, with lignin and n-alkanes declining faster than TOC, and topsoil-OC degrading rapidly than ICD-OC. This prolonged transport likely intensified selective degradation, as changes in terr-OC across the Chukchi shelf to slope were more noticeable than in vertical sediment core profiles. This study emphasizes the Arctic Ocean as a critical sink for diverse forms of terr-OC and highlights the importance of lateral transport, deposition, and degradation in OC burial processes. Further research on precise temporal scales is needed to clarify whether the observed spatial differences stem from variations in sediment sources or from the combined effects of hydrodynamic sorting and selective degradation during lateral transport.
期刊介绍:
The objective of the journal Global and Planetary Change is to provide a multi-disciplinary overview of the processes taking place in the Earth System and involved in planetary change over time. The journal focuses on records of the past and current state of the earth system, and future scenarios , and their link to global environmental change. Regional or process-oriented studies are welcome if they discuss global implications. Topics include, but are not limited to, changes in the dynamics and composition of the atmosphere, oceans and cryosphere, as well as climate change, sea level variation, observations/modelling of Earth processes from deep to (near-)surface and their coupling, global ecology, biogeography and the resilience/thresholds in ecosystems.
Key criteria for the consideration of manuscripts are (a) the relevance for the global scientific community and/or (b) the wider implications for global scale problems, preferably combined with (c) having a significance beyond a single discipline. A clear focus on key processes associated with planetary scale change is strongly encouraged.
Manuscripts can be submitted as either research contributions or as a review article. Every effort should be made towards the presentation of research outcomes in an understandable way for a broad readership.