Global Biogeochemical Cycles最新文献

{"title":"Organic Coatings Reduce Dissolution Rate by an Order of Magnitude for Carbonate Minerals Produced by Marine Fish","authors":"Amanda M. Oehlert,&nbsp;Sarah Walls,&nbsp;Katelyn Arista,&nbsp;Jazmin Garza,&nbsp;Erik J. Folkerts,&nbsp;Brooke E. Vitek,&nbsp;Sadegh Tale Masoule,&nbsp;Clément G. L. Pollier,&nbsp;Gaëlle Duchâtellier,&nbsp;John D. Stieglitz,&nbsp;Daniel D. Benetti,&nbsp;Rachael M. Heuer,&nbsp;Ali Ghahremaninezhad,&nbsp;Martin Grosell","doi":"10.1029/2024GB008176","DOIUrl":"https://doi.org/10.1029/2024GB008176","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Marine carbonate production and dissolution are important components of the global carbon cycle and the marine alkalinity budget. Global carbonate production by marine fish (ichthyocarbonate) has been estimated to be as high as 9.03 Pg CaCO₃ yr⁻¹; however, the fate of ichthyocarbonate is poorly understood. High magnesium concentrations in ichthyocarbonate would traditionally suggest rapid dissolution under current marine conditions, but a correlation between dissolution rate and mol%MgCO₃ has not been observed. Here, we aim to determine the role of organic coatings on dissolution rates of ichthyocarbonate in marine environments. We applied a combination of petrographic, geochemical, and microCT approaches to assess the quantity and distribution of organic matter in ichthyocarbonate produced by two species of marine fish, the Gulf toadfish (<i>Opsanus beta</i>) and the Olive flounder (<i>Paralichthys olivaceus</i>). We show that organic matter, including external coatings and embedded organic material, is volumetrically significant, ranging from 8.5% to 32.3% of ichthyocarbonate by volume. Bleach oxidation of external organic matter coatings increased the dissolution rate of ichthyocarbonate by more than an order of magnitude, suggesting these coatings serve to reduce reactive surface area of the mineral fraction in ichthyocarbonate. Assuming that organic coatings do not influence sinking rates, external coatings extend the depth of ichthyocarbonate persistence in the water column by ∼12–15×. Therefore, organic coatings are an important determinant of the role of ichthyocarbonate in the marine carbon cycle.</p>\u0000 </section>\u0000 </div>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"38 11","pages":""},"PeriodicalIF":5.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GB008176","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Macroecology Differentiation Between Bacteria and Fungi in Topsoil Across the United States","authors":"Liyuan He,&nbsp;Nicolas Viovy,&nbsp;Xiaofeng Xu","doi":"10.1029/2023GB007706","DOIUrl":"https://doi.org/10.1029/2023GB007706","url":null,"abstract":"<p>Bacteria and fungi possess distinct physiological traits. Their macroecology is vital for ecosystem functioning such as carbon cycling. However, bacterial and fungal biogeography and underlying mechanisms remain elusive. In this study, we investigated bacterial versus fungal macroecology by integrating a microbial-explicit model—CLM-Microbe—with measured fungal (FBC) and bacterial biomass carbon (BBC) from 34 NEON sites. The distribution of FBC, BBC, and FBC: BBC (F:B) ratio was well simulated across sites, with variations in 99% (<i>P</i> &lt; 0.001), 97% (<i>P</i> &lt; 0.001), and 99% (<i>P</i> &lt; 0.001) being explained by the CLM-Microbe model, respectively. We found stronger biogeographic patterns of FBC relative to BBC across the United States. Fungal and bacterial turnover rates showed similar trends along latitude. However, latitudinal trends of their component fluxes (carbon assimilation, respiration, and necromass production) were distinct between bacteria and fungi, with those latitudinal trends following inverse unimodal patterns for fungi and showing exponential declining responses for bacteria. Carbon assimilation was dominated by vegetation productivity, and respiration was dominated by mean annual temperature for bacteria and fungi. The dominant factor for their necromass production differs, with edaphic factors controlling fungal and mean annual temperature controlling bacterial processes. The understanding of fungal and bacterial macroecology is an important step toward linking microbial metabolism and soil biogeochemical processes. Distinct fungal and bacterial macroecology contributes to the microbial ecology, particularly on microbial community structure and its association with ecosystem carbon cycling across space.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 11","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GB007706","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68181324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Shifts in the Isotopic Composition of Nitrous Oxide Between El Niño and La Niña in the Eastern Tropical South Pacific","authors":"Noah Gluschankoff,&nbsp;Alyson E. Santoro,&nbsp;Carolyn Buchwald,&nbsp;Karen L. Casciotti","doi":"10.1029/2023GB007959","DOIUrl":"https://doi.org/10.1029/2023GB007959","url":null,"abstract":"<p>The El Niño-Southern Oscillation (ENSO) is a natural climate phenomenon that alters the biogeochemical and physical dynamics of the Eastern Tropical Pacific Ocean. Its two phases, El Niño and La Niña, are characterized by decreased and increased coastal upwelling, respectively, which have cascading effects on primary productivity, organic matter supply, and ocean-atmosphere interactions. The Eastern Tropical South Pacific oxygen minimum zone is a source of nitrous oxide (N₂O), a potent greenhouse gas, to the atmosphere. Here, we present the first study to directly compare N₂O sources during opposing ENSO phases using N₂O isotopocule analyses. Our data show that during La Niña, N₂O accumulation increased six-fold in the upper 100 m of the water column, and N₂O fluxes to the atmosphere increased up to 20-fold. N₂O isotopocule data demonstrated substantial increases in δ¹⁸O up to 60.5‰ and decreases in δ¹⁵N^<i>β</i> down to −10.3‰ in the oxycline, signaling a shift in N₂O cycling during La Niña compared to El Niño. During El Niño, N₂O production was primarily due to ammonia-oxidizing archaea, whereas during La Niña, N₂O production by incomplete denitrification supplemented that from ammonia-oxidation, with N₂O consumption likely maintaining the high site preference values (up to 26.7‰). Ultimately, our results illustrate a strong connection between upwelling intensity, biogeochemistry, and N₂O flux to the atmosphere. Additionally, they highlight the combined power of N₂O isotopocule analysis and repeat measurements in the same region to constrain N₂O interannual variability and cycling dynamics under different climate scenarios.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50147092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Nitrogen Mass Flux From the Active Freshwater Aquifer Element Pool","authors":"Warren W. Wood,&nbsp;Ward E. Sanford,&nbsp;John A. Cherry,&nbsp;David W. Hyndman,&nbsp;Warren T. Wood","doi":"10.1029/2023GB007878","DOIUrl":"https://doi.org/10.1029/2023GB007878","url":null,"abstract":"<p>The estimated current global mean nitrogen concentration (geogenic + anthropogenic) in the active continental freshwater aquifer element pool is 1.1 mg/L as N, or between four and five times greater than the assumed geogenic mean. This concentration, combined with groundwater flux, generates a continental mass flux of 17 Tg N/y (teragrams of nitrogen, as N, per year) as a result of direct ocean discharge (0.67 Tg N/y), endorheic basins (1.2 Tg N/y), and cold-wet (0.82 Tg N/y); cold-dry (1.4 Tg N/y); warm-dry (1.6 Tg N/y); and warm-wet (11 Tg N/y) exorheic basins. These values are derived from a geospatial machine learning algorithm and combined groundwater-modeled recharge in an ArcGIS environment. This active continental freshwater aquifer mass flux is between 35% and 40% of the continental integrated riverine system discharge, thus a significant component of the Earth's active continental freshwater nitrogen budget. We estimate the active continental freshwater aquifer volume to be between 1.4 and 2.8 million km³ suggesting a legacy of between 1.5 and 3.1 Pg as N (petagrams nitrogen as N) with mean residences of 90–180 years.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GB007878","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50137339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Increased Terrestrial Carbon Export and CO2 Evasion From Global Inland Waters Since the Preindustrial Era","authors":"Hanqin Tian,&nbsp;Yuanzhi Yao,&nbsp;Ya Li,&nbsp;Hao Shi,&nbsp;Shufen Pan,&nbsp;Raymond G. Najjar,&nbsp;Naiqing Pan,&nbsp;Zihao Bian,&nbsp;Philippe Ciais,&nbsp;Wei-Jun Cai,&nbsp;Minhan Dai,&nbsp;Marjorie A. M. Friedrichs,&nbsp;Hong-Yi Li,&nbsp;Steven Lohrenz,&nbsp;L. Ruby Leung","doi":"10.1029/2023GB007776","DOIUrl":"https://doi.org/10.1029/2023GB007776","url":null,"abstract":"<p>Global carbon dioxide (CO₂) evasion from inland waters (rivers, lakes, and reservoirs) and carbon (C) export from land to oceans constitute critical terms in the global C budget. However, the magnitudes, spatiotemporal patterns, and underlying mechanisms of these fluxes are poorly constrained. Here, we used a coupled terrestrial–aquatic model to assess how multiple changes in climate, land use, atmospheric CO₂ concentration, nitrogen (N) deposition, N fertilizer and manure applications have affected global CO₂ evasion and riverine C export along the terrestrial-aquatic continuum. We estimate that terrestrial C loadings, riverine C export, and CO₂ evasion in the preindustrial period (1800s) were 1,820 ± 507 (mean ± standard deviation), 765 ± 132, and 841 ± 190 Tg C yr⁻¹, respectively. During 1800–2019, multifactorial global changes caused an increase of 25% (461 Tg C yr⁻¹) in terrestrial C loadings, reaching 2,281 Tg C yr⁻¹ in the 2010s, with 23% (104 Tg C yr⁻¹) of this increase exported to the ocean and 59% (273 Tg C yr⁻¹) being emitted to the atmosphere. Our results showed that global inland water recycles and exports nearly half of the net land C sink into the atmosphere and oceans, highlighting the important role of inland waters in the global C balance, an amount that should be taken into account in future C budgets. Our analysis supports the view that a major feature of the global C cycle–the transfer from land to ocean–has undergone a dramatic change over the last two centuries as a result of human activities.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GB007776","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50131927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"A Spatial Assessment of Current and Future Foliar Hg Uptake Fluxes Across European Forests","authors":"Lena Wohlgemuth,&nbsp;Aryeh Feinberg,&nbsp;Allan Buras,&nbsp;Martin Jiskra","doi":"10.1029/2023GB007833","DOIUrl":"https://doi.org/10.1029/2023GB007833","url":null,"abstract":"<p>Atmospheric mercury (Hg) is deposited to land surfaces mainly through vegetation uptake. Foliage stomatal gas exchange plays an important role for net vegetation Hg uptake, because foliage assimilates Hg via the stomata. Here, we use empirical relationships of foliar Hg uptake by forest tree species to produce a spatially highly resolved (1 km²) map of foliar Hg fluxes to European forests over one growing season. The modeled forest foliar Hg uptake flux is 23 ± 12 Mg Hg season⁻¹, which agrees with previous estimates from literature. We spatially compared forest Hg fluxes with modeled fluxes of the chemical transport model GEOS-Chem and find a good overall agreement. For European pine forests, stomatal Hg uptake was shown to be sensitive to prevailing conditions of relatively high ambient water vapor pressure deficit (VPD). We tested a stomatal uptake model for the total pine needle Hg uptake flux during four previous growing seasons (1994, 2003, 2015/2017, 2018) and two climate change scenarios (RCP 4.5 and RCP 8.5). The resulting modeled total European pine needle Hg uptake fluxes are in a range of 8.0–9.3 Mg Hg season⁻¹ (min–max). The lowest pine forest needle Hg uptake flux to Europe (8 Mg Hg season⁻¹) among all investigated growing seasons was associated with unusually hot and dry ambient conditions in the European summer 2018, highlighting the sensitivity of the investigated flux to prolonged high VPD. We conclude, that stomatal modeling is particularly useful to investigate changes in Hg deposition in the context of extreme climate events.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GB007833","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50147078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Seasonal Tropospheric Distribution and Air-Sea Fluxes of Atmospheric Potential Oxygen From Global Airborne Observations","authors":"Yuming Jin,&nbsp;Britton B. Stephens,&nbsp;Ralph F. Keeling,&nbsp;Eric J. Morgan,&nbsp;Christian Rödenbeck,&nbsp;Prabir K. Patra,&nbsp;Matthew C. Long","doi":"10.1029/2023GB007827","DOIUrl":"https://doi.org/10.1029/2023GB007827","url":null,"abstract":"<p>Seasonal change of atmospheric potential oxygen (APO ∼ O₂ + CO₂) is a tracer for air-sea O₂ flux with little sensitivity to the terrestrial exchange of O₂ and CO₂. In this study, we present the tropospheric distribution and inventory of APO in each hemisphere with seasonal resolution, using O₂ and CO₂ measurements from discrete airborne campaigns between 2009 and 2018. The airborne data are represented on a mass-weighted isentropic coordinate (<i>M</i>_<i>θe</i>) as an alternative to latitude, which reduces the noise from synoptic variability in the APO cycles. We find a larger seasonal amplitude of APO inventory in the Southern Hemisphere relative to the Northern Hemisphere, and a larger amplitude in high latitudes (low <i>M</i>_<i>θe</i>) relative to low latitudes (high <i>M</i>_<i>θe</i>) within each hemisphere. With a box model, we invert the seasonal changes in APO inventory to yield estimates of air-sea flux cycles at the hemispheric scale. We found a larger seasonal net outgassing of APO in the Southern Hemisphere (518 ± 52.6 Tmol) than in the Northern Hemisphere (342 ± 52.1 Tmol). Differences in APO phasing and amplitude between the hemispheres suggest distinct physical and biogeochemical mechanisms driving the air-sea O₂ fluxes, such as fall outgassing of photosynthetic O₂ in the Northern Hemisphere, possibly associated with the formation of the seasonal subsurface shallow oxygen maximum. We compare our estimates with four model- and observation-based products, identifying key limitations in these products or in the tools used to create them.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GB007827","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50146261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Sources and Fate of Sedimentary Organic Matter in the Western Mediterranean Sea","authors":"Blanca Ausín,&nbsp;Gina Bossert,&nbsp;Nicola Krake,&nbsp;Sarah Paradis,&nbsp;Negar Haghipour,&nbsp;Xavier Durrieu de Madron,&nbsp;Belén Alonso,&nbsp;Timothy Eglinton","doi":"10.1029/2023GB007695","DOIUrl":"https://doi.org/10.1029/2023GB007695","url":null,"abstract":"<p>Marine sediments comprise the primary long-term sink of organic matter (OM) in marine systems. Disentangling the diverse origins of OM and the influence of the main processes that determine organic carbon (OC) fate at a global scale has proven difficult due to limited spatial data coverage. Thus, comprehensive studies of the spatial distribution of the content and geochemical characteristics of sedimentary OM at basin scales provide fundamental knowledge on the role of marine sediments in the global carbon cycle. Here, we shed light on the origin of OM and the underlying mechanisms that determine its fate in a semi-enclosed basin by examining the spatial patterns in the isotopic and elemental composition of OM in 149 core-top samples from the Western Mediterranean Sea and the adjacent Atlantic Ocean sector. Our results reveal an apparent SW-NE gradient that reverses in the Gulf of Lions in most geochemical and sedimentological features. Changes in the OC content and ẟ¹³C and Δ¹⁴C signatures are ascribed to spatial variations in marine primary productivity and the influence of varying discharge of rivers and well-developed canyons that favor the cross-shelf transport of terrestrial (and petrogenic) OC. Our results also suggest the potential influence of two other mechanisms on the geochemical signatures of OM: (a) lateral transport of allochthonous OC and selective degradation of labile OM, which potentially occurs across the studied area having a greater impact toward the north-eastern region, and (b) OM protection via association with mineral surfaces, potentially having a greater influence toward the south-western basins.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GB007695","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50151504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Rapid Expansion of Fixed Nitrogen Deficit in the Eastern Pacific Ocean Revealed by 50-Years Time Series","authors":"Natalya Evans,&nbsp;Juliana Tichota,&nbsp;Wendi Ruef,&nbsp;James Moffett,&nbsp;Allan Devol","doi":"10.1029/2022GB007575","DOIUrl":"https://doi.org/10.1029/2022GB007575","url":null,"abstract":"<p>Climate change is expected to increase the strength of ocean Oxygen Deficient Zones (ODZs), but we lack a detailed understanding of the temporal or spatial variability of these ODZs. A 50-year time series in the Eastern Tropical North Pacific (ETNP) ODZ revealed that it has strengthened by 30% from 1994 to 2019. We subdivided the ODZ into a core and a deep layer based on potential density and revealed that different processes control the magnitude of fixed nitrogen loss between these regions. We postulate that the depth of the upper ETNP ODZ water mass, the 13°C Water, influences the organic carbon supply to the core ODZ and therefore its strength. We correlated the maximum fixed nitrogen loss in the core ODZ with a nearby sedimentary nitrogen isotope record and found that this recent increase in the magnitude of fixed nitrogen loss occurred only a few times over the last 1,200 years. Using this correlation, we derived the first confidence interval for the natural variability of the maximum fixed nitrogen loss within the ETNP ODZ, which has a range of 3.3 μmol kg⁻¹ (<i>p</i> = 0.01). While the current increase is only comparable to two previous events, it is within the confidence interval for natural variability (<i>p</i> = 0.03). The deep ODZ also strengthened from 2016 to 2019 by approximately 30%, but this increase occurred more rapidly than the core ODZ, and this dramatic increase was not observed over the rest of the 40 years. Climate-driven intensification could lead to unprecedented changes in the ETNP ODZ within the next decade.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2022GB007575","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50151505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Magnitude, Trends, and Variability of the Global Ocean Carbon Sink From 1985 to 2018","authors":"Tim DeVries,&nbsp;Kana Yamamoto,&nbsp;Rik Wanninkhof,&nbsp;Nicolas Gruber,&nbsp;Judith Hauck,&nbsp;Jens Daniel Müller,&nbsp;Laurent Bopp,&nbsp;Dustin Carroll,&nbsp;Brendan Carter,&nbsp;Thi-Tuyet-Trang Chau,&nbsp;Scott C. Doney,&nbsp;Marion Gehlen,&nbsp;Lucas Gloege,&nbsp;Luke Gregor,&nbsp;Stephanie Henson,&nbsp;Ji Hyun Kim,&nbsp;Yosuke Iida,&nbsp;Tatiana Ilyina,&nbsp;Peter Landschützer,&nbsp;Corinne Le Quéré,&nbsp;David Munro,&nbsp;Cara Nissen,&nbsp;Lavinia Patara,&nbsp;Fiz F. Pérez,&nbsp;Laure Resplandy,&nbsp;Keith B. Rodgers,&nbsp;Jörg Schwinger,&nbsp;Roland Séférian,&nbsp;Valentina Sicardi,&nbsp;Jens Terhaar,&nbsp;Joaquin Triñanes,&nbsp;Hiroyuki Tsujino,&nbsp;Andrew Watson,&nbsp;Sayaka Yasunaka,&nbsp;Jiye Zeng","doi":"10.1029/2023GB007780","DOIUrl":"https://doi.org/10.1029/2023GB007780","url":null,"abstract":"<p>This contribution to the RECCAP2 (REgional Carbon Cycle Assessment and Processes) assessment analyzes the processes that determine the global ocean carbon sink, and its trends and variability over the period 1985–2018, using a combination of models and observation-based products. The mean sea-air CO₂ flux from 1985 to 2018 is −1.6 ± 0.2 PgC yr⁻¹ based on an ensemble of reconstructions of the history of sea surface pCO₂ (pCO₂ products). Models indicate that the dominant component of this flux is the net oceanic uptake of anthropogenic CO₂, which is estimated at −2.1 ± 0.3 PgC yr⁻¹ by an ensemble of ocean biogeochemical models, and −2.4 ± 0.1 PgC yr⁻¹ by two ocean circulation inverse models. The ocean also degasses about 0.65 ± 0.3 PgC yr⁻¹ of terrestrially derived CO₂, but this process is not fully resolved by any of the models used here. From 2001 to 2018, the pCO₂ products reconstruct a trend in the ocean carbon sink of −0.61 ± 0.12 PgC yr⁻¹ decade⁻¹, while biogeochemical models and inverse models diagnose an anthropogenic CO₂-driven trend of −0.34 ± 0.06 and −0.41 ± 0.03 PgC yr⁻¹ decade⁻¹, respectively. This implies a climate-forced acceleration of the ocean carbon sink in recent decades, but there are still large uncertainties on the magnitude and cause of this trend. The interannual to decadal variability of the global carbon sink is mainly driven by climate variability, with the climate-driven variability exceeding the CO₂-forced variability by 2–3 times. These results suggest that anthropogenic CO₂ dominates the ocean CO₂ sink, while climate-driven variability is potentially large but highly uncertain and not consistently captured across different methods.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"37 10","pages":""},"PeriodicalIF":5.2,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GB007780","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50129091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}