Paleoceanography and Paleoclimatology最新文献

Extreme Planktic Foraminiferal Dwarfism Across the ETM2 in the Tethys Realm in Response to Warming 特提斯海域整个 ETM2 的浮游有孔虫侏儒化现象对气候变暖的反应

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-06-01 DOI: 10.1029/2023pa004762

R. D’Onofrio, R. Barrett, D. N. Schmidt, E. Fornaciari, L. Giusberti, G. Frijia, T. Adatte, N. Sabatino, A. Monsuru, V. Brombin, V. Luciani

{"title":"Extreme Planktic Foraminiferal Dwarfism Across the ETM2 in the Tethys Realm in Response to Warming","authors":"R. D’Onofrio, R. Barrett, D. N. Schmidt, E. Fornaciari, L. Giusberti, G. Frijia, T. Adatte, N. Sabatino, A. Monsuru, V. Brombin, V. Luciani","doi":"10.1029/2023pa004762","DOIUrl":"https://doi.org/10.1029/2023pa004762","url":null,"abstract":"Pronounced warming negatively impacts ecosystem resilience in modern oceans. To offer a long‐term geological perspective of the calcareous plankton response to global warming, we present an integrated record, from two Tethyan sections (northeastern Italy), of the planktic foraminiferal and calcareous nannofossil response to the Eocene Thermal Maximum 2 hyperthermal (ETM2, ∼54 Ma). Our study reveals pronounced changes in assemblage composition and a striking dwarfing of planktic foraminiferal tests of up to 40% during the event, impacting both surface and deeper dwellers. The increased abundance of small placoliths among calcareous nannofossils is interpreted as community size reduction. Literature and our foraminiferal size data from Sites 1263 and 1209 (Atlantic and Pacific Oceans) highlights that the pronounced dwarfism is restricted to the Tethyan area. The ETM2 is characterized by warm sea surface temperatures as indicated by our δ18O data, but this warming is of global extent and cannot explain the unique dwarfism. Excluding evolutionary modifications, other potential drivers of dwarfism (eutrophication, deoxygenation, metabolic adaptation) cannot explain the exceptional dwarfism by themselves. The smallest sizes are in close temporal association with peaks in volcanic derived Hg/Th‐Hg/Rb recorded just before and at the ETM2 which could not have been brought into our sections through weathering. In contrast, size reductions are absent below and above the ETM2 at Hg peaks where δ18O data do not show warm conditions. We speculate that the local input of toxic metals from submarine volcanic emissions could have acted synergistically to warming, causing the unique dwarfism.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141390295","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}

引用次数: 0

Reconstruction of Cenozoic δ11Bsw Using a Gaussian Process 利用高斯过程重建新生代δ11Bsw

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-06-01 DOI: 10.1029/2023pa004769

Ross Whiteford, T. Heaton, M. Henehan, E. Anagnostou, H. Jurikova, Gavin L. Foster, J. Rae

{"title":"Reconstruction of Cenozoic δ11Bsw Using a Gaussian Process","authors":"Ross Whiteford, T. Heaton, M. Henehan, E. Anagnostou, H. Jurikova, Gavin L. Foster, J. Rae","doi":"10.1029/2023pa004769","DOIUrl":"https://doi.org/10.1029/2023pa004769","url":null,"abstract":"The boron isotope ratio of seawater (δ11Bsw) is a parameter which must be known to reconstruct palaeo pH and CO2 from boron isotope measurements of marine carbonates. Beyond a few million years ago, δ11Bsw is likely to have been different to modern. Palaeo δ11Bsw can be estimated by simultaneously constraining the vertical gradients in foraminiferal δ11B (Δδ11B) and pH (ΔpH). A number of subtly different techniques have been used to estimate ΔpH in the past, all broadly based on assumptions about vertical gradients in oxygen, and/or carbon, or other carbonate system constraints. In this work we pull together existing data from previous studies, alongside a constraint on the rate of change of δ11Bsw from modeling. We combine this information in an overarching statistical framework called a Gaussian Process. The Gaussian Process technique allows us to bring together data and constraints on the rate of change in δ11Bsw to generate random plausible evolutions of δ11Bsw. We reconstruct δ11Bsw, and by extension palaeo pH, across the last 65Myr using this novel methodology. Reconstructed δ11Bsw is compared to other seawater isotope ratios, namely , , and δ7Li, which we also reconstruct with Gaussian Processes. Our method provides a template for incorporation of future δ11Bsw constraints, and a mechanism for propagation of uncertainty in δ11Bsw into future studies.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141413559","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}

引用次数: 0

Holocene Variability of the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation Inferred From Chinese Speleothem δ18O Records 从中国岩溶δ18O记录推断大西洋多年涛动和太平洋十年涛动的全新世变率

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004800

Haowen Fan, Zunyu Hu, Yuhui Liu, Mengyu Wang, Chaoyong Hu

{"title":"Holocene Variability of the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation Inferred From Chinese Speleothem δ18O Records","authors":"Haowen Fan, Zunyu Hu, Yuhui Liu, Mengyu Wang, Chaoyong Hu","doi":"10.1029/2023pa004800","DOIUrl":"https://doi.org/10.1029/2023pa004800","url":null,"abstract":"The current reconstructions of the Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO) primarily rely on marine sediment proxies. However, the limited resolution of these records makes it difficult to precisely understand the short‐term dynamics of the PDO and AMO, and consequently, their influence on global climate. This study unveils two new Holocene reconstructions of AMO and PDO derived from a large‐scale compilation of speleothem isotope records (δ18Os) from Chinese monsoon region, in which spatial patterns of summer rainfall are generally accepted as good indicators of internal variability. Principal component analysis applied to Chinese δ18Os records identifies the first principal component as representative of Holocene Asian monsoon (AM) variation. This data‐driven approach reveals a significant shift in hydroclimatic conditions after 8.2 ka, potentially providing valuable insights into the underlying forcing mechanisms driving these changes. The remanent components, which show spatial rainfall patterns, are effectively validated through independent records of AMO and PDO derived from the previous paleo‐proxy based reconstructions and model simulations. The present reconstructions suggest a significantly enhanced stability of the AMO and PDO in the middle Holocene, which may explain the concurrent more stable and optimum climate observed in the AM region. These findings also imply that the Holocene AM intensity recorded in Chinese cave records is largely controlled by external forcing, whereas the regionally heterogenous rainfall is regulated by internal variability. The successful attempt on the Holocene AMO and PDO reconstructions indicates an effective isolation between different modes of climate variability from paleoclimate records.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141053174","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}

引用次数: 0

Causes of Past African Temperature Change in PMIP Simulations of the Mid‐Holocene 全新世中期 PMIP 模拟中过去非洲气温变化的原因

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004706

Charlie Marshall, Carrie Morrill, Sylvia Dee, F. Pausata, James M. Russell

{"title":"Causes of Past African Temperature Change in PMIP Simulations of the Mid‐Holocene","authors":"Charlie Marshall, Carrie Morrill, Sylvia Dee, F. Pausata, James M. Russell","doi":"10.1029/2023pa004706","DOIUrl":"https://doi.org/10.1029/2023pa004706","url":null,"abstract":"Current‐generation climate models project that Africa will warm by up to 5°C in the coming century, severely stressing African populations. Past and ongoing work indicates, however, that the models used to create these projections do not match proxy records of past temperature in Africa during the mid‐Holocene (MH), raising concerns that their future projections may house large uncertainties. Rather than reproducing proxy‐based reconstructions of MH warming relative to the Pre‐Industrial (PI), models instead simulate MH temperatures very similar to or slightly colder than the PI. This data‐model mismatch could be due to a variety of factors, including biases in model surface energy budgets or inaccurate representation of the feedbacks between temperature and hydrologic change during the “Green Sahara.” We focus on the differences among model simulations in the Paleoclimate Modeling Intercomparison Project Phases 3 and 4 (PMIP3 and PMIP4), examining surface temperature and energy budgets to investigate controls on temperature and the potential model sources of this paleoclimate data‐model mismatch. Our results suggest that colder conditions simulated by PMIP3 and PMIP4 models during the MH are in large part due to the joint impacts of feedback uncertainties in response to increased precipitation, a strengthened West African Monsoon (WAM) in the Sahel, and the Green Sahara. We extend these insights into suggestions for model physics and boundary condition changes, and discuss implications for the accuracy of future climate model projections over Africa.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141037273","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}

引用次数: 0

Tropical Warming and Intensification of the West African Monsoon During the Miocene Climatic Optimum 中新世气候最适宜期的热带变暖和西非季风加剧

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004767

E. Wubben, Bianca R. Spiering, T. Veenstra, Remco Bos, Zongyi Wang, Joost van Dijk, I. Raffi, Jakub Witkowski, Frederik J. Hilgen, F. Peterse, F. Sangiorgi, A. Sluijs

{"title":"Tropical Warming and Intensification of the West African Monsoon During the Miocene Climatic Optimum","authors":"E. Wubben, Bianca R. Spiering, T. Veenstra, Remco Bos, Zongyi Wang, Joost van Dijk, I. Raffi, Jakub Witkowski, Frederik J. Hilgen, F. Peterse, F. Sangiorgi, A. Sluijs","doi":"10.1029/2023pa004767","DOIUrl":"https://doi.org/10.1029/2023pa004767","url":null,"abstract":"Studying monsoon dynamics during past warm time periods such as the Miocene Climatic Optimum (MCO; ∼16.9–14.5 Ma) could greatly aid in better projecting monsoon intensity, in the context of future greenhouse warming. However, studies on regional MCO temperature change and its effect on the monsoons during this time period are lacking. Here, we present the first high‐resolution, low‐latitude record of sea surface temperature (SST) and paleoceanographic change covering the Miocene Climatic Optimum, in the eastern equatorial Atlantic, at Ocean Drilling Program Site 959, based on TEX86 paleothermometry. SSTs were ∼1.5°C warmer at the onset of the MCO (16.9 Ma) relative to the pre‐MCO (∼18.3–17.7 Ma). This warming was accompanied by a transient increase in %total organic carbon. Prior to the MCO, sediment composition, geochemical proxy data as well as dinoflagellate cyst assemblages imply a productive surface ocean at Site 959. Immediately following the MCO onset (∼16.9–16.5 Ma), we record an intensification of the West African Monsoon (WAM) characterized by higher amplitude variability in all proxy records on precession to obliquity timescales. We interpret increased orbital‐scale SST, biogenic Ba and dinocyst assemblage variability to represent intensification of equatorial upwelling, forced by the WAM strength. Furthermore, higher SSTs during eccentricity maxima correlate to increased relative abundances of the warm and stratification‐favoring dinocyst Polysphaeridium zoharyi, during periods of low WAM intensity. Finally, while long‐term SSTs decline toward the middle Miocene, maximum SSTs and Polysphaeridium zoharyi abundances occur during MCO peak warming at ∼15.6 Ma.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141026387","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}

引用次数: 0

Eocene Tectonic Uplifts Caused the Early Oligocene Intrusion of the Indian Monsoon Into the Tuotuohe Basin and the Increased Evaporation, Central‐Northern Tibet: Insights From the Oxygen Isotope Record 始新世构造隆起导致印度季风早期侵入沱沱河盆地以及西藏中北部蒸发增加：从氧同位素记录中获得的启示

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004698

Leyi Li, Hong Chang

引用次数: 0

Shell Reworking Impacts on Climate Variability Reconstructions Using Individual Foraminiferal Analyses 利用单个有孔虫分析贝壳重塑对气候变异性重建的影响

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004663

Natalia Bienzobas Montávez, K. Thirumalai, Gianluca Marino

{"title":"Shell Reworking Impacts on Climate Variability Reconstructions Using Individual Foraminiferal Analyses","authors":"Natalia Bienzobas Montávez, K. Thirumalai, Gianluca Marino","doi":"10.1029/2023pa004663","DOIUrl":"https://doi.org/10.1029/2023pa004663","url":null,"abstract":"Particle mixing by benthic fauna beneath the sediment‐water interface (or bioturbation) fundamentally challenges the proxy based retrieval of past climatic conditions from deep‐sea sediment cores. Previous efforts targeted the impacts of bioturbation on the nature of paleoceanographic changes gleaned from the proxy record, whereas impacts on seasonal and/or interannual variability reconstructions have received less attention. We present TurbIFA (Tracking uncertainty of reworking & bioturbation on IFA), a software that adapts and combines existing algorithms to quantitatively estimate the impact of sediment reworking and other uncertainties and assess significance of ocean and climate variability reconstructions based on individual foraminiferal analyses (IFA). Building upon previous idealized investigations of bioturbation using hydroclimate‐sediment simulations, TurbIFA advances the IFA proxy system modeling such that users may directly assess the sensitivity of their data to various local parameters related to shell reworking across the global ocean. Using the output of state‐of‐the‐art coupled atmosphere‐ocean general circulation models, TurbIFA simulates planktic foraminiferal δ18O or Mg/Ca‐temperature signal carriers and evaluates uncertainties in the sample size, analytical protocols along with as those arising from bioturbation. Application of TurbIFA to synthetic and existing data sets indicates that the significance of IFA‐based reconstructions can be assessed once the impacts of sediment accumulation rates, sediment mixed layer depths, length of time integrated by the chosen IFA sampling interval, and changes in the amplitude of climate variability (i.e., the targeted environmental signal) are comprehensively evaluated. We contend that TurbIFA can aid quantitative assessments of past seasonal and interannual variability gleaned from the paleoceanographic record.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141026668","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}

引用次数: 0

Century‐Long Records of Sedimentary Input on a Caribbean Reef From Coral Ba/Ca Ratios 从珊瑚的 Ba/Ca 比值看加勒比海礁沉积物输入的百年记录

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004746

K. Shaw, C. Standish, Sara E. Fowell, Joseph A. Stewart, K. Castillo, Justin B. Ries, Gavin L. Foster

{"title":"Century‐Long Records of Sedimentary Input on a Caribbean Reef From Coral Ba/Ca Ratios","authors":"K. Shaw, C. Standish, Sara E. Fowell, Joseph A. Stewart, K. Castillo, Justin B. Ries, Gavin L. Foster","doi":"10.1029/2023pa004746","DOIUrl":"https://doi.org/10.1029/2023pa004746","url":null,"abstract":"Coral reef ecosystems are delicately balanced and are thus prone to disruption by stressors such as storms, disease, climate variability and natural disasters. Most tropical coral populations worldwide are now in rapid decline owing to additional anthropogenic pressures, such as global warming, ocean acidification and a variety of local stressors. One such problem is the addition of excess sediment and nutrients flux to reefs from increased soil erosion from land use changes. Here we present century‐long Ba/Ca records from two Siderastrea siderea colonies as a proxy for local riverine discharge and sediment flux to the southern Mesoamerican Barrier Reef System (MBRS). The coral colonies have linear extension trends, which can be seen as a first‐order indicator for coral health and response. The coral colony that exhibits a decline in linear extension rate from the forereef of the MBRS, mainly receives riverine input from Honduras, whilst the coral from the backreef, which does not exhibit a decline in extension rate, primarily receives riverine input from more sparsely populated regions of Belize. Coral Ba/Ca increased (>70%) through time in the forereef colony, while the backreef colony showed little long‐term increase in Ba/Ca over the last century. Our results suggest that increasing sediment supply may have played a role in the decline of forereef skeletal extension in the southernmost MBRS region, likely stemming from increasing land‐use changes in Honduras.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141044655","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}

引用次数: 0

Impact of Intra‐Skeletal Calcite on the Preservation of Coral Geochemistry and Implications for Paleoclimate Reconstruction 骨骼内方解石对珊瑚地球化学保存的影响及对古气候重建的启示

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004730

Mudith M. Weerabaddana, Diane M. Thompson, Emma V. Reed, G. Farfán, Jason D. Kirk, Alice C. Kojima, D. Dettman, Kalena de Brum, Emma Kabua, Florence Edwards

{"title":"Impact of Intra‐Skeletal Calcite on the Preservation of Coral Geochemistry and Implications for Paleoclimate Reconstruction","authors":"Mudith M. Weerabaddana, Diane M. Thompson, Emma V. Reed, G. Farfán, Jason D. Kirk, Alice C. Kojima, D. Dettman, Kalena de Brum, Emma Kabua, Florence Edwards","doi":"10.1029/2023pa004730","DOIUrl":"https://doi.org/10.1029/2023pa004730","url":null,"abstract":"The geochemistry of tropical coral skeletons is widely used in paleoclimate reconstructions. However, sub‐aerially exposed corals may be affected by diagenesis, altering the aragonite skeleton through partial dissolution, or infilling of secondary minerals like calcite. We analyzed the impact of intra‐skeletal calcite on the geochemistry (δ18O, Sr/Ca, Mg/Ca, Li/Mg, Li/Ca, U/Ca, B/Ca, Ba/Ca, and Mn/Ca) of a sub‐aerially exposed Porites sp. coral. Each micro‐milled coral sample was split into two aliquots for geochemistry and X‐ray diffraction (XRD) analysis to quantify the direct impact of calcite on geochemistry. We modified the sample loading technique for XRD to detect low calcite levels (1%–2%; total uncertainty = 0.33%, 2σ) in small samples (∼7.5 mg). Calcite content ranged from 0% to 12.5%, with higher percentages coinciding with larger geochemical offsets. Sr/Ca, Li/Mg, Li/Ca, and δ18O‐derived sea‐surface temperature (SST) anomalies per 1% calcite were +0.43°C, +0.24°C, +0.11°C, and +0.008°C, respectively. A 3.6% calcite produces a Sr/Ca‐SST signal commensurate with local SST seasonality (∼1.5°C), which we propose as the cut‐off level for screening calcite diagenesis in paleo‐temperature reconstructions. Inclusion of intra‐skeletal calcite decreases B/Ca, Ba/Ca, and U/Ca values, and increases Mg/Ca values, and can therefore impact reconstructions of paleoclimate and the carbonate chemistry of the semi‐isolated calcifying fluid in corals. This study emphasizes the importance of quantifying fine‐scale calcite diagenesis to identify coral preservation levels and assure robust paleoclimate reconstructions.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141026013","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}

引用次数: 0

The Temperature of the Deep Ocean Is a Robust Proxy for Global Mean Surface Temperature During the Cenozoic 深海温度是新生代全球平均地表温度的可靠代用指标

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2024-05-01 DOI: 10.1029/2023pa004788

David Evans, Julia Brugger, G. Inglis, Paul Valdes

{"title":"The Temperature of the Deep Ocean Is a Robust Proxy for Global Mean Surface Temperature During the Cenozoic","authors":"David Evans, Julia Brugger, G. Inglis, Paul Valdes","doi":"10.1029/2023pa004788","DOIUrl":"https://doi.org/10.1029/2023pa004788","url":null,"abstract":"Reconstructing global mean surface temperature (GMST) is one of the key contributions that paleoclimate science can make in addressing societally relevant questions and is required to determine equilibrium climate sensitivity (ECS). GMST has been derived from the temperature of the deep ocean (Td), with previous work suggesting a simple Td‐GMST scaling factor of 1 prior to the Pliocene. However, this factor lacks a robust mechanistic basis, and indeed, is intuitively difficult to envisage given that polar amplification is a ubiquitous feature of past warm climate states and deep water overwhelmingly forms at high latitudes. Here, we interrogate whether and crucially, why, this relationship exists using a suite of curated data compilations and two sets of paleoclimate model simulations. We show that models and data are in full agreement that a 1:1 relationship is a good approximation. Taken together, the two sets of climate models suggest that (a) a lower sensitivity of SST in the season of deep water formation than high latitude mean annual SST in response to climate forcing, and moreover (b) a greater degree of land versus ocean surface warming are the two processes that act to counterbalance a possible polar amplification‐derived bias on Td‐derived GMST. Using this knowledge, we provide a new Cenozoic record of GMST. Our estimates are substantially warmer than similar previous efforts for much of the Paleogene and are thus consistent with a substantially higher‐than‐modern ECS during deep‐time high CO2 climate states.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141057368","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}

引用次数: 0