Paleoceanography and Paleoclimatology最新文献_第7页

Modeling the Production of Heinrich Layers With a Sediment‐Enabled Iceberg Model 利用沉积物驱动的冰山模型模拟Heinrich层的产生

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-05-19 DOI: 10.1029/2022PA004583

M. Fendrock, A. Condron, D. McGee

{"title":"Modeling the Production of Heinrich Layers With a Sediment‐Enabled Iceberg Model","authors":"M. Fendrock, A. Condron, D. McGee","doi":"10.1029/2022PA004583","DOIUrl":"https://doi.org/10.1029/2022PA004583","url":null,"abstract":"In the North Atlantic, relatively coarse grained sediments can be found periodically throughout sediment cores spanning the Last Glacial Period. These sediments were rafted by icebergs released from the Laurentide Ice Sheet (LIS) in so‐called Heinrich Events. These “Heinrich Layers” coincide with records of global climate change, suggesting that the impact of these events was propagated beyond the North Atlantic. In order to best understand the climate context and significance of Heinrich Events, it is important to constrain the mechanism for their release from the LIS and the nature of the ice sheet itself. One approach for investigating the source of Heinrich Events is to understand the sediment load of icebergs involved, information that would inform interpretations of how those icebergs were produced. By simulating Heinrich Events in a high resolution global climate model (20–40 times the resolution of previous studies), this work investigates the processes involved in the deposition of Heinrich Layers in the North Atlantic. In these simulations, the same volume of sediment is distributed differently through the same volume of icebergs, producing profoundly different sediment records. Due to the high resolution of the model, these simulated sedimentary layers can be inspected in great detail, revealing nuances of the deposit. Only when sediment is distributed throughout the entire iceberg does the model produce a sediment pattern in agreement with observations, yet icebergs with this sediment distribution are not observed in the modern‐day.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43369120","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

Transient Shoaling, Over‐Deepening and Settling of the Calcite Compensation Depth at the Eocene‐Oligocene Transition 始新世—渐新世过渡时期方解石补偿深度的瞬态浅化、过深和沉降

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-05-18 DOI: 10.1029/2022PA004493

V. Taylor, T. Westerhold, S. Bohaty, J. Backman, T. Jones, K. Edgar, K. Egan, M. Lyle, H. Pälike, U. Röhl, J. Zachos, P. Wilson

{"title":"Transient Shoaling, Over‐Deepening and Settling of the Calcite Compensation Depth at the Eocene‐Oligocene Transition","authors":"V. Taylor, T. Westerhold, S. Bohaty, J. Backman, T. Jones, K. Edgar, K. Egan, M. Lyle, H. Pälike, U. Röhl, J. Zachos, P. Wilson","doi":"10.1029/2022PA004493","DOIUrl":"https://doi.org/10.1029/2022PA004493","url":null,"abstract":"The major Cenozoic shift from a shallow (∼3–4 km) to deep (∼4.5 km) calcite compensation depth (CCD) occurred at the Eocene‐Oligocene Transition (∼34 Ma), suggesting a strong relationship between calcium carbonate (CaCO3) cycling and Antarctic glaciation. However, the linkages between these two events are debated. Here we present new records of bulk sediment stable isotope and carbonate composition from a depth transect of sites in the low‐latitude Pacific Ocean and one site from the South Atlantic Ocean, together with a new benthic foraminiferal stable isotope record (δ13Cb and δ18Ob) from the Pacific where the sedimentary sequence is most expanded. Our records reveal a short‐lived (∼3,000 Kyr) CCD shoaling event closely associated with a negative carbon isotope excursion in the latest Eocene. This event is immediately followed by CCD deepening which occurs in two rapid (∼40 Kyr‐long) steps. Our data show that the first of these deepening steps represents recovery from the latest Eocene shoaling event while the second was closely associated with a rapid increase in δ18Ob and shows a distinctive over‐deepening and settling pattern to >5 and 4.4 km, respectively. These results, together with good agreement between Pacific and South Atlantic records, strongly suggest that the carbon cycle was perturbed globally shortly before the inception of Antarctic glaciation. Once large‐scale Antarctic glaciation was initiated, rapid further change in global seawater chemistry triggered transitory deep ocean carbonate burial fluxes far exceeding their early Oligocene steady state values.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48259401","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: 2

Issue Information 问题信息

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-05-01 DOI: 10.1002/palo.21175

引用次数: 0

Paleoceanographic Implications of Diatom Seasonal Laminations in the Upper Miocene Pisco Formation (Ica Desert, Peru) and Their Clues on the Development of the Pisco Fossil‐Lagerstätte 上中新世皮斯科组（秘鲁伊卡沙漠）硅藻季节性层合的古海洋学意义及其对皮斯科化石Lagerstätte发育的线索

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-04-29 DOI: 10.1029/2022PA004566

K. Gariboldi, J. Pike, E. Malinverno, C. Di Celma, Anna Gionacada, G. Bianucci

{"title":"Paleoceanographic Implications of Diatom Seasonal Laminations in the Upper Miocene Pisco Formation (Ica Desert, Peru) and Their Clues on the Development of the Pisco Fossil‐Lagerstätte","authors":"K. Gariboldi, J. Pike, E. Malinverno, C. Di Celma, Anna Gionacada, G. Bianucci","doi":"10.1029/2022PA004566","DOIUrl":"https://doi.org/10.1029/2022PA004566","url":null,"abstract":"The detailed study of diatom laminations conducted by means of backscattered electron imaging serves as tool to unravel details of past ocean dynamics. In this paper we apply this method to the analysis of the diatomites of Cerro Los Quesos, Upper Miocene Pisco Fm, Peru. Numerous studies have been conducted on the Pisco Fm; however, a focus on its paleoceanographic significance is still lacking. In this work, we provide information on the oceanographic setting in the area at the time of diatomites deposition. The high abundance of deep‐living Coscinodiscus laminae, proceeded by either a mixed lamina or a terrigenous one, let us hypothesize a deep position of the thermocline during the deposition of the Pisco diatomites; together with the scarcity of Chaetoceros Hyalochaete spp. resting spores, this evidence confutes the belief that equals high biogenic silica content in marine sediments with enhanced upwelling. Conversely, the depositional setting of the Pisco Fm diatomites is more similar to what is known as “permanent El Niño” (or “El Padre”) state, meaning a constant weakened upwelling (or upwelling of nutrients‐poor waters). Climate modeling warns that an increase in atmospheric CO2 may lead to this mean state in the near future. Thanks to this study we also obtained refined information on the diatomites sedimentations rates. The comparison of the Pisco diatomites sedimentation rates with those of Quaternary diatomites gave strength to the hypothesis that the formation of the vertebrate Lagerstätte may have been enhanced, among others, by the so‐called “impact‐burial” mechanism.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49665499","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

Evolution of Global Ocean Tide Levels Since the Last Glacial Maximum 上一次冰川盛期以来全球海平面的演变

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-04-26 DOI: 10.1029/2022PA004556

R. Sulzbach, V. Klemann, G. Knorr, H. Dobslaw, H. Dümpelmann, G. Lohmann, M. Thomas

{"title":"Evolution of Global Ocean Tide Levels Since the Last Glacial Maximum","authors":"R. Sulzbach, V. Klemann, G. Knorr, H. Dobslaw, H. Dümpelmann, G. Lohmann, M. Thomas","doi":"10.1029/2022PA004556","DOIUrl":"https://doi.org/10.1029/2022PA004556","url":null,"abstract":"This study addresses the evolution of global tidal dynamics since the Last Glacial Maximum focusing on the extraction of tidal levels that are vital for the interpretation of geologic sea‐level markers. For this purpose, we employ a truly‐global barotropic ocean tide model which considers the non‐local effect of Self‐Attraction and Loading. A comparison to a global tide gauge data set for modern conditions yields agreement levels of 65%–70%. As the chosen model is data‐unconstrained, and the considered dissipation mechanisms are well understood, it does not have to be re‐tuned for altered paleoceanographic conditions. In agreement with prior studies, we find that changes in bathymetry during glaciation and deglaciation do exert critical control over the modeling results with minor impact by ocean stratification and sea ice friction. Simulations of 4 major partial tides are repeated in time steps of 0.5–1 ka and augmented by 4 additional partial tides estimated via linear admittance. These are then used to derive time series from which the tidal levels are determined and provided as a global data set conforming to the HOLSEA format. The modeling results indicate a strengthened tidal resonance by M2, but also by O1, under glacial conditions, in accordance with prior studies. Especially, a number of prominent changes in local resonance conditions are identified, that impact the tidal levels up to several meters difference. Among other regions, resonant features are predicted for the North Atlantic, the South China Sea, and the Arctic Ocean.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49351073","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: 1

A Spatiotemporal Assessment of Extreme Cold in Northwestern North America Following the Unidentified 1809 CE Volcanic Eruption 1809年未确认的火山喷发后北美西北部极端寒冷的时空评估

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-04-18 DOI: 10.1029/2022PA004581

C. Leland, R. D’Arrigo, N. Davi, K. J. Anchukaitis, L. Andreu‐Hayles, T. Porter, T. Galloway, M. Mant, G. Wiles, R. Wilson, S. Beaulieu, R. Oelkers, B. Gaglioti, M. Rao, E. Reid, T. Nixon

{"title":"A Spatiotemporal Assessment of Extreme Cold in Northwestern North America Following the Unidentified 1809 CE Volcanic Eruption","authors":"C. Leland, R. D’Arrigo, N. Davi, K. J. Anchukaitis, L. Andreu‐Hayles, T. Porter, T. Galloway, M. Mant, G. Wiles, R. Wilson, S. Beaulieu, R. Oelkers, B. Gaglioti, M. Rao, E. Reid, T. Nixon","doi":"10.1029/2022PA004581","DOIUrl":"https://doi.org/10.1029/2022PA004581","url":null,"abstract":"Two large volcanic eruptions contributed to extreme cold temperatures during the early 1800s, one of the coldest phases of the Little Ice Age. While impacts from the massive 1815 Tambora eruption in Indonesia are relatively well‐documented, much less is known regarding an unidentified volcanic event around 1809. Here, we describe the spatial extent, duration, and magnitude of cold conditions following this eruption in northwestern North America using a high‐resolution network of tree‐ring records that capture past warm‐season temperature variability. Extreme and persistent cold temperatures were centered around the Gulf of Alaska, the adjacent Wrangell‐St Elias Mountains, and the southern Yukon, while cold anomalies diminished with distance from this core region. This distinct spatial pattern of temperature anomalies suggests that a weak Aleutian Low and conditions similar to a negative phase of the Pacific Decadal Oscillation could have contributed to regional cold extremes after the 1809 eruption.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48923214","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: 1

The Zonal Patterns in Late Quaternary Tropical South American Precipitation 晚第四纪热带南美洲降水的纬向格局

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-04-01 DOI: 10.1029/2022PA004498

T. Kukla, M. Winnick, M. Laguë, Z. Xia

{"title":"The Zonal Patterns in Late Quaternary Tropical South American Precipitation","authors":"T. Kukla, M. Winnick, M. Laguë, Z. Xia","doi":"10.1029/2022PA004498","DOIUrl":"https://doi.org/10.1029/2022PA004498","url":null,"abstract":"Speleothem oxygen isotope records (δ18O) of tropical South American rainfall in the late Quaternary show a zonal “South American Precipitation Dipole” (SAPD). The dipole is characterized by opposing east‐west precipitation anomalies compared to the present—wetter in the east and drier in the west at the mid‐Holocene (∼7 ka), and drier in the east and wetter in the west at the Last Glacial Maximum (∼21 ka). However, the SAPD remains enigmatic because it is expressed differently in western versus eastern δ18O records and isotope‐enabled climate model simulations usually misrepresent the magnitude and/or spatial pattern of δ18O change. Here, we address the SAPD enigma in two parts. First, we re‐interpret the δ18O data to account for upwind rainout effects that are known to be pervasive in tropical South America, but are not always considered in Quaternary paleoclimate studies. Our revised interpretation reconciles the δ18O data with cave infiltration and other proxy records, and indicates that the centroid of tropical South American rainfall has migrated zonally over time. Second, using an energy balance model of tropical atmospheric circulation, we hypothesize that zonal migration of the precipitation centroid can be explained by regional energy budget shifts, such as changing Saharan albedo associated with the African Humid Period, that have not been modeled in previous SAPD studies. This hypothesis of a migrating precipitation centroid presents a new framework for interpreting δ18O records from tropical South America and may help explain the zonal rainfall anomalies that predate the late Quaternary.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45392946","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

Thank You to Our 2022 Peer Reviewers 感谢我们2022年的同行评审

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-04-01 DOI: 10.1029/2023pa004653

M. Huber, U. Röhl

{"title":"Thank You to Our 2022 Peer Reviewers","authors":"M. Huber, U. Röhl","doi":"10.1029/2023pa004653","DOIUrl":"https://doi.org/10.1029/2023pa004653","url":null,"abstract":"Once a year we take the opportunity to thank the reviewers whose difficult, important work is never sufficiently recognized. Three years into the COVID-19 pandemic, reviewers continued to show deep resolve to support their community, by providing thorough, timely reviews aiming to improve manuscripts, while simultaneously dealing with very difficult personal and professional circumstances. Without their intense, robust, and helpful attention, all the science we do would be diminished. Matthew and Ulla would like to express their gratitude and appreciation for your efforts this year and their hope for improvement in 2023 and beyond. Thank you to the 339 reviewers who submitted 473 reviews in the journal last year. Individuals in italics provided three or more reviews for Paleoceanography and Paleoclimatology during the year. Abbott, April Abell, Jordan Acosta, Rene Paul Agnini, Claudia Ai, Xuyuan Allen, Katherine Anagnostou, Eleni Anchukaitis, Kevin Anderson, Robert Arbic, Brian Archer, David Arreguín-Rodríguez, Gabriela Atwood, Alyssa Babila, Tali Baker, Paul Bakker, Pepijn Barron, John Barth, Aaron Bassinot, Franck Batenburg, Sietske Baumgartner, Aly Belanger, Christina Berenice, Sophie Bhattacharya, Tripti","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48952393","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

Enhanced Monsoon‐Driven Upwelling in Southeast Asia During the Little Ice Age 小冰期东南亚季风驱动的上升流增强

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-04-01 DOI: 10.1029/2022PA004546

Mengli Chen, P. Martin, H. Ren, Run Zhang, D. Samanta, Yi-Chi Chen, K. Hughen, K. Phan, S. Vo, N. Goodkin

引用次数: 0

A Window Into Eastern Mediterranean Productivity Conditions Over Three Pliocene Precession‐Forced Climate Cycles 三次上新世侵入-强迫气候周期东地中海生产力条件的窗口

IF 3.5 2区地球科学

Paleoceanography and Paleoclimatology Pub Date : 2023-04-01 DOI: 10.1029/2022PA004550

Anna Cutmore, N. Bale, G. Lange, I. Nijenhuis, Lucas, Joost Lourens

{"title":"A Window Into Eastern Mediterranean Productivity Conditions Over Three Pliocene Precession‐Forced Climate Cycles","authors":"Anna Cutmore, N. Bale, G. Lange, I. Nijenhuis, Lucas, Joost Lourens","doi":"10.1029/2022PA004550","DOIUrl":"https://doi.org/10.1029/2022PA004550","url":null,"abstract":"Here, we explore the importance of export productivity versus anoxia in the formation of sedimentary layers with enhanced total organic carbon (TOC) content. We use geochemical, sedimentological and micropaleontological records from two SW Sicily outcropping successions, Lido Rossello (LR) and Punta di Maiata (PM), over three Early Pliocene precession‐forced climate cycles (4.7–4.6 million years ago [Ma]). Gray marls, deposited during precession minima, show enhanced TOC in both records. We suggest that basin‐wide, low‐oxygenated bottom‐waters, resulting from freshwater‐induced stratification during precession minimum, was integral to preserving gray marl TOC. Furthermore, prolonged eastern Mediterranean stratification may have produced a deep chlorophyll maximum (DCM), leading to “shade‐flora” dominated productivity. The LR succession displays two unique laminated layers containing enhanced TOC. These laminations do not occur at specific times in the precession cycle or in time‐equivalent PM samples. They are likely to have been produced by an intermittent dysoxic/anoxic pool at LR, caused by a local depression, which enhanced TOC preservation. Consequently, the laminations provide a rare window into “true” eastern Mediterranean productivity conditions during precession maxima, as organic matter is typically poorly preserved during these period due to enhanced ventilation. The laminated “windows” indicate that eastern Mediterranean export productivity may not have been significantly lower during precession maxima compared to precession minima, as previously thought. During these periods, productivity conditions are likely to have been comparable to the modern eastern Mediterranean, with a spring‐bloom caused by enhanced winter/spring deep‐water mixing preceding a summer “shade‐flora” bloom caused by a summer‐stratification induced DCM.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47808104","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