{"title":"Issue Information","authors":"","doi":"10.1002/palo.21175","DOIUrl":"https://doi.org/10.1002/palo.21175","url":null,"abstract":"No abstract is available for this article.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47821860","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}
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}
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}
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}
{"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}
{"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}
Mengli Chen, P. Martin, H. Ren, Run Zhang, D. Samanta, Yi-Chi Chen, K. Hughen, K. Phan, S. Vo, N. Goodkin
{"title":"Enhanced Monsoon‐Driven Upwelling in Southeast Asia During the Little Ice Age","authors":"Mengli Chen, P. Martin, H. Ren, Run Zhang, D. Samanta, Yi-Chi Chen, K. Hughen, K. Phan, S. Vo, N. Goodkin","doi":"10.1029/2022PA004546","DOIUrl":"https://doi.org/10.1029/2022PA004546","url":null,"abstract":"Climate change impacts ocean nutrient availability and will likely alter the marine food web. While climate models predict decreased average ocean productivity, the extent of these changes, especially in the marginal seas upon which large human populations depend, is not well understood. Here, we reconstructed changes in seawater phosphate concentration and nitrate source over the past 400 years, which reveals a more than 50% decline in residence time of seawater phosphate, and 8%–48% decline in subsurface nitrogen supply following the coldest period of Little Ice Age. Our data indicates a link between surface ocean nutrient supply and the East Asian Summer Monsoon strength in an economically important marginal sea. As climate models predict that the East Asian Summer monsoon will strengthen in the future, our study implies that surface ocean primary productivity may increase in the South China Sea, contrary to the predicted decrease in global average ocean productivity.","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":"46482628","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}
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}
{"title":"Hot Rocks: Interpreting Extremes of Earth Surface Temperatures From the Geologic Record","authors":"M. Suarez","doi":"10.1029/2023PA004641","DOIUrl":"https://doi.org/10.1029/2023PA004641","url":null,"abstract":"How hot can we expect Greenhouse Earth to have been in the past and the future? This is a question that deep‐time paleoclimatologists have long investigated. In a new paper by Fetrow et al. (2022), https://doi.org/10.1029/2022PA004517, deconvolving the depositional environments and burial history of continental carbonates deposited during known greenhouse climates, such as the Cretaceous, highlight the way Earth scientists can embark on understanding the clumped isotope derived temperatures and properly interpreting such temperatures.","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":"46036238","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}
Xuewen Zhou, Z. Hui, R. Vachula, Xiao Wei, Peng Chen, Jun Zhang, Xiuxi Wang, T. Peng
{"title":"Mid–Miocene Palaeofire and Its Complex Relationship With Vegetation Changes in the Wushan Basin, Northeastern Tibetan Plateau, China: Evidence From a High–Resolution Charcoal Record","authors":"Xuewen Zhou, Z. Hui, R. Vachula, Xiao Wei, Peng Chen, Jun Zhang, Xiuxi Wang, T. Peng","doi":"10.1029/2022PA004461","DOIUrl":"https://doi.org/10.1029/2022PA004461","url":null,"abstract":"Fire plays an important role in the Earth system, and is considered an essential control on global vegetation evolution and climate change. However, few Miocene high–resolution fire records have been obtained with which to assess the controls and possible drivers of fire on multiple timescales. Here, we provide a high–resolution charcoal record of the Nanyu section to reconstruct mid–Miocene fire history in the Wushan Basin. Further, we identify and assess the long–term regional fire regime (frequency and intensity) controls and possible drivers by making comparisons with published paleoclimate and paleoenvironmental records (i.e., palynomorphs, magnetic susceptibility, redness, stable isotope, pCO2 and marine δ18O data etc.). We also performed spectral analysis of the charcoal records to investigate possible controls of fire activity on orbital time scales. The analysis results indicate that (a) the reconstructed fire regime exhibits an increase from ∼16 to 13.86 Ma and a significant decrease after ∼13.86 Ma. (b) The steadily increasing regional fire activity during the period of ∼16–13.86 Ma may be caused by increased fuel ignitability and drying climate, whereas significantly decreased fire activity after ∼13.86 Ma is likely attributed to decreased fuel load due to the Mi–3b global cooling event. (c) On orbital time scales, the finding of the Earth's orbital cycles in fire proxy indicates that mid–Miocene fire activity variability in the study area was likely related to Earth's orbital forcing.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43804406","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}