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Seasonality in Holocene Temperature Reconstructions in Southwestern China Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-18 Xiaoshuang Sun; Cheng Zhao; Can Zhang; Xiaoping Feng; Tianlong Yan; Xiangdong Yang; Ji Shen
Reconstructions of global surface temperature, dominated by records from the northern extratropics, show an apparent Holocene cooling trend after the early Holocene climatic optimum. However, model simulations suggest a global warming Holocene tendency. This “Holocene temperature conundrum” may be caused by the seasonal bias of paleotemperature proxies. Here we report a quantitative Holocene record
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Deglacial ventilation changes in the deep Southwest Pacific Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2021-01-18 Yuhao Dai; Jimin Yu; Patrick A. Rafter
Processes underlying changes in the oceanic carbon storage during the Last Glacial Maximum and the subsequent deglaciation are not fully understood. Here, we present a new high‐resolution radiocarbon reconstruction (expressed as δ14R) at the depth of the modern Lower Circumpolar Deep Water from the Pacific Sector of the Southern Ocean. Our record shows δ14R increases during Heinrich Stadial 1 and the
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The spatial distribution of aeolian dust and terrigenous fluxes in the tropical Atlantic Ocean since the Last Glacial Maximum Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2021-01-18 George H. Rowland; Laura F. Robinson; Katharine R. Hendry; Hong Chin Ng; David McGee; Jerry F. McManus
The flux of terrestrial material from the continents to the oceans links the lithosphere, hydrosphere and biosphere through physical and biogeochemical processes, with important implications for Earth's climate. Quantitative estimates of terrigenous fluxes from sources such as rivers, aeolian dust and resuspended shelf sediments are required to understand how the processes delivering terrigenous material
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New magnetostratigraphic insights from Iceberg Alley on the rhythms of Antarctic climate during the Plio‐Pleistocene Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2021-01-18 Brendan T. Reilly; Lisa Tauxe; Stefanie Brachfeld; Maureen Raymo; Ian Bailey; Sidney Hemming; Michael E. Weber; Trevor Williams; Marga Garcia; Michelle Guitard; Yasmina M. Martos; Lara F. Pérez; Xufeng Zheng; Linda Armbrecht; Fabricio G. Cardillo; Zhiheng Du; Gerson Fauth; Anna Glueder; Marcus Gutjahr; Iván Hernández‐Almeida; Frida S. Hoem; Ji‐Hwan Hwang; Mutsumi Iizuka; Yuji Kato; Bridget Kenlee;
International Ocean Discovery Program (IODP) Expedition 382 in the Scotia Sea's “Iceberg Alley” recovered among the most continuous and highest resolution stratigraphic records in the Southern Ocean near Antarctica spanning the last 3.3 Myr. Sites drilled in Dove Basin (U1536/U1537) have well‐resolved magnetostratigraphy and a strong imprint of orbital forcing in their lithostratigraphy. All magnetic
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Holocene moisture variability and its lagged response to summer insolation revealed by eolian deposits in the Lake Qinghai Basin, NE Tibetan Plateau Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2021-01-18 Zhiyong Ding; Ruijie Lu; Lindong Wang
The evolution of the East Asian Summer Monsoon (EASM) and its mechanism since the Holocene remains controversial. Here we investigate four eolian sediment sequences in the Lake Qinghai Basin (LQB), Northeastern Tibetan Plateau (NETP), in the marginal zone of the modern EASM. The results indicate that paleoclimatological interpretation of the color parameters and CaCO3 in eolian sand‐paleosol sequence
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Variations in mid‐ to late Holocene nitrogen supply to northern Great Barrier Reef Halimeda macroalgal bioherms Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2021-01-18 Mardi McNeil; Luke Nothdurft; Dirk Erler; Quan Hua; Jody M. Webster
The northern Great Barrier Reef (GBR) Halimeda bioherms have accumulated on the outer continental shelf from calcium carbonate algal sediments over the past ∼10,000 years and cover >6000 km2 of shelf area. As such, Halimeda bioherms play a key role in the shallow marine carbon cycle over millennial timescales. The main source of nitrogen (N) to these bioherms is thought to be westward transport of
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Fates of Paleo‐Antarctic Bottom Water During the Early Eocene: Based on a Lagrangian Analysis of IPSL‐CM5A2 Climate Model Simulations Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-14 Yurui Zhang; Nicolas Grima; Thierry Huck
Both deepwater formation and the obduction processes converting dense deep water to lighter surface water are the engine for the global meridional overturning circulation (MOC). Their spatio‐temporal variations effectively modify the ocean circulation and related carbon cycle, which affects climate evolution throughout geological time. Using early‐Eocene bathymetry and enhanced atmospheric CO2 concentration
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Issue Information Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2021-01-06
No abstract is available for this article.
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Millennial‐scale changes in bottom water temperature and water mass exchange through the Fram Strait 79ºN, 63–13 ka Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-31 N. El bani Altuna; M. M. Ezat; M. Greaves; T. L. Rasmussen
The Svalbard margin, in the eastern Fram Strait with its high sediment accumulation, form a key area for the reconstruction of water mass and heat exchange between the North Atlantic and Arctic Ocean in relation to abrupt climate changes as seen in glacial Greenland Interstadial and Greenland Stadial (GI‐GS) events. Here, we present a bottom water temperature (BWT) record from the northern Nordic Seas
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Distinguishing Glacial AMOC and Interglacial Non‐AMOC Nd Isotopic Signals in the Deep Western Atlantic Over the Last 1 Myr Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-03 Maria Jaume‐Seguí; Joohee Kim; Leopoldo D. Pena; Steven L. Goldstein; Karla P. Knudson; Maayan Yehudai; Alison E. Hartman; Louise Bolge; Patrizia Ferretti
The global thermohaline circulation plays a major role in regulating global climate, driven by the formation of North Atlantic Deep Water (NADW). ODP Site 1063 on the Bermuda Rise, at the interface of NADW and Southern Ocean‐sourced water, appears an ideal location to study the relationships between ocean circulation and climate. This study reports Nd isotope ratios at Site 1063 that extend to ~1 Ma
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Reconstructing paleo‐oxygenation for the last 54,000 years in the Gulf of Alaska using cross‐validated benthic foraminiferal and geochemical records Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-28 Sharon; Christina Belanger; Jianghui Du; Alan Mix
Holocene and Pleistocene marine sediment records in the North Pacific record multiple dysoxic events proximal to continental margins and oxygen minimum zones (OMZs). High‐resolution paleoenvironmental studies in the Gulf of Alaska (GoA) were previously restricted to the last ∼17,000 years, limiting our knowledge of oxygenation in the high latitude North Pacific. Here we develop a ∼54,000 year‐long
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Atlantic Ocean ventilation changes across the last deglaciation and their carbon cycle implications Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-27 L. C. Skinner; E. Freeman; D. Hodell; C. Waelbroeck; N. Vazquez Riveiros; A.E Scrivner
Changes in ocean ventilation, controlled by both overturning rates and air‐sea gas exchange, are thought to have played a central role in atmospheric CO2 rise across the last deglaciation. Here we constrain the nature of Atlantic Ocean ventilation changes over the last deglaciation using radiocarbon and stable carbon isotopes from two depth transects in the Atlantic basin. Our findings broadly cohere
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Decreasing Atmospheric CO2 During the Late Miocene Cooling Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-10 Thomas Tanner; Iván Hernández‐Almeida; Anna Joy Drury; José Guitián; Heather Stoll
A pronounced late Miocene cooling (LMC) from ~7 to 5.7 Ma has been documented in extratropical and tropical sea surface temperature records, but to date, available proxy evidence has not revealed a significant pCO2 decline over this event. Here, we provide a new, high‐resolution pCO2 proxy record over the LMC based on alkenone carbon isotopic fractionation (εp) measured in sediments from the South
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Deep Thermohaline Circulation Across the Closure of the Central American Seaway Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-03 N. Öğretmen; R. Schiebel; K. P. Jochum; B. Stoll; U. Weis; J. Repschläger; A. Jentzen; S. Galer; G. H. Haug
The closure of the Central American Seaway (CAS) resulted in changes of ocean‐climate dynamics since the late Miocene following the uplift of northern Andes. Reconstructing the bottom‐water temperatures (BWTs) of the Caribbean Sea illustrates feedbacks of the closure on the ocean‐climate system including deep‐water dynamics of the Caribbean Sea. Here, Mg/Ca‐derived BWTs of the Plio‐Pleistocene Caribbean
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The Miocene: the Future of the Past Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-23 M. Steinthorsdottir; H. K. Coxall; A. M. de Boer; M. Huber; N. Barbolini; C. D. Bradshaw; N. J. Burls; S. J. Feakins; E. Gasson; J. Henderiks; A. Holbourn; S. Kiel; M. J. Kohn; G. Knorr; W. M. Kürschner; C. H. Lear; D. Liebrand; D. J. Lunt; T. Mörs; P. N. Pearson; M. J. Pound; H. Stoll; C. A. E. Strömberg
The Miocene epoch (23.03–5.33 Ma) was a time interval of global warmth, relative to today. Continental configurations and mountain topography transitioned towards modern conditions, and many flora and fauna evolved into the same taxa that exist today. Miocene climate was dynamic: long periods of early and late glaciation bracketed a ∼2 Myr greenhouse interval – the Miocene Climatic Optimum (MCO). Floras
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Controls Since the mid‐Pleistocene Transition on Sedimentation and Primary Productivity Downslope of Totten Glacier, East Antarctica Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-09 L. Holder; M. Duffy; B. Opdyke; A. Leventer; A. Post; P. O'Brien; L. K. Armand
The rapidly thinning Totten Glacier on the Sabrina Coast, East Antarctica, is the primary drainage outlet for ice within the Aurora Subglacial Basin, which could destabilize under the current atmospheric warming trend. There is growing need for direct geological evidence from the Sabrina Coast to frame late twentieth century Totten melting in the context of past warm climate analogs. Addressing this
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Reconstructing Western Boundary Current Stability in the North Atlantic Ocean for the Past 700 Kyr From Globorotalia truncatulinoides Coiling Ratios Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-16 Katharina Billups; Maoli Vizcaíno; Josephine Chiarello; Emily A. Kaiser
Down‐core changes in the coiling direction of Globorotalia truncatulinoides in the northwestern subtropical Atlantic (KNR140‐37PC and Ocean Drilling Program Sites 1063, 1059, 1056, 1058) provide a tracer for the hydrographic conditions in the western boundary current over the past 700 kyr (Marine Isotope Stage, MIS, 1–17). A consistent association between percent G. truncatulinoides (sinistral) abundances
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Reconstructing Depositional Rates and Their Effect on Paleoenvironmental Proxies: The Case of the Lau Carbon Isotope Excursion in Gotland, Sweden Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-17 E. Jarochowska; T. Nohl; M. Grohganz; N. Hohmann; T. R. A. Vandenbroucke; A. Munnecke
Variations in depositional rates affect the temporal depositional resolutions of proxies used for paleoenvironmental reconstructions; for example, condensation can make reconstructed environmental changes appear very abrupt. This is commonly addressed by transforming proxy data using age models, but this approach is limited to situations where numerical ages are available or can be reliably inferred
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Monsoon Enhanced Silicate Weathering as a New Atmospheric CO2 Consumption Mechanism Contributing to Fast Late Miocene Global Cooling Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-18 Y. Yang; C. Ye; A. Galy; X. Fang; Y. Xue; Y. Liu; R. Yang; R. Zhang; W. Han; W. Zhang; X. Ruan
Fast late Miocene global cooling since ∼7 Ma accompanied by less changeable atmospheric CO2 levels revealed by existing proxy reconstructions has suggested an intriguing tectonic‐climate link that remains controversial. Here, we present late Cenozoic clay mineral records of the silicate weathering intensity from the Chinese Loess Plateau and northeastern Tibetan Plateau to demonstrate a remarkable
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Coral Record of Younger Dryas Chronozone Warmth on the Great Barrier Reef Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-11 Logan D. Brenner; Braddock K. Linsley; Jody M. Webster; Donald Potts; Thomas Felis; Michael K. Gagan; Mayuri Inoue; Helen McGregor; Atsushi Suzuki; Alexander Tudhope; Tezer Esat; Alex Thomas; William Thompson; Stewart Fallon; Marc Humblet; Manish Tiwari; Yusuke Yokoyama
The Great Barrier Reef (GBR) is an internationally recognized and widely studied ecosystem, yet little is known about its sea surface temperature (SST) evolution since the Last Glacial Maximum (LGM) (~20 kyr BP). Here, we present the first paleo‐application of Isopora coral‐derived SST calibrations to a suite of 25 previously published fossil Isopora from the central GBR spanning ~25–11 kyr BP. The
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Adaptations of Coccolithophore Size to Selective Pressures During the Oligocene to Early Miocene High CO2 World Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-10 José Guitián; Tom Dunkley Jones; Ivan Hernández‐Almeida; Tim Löffel; Heather M. Stoll
Culture experiments with coccolithophore algae—the dominant group of marine calcifying phytoplankton—imply a strong sensitivity in growth rate, degree of cellular calcification, and cell size to changes in the carbon chemistry of their growth environment. These results underpin recent studies that have explored how these physiological parameters have varied on geological time scales, in response to
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Dust‐Drought Nexus in the Southwestern United States: A Proxy‐Model Comparison Approach Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-12-03 S. H. Arcusa; N. P. McKay; C. M. Carrillo; T. R. Ault
The U.S. Southwest is naturally prone to dust and drought. With a high risk of unprecedented drought in the future due to climate change, changes in the dust cycle are expected. Whereas paleo records of dust deposition from the region suggest that past megadroughts did not coincide with elevated dust levels, modern studies indicate higher dust during drier conditions. To examine this disagreement,
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Middle Miocene Intensification of South Asian Monsoonal Rainfall Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-27 Xueping Yang; Jeroen Groeneveld; Zhimin Jian; Stephan Steinke; Liviu Giosan
During the middle Miocene, Earth's climate changed from a global warm period (Miocene Climatic Optimum) into a colder one with the expansion of the Antarctic ice sheet. This prominent climate transition was also a period of drastic changes in global atmospheric circulation. The development of the South Asian monsoon is not well understood and mainly derived from proxy records of wind strength. Data
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Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-06 Sora L. Kim; Sarah S. Zeichner; Albert S. Colman; Howie D. Scher; Jürgen Kriwet; Thomas Mörs; Matthew Huber
Many explanations for Eocene climate change focus on the Southern Ocean—where tectonics influenced oceanic gateways, ocean circulation reduced heat transport, and greenhouse gas declines prompted glaciation. To date, few studies focus on marine vertebrates at high latitudes to discern paleoecological and paleoenvironmental impacts of this climate transition. The Tertiary Eocene La Meseta (TELM) Formation
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New Insights Into Kuroshio Current Evolution Since the Last Deglaciation Based on Paired Organic Paleothermometers From the Middle Okinawa Trough Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-20 Qian Li; Guangxue Li; Min‐Te Chen; Jishang Xu; Shidong Liu; Mengna Chen
As an important hydrological parameter in the upper ocean, the depth of the thermocline (DOT) in the Okinawa Trough (OT) is closely linked to air‐sea interactions and Kuroshio Current (KC) intrusions. However, high‐resolution DOT records in the OT since the last deglaciation have not been well reconstructed. In this study, we generated surface ( ) and shallow subsurface ( ) temperature records from
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Late Pleistocene Carbon Cycle Revisited by Considering Solid Earth Processes Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-20 Peter Köhler; Guy Munhoven
The importance of volcanic CO2 release, continental weathering, and coral reef growth on the global carbon cycle has been highlighted by several different studies. Based on these independent approaches, we here revisit the last 800 kyr with the box model BICYCLE, which has been extended to be able to address these solid Earth contributions to the carbon cycle. We show that the volcanic outgassing of
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A Ternary Mixing Model Approach Using Benthic Foraminifer δ13C‐δ18O Data to Reconstruct Late Pliocene Deep Atlantic Water Mass Mixing Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-09 Carolien M. H. van der Weijst; Josse Winkelhorst; Lucas Lourens; Maureen E. Raymo; Francesca Sangiorgi; Appy Sluijs
Late Pliocene deep Atlantic δ13C data have been interpreted as evidence for enhanced Atlantic Meridional Overturning Circulation (AMOC) compared to the present, but this hypothesis is not supported by the Pliocene Model Intercomparison Project (PlioMIP). Here, we adopt a new approach to assess variability in deep ocean circulation based on paired stable carbon (δ13C) and oxygen isotopes (δ18O) of benthic
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An Assessment of xsBa Flux as a Paleoproductivity Indicator and Its Water‐Depth Dependence in the Easternmost Equatorial Pacific Ocean Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-12 Ajay K. Singh; Franco Marcantonio; Mitchell Lyle
We present the first regional‐scale records of biogenic Barium (xsBa) fluxes in the Panama basin of the eastern‐equatorial margin of the Pacific Ocean in order to assess xsBa as a paleoproductivity proxy. Measurements of xsBa from 13 cores that range in water depths from about 700 to 3,000 m show an increase in 230Th‐normalized xsBa mass accumulation rates (MARs) with increasing water depth during
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The Flux and Provenance of Dust Delivered to the SW Pacific During the Last Glacial Maximum Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-23 M. D. Trudgill; R. Shuttleworth; H. C. Bostock; A. Burke; M. J. Cooper; R. Greenop; G. L. Foster
Atmospheric dust is a primary source of iron (Fe) to the open ocean, and its flux is particularly important in the high nutrient, low chlorophyll (HNLC) Southern Ocean where Fe currently limits productivity. Alleviation of this Fe limitation in the Subantarctic Zone of the Atlantic by increased dust‐borne Fe supply during glacial periods has been shown to increase primary productivity. However, previous
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Initiation of the Western Pacific Warm Pool at the Middle Miocene Climate Transition? Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-09 S. M. Sosdian; C. H. Lear
Across the middle Miocene, Earth's climate underwent a major cooling and expansion of the Antarctic ice sheet. However, the associated response and development of the tropical climate system is not fully understood, in part because this is influenced by both global climate and also low‐latitude tectonic gateways and paleoceanography. Here we use combined δ18O and Mg/Ca of planktic foraminifera to reconstruct
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Unraveling Glacial Hydroclimate in the Indo‐Pacific Warm Pool: Perspectives From Water Isotopes Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-09 Grace Windler; Jessica E. Tierney; Jiang Zhu; Christopher J. Poulsen
The Indo‐Pacific Warm Pool (IPWP) is home to the warmest sea surface temperatures in the world oceans, favoring strong tropospheric convection and heavy rainfall. The mechanisms controlling long‐term change in the region's hydroclimate are still uncertain. Here, we present a 450,000‐year record of precipitation δD from southern Sumatra that records a consistent pattern of glacial isotopic enrichment
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Provenance and weathering of clays delivered to the Bay of Bengal during the middle Miocene: Linkages to tectonics and monsoonal climate Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-25 Lisa Bretschneider; Ed C. Hathorne; Huang Huang; Julia Lübbers; Karlos G. D. Kochhann; Ann Holbourn; Wolfgang Kuhnt; Rasmus Thiede; Daniel Gebregiorgis; Liviu Giosan; Martin Frank
Tectonics and regional monsoon strength control weathering and erosion regimes of the watersheds feeding into the Bay of Bengal, which are important contributors to global climate evolution via carbon cycle feedbacks. The detailed mechanisms controlling the input of terrigenous clay to the Bay of Bengal on tectonic to orbital timescales are, however, not yet well understood. We produced orbital‐scale
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Issue Information Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-24
No abstract is available for this article.
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Warm Middle Miocene Indian Ocean Bottom Water Temperatures: Comparison of Clumped Isotope and Mg/Ca‐Based Estimates Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-14 S. E. Modestou; T. J. Leutert; A. Fernandez; C. H. Lear; A. N. Meckler
The middle Miocene is an important analogue for potential future warm climates. However, few independent deep ocean temperature records exist, though these are important for climate model validation and estimates of changes in ice volume. Existing records, all based on the foraminiferal Mg/Ca proxy, suggest that bottom water temperatures were 5–8°C warmer than present. In order to improve confidence
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Persistent Link Between Caribbean Precipitation and Atlantic Ocean Circulation During the Last Glacial Revealed by a Speleothem Record From Puerto Rico Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-03 Sophie F. Warken; Rolf Vieten; Amos Winter; Christoph Spötl; Thomas E. Miller; Klaus P. Jochum; Andrea Schröder‐Ritzrau; Augusto Mangini; Denis Scholz
The sensitivity of tropical Atlantic precipitation patterns to the mean position of the Intertropical Convergence Zone (ITCZ) at different time scales is well‐known. However, recent research suggests a more complex behavior of the northern hemispheric tropical rain belt related to the ITCZ in the western tropical Atlantic. Here we present a precisely dated speleothem multi‐proxy record from a well‐monitored
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Delays, Discrepancies, and Distortions: Size‐Dependent Sediment Mixing and the Deep‐Sea Record of the Paleocene‐Eocene Thermal Maximum From ODP Site 690 (Weddell Sea) Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-29 Brittany Hupp; D. Clay Kelly
The deep‐sea sedimentary record of Ocean Drilling Program Site 690 (Weddell Sea) has figured prominently in the study of an ancient (~56 Ma) global warming event referred to as the Paleocene‐Eocene Thermal Maximum (PETM). Yet discrepancies in the timing, amplitude, and structure of the isotopic excursions marking the PETM exist between the bulk‐carbonate and planktic foraminifer stable isotope (δ13C
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Influence of Elevated Nd Fluxes on the Northern Nd Isotope End Member of the Atlantic During the Early Holocene Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-29 Frerk Pöppelmeier; Jeemijn Scheen; Patrick Blaser; Jörg Lippold; Marcus Gutjahr; Thomas F. Stocker
The neodymium (Nd) isotopic composition of seawater is a valuable tool for the reconstruction of past water mass provenance and hence deep water geometry. A meaningful interpretation of Nd isotope down‐core records requires knowledge of potential variations of water mass end member characteristics. While often assumed temporally constant, recent investigations revealed glacial‐interglacial variability
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Holocene Interactions Between Glacier Retreat, Sea Ice Formation, and Atlantic Water Advection at the Inner Northeast Greenland Continental Shelf Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-16 Nicole Syring; Jeremy M. Lloyd; Ruediger Stein; Kirsten Fahl; Dave H. Roberts; Louise Callard; Colm O'Cofaigh
During the past four decades significant decrease in Arctic sea ice and a dramatic ice mass loss of the Greenland Ice Sheet (GIS) has been coincident with global warming and an increase in atmospheric CO2. In Northeast Greenland significant mass loss from the outlet glaciers Nioghalvfjerdsbræ (79NG) and Zachariæ Isstrøm (ZI) and intensive seasonal breakup of the local Norske Øer Ice Barrier (NØIB)
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Anti‐phased Miocene ice volume and CO2 changes by transient Antarctic ice sheet variability Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-11-07 L. B. Stap; G. Knorr; G. Lohmann
Geological evidence indicates large continental‐scale Antarctic ice volume variations during the early and mid‐Miocene. On million‐year timescales, these variations can largely be explained by equilibrium Antarctic ice sheet (AIS) simulations. In contrast, on shorter orbital timescales, the AIS needs not be in equilibrium with the forcing and ice volume variations may be substantially different. Here
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A Comparison of the CMIP6 midHolocene and lig127k Simulations in CESM2 Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-16 Bette L. Otto‐Bliesner; Esther C. Brady; Robert A. Tomas; Samuel Albani; Patrick J. Bartlein; Natalie M. Mahowald; Sarah L. Shafer; Erik Kluzek; Peter J. Lawrence; Gunter Leguy; Mathew Rothstein; Aleah N. Sommers
Results are presented and compared for the Community Earth System Model version 2 (CESM2) simulations of the middle Holocene (MH, 6 ka) and Last Interglacial (LIG, 127 ka). These simulations are designated as Tier 1 experiments (midHolocene and lig127k) for the Coupled Model Intercomparison Project phase 6 (CMIP6) and the Paleoclimate Modeling Intercomparison Project phase 4 (PMIP4). They use the low‐top
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Evolution of the Oligotrophic West Pacific Warm Pool During the Pliocene‐Pleistocene Boundary Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-20 Himanshu Bali; Anil K. Gupta; Kuppusamy Mohan; K. Thirumalai; Sameer K. Tiwari; Mruganka K. Panigrahi
This study investigates the development of oligotrophic conditions, thickening, and zonal and meridional contraction of the West Pacific Warm Pool (WPWP) during the Pliocene. It has been hypothesized that the evolution of the WPWP and the establishment of strong equatorial Pacific zonal gradients are closely related to the narrowing of the Indonesian Gateway (IG) as well as the closure of the Central
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Piacenzian Environmental Change and the Onset of Cool and Dry Conditions in Tropical South America Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-16 Friederike Grimmer; Lydie M. Dupont; Gerlinde Jung; Gerold Wefer
The Piacenzian (3.60–2.58 Ma) covers the last stage of the Neogene just before the Earth's climate turned from relatively stable warm conditions to the cooler climate with high amplitude glacial‐interglacial oscillations of the Pleistocene. Even during this period early fluctuations towards cooler conditions occurred, and sea surface temperature (SST) reconstructions show stepwise increasing gradients
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Drastic Vegetation Change in the Guajira Peninsula (Colombia) During the Neogene Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-16 Carlos Jaramillo; Pierre Sepulchre; Damian Cardenas; Alexander Correa‐Metrio; J. Enrique Moreno; Raul Trejos; Diego Vallejos; Natalia Hoyos; Camila Martínez; Daniella Carvalho; Jaime Escobar; Francisca Oboh‐Ikuenobe; Mercedes B. Prámparo; Diego Pinzón
Dry biomes occupy ~35% of the landscape in the Neotropics, but these are heavily human‐disturbed. In spite of their importance, we still do not fully understand their origins and how they are sustained. The Guajira Peninsula in northern Colombia is dominated by dry biomes and has a rich Neogene fossil record. Here, we have analyzed its changes in vegetation and precipitation during the Neogene using
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Issue Information Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-26
No abstract is available for this article.
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Stable Oxygen Isotope Composition Is Biased by Shell Calcification Intensity in Planktonic Foraminifera Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-17 M. F. G. Weinkauf; J. Groeneveld; J. J. Waniek; T. Vennemann; R. Martini
Planktonic Foraminifera are widely used for environmental reconstructions through measurements of their shell's geochemical characteristics, including its stable oxygen and carbon isotope composition. Using these parameters as unbiased proxies requires a firm knowledge of all potential confounding factors influencing foraminiferal shell geochemistry. One such parameter is the shell calcification intensity
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Plio‐Pleistocene Indonesian Throughflow Variability Drove Eastern Indian Ocean Sea Surface Temperatures Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-29 Rebecca A. Smith; Isla S. Castañeda; Jeroen Groeneveld; David De Vleeschouwer; Jorijntje Henderiks; Beth A. Christensen; Willem Renema; Gerald Auer; Kara Bogus; Stephen J. Gallagher; Craig S. Fulthorpe
Ocean gateways facilitate circulation between ocean basins, thereby impacting global climate. The Indonesian Gateway transports water from the Pacific to the Indian Ocean via the Indonesian Throughflow (ITF) and drives the strength and intensity of the modern Leeuwin Current, which carries warm equatorial waters along the western coast of Australia to higher latitudes. Therefore, ITF dynamics are a
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Issue Information Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-14
No abstract is available for this article.
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Silicon Isotopes in an EMIC's Ocean: Sensitivity to Runoff, Iron Supply, and Climate Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-14 H. Dietze; U. Löptien; R. Hordoir; M. Heinemann; W. Huiskamp; B. Schneider
The isotopic composition of Si in biogenic silica (BSi), such as opal buried in the oceans' sediments, has changed over time. Paleorecords suggest that the isotopic composition, described in terms of δ30Si, was generally much lower during glacial times than today. There is consensus that this variability is attributable to differing environmental conditions at the respective time of BSi production
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Development of a Correlated Fe‐Mn Crust Stratigraphy Using Pb and Nd Isotopes and Its Application to Paleoceanographic Reconstruction in the Atlantic Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-10-02 P. Josso; M. S. A. Horstwood; I. L. Millar; V. Pashley; P. A. J. Lusty; B. Murton
Eight ferromanganese crust samples spanning the complete depth range of Tropic Seamount in the northeast Atlantic were analyzed for Pb and Nd isotopes to reconstruct water mass origin and mixing over the last 75 Ma. Pb isotopes were determined by laser ablation multicollector inductively coupled plasma mass spectrometer (LA‐MC‐ICP‐MS), which enables the rapid production of large, high spatial resolution
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Bihemispheric Warming in the Miocene Climatic Optimum as Seen From the Danish North Sea Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-08-26 Timothy D. Herbert; Rebecca Rose; Karen Dybkjær; Erik S. Rasmussen; Kasia K. Śliwińska
The Miocene epoch witnessed major changes in climate. The marine oxygen isotope record, our best single continuous representation of the time interval, contains large shifts indicating substantial changes in the glaciation of Antarctica and/or deep ocean temperatures, with the interval of the most depleted isotopic composition occurring between ~18 and 13.9 Ma (mid‐Miocene Climatic Optimum [MCO]).
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Complex Interactions Between Large Igneous Province Emplacement and Global‐Temperature Changes During the Cenomanian‐Turonian Oceanic Anoxic Event (OAE 2) Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-26 L. M. E. Percival; N. A. G. M. van Helmond; D. Selby; S. Goderis; P. Claeys
Super greenhouse temperatures at the onset of the Cenomanian‐Turonian oceanic anoxic event (OAE 2) have been widely linked with large igneous province (LIP) volcanic activity. However, the extent to which volcanism influenced subsequent climate changes throughout OAE 2, such as global cooling during the Plenus Cold Event (PCE) early in the OAE, and the subsequent return to very warm conditions through
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A Warm, Stratified, and Restricted Labrador Sea Across the Middle Eocene and Its Climatic Optimum Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-02 Margot J. Cramwinckel; Helen K. Coxall; Kasia K. Śliwińska; Marcel Polling; Dustin T. Harper; Peter K. Bijl; Henk Brinkhuis; James S. Eldrett; Alexander J. P. Houben; Francien Peterse; Stefan Schouten; Gert‐Jan Reichart; James C. Zachos; Appy Sluijs
Several studies indicate that North Atlantic Deep Water (NADW) formation might have initiated during the globally warm Eocene (56–34 Ma). However, constraints on Eocene surface ocean conditions in source regions presently conducive to deep water formation are sparse. Here we test whether ocean conditions of the middle Eocene Labrador Sea might have allowed for deep water formation by applying (organic)
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Compound‐Specific Radiocarbon Analysis of (Sub‐)Antarctic Coastal Marine Sediments—Potential and Challenges for Chronologies Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-24 S. Berg; S. Jivcov; S. Kusch; G. Kuhn; L. Wacker; J. Rethemeyer
In Antarctic and Subantarctic environments, 14C‐based age determination is often challenging due to unknown reservoir effects, low organic carbon contents of sediments, and high contributions of petrogenic (14C‐free) carbon in ice marginal settings. In this study, we evaluate possible benefits and challenges of compound‐specific radiocarbon analysis (CSRA) as a tool for age determination of marine
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The Postglacial Isotopic Record of Intermediate Water Connects Mediterranean Sapropels and Organic‐Rich Layers Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-09 Alessandro Incarbona; Mario Sprovieri
Carbon‐rich layers exist at both sides of the Mediterranean Sea sedimentary record and are called sapropels and organic rich layers (ORLs), respectively, in the eastern and western basins. They have different levels of organic carbon accumulation and seafloor oxygen deprivation. The most recent sapropel and ORL depositions have a different timing, approximately 10.8–6.1 and 14.5–9.0 ka, respectively
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Mechanistic Insights Into Molecular Proxies Through Comparison of Subannually Resolved Sedimentary Records With Instrumental Water Column Data in the Santa Barbara Basin, Southern California Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-13 Susanne Alfken; Lars Wörmer; Julius S. Lipp; Jenny Wendt; Arndt Schimmelmann; Kai‐Uwe Hinrichs
Lipid biomarkers archived in marine sediments include widely applied proxies to reconstruct sea surface temperature (SST). Two prominent groups of SST sensitive biomarkers are long‐chain alkenones from haptophyte algae and glycerol dibiphytanyl glycerol tetraethers (GDGTs) from planktonic Thaumarchaeota. The corresponding proxies, and TEX86, respectively, are strongly correlated with mean annual SST
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The Benthic B/Ca Record at Site 806: New Constraints on the Temperature of the West Pacific Warm Pool and the “El Padre” State in the Pliocene Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-22 S. M. White; A. Christina Ravelo
The West Pacific Warm Pool (WPWP)'s response to increased pCO2 during the Pliocene is a key model validation target. Different temperature proxies show different trends: The foraminiferal Mg/Ca sea surface temperature (SST) record shows Pliocene WPWP temperatures ~1.2°C cooler than today (Wara et al., 2005, https://doi.org/10.1126/science.1112596), whereas a TEX86 study finds a cooling trend and claims
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The Brachiopod δ11B Record Across the Carboniferous‐Permian Climate Transition Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-12 S. A. Legett; E. T. Rasbury; E. L. Grossman; N. G. Hemming; D. E. Penman
We present the δ11B of well‐preserved brachiopod fossils coupled with geochemical modeling to examine how seawater boron responded to abrupt and dynamic climate changes in the Late Paleozoic. The Late Carboniferous, a time of major coal formation and glacioeustatic sea level changes, is characterized by relatively stable brachiopod δ11B of 15–17‰, similar to values seen in modern brachiopods. Brachiopod
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Climate‐Induced Variability in Mediterranean Outflow to the North Atlantic Ocean During the Late Pleistocene Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-08-24 Matthew D. Nichols; Chuang Xuan; Simon Crowhurst; David A. Hodell; Carl Richter; Gary D. Acton; Paul A. Wilson
Mediterranean Outflow Water (MOW) adds salt and density to open ocean intermediate waters and is therefore an important motor of Atlantic meridional overturning circulation (AMOC) and climate variability. However, the variability in strength and depth of MOW on geological timescales is poorly documented. Here we present new detailed records, with excellent age control, of MOW variability from 416 ka
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Variability of the Indian Monsoon in the Andaman Sea Across the Miocene‐Pliocene Transition Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-08 Janika Jöhnck; Wolfgang Kuhnt; Ann Holbourn; Nils Andersen
We reconstructed the variability of the Earth's strongest hydrological system, the Indian monsoon, over the interval 6.24 to 4.91 Ma at International Ocean Discovery Program (IODP) Expedition 353 Site U1448 in the Andaman Sea. We integrated high‐resolution benthic and planktic foraminiferal carbon and oxygen isotopes with Mg/Ca measurements of the mixed layer foraminifer Trilobatus sacculifer to reconstruct
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Abrupt Climate and Weather Changes Across Time Scales Paleoceanogr. Paleoclimatol. (IF 2.888) Pub Date : 2020-09-11 Gerrit Lohmann, Martin Butzin, Nina Eissner, Xiaoxu Shi, Christian Stepanek
The past provides evidence of abrupt climate shifts and changes in the frequency of climate and weather extremes. We explore the nonlinear response to orbital forcing and then consider climate millennial variability down to daily weather events. Orbital changes are translated into regional responses in temperature, where the precessional response is related to nonlinearities and seasonal biases in
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