• Issue

    Paleoceanography and Paleoclimatology: Volume 38, Issue 8

    August 2023

Issue Information

Free Access

Issue Information

  • First Published: 08 August 2023

Research Article

The Nature of Opal Burial in the Equatorial Atlantic During the Deglaciation

  • First Published: 04 August 2023
Key Points

  • Microfossil evidence for the contribution by Si-rich southern-sourced water to enhanced primary productivity in the equatorial Atlantic

  • The position of the intertropical convergence zone plays a role in determining the different productivity conditions

  • Opal accumulation does not necessarily reflect solely diatom burial

Open Access

Meridional Heat Transport in the DeepMIP Eocene Ensemble: Non-CO2 and CO2 Effects

  • First Published: 03 August 2023
Key Points

  • The latent heat transport of the monsoon increases through the Eocene higher CO2 concentration, but it is reduced by the Eocene topography

  • The poleward heat transport of midlatitude cyclones is higher in the Northern Hemisphere in the Eocene, due to the different topography

  • The Eocene northern Hadley cell circulates more heat, than in the present, while its net poleward heat transport is even less than today

Open Access

Planktic Foraminiferal Resilience to Environmental Change Associated With the PETM

  • First Published: 07 August 2023
Key Points

  • No substantial change in planktic foraminiferal carbonate production (size-normalized weight, test size, or abundance) during the Palaeocene-Eocene Thermal Maximum

  • Sea surface warming and the resulting migration of taxa increased carbonate production in the Southern Ocean

  • Pelagic carbonate composition changes due to differing impacts on foraminifers and coccolithophores which we link to nutrient availability

Open Access

Development of a Deep-Water Carbonate Ion Concentration Proxy Based on Preservation of Planktonic Foraminifera Shells Quantified by X-Ray CT Scanning

  • First Published: 09 August 2023
Key Points

  • Planktonic foraminiferal shell dissolution intensity was determined by Computed Tomography (CT)-based proxy using core top samples in the Southern Atlantic Ocean

  • The characteristics and reliability of CT-based proxy were compared with conventional proxy

  • The CT-based proxy is available for reconstructing deep seawater carbonate ion concentration under the appropriate condition

Open Access

Climate Induced Thermocline Aging and Ventilation in the Eastern Atlantic Over the Last 32,000 Years

  • First Published: 06 August 2023
Key Points

  • North Atlantic cold-water corals trace well-ventilated thermocline waters near major oceanic fronts since the Last Glacial Maximum

  • Across the South Atlantic into the Southern Ocean, aged waters with large variability and connectivity are evident during the last glacial

  • The modern state of radiocarbon ventilation of the thermocline Atlantic is initiated during the Younger Dryas cold reversal

Commentary

Free Access

Chasing Interannual Marine Paleovariability

  • First Published: 13 August 2023
Key Points

  • We briefly recount how scientists have reconstructed past year-to-year variations in marine temperatures

Research Article

Open Access

Transient Deep Ocean Cooling in the Eastern Equatorial Pacific Ocean at the Eocene-Oligocene Transition

  • First Published: 14 August 2023
Key Points

  • Benthic foraminiferal clumped isotope thermometry is used to reconstruct deep-sea temperatures at the Eocene-Oligocene Transition

  • The onset of large-scale Antarctic glaciation is associated with an abrupt ∼5°C cooling of the deep eastern equatorial Pacific Ocean

  • This cooling is short-lived suggesting Antarctic glaciation did not have a long-term impact on deep-sea temperatures in the Pacific Ocean

Open Access

A Comparison Study of Mg/Ca-, Alkenone-, and TEX86-Derived Temperatures for the Brazilian Margin

  • First Published: 13 August 2023
Key Points

  • Parallel Mg/Ca (Globigerinoides ruber), alkenone and TEX86-based temperature estimates in the western tropical South Atlantic (WTSA) across Marine Isotope Stages (MIS) 6–5

  • Mg/Ca and alkenones represent annual mean sea surface temperatures, but most TEX86-based temperatures deviate to colder values

  • Anomalous sea surface warming in the WTSA during late MIS 6 appears as a robust signal

Open Access

High Productivity at High Latitudes? Photosynthesis and Leaf Ecophysiology in Arctic Forests of the Eocene

  • First Published: 13 August 2023
Key Points

  • Lush forests thrived in the Arctic during the Eocene under non-analogous climatic conditions

  • Tree productivity of Eocene forests was studied for two exemplary fossil Arctic sites based on a photosynthesis model

  • Compared to extant deciduous forests, productivity of Arctic Eocene forests was in the range of modern tropical forests