Impact of Dust and Temperature on Primary Productivity in Late Miocene Oceans DOI Creative Commons
Quentin Pillot, Anta‐Clarisse Sarr, Yannick Donnadieu

et al.

Paleoceanography and Paleoclimatology, Journal Year: 2025, Volume and Issue: 40(1)

Published: Jan. 1, 2025

Abstract Most of the primary productivity in ocean comes from phytoplankton, and is impacted, among other things, by amount nutrients available, as well temperature. The Late Miocene Pliocene were marked global aridification, linked to emergence large deserts, likely increasing input dust thus into ocean. There was also a decrease temperature during this period, decline atmospheric CO 2 concentration. objective study explore sensitivity levels on oceans under boundary conditions. Here we used simulations performed with coupled ocean‐atmosphere model IPSL‐CM5A2 its marine biogeochemistry component PISCES paleogeography. Our results show that an increase produces quasi‐generalized productivity, associated nutrient limitation. This leads deficits some areas, such coastlines Eastern Equatorial Pacific. lower water temperatures lead reduction productivity. mainly due supply resulting less intense remineralization. In addition, our change carbon export are highly heterogeneous spatially. Simulations combined sedimentary data suggesting link between cooling Biogenic Bloom Pliocene.

Language: Английский

A Model Based Study of the Emergence of North Atlantic Deep Water During the Cenozoic: A Tale of Geological and Climatic Forcings DOI Creative Commons
Erwan Pineau, Yannick Donnadieu, Pierre Maffre

et al.

Paleoceanography and Paleoclimatology, Journal Year: 2025, Volume and Issue: 40(5)

Published: May 1, 2025

Abstract The North Atlantic Deep Water (NADW) is a key component of modern climate systems, redistributing heat from equatorial to polar regions and contributing the Meridional Overturning Circulation. However, timing its emergence mechanisms driving formation remain uncertain. This study explores ocean circulation patterns during middle Eocene (48–38 Ma) early Miocene (23–16 using simulations with IPSL‐CM5A2 model. In simulations, reduced surface salinity in prevents NADW formation, regardless atmospheric levels or presence an Antarctic ice sheet. Conversely, suggest that paleogeographic shifts promote higher salinity, enabling formation. Specifically, closure Polish Strait narrowing Central American Seaway enhance salt retention increase transport subtropical subpolar regions. Additionally, changes African monsoonal precipitation—characterized by reduction eastward shift across Africa—reduce freshwater influx into between Miocene. These combined factors weaken stratification, facilitating development research provides timeline for initiation insights processes

Language: Английский

Citations

0
Vegetation feedbacks accelerated the late Miocene climate transition DOI Creative Commons
Ran Zhang, Jiaqi Guo, Catherine P. Bradshaw

et al.

Science Advances, Journal Year: 2025, Volume and Issue: 11(18)

Published: May 2, 2025

The late Miocene was an important stage for the formation of modern-like ecological and environmental patterns. Proxy data from middle to reveal that large-scale cooling drying occurred; however, reasons this climate transition remain unclear. Through a compilation proxy simulations, our results indicate atmospheric CO 2 decline markedly decreased temperature reduced precipitation in most land area, while paleogeographic changes enhanced at northern high latitudes increased East Asia, Africa, South America. In comparison, vegetation accelerated (the maximum exceeded 10°C) modulated low- mid-latitude continents decrease close 30%). This deepens understanding mechanism highlights importance feedbacks during global change.

Language: Английский

Citations

0
Climate variability, heat distribution, and polar amplification in the warm unipolar “icehouse” of the Oligocene DOI Creative Commons
Dominique Jenny, Tammo Reichgelt, Charlotte L. O’Brien

et al.

Climate of the past, Journal Year: 2024, Volume and Issue: 20(7), P. 1627 - 1657

Published: July 25, 2024

Abstract. The Oligocene (33.9–23.03 Ma) had warm climates with flattened meridional temperature gradients, while Antarctica retained a significant cryosphere. These may pose imperfect analogues to distant future climate states unipolar icehouse conditions. Although local and regional environmental reconstructions of conditions are available, the community lacks synthesis reconstructions. To provide comprehensive overview marine terrestrial in Oligocene, reconstruction trends through time, we review proxy records compare these numerical model simulations Oligocene. Results, based on present relatively sparse data, suggest temperatures around Equator that similar modern temperatures. Sea surface (SSTs) show patterns land temperatures, at mid- high latitudes (∼60–90°), especially Southern Hemisphere (SH). Vegetation-based precipitation regionally drier compared times Equator. When overestimate most areas, particularly tropics. Temperatures generally underestimated models data tend warming In line previous proxy-to-model comparisons, find underestimate polar amplification Equator-to-pole gradient suggested from available data. This further stresses urgency solving this widely recorded problem for past climates, such as

Language: Английский

Citations

3
Eocene maar sediments record warming of up to 3.5 °C during a hyperthermal event 47.2 million years ago DOI Creative Commons
Clemens Schmitt, Iuliana Vasiliev, Niels Meijer

et al.

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: Aug. 29, 2024

Abstract Eocene hyperthermal events reflect profound perturbations of the global carbon cycle. Most our knowledge about their onset, timing, and rates originates from marine records. Hence, pacing magnitude continental warming remains largely unaccounted for due to a lack high-resolution climate Here we use terrestrial biomarkers isotopes retrieved varved lake deposits UNESCO World Heritage site ‘Messel Fossil Pit’ (Germany) quantify sub-millennial millennial-scale temperature isotope changes across event C21n-H1 (47.2 million years ago). Our results show maximum ca. 3.5 °C during C21n-H1. We propose that two components are responsible pattern hyperthermal: (1) massive release greenhouse gases into atmosphere-ocean system (2) half-precession orbital forcing indicated by ~12.000-year cycles. The record bulk organic matter indicates sharp, 7‰ decrease at peak hyperthermal, corresponding increased content shift in algal community. Collectively, proxy data reveal structure response is characterized overall with superimposed sub-orbital scale fluctuations.

Language: Английский

Citations

3
Impact of Dust and Temperature on Primary Productivity in Late Miocene Oceans DOI Creative Commons
Quentin Pillot, Anta‐Clarisse Sarr, Yannick Donnadieu

et al.

Paleoceanography and Paleoclimatology, Journal Year: 2025, Volume and Issue: 40(1)

Published: Jan. 1, 2025

Abstract Most of the primary productivity in ocean comes from phytoplankton, and is impacted, among other things, by amount nutrients available, as well temperature. The Late Miocene Pliocene were marked global aridification, linked to emergence large deserts, likely increasing input dust thus into ocean. There was also a decrease temperature during this period, decline atmospheric CO 2 concentration. objective study explore sensitivity levels on oceans under boundary conditions. Here we used simulations performed with coupled ocean‐atmosphere model IPSL‐CM5A2 its marine biogeochemistry component PISCES paleogeography. Our results show that an increase produces quasi‐generalized productivity, associated nutrient limitation. This leads deficits some areas, such coastlines Eastern Equatorial Pacific. lower water temperatures lead reduction productivity. mainly due supply resulting less intense remineralization. In addition, our change carbon export are highly heterogeneous spatially. Simulations combined sedimentary data suggesting link between cooling Biogenic Bloom Pliocene.

Language: Английский

Citations

0