Biogeochemical evolution and organic carbon deposition on the Northwestern European Shelf during the Toarcian Ocean Anoxic Event
"The Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) represents a well-known episode of organic-rich deposition, which is accompanied by a substantial negative carbon-isotope excursion (CIE). Underpinning the relationships between the carbon-cycle perturbation, ocean anoxia, primary productivity feedbacks and the enrichment of sedimentary organic carbon remains a major challenge. Here, we present high-resolution geochemical[...]"
Source: Science Direct
Authors: Alexander J.P.Houben et al.
Heavy iron in large gem diamonds traces deep subduction of serpentinized ocean floor
"Subducting tectonic plates carry water and other surficial components into Earth’s interior. Previous studies suggest that serpentinized peridotite is a key part of deep recycling, but this geochemical pathway has not been directly traced. Here, we report Fe-Ni–rich metallic inclusions in sublithospheric diamonds from a depth of 360 to 750 km with isotopically heavy iron (δ56Fe = 0.79 to 0.90‰) and unradiogenic osmium[...]"
Authors: Evan M. Smith et al.
Deoxygenation impacts on Baltic Sea cod: Dramatic declines in ecosystem services of an iconic keystone predator
"The intensified expansion of the Baltic Sea’s hypoxic zone has been proposed as one reason for the current poor status of cod (Gadus morhua) in the Baltic Sea, with repercussions throughout the food web and on ecosystem services. We examined the links between increased hypoxic areas and the decline in maximum length of Baltic cod, a demographic proxy for services[...]"
Authors: Alessandro Orio et al.
Global declines in coral reef calcium carbonate production under ocean acidification and warming
"Ocean warming and acidification threaten the future growth of coral reefs. This is because the calcifying coral reef taxa that construct the calcium carbonate frameworks and cement the reef together are highly sensitive to ocean warming and acidification. However, the global-scale effects of ocean warming and acidification on rates of coral reef net carbonate production remain poorly constrained despite a wealth of studies assessing their effects on the calcification of individual organisms[...]"
Source: PNAS- Proceedings of the National Academy of Sciences of the United States of America
Authors: Christopher E. Cornwall et al.
Effect of Resolving Ocean Eddies on the Transient Response of Global Mean Surface Temperature to Abrupt 4xCO2 Forcing
"The magnitude of global mean surface temperature (GMST) response to increasing atmospheric CO2 concentrations is affected by the efficiency of ocean heat uptake, which in turn can be affected by oceanic mesoscale eddies. Using the Max Planck Institute ‐ Earth System Model (MPI‐ESM1.2), we find that resolving eddies[...]"
Source: Advancing Earth and Space Science
Authors: D. A. Putrasahan et al.
A global viral oceanography database (gVOD)
"Virioplankton are a key component of the marine biosphere in maintaining diversity of microorganisms and stabilizing ecosystems. They also contribute greatly to nutrient cycles/cycling by releasing organic matter after lysis of hosts. In this study, we constructed the first global viral oceanography database (gVOD) by collecting 10 931 viral abundance (VA) data and 727 viral production (VP) data, along with host and relevant oceanographic parameters when available. Most VA data were obtained in the North Atlantic (32 %) and North Pacific (29 %) oceans, while the southeast Pacific[...]"
Source: Earth System Science Data
Authors: Le Xie et al.
Investigating the Roles of External Forcing and Ocean Circulation on the Atlantic Multidecadal SST Variability in a Large Ensemble Climate Model Hiera
"This paper attempts to enhance our understanding of the causes of Atlantic Multidecadal Variability, the AMV. Following the literature, we define the AMV as the SST averaged over the North Atlantic basin, linearly detrended and low-pass filtered. There is an ongoing debate about the drivers of the AMV, which include internal variability generated from the ocean or atmosphere (or both), and external radiative forcing. We test the role of these factors in explaining the time history, variance, and spatial pattern of the AMV using[...]"
Source: American Meteorological Soceity
Authors: Lisa N. Murphy et al.
Small phytoplankton contribute greatly to CO2-fixation after the diatom bloom in the Southern Ocean
"Phytoplankton is composed of a broad-sized spectrum of phylogenetically diverse microorganisms. Assessing CO2-fixation intra- and inter-group variability is crucial in understanding how the carbon pump functions, as each group of phytoplankton may be characterized by diverse efficiencies in carbon fixation and export to the deep ocean. We measured the CO2-fixation of different groups of phytoplankton at the single-cell level around the naturally iron-fertilized Kerguelen plateau (Southern Ocean)[...]"
Source: The ISME Journal
Authors: Solène Irion et al
A pole-to-equator ocean ousverturning circulation on Encelad
"Enceladus is believed to have a saltwater global ocean, heated at the ocean–core interface and losing heat to the floating ice shell above. This configuration suggests an important role for vertical convection. The ice shell has dramatic meridional thickness variations that, in steady state, must be sustained by the ocean circulation against processes acting to remove these anomalies. This could be achieved through spatially separated regions of freezing and melting at the ocean–ice interface. Here, we use an idealized[...]"
Source: Nature Geoscience
Authours: Ana H. Lobo et al.
Iron isotopes trace primordial magma ocean cumulates melting in Earth’s upper mantle
"The differentiation of Earth ~4.5 billion years (Ga) ago is believed to have culminated in magma ocean crystallization, crystal-liquid separation, and the formation of mineralogically distinct mantle reservoirs. However, the magma ocean model remains difficult to validate because of the scarcity of geochemical tracers of lower mantle mineralogy. The Fe isotope compositions (δ57Fe) of ancient mafic rocks can be used to reconstruct the mineralogy of their mantle source regions. We present Fe isotope data for 3.7-Ga metabasalts from the Isua Supracrustal Belt (Greenland). The δ57Fe signatures[...]"
Source: Science Advances
Authors: Helen M. Williams et al.