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.
Current Atlantic Meridional Overturning Circulation weakest in last millennium
"The Atlantic Meridional Overturning Circulation (AMOC)—one of Earth’s major ocean circulation systems—redistributes heat on our planet and has a major impact on climate. Here, we compare a variety of published proxy records to reconstruct the evolution of the AMOC since about AD 400. A fairly consistent picture of the AMOC emerges: after a long and relatively stable period, there was an initial weakening starting in the nineteenth century, followed by a second, more rapid, decline in the mid-twentieth[...]"
Source: Nature Geosciences
Authors: L. Caesar et al.
Pervasive distribution of polyester fibres in the Arctic Ocean is driven by Atlantic inputs
"Microplastics are increasingly recognized as ubiquitous global contaminants, but questions linger regarding their source, transport and fate. We document the widespread distribution of microplastics in near-surface seawater from 71 stations across the European and North American Arctic - including the North Pole. We also characterize samples to a depth of 1,015 m in the Beaufort Sea. Particle abundance correlated with longitude, with almost three times more particles in the eastern Arctic compared to the west. Polyester comprised[...]"
Source: Nature Communications
Authors: Peter S. Ross et al.
Gulf of Mexico blue hole harbors high levels of novel microbial lineages
"Exploration of oxygen-depleted marine environments has consistently revealed novel microbial taxa and metabolic capabilities that expand our understanding of microbial evolution and ecology. Marine blue holes are shallow karst formations characterized by low oxygen and high organic matter content. They are logistically challenging to sample, and thus our understanding of their biogeochemistry and microbial ecology is limited. We present a metagenomic and geochemical characterization of Amberjack Hole on the Florida continental shelf (Gulf of Mexico). Dissolved oxygen became depleted at the hole’s rim[...]"
Source: The ISME Journal
Authors: N. V. Patin 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.
An integrated framework for lean manufacturing in relation with blue ocean manufacturing - A case study
"Lean Manufacturing (LM) has traditionally helped industries in removing the non-value-added processes to achieve operational excellence. Similarly, the blue ocean strategy helps organizations in creating an uncontested market space where the competition is irrelevant. The authors posit that the integration of two approaches helps in achieving holistic manufacturing excellence, and there is a paucity of approaches that integrate the two paradigms. In order to fill this research gap, the authors have developed an integrated framework that combines the concepts of lean[...]"
Source: Science Direct
Authors: Saba Sadiq et al.
Stable isotopic composition of top consumers in Arctic cryoconite holes: revealing divergent roles in a supraglacial trophic network
"Arctic cryoconite holes represent highly biologically active aquatic habitats on the glacier surface characterized by the dynamic nature of their formation and functioning. The most common cryoconite apex consumers are the cosmopolitan invertebrates – tardigrades and rotifers. Several studies have highlighted the potential relevance of tardigrades and rotifers to cryoconite holes' ecosystem functioning. However, due to the dominant occurrence of prokaryotes, these consumers are usually out of the major scope of most studies aimed at understanding biological processes on glaciers. The aim of this descriptive study is to present pioneering[...]"
Authors: Tereza Novotná Jaroměřská et al.
Protecting the global ocean biodiversity, food and climate
"The ocean contains unique biodiversity, provides valuable food resources and is a major sink for anthropogenic carbon. Marine protected areas (MPAs) are an effective tool for restoring ocean biodiversity and ecosystem services1,2, but at present only 2.7% of the ocean is highly protected3. This low level of ocean protection is due largely to conflicts with fisheries and other extractive uses. To address this issue, here we developed a conservation planning framework to prioritize highly protected MPAs in places that would result in multiple benefits today and in the future. We find that a substantial increase in ocean protection could have triple benefits, by protecting biodiversity[...]"
Authors: Enric Sala et al.
Climate field completion via Markov random fields – Application to the HadCRUT4.6 temperature dataset
"Surface temperature is a vital metric of Earth’s climate state, but is incompletely observed in both space and time: over half of monthly values are missing from the widely used HadCRUT4.6 global surface temperature dataset. Here we apply GraphEM, a recently developed imputation method, to construct a spatially complete estimate of HadCRUT4.6 temperatures. GraphEM leverages Gaussian Markov random fields (aka Gaussian graphical models) to better estimate covariance relationships within a climate field, detecting anisotropic features such as land/ocean contrasts, orography, ocean currents and wave-propagation pathways.[...]"
Source: AMS- American Meteorological Society
Authors: Adam Vaccaro et al.
Role of tide-induced vertical mixing in the deep Pacific Ocean circulation
"We investigate the control mechanisms of the deep Pacific Ocean circulation by introducing updated methods for parameterizing tidal mixing. The column-integrated rates of dissipation in near- and far-fields are derived from the tidal energy conversion and dissipation rates estimated by a high resolution tide model. In the calculation of the far-field mixing, its dependency on stratification is taken into account based on theoretical and observational knowledge.Unlike previous studies that did not take the stratification dependence into account, the far-field mixing does not function to significantly enhance the deep Pacific Ocean circulation. The deep Pacific Ocean circulation is also found to be insensitive to the decay scale height of the near-field mixing. However, these factors affect the reproducibility of the[...]"
Source: Journal of Oceanography
Authors: Takao Kawasaki et al.