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.
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.
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.
Emerging Solutions to Return Nature to the Urban Ocean
"Urban and periurban ocean developments impact 1.5% of the global exclusive economic zones, and the demand for ocean space and resources is increasing. As we strive for a more sustainable future, it is imperative that we better design, manage, and conserve urban ocean spaces for both humans and nature. We identify three key objectives for more sustainable urban oceans: reduction of urban pressures, protection and restoration of ocean ecosystems, and support of critical ecosystem services. We describe an array of emerging evidence-based approaches, including greening grayinfrastructure, restoring habitats, and developing biotechnologies.
Source: ANNUAL REVIEWS
Authors: Laura Airoldi et al.
A benthic oxygen oasis in the early Neoproterozoic ocean
"Benthic oxygen oases linked to photosynthetic mats have been reported in modern anoxic aquatic systems. Benthic macroalgal blooms were common in stratified, anoxic Neoproterozoic oceans, leading us to hypothesize the existence of benthic oxygen oases at that time. This hypothesis has significant implications regarding the bioavailability of transition metals (e.g., Cu, Zn, Ni, Mo, V) and the distribution of aerobic eukaryotes in these oceans. However, little research has been directed toward testing the benthic oxygen[...]"
Source: Science Direct
Authors:Haiyang Wang et al.
Calibration of temperature-dependent ocean microbial processes in the cGENIE.muffin (v0.9.13) Earth system model
"Temperature is a master parameter in the marine carbon cycle, exerting a critical control on the rate of biological transformation of a variety of solid and dissolved reactants and substrates. Although in the construction of numerical models of marine carbon cycling, temperature has been long recognised as a key parameter in the production and export of organic matter at the ocean surface, its role in the ocean interior is much less frequently accounted for. There, bacteria (primarily) transform sinking particulate organic matter (POM) into its dissolved constituents and consume dissolved oxygen (and/or other electron acceptors such as sulfate). The nutrients and carbon[...]"
Source: EGU- European Geosciences Union
Authors: Katherine A. Crichton
Regional patterns and temporal evolution of ocean iron fertilization and CO2 drawdown during the last glacial termination
"The last time Earth's climate experienced geologically rapid global warming was associated with the last glacial termination, when atmospheric CO2 concentrations rose from 180 ppmv during the Last Glacial Maximum (LGM, 26-19 kaBP) to ∼260 ppmv by the early Holocene (12-8 kaBP). About one quarter of that difference is thought to be due to a stronger biological pump during glacial times, driven by increased aeolian dust deposition and hence greater iron availability in[...]"
Source: Science Direct
Authors: Fabrice Lambert et al.
Mixing by Oceanic Lee Waves
"Oceanic lee waves are generated in the deep stratified ocean by the flow of ocean currents over sea floor topography, and when they break, they can lead to mixing in the stably stratified ocean interior. While the theory of linear lee waves is well established, the nonlinear mechanisms leading to mixing are still under investigation. Tidally driven lee waves have long been observed in the ocean, along with associated mixing, but observations of lee waves forced by geostrophic eddies are relatively sparse and largely indirect[...]"
Source: Annual Reviews
Authors: Sonya Legg
Microbial niche differentiation explains nitrite oxidation in marine oxygen minimum zones
"Nitrite is a pivotal component of the marine nitrogen cycle. The fate of nitrite determines the loss or retention of fixed nitrogen, an essential nutrient for all organisms. Loss occurs via anaerobic nitrite reduction to gases during denitrification and anammox, while retention occurs via nitrite oxidation to nitrate. Nitrite oxidation is usually represented in biogeochemical models by one kinetic parameter and one oxygen threshold, below which nitrite oxidation is set to zero. Here we find that the responses of nitrite oxidation[...]"
Authors: Xin Sun et al.
Impact of mid-glacial ice sheets on deep ocean circulation and global climate
"This study explores the effect of southward expansion of Northern Hemisphere (American) mid-glacial ice sheets on the global climate and the Atlantic Meridional Overturning Circulation (AMOC) as well as the processes by which the ice sheets modify the AMOC. For this purpose, simulations of Marine Isotope Stage (MIS) 3 (36 ka) and 5a (80 ka) are performed with an atmosphere–ocean general circulation model. In the MIS3 and MIS5a simulations, the global average temperature decreases by 5.0 and 2.2 ∘C, respectively, compared with the preindustrial climate simulation. The AMOC weakens by 3 % in MIS3, whereas it strengthens[...]"
Source: EGU-European Geosciences Union
Authors: Sam Sherriff-Tadano et al.