scholarly journals Global variability in seawater Mg:Ca and Sr:Ca ratios in the modern ocean

2020 ◽  
Vol 117 (36) ◽  
pp. 22281-22292 ◽  
Author(s):  
Mario Lebrato ◽  
Dieter Garbe-Schönberg ◽  
Marius N. Müller ◽  
Sonia Blanco-Ameijeiras ◽  
Richard A. Feely ◽  
...  
Keyword(s):  
International Association ◽  
Open Ocean ◽  
Total Alkalinity ◽  
Polar Regions ◽  
Marine Environments ◽  
Physical Sciences ◽  
Seawater Chemistry ◽  
Sr:Ca Ratios ◽  
Biogeochemical Parameters ◽  
Dynamic Exchange

Seawater Mg:Ca and Sr:Ca ratios are biogeochemical parameters reflecting the Earth–ocean–atmosphere dynamic exchange of elements. The ratios’ dependence on the environment and organisms' biology facilitates their application in marine sciences. Here, we present a measured single-laboratory dataset, combined with previous data, to test the assumption of limited seawater Mg:Ca and Sr:Ca variability across marine environments globally. High variability was found in open-ocean upwelling and polar regions, shelves/neritic and river-influenced areas, where seawater Mg:Ca and Sr:Ca ratios range from ∼4.40 to 6.40 mmol:mol and ∼6.95 to 9.80 mmol:mol, respectively. Open-ocean seawater Mg:Ca is semiconservative (∼4.90 to 5.30 mol:mol), while Sr:Ca is more variable and nonconservative (∼7.70 to 8.80 mmol:mol); both ratios are nonconservative in coastal seas. Further, the Ca, Mg, and Sr elemental fluxes are connected to large total alkalinity deviations from International Association for the Physical Sciences of the Oceans (IAPSO) standard values. Because there is significant modern seawater Mg:Ca and Sr:Ca ratios variability across marine environments we cannot absolutely assume that fossil archives using taxa-specific proxies reflect true global seawater chemistry but rather taxa- and process-specific ecosystem variations, reflecting regional conditions. This variability could reconcile secular seawater Mg:Ca and Sr:Ca ratio reconstructions using different taxa and techniques by assuming an error of 1 to 1.50 mol:mol, and 1 to 1.90 mmol:mol, respectively. The modern ratios’ variability is similar to the reconstructed rise over 20 Ma (Neogene Period), nurturing the question of seminonconservative behavior of Ca, Mg, and Sr over modern Earth geological history with an overlooked environmental effect.

scholarly journals New Approaches for the Observation of Transient Phenomena in Critical Marine Environment

2021 ◽  
Vol 9 (6) ◽  
pp. 578
Author(s):  
Roberta Ferretti ◽  
Massimo Caccia ◽  
Massimo Coltorti ◽  
Roberta Ivaldi
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Marine Environments ◽  
Transient Phenomena ◽  
New Approaches ◽  
Marine Vehicles ◽  
New Methodologies ◽  
Biogeochemical Parameters ◽  
Very High

This paper focuses on the development of new approaches to observe transient phenomena in critical marine environments using autonomous marine vehicles (AMVs) for the acquisition of physical and biogeochemical parameters of water and seabed characterization. The connection with metrological principles, together with the adoption of observing methodologies adjustable according to the specific marine environment being studied, allows researchers to obtain results that are reliable, reproducible, and comparable with those obtained through the classic monitoring methodologies. Tests were executed in dramatically dynamic, sensitive, and fragile areas, where the study and application of new methodologies is required to observe phenomena strongly localized in space and requiring very high resolutions, in time. Moreover, the harsh environmental conditions may present risks not only for the quality and quantity of the acquired data but also for the instrumentation and the operators. This is the case, for instance, in polar marine environments in proximity of tidal glaciers and in the Mediterranean Sea in areas characterized by seabed degassing activities, where AMV-supported monitoring procedures can allow for the safe observation of not repeatable and not completely predictable events.

scholarly journals TO THE 75th ANNIVERSARY OF E.G. Morozov

2021 ◽  
Vol 49 (2) ◽  
pp. 155-163
Author(s):  
S. M. Shapovalov
Keyword(s):  
Internal Waves ◽  
Executive Committee ◽  
International Association ◽  
World Ocean ◽  
Hydrological Processes ◽  
The Arctic ◽  
Physical Sciences ◽  
Russian Academy Of Sciences ◽  
Wide Range ◽  
Academy Of Sciences

March 15, 2021 Chief Researcher, Head of the Laboratory of Hydrological Processes of the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences, DSc, ex-president of the International Association for Physical Ocean Sciences (IAPSO) Evgeny Morozov is 75 years old. E.G. Morozov is a prominent scientist and organizer of world-class science in the field of studying the temporal and spatial variability of hydrological processes and internal waves in a wide range of scales. He was the first to build a map of the amplitudes of tidal internal waves of the World Ocean. His monograph “Oceanic Internal Waves” published in 1985 in Russian, as well as his article “Semidiurnal internal wave global field”, published in the Deep Sea Research in 1995, are among the most cited on the problem of internal tidal waves. Unique results were obtained by E.G. Morozov in the study of internal waves in the Arctic, including under the ice and near the front of glaciers sliding into the ocean on Spitsbergen. He made a significant contribution to the study of various currents: the Gulf Stream, the Kuroshio and their rings, the Antarctic Circumpolar Current, the California Current, the Falkland Current, the Lomonosov and Tareev subsurface equatorial currents. Since 1999 he has been a member of the Executive Committee of the International Association for the Physical Sciences of the Ocean (IAPSO) and since 2011 he has been elected President of the IAPSO, represented the IAPSO in this capacity on the Executive Committee of the International Geodetic and Geophysical Union (IUGG) and on the Executive Committee of the Scientific Committee on Oceanic research (SCOR). E.G. Morozov is the chairman of the Ocean Physical Sciences Section of the National Geophysical Committee of the Russian Academy of Sciences.

Small-Scale Gradients in Big River: Implications for a State-of-the-Art Research Platform in the Elbe

2021 ◽  
Author(s):  
Sina Bold ◽  
Justus E.E. van Beusekom ◽  
Yoana G. Voynova ◽  
Marius Cysewski ◽  
Bryce Van Dam ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Ammonium Phosphate ◽  
Total Alkalinity ◽  
Small Scale ◽  
Suspended Particulate ◽  
Research Platform ◽  
Biogeochemical Parameters ◽  
Art Research ◽  
Set Up

<p>Estuaries are crucial in transforming matter fluxes from land to sea. To better understand and quantify these processes and respective fluxes, it is important to determine the input into an estuary accurately. To allow for such studies in the Elbe estuary in Germany, a state-of-the-art research platform is currently being set-up just upstream of the weir in Geesthacht at the entrance of the estuary. Here, we report on small-scale spatial dynamics of organic matter and associated processes from several cross and longitudinal profiles around the planned location and the implications for the set-up of the aforementioned research platform.</p><p>Based on preliminary data obtained in August 2020 during a period of relatively low discharge, we present the following results: (1) In three cross profiles along a 10 km transect of the Elbe upstream of the weir, we observed considerable small-scale gradients regarding currents and various biogeochemical parameters. In comparison to the fairway, water from the riverbanks was depleted in suspended particulate matter, chlorophyll a, dissolved oxygen, and nitrate, and enhanced in ammonium, phosphate and silicate, as well as total alkalinity and dissolved inorganic carbon paralleled by decreasing pH. This suggests that in the summer, organic matter is deposited and remineralised at the riverbanks, resulting in the release of ammonium, phosphate and silicate, and in the removal of nitrate, presumably by denitrification. (2) Along the 10 km transect towards the weir, we observed that concentrations of suspended particulate matter, chlorophyll a, dissolved oxygen, nitrate and pH were decreasing. In contrast, we found that ammonium, phosphate and silicate, total alkalinity and dissolved inorganic carbon increased towards the weir. This suggests an increased sedimentation and subsequent remineralisation due to the reduced flow velocities in front of the weir. (3) An analysis of a 10-year time series from the weir supports this by showing higher ammonium concentrations when discharges were relatively low. The implications of these findings for the set-up of the research platform in this area, as well as for optimising estimates of budgets are discussed. The research platform will contribute to understand further such variations in biogeochemical parameters at the entrance of the Elbe estuary over time.</p><p>The research platform is set-up in cooperation with the Helmholtz initiative MOSES (“Modular Observation Solutions for Earth Systems“) and will be incorporated in the Elbe-North Sea Supersite of DANUBIUS-RI (“International Centre for Advanced Studies on River-Sea Systems“). Funding is provided by European Regional Development Funds, the federal state of Schleswig-Holstein, the Helmholtz Association and the Helmholtz-Zentrum Geesthacht. The research platform, planned to be operational in autumn 2021, will also be open for users e.g. to develop and test new methods and technologies. Data will be made available through the “Helmholtz Coastal Data Centre” (HCDC).</p>

Combination Service for Time-variable Gravity Field Solutions (COST-G) – GRACE-FO operational combination

2020 ◽  
Author(s):  
Ulrich Meyer ◽  
Martin Lasser ◽  
Adrian Jäggi ◽  
Frank Flechtner ◽  
Christoph Dahle ◽  
...  
Keyword(s):  
Time Series ◽  
Quality Control ◽  
International Association ◽  
Time Variable ◽  
Polar Regions ◽  
Time Variable Gravity ◽  
Gravity Fields ◽  
River Hydrology ◽  
Variable Gravity ◽  
Combined Time Series

<p lang="en-US">We present the operational GRACE-FO combined time-series of monthly gravity fields of the Combination Service for Time-variable Gravity fields (COST-G) of the International Association of Geodesy (IAG). COST-G_GRACE-FO_RL01_operational is combined at AIUB and relies on operational monthly solutions of the COST-G Analysis Centers GFZ, GRGS, IfG, LUH and AIUB and the associated Analysis Centers CSR and JPL. All COST-G Analysis Centers have passed a benchmark test to ensure consistency between the different processing approaches and all of the contributing time-series undergo a strict quality control focusing on the signal content in river basins and polar regions with pronounced changes in ice mass to uncover any regularization that may bias the combination.</p> <p lang="en-US">The combination is performed by variance component estimation on the solution level, the relative monthly weights thus providing valuable and independent insight into the consistency and noise levels of the individual monthly contributions. The combined products then are validated internally in terms of noise, approximated by the non-secular, non-seasonal variability over the oceans. Once they have passed this quality control the combined gravity fields are assessed by an external board of experts who evaluate them in terms of orbit predictions, lake altimetry, river hydrology or oceanography.</p>

scholarly journals Labile trace metal concentration measurements in marine environments: From coastal to open ocean areas

2019 ◽  
Vol 116 ◽  
pp. 92-101 ◽  
Author(s):  
Yue Gao ◽  
Chunyang Zhou ◽  
Camille Gaulier ◽  
Arne Bratkic ◽  
Josep Galceran ◽  
...  
Keyword(s):  
Trace Metal ◽  
Metal Concentration ◽  
Open Ocean ◽  
Trace Metal Concentration ◽  
Marine Environments ◽  
Concentration Measurements

scholarly journals Geochemical Features of Redox-Sensitive Trace Metals in Sediments under Oxygen-Depleted Marine Environments

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1021
Author(s):  
Moei Yano ◽  
Kazutaka Yasukawa ◽  
Kentaro Nakamura ◽  
Minoru Ikehara ◽  
Yasuhiro Kato
Keyword(s):  
Sedimentary Environment ◽  
Organic Matter Content ◽  
Oxygen Depletion ◽  
Major And Trace Elements ◽  
Matter Content ◽  
Open Ocean ◽  
Chemical Compositions ◽  
Marine Environments ◽  
High Productivity ◽  
Sedimentary Environments

Organic- and sulfide-rich sediments have formed in oxygen-depleted environments throughout Earth’s history. The fact that they are generally enriched in redox-sensitive elements reflects the sedimentary environment at the time of deposition. Although the modern ocean is well oxidized, oxygen depletion occurs in certain areas such as restricted basins and high-productivity zones. We measured bulk chemical compositions (major and trace elements, total organic carbon, and total sulfur) of organic- and sulfide-rich sediments collected from eight areas having oxygen-depleted water to discuss relationships between geochemical features and sedimentary environments. Major elemental compositions generally show mixtures of terrigenous detritus and biogenic carbonate. Some redox-sensitive elements might be controlled by organic matter content, whereas others could be contained in sulfide minerals in sediments. In particular, Mo and U show a characteristic trend; areas with higher Mo and U—at least partially owing to a depositional process called the “particulate shuttle”—generally correspond to regions influenced by the open ocean. In contrast, areas with lower Mo and U are more restricted marine environments. This suggests that the degree of Mo and U enrichment reflects the geography in terms of proximity to the open ocean, or the degree of the supply of these elements from the open ocean.

Environmental impacts of brass mesh nets on open ocean aquaculture pens in tropical marine environments

Aquaculture ◽  
2020 ◽  
Vol 524 ◽  
pp. 735266
Author(s):  
Tyler Sclodnick ◽  
Steve Sutton ◽  
Thomas Selby ◽  
Robert Dwyer ◽  
Langley Gace
Keyword(s):  
Environmental Impacts ◽  
Open Ocean ◽  
Marine Environments ◽  
Open Ocean Aquaculture

scholarly journals Numerical implementation and oceanographic application of the thermodynamic potentials of liquid water, water vapour, ice, seawater and humid air – Part 2: The library routines

Ocean Science ◽  
2010 ◽  
Vol 6 (3) ◽  
pp. 695-718 ◽  
Author(s):  
D. G. Wright ◽  
R. Feistel ◽  
J. H. Reissmann ◽  
K. Miyagawa ◽  
D. R. Jackett ◽  
...  
Keyword(s):  
Equation Of State ◽  
Web Site ◽  
International Association ◽  
Companion Paper ◽  
Physical Sciences ◽  
Humid Air ◽  
Water Ice ◽  
Cultural Organization ◽  
New Methods ◽  
Thermodynamic Potentials

Abstract. The SCOR/IAPSO1 Working Group 127 on Thermodynamics and Equation of State of Seawater has prepared recommendations for new methods and algorithms for numerical estimation of the the thermophysical properties of seawater. As an outcome of this work, a new International Thermodynamic Equation of Seawater (TEOS–10) was endorsed by IOC/UNESCO2 in June 2009 as the official replacement and extension of the 1980 International Equation of State, EOS-80. As part of this new standard a source code package has been prepared that is now made freely available to users via the World Wide Web. This package includes two libraries referred to as the SIA (Sea-Ice-Air) library and the GSW (Gibbs SeaWater) library. Information on the GSW library may be found on the TEOS-10 web site (http://www.TEOS-10.org). This publication provides an introduction to the SIA library which contains routines to calculate various thermodynamic properties as discussed in the companion paper. The SIA library is very comprehensive, including routines to deal with fluid water, ice, seawater and humid air as well as equilibrium states involving various combinations of these, with equivalent code developed in different languages. The code is hierachically structured in modules that support (i) almost unlimited extension with respect to additional properties or relations, (ii) an extraction of self-contained sub-libraries, (iii) separate updating of the empirical thermodynamic potentials, and (iv) code verification on different platforms and between different languages. Error trapping is implemented to identify when one or more of the primary routines are accessed significantly beyond their established range of validity. The initial version of the SIA library is available in Visual Basic and FORTRAN as a supplement to this publication and updates will be maintained on the TEOS-10 web site. 1SCOR/IAPSO: Scientific Committee on Oceanic Research/International Association for the Physical Sciences of the Oceans 2IOC/UNESCO: Intergovernmental Oceanographic Commission/United Nations Educational, Scientific and Cultural Organization

scholarly journals Géomorphologie : géographie globale – géographie totale – associations internationales

2005 ◽  
Vol 8 (16) ◽  
pp. 199-218 ◽  
Author(s):  
Louis-Edmond Hamelin
Keyword(s):  
United States ◽  
Subject Matter ◽  
International Association ◽  
The United States ◽  
Physical Sciences ◽  
Geographical Union ◽  
International Geographical ◽  
The Earth ◽  
The Subject ◽  
Made In

The great advances that geomorphology has made in recent years make necessary a critical re-examination of the relationships between this science and the field of geography. Is geomorphology truly geographical ? And if not, how can it become so ? Geomorphology has its roots in geology and was, of course, not designed to meet the specific needs of geographers. Under the leadership of W. M. Davis, geographers eventually adopted the study of geomorphology but did Utile to adapt it to particular purposes of their discipline. Most geographers can never aspire to true excellence in geomorphology because of their generally inadequate training in the physical sciences. We have found that most geographers tend to fall into one of four groups : 1. Those who consider themselves to be geomorphologists (about one-fourth of all geographers) ; 2. Those who just try to be informed in geomorphology ; 3. Those who ignore the existence of geomorphology ; 4. The « complete » geographer who practices a « functional » geomorphology. It also appears that the majority of geographers do not consider land-man relations to be their principal field of interest. The definition that we as geographers give to geography tends to sanction the kind of geography that we are capable of doing. For example, the classical géographie globale, which is characterized by an explanatory description of a complex of physical and human eclectic elements, does not normally require either a « complete » or a genetic geomorphology ; also, complex techniques of geomorphological investigation are not essential. Of greater importance is a geomorphology'-which is functional to geography and which will help us to understand better man's distribution and activities on the surface of the earth. This partial or « functional » geomorphology has achieved its greatest development in France (as an integral part of géographie globale) and is practised by a large number of geographers. Géographie totale, an expression which refers more to the subject matter of this geography than to its methodology, is an ensemble of specialized yet inter-related disciplines (one of which is geomorphology). This pluralistic geography daims many more adherents than does géographie globale. Géographie totale allows us to study all aspects of what is now called geomorphology (but which may eventually be termed « cosmomorphology  »). This new geomorphology is based on geophysical laws and is strictly quantitative. It is an integral part of the physical sciences but this does not mean that it is automatically divorced from man. Scientists of both the United States and the U. S. S. R. are actively engaged in this new geomorphology. We believe that it would be mutually advantageous for both the « functional » and the « complete » geomorphologists to group themselves into a new international association. To achieve this end we urge that the structures of the international Geographical Union be modified or that an « International Association of Geomorphology » be founded.

scholarly journals A mathematical modelling of bloom of the coccolithophore <i>Emiliania huxleyi</i> in a mesocosm experiment

2008 ◽  
Vol 5 (1) ◽  
pp. 787-840 ◽  
Author(s):  
P. Joassin ◽  
B. Delille ◽  
K. Soetaert ◽  
A. V. Borges ◽  
L. Chou ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dynamic Model ◽  
Dissolved Inorganic Carbon ◽  
Algal Growth ◽  
Emiliania Huxleyi ◽  
Mesocosm Experiment ◽  
Total Alkalinity ◽  
Viral Lysis ◽  
Nitrogen And Phosphorus ◽  
Biogeochemical Parameters

Abstract. A dynamic model has been developed to represent biogeochemical variables and processes observed during a bloom of Emiliania huxleyi coccolithophore. This bloom was induced in a mesocosm experiment during which the ecosystem development was followed over a period of 23-days through changes in various biogeochemical parameters such as inorganic nutrients (nitrate, ammonium and phosphate), total alkalinity (TA), dissolved inorganic carbon (DIC), partial pressure of CO2 (pCO2), dissolved oxygen (O2), photosynthetic pigments, particulate organic carbon (POC), dissolved organic carbon (DOC), Transparent Exopolymer Particles (TEP), primary production, and calcification. This dynamic model is based on unbalanced algal growth and balanced bacterial growth. In order to adequately reproduce the observations, the model includes an explicit description of phosphorus cycling, calcification, TEP production and an enhanced mortality due to viral lysis. The model represented carbon, nitrogen and phosphorus fluxes observed in the mesocosms. Modelled profiles of algal biomass and final concentrations of DIC and nutrients are in agreement with the experimental observations.

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