Oceanographic Information Research Articles

TRANSFORMATIONS OF NUTRIENTS IN THE NORTHEASTERN WATERS OF THE SAKHALIN SHELF: AN ANALYSIS OF MATHEMATICAL MODELING RESULTS

Transformations of nutrients in marine environments of the Northeastern part of Sakhalin Shelf were studied in Regions 1–4. Three electronic devices were used for the analysis of the oceanographic information: 1. The GIS «Sakhalin Shelf» (to obtain data on the state of thermohaline parameters of sea waters).2. The oceanic dynamic model of the Bergen University (to estimate the rates of water mass transport across boundaries of regions). 3. The hydroecological CNPSi-model (to calculate the chemical and biological characteristics and estimate qualitatively the features of the marine environment biohydrochemistry in various regions of Northeastern part of Sakhalin Shelf. In this study the seasonal dynamics of the concentrations of organic and mineral substances of biogenic elements (N and P), and organism biomasses (heterotrophic bacteria, three groups of phytoplankton, and two groups of zooplankton are presented, which were reproduced on the basis of the long-term monthly values of the marine environment parameters (temperature, light intensity, transparency of water environment, biogenic load, water exchange parameters). Indicated organisms are involved in the substance transformations and providing their turnover in the water environment. An analysis of the changes in the nutrient concentrations allowed us to characterize the conditions during a year for the explanations of biomass organism development and change in values of their activity parameters (on the base of specific biomass growth rates and bioproductions).

Atmospheric Study of Unusual Cloud & Rainfall Condition over Indonesia Area During the End of 2017-Beginning 2018

Unusual rainfall occurrence at the end of the year 2017 up to beginning 2018 over some places in Indonesia has occurred to reduce the flooding areas that they had developed since November-beginning December 2017.The unusual condition in term of the decreasing of the total daily rainfall over some places in Indonesia area for the period the end of 2017-the beginning 2018 as the period of maximum monthly rainfall of the peak wet season. It would be interesting to be studied using atmospheric and oceanographical data. The data would be collected from several sources of operational meteorological and oceanographical information from Indonesia (BMKG.) and Australia (BoM.).

Atmospheric Study of Unusual Cloud & Rainfall Condition Over Indonesia Area During the End Of 2017 - Beginning 2018

Unusual rainfall occurrence at the end of the year 2017 up to beginning 2018 over some places in Indonesia has occurred to reduce the flooding areas that they had developed since November-beginning December 2017.The unusual condition in term of the decreasing of the total daily rainfall over some places in Indonesia area for the period the end of 2017-the beginning 2018 as the period of maximum monthly rainfall of the peak wet season. It would be interesting to be studied using atmospheric and oceanographical data. The data would be collected from several sources of operational meteorological and oceanographical information from Indonesia (BMKG.) and Australia (BoM.).

Outcomes of the International Oceanographic Data and Information Exchange Ocean Biogeographic Information System OBIS-Event-Data Workshop on Animal Tagging and Tracking

The Ocean Biogeographic Information System (OBIS) began in 2000 as the repository for data from the Census of Marine Life. Since that time, OBIS has expanded its goals beyond simply hosting data to supporting more aspects of marine conservation (Pooter et al. 2017). In order to accomplish those goals, the OBIS secretariat in partnership with its European node (EurOBIS) hosted at the Flanders Marine Institute (VLIZ, Belgium), and the Intergovernmental Oceanographic Commission (IOC) Committee on International Oceanographic Data and Information Exchange (IODE, 23rd session, March 2015, Brugge) established a 2-year pilot project to address a particularly problematic issue that environmental data collected as part of marine biological research were being disassociated from the biological data. OBIS-Event-Data is the solution that was developed from that pilot project, which devised a method for keeping environmental data together with the biological data (Pooter et al. 2017). OBIS is seeking early adopters of the new data standard OBIS-Event-Data from among the marine biodiversity monitoring communities, to further validate the data standard, and develop data products and scientific applications to support the enhancement of Biological and Ecosystem Essential Ocean Variables (EOVs) in the framework of the Global Ocean Observing System (GOOS) and the Marine Biodiversity Observation Network of the Group on Earth Observations (GEO BON MBON). After the successful 2-year IODE pilot project OBIS-ENV-DATA, the IOC established a new 2-year IODE pilot project OBIS-Event-Data for Scientific Applications (2017-2019). The OBIS-Event-Data data standard, building on Darwin Core, provides a technical solution for combined biological and environmental data, and incorporates details about sampling methods and effort, including event hierarchy. It also implements standardization of parameters involved in biological, environmental, and sampling details using an international standard controlled vocabulary (British Oceanographic Data Centre Natural Environment Research Council). A workshop organized by IODE/OBIS in April brought together major animal tagging and tracking networks such as the Ocean Tracking Network (OTN), the Animal Telemetry Network (ATN), the Integrated Marine Observing System (IMOS), the European Tracking Network (ETN) and the Acoustic Tracking Array Platform (ATAP) to test the OBIS-Event-Data standard through the development of some data products and science applications. Additionally, this workshop contributes to the further maturation of the GOOS EOV on fish as well as the EOV on birds, mammals and turtles. We will present the outcomes as well as any lessons learned from this workshop on problems, solutions, and applications of using Darwin Core/OBIS-Event-Data for bio-logging data.

Sr and Mg isotope geochemistry of the basal Ediacaran cap limestone sequence of Mongolia: Implications for carbonate diagenesis, mixing of glacial meltwaters, and seawater chemistry in the aftermath of Snowball Earth

The seawater chemistry and oceanographic information associated with Snowball Earth are commonly inferred from the geochemistry of cap carbonates deposited on continental margins during and after deglaciation. However, interpretation of such records can be complicated by carbonate diagenesis and contamination from siliciclastic components. In an attempt to disentangle these effects, we studied the geochemistry of the post-Marinoan cap carbonate sequence from Mongolia using a step-leaching procedure, which revealed that most samples are heterogeneous with respect to multiple geochemical signatures, including trace element concentrations, Sr, Mg, C and O isotopic signatures, raising questions to previous studies applying carbonate bulk-rock geochemistry for paleoenvironment reconstructions. Such sample heterogeneity can be explained by contamination from non-carbonate phases and carbonate alteration. After stepped leaching, the least-altered/contaminated geochemical signatures for each sample were identified and the influences of carbonate diagenesis were evaluated. Our data indicate that mixing of glacial meltwater persisted to the maximum flooding surface within the cap carbonate sequence, below which carbonates record significant Mg and Sr isotope fluxuations that are most readily interpreted in the context of the mixing of water masses having distinct isotopic compositions. Only limestones deposited above the maximum flooding surface formed in a well-mixed ocean and exhibit Mg and Sr isotope values that record the integrated effects of Snowball Earth on ocean chemistry. Our study cautions against interpreting the geochemistry of cap carbonates in terms of whole ocean geochemical cycles.

Web-based Geovisualization System of Oceanographic Information using Dynamic particles and HTML5

Kim, J., 2018. Web-based Geovisualization System of Oceanographic Information Using Dynamic Particles and HTML5. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1491–1495. Coconut Creek (Florida), ISSN 0749-0208.A web-based geovisualization system of oceanographic information using dynamic particles and HTML5 has been established to address the limitations of the existing Web-GIS based oceanographic information system. The limitations include systematic scalability, slow service speed, a non-standard internet web environment, poor user accessibility and interactivity, and spatial and temporal variability visualization. Importantly, spatial observation data through remote sensing and 3D numerical modeling data are oceanographic data having spatial and temporal variability. Such data are heterogeneous, large capacity, and multidimensional and are based on geographic information. In order to understand intuitively and analyze effectively, dynamic particles were applied to visualize the spatial and temporal variability. This paper introduces the oceanographic information geovisualization system, in which the information inquiry and analysis functions are implemented using open libraries such as HTML5, WebGL, Canvas, D3, and Leaflet map, which are next generation Web platform standards for multimedia service and map with location service.

Fine-scale environmental effects on Cape hake survey catch rates in the northern Benguela, using data from a trawl-mounted instrument package

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 584:185-198 (2017) - DOI: https://doi.org/10.3354/meps12350 Fine-scale environmental effects on Cape hake survey catch rates in the northern Benguela, using data from a trawl-mounted instrument package Paulus Kainge1,2,*, Kai Wieland2 1National Marine Information and Research Centre (NatMIRC), Ministry of Fisheries and Marine Resources, Swakopmund, Namibia 2DTU Aqua - National Institute of Aquatic Resources, Technical University of Denmark, 9850 Hirtshals, Denmark *Corresponding author: paulus.kainge@mfmr.gov.na ABSTRACT: We investigated fine-scale effects of environmental variables associated with habitat distribution for 4 size groups of Cape hakes, Merluccius capensis and M. paradoxus, using generalized additive models (GAMs) with a negative binominal error distribution. This study took place during the Namibian hake trawl survey of 2016, and was made possible for the first time in Namibia by collecting oceanographic information with a trawl-mounted instrument package concurrently with the catch data. Depth, geographical position, bottom oxygen and bottom temperature had the most pronounced effect on the catch rates of both hake species, whereas solar zenith angle representing diel effects and surface layer chlorophyll appeared to be less important. The explained deviance for the best models ranged from 71.4% for M. capensis to 92.7% for M. paradoxus between 43 and 57 cm in length. Differences in catch rates between species and size groups were most pronounced for bottom depth and bottom oxygen. The results show the potential value of trawl-mounted instrumental packages for the collection of reliable environmental data important in the study of environmental influence on abundance, catch rates and distribution, and in turn in the assessment and management of a resource. KEY WORDS: Survey catchability · Bottom trawl catch rates · Benguela current system · Green water effect · Negative binomial GAM · Full text in pdf format Supplementary material PreviousNextCite this article as: Kainge P, Wieland K (2017) Fine-scale environmental effects on Cape hake survey catch rates in the northern Benguela, using data from a trawl-mounted instrument package. Mar Ecol Prog Ser 584:185-198. https://doi.org/10.3354/meps12350 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 584. Online publication date: December 07, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.

Oceanographic Big Data Text Categorization Algorithm Based on Improved Mutual Information

Research on automatic text categorization of the oceanographic big data, has always been the core work of establishing a oceanographic information database based on oceanographic big data information platform. However, in face of extreme complex Internet data and the professional needs of the oceanographic field, the categorization accuracy of the traditional tf-idf algorithm is difficult to meet the demands. Based on traditional tf-idf algorithm and mutual information algorithm, I propose improved tf-idf-miow algorithm in order to meet the demands of text categorization of the oceanographic big data. Optimize the mutual information algorithm, calculate the correlation coefficient between the characteristic word and the oceanographic field. In this way, I set the weight of oceanographic field: miow by this correlation coefficient, and bring miow into traditional tf-idf algorithm. The results of automatic text categorization experiments show that the recall rate of tf-idf-miow in oceanographic field is 10.33% higher than of traditional tf-idf algorithm, and the f1-score is improved by 6.92%.

Detection of potential fishing zone for Pacific saury (Cololabis saira) using generalized additive model and remotely sensed data

To evaluate the effects of oceanographic conditions on the formation of the potential fishing zones for Pacific saury in western North Pacific, fishing locations of Pacific saury from Defense Meteorological Satellite Program/Operating Linescan System (DMSP/OLS) and satellite-based oceanographic information were used to construct species habitat models. A 2-level slicing method was used to identify the bright regions as actual fishing areas from OLS images, collected during the peak fishing season of Pacific saury in the North Pacific. Statistical metrics, including the significance of model terms, and reduction in the Akaike’s Information Criterion (AIC) were used as the bases for model selection. The selected model was then used to visualize the basin scale distributions of the Pacific saury habitat. The predicted potential fishing zones exhibited spatial correspondence with the fishing locations. The results from generalized additive model revealed that the Pacific saury habitat selection was significantly influenced by the SST ranges from 13-18°C, SSC ranges from 0.5-1.8 mg.m-3, SSHA ranges from 5-17 cm and EKE ranges from 700-1200 cm2s-2. Moreover, among the set of oceanographic factors examined, SST explained the smallest AIC and is thus, considered to be the most significant variable in the geographic distribution of Pacific saury.

Annually resolved North Atlantic marine climate over the last millennium.

Owing to the lack of absolutely dated oceanographic information before the modern instrumental period, there is currently significant debate as to the role played by North Atlantic Ocean dynamics in previous climate transitions (for example, Medieval Climate Anomaly-Little Ice Age, MCA-LIA). Here we present analyses of a millennial-length, annually resolved and absolutely dated marine δ18O archive. We interpret our record of oxygen isotope ratios from the shells of the long-lived marine bivalve Arctica islandica (δ18O-shell), from the North Icelandic shelf, in relation to seawater density variability and demonstrate that solar and volcanic forcing coupled with ocean circulation dynamics are key drivers of climate variability over the last millennium. During the pre-industrial period (AD 1000–1800) variability in the sub-polar North Atlantic leads changes in Northern Hemisphere surface air temperatures at multi-decadal timescales, indicating that North Atlantic Ocean dynamics played an active role in modulating the response of the atmosphere to solar and volcanic forcing.

SCUBA divers as oceanographic samplers: The potential of dive computers to augment aquatic temperature monitoring

Monitoring temperature of aquatic waters is of great importance, with modelled, satellite and in-situ data providing invaluable insights into long-term environmental change. However, there is often a lack of depth-resolved temperature measurements. Recreational dive computers routinely record temperature and depth, so could provide an alternate and highly novel source of oceanographic information to fill this data gap. In this study, a citizen science approach was used to obtain over 7,000 scuba diver temperature profiles. The accuracy, offset and lag of temperature records was assessed by comparing dive computers with scientific conductivity-temperature-depth instruments and existing surface temperature data. Our results show that, with processing, dive computers can provide a useful and novel tool with which to augment existing monitoring systems all over the globe, but especially in under-sampled or highly changeable coastal environments.

Modeling and Optimization Algorithms in Ship Weather Routing

Efficient and sustainable sea transport is a key aspect to ensure cost competitive ship operation. The constant need to increase economic feasibility, energy efficiency and safety while complying with emission regulations motivates further developments and improvements in voyage optimization and weather routing systems. These systems optimize a voyage based on meteorological and oceanographic information taking into account ship characteristics and routing information. The quality of the provided route not only depends on the quality of this data, but also on the modeling of the optimization problem and the algorithm chosen to solve it. Due to the wide range of mathematical approaches and consequently challenges in decision making, this paper aims to give a comprehensive and comparative overview of the existing state-of-the-art methods by a thorough literature review and elaboration of different modeling approaches, optimization algorithms, and their application in weather routing systems. The research shows that approaches range from modeling the weather routing problem as a constrained graph problem, a constrained nonlinear optimization problem or as combination of both. Based on the formulation of the ship weather routing optimization problem different methods are used to solve it ranging from Dijkstra's algorithm, dynamic programing and optimal control methods to isochrone methods or iterative approaches for solving nonlinear optimization problems. However, it can be concluded that the determination whether an approach is suitable, produces sufficient results and may be recommended, strongly depends on the specific requirements concerning optimization objectives, control variables and constraints as well as the implementation.

Mudanças de curto prazo no balanço sedimentar da Praia do Icaraí (Caucaia, Ceará) durante uma ressaca do mar

Este artigo apresenta resultados de um experimento de campo realizado para avaliar a resposta morfológica de uma praia arenosa durante um evento de ressaca do mar. O estudo foi realizado na Praia do Icaraí, localizada no litoral da Região Metropolitana de Fortaleza. O experimento de campo foi baseado no acompanhamento contínuo de cinco seções de controle a partir de informações topográficas e oceanográficas. Foram realizadas 7 campanhas de campo (28/01/14 a 09/02/14). As respostas morfológicas dos trechos observados foram diferentes em termos de erosão e deposição. A seção limitada por dunas antropizadas (S1) apresentou erosão da berma e da praia submersa. Os trechos costeiros limitados por uma estrutura de proteção costeira (S2 a S4) apresentaram recuo da parte superior do perfil. No trecho de dunas frontais (S5), houve uma erosão generalizada da duna e da berma. De forma geral, a Praia do Icaraí é vulnerável a eventos de ressaca do mar.

Preliminary Results of Satellite SAR Monitoring of Oil Spills in the Barents Sea

Analyzed are the preliminary results of satellite radar monitoring of oil spills in the Barents Sea. For the first time on a regular basis, it took place in 2015 – 2016 using synthetic aperture radar (SAR) images of the European Space Agency’ Sentinel-1A satellite. To effectively analyze radar data used geoinformation (GIS) approach, in which on-line GIS or geoportal based on GeoMixer technology, a large volume of oceanographic, physical-geographical and industrial information about the water basin has been collected, including on oil and gas infrastructure and the vulnerability of the coasts, have been used. With the use of new approaches and methods of analysis and data automatic ship identification systems it is shown that main source of oil spills with area from 0.5 to 90 km 2 is a cargo shipping and fishing. Summary maps of detected and mapped oil spills in 2015 – 2016 are presented and discussed.

Contourite drifts and canyon-channel systems on the Northern Antarctic Peninsula Pacific margin

Contourite drifts, also known as sediment drifts, result from near-bottom currents usually flowing in deep water in response to thermohaline and wind-driven circulation (Faugeres & Stow 2008). They are present throughout the world’s oceans and can be found anywhere from the abyssal floor to outer shelf settings. Contourite drifts typically display elongate mounded shapes with sizes ranging from tens to hundreds of square kilometres. In high latitudes the development of contourite drifts is favoured by the formation of cold dense waters and the delivery of large volumes of sediment by fast-flowing ice streams on the outer shelf during glacial periods (McGinnis & Hayes 1995). Several large sedimentary mounds, interpreted as sediment drifts, are located along the Pacific margin of the Antarctic Peninsula upper continental rise (Fig. 1b). These mounds have been interpreted as contourite drifts produced by SW-flowing bottom currents redistributing the fine-grained component of channelized turbidity currents (Rebesco et al. 1996; Amblas et al. 2006). The sediment drifts contain climatic and oceanographic information valuable for the reconstruction of Neogene Antarctic …

The generalized data management and collection protocol for Conductivity-Temperature-Depth Satellite Relay Data Loggers

The software routines for data sampling and processing that are implemented on-board telemetry devices (tags) called Conductivity-Temperature-Depth Satellite Relay Data Loggers (CTD-SRDLs) enable the simultaneous collection of biological and in-situ environmental data by animal-platforms over periods of weeks to months, despite severe energy and bandwidth limitations imposed by their relatively small size. This extended operational lifetime is made possible by the use of software protocols on-board the tags that manage sensors, data collection, storage, compression and transmission to ensure that the most useful data are sent at appropriate resolution while minimizing redundancy. While tag software is tailored to the particular species under study and the questions being addressed with a given field deployment, the philosophy behind Sea Mammal Research Unit Instrumentation Group (SMRU-IG) software protocols is to adopt a general set of principles to achieve the best results within the energy and bandwidth constraints. Here, we discuss these and review the general protocol that is used to simultaneously collect information on geographical movements, diving behaviour and in-situ oceanographic information from marine mammals.

A review of trend models applied to sea level data with reference to the “acceleration‐deceleration debate”

AbstractGlobal sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. This has motivated a number of authors to search for already existing accelerations in observations, which would be, if present, vital for coastal protection planning purposes. No scientific consensus has been reached yet as to how a possible acceleration could be separated from intrinsic climate variability in sea level records. This has led to an intensive debate on its existence and, if absent, also on the general validity of current future projections. Here we shed light on the controversial discussion from a methodological point of view. To do so, we provide a comprehensive review of trend methods used in the community so far. This resulted in an overview of 30 methods, each having its individual mathematical formulation, flexibilities, and characteristics. We illustrate that varying trend approaches may lead to contradictory acceleration‐deceleration inferences. As for statistics‐oriented trend methods, we argue that checks on model assumptions and model selection techniques yield a way out. However, since these selection methods all have implicit assumptions, we show that good modeling practices are of importance too. We conclude at this point that (i) several differently characterized methods should be applied and discussed simultaneously, (ii) uncertainties should be taken into account to prevent biased or wrong conclusions, and (iii) removing internally generated climate variability by incorporating atmospheric or oceanographic information helps to uncover externally forced climate change signals.

Modeling the Northern Coastline of Yucatan, Mexico, with GENESIS

The sandy coast of the State of Yucatan is subject to natural and anthropogenic disturbances. Coastal erosion is a clear example of these disturbances. Many actions have been proposed and implemented to combat this problem; however, they have been counterproductive. In the present work the evolution of the northern coastline of Yucatan, Mexico was studied. The GENESIS model was applied to assess the effect of groins, breakwaters parallel to the coast and sand nourishment. The model was calibrated with available oceanographic information; a thorough treatment of this information made the calibration consistent. It was found that: a) the obliquity of the incidence wave is the main cause of longitudinal sediment transport; b) the sediment transport produced as a result of the wave height gradient along the coast is negligible; and c) the incident waves on the coast present very low energy and are governed mainly by local wind action. The flexibility provided by the calibration coefficients in GENESIS allowed it to be used on the beaches of Yucatan; the values obtained during this research reproduced in an acceptable manner both the morphological changes observed and the volumetric variability of sediments. For these values and the calibration conditions, the model can be applied to analyze the evolution of the beaches in the Yucatan. Furthermore, it reinforces the hypothesis that the groins have accelerated erosion, breakwaters off the coast are a viable alternative to coastal erosion in the study area, and the placement of artificial sand is just a temporary solution.

Estimating trans-seasonal variability in water column biomass for a highly migratory, deep diving predator.

The deployment of animal-borne electronic tags is revolutionizing our understanding of how pelagic species respond to their environment by providing in situ oceanographic information such as temperature, salinity, and light measurements. These tags, deployed on pelagic animals, provide data that can be used to study the ecological context of their foraging behaviour and surrounding environment. Satellite-derived measures of ocean colour reveal temporal and spatial variability of surface chlorophyll-a (a useful proxy for phytoplankton distribution). However, this information can be patchy in space and time resulting in poor correspondence with marine animal behaviour. Alternatively, light data collected by animal-borne tag sensors can be used to estimate chlorophyll-a distribution. Here, we use light level and depth data to generate a phytoplankton index that matches daily seal movements. Time-depth-light recorders (TDLRs) were deployed on 89 southern elephant seals (Mirounga leonina) over a period of 6 years (1999–2005). TDLR data were used to calculate integrated light attenuation of the top 250 m of the water column (LA250), which provided an index of phytoplankton density at the daily scale that was concurrent with the movement and behaviour of seals throughout their entire foraging trip. These index values were consistent with typical seasonal chl-a patterns as measured from 8-daySea-viewing Wide Field-of-view Sensor (SeaWiFs) images. The availability of data recorded by the TDLRs was far greater than concurrent remotely sensed chl-a at higher latitudes and during winter months. Improving the spatial and temporal availability of phytoplankton information concurrent with animal behaviour has ecological implications for understanding the movement of deep diving predators in relation to lower trophic levels in the Southern Ocean. Light attenuation profiles recorded by animal-borne electronic tags can be used more broadly and routinely to estimate lower trophic distribution at sea in relation to deep diving predator foraging behaviour.

A comparison of measured and forecast acoustic propagation in a virtual denied area characterized by a heterogeneous data collection asset-network

The fidelity of sonar performance predictions depends on the model used and the quantity and quality of the environmental information that is available. To investigate the impact of the oceanographic information collected by a heterogeneous and near-real time adaptive network of robots in a simulated access denied area, a field experiment (REP13-MED) was conducted by CMRE during August 2013 in an area (70 × 81 km) located off-shore La Spezia (Italy), in the Ligurian Sea. The sonar performance assessment makes use of acoustic data recorded by a vertical line array at source—receiver ranges from 0.5 to 30 km. Continuous wave pulses at multiple frequencies (300–600 Hz) were transmitted at two source depths, 25 and 60 meters, at each range. At least 60 pings were collected for each source depth to build up the statistics of the acoustic received level and quantify the measurement uncertainty. A comparison of the acoustic transmission loss measured and predicted using an ocean prediction model (ROMS) assimilating the observed oceanographic data is presented, and the performance of the observational network is evaluated. [Work funded by NATO–Allied Command Transformation]