Ocean Observing System Research Articles

Initial evaluations of a Gulf of Mexico/Caribbean ocean forecast system in the context of the Deepwater Horizon disaster

In response to the Deepwater Horizon (DwH) oil spill event in 2010, the Naval Oceanographic Office deployed a nowcast-forecast system covering the Gulf of Mexico and adjacent Caribbean Sea that was designated Americas Seas, or AMSEAS, which is documented in this manuscript. The DwH disaster provided a challenge to the application of available ocean-forecast capabilities, and also generated a historically large observational dataset. AMSEAS was evaluated by four complementary efforts, each with somewhat different aims and approaches: a university research consortium within an Integrated Ocean Observing System (IOOS) testbed; a petroleum industry consortium, the Gulf of Mexico 3-D Operational Ocean Forecast System Pilot Prediction Project (GOMEX-PPP); a British Petroleum (BP) funded project at the Northern Gulf Institute in response to the oil spill; and the Navy itself. Validation metrics are presented in these different projects for water temperature and salinity profiles, sea surface wind, sea surface temperature, sea surface height, and volume transport, for different forecast time scales. The validation found certain geographic and time biases/errors, and small but systematic improvements relative to earlier regional and global modeling efforts. On the basis of these positive AMSEAS validation studies, an oil spill transport simulation was conducted using archived AMSEAS nowcasts to examine transport into the estuaries east of the Mississippi River. This effort captured the influences of Hurricane Alex and a non-tropical cyclone off the Louisiana coast, both of which pushed oil into the western Mississippi Sound, illustrating the importance of the atmospheric influence on oil spills such as DwH.

SEM+: tool for discovering concept mapping in Earth science related domain

The amount of Earth Science related domain concepts and vocabularies encoded in popular Semantic Web languages such as OWL and SKOS grows rapidly as more and more domain scientists realize the power of Semantic Web Technologies. The interlinking between these concepts will enable the possibility of performing data integration and identity recognition, which is crucial in developing applications that use data from multiple sources. In this paper, we discuss a new tool for performing concept mapping called SEM+. In SEM+, we designed the Information Entropy based Weighted Similarity Model to compute semantic similarity between entity data and suggest possible linking. We also adopted a blocking approach to group possible matching entities into one block and therefore reduce the computation space. We performed evaluations on SEM+ using the Integrated Ocean Observatory System ontology and the Marine Metadata Interoperability ontology and discussed the results and new findings.

Cooperative Multi Agent System for Ocean Observation System based on Consensus Algorithm

In this paper, we present a cooperative decision making problem of multi agent system for ocean observation system. We consider a team of agents consisting of three blimps and buoys. The aim is to obtain cohesion in heading for the multi blimp to assist aerial mapping and act as the communication hub for a series of ODAS buoy. The ocean observation framework is design suited to the coral reef environment condition. The cooperative solution proposed is based on animal inspired consensus for small flock. The consensus algorithm is developed to solve reach agreement as a whole to acquire the best heading. The results show fast converges of consensus and the effectiveness were demonstrated through numerical simulations.

Institutional coordination of global ocean observations

A sustainable global ocean observation system requires timely implementation of the framework for ocean observing. The recent Qingdao Global Ocean Summit highlighted the need for a more coherent institutional response to maintain an integrated ocean-observing system.

Advances in earthquake and tsunami sciences and disaster risk reduction since the 2004 Indian ocean tsunami

The December 2004 Indian Ocean tsunami was the worst tsunami disaster in the world’s history with more than 200,000 casualties. This disaster was attributed to giant size (magnitude M ~ 9, source length >1000 km) of the earthquake, lacks of expectation of such an earthquake, tsunami warning system, knowledge and preparedness for tsunamis in the Indian Ocean countries. In the last ten years, seismology and tsunami sciences as well as tsunami disaster risk reduction have significantly developed. Progress in seismology includes implementation of earthquake early warning, real-time estimation of earthquake source parameters and tsunami potential, paleoseismological studies on past earthquakes and tsunamis, studies of probable maximum size, recurrence variability, and long-term forecast of large earthquakes in subduction zones. Progress in tsunami science includes accurate modeling of tsunami source such as contribution of horizontal components or “tsunami earthquakes”, development of new types of offshore and deep ocean tsunami observation systems such as GPS buoys or bottom pressure gauges, deployments of DART gauges in the Pacific and other oceans, improvements in tsunami propagation modeling, and real-time inversion or data assimilation for the tsunami warning. These developments have been utilized for tsunami disaster reduction in the forms of tsunami early warning systems, tsunami hazard maps, and probabilistic tsunami hazard assessments. Some of the above scientific developments helped to reveal the source characteristics of the 2011 Tohoku earthquake, which caused devastating tsunami damage in Japan and Fukushima Dai-ichi Nuclear Power Station accident. Toward tsunami disaster risk reduction, interdisciplinary and trans-disciplinary approaches are needed for scientists with other stakeholders.

OSSE impact analysis of airborne ocean surveys for improving upper-ocean dynamical and thermodynamical forecasts in the Gulf of Mexico

A prototype, rigorously validated ocean Observing System Simulation Experiment (OSSE) system is used to evaluate the impact of different sampling strategies for rapid-response airborne ocean profile surveys in the eastern interior Gulf of Mexico. Impacts are assessed with respect to improving ocean analyses, and forecasts initialized from those analyses, for two applications: improving oil spill forecasts and improving the ocean model response to tropical cyclone (TC) forcing. Rapid model error growth in this region requires that repeat surveys be conducted frequently in time, with separation of less than 4 days required to approach maximum error reduction in model analyses. Substantial additional error reduction in model dynamical fields is achieved by deploying deep (1000m) AXCTDs instead of shallow (400m) AXBTs. Shallow AXBTs constrain the ocean thermal field over the upper 400m nearly as well as deep AXCTDs. However, in addition to constraining ocean fields over a greater depth range, AXCTDs also measure salinity profiles and more accurately constrain upper-ocean density than AXBTs, leading to a more accurate representation of upper ocean pressure and velocity fields. Sampling AXCTD profiles over a one-half degree array compared to one degree leads to substantial additional error reduction by constraining variability with horizontal scales too small to be corrected by satellite altimetry assimilation. A 2-day lag in availability of airborne profiles does not increase errors in dynamical ocean fields, but it does increase errors in upper-ocean thermal field including Tropical Cyclone Heat Potential (TCHP), demonstrating that these profiles must be rapidly made available for assimilation to improve TC forecasts. The additional error reduction in ocean analyses achieved by assimilation of airborne surveys translates into significantly improved forecasts persisting over time intervals ranging between 1 and 2 weeks for most model variables but several weeks for TCHP. In particular, upper-ocean temperature forecasts can be significantly improved for an extended interval of time by conducting airborne profile surveys.

Linking marine mammal and ocean health in the ‘New Normal’ arctic

The ‘New Normal’ Arctic ecosystem and the reliance of indigenous people on marine mammals for subsistence makes urgent the need for a comprehensive marine mammal health monitoring program linked to regional ocean observing systems. An Arctic-focused Marine Mammal Health Map (MMHM) framework could be initiated via expansion and coordination between regional Ocean Observing Systems and Community-based Monitoring Programs. In the US, this approach would build upon three activities currently supported by the Alaska Ocean Observing System (AOOS): ocean data access, community based monitoring and spatial tools for data visualization. The new MMHM framework would support a more holistic understanding of climate change impacts to ocean ecosystems, aid in the prioritization of management efforts to mitigate impacts to marine mammals and complement marine ecosystem monitoring programs fostered by the Arctic Council and UNESCO. Ultimately, we advocate for the inclusion of MMHM products as ‘essential ocean variables’ in the Global Ocean Observing System (GOOS).

Standards-Based Plug & Work for Instruments in Ocean Observing Systems

Ocean observing systems may include a wide variety of sensor and instrument types, each with its own capabilities, communication protocols, and data formats. Connecting disparate devices into a network typically requires specialized software drivers that translate command and data between the protocols of the individual instruments, and that of the platform on which they are installed. In addition, such platforms typically require extensive manual configuration to match the driver software and other operational details of each network port to a specific connected instrument. In this paper, we describe an approach to “plug & work” interoperability, using standardized protocols to greatly reduce the amount of instrument-specific software and manual configuration required for connecting instruments to an observatory system. Our approach has two main components. First, we use the sensor interface descriptor (SID) model, based on the Open Geospatial Consortium's (OGC) SensorML standard, to describe each instrument's protocol and data format, and to provide a generic driver/parser. Second, a new OGC standard known as the programmable underwater connector with knowledge (PUCK) protocol enables storage and retrieval of the SID file from the instrument itself. We demonstrate and evaluate our approach by applying it to three commonly used marine instruments in the OBSEA (Barcelona, Spain) observatory test bed.

Real-Time Observations of the February 2010 Chile and March 2011 Japan Tsunamis Recorded in Honolulu by the Pacific Islands Ocean Observing System

Real-Time Observations of the February 2010 Chile and March 2011 Japan Tsunamis Recorded in Honolulu by the Pacific Islands Ocean Observing System

EMSO: A Distributed Infrastructure for Addressing Geohazards and Global Ocean Change

The European Multidisciplinary Seafloor and water-column Observatory (EMSO; http://www.emso-eu.org) is addressing the next challenge in Earth-ocean science: how to coordinate data acquisition, analysis, archiving, access, and response to geohazards across provincial, national, regional, and international boundaries. Such coordination is needed to optimize the use of current and planned ocean observatory systems to (1) address national and regional public safety concerns about geohazards (e.g., earthquakes, submarine landslides, tsunamis) and (2) permit broadening of their scope toward monitoring environmental change on global ocean scales.

Enhancing the Global Ocean Observing System to meet evidence based needs for the ecosystem‐based management of coastal ecosystem services

AbstractEcosystem‐based approaches (EBAs) to managing anthropogenic pressures on ecosystems, adapting to changes in ecosystem states (indicators of ecosystem health), and mitigating the impacts of state changes on ecosystem services are needed for sustainable development. EBAs are informed by integrated ecosystem assessments (IEAs) that must be compiled and updated frequently for EBAs to be effective. Frequently updated IEAs depend on the sustained provision of data and information on pressures, state changes, and impacts of state changes on services. Nowhere is this truer than in the coastal zone, where people and ecosystem services are concentrated and where anthropogenic pressures converge. This study identifies the essential indicator variables required for the sustained provision of frequently updated IEAs, and offers an approach to establishing a global network of coastal observations within the framework of the Global Ocean Observing System. The need for and challenges of capacity‐building are highlighted, and examples are given of current programmes that could contribute to the implementation of a coastal ocean observing system of systems on a global scale. This illustrates the need for new approaches to ocean governance that can achieve coordinated integration of existing programmes and technologies as a first step towards this goal.

Coordinated management of coastal hazard awareness and preparedness in the USVI

Abstract. As far back as history has been written in the islands today known as the US Virgin Islands (USVI), residents have had to endure and survive costly and deadly onslaughts from tropical storms such as the 1867 San Narciso Hurricane, Hurricane Hugo and Hurricane Marilyn. Keenly alerted by recent tragic events in the Indian Ocean in 2004, in Haiti in 2010 and in Japan in 2011, the USVI was reminded that it had suffered its greatest tsunami impact in a well-documented event that had followed the 1867 hurricane by fewer than three weeks. To address their community's continual vulnerability to coastal hazards, USVI emergency managers, scientists and educators, assisted by national and regional disaster management agencies and warning programs, have engaged programs for understanding, anticipating and mitigating these hazards. This paper focuses on how three public-serving institutions, the Virgin Islands Territorial Emergency Management Agency (VITEMA), the University of the Virgin Islands and the Caribbean Ocean Observing System have responded to the community's need for improved preparedness through programs of physical preparation, planning, research, observations, education and outreach. This report reviews some of the approaches and activities employed in the USVI in the hope of sharing their benefits with similarly vulnerable coastal communities.

Advances in a Distributed Approach for Ocean Model Data Interoperability

An infrastructure for earth science data is emerging across the globe based on common data models and web services. As we evolve from custom file formats and web sites to standards-based web services and tools, data is becoming easier to distribute, find and retrieve, leaving more time for science. We describe recent advances that make it easier for ocean model providers to share their data, and for users to search, access, analyze and visualize ocean data using MATLAB® and Python®. These include a technique for modelers to create aggregated, Climate and Forecast (CF) metadata convention datasets from collections of non-standard Network Common Data Form (NetCDF) output files, the capability to remotely access data from CF-1.6-compliant NetCDF files using the Open Geospatial Consortium (OGC) Sensor Observation Service (SOS), a metadata standard for unstructured grid model output (UGRID), and tools that utilize both CF and UGRID standards to allow interoperable data search, browse and access. We use examples from the U.S. Integrated Ocean Observing System (IOOS®) Coastal and Ocean Modeling Testbed, a project in which modelers using both structured and unstructured grid model output needed to share their results, to compare their results with other models, and to compare models with observed data. The same techniques used here for ocean modeling output can be applied to atmospheric and climate model output, remote sensing data, digital terrain and bathymetric data.

Satellite Remote Sensing in Support of an Integrated Ocean Observing System

Earth observing satellites represent some of the most valued components of the international Global Ocean Observing System (GOOS) and of the Global Climate Observing System (GCOS), both part of the Global Earth Observation System of Systems (GEOSS). In the United States, such satellites are a cornerstone of the Integrated Ocean Observing System (IOOS), required to carry out advanced coastal and ocean research, and to implement and sustain sensible resource management policies based on science. Satellite imagery and satellite-derived data are required for mapping vital coastal and marine resources, improving maritime domain awareness, and to better understand the complexities of land, ocean, atmosphere, ice, biological, and social interactions. These data are critical to the strategic planning of in situ observing components and are critical to improving forecasting and numerical modeling. Specifically, there are several stakeholder communities that require periodic, frequent, and sustained synoptic observations. Of particular importance are indicators of ecosystem structure (habitat and species inventories), ecosystem states (health and change) and observations about physical and biogeochemical variables to support the operational and research communities, and industry sectors including mining, fisheries, and transportation. IOOS requires a strategy to coordinate the human capacity, and fund, advance, and maintain the infrastructure that provides improved remote sensing observations and support for the nation and the globe. A partnership between the private, government, and education sectors will enhance remote sensing support and product development for critical coastal and deep-water regions based on infrared, ocean color, and microwave satellite sensors. These partnerships need to include international research, government, and industry sectors in order to facilitate open data access, understanding of calibration and algorithm strategies, and fill gaps in coverage. Such partnerships will define the types of observations required to sustain vibrant coastal economies and to improve the health of our marine and coastal ecosystems. They are required to plan, fund, launch and operate the types of satellite sensors needed in the very near future to maintain continuity of observations.

Extratropical storm inundation testbed: Intermodel comparisons in Scituate, Massachusetts

[1] The Integrated Ocean Observing System Super-regional Coastal Modeling Testbed had one objective to evaluate the capabilities of three unstructured-grid fully current-wave coupled ocean models (ADCIRC/SWAN, FVCOM/SWAVE, SELFE/WWM) to simulate extratropical storm-induced inundation in the US northeast coastal region. Scituate Harbor (MA) was chosen as the extratropical storm testbed site, and model simulations were made for the 24–27 May 2005 and 17–20 April 2007 (“Patriot's Day Storm”) nor'easters. For the same unstructured mesh, meteorological forcing, and initial/boundary conditions, intermodel comparisons were made for tidal elevation, surface waves, sea surface elevation, coastal inundation, currents, and volume transport. All three models showed similar accuracy in tidal simulation and consistency in dynamic responses to storm winds in experiments conducted without and with wave-current interaction. The three models also showed that wave-current interaction could (1) change the current direction from the along-shelf direction to the onshore direction over the northern shelf, enlarging the onshore water transport and (2) intensify an anticyclonic eddy in the harbor entrance and a cyclonic eddy in the harbor interior, which could increase the water transport toward the northern peninsula and the southern end and thus enhance flooding in those areas. The testbed intermodel comparisons suggest that major differences in the performance of the three models were caused primarily by (1) the inclusion of wave-current interaction, due to the different discrete algorithms used to solve the three wave models and compute water-current interaction, (2) the criterions used for the wet-dry point treatment of the flooding/drying process simulation, and (3) bottom friction parameterizations.

Ocean Space and the Anthropocene, new notions in geosciences? – An essay

AbstractTwo notions, Ocean Space and the Anthropocene, are discussed. The first is occasionally used in legal and governance literature, and in the media. The Anthropocene, however, is widely applied in the global change research community and the media. The notion of ocean space stands for a holistic, system science approach combined with 4D thinking from the ocean, and the processes within it, towards the land. Ocean space is in fact a social-ecological concept that deals with sustainability challenges which are the consequence of the complex interactions between humans and the marine environment on all scales. Ocean space is, on a human scale, impressively large. On a planetary scale, however, it is insignificant, although it has been an ancient feature of the Earth for the last four billion years or so. Yet, ocean space is a critical player in the Earth System; it is central to climate regulation, the hydrological and carbon cycles and nutrient flows, it balances levels of atmospheric gases, it is a source of raw materials vital for medical and other uses, and a sink for anthropogenic pollutants. The notion also encompasses issues such as exploration, adventure, science, resources, conservation, sustainability, etc., and should be an innovative and attractive outreach instrument for the media. Finally, it marks the fundamental change in ocean exploration in the twenty-first century in which ocean-observing systems, and fleets of robots, are routinely and continuously providing quality controlled data and information on the present and future states of ocean space. Advocates of the notion of the Anthropocene argue that this new epoch in geological time, commenced with the British industrial revolution. To date, the Anthropocene has already been subdivided into three stages. The first of these coincides with the beginning of the British industrial revolution around 1800. This transition quickly transformed a society which used natural energy sources into one that uses fossil fuels. The present high-energy society of more than seven billion people mostly with highly improved living standards and birth rates, and a global economy, is the consequence. The downside of this development comprises intensive resource and land use as well as large-scale pollution of the (marine) environment. The first stage of the Anthropocene ended abruptly after the Second World War when a new technology push occurred, leading to the second stage: ‘the Great Acceleration’ (1945-2015) followed by the third: ‘Stewards of the Earth’. Here it is concluded that the notion of the Anthropocene reflects a hierarchical or individualistic perspective, often leading to a ‘business as usual’ management style, and ‘humanises’ the geological time scale. The use of this notion is not supported. However, it is already very popular in the media. This again might lead to overestimating the role of humans in nature, and might facilitate an even more destructive attitude towards it, through the application of geo-engineering. The latter could be opening another Pandora's box. Instead we should move to a more sustainable future in which human activities are better fine tuned to the environment that we are part of. In this respect, transition management is an interesting new paradigm.

Reliability of rapid, semi‐automated assessment of plankton abundance, biomass, and growth rate estimates: Coulter Counter versus light microscope measurements

Here we determined (1) how accurately the semi‐automated Coulter Counter (CC) measured the abundance, volume, and growth rates of mono‐specific plankton cultures compared to light microscopy and (2) whether CC‐derived particle size‐abundance spectra of whole water samples provided a near‐real time assessment of plankton community composition. A significant, positive relationship was found between CC particle and microscope cell abundance and volume estimates for 16 phylogenetically diverse plankton species. However, abundance estimates of the 2 methods differed significantly from a 1:1 relationship, with CC counts on average 15% greater than microscopy counts. Growth rate estimates showed excellent agreement for both methods for all species and were consistent over time. No significant differences in abundance, growth rate, or size estimates were observed due to light levels (Scrippsiella trochoidea) or strain variation (Heterosigma akashiwo). CC‐based, ship‐board characterization of whole plankton communities, from Georges Bank, captured changes in size‐abundance spectra and thus provided a coarse picture of in‐situ community composition. In the laboratory, the CC appears particularly well‐suited to measuring relative changes in cell abundance, such as for growth and grazing rate measurements of mono‐specific laboratory cultures, or when predator and prey species are well separated by size differences. Although microscopy remains essential for plankton analyses, these results suggest that the CC can increase sample size, improving accuracy, and precision of studies requiring frequent sampling or high degrees of replication. Deployment of these automated techniques in the field may aid in quantifying spatial and temporal variability in plankton community structure by forthcoming ocean‐observing systems.

Influence of recent depositional and tectonic controls on marine gas hydrates in Trujillo Basin, Peru Margin

Abstract The development of bottom simulating reflectors (BSRs) and the gas hydrate stability zone (GHSZ) in continental margins is related to recent depositional and tectonic processes. This interrelation is important for understanding the potential resource of gas hydrate deposits. The purpose of this study is to understand the influence of such activity on the marine gas hydrate system of the seaward extension of the Trujillo Basin, Peru Margin. Here, we analyze near-seafloor heat flow probe data, high-resolution multichannel seismic (MCS) profiles, swath bathymetry and ocean floor observation system (OFOS) images. Based on our results, we identify three main physiographical subregions in the study area: (1) an area with turbidites, continuous BSRs and low-to-moderate near-seafloor heat flow (7–33 mW/m2), (2) an area with sediment waves of turbidity origin, a mix of continuous and patchy BSRs, and moderate near-seafloor heat flow (26–39 mW/m2), (3) an area with extensional faulting, patchy BSRs and moderate-to-high near-seafloor heat flow (52–110 mW/m2). We conclude that sediment flow processes are the result of recent depositional controls, and faulting is the result of recent tectonic activity. Near-seafloor heat flow around chemoherms is moderate. Estimates of BSR-derived heat flow show differences to near-seafloor heat flow. This difference points to advection of fluids occurring at the seafloor. Alive Calyptogena and tube worms were observed in these venting zones. Based on our analysis, we conclude that: (1) recent depositional processes control the development of continuous BSRs and may restrict heat transfer through the GHSZ in the form of fluid venting at the seafloor, (2) recent tectonic processes control the development of patchy BSRs and allow heat transfer through the GHSZ along faults, which is manifested as fluid venting at the seafloor.

Study on 10 kVDC powered junction box for a cabled ocean observatory system

A cabled ocean observatory system that can provide abundant power and broad bandwidth communication for undersea instruments is developed. A 10 kV direct current (kVDC) with up to 10 kW power, along with 1 Gigabit/sec Ethernet communication, can be transmitted from the shore to the seafloor through an umbilical armored cable. A subsea junction box is fixed at a cable terminal, enabling the extension of up to nine connections. The box consists of three main pressure vessels that perform power conversion, power distribution, and real-time communication functions. A method of stacking modules is used to design the power conversion system in order to reduce the 10 kV voltage to levels that can power the attached instruments. A power distribution system and an Ethernet communication system are introduced to control the power supply and transmit data or commands between the terminals and the shore station, respectively. Specific validations of all sections were qualified in a laboratory environment prior to the sea trial. The ocean observatory system was then deployed at the coast of the East China Sea along with three in situ instruments for a 14-day test. The results show that this high voltage-powered observatory system is effective for subsea long-term and real-time observations.

Enhancing the Ocean Observing System to Meet Restoration Challenges in the Gulf of Mexico

Enhancing the Ocean Observing System to Meet Restoration Challenges in the Gulf of Mexico