24,846 research outputs found

    Advanced space system concepts and their orbital support needs (1980 - 2000). Volume 3: Detailed data. Part 1: Catalog of initiatives, functional options, and future environments and goals

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    The following areas were discussed in relation to a study of the commonality of space vehicle applications to future national needs: (1) index of initiatives (civilian observation, communication, support), brief illustrated description of each initiative, time periods (from 1980 to 2000+) for implementation of these initiatives; (2) data bank of functional system options, presented in the form of data sheets, one for each of the major functions, with the system option for near-term, midterm, and far-term space projects applicable to each subcategory of functions to be fulfilled; (3) table relating initiatives and desired goals (public service and humanistic, materialistic, scientific and intellectual); and (4) data on size, weight and cost estimations

    An acoustic view of ocean mixing

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    Knowledge of the parameter K (turbulent diffusivity/"mixing intensity") is a key to understand transport processes of matter and energy in the ocean. Especially the almost vertical component of K across the ocean stratification (diapycnal diffusivity) is vital for research on biogeochemical cycles or greenhouse gas budgets. Recent boost in precision of water velocity data that can be obtained from vessel-mounted acoustic instruments (vmADCP) allows identifying ocean regions of elevated diapycnal diffusivity during research cruises - in high horizontal resolution and without extra ship time needed. This contribution relates acoustic data from two cruises in the Tropical North East Atlantic Oxygen Minimum Zone to simultaneous field observations of diapycnal diffusivity: pointwise measurements by a microstructure profiler as well as one integrative value from a large scale Tracer Release Experiment

    The Hierarchic treatment of marine ecological information from spatial networks of benthic platforms

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    Measuring biodiversity simultaneously in different locations, at different temporal scales, and over wide spatial scales is of strategic importance for the improvement of our understanding of the functioning of marine ecosystems and for the conservation of their biodiversity. Monitoring networks of cabled observatories, along with other docked autonomous systems (e.g., Remotely Operated Vehicles [ROVs], Autonomous Underwater Vehicles [AUVs], and crawlers), are being conceived and established at a spatial scale capable of tracking energy fluxes across benthic and pelagic compartments, as well as across geographic ecotones. At the same time, optoacoustic imaging is sustaining an unprecedented expansion in marine ecological monitoring, enabling the acquisition of new biological and environmental data at an appropriate spatiotemporal scale. At this stage, one of the main problems for an effective application of these technologies is the processing, storage, and treatment of the acquired complex ecological information. Here, we provide a conceptual overview on the technological developments in the multiparametric generation, storage, and automated hierarchic treatment of biological and environmental information required to capture the spatiotemporal complexity of a marine ecosystem. In doing so, we present a pipeline of ecological data acquisition and processing in different steps and prone to automation. We also give an example of population biomass, community richness and biodiversity data computation (as indicators for ecosystem functionality) with an Internet Operated Vehicle (a mobile crawler). Finally, we discuss the software requirements for that automated data processing at the level of cyber-infrastructures with sensor calibration and control, data banking, and ingestion into large data portals.Peer ReviewedPostprint (published version

    Bayesian Learning and Predictability in a Stochastic Nonlinear Dynamical Model

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    Bayesian inference methods are applied within a Bayesian hierarchical modelling framework to the problems of joint state and parameter estimation, and of state forecasting. We explore and demonstrate the ideas in the context of a simple nonlinear marine biogeochemical model. A novel approach is proposed to the formulation of the stochastic process model, in which ecophysiological properties of plankton communities are represented by autoregressive stochastic processes. This approach captures the effects of changes in plankton communities over time, and it allows the incorporation of literature metadata on individual species into prior distributions for process model parameters. The approach is applied to a case study at Ocean Station Papa, using Particle Markov chain Monte Carlo computational techniques. The results suggest that, by drawing on objective prior information, it is possible to extract useful information about model state and a subset of parameters, and even to make useful long-term forecasts, based on sparse and noisy observations

    Models for an Ecosystem Approach to Fisheries

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    This document is one outcome from a workshop held in Gizo in October 2010 attended by 82 representatives from government, NGO's private sector, and communities. The target audience for the document is primarily organizations planning to work with coastal communities of Solomon Islands to implement Community-Based Resource Management (CBRM). It is however also envisaged that the document will serve as a reference for communities to better understand what to expect from their partners and also for donors, to be informed about agreed approaches amongst Solomon Islands stakeholders. This document does not attempt to summarize all the outcomes of the workshop; rather it focuses on the Solomon Islands Coral Triangle Initiative (CTI) National Plan of Action (NPoA): Theme 1: Support and implementation of CBRM and specifically, the scaling up of CBRM in Solomon Islands. Most of the principles given in this document are derived from experiences in coastal communities and ecosystems as, until relatively recently, these have received most attention in Solomon Islands resource management. It is recognized however that the majority of these principles will be applicable to both coastal and terrestrial initiatives. This document synthesizes information provided by stakeholders at the October 2010 workshop and covers some basic principles of engagement and implementation that have been learned over more than twenty years of activities by the stakeholder partners in Solomon Islands. The document updates and expands on a summary of guiding principles for CBRM which was originally prepared by the Solomon Islands Locally Managed Marine Area Network (SILMMA) in 2007

    PICES Press, Vol. 9, No. 2, July 2001

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    Cover [pdf, 0.2 Mb] Climate, biodiversity and ecosystems of the North Pacific [pp. 1-2] [pdf, 0.2 Mb] The state of the western North Pacific in the second half of 2000 [pp. 3-5] [pdf, 0.8 Mb] The status of the Bering Sea: June – December 2000 [pp. 6-7] [pdf, 1.5 Mb] The state of the eastern North Pacific since autumn 2000 [p. 8] [pdf, 0.3 Mb] Korean Yellow Sea Large Marine Ecosystem Program [pp. 9-12] [pdf, 0.5 Mb] Past and ongoing Mexican ecosystem research in the northeast Pacific Ocean [pp. 13-15] [pdf, 0.3 Mb] Vera Alexander [pp. 16-19] [pdf, 1.0 Mb] North Pacific CO2 data for the new millennium [pp. 20-21] [pdf, 0.3 Mb] PICES Higher Trophic Level Modelling Workshop [pp. 22-23] [pdf, 0.4 Mb] Argo Science Team 3rd Meeting (AST-3) [pp. 24-25] [pdf, 0.3 Mb] 2001 coast ocean / salmon ecosystem event [p. 26-27] [pdf, 0.3 Mb] Shifts in zooplankton abundance and species composition off central Oregon and southwestern British Columbia [pp. 28-29] [pdf, 0.3 Mb] The CLIVAR - Pacific Workshop [p. 30] [pdf, 0.2 Mb] PICES dialogue with Mexican scientists [p. 31] [pdf, 0.2 Mb] Announcements [p. 32] [pdf, 0.2 Mb

    U.S. Law of the Sea cruise to map the foot of the slope and 2500-m isobath of the US Arctic Ocean margin, cruise report for 2009

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    U.S. Law of the Sea cruise to map the foot of the slope and 2500-m isobath of the US Arctic Ocean margin CRUISES HE-0905 August 7 to September 16, 2009 Barrow, AK to Barrow, A

    Multimodel inference to quantify the relative importance of abiotic factors in the population dynamics of marine zooplankton

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    The effect of multiple stressors on marine ecosystems remains poorly understood and most of the knowledge available is related to phytoplankton. To partly address this knowledge gap, we tested if combining multimodel inference with generalized additive modelling could quantify the relative contribution of environmental variables on the population dynamics of a zooplankton species in the Belgian part of the North Sea. Hence, we have quantified the relative contribution of oceanographic variables (e.g. water temperature, salinity, nutrient concentrations, and chlorophyll a concentrations) and anthropogenic chemicals (i.e. polychlorinated biphenyls) to the density of Acartia clausi. We found that models with water temperature and chlorophyll a concentration explained ca. 73% of the population density of the marine copepod. Multimodel inference in combination with regression-based models are a generic way to disentangle and quantify multiple stressor-induced changes in marine ecosystems. Future-oriented simulations of copepod densities suggested increased copepod densities under predicted environmental changes

    U.S. Law of the Sea Cruise to Map and Sample the US Arctic Ocean Margin

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    U.S. Law of the Sea cruise to map and sample the US Arctic Ocean margin CRUISE HEALY 1202 August 25 to September 27, 2012 Barrow, AK to Dutch Harbor, A
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