Advances in the therapeutic use of mammalian target of rapamycin (mTOR) inhibitors in dermatology.

PubMed

Fogel, Alexander L; Hill, Sharleen; Teng, Joyce M C

2015-05-01

Significant developments in the use of mammalian target of rapamycin (mTOR) inhibitors (mTORIs) as immunosuppressant and antiproliferative agents have been made. Recent advances in the understanding of the mTOR signaling pathway and its downstream effects on tumorigenesis and vascular proliferation have broadened the clinical applications of mTORIs in many challenging disorders such as tuberous sclerosis complex, pachyonychia congenita, complex vascular anomalies, and inflammatory dermatoses. Systemic mTORI therapy has shown benefits in these areas, but is associated with significant side effects that sometimes necessitate drug holidays. To mitigate the side effects of systemic mTORIs for dermatologic applications, preliminary work to assess the potential of percutaneous therapy has been performed, and the evidence suggests that percutaneous delivery of mTORIs may allow for effective long-term therapy while avoiding systemic toxicities. Additional large placebo-controlled, double-blinded, randomized studies are needed to assess the efficacy, safety, duration, and tolerability of topical treatments. The objective of this review is to provide updated information on the novel use of mTORIs in the management of many cutaneous disorders. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

KAM Tori Construction Algorithms

NASA Astrophysics Data System (ADS)

Wiesel, W.

In this paper we evaluate and compare two algorithms for the calculation of KAM tori in Hamiltonian systems. The direct fitting of a torus Fourier series to a numerically integrated trajectory is the first method, while an accelerated finite Fourier transform is the second method. The finite Fourier transform, with Hanning window functions, is by far superior in both computational loading and numerical accuracy. Some thoughts on applications of KAM tori are offered.

Computation of Quasi-Periodic Normally Hyperbolic Invariant Tori: Algorithms, Numerical Explorations and Mechanisms of Breakdown

NASA Astrophysics Data System (ADS)

Canadell, Marta; Haro, Àlex

2017-12-01

We present several algorithms for computing normally hyperbolic invariant tori carrying quasi-periodic motion of a fixed frequency in families of dynamical systems. The algorithms are based on a KAM scheme presented in Canadell and Haro (J Nonlinear Sci, 2016. doi: 10.1007/s00332-017-9389-y), to find the parameterization of the torus with prescribed dynamics by detuning parameters of the model. The algorithms use different hyperbolicity and reducibility properties and, in particular, compute also the invariant bundles and Floquet transformations. We implement these methods in several 2-parameter families of dynamical systems, to compute quasi-periodic arcs, that is, the parameters for which 1D normally hyperbolic invariant tori with a given fixed frequency do exist. The implementation lets us to perform the continuations up to the tip of the quasi-periodic arcs, for which the invariant curves break down. Three different mechanisms of breakdown are analyzed, using several observables, leading to several conjectures.

KAM Tori for 1D Nonlinear Wave Equationswith Periodic Boundary Conditions

NASA Astrophysics Data System (ADS)

Chierchia, Luigi; You, Jiangong

In this paper, one-dimensional (1D) nonlinear wave equations with periodic boundary conditions are considered; V is a periodic smooth or analytic function and the nonlinearity f is an analytic function vanishing together with its derivative at u≡0. It is proved that for ``most'' potentials V(x), the above equation admits small-amplitude periodic or quasi-periodic solutions corresponding to finite dimensional invariant tori for an associated infinite dimensional dynamical system. The proof is based on an infinite dimensional KAM theorem which allows for multiple normal frequencies.

Resonance phenomena in a time-dependent, three-dimensional model of an idealized eddy

NASA Astrophysics Data System (ADS)

Rypina, I. I.; Pratt, L. J.; Wang, P.; Äe; -zgökmen, T. M.; Mezic, I.

2015-08-01

We analyze the geometry of Lagrangian motion and material barriers in a time-dependent, three-dimensional, Ekman-driven, rotating cylinder flow, which serves as an idealization for an isolated oceanic eddy and other overturning cells with cylindrical geometry in the ocean and atmosphere. The flow is forced at the top through an oscillating upper lid, and the response depends on the frequency and amplitude of lid oscillations. In particular, the Lagrangian geometry changes near the resonant tori of the unforced flow, whose frequencies are rationally related to the forcing frequencies. Multi-scale analytical expansions are used to simplify the flow in the vicinity of resonant trajectories and to investigate the resonant flow geometries. The resonance condition and scaling can be motivated by simple physical argument. The theoretically predicted flow geometries near resonant trajectories have then been confirmed through numerical simulations in a phenomenological model and in a full solution of the Navier-Stokes equations.

Extending Whole-earth Tectonics To The Terrestrial Planets

NASA Astrophysics Data System (ADS)

Baker, V. R.; Maruyama, S.; Dohm, J. M.

Based on the need to explain a great many geological and geophysical anomalies on Mars, and stimulated by the new results from the Mars Global Surveyor Mission, we propose a conceptual model of whole-EARTH (Episodic Annular Revolving Thermal Hydrologic) tectonics for the long-term evolution of terrestrial planets. The theory emphasizes (1) the importance of water in planetary evolution, and (2) the physi- cal transitions in modes of mantle convection in relation to planetary heat produc- tion. Depending on their first-order geophysical parameters and following accretion and differentiation from volatile-rich planetessimals, terrestrial planets should evolve through various stages of mantle convection, including magma ocean, plate tectonic, and stagnant lid processes. If a water ocean is able to condense from the planet's early steam atmosphere, an early regime of plate tectonics will follow the initial magma ocean. This definitely happened on earth, probably on Mars, and possibly on Venus. The Mars history led to transfer of large amounts of water to the mantle during the pe- riod of heavy bombardment. Termination of plate tectonics on Mars during the heavy bombardment period led to initiation of superplumes at Tharsis and Elysium, where long-persistent volcanism and water outbursts dominated much of later Martian his- tory. For Venus, warming of the early sun made the surface ocean unstable, eliminating its early plate-tectonic regime. Although Venus now experiences stagnant-lid convec- tion with episodic mantle overturns, the water subducted to its lower mantle during the ancient plate-tectonic regime manifests itself in the initation of volatile-rich plumes that dominate its current tectonic regime.

Media Embeds: Balancing Operations Security with Public Need to Know

DTIC Science & Technology

2009-04-01

Journalism Review, January/February 2002. 2 Torie Clarke, Lipstick on a Pig (New York, N.Y.: Free Press, 2006), 17-24. 3 Richard K. Wright...voice-clarke.asp. 15 Torie Clarke, Lipstick on a Pig (New York, N.Y.: Free Press, 2006), 94. 16 Department of Defense, “Seminar on Coverage of the...20 Torie Clarke, Lipstick on a Pig (New York, N.Y.: Free Press, 2006), 54. 21 Message, 101900Z FEB 03, Department of Defense to Public Affairs, 10

Aortic root dilation in kidney transplant recipients.

PubMed

Obremska, Marta; Boratyńska, Maria; Szymczak, Maciej; Zyśko, Dorota; Płonek, Tomasz; Goździk, Anna; Klinger, Marian

2018-05-30

INTRODUCTION Aortic root (AoR) dilation is associated with cardiac damage and higher cardiovascular risk. Cardiovascular disease is the most common cause of death in patients after kidney transplantation (KTx ). OBJECTIVES The aim of this study was to assess the prevalence of enlarged AoR diameter in KTx recipients. Patients with bicuspid aortic valve, significant valvular disease, or evidence of connective tissue disorder were excluded. PATIENTS AND METHODS A total of 87 KTx recipients were divided into 2 groups depending on immunosuppressive regimen: 41 patients receiving mammalian target of rapamycin inhibitors (mTORi) and 46 patients treated with calcineurin inhibitors (CNIs). In all patients, echocardiography was performed, laboratory and clinical markers of cardiovascular risk were assessed, and the AoR diameter was calculated. RESULTS There were no differences between groups in age, sex, body surface area, body mass index, frequency of diabetes, hypertension, dyslipidemia, time after replacement therapy, creatinine levels, and estimated glomerular filtration rate. In the CNI group, the observed and calculated AoR diameters were similar (P = 0.8). In the mTORi group, the observed AoR diameter was higher than the calculated one (P = 0.002). The concentric and eccentric left ventricular hypertrophy was similar in both groups (P = 0.12 and P = 0.69, respectively). In the stepwise regression analysis, the AoR diameter was associated with body surface area and mTORi treatment. CONCLUSIONS KTx recipients have a high prevalence of AoR dilation. Immunosuppressive regimen based on mTORi increases the incidence of AoR enlargement.

A comparative ultrastructural study of pit membranes with plasmodesmata associated thickenings in four angiosperm species.

PubMed

Rabaey, David; Lens, Frederic; Huysmans, Suzy; Smets, Erik; Jansen, Steven

2008-11-01

Recent micromorphological observations of angiosperm pit membranes have extended the number and range of taxa with pseudo-tori in tracheary elements. This study investigates at ultrastructural level (TEM) the development of pseudo-tori in the unrelated Malus yunnanensis, Ligustrum vulgare, Pittosporum tenuifolium, and Vaccinium myrtillus in order to determine whether these plasmodesmata associated thickenings have a similar developmental pattern across flowering plants. At early ontogenetic stages, the formation of a primary thickening was observed, resulting from swelling of the pit membrane in fibre-tracheids and vessel elements. Since plasmodesmata appear to be frequently, but not always, associated with these primary pit membrane thickenings, it remains unclear which ultrastructural characteristics control the formation of pseudo-tori. At a very late stage during xylem differentiation, a secondary thickening is deposited on the primary pit membrane thickening. Plasmodesmata are always associated with pseudo-tori at these final developmental stages. After autolysis, the secondary thickening becomes electron-dense and persistent, while the primary thickening turns transparent and partially or entirely dissolves. The developmental patterns observed in the species studied are similar and agree with former ontogenetic studies in Rosaceae, suggesting that pseudo-tori might be homologous features across angiosperms.

Perfect fluid tori orbiting Kehagias-Sfetsos naked singularities

NASA Astrophysics Data System (ADS)

Stuchlík, Z.; Pugliese, D.; Schee, J.; Kučáková, H.

2015-09-01

We construct perfect fluid tori in the field of the Kehagias-Sfetsos (K-S) naked singularities. These are spherically symmetric vacuum solutions of the modified Hořava quantum gravity, characterized by a dimensionless parameter ω M^2, combining the gravitational mass parameter M of the spacetime with the Hořava parameter ω reflecting the role of the quantum corrections. In dependence on the value of ω M^2, the K-S naked singularities demonstrate a variety of qualitatively different behavior of their circular geodesics that is fully reflected in the properties of the toroidal structures, demonstrating clear distinction to the properties of the torii in the Schwarzschild spacetimes. In all of the K-S naked singularity spacetimes the tori are located above an "antigravity" sphere where matter can stay in a stable equilibrium position, which is relevant for the stability of the orbiting fluid toroidal accretion structures. The signature of the K-S naked singularity is given by the properties of marginally stable tori orbiting with the uniform distribution of the specific angular momentum of the fluid, l= const. In the K-S naked singularity spacetimes with ω M^2 > 0.2811, doubled tori with the same l= const can exist; mass transfer between the outer torus and the inner one is possible under appropriate conditions, while only outflow to the outer space is allowed in complementary conditions. In the K-S spacetimes with ω M^2 < 0.2811, accretion from cusped perfect fluid tori is not possible due to the non-existence of unstable circular geodesics.

Exploring potential Pluto-generated neutral tori

NASA Astrophysics Data System (ADS)

Smith, Howard T.; Hill, Matthew; KollMann, Peter; McHutt, Ralph

2015-11-01

The NASA New Horizons mission to Pluto is providing unprecedented insight into this mysterious outer solar system body. Escaping molecular nitrogen is of particular interest and possibly analogous to similar features observed at moons of Saturn and Jupiter. Such escaping N2 has the potential of creating molecular nitrogen and N (as a result of molecular dissociation) tori or partial toroidal extended particle distributions. The presence of these features would present the first confirmation of an extended toroidal neutral feature on a planetary scale in our solar system. While escape velocities are anticipated to be lower than those at Enceladus, Io or even Europa, particle lifetimes are much longer in Pluto’s orbit because as a result of much weaker solar interaction processes along Pluto’s orbit (on the order of tens of years). Thus, with a ~248 year orbit, Pluto may in fact be generating an extended toroidal feature along it orbit.For this work, we modify and apply our 3-D Monte Carlo neutral torus model (previously used at Saturn, Jupiter and Mercury) to study/analyze the theoretical possibility and scope of potential Pluto-generated neutral tori. Our model injects weighted particles and tracks their trajectories under the influence of all gravitational fields with interactions with other particles, solar photons and Pluto collisions. We present anticipated N2 and N tori based on current estimates of source characterization and environmental conditions. We also present an analysis of sensitivity to assumed initial conditions. Such results can provide insight into the Pluto system as well as valuable interpretation of New Horizon’s observational data.

Neutron tori around Kerr black holes

NASA Technical Reports Server (NTRS)

Witt, H. J.; Jaroszynski, M.; Haensel, P.; Paczynski, B.; Wambsganss, J.

1994-01-01

Models of stationary, axisymmetric, non-self-gravitating tori around stellar mass Kerr black holes are calculated. Such objects may form as a result of a merger between two neutron stars, a neutron star and a stellar mass black hole, or a 'failed supernova' collapse of a single rapidly rotating star. We explore a large range of parameters: the black hole mass and angular momentum, the torus mass, angular momentum and entropy. Physical conditions within the tori are similar to those in young and hot neutron stars, but their topology is different, and the range of masses and energies is much larger.

Dynamics of Axially Symmetric Perturbed Hamiltonians in 1:1:1 Resonance

NASA Astrophysics Data System (ADS)

Carrasco, D.; Palacián, J. F.; Vidal, C.; Vidarte, J.; Yanguas, P.

2018-03-01

We study the dynamics of a family of perturbed three-degree-of-freedom Hamiltonian systems which are in 1:1:1 resonance. The perturbation consists of axially symmetric cubic and quartic arbitrary polynomials. Our analysis is performed by normalisation, reduction and KAM techniques. Firstly, the system is reduced by the axial symmetry, and then, periodic solutions and KAM 3-tori of the full system are determined from the relative equilibria. Next, the oscillator symmetry is extended by normalisation up to terms of degree 4 in rectangular coordinates; after truncation of higher orders and reduction to the orbit space, some relative equilibria are established and periodic solutions and KAM 3-tori of the original system are obtained. As a third step, the reduction in the two symmetries leads to a one-degree-of-freedom system that is completely analysed in the twice reduced space. All the relative equilibria together with the stability and parametric bifurcations are determined. Moreover, the invariant 2-tori (related to the critical points of the twice reduced space), some periodic solutions and the KAM 3-tori, all corresponding to the full system, are established. Additionally, the bifurcations of equilibria occurring in the twice reduced space are reconstructed as quasi-periodic bifurcations involving 2-tori and periodic solutions of the full system.

The Existence of Periodic Orbits and Invariant Tori for Some 3-Dimensional Quadratic Systems

PubMed Central

Jiang, Yanan; Han, Maoan; Xiao, Dongmei

2014-01-01

We use the normal form theory, averaging method, and integral manifold theorem to study the existence of limit cycles in Lotka-Volterra systems and the existence of invariant tori in quadratic systems in ℝ3. PMID:24982980

Chenciner bubbles and torus break-up in a periodically forced delay differential equation

NASA Astrophysics Data System (ADS)

Keane, A.; Krauskopf, B.

2018-06-01

We study a generic model for the interaction of negative delayed feedback and periodic forcing that was first introduced by Ghil et al (2008 Nonlinear Process. Geophys. 15 417–33) in the context of the El Niño Southern Oscillation climate system. This model takes the form of a delay differential equation and has been shown in previous work to be capable of producing complicated dynamics, which is organised by resonances between the external forcing and dynamics induced by feedback. For certain parameter values, we observe in simulations the sudden disappearance of (two-frequency dynamics on) tori. This can be explained by the folding of invariant tori and their associated resonance tongues. It is known that two smooth tori cannot simply meet and merge; they must actually break up in complicated bifurcation scenarios that are organised within so-called resonance bubbles first studied by Chenciner. We identify and analyse such a Chenciner bubble in order to understand the dynamics at folds of tori. We conduct a bifurcation analysis of the Chenciner bubble by means of continuation software and dedicated simulations, whereby some bifurcations involve tori and are detected in appropriate two-dimensional projections associated with Poincaré sections. We find close agreement between the observed bifurcation structure in the Chenciner bubble and a previously suggested theoretical picture. As far as we are aware, this is the first time the bifurcation structure associated with a Chenciner bubble has been analysed in a delay differential equation and, in fact, for a flow rather than an explicit map. Following our analysis, we briefly discuss the possible role of folding tori and Chenciner bubbles in the context of tipping.

Development of Ocean-Bottom Seismograph in Taiwan

NASA Astrophysics Data System (ADS)

Chang, H.; Jang, J. P.; Chen, P.; Lin, C. R.; Kuo, B. Y.; Wang, C. C.; Kim, K. H.; Lin, P. P.

2016-12-01

Yardbird-20s, one type of Ocean-Bottom Seismograph (OBS), is fabricated by Taiwan Ocean Research Institute (TORI), the Institute of Earth Science of Academia Sinica and the Institute of Undersea Technology of the National Sun Yat-Sen University in Taiwan. Yardbirds can be deployed up to 5000m deep for up to 15 months. The total weight with anchor in the air is about 170Kg. The rising and sinking rate is about 0.8 m/s. We utilized ultra-low power micro control unit (MCU) and SD card to design a data logger. The sensors are three of 4.5Hz geophones that were extended the lower frequency response to 20 sec. The sensor module also includes the leveling system, which is design by dual-axis DC motor-driven module to level the vertical component to be less than 0.1 degree with respect to the gravity. Yardbirds have been successfully deployed and recovered in several research cruises in Taiwan and Korea. In this study, we'll also display the data quality and power spectral density (PSD) calculations, probability density function (PDF) plots and from the Yardbirds that deployed and recovered in the East Sea near sough-east of Korea.

Dynamics of oscillating relativistic tori around Kerr black holes

NASA Astrophysics Data System (ADS)

Zanotti, Olindo; Font, José A.; Rezzolla, Luciano; Montero, Pedro J.

2005-02-01

We present a comprehensive numerical study of the dynamics of relativistic axisymmetric accretion tori with a power-law distribution of specific angular momentum orbiting in the background space-time of a Kerr black hole. By combining general relativistic hydrodynamics simulations with a linear perturbative approach we investigate the main dynamical properties of these objects over a large parameter space. The astrophysical implications of our results extend and improve two interesting results that have been recently reported in the literature. First, the induced quasi-periodic variation of the mass quadrupole moment makes relativistic tori of nuclear matter densities, as those formed during the last stages of binary neutron star mergers, promising sources of gravitational radiation, potentially detectable by interferometric instruments. Secondly, p-mode oscillations in relativistic tori of low rest-mass densities could be used to explain high-frequency quasi-periodic oscillations observed in X-ray binaries containing a black hole candidate under conditions more generic than those considered so far.

X-Ray Absorption, Nuclear Infrared Emission, and Dust Covering Factors of AGNs: Testing Unification Schemes

NASA Astrophysics Data System (ADS)

Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X.; Asensio Ramos, A.; Watson, M. G.; Blain, A.; Caccianiga, A.; Ballo, L.; Braito, V.; Ramos Almeida, C.

2016-03-01

We present the distributions of the geometrical covering factors of the dusty tori (f2) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2-10 keV luminosities between 1042 and 1046 erg s-1, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1-20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f2 than type 1 AGNs. Nevertheless, ˜20% of type 1 AGNs have tori with large covering factors, while ˜23%-28% of type 2 AGNs have tori with small covering factors. Low f2 are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f2 increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f2 determine the optical appearance of an AGN and control the shape of the rest-frame ˜1-20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

[Book review] A field guide to western reptiles and amphibians (Second Edition, Revised), by Robert C. Stebbins and Roger Tory Peterson

USGS Publications Warehouse

Jennings, M.R.

1987-01-01

Review of: A Field Guide to Western Reptiles and Amphibians (Peterson Field Guides, No. 16). Robert C. Stebbins and Roger Tory Peterson. Houghton Mifflin; 2nd Revised edition (June 10, 1985). 448 pages. ISBN: 978-0395382530.

The stability of full dimensional KAM tori for nonlinear Schrödinger equation

NASA Astrophysics Data System (ADS)

Cong, Hongzi; Liu, Jianjun; Shi, Yunfeng; Yuan, Xiaoping

2018-04-01

In this paper, it is proved that the full dimensional invariant tori obtained by Bourgain [J. Funct. Anal., 229 (2005), no. 1, 62-94] is stable in a very long time for 1D nonlinear Schrödinger equation with periodic boundary conditions.

Toroidal configurations of perfect fluid in the Reissner-Nordström-(anti-)de Sitter spacetimes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kucáková, Hana; Slaný, Petr; Stuchlík, Zdenĕk, E-mail: hana.kucakova@centrum.cz, E-mail: petr.slany@fpf.slu.cz, E-mail: zdenek.stuchlik@fpf.slu.cz

Influence of cosmological constant on toroidal fluid configurations around charged spherically symmetric black holes and naked singularities is demostrated by study of perfect-fluid tori with uniform distribution of specific angular momentum orbiting in the Reissner-Nordström-(anti-)de Sitter spacetimes. Toroidal configurations are allowed only in the spacetimes admitting existence of stable circular geodesics. Configurations with marginally closed equipotential (equipressure) surfaces crossing itself in a cusp allow accretion (through the inner cusp) and/or excretion (through the outer cusp) of matter from the toroidal configuration. Detailed classification of the Reissner-Nordström-(anti-)de Sitter spacetimes according to properties of the marginally stable tori is given. It ismore » demonstrated that in the Reissner-Nordström-de Sitter naked-singularity spacetimes an interesting phenomenon of doubled tori can exist enabling exchange of matter between two tori in both inward and outward directions. In naked-singularity spacetimes the accretion onto the central singularity is impossible due to existence of a potential barrier.« less

Fabrication of the HIAD Large-Scale Demonstration Assembly and Upcoming Mission Applications

NASA Technical Reports Server (NTRS)

Swanson, G. T.; Johnson, R. K.; Hughes, S. J.; Dinonno, J. M.; Cheatwood, F M.

2017-01-01

Over a decade of work has been conducted in the development of NASAs Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology. This effort has included multiple ground test campaigns and flight tests culminating in the HIAD projects second generation (Gen-2) deployable aeroshell system and associated analytical tools. NASAs HIAD project team has developed, fabricated, and tested inflatable structures (IS) integrated with flexible thermal protection system (F-TPS), ranging in diameters from 3-6m, with cone angles of 60 and 70 deg.In 2015, United Launch Alliance (ULA) announced that they will use a HIAD (10-12m) as part of their Sensible, Modular, Autonomous Return Technology (SMART) for their upcoming Vulcan rocket. ULA expects SMART reusability, coupled with other advancements for Vulcan, will substantially reduce the cost of access to space. The first booster engine recovery via HIAD is scheduled for 2024. To meet this near-term need, as well as future NASA applications, the HIAD team is investigating taking the technology to the 10-15m diameter scale.In the last year, many significant development and fabrication efforts have been accomplished, culminating in the construction of a large-scale inflatable structure demonstration assembly. This assembly incorporated the first three tori for a 12m Mars Human-Scale Pathfinder HIAD conceptual design that was constructed with the current state of the art material set. Numerous design trades and torus fabrication demonstrations preceded this effort. In 2016, three large-scale tori (0.61m cross-section) and six subscale tori (0.25m cross-section) were manufactured to demonstrate fabrication techniques using the newest candidate material sets. These tori were tested to evaluate durability and load capacity. This work led to the selection of the inflatable structures third generation (Gen-3) structural liner. In late 2016, the three tori required for the large-scale demonstration assembly were fabricated, and then integrated in early 2017. The design includes provisions to add the remaining four tori necessary to complete the assembly of the 12m Human-Scale Pathfinder HIAD in the event future project funding becomes available.This presentation will discuss the HIAD large-scale demonstration assembly design and fabrication per-formed in the last year including the precursor tori development and the partial-stack fabrication. Potential near-term and future 10-15m HIAD applications will also be discussed.

Fabrication of the HIAD Large-Scale Demonstration Assembly

NASA Technical Reports Server (NTRS)

Swanson, G. T.; Johnson, R. K.; Hughes, S. J.; DiNonno, J. M.; Cheatwood, F. M.

2017-01-01

Over a decade of work has been conducted in the development of NASA's Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology. This effort has included multiple ground test campaigns and flight tests culminating in the HIAD projects second generation (Gen-2) deployable aeroshell system and associated analytical tools. NASAs HIAD project team has developed, fabricated, and tested inflatable structures (IS) integrated with flexible thermal protection system (F-TPS), ranging in diameters from 3-6m, with cone angles of 60 and 70 deg.In 2015, United Launch Alliance (ULA) announced that they will use a HIAD (10-12m) as part of their Sensible, Modular, Autonomous Return Technology (SMART) for their upcoming Vulcan rocket. ULA expects SMART reusability, coupled with other advancements for Vulcan, will substantially reduce the cost of access to space. The first booster engine recovery via HIAD is scheduled for 2024. To meet this near-term need, as well as future NASA applications, the HIAD team is investigating taking the technology to the 10-15m diameter scale. In the last year, many significant development and fabrication efforts have been accomplished, culminating in the construction of a large-scale inflatable structure demonstration assembly. This assembly incorporated the first three tori for a 12m Mars Human-Scale Pathfinder HIAD conceptual design that was constructed with the current state of the art material set. Numerous design trades and torus fabrication demonstrations preceded this effort. In 2016, three large-scale tori (0.61m cross-section) and six subscale tori (0.25m cross-section) were manufactured to demonstrate fabrication techniques using the newest candidate material sets. These tori were tested to evaluate durability and load capacity. This work led to the selection of the inflatable structures third generation (Gen-3) structural liner. In late 2016, the three tori required for the large-scale demonstration assembly were fabricated, and then integrated in early 2017. The design includes provisions to add the remaining four tori necessary to complete the assembly of the 12m Human-Scale Pathfinder HIAD in the event future project funding becomes available.This presentation will discuss the HIAD large-scale demonstration assembly design and fabrication per-formed in the last year including the precursor tori development and the partial-stack fabrication. Potential near-term and future 10-15m HIAD applications will also be discussed.

Roger Tory Peterson Institute Links Interdisciplinary Nature Studies to Increased Community Understanding. Rural Trust Featured Project.

ERIC Educational Resources Information Center

Null, Elizabeth Higgins

The Roger Tory Peterson Institute (Jamestown, New York) has been sparking a regional revival in K-12 nature studies and attracting attention from educators across America. Through summer training sessions and workshops, the Institute introduces multidisciplinary teams of teachers and community members to empirical research techniques for observing…

mTOR inhibitor-induced interstitial lung disease in cancer patients: Comprehensive review and a practical management algorithm.

PubMed

Willemsen, Annelieke E C A B; Grutters, Jan C; Gerritsen, Winald R; van Erp, Nielka P; van Herpen, Carla M L; Tol, Jolien

2016-05-15

Mammalian target of rapamycin inhibitors (mTORi) have clinically significant activity against various malignancies, such as renal cell carcinoma and breast cancer, but their use can be complicated by several toxicities. Interstitial lung disease (ILD) is an adverse event of particular importance. Mostly, mTORi-induced ILD remains asymptomatic or mildly symptomatic, but it can also lead to severe morbidity and even mortality. Therefore, careful diagnosis and management of ILD is warranted. The reported incidence of mTORi-induced ILD varies widely because of a lack of uniform diagnostic criteria and active surveillance. Because of the nonspecific clinical features, a broad differential diagnosis that includes (opportunistic) infections should be considered in case of suspicion of mTORi-induced ILD. The exact mechanism or interplay of mechanisms leading to the development of ILD remains to be defined. Suggested mechanisms are either a direct toxic effect or immune-mediated mechanisms, considering mTOR inhibitors have several effects on the immune system. The clinical course of ILD varies widely and is difficult to predict. Consequently, the discrimination between when mTOR inhibitors can be continued safely and when discontinuation is indicated is challenging. In this review, we give a comprehensive review of the incidence, clinical presentation and pathophysiology of mTORi-induced ILD in cancer patients. We present newly developed diagnostic criteria for ILD, which include clinical symptoms as well as basic pulmonary function tests and radiological abnormalities. In conjunction with these diagnostic criteria, we provide a detailed and easily applicable clinical management algorithm. © 2015 UICC.

A Measure of Total Research Impact Independent of Time and Discipline

PubMed Central

Pepe, Alberto; Kurtz, Michael J.

2012-01-01

Authorship and citation practices evolve with time and differ by academic discipline. As such, indicators of research productivity based on citation records are naturally subject to historical and disciplinary effects. We observe these effects on a corpus of astronomer career data constructed from a database of refereed publications. We employ a simple mechanism to measure research output using author and reference counts available in bibliographic databases to develop a citation-based indicator of research productivity. The total research impact (tori) quantifies, for an individual, the total amount of scholarly work that others have devoted to his/her work, measured in the volume of research papers. A derived measure, the research impact quotient (riq), is an age-independent measure of an individual's research ability. We demonstrate that these measures are substantially less vulnerable to temporal debasement and cross-disciplinary bias than the most popular current measures. The proposed measures of research impact, tori and riq, have been implemented in the Smithsonian/NASA Astrophysics Data System. PMID:23144782

Mechanisms of Stochastic Diffusion of Energetic Ions in Spherical Tori

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ya.I. Kolesnichenko; R.B. White; Yu.V. Yakovenko

Stochastic diffusion of the energetic ions in spherical tori is considered. The following issues are addressed: (I) Goldston-White-Boozer diffusion in a rippled field; (ii) cyclotron-resonance-induced diffusion caused by the ripple; (iii) effects of non-conservation of the magnetic moment in an axisymmetric field. It is found that the stochastic diffusion in spherical tori with a weak magnetic field has a number of peculiarities in comparison with conventional tokamaks; in particular, it is characterized by an increased role of mechanisms associated with non-conservation of the particle magnetic moment. It is concluded that in current experiments on National Spherical Torus eXperiment (NSTX) themore » stochastic diffusion does not have a considerable influence on the confinement of energetic ions.« less

Impact of mTOR-I on fertility and pregnancy: state of the art and review of the literature.

PubMed

Framarino-dei-Malatesta, Marialuisa; Derme, Martina; Manzia, Tommaso M; Iaria, Giuseppe; De Luca, Linda; Fazzolari, Laura; Napoli, Angela; Berloco, Pasquale; Patel, Timil; Orlando, Giuseppe; Tisone, Giuseppe

2013-08-01

Successful transplantation should lead to improvements in sexual function and sex hormone disturbances in both men and women, but immunosuppressive drugs may interfere with hormone metabolism. In this regard, several studies have showed a potential negative effect of mTOR inhibitors (mTORi) on male gonadal function, while their role in the female patients is not well documented in the literature. Successful pregnancy is possible after solid organ transplantation. The fetal effects of mTORi are still poorly defined but they seem not to represent an absolute contraindication for pregnancy. The aim of our study would be to review the impact of mTORi on fertility and pregnancy in order to have a clearer picture about their possible use after organ transplantation.

X-RAY ABSORPTION, NUCLEAR INFRARED EMISSION, AND DUST COVERING FACTORS OF AGNs: TESTING UNIFICATION SCHEMES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.

2016-03-10

We present the distributions of the geometrical covering factors of the dusty tori (f{sub 2}) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2–10 keV luminosities between 10{sup 42} and 10{sup 46} erg s{sup −1}, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1–20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Opticallymore » classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f{sub 2} than type 1 AGNs. Nevertheless, ∼20% of type 1 AGNs have tori with large covering factors, while ∼23%–28% of type 2 AGNs have tori with small covering factors. Low f{sub 2} are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f{sub 2} increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f{sub 2} determine the optical appearance of an AGN and control the shape of the rest-frame ∼1–20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.« less

1991 Nature Educators of the Year Recognized by the Roger Tory Peterson Institute of Natural History. Award Winners and Noteworthy Programs.

ERIC Educational Resources Information Center

Baldwin, Mark, Comp.; Seaberg, Anita, Comp.

The Roger Tory Peterson Institute's Nature Educators of the Year program recognizes teachers who have successfully implemented education programs that effectively connect children to nature, and that can be replicated by others. Two awards of $1,000 each were given in 1991. One of the recipients, Steven Prchal, is executive director of Sonoran…

Evaluation of cryopreserved stallion semen from Tori and Estonian breeds using CASA and flow cytometry.

PubMed

Kavak, A; Johannisson, A; Lundeheim, N; Rodriguez-Martinez, H; Aidnik, M; Einarsson, S

2003-04-15

Methods to evaluate the quality of frozen-thawed stallion semen are still needed, particularly those considering the sperm function. The present study evaluated sperm motility, membrane and acrosome integrity and the capacitation status of frozen-thawed spermatozoa from seven Tori and six Estonian breed stallions by way of computer assisted sperm analysis (CASA), a triple fluorophore stain combination and Merocyanine 540, respectively, the latter ones using flow cytometry. Two ejaculates from each stallion were cryopreserved using the Hannover method in 0.5 ml plastic straws. Two straws per ejaculate per stallion were thawed at 37 degrees C for 30s. Motility was analysed with CASA immediately after thawing, while for flow cytometry spermatozoa were cleansed by 70:40% Percoll discontinuous density gradient separation before analysed for sperm viability, acrosome integrity (stained with SNARF, PI and FITC-PSA) and capacitation status (stained with Merocyanine 540/Yo-Pro-1). Results (as least square means) were as follows: the motility of frozen-thawed semen was 43.4% for Tori stallions and 42.3% for Estonian stallions (P>0.05). After Percoll separation 79.3% of the spermatozoa from Tori stallions had intact acrosomes and 1.7% of them showed early signs of capacitation. The same parameters for Estonian stallions were 84.5 and 2.3%, respectively. There were no statistically significant differences between breeds or ejaculates within breed for any evaluated parameter. We conclude that triple staining and flow cytometry are valuable techniques to evaluate frozen-thawed stallion spermatozoa, and that no differences in quality of frozen semen were registered between Tori and Estonian breed stallions, allowing implementation of this technology in the Estonian horse population.

Satellite tori at Saturn

NASA Technical Reports Server (NTRS)

Richardson, J. D.; Eviatar, A.; Siscoe, G. L.

1986-01-01

The inner satellites of Saturn are icy bodies imbedded in a plasma environment in which they are continuously bombarded by energetic ions, corotating plasma, and solar radiation. Laboratory sputtering experiments indicate that this should result in the injection of substantial amounts of neutral H, H2, OH, H2O, and O2 into the magnetosphere. The atomic processes affecting these neutrals and the neutrals and ions formed from them are modeled, and the steady state neutral and ion densities expected in the plasma tori of Enceladus, Dione-Tethys, and Rhea are calculated. Comparison with observations shows that recombination can limit the Enceladus and Dione-Tethys tori to the observed densities, but that transport rates of at least 4 x 10 to the -8th Saturn radii squared/s are required to limit torus densities at Rhea to the observed values.

Computation of Quasiperiodic Normally Hyperbolic Invariant Tori: Rigorous Results

NASA Astrophysics Data System (ADS)

Canadell, Marta; Haro, Àlex

2017-12-01

The development of efficient methods for detecting quasiperiodic oscillations and computing the corresponding invariant tori is a subject of great importance in dynamical systems and their applications in science and engineering. In this paper, we prove the convergence of a new Newton-like method for computing quasiperiodic normally hyperbolic invariant tori carrying quasiperiodic motion in smooth families of real-analytic dynamical systems. The main result is stated as an a posteriori KAM-like theorem that allows controlling the inner dynamics on the torus with appropriate detuning parameters, in order to obtain a prescribed quasiperiodic motion. The Newton-like method leads to several fast and efficient computational algorithms, which are discussed and tested in a companion paper (Canadell and Haro in J Nonlinear Sci, 2017. doi: 10.1007/s00332-017-9388-z), in which new mechanisms of breakdown are presented.

Educational Reform in England and the United States: The Significance of Contextual Differences.

ERIC Educational Resources Information Center

Swanson, Austin D.

1995-01-01

Explores British and American policy analysts' disparate perceptions about utility of major educational reforms (school-based management, school choice, and national standards). The Tories got carried away with their ideological agenda and have alienated teachers and the public. American educators are debating centralization/decentralization, but…

A Study of the Integration of Military Personnel into the Fort Gordon Occupational Health Program.

DTIC Science & Technology

1980-05-01

manpower data should be readily available to determine resource requirements. The other limiting factors which could bear on the problem include both...physical examinations and appropriate eyeglasses are provided based on both visual and safety requirements. Hazard inven- tories in areas jointly worked by

Actors: A Model of Concurrent Computation in Distributed Systems.

DTIC Science & Technology

1985-06-01

Artificial Intelligence Labora- tory of the Massachusetts Institute of Technology. Support for the labora- tory’s aritificial intelligence research is...RD-A157 917 ACTORS: A MODEL OF CONCURRENT COMPUTATION IN 1/3- DISTRIBUTED SY𔃿TEMS(U) MASSACHUSETTS INST OF TECH CRMBRIDGE ARTIFICIAL INTELLIGENCE ...Computation In Distributed Systems Gui A. Aghai MIT Artificial Intelligence Laboratory Thsdocument ha. been cipp-oved I= pblicrelease and sale; itsI

On noncommutative Levi-Civita connections

NASA Astrophysics Data System (ADS)

Peterka, Mira A.; Sheu, Albert Jeu-Liang

We make some observations about Rosenberg’s Levi-Civita connections on noncommutative tori, noting the non-uniqueness of general torsion-free metric-compatible connections without prescribed connection operator for the inner *-derivations, the nontrivial curvature form of the inner *-derivations, and the validity of the Gauss-Bonnet theorem for two classes of nonconformal deformations of the flat metric on the noncommutative two-tori, including the case of noncommuting scalings along the principal directions of a two-torus.

NI-DiscoverHistory: Meta-narrative for Explanation Bounding

DTIC Science & Technology

2014-01-01

this research during the summer of 2014. 4 References [1] D. Herman, Storytelling and the Sciences of Mind. MIT Press, 2013. [2] M. Mateas and P...ASM Project NI-DiscoverHistory: Meta-narrative for Explanation Bounding Tory S. Anderson1, Swaroop Vattam2, and David Aha3 1Grad Student Researcher ...Georgia Institute of Technology; torys.anderson@gatech.edu 2NRC postdoctoral Researcher ; Navy Center for Applied Research in AI; Naval Research

Fully Numerical Methods for Continuing Families of Quasi-Periodic Invariant Tori in Astrodynamics

NASA Astrophysics Data System (ADS)

Baresi, Nicola; Olikara, Zubin P.; Scheeres, Daniel J.

2018-06-01

Quasi-periodic invariant tori are of great interest in astrodynamics because of their capability to further expand the design space of satellite missions. However, there is no general consent on what is the best methodology for computing these dynamical structures. This paper compares the performance of four different approaches available in the literature. The first two methods compute invariant tori of flows by solving a system of partial differential equations via either central differences or Fourier techniques. In contrast, the other two strategies calculate invariant curves of maps via shooting algorithms: one using surfaces of section, and one using a stroboscopic map. All of the numerical procedures are tested in the co-rotating frame of the Earth as well as in the planar circular restricted three-body problem. The results of our numerical simulations show which of the reviewed procedures should be preferred for future studies of astrodynamics systems.

On the plethora of representations arising in noncommutative quantum mechanics and an explicit construction of noncommutative 4-tori

NASA Astrophysics Data System (ADS)

Chowdhury, S. Hasibul Hassan

2017-06-01

We construct a 2-parameter family of unitarily equivalent irreducible representations of the triply extended group GNC of translations of R4 associated with a family of its 4-dimensional coadjoint orbits and show how a continuous 2-parameter family of gauge potentials emerges from these unitarily equivalent representations. We show that the Landau and the symmetric gauges of noncommutative quantum mechanics, widely used in the literature, in fact, belong to this 2-parameter family of gauges. We also provide an explicit construction of noncommutative 4-tori and compute the associated star products using the unitary dual of the group GNC that was studied at length in an earlier paper [S. H. H. Chowdhury and S. T. Ali, J. Phys. A: Math. Theor. 47, 085301 (2014)]. Finally, we construct projective modules over such noncommutative 4-tori and compute constant curvature connections on them using Rieffel's method.

Bipartisan politics and practical knowledge: advertising of public science in two London newspapers, 1695-1720.

PubMed

Wigelsworth, Jeffrey R

2008-12-01

This article explores the enticement of consumers for natural philosophy (buyers of books, audiences at public lectures and purchasers of instruments) in London between 1695 and 1720 through advertisements placed in two political newspapers. This twenty-five-year period witnessed both the birth of public science and the rage of party politics. A consideration of public science adverts within the Whig-leaning Post Man and the Tory-leaning Post Boy reveals that members of both the Whig and Tory parties were equally targeted and that natural philosophy was sold to London's reading population in bipartisan fashion. In the process of integrating natural philosophy into the wider culture through commercial sales, political allegiances were not imprinted on the advertising process. This conclusion raises questions regarding the historiographical assertion of Whig-supported public science and Tory opposition to it at the level of consumers.

Fully Numerical Methods for Continuing Families of Quasi-Periodic Invariant Tori in Astrodynamics

NASA Astrophysics Data System (ADS)

Baresi, Nicola; Olikara, Zubin P.; Scheeres, Daniel J.

2018-01-01

Quasi-periodic invariant tori are of great interest in astrodynamics because of their capability to further expand the design space of satellite missions. However, there is no general consent on what is the best methodology for computing these dynamical structures. This paper compares the performance of four different approaches available in the literature. The first two methods compute invariant tori of flows by solving a system of partial differential equations via either central differences or Fourier techniques. In contrast, the other two strategies calculate invariant curves of maps via shooting algorithms: one using surfaces of section, and one using a stroboscopic map. All of the numerical procedures are tested in the co-rotating frame of the Earth as well as in the planar circular restricted three-body problem. The results of our numerical simulations show which of the reviewed procedures should be preferred for future studies of astrodynamics systems.

A Field Guide to Competency-Based Adult Education, or How Do You Know Its a CBAE? (With Apologies to Roger Tory Peterson).

ERIC Educational Resources Information Center

Nickse, Ruth S.

Two definitions most often used by adult educators to describe competency-based adult education (CBAE) are one posited by Spady (1977) and another formulated by state adult basic education directors. The first, a "prescriptive-consensual" definition, describes conditions of a phenomenon (CBAE) and relies on the experience of acknowledged experts,…

Testing holography using lattice super-Yang-Mills theory on a 2-torus

NASA Astrophysics Data System (ADS)

Catterall, Simon; Jha, Raghav G.; Schaich, David; Wiseman, Toby

2018-04-01

We consider maximally supersymmetric SU (N ) Yang-Mills theory in Euclidean signature compactified on a flat two-dimensional torus with antiperiodic ("thermal") fermion boundary conditions imposed on one cycle. At large N , holography predicts that this theory describes certain black hole solutions in type IIA and IIB supergravity, and we use lattice gauge theory to test this. Unlike the one-dimensional quantum mechanics case where there is only the dimensionless temperature to vary, here we emphasize there are two more parameters which determine the shape of the flat torus. While a rectangular Euclidean torus yields a thermal interpretation, allowing for skewed tori modifies the holographic dual black hole predictions and results in another direction to test holography. Our lattice calculations are based on a supersymmetric formulation naturally adapted to a particular skewing. Using this we perform simulations up to N =16 with several lattice spacings for both skewed and rectangular tori. We observe the two expected black hole phases with their predicted behavior, with a transition between them that is consistent with the gravity prediction based on the Gregory-Laflamme transition.

Pulling it all together: the self-consistent distribution of neutral tori in Saturn's Magnetosphere based on all Cassini observations

NASA Astrophysics Data System (ADS)

Smith, H. T.; Richardson, J. D.

2017-12-01

Saturn's magnetosphere is unique in that the plumes from the small icy moon, Enceladus, serve at the primary source for heavy particles in Saturn's magnetosphere. The resulting co-orbiting neutral particles interact with ions, electrons, photons and other neutral particles to generate separate H2O, OH and O tori. Characterization of these toroidal distributions is essential for understanding Saturn magnetospheric sources, composition and dynamics. Unfortunately, limited direct observations of these features are available so modeling is required. A significant modeling challenge involves ensuring that either the plasma and neutral particle populations are not simply input conditions but can provide feedback to each population (i.e. are self-consistent). Jurac and Richardson (2005) executed such a self-consistent model however this research was performed prior to the return of Cassini data. In a similar fashion, we have coupled a 3-D neutral particle model (Smith et al. 2004, 2005, 2006, 2007, 2009, 2010) with a plasma transport model (Richardson 1998; Richardson & Jurac 2004) to develop a self-consistent model which is constrained by all available Cassini observations and current findings on Saturn's magnetosphere and the Enceladus plume source resulting in much more accurate neutral particle distributions. We present a new self-consistent model of the distribution of the Enceladus-generated neutral tori that is validated by all available observations. We also discuss the implications for source rate and variability.

Short term forecasting for HFSWR sea surface current mapping using artificial neural network

NASA Astrophysics Data System (ADS)

Lai, J. W.; Lu, Y. C.; Hsieh, C. M.; Liau, J. M.; Yang, W. C.

2016-02-01

Taiwan Ocean Research Institute (TORI) established the Taiwan Ocean Radar Observing System (TOROS) based on the CODAR high frequency surface wave radar (HFSWR). The TOROS is the first network having complete, contiguous HFSWR coverage of nation's coastline in the world. This network consisting of 17 SeaSonde radars offers coverage across approximately 190,000 square kilometers an area, over five times the size of Taiwan's entire land mass. In the southernmost and narrowest part of Taiwan, two 13 MHz and one 24 MHz radars were established along the NanWan Bay since June, 2014. NanWan Bay, the southern tip of Taiwan, is a southward semi-enclosed basin bounded by two capes and is open to the Luzon Strait. The distance between the two caps is around 12 km, and the distance from the northernmost point of the bay to the caps are 5 and 11 km, respectively. Strong tidal currents dominate the ocean circulation in the NanWan Bay and induce obvious upwelling of cold water that intrudes on to the shallow regions of NanWan Bay around spring tides. From late fall to early spring, the seaward wind dominated by the northeast monsoon often destratifies the water column and decreases the sea surface temperature inside the Bay (Lee et al, 1997). Furthermore, the Nanwan Bay is famous with well-developed fringing reefs distributed along the shoreline. In this area, 230 species of scleractinian corals, nine species of non-scleractinian reef-building corals, and 40 species of alcyonacean corals have been recorded (Dai, 1991). NanWan, in the shape of a beautiful arch, attracts large crowds of people to take all kinds of beach or water activities every summer. In order to improve the applicability of HFSWR ocean surface current data on search and rescue issue and evaluation of coral spawn dispersal, a short term forecasting model using artificial neural network (ANN) was developed in this study. That ocean surface current vectors obtained from tidal theory are added as inputs in artificial neural network model is found to improve prediction ability for current vectors. The optimum structure of the present ANN model for each ocean current grid is set up from examining the learning rate, moment factor, input parameters, numbers of hidden layer, learning times and input length. Results show that the ANN model have better accuracy of short-term forecasting.

Charged perfect fluid tori in strong central gravitational and dipolar magnetic fields

NASA Astrophysics Data System (ADS)

Kovář, Jiří; Slaný, Petr; Cremaschini, Claudio; Stuchlík, Zdeněk; Karas, Vladimír; Trova, Audrey

2016-06-01

We study electrically charged perfect fluid toroidal structures encircling a spherically symmetric gravitating object with Schwarzschild spacetime geometry and endowed with a dipole magnetic field. The work represents a direct continuation of our previous general-relativistic studies of electrically charged fluid in the approximation of zero conductivity, which formed tori around a Reissner-Nordström black hole or a Schwarzschild black hole equipped with a test electric charge and immersed in an asymptotically uniform magnetic field. After a general introduction of the zero-conductivity charged fluid model, we discuss a variety of possible topologies of the toroidal fluid configurations. Along with the charged equatorial tori forming interesting coupled configurations, we demonstrate the existence of the off-equatorial tori, for which the dipole type of magnetic field seems to be necessary. We focus on orbiting structures with constant specific angular momentum and on those in permanent rigid rotation. We stress that the general analytical treatment developed in our previous works is enriched here by the integrated form of the pressure equations. To put our work into an astrophysical context, we identify the central object with an idealization of a nonrotating magnetic neutron star. Constraining ranges of its parameters and also parameters of the circling fluid, we discuss a possible relevance of the studied toroidal structures, presenting along with their topology also pressure, density, temperature and charge profiles.

Zeta functions on tori using contour integration

NASA Astrophysics Data System (ADS)

Elizalde, Emilio; Kirsten, Klaus; Robles, Nicolas; Williams, Floyd

2015-12-01

A new, seemingly useful presentation of zeta functions on complex tori is derived by using contour integration. It is shown to agree with the one obtained by using the Chowla-Selberg series formula, for which an alternative proof is thereby given. In addition, a new proof of the functional determinant on the torus results, which does not use the Kronecker first limit formula nor the functional equation of the non-holomorphic Eisenstein series. As a bonus, several identities involving the Dedekind eta function are obtained as well.

Fort Independence: An Eighteenth-Century Frontier Homesite and Militia Post in South Carolina.

DTIC Science & Technology

1982-12-01

zone was designated Zone 3. The matrix was a moist , black muck with some rocks present, as well as chunks of burned and unburned logs, a 60 x 90cm...area of strong Tory sentiment, Fort ." Independence was important in maintaining South Carolina’s frontier at a critical time. The fort was burned by...Fort Independence was important in maintaining South Carolina’s frontier at a critical time. The fort was burned by Tories in early 1779

PAH Formation in O-rich Evolved Stars

NASA Astrophysics Data System (ADS)

Guzman-Ramirez, L.; Lagadec, E.; Jones, D.; Zijlstra, A. A.; Gesicki, K.

2015-08-01

Polycyclic aromatic hydrocarbons (PAHs) have been observed in O-rich planetary nebulae. This combination of oxygen-rich and carbon-rich material, known as dual-dust or mixed chemistry, is not expected to be seen around these objects. We recently proposed that PAHs could be formed from the photodissociation of CO in dense tori. Using VISIR/VLT, we spatially resolved the emission of the PAH bands and ionised emission from the [S IV] line, confirming the presence of dense central tori in all the observed O-rich objects. Furthermore, we show that for most of the objects, PAHs are located at the outer edge of these dense/compact tori, while the ionised material is mostly present in the inner parts, consistent with our hypothesis for the formation of PAHs in these systems. The presence of a dense torus has been strongly associated with the action of a central binary star and, as such, the rich chemistry seen in these regions may also be related to the formation of exoplanets in post-common-envelope binary systems.

Extensive packet excitations in FPU and Toda lattices

NASA Astrophysics Data System (ADS)

Christodoulidi, H.

2017-08-01

At low energies, the excitation of low-frequency packets of normal modes in the Fermi-Pasta-Ulam (FPU) and in the Toda model leads to exponentially localized energy profiles which resemble staircases and are identified by a slope σ that depends logarithmically on the specific energy \\varepsilon=E/N . Such solutions are found to lie on stable lower-dimensional tori, named q-tori. At higher energies there is a sharp transition of the system's localization profile to a straight-line one, determined by an N-dependent slope of the form σ ∼ (\\varepsilon N)-d , d > 0. We find that the energy crossover \\varepsilon c between the two energy regimes decays as 1/N , which indicates that q-tori disappear in the thermodynamic limit. Furthermore, we focus on the times that such localization profiles are practically frozen and we find that these “stickiness times” can rapidly and accurately distinguish between a power-law and a stretched exponential dependence in 1/\\varepsilon .

Tory II-A: a nuclear ramjet test reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hadley, J.W.

Declassified 28 Nov 1973. The first test reactor in the Pluto program, leading to development of a nuclear ramjet engine, is called Tory II-A. While it is not an actual prototype engine, this reactor embodies a core design which is considered feasible for an engine, and operation of the reactor will provide a test of that core type as well as more generalized values in reactor design and testing. The design of Tory II-A and construction of the reactor and of its test facility are described. Operation of the Tory II-A core at a total power of 160 megawatts, withmore » 800 pounds of air per second passing through the core and emerging at a temperature of 2000 deg F, is the central objective of the test program. All other reactor and facility components exist to support operation of the core, and preliminary steps in the test program itself will be directed primarily toward ensuring attalnment of full-power operation and collection of meaningful data on core behavior during that operation. The core, 3 feet in diameter and 41/2 feet long, will be composed of bundled ceramic tubes whose central holes will provide continuous air passages from end to end of the reactor. These tubes are to be composed of a homogeneous mixture of UO/sub 2/ fuel and BeO moderator, compacted and sintered to achieve high strength and density. (30 references) (auth)« less

Incorporating Historic Facility Geospatial Data and Federal Preservation Requirements into SDSFIE/FMSFIE

DTIC Science & Technology

2006-11-01

29 3.2.4 National Register Information System Model ............................................................... 30 3.3 Summary of...are later based on that information . Despite their general level of power and resolution, Federal data management and accounting tools have not yet...have begun tracking their historic building and structure inven- tories using geographic information systems (GISs). A geospatial-referenced data

Hypercat - Hypercube of AGN tori

NASA Astrophysics Data System (ADS)

Nikutta, Robert; Lopez-Rodriguez, Enrique; Ichikawa, Kohei; Levenson, Nancy A.; Packham, Christopher C.

2018-06-01

AGN unification and observations hold that a dusty torus obscures the central accretion engine along some lines of sight. SEDs of dust tori have been modeled for a long time, but resolved emission morphologies have not been studied in much detail, because resolved observations are only possible recently (VLTI,ALMA) and in the near future (TMT,ELT,GMT). Some observations challenge a simple torus model, because in several objects most of MIR emission appears to emanate from polar regions high above the equatorial plane, i.e. not where the dust supposedly resides.We introduce our software framework and hypercube of AGN tori (Hypercat) made with CLUMPY (www.clumpy.org), a large set of images (6 model parameters + wavelength) to facilitate studies of emission and dust morphologies. We make use of Hypercat to study the morphological properties of the emission and dust distributions as function of model parameters. We find that a simple clumpy torus can indeed produce 10-micron emission patterns extended in polar directions, with extension ratios compatible with those found in observations. We are able to constrain the range of parameters that produce such morphologies.

JPSS-1 Prelaunch News Conference

NASA Image and Video Library

2017-11-12

JPSS-1 Prelaunch News Conference at Vandenberg Air Force Base hosted by Tori Mclendon, with Steve Volz, NOAA Satellite and Information Service, Greg Mandt, Director, NOAA Joint Polar Satellite Systems Program, Sandra Smalley, NASA Joint Agency Satellite Division, Omar Baez, Launch Manager, NASA Launch Services Program, Scott Messer, Program Manager for NASA Missions, United Launch Alliance, and Ross Malugani, Launch Weather Officer, VAFB 30th Space Wing.

Drug-drug interactions between immunosuppressants and antidiabetic drugs in the treatment of post-transplant diabetes mellitus.

PubMed

Vanhove, Thomas; Remijsen, Quinten; Kuypers, Dirk; Gillard, Pieter

2017-04-01

Post-transplant diabetes mellitus is a frequent complication of solid organ transplantation that generally requires treatment with lifestyle interventions and antidiabetic medication. A number of demonstrated and potential pharmacokinetic drug-drug interactions (DDIs) exist between commonly used immunosuppressants and antidiabetic drugs, which are comprehensively summarized in this review. Cyclosporine (CsA) itself inhibits the cytochrome P450 (CYP) 3A4 enzyme and a variety of drug transporters. As a result, it increases exposure to repaglinide and sitagliptin, will likely increase the exposure to nateglinide, glyburide, saxagliptin, vildagliptin and alogliptin, and could theoretically increase the exposure to gliquidone and several sodium-glucose transporter (SGLT)-2 inhibitors. Currently available data, although limited, suggest that these increases are modest and, particularly with regard to gliptins and SGLT-2 inhibitors, unlikely to result in hypoglycemia. The interaction with repaglinide is more pronounced but does not preclude concomitant use if repaglinide dose is gradually titrated. Mycophenolate mofetil and azathioprine do not engage in DDIs with any antidiabetic drug. Although calcineurin inhibitors (CNIs) and mammalian target of rapamycin inhibitors (mTORi) are intrinsically prone to DDIs, their disposition is not influenced by metformin, pioglitazone, sulfonylureas (except possibly glyburide) or insulin. An effect of gliptins on the disposition of CNIs and mTORi is unlikely, but has not been definitively ruled out. Based on their disposition profiles, glyburide and canagliflozin could affect CNI and mTORi disposition although this requires further study. Finally, delayed gastric emptying as a result of glucagon-like peptide-1 agonists seems to have a limited, but not necessarily negligible effect on CNI disposition. Copyright © 2016 Elsevier Inc. All rights reserved.

General-relativistic rotation: Self-gravitating fluid tori in motion around black holes

NASA Astrophysics Data System (ADS)

Karkowski, Janusz; Kulczycki, Wojciech; Mach, Patryk; Malec, Edward; Odrzywołek, Andrzej; Piróg, Michał

2018-05-01

We obtain from the first principles a general-relativistic Keplerian rotation law for self-gravitating disks around spinning black holes. This is an extension of a former rotation law that was designed mainly for toroids around spinless black holes. We integrate numerically axial stationary Einstein equations with self-gravitating disks around spinless or spinning black holes; that includes the first ever integration of the Keplerian selfgravitating tori. This construction can be used for the description of tight black hole-torus systems produced during coalescences of two neutron stars or modelling of compact active galactic nuclei.

Grazing incidence toroidal mirror pairs in imaging and spectroscopic applications.

PubMed

Malvezzi, A M; Tondello, G

1983-08-15

The optical performance of pairs of toroidal mirrors in grazing incidence has been studied analytically and numerically. Two types of toroidal surface are possible: football and bicycle tire. In grazing incidence and for configurations that compensate up to second-order aberrations, there are significant differences in performance between the two types. For football-type tori the best configuration appears to be Z-shaped with tangential and sagittal foci at the middle point between the mirrors. For bicycle tire-type tori the best configuration is U-shaped with the tangential focus at the middle point and the sagittal at infinity.

GOES-S Prelaunch News Conference

NASA Image and Video Library

2018-02-27

In the Kennedy Space Center's Press Site auditorium, NASA and industry leaders speak to members of the media at a prelaunch news conference about National Oceanic and Atmospheric Administration's, or NOAA's, Geostationary Operational Environmental Satellite, or GOES-S. Participants from left are: Tori McLendon of NASA Communications; Stephen Volz, director for Satellite and Information Services for NOAA; Tim Walsh, acting GOES-R System Program director for NOAA; Sandra Smalley, director of the Joint Agency Satellite Division at NASA Headquarters in Washington D.C.; Tim Dunn, NASA launch director at Kennedy; Scott Messer, manager of NASA Programs for United launch Alliance; and Kathy Winters, launch weather officer for the U.S. Air Force 45th Weather Squadron at Cape Canaveral Air Force Station. The GOES series of satellites will significantly improve the detection and observation of environmental phenomena that directly affect public safety, protection of property and the nation's economic health and prosperity. GOES-S is slated to lift off at 5:02 p.m. EST on March 1, 2018 aboard a United Launch Alliance Atlas V rocket.

An Optical Fiber Communication System Based on Coherent Modulation. Part 1.

DTIC Science & Technology

1985-06-01

the’ local oscillator signal. In the receiver the two signals are recombined optically using a single mode fiber coupler or a beam splitter , and the...Fig. 2. Design of practical systems may imply the use of non - ideal laser diodes. In a cooperation with British Telecom Research Labora- tories we...frequency stabilisation *the transmission fiber - *injection locking of semiconductor lasers *the coherent receiver Our next target is complete design

The Linguistic Core Approach to StructuredTranslation and Analysis of Low Resource Languages

DTIC Science & Technology

2017-09-02

grammars from no training data and partial training data (as given by GFL). We are now anno - tating GFL for English, Portuguese, Chinese and...translation. In Proc. EMNLP, 2014. [20] F. Drewes, H.- J . Kreowski, and A. Habel. Hyperedge replacement graph grammars. Handbook of Graph Grammars, 1:95–162...tory, Jena, 2015. [41] B. Jones, J . Andreas, D. Bauer, K-M. Hermann, and K. Knight. Semantics- based machine translation with hyperedge replacement

Oral tori are associated with local mechanical and systemic factors: a case-control study.

PubMed

Morrison, Matthew Daniel; Tamimi, Faleh

2013-01-01

To estimate if various dental factors, medications, and medical conditions are associated with an increased risk for the presence of oral tori. Using a case-control study design, the investigators identified and adjudicated a sample of cases with torus palatinus (TP) and/or torus mandibularis (TM) during a 1.5-year period. The medical records were abstracted and data on dental factors, temporomandibular dysfunction (TMD), medications, and medical conditions were recorded. Risk estimates were calculated as adjusted odds ratios (AORs) with 95% confidence intervals (CIs) using conditional logistic regression analyses, and the P value was set at .05. The sample was composed of 66 subjects with TM, 34 subjects with TP, and 100 control subjects from the same database. Any form of oral torus (TP and/or TM) was associated significantly with TMD (AOR, 10.51; 95% CI, 4.46 to 24.78; P<.01) and tooth attrition (AOR, 5.22; 95% CI, 2.32 to 11.77; P<.01). TP was associated significantly with TMD (AOR, 4.14; 95% CI, 1.21 to 14.21; P<.05), tooth attrition (AOR, 38.18; 95% CI, 7.20 to 202.41; P<.01), and treated hypertension (AOR, 6.64; 95% CI, 1.31 to 33.57; P<.05). TM was associated significantly with TMD (AOR, 5.77; 95% CI, 2.38 to 13.98; P<.01), tooth attrition (AOR, 6.69; 95% CI, 2.78 to 16.14; P<.01), and a penicillin allergy (AOR, 4.45; 95% CI, 1.05 to 18.83; P<.05). This study provides clinical evidence showing significant associations between oral tori and various dental factors, medications, and medical conditions. These findings add to the list of environmental factors believed to contribute to the formation of oral tori. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

GRC-2011-C-00579

NASA Image and Video Library

2007-03-28

Photos for Web Feature by Victoria (Tori) Woods; Micro-Electro Mechanical Systems (MEMS) using vacuum technology; fabricating High Temperature Electronics for Harsh Environments using silicon carbide substrates

Joint Efforts Towards European HF Radar Integration

NASA Astrophysics Data System (ADS)

Rubio, A.; Mader, J.; Griffa, A.; Mantovani, C.; Corgnati, L.; Novellino, A.; Schulz-Stellenfleth, J.; Quentin, C.; Wyatt, L.; Ruiz, M. I.; Lorente, P.; Hartnett, M.; Gorringe, P.

2016-12-01

During the past two years, significant steps have been made in Europe for achieving the needed accessibility to High Frequency Radar (HFR) data for a pan-European use. Since 2015, EuroGOOS Ocean Observing Task Teams (TT), such as HFR TT, are operational networks of observing platforms. The main goal is on the harmonization of systems requirements, systems design, data quality, improvement and proof of the readiness and standardization of HFR data access and tools. Particular attention is being paid by HFR TT to converge from different projects and programs toward those common objectives. First, JERICO-NEXT (Joint European Research Infrastructure network for Coastal Observatory - Novel European eXpertise for coastal observaTories, H2020 2015 Programme) will contribute on describing the status of the European network, on seeking harmonization through exchange of best practices and standardization, on developing and giving access to quality control procedures and new products, and finally on demonstrating the use of such technology in the general scientific strategy focused by the Coastal Observatory. Then, EMODnet (European Marine Observation and Data Network) Physics started to assemble HF radar metadata and data products within Europe in a uniform way. This long term program is providing a combined array of services and functionalities to users for obtaining free of charge data, meta-data and data products on the physical conditions of European sea basins and oceans. Additionally, the Copernicus Marine Environment Monitoring Service (CMEMS) delivers from 2015 a core information service to any user related to 4 areas of benefits: Maritime Safety, Coastal and Marine Environment, Marine Resources, and Weather, Seasonal Forecasting and Climate activities. INCREASE (Innovation and Networking for the integration of Coastal Radars into EuropeAn marine SErvices - CMEMS Service Evolution 2016) will set the necessary developments towards the integration of existing European HFR operational systems into CMEMS. Finally, these current progresses will contribute to integrate HFR platforms as important operational components of EOOS, the European Ocean Observing System, designed to align and integrate Europe's ocean observing capacity for a truly integrated end-to-end ocean observing in Europe.

Tori and chaos in a simple C1-system

NASA Astrophysics Data System (ADS)

Roessler, O. E.; Kahiert, C.; Ughleke, B.

A piecewise-linear autonomous 3-variable ordinary differential equation is presented which permits analytical modeling of chaotic attractors. A once-differentiable system of equations is defined which consists of two linear half-systems which meet along a threshold plane. The trajectories described by each equation is thereby continuous along the divide, forming a one-parameter family of invariant tori. The addition of a damping term produces a system of equations for various chaotic attractors. Extension of the system by means of a 4-variable generalization yields hypertori and hyperchaos. It is noted that the hierarchy established is amenable to analysis by the use of Poincare half-maps. Applications of the systems of ordinary differential equations to modeling turbulent flows are discussed.

Invariant Tori in the Secular Motions of the Three-body Planetary Systems

NASA Astrophysics Data System (ADS)

Locatelli, Ugo; Giorgilli, Antonio

We consider the problem of the applicability of KAM theorem to a realistic problem of three bodies. In the framework of the averaged dynamics over the fast angles for the Sun-Jupiter-Saturn system we can prove the perpetual stability of the orbit. The proof is based on semi-numerical algorithms requiring both explicit algebraic manipulations of series and analytical estimates. The proof is made rigorous by using interval arithmetics in order to control the numerical errors.

Overcoming resistance to single-agent therapy for oncogenic BRAF gene fusions via combinatorial targeting of MAPK and PI3K/mTOR signaling pathways

PubMed Central

Jain, Payal; Silva, Amanda; Han, Harry J.; Lang, Shih-Shan; Zhu, Yuankun; Boucher, Katie; Smith, Tiffany E.; Vakil, Aesha; Diviney, Patrick; Choudhari, Namrata; Raman, Pichai; Busch, Christine M.; Delaney, Tim; Yang, Xiaodong; Olow, Aleksandra K.; Mueller, Sabine; Haas-Kogan, Daphne; Fox, Elizabeth; Storm, Phillip B.; Resnick, Adam C.; Waanders, Angela J.

2017-01-01

Pediatric low-grade gliomas (PLGGs) are frequently associated with activating BRAF gene fusions, such as KIAA1549-BRAF, that aberrantly drive the mitogen activated protein kinase (MAPK) pathway. Although RAF inhibitors (RAFi) have been proven effective in BRAF-V600E mutant tumors, we have previously shown how the KIAA1549-BRAF fusion can be paradoxically activated by RAFi. While newer classes of RAFi, such as PLX8394, have now been shown to inhibit MAPK activation by KIAA1549-BRAF, we sought to identify alternative MAPK pathway targeting strategies using clinically relevant MEK inhibitors (MEKi), along with potential escape mechanisms of acquired resistance to single-agent MAPK pathway therapies. We demonstrate effectiveness of multiple MEKi against diverse BRAF-fusions with novel N-terminal partners, with trametinib being the most potent. However, resistance to MEKi or PLX8394 develops via increased RTK expression causing activation of PI3K/mTOR pathway in BRAF-fusion expressing resistant clones. To circumvent acquired resistance, we show potency of combinatorial targeting with trametinib and everolimus, an mTOR inhibitor (mTORi) against multiple BRAF-fusions. While single-agent mTORi and MEKi PLGG clinical trials are underway, our study provides preclinical rationales for using MEKi and mTORi combinatorial therapy to stave off or prevent emergent drug-resistance in BRAF-fusion driven PLGGs. PMID:29156677

Tori sequences as remnants of multiple accreting periods of Kerr SMBHs

NASA Astrophysics Data System (ADS)

Pugliese, D.; Stuchlík, Z.

2018-03-01

Super-massive black holes (SMBHs) hosted in active galactic nuclei (AGNs) can be characterized by multi-accreting periods as the attractors interact with the environment during their life-time. These multi-accretion episodes should leave traces in the matter orbiting the attractor. Counterrotating and even misaligned structures orbiting around the SMBHs would be consequences of these episodes. Our task in this work is to consider situations where such accretions occur and to trace their remnants represented by several toroidal accreting fluids, corotating or counterrotating relative to the central Kerr attractor, and created in various regimes during the evolution of matter configurations around SMBHs. We focus particularly on the emergence of matter instabilities, i.e., tori collisions, accretion onto the central Kerr black hole, or creation of jet-like structures (proto-jets). Each orbiting configuration is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluid. We prove that sequences of configurations and hot points, where an instability occurs, characterize the Kerr SMBHs, depending mainly on their spin-mass ratios. The occurrence of tori accretion or collision are strongly constrained by the fluid rotation with respect to the central black hole and the relative rotation with respect to each other. Our investigation provides characteristic of attractors where traces of multi-accreting episodes can be found and observed.

On the co-existence of maximal and whiskered tori in the planetary three-body problem

NASA Astrophysics Data System (ADS)

Pinzari, Gabriella

2018-05-01

In this paper, we discuss about the possibility of the coexistence of stable and unstable quasi-periodic Kolmogorov-Arnold-Moser (kam) tori in a region of the phase space of the three-body problem. The argument of proof goes along kam theory and, especially, the production of two non-smoothly related systems of canonical coordinates in the same region of the phase space, the possibility of which is foreseen, for "properly degenerate" systems, by a theorem of Nekhoroshev and Miščenko and Fomenko. The two coordinate systems are alternative to the classical reduction of the nodes by Jacobi, described, e.g., in Arnold ["Small denominators and problems of stability of motion in classical and celestial mechanics," 18, 85-191 (1963)].

Heat asymptotics for nonminimal Laplace type operators and application to noncommutative tori

NASA Astrophysics Data System (ADS)

Iochum, B.; Masson, T.

2018-07-01

Let P be a Laplace type operator acting on a smooth hermitean vector bundle V of fiber CN over a compact Riemannian manifold given locally by P = - [gμν u(x) ∂μ∂ν +vν(x) ∂ν + w(x) ] where u ,vν , w are MN(C) -valued functions with u(x) positive and invertible. For any a ∈ Γ(End(V)) , we consider the asymptotics Tr(ae-tP) ∼ t↓0+ ∑r=0∞ ar(a , P) t (r - d) / 2 where the coefficients ar(a , P) can be written as an integral of the functions ar(a , P) (x) = tr [ a(x) Rr(x) ] . The computation of R2 is performed opening the opportunity to calculate the modular scalar curvature for noncommutative tori.

Twin peak high-frequency quasi-periodic oscillations as a spectral imprint of dual oscillation modes of accretion tori

NASA Astrophysics Data System (ADS)

Bakala, P.; Goluchová, K.; Török, G.; Šrámková, E.; Abramowicz, M. A.; Vincent, F. H.; Mazur, G. P.

2015-09-01

Context. High-frequency (millisecond) quasi-periodic oscillations (HF QPOs) are observed in the X-ray power-density spectra of several microquasars and low-mass X-ray binaries. Two distinct QPO peaks, so-called twin peak QPOs, are often detected simultaneously exhibiting their frequency ratio close or equal to 3:2. A widely discussed class of proposed QPOs models is based on oscillations of accretion toroidal structures orbiting in the close vicinity of black holes or neutron stars. Aims: Following the analytic theory and previous studies of observable spectral signatures, we aim to model the twin peak QPOs as a spectral imprint of specific dual oscillation regime defined by a combination of the lowest radial and vertical oscillation mode of slender tori. We consider the model of an optically thick slender accretion torus with constant specific angular momentum. We examined power spectra and fluorescent Kα iron line profiles for two different simulation setups with the mode frequency relations corresponding to the epicyclic resonance HF QPOs model and modified relativistic precession QPOs model. Methods: We used relativistic ray-tracing implemented in the parallel simulation code LSDplus. In the background of the Kerr spacetime geometry, we analyzed the influence of the distant observer inclination and the spin of the central compact object. Relativistic optical projection of the oscillating slender torus is illustrated by images in false colours related to the frequency shift. Results: We show that performed simulations yield power spectra with the pair of dominant peaks that correspond to the frequencies of radial and vertical oscillation modes and with the peak frequency ratio equal to the proper value 3:2 on a wide range of inclinations and spin values. We also discuss exceptional cases of a very low and very high inclination, as well as unstable high spin relativistic precession-like configurations that predict a constant frequency ratio equal to 1:2. We demonstrate a significant dependency of broadened Kα iron line profiles on the inclination of the distant observer. Conclusions: This study presents a further step towards the proper model of oscillating accretion tori producing HF QPOs. More realistic future simulations should be based on incorporating the resonant coupling of oscillation modes, the influence of torus opacity, and the pressure effects on the mode frequencies and the torus shape.

Strings on complex multiplication tori and rational conformal field theory with matrix level

NASA Astrophysics Data System (ADS)

Nassar, Ali

Conformal invariance in two dimensions is a powerful symmetry. Two-dimensional quantum field theories which enjoy conformal invariance, i.e., conformal field theories (CFTs) are of great interest in both physics and mathematics. CFTs describe the dynamics of the world sheet in string theory where conformal symmetry arises as a remnant of reparametrization invariance of the world-sheet coordinates. In statistical mechanics, CFTs describe the critical points of second order phase transitions. On the mathematics side, conformal symmetry gives rise to infinite dimensional chiral algebras like the Virasoro algebra or extensions thereof. This gave rise to the study of vertex operator algebras (VOAs) which is an interesting branch of mathematics. Rational conformal theories are a simple class of CFTs characterized by a finite number of representations of an underlying chiral algebra. The chiral algebra leads to a set of Ward identities which gives a complete non-perturbative solution of the RCFT. Identifying the chiral algebra of an RCFT is a very important step in solving it. Particularly interesting RCFTs are the ones which arise from the compactification of string theory as sigma-models on a target manifold M. At generic values of the geometric moduli of M, the corresponding CFT is not rational. Rationality can arise at particular values of the moduli of M. At these special values of the moduli, the chiral algebra is extended. This interplay between the geometric picture and the algebraic description encoded in the chiral algebra makes CFTs/RCFTs a perfect link between physics and mathematics. It is always useful to find a geometric interpretation of a chiral algebra in terms of a sigma-model on some target manifold M. Then the next step is to figure out the conditions on the geometric moduli of M which gives a RCFT. In this thesis, we limit ourselves to the simplest class of string compactifications, i.e., strings on tori. As Gukov and Vafa proved, rationality selects the complex-multiplication tori. On the other hand, the study of the matrix-level affine algebra Um,K is motivated by conformal field theory and the fractional quantum Hall effect. Gannon completed the classification of U m,K modular-invariant partition functions. Here we connect the algebra U2,K to strings on 2-tori describable by rational conformal field theories. We point out that the rational conformal field theories describing strings on complex-multiplication tori have characters and partition functions identical to those of the matrix-level algebra Um,K. This connection makes obvious that the rational theories are dense in the moduli space of strings on Tm, and may prove useful in other ways.

Hypercat - Hypercube of Clumpy AGN Tori

NASA Astrophysics Data System (ADS)

Nikutta, Robert; Lopez-Rodriguez, Enrique; Ichikawa, Kohei; Levenson, Nancy; Packham, Christopher C.

2017-06-01

Dusty tori surrounding the central engines of Active Galactic Nuclei (AGN) are required by the Unification Paradigm, and are supported by many observations, e.g. variable nuclear absorber (sometimes Compton-thick) in X-rays, reverberation mapping in optical/UV, hot dust emission and SED shapes in NIR/MIR, molecular and cool-dust tori observed with ALMA in sub-mm.While models of AGN torus SEDs have been developed and utilized for a long time, the study of the resolved emission morphology (brightness maps) has so far been under-appreciated, presumably because resolved observations of the central parsec in AGN are only possible very recently. Currently, only NIR+MIR interferometry is capable of resolving the nuclear dust emission (but not of producing images, until MATISSE comes online). Furthermore, MIR interferometry has delivered also puzzling results, e.g. that in some resolved sources the light emanates preferentially from polar directions above the "torus" system, and not from the equatorial plane, where most of the dust is located.We are preparing the release of a panchromatic, fully interpolable hypercube of brightness maps and projected dust images for a large number of CLUMPY torus models (Nenkova+2008), that will help facilitate studies of resolved AGN emission and dust morphologies. Together with the cube we will release a comprehensive set of open-source tools (Python) that will enable researches to work efficiently with this large hypercube:* easy sub-cube selection + memory-mapping (mitigating the too-big-for-RAM problem)* multi-dim image interpolation (get an image at any wavelength & model parameter combination)* simulation of observations with telescopes (compute/provide + apply a PSF) and interferometers (get visibilities)* analyze images with respect to the power contained at all scales and orientations (via 2D steerable wavelets), addressing the seemingly puzzling results mentioned aboveA series of papers is in preparation, aiming at solving the puzzles, and at making predictions about the resolvability of all nearby AGN tori with any combination of current and future instruments (e.g. VLTI+MATISSE, TMT+MICHI, GMT, ELT, JWST, ALMA).

Three-dimensional radiative transfer models of clumpy tori in Seyfert galaxies

NASA Astrophysics Data System (ADS)

Schartmann, M.; Meisenheimer, K.; Camenzind, M.; Wolf, S.; Tristram, K. R. W.; Henning, T.

2008-04-01

Context: Tori of Active Galactic Nuclei (AGN) are made up of a mixture of hot and cold gas, as well as dust. In order to protect the dust grains from destruction by the surrounding hot gas as well as by the energetic (UV/optical) radiation from the accretion disk, the dust is often assumed to be distributed in clouds. Aims: A new three-dimensional model of AGN dust tori is extensively investigated. The torus is modelled as a wedge-shaped disk within which dusty clouds are randomly distributed throughout the volume, by taking the dust density distribution of the corresponding continuous model into account. We especially concentrate on the differences between clumpy and continuous models in terms of the temperature distributions, the surface brightness distributions and interferometric visibilities, as well as spectral energy distributions. Methods: Radiative transfer calculations with the help of the three-dimensional Monte Carlo radiative transfer code MC3D are used in order to simulate spectral energy distributions as well as surface brightness distributions at various wavelengths. In a second step, interferometric visibilities for various inclination as well as position angles and baselines are calculated, which can be used to directly compare our models to interferometric observations with the MIDI instrument. Results: We find that the radial temperature distributions of clumpy models possess significantly enhanced scatter compared to the continuous cases. Even at large distances, clouds can be heated directly by the central accretion disk. The existence of the silicate 10 μm-feature in absorption or in emission depends sensitively on the distribution, the size and optical depth of clouds in the innermost part of the dust distribution. With this explanation, failure and success of previous modelling efforts of clumpy tori can be understood. The main reason for this outcome are shadowing effects of clouds within the central region. We underline this result with the help of several parameter variations. After adapting the parameters of our clumpy standard model to the circumstances of the Seyfert 2 Circinus galaxy, it can qualitatively explain recent mid-infrared interferometric observations performed with MIDI, as well as high resolution spectral data.

Friedreich's Ataxia (FA)

MedlinePlus

... success- ful people with FA — business leaders, outstanding students, engineers, active teens and bright kids, parents, even ... tory experiments have shown that it’s possible to design short fragments of DNA that prevent abnormal folding ...

Guidelines for Simulator-Based Marine Pilot Training Programs

DTIC Science & Technology

1985-03-01

Excellent’ Saifat Marginal Iiwartisfdc tory C oe n t s 0 / /0// .-ON I- FX- D OF V/L W L/wiT5. j :4 EX ER/? 15 r--5. 5Imu,1-tQ/0AJ OP- [319A/< E-.FPrc.r...REPOrT No. CG- D -25-85 CAORF-50-83 18-02 It) TECHNICAL REPORT GUIDELINES FOR SIMULATOR-BASED MARINE PILOT TRAINING PROGRAMS Reproduced From Best...constitute a standard, specification, or regulation. . Acoesson For - NTIS 7 &1 PTIC’ T,,R [_ 000, D.st r .. D !vr 4 i a -1 BIBLIOGRAPHIC DATA .Repof" No. 2. 3

Proceedings of the Annual Chemical Defense Bioscience Review (5th) Held at Columbia, Maryland on 29-31 May 1985. Appendix 1

DTIC Science & Technology

1985-06-01

and Meyer, H.G. Life Sciences 36: 1715-1720, 1985. 3. Van Helden, H.P.M.; van der Well, H.J.; and Wolthius, O.L. TNO Technical Report # MBL-1984-3...SYNTHESIS IN OUR LABORA- TORY BY STANDARD LITERATURE PROCEDURES OR AS A GIFT FROM PHARMA - CEUTICAL MANUFACTURERS THAT MARKET THE DRUGS, ALL OF THE COM- POUNDS...Rosenberry, T. L. Croatia Chemica Acto 1975, _7 235 Incursion of other steps then general base catalysis, such as confor-:ational changes, in rate

Magnitude and frequency of Iowa floods, Part two

USGS Publications Warehouse

Schwob, Harlan H.

1966-01-01

Floqd records fo.r regular and partial-record gaging stations are contained in the following pages. Each listing contains the station number .and name, descriptive paragraphs pertaining to the station, qnd a listing of the flood peaks available through the 1965 water year. Peaks above a base as well as annual peaks are listed. These provide the data for a partial-duration flood-frequency curve. Most of the material is self-explan~tory and needs no discussion. However, a few items may be made clearer by the brief explanation which follows. 

Metabolic Diseases of Muscle

MedlinePlus

... diets. Your MDA clinic director can help you design a specific plan suited for your metabolic disorder ... respira- tory or speech therapy consultations • annual flu shots • support groups for those affected, spouses, parents or ...

Duchenne and Becker Muscular Dystrophies

MedlinePlus

... trial in boys with the disease. In another approach, MDA-supported researchers at a biotechnology company are ... respira- tory or speech therapy consultations • annual flu shots • support groups for those affected, spouses, parents or ...

Berry phases for Landau Hamiltonians on deformed tori

NASA Astrophysics Data System (ADS)

Lévay, Péter

1995-06-01

Parametrized families of Landau Hamiltonians are introduced, where the parameter space is the Teichmüller space (topologically the complex upper half plane) corresponding to deformations of tori. The underlying SO(2,1) symmetry of the families enables an explicit calculation of the Berry phases picked up by the eigenstates when the torus is slowly deformed. It is also shown that apart from these phases that are local in origin, there are global non-Abelian ones too, related to the hidden discrete symmetry group Γϑ (the theta group, which is a subgroup of the modular group) of the families. The induced Riemannian structure on the parameter space is the usual Poincare metric on the upper half plane of constant negative curvature. Due to the discrete symmetry Γϑ the geodesic motion restricted to the fundamental domain of this group is chaotic.

Compact Binary Progenitors of Short Gamma-Ray Bursts

NASA Technical Reports Server (NTRS)

Giacomazzo, Bruno; Perna, Rosalba; Rezzolla, Luciano; Troja, Eleonora; Lazzati, Davide

2013-01-01

In recent years, detailed observations and accurate numerical simulations have provided support to the idea that mergers of compact binaries containing either two neutron stars (NSs) or an NS and a black hole (BH) may constitute the central engine of short gamma-ray bursts (SGRBs). The merger of such compact binaries is expected to lead to the production of a spinning BH surrounded by an accreting torus. Several mechanisms can extract energy from this system and power the SGRBs. Here we connect observations and numerical simulations of compact binary mergers, and use the current sample of SGRBs with measured energies to constrain the mass of their powering tori. By comparing the masses of the tori with the results of fully general-relativistic simulations, we are able to infer the properties of the binary progenitors that yield SGRBs. By assuming a constant efficiency in converting torus mass into jet energy epsilon(sub jet) = 10%, we find that most of the tori have masses smaller than 0.01 Solar M, favoring "high-mass" binary NSs mergers, i.e., binaries with total masses approx >1.5 the maximum mass of an isolated NS. This has important consequences for the gravitational wave signals that may be detected in association with SGRBs, since "high-mass" systems do not form a long-lived hypermassive NS after the merger. While NS-BH systems cannot be excluded to be the engine of at least some of the SGRBs, the BH would need to have an initial spin of approx. 0.9 or higher.

How to Spot a Primitive Black Hole

NASA Image and Video Library

2010-03-17

These two data plots from NASA Spitzer Space Telescope show a primitive supermassive black hole top compared to a typical one; usually, dust tori are missing and only gas disks are observed in primitive black holes.

Charcot-Marie-Tooth and Related Diseases

MedlinePlus

... acquired neu- ropathy, and thus might exacerbate CMT. Case studies have shown that the chemo- therapy drug vincristine ... respira- tory or speech therapy consultations • annual flu shots • support groups for those affected, spouses, parents or ...

A look at Bottomley's vision.

PubMed

The Conservatives have recently begun their fourth consecutive term of office. What are the implications for the NHS of a further 5 years of Tory rule and what difference, if any, will the new mistress of Richmond House make?

Numerical study of the geometry of the phase space of the Augmented Hill Three-Body problem

NASA Astrophysics Data System (ADS)

Farrés, Ariadna; Jorba, Àngel; Mondelo, Josep-Maria

2017-09-01

The Augmented Hill Three-Body problem is an extension of the classical Hill problem that, among other applications, has been used to model the motion of a solar sail around an asteroid. This model is a 3 degrees of freedom (3DoF) Hamiltonian system that depends on four parameters. This paper describes the bounded motions (periodic orbits and invariant tori) in an extended neighbourhood of some of the equilibrium points of the model. An interesting feature is the existence of equilibrium points with a 1:1 resonance, whose neighbourhood we also describe. The main tools used are the computation of periodic orbits (including their stability and bifurcations), the reduction of the Hamiltonian to centre manifolds at equilibria, and the numerical approximation of invariant tori. It is remarkable how the combination of these techniques allows the description of the dynamics of a 3DoF Hamiltonian system.

Hydrodynamic Studies of Turbulent AGN Tori

NASA Astrophysics Data System (ADS)

Schartmann, M.; Meisenheimer, K.; Klahr, H.; Camenzind, M.; Wolf, S.; Henning, Th.; Burkert, A.; Krause, M.

Recently, the MID-infrared Interferometric instrument (MIDI) at the VLTI has shown that dust tori in the two nearby Seyfert galaxies NGC 1068 and the Circinus galaxy are geometrically thick and can be well described by a thin, warm central disk, surrounded by a colder and fluffy torus component. By carrying out hydrodynamical simulations with the help of the TRAMP code (Klahr et al. 1999), we follow the evolution of a young nuclear star cluster in terms of discrete mass-loss and energy injection from stellar processes. This naturally leads to a filamentary large scale torus component, where cold gas is able to flow radially inwards. The filaments join into a dense and very turbulent disk structure. In a post-processing step, we calculate spectral energy distributions and images with the 3D radiative transfer code MC3D Wolf (2003) and compare them to observations. Turbulence in the dense disk component is investigated in a separate project.

Treatment, Outcome and Prognostic Factors in Renal Cell Carcinoma - A Single Center Study (2000-2010)

PubMed Central

Achermann, Christof; Stenner, Frank; Rothschild, Sacha I.

2016-01-01

In Switzerland efficient availability of novel drugs for renal cell cancer (RCC) has been granted early. Since the advent of the targeted agents for RCC the usage of these drugs has been reported to improve progression free survival. Here, we find that patients who are able to receive sequential targeted therapy, including tyrosine kinase inhibitors (TKI) and mTOR inhibitors (mTORi), have a largely better outcome than those who have less exposure to these agents. The value of the prognostic scores developed by Motzer and Heng is fully reflected by the outcomes according to prognostic risk groups in our unselected patient cohort. Also, the use of surgical intervention appears to be an important prognostic factor, however with a somehow diminished effect by novel systemic therapies. The importance of multiple lines of targeted therapies is underlined by this retrospective analysis. For patients with metastatic RCC not receiving targeted therapy the median OS was 22.6 months compared to those with one TKI 25.4 months. Patients receiving a second-line therapy (median overall survival 27.6 months) and those patients with three or more lines of therapy (43.8 months) have the greatest benefit. Also, exposure to a mTORi improves survival versus non-exposure to mTORi (63.3 vs. 22.3 months, p=0.038). In conclusion a trend towards improved survival is confirmed for an unselected population when the full variety of therapeutic options is available and can be used for the individual patient. PMID:27313782

Effects of Sheared Flow on Microinstabilities and Transport in Plasmas

NASA Astrophysics Data System (ADS)

H, Sanuki; K, Itoh; A, Fujisawa; J, Q. Dong

2005-02-01

Theoretical and experimental studies associated with electric field effects on the stability and transport are briefly surveyed. The effects of radial electric field on the suppression and/or enhancement of various microinstabilities such as drift waves, flute mode and temperature gradient modes are discussed. The suppression of flow shear on the electron temperature gradient mode in plasmas with slightly hollow density profiles is investigated by solving the gyrokinetic integral eigenvalue equation. Comparison between theoretical predictions and experimental observations based on the HIBP measurements with high temporal and spatial resolutions is made in bumpy tori and heliotron (CHS) devices.

Periodic orbits of the integrable swinging Atwood's machine

NASA Astrophysics Data System (ADS)

Nunes, Ana; Casasayas, Josefina; Tufillaro, Nicholas

1995-02-01

We identify all the periodic orbits of the integrable swinging Atwood's machine by calculating the rotation number of each orbit on its invariant tori in phase space, and also providing explicit formulas for the initial conditions needed to generate each orbit.

Place of mTOR inhibitors in management of BKV infection after kidney transplantation.

PubMed

Jouve, Thomas; Rostaing, Lionel; Malvezzi, Paolo

2016-01-01

BK virus (BKV) viremia and BKV-associated nephropathy (BKVAN) have become a serious nuisance to kidney transplant (KT) patients since the mid-nineties, when the incidence of this disease has increased significantly. Directory of open access journals (DOAJ), EMBASE, Google Scholar, PubMed, EBSCO, and Web of Science have been searched. Many hypothesis have been made as to why this phenomenon has developed; it is of general opinion that a more potent immunosuppression is at the core of the problem. The use of the association of tacrolimus (TAC) with mycophenolic acid (MPA) has gained momentum in the same years as the increase in BKV viremia incidence making it seem to be the most likely culprit. m-TOR inhibitors (m-TORIs) have been shown to have antiviral properties in vitro and this fact has encouraged different transplant teams to use these agents when confronted with BKV infection (viremia or nephropathy). However, the results are mitigated. There had been conflicting results for example when converting from TAC-to sirolimus-based immunosuppression in the setting of established BKVAN. In order to prevent BKV infection we have to minimize to some extent immunosuppression, but it is not always possible, e.g. in high immunological risk patients. Conversely, we could use m-TORIs associated with low-dose calcineurin inhibitors (CNIs). This could be actually the key to a safe immunosuppression regimen both from the immunological stand point and from the viral one.

OPTIMIZATION OF REPEATED BRONCHOALVEOLAR LAVAGE IN RABBITS

EPA Science Inventory

Background. Bronchoalveolar lavage (BAL) is a relatively non-invasive technique used to obtain diagnostic samples from the lower airways of companion animals with respira¬tory disease. BAL is also commonly used in laboratory animals to assess pulmo¬nary changes after expos...

Proto-jet configurations in RADs orbiting a Kerr SMBH: symmetries and limiting surfaces

NASA Astrophysics Data System (ADS)

Pugliese, D.; Stuchlík, Z.

2018-05-01

Ringed accretion disks (RADs) are agglomerations of perfect-fluid tori orbiting around a single central attractor that could arise during complex matter inflows in active galactic nuclei. We focus our analysis to axi-symmetric accretion tori orbiting in the equatorial plane of a supermassive Kerr black hole; equilibrium configurations, possible instabilities, and evolutionary sequences of RADs were discussed in our previous works. In the present work we discuss special instabilities related to open equipotential surfaces governing the material funnels emerging at various regions of the RADs, being located between two or more individual toroidal configurations of the agglomerate. These open structures could be associated to proto-jets. Boundary limiting surfaces are highlighted, connecting the emergency of the jet-like instabilities with the black hole dimensionless spin. These instabilities are observationally significant for active galactic nuclei, being related to outflows of matter in jets emerging from more than one torus of RADs orbiting around supermassive black holes.

Antiholomorphic perturbations of Weierstrass Zeta functions and Green’s function on tori

NASA Astrophysics Data System (ADS)

Bogdanov, Konstantin; Mamayusupov, Khudoyor; Mukherjee, Sabyasachi; Schleicher, Dierk

2017-08-01

In Bergweiler and Eremenko (2016 Proc. Am. Math. Soc. 144 2911-22), Bergweiler and Eremenko computed the number of critical points of the Green’s function on a torus by investigating the dynamics of a certain family of antiholomorphic meromorphic functions on tori. They also observed that hyperbolic maps are dense in this family of meromorphic functions in a rather trivial way. In this paper, we study the parameter space of this family of meromorphic functions, which can be written as antiholomorphic perturbations of Weierstrass Zeta functions. On the one hand, we give a complete topological description of the hyperbolic components and their boundaries, and on the other hand, we show that these sets admit natural parametrizations by associated dynamical invariants. This settles a conjecture, made in Lin and Wang (2010 Ann. Math. 172 911-54), on the topology of the regions in the upper half plane {H} where the number of critical points of the Green’s function remains constant.

Eigenvalue problems for Beltrami fields arising in a three-dimensional toroidal magnetohydrodynamic equilibrium problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hudson, S. R.; Hole, M. J.; Dewar, R. L.

2007-05-15

A generalized energy principle for finite-pressure, toroidal magnetohydrodynamic (MHD) equilibria in general three-dimensional configurations is proposed. The full set of ideal-MHD constraints is applied only on a discrete set of toroidal magnetic surfaces (invariant tori), which act as barriers against leakage of magnetic flux, helicity, and pressure through chaotic field-line transport. It is argued that a necessary condition for such invariant tori to exist is that they have fixed, irrational rotational transforms. In the toroidal domains bounded by these surfaces, full Taylor relaxation is assumed, thus leading to Beltrami fields {nabla}xB={lambda}B, where {lambda} is constant within each domain. Two distinctmore » eigenvalue problems for {lambda} arise in this formulation, depending on whether fluxes and helicity are fixed, or boundary rotational transforms. These are studied in cylindrical geometry and in a three-dimensional toroidal region of annular cross section. In the latter case, an application of a residue criterion is used to determine the threshold for connected chaos.« less

Breakup of Kol'mogorov-Arnol'd-Moser tori of cubic irrational winding number

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mao, J.; Helleman, R.H.G.

1989-01-01

For the special case in which the irrational winding number is the root of a cubic equation, we present numerical evidence for the validity of some form of residue criterion (Greene, J. Math. Phys. 20, 1182 (1979)). This is a criterion for the breakup of Kol'mogorov-Arnol'd-Moser tori in two degrees of freedom. The cubic case is essential for future work on four-dimensional maps. While the residues do approach infinity (respectively, 0) after (respectively, before) the breaking point, it is numerically very difficult to estimate a critical residue value R/sub cr/ for this cubic case (0.15approx. ..infinity, with a ''new'' scalingmore » constant xiapprox. =0.72, where p/sub n//q/sub n/ is the nth rational approximant in the continued-fraction expansion of the cubic irrational. For a quadratic irrational this scaling reduces to the usual power-law scaling approx.delta/sup -//sup n/.« less

Studies of the Gas Tori of Titan and Triton

NASA Technical Reports Server (NTRS)

Smyth, William H.; Marconi, M. L.

1997-01-01

A model for the spatial distribution of hydrogen in the Saturn system including a Titan source, an interior source for the rings and inner icy satellites, and a Saturn source has been applied to the best available Voyager 1 and 2 UVS Lyman-alpha observations presented by Shemansky and Hall. Although the model-data comparison is limited by the quality of the observational data, source rates for a Titan source of 3.3 - 4.8 x 10(exp 27) H atoms/s and, for the first time, source rates larger by about a factor of four for the interior source of 1.4 - 1.9 x 10(exp 27) H atoms/s were determined. Outside the immediate location of the planet, the Saturn source is only a minor contribution of hydrogen. A paper describing this research in more detail has been submitted to The Astrophysical Journal for publication and is included in the Appendix. Limited progress in the development of a model for the collisional gas tori of Triton is also discussed.

Solving the incompressible surface Navier-Stokes equation by surface finite elements

NASA Astrophysics Data System (ADS)

Reuther, Sebastian; Voigt, Axel

2018-01-01

We consider a numerical approach for the incompressible surface Navier-Stokes equation on surfaces with arbitrary genus g (S ) . The approach is based on a reformulation of the equation in Cartesian coordinates of the embedding R3, penalization of the normal component, a Chorin projection method, and discretization in space by surface finite elements for each component. The approach thus requires only standard ingredients which most finite element implementations can offer. We compare computational results with discrete exterior calculus simulations on a torus and demonstrate the interplay of the flow field with the topology by showing realizations of the Poincaré-Hopf theorem on n-tori.

A tutorial on dynamical systems concepts applied to Lagrangian transport in oceanic flows defined as finite time data sets: Theoretical and computational issues

NASA Astrophysics Data System (ADS)

Mancho, Ana M.; Small, Des; Wiggins, Stephen

2006-12-01

In the past 15 years the framework and ideas from dynamical systems theory have been applied to a variety of transport and mixing problems in oceanic flows. The motivation for this approach comes directly from advances in observational capabilities in oceanography (e.g., drifter deployments, remote sensing capabilities, satellite imagery, etc.) which reveal space-time structures that are highly suggestive of the structures one visualizes in the global, geometrical study of dynamical systems theory. In this tutorial, we motivate this approach by showing the relationship between fluid transport in two-dimensional time-periodic incompressible flows and the geometrical structures that exist for two-dimensional area-preserving maps, such as hyperbolic periodic orbits, their stable and unstable manifolds and KAM (Kolmogorov-Arnold-Moser) tori. This serves to set the stage for the attempt to “transfer” this approach to more realistic flows modelling the ocean. However, in order to accomplish this several difficulties must be overcome. The first difficulty that confronts us that any attempt to carry out a dynamical systems approach to transport requires us to obtain the appropriate “dynamical system”, which is the velocity field describing the fluid flow. In general, adequate model velocity fields are obtained by numerical solution of appropriate partial differential equations describing the dynamical evolution of the velocity field. Numerical solution of the partial differential equations can only be done for a finite time interval, and since the ocean is generally not time-periodic, this leads to a new type of dynamical system: a finite-time, aperiodically time-dependent velocity field defined as a data set on a space-time grid. The global, geometrical analysis of transport in such dynamical systems requires both new concepts and new analytical and computational tools, as well as the necessity to discard some of the standard ideas and results from dynamical systems theory. The purpose of this tutorial is to describe these new concepts and analytical tools first using simple dynamical systems where quantities can be computed exactly. We then discuss their computational implications and implementation in the context of a model geophysical flow: a turbulent wind-driven double-gyre in the quasigeostrophic approximation.

A Female Interrogative Reader: The Adolescent Jane Austen Reads and Rewrites (His)tory.

ERIC Educational Resources Information Center

Reid-Walsh, Jacqueline

1992-01-01

Argues that Jane Austen's unpublished juvenile work "The History of England" has considerable relevance to twentieth-century high-school English classrooms. Notes that the work humorously shows the gender bias of traditional history texts because it is a "woman-centered" rewriting. (RS)

How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stavrakou, T.; Muller, J. F.; Bauwens, M.

2015-10-26

The vertical columns of formaldehyde (HCHO) retrieved from two satellite instruments, the Global Ozone Monitoring Instrument-2 (GOME-2) on Metop-A and the Ozone Monitoring Instrument (OMI) on Aura, are used to constrain global emissions of HCHO precursors from open fires, vegetation and human activities in the year 2010. To this end, the emissions are varied and optimized using the ad-joint model technique in the IMAGESv2 global CTM (chem-ical transport model) on a monthly basis and at the model res-olution. Given the different local overpass times of GOME- 2 (09:30 LT) and OMI (13:30 LT), the simulated diurnal cy-cle of HCHO columnsmore » is investigated and evaluated against ground-based optical measurements at seven sites in Europe, China and Africa. The modeled diurnal cycle exhibits large variability, reflecting competition between photochemistry and emission variations, with noon or early afternoon max-ima at remote locations (oceans) and in regions dominated by anthropogenic emissions, late afternoon or evening max-ima over fire scenes, and midday minima in isoprene-rich re-gions. The agreement between simulated and ground-based columns is generally better in summer (with a clear after-noon maximum at mid-latitude sites) than in winter, and the annually averaged ratio of afternoon to morning columns is slightly higher in the model (1.126) than in the ground-based measurements (1.043).The anthropogenic VOC (volatile organic compound) sources are found to be weakly constrained by the inversions on the global scale, mainly owing to their generally minor contribution to the HCHO columns, except over strongly pol-luted regions, like China. The OMI-based inversion yields total flux estimates over China close to the bottom-up inven-tory (24.6 vs. 25.5 TgVOC yr -1 in the a priori) with, how-ever, pronounced increases in the northeast of China and re-ductions in the south. Lower fluxes are estimated based on GOME-2 HCHO columns (20.6 TgVOC yr -1), in particular over the northeast, likely reflecting mismatches between the observed and the modeled diurnal cycle in this region.« less

Get Your Bearings

ERIC Educational Resources Information Center

Teaching Pre K-8, 2004

2004-01-01

This article describes an outdoor activity known as orienteering, the practice of using a map and a compass to find points in a landscape. Downloadable materials, courtesy of The Roger Tory Peterson Institute, can be found on www.TeachingK-8.com. These materials include instructions for the activity and reproducible illustrations of seven basic…

Estrogen Receptor Mutants/Variants in Human Breast Cancer.

DTIC Science & Technology

1997-12-01

a recipient of a USAMRMC Postdoctoral Fellowship Award. The authors thank Caroline Cumins -Leygue and Helen Bergen for labora- tory assistance with...of their ER status as determined by ligand binding assay. It should be stressed that an additional band can be observed in most of the samples. This

Relating Expected Inventory Backorders to Safety Stock Investment Levels.

DTIC Science & Technology

1981-09-01

Theory," RM-4185-PR. The Rand Corporation, Santa Monica CA, September 1964. 105 11. Haeussler, Ernest F. Jr., and Richard S. Paul. Introduc- tory...14. Lewis, Colin D. Demand Analysis and Inventor4 Control. Westmead, England: Saxon House D.C. Heath Ltd., 1975. 15. Lippert , Keith Wayne. "An

An evaluation of known remaining oil resources in the United States: Appendix. Volume 10

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Volume ten contains the following appendices: overview of improved oil recovery methods which covers enhanced oil recovery methods and advanced secondary recovery methods; the benefits of improved oil recovery, selected data for the analyzed states; and list of TORIS fields and reservoirs.

Quality Assurance Specifications for Planetary Protection Assays

NASA Astrophysics Data System (ADS)

Baker, Amy

As the European Space Agency planetary protection (PP) activities move forward to support the ExoMars and other planetary missions, it will become necessary to increase staffing of labo-ratories that provide analyses for these programs. Standardization of procedures, a comprehen-sive quality assurance program, and unilateral training of personnel will be necessary to ensure that the planetary protection goals and schedules are met. The PP Quality Assurance/Quality Control (QAQC) program is designed to regulate and monitor procedures performed by labora-tory personnel to ensure that all work meets data quality objectives through the assembly and launch process. Because personnel time is at a premium and sampling schedules are often de-pendent on engineering schedules, it is necessary to have flexible staffing to support all sampling requirements. The most productive approach to having a competent and flexible work force is to establish well defined laboratory procedures and training programs that clearly address the needs of the program and the work force. The quality assurance specification for planetary protection assays has to ensure that labora-tories and associated personnel can demonstrate the competence to perform assays according to the applicable standard AD4. Detailed subjects included in the presentation are as follows: • field and laboratory control criteria • data reporting • personnel training requirements and certification • laboratory audit criteria. Based upon RD2 for primary and secondary validation and RD3 for data quality objectives, the QAQC will provide traceable quality assurance safeguards by providing structured laboratory requirements for guidelines and oversight including training and technical updates, standardized documentation, standardized QA/QC checks, data review and data archiving.

General Relativistic Magnetohydrodynamics Simulations of Tilted Black Hole Accretion Flows and Their Radiative Properties

NASA Astrophysics Data System (ADS)

Shiokawa, Hotaka; Gammie, C. F.; Dolence, J.; Noble, S. C.

2013-01-01

We perform global General Relativistic Magnetohydrodynamics (GRMHD) simulations of non-radiative, magnetized disks that are initially tilted with respect to the black hole's spin axis. We run the simulations with different size and tilt angle of the tori for 2 different resolutions. We also perform radiative transfer using Monte Carlo based code that includes synchrotron emission, absorption and Compton scattering to obtain spectral energy distribution and light curves. Similar work was done by Fragile et al. (2007) and Dexter & Fragile (2012) to model the super massive black hole SgrA* with tilted accretion disks. We compare our results of fully conservative hydrodynamic code and spectra that include X-ray, with their results.

Analysis of the Federal Cataloging System and COSATI (Committee on Scientific and Technical Information) Cataloging,

DTIC Science & Technology

1985-06-21

etc. Animal anatomy, physiology, and pathology. Care and breeding of labora- tory animals. For human anatomy and physiology, see 06 16 Physiology...sensation, etc. Human anatomy . For animal anatomy and physiology, see 06 03 Biology. For physiological psychology, see 05 10 Psychology. See also 06 19

Pit membranes of Ephedra resemble gymnosperms more than angiosperms

Treesearch

Roland Dute; Lauren Bowen; Sarah Schier; Alexa Vevon; Troy Best; Maria Auad; Thomas Elder; Pauline Bouche; Steven Jansen

2014-01-01

Bordered pit pairs of Ephedra species were characterized using different types of microscopy. Pit membranes contained tori that did not stain for lignin. SEM and AFM views of the torus surface showed no plasmodesmatal openings, but branched, secondary plasmodesmata were occasionally noted using TEM in conjunction with ultrathin sections. The margo consisted of radial...

Detection of Radiofrequency Radiation - Induced Whole Body Heating Following Chemical Impairment of Thermoregulation

DTIC Science & Technology

1981-10-01

insulation during shivering in the rat, which nas a large body surface area to mass ratio (Bligh, 1973). Ambient temperature plays a critical role in this...S.M. (1979). Microwaves: Effects on thermoregula- tory behavior in rats. Science 206:1198. Szekely, M. and Szelenyi, Z. (1979). Endotoxin fever in

Limits to the Extraction of Information from Multi-Hop Skywave Radar Signals

DTIC Science & Technology

2005-04-14

equations to compute the eikonal rays gh a model ionosphere, plotting the resulting tories in the range-height plane. oes received via these multi...kilometres. This extensive database is ideally suited to the sta- tistical analysis of the directional, diurnal, seasonal 0 0 500 1000 1500 2000 2500

An evaluation of known remaining oil resources in the United States. Appendix, Project on Advanced Oil Recovery and the States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This volume contains appendices for the following: Overview of improved oil recovery methods (enhanced oil recovery methods and advanced secondary recovery methods); Benefits of improved oil recovery, selected data for the analyzed states; and List of TORIS fields and reservoirs.

Paired quantum Hall states on noncommutative two-tori

NASA Astrophysics Data System (ADS)

Marotta, Vincenzo; Naddeo, Adele

2010-08-01

By exploiting the notion of Morita equivalence for field theories on noncommutative tori and choosing rational values of the noncommutativity parameter θ (in appropriate units), a one-to-one correspondence between an Abelian noncommutative field theory (NCFT) and a non-Abelian theory of twisted fields on ordinary space can be established. Starting from this general result, we focus on the conformal field theory (CFT) describing a quantum Hall fluid (QHF) at paired states fillings ν=mp/m+2 Cristofano et al. (2000) [1], recently obtained by means of m-reduction procedure, and show that it is the Morita equivalent of a NCFT. In this way we extend the construction proposed in Marotta and Naddeo (2008) [2] for the Jain series ν=>m2p/m+1. The case m=2 is explicitly discussed and the role of noncommutativity in the physics of quantum Hall bilayers is emphasized. Our results represent a step forward the construction of a new effective low energy description of certain condensed matter phenomena and help to clarify the relationship between noncommutativity and quantum Hall fluids.

Whole Device Modeling of Compact Tori: Stability and Transport Modeling of C-2W

NASA Astrophysics Data System (ADS)

Dettrick, Sean; Fulton, Daniel; Lau, Calvin; Lin, Zhihong; Ceccherini, Francesco; Galeotti, Laura; Gupta, Sangeeta; Onofri, Marco; Tajima, Toshiki; TAE Team

2017-10-01

Recent experimental evidence from the C-2U FRC experiment shows that the confinement of energy improves with inverse collisionality, similar to other high beta toroidal devices, NSTX and MAST. This motivated the construction of a new FRC experiment, C-2W, to study the energy confinement scaling at higher electron temperature. Tri Alpha Energy is working towards catalysing a community-wide collaboration to develop a Whole Device Model (WDM) of Compact Tori. One application of the WDM is the study of stability and transport properties of C-2W using two particle-in-cell codes, ANC and FPIC. These codes can be used to find new stable operating points, and to make predictions of the turbulent transport at those points. They will be used in collaboration with the C-2W experimental program to validate the codes against C-2W, mitigate experimental risk inherent in the exploration of new parameter regimes, accelerate the optimization of experimental operating scenarios, and to find operating points for future FRC reactor designs.

Generation of multiple toroidal dust vortices by a non-monotonic density gradient in a direct current glow discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaur, Manjit, E-mail: manjit@ipr.res.in; Bose, Sayak; Chattopadhyay, P. K.

2015-09-15

Observation of two well-separated dust vortices in an unmagnetized parallel plate DC glow discharge plasma is reported in this paper. A non-monotonic radial density profile, achieved by an especially designed cathode structure using a concentric metallic disk and ring of different radii, is observed to produce double dust tori between cathode and anode. PIV analysis of the still images of the double tori shows oppositely rotating dust structures between the central disk and the ring. Langmuir probe measurements of background plasma shows a non-uniform plasma density profile between the disk and the ring. Location and sense of rotation of themore » dust vortices coincides with the location and direction of the radial gradient in the ion drag force caused by the radial density gradient. The experimentally observed dust vorticity matches well with the calculated one using hydrodynamic formulations with shear in ion drag dominating over the dust charge gradient. These results corroborate that a radial gradient in the ion drag force directed towards cathode is the principal cause of dust rotation.« less

Spectral Structure of Temperature Variations in the Midlatitude Mesopause Region

NASA Astrophysics Data System (ADS)

Perminov, V. I.; Semenov, A. I.; Medvedeva, I. V.; Pertsev, N. N.; Sukhodoev, V. A.

2018-01-01

Long-term series of midnight temperature in the mesopause region have been obtained from spectral observations of hydroxyl airglow emission (OH(6-2) λ840 nm band) at the Tory station (52° N, 103° E) in 2008-2016 and Zvenigorod (56° N, 37° E) station in 2000-2016. On their basis, the Lomb-Scargle spectra of the variations in the period range from 12 days to 11 years have been determined. Estimates of the amplitudes of statistically significant temperature fluctuations are made. The dominant oscillations are the first and second harmonics of the annual variation, the amplitudes of which are 23-24 K and 4-7 K, respectively. The remaining variations, the number of which was 16 for the Tory and 22 for Zvenigorod stations, have small amplitudes (0.5-3 K). Oscillations with combinational frequencies, which arise from modulation of the annual variation harmonics, are observed in a structure of the variation spectra in addition to interannual oscillations (periods from 2 to 11 years) and harmonics of the annual variation (up to its tenth harmonic).

Turbulent AGN tori .

NASA Astrophysics Data System (ADS)

Schartmann, M.; Meisenheimer, K.; Klahr, H.; Camenzind, M.; Wolf, S.; Henning, Th.

Recently, the MID-infrared Interferometric instrument (MIDI) at the VLTI has shown that dust tori in the two nearby Seyfert galaxies NGC 1068 and the Circinus galaxy are geometrically thick and can be well described by a thin, warm central disk, surrounded by a colder and fluffy torus component. By carrying out hydrodynamical simulations with the help of the TRAMP code \\citep{schartmann_Klahr_99}, we follow the evolution of a young nuclear star cluster in terms of discrete mass-loss and energy injection from stellar processes. This naturally leads to a filamentary large scale torus component, where cold gas is able to flow radially inwards. The filaments open out into a dense and very turbulent disk structure. In a post-processing step, we calculate observable quantities like spectral energy distributions or images with the help of the 3D radiative transfer code MC3D \\citep{schartmann_Wolf_03}. Good agreement is found in comparisons with data due to the existence of almost dust-free lines of sight through the large scale component and the large column densities caused by the dense disk.

Chaotic interactions of self-replicating RNA.

PubMed

Forst, C V

1996-03-01

A general system of high-order differential equations describing complex dynamics of replicating biomolecules is given. Symmetry relations and coordinate transformations of general replication systems leading to topologically equivalent systems are derived. Three chaotic attractors observed in Lotka-Volterra equations of dimension n = 3 are shown to represent three cross-sections of one and the same chaotic regime. Also a fractal torus in a generalized three-dimensional Lotka-Volterra Model has been linked to one of the chaotic attractors. The strange attractors are studied in the equivalent four-dimensional catalytic replicator network. The fractal torus has been examined in adapted Lotka-Volterra equations. Analytic expressions are derived for the Lyapunov exponents of the flow in the replicator system. Lyapunov spectra for different pathways into chaos has been calculated. In the generalized Lotka-Volterra system a second inner rest point--coexisting with (quasi)-periodic orbits--can be observed; with an abundance of different bifurcations. Pathways from chaotic tori, via quasi-periodic tori, via limit cycles, via multi-periodic orbits--emerging out of periodic doubling bifurcations--to "simple" chaotic attractors can be found.

Issues in measure-preserving three dimensional flow integrators: Self-adjointness, reversibility, and non-uniform time stepping

DOE PAGES

Finn, John M.

2015-03-01

Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a 'special divergence-free' property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. Wemore » also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Ref. [11], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Ref. [35], appears to work very well.« less

(Re)presenting Equestrian "His"tories--Storytelling as a Method of Inquiry

ERIC Educational Resources Information Center

Linghede, Eva; Larsson, Håkan; Redelius, Karin

2016-01-01

Responding to calls about the need to "give voice" to groups previously marginalized in research and to challenge meta-narratives about men in sports, this paper explores the use of a narrative approach to illuminate men's experiences--and the doing of gender--within equestrian sports, a sport dominated by women in Sweden. Adopting the…

Atomic force microscopy of torus-bearing pit membranes

Treesearch

Roland R. Dute; Thomas Elder

2011-01-01

Atomic force microscopy was used to compare the structures of dried, torus-bearing pit membranes from four woody species, three angiosperms and one gymnosperm. Tori of Osmanthus armatus are bipartite consisting of a pustular zone overlying parallel sets of microfibrils that form a peripheral corona. Microfibrils of the corona form radial spokes as they traverse the...

Rescuing Teacher Professionalism

ERIC Educational Resources Information Center

Gillard, Derek

2005-01-01

If teachers are to reclaim any sort of agenda--let alone a radical one--they need to be taken seriously as professionals. Why aren't they? Derek Gillard surveys the history of teaching in England and argues that teacher professionalism was a short-lived phenomenon which has been in decline for thirty years. Far from rescuing it from the Tories,…

Complications of hyperglycaemia with PI3K–AKT–mTOR inhibitors in patients with advanced solid tumours on Phase I clinical trials

PubMed Central

Geuna, E; Roda, D; Rafii, S; Jimenez, B; Capelan, M; Rihawi, K; Montemurro, F; Yap, T A; Kaye, S B; De Bono, J S; Molife, L R; Banerji, U

2015-01-01

Background: PI3K–AKT–mTOR inhibitors (PAMi) are promising anticancer treatments. Hyperglycaemia is a mechanism-based toxicity of these agents and is becoming increasingly important with their use in larger numbers of patients. Methods: Retrospective case-control study comparing incidence and severity of hyperglycaemia (all grades) between a case group of 387 patients treated on 18 phase I clinical trials with PAMi (78 patients with PI3Ki, 138 with mTORi, 144 with AKTi and 27 with PI3K/mTORi) and a control group of 109 patients treated on 10 phase I clinical trials with agents not directly targeting the PAM pathway. Diabetic patients were excluded in both groups. Results: The incidence of hyperglycaemia was not significantly different between cases and controls (86.6% vs 80.7%, respectively, P=0.129). However, high grade (grade 3–4) hyperglycaemia was more frequent in the PAMi group than in controls (6.7% vs 0%, respectively, P=0.005). The incidence of grade 3–4 hyperglycaemia was greater with AKT and multikinase inhibitors compared with other PAMi (P<0.001). All patients with high-grade hyperglycaemia received antihyperglycemic treatment and none developed severe metabolic complications (diabetic ketoacidosis or hyperosmolar hyperglycemic nonketotic state). High-grade hyperglycaemia was the cause of permanent PAMi discontinuation in nine patients. Conclusions: PI3K–AKT–mTOR inhibitors are associated with small (6.7%) but statistically significant increased risk of high-grade hyperglycaemia compared with non-PAM targeting agents. However, PAMi-induced hyperglycaemia was not found to be associated with severe metabolic complications in this non-diabetic population of patients with advanced cancers. PMID:26554652

Complications of hyperglycaemia with PI3K-AKT-mTOR inhibitors in patients with advanced solid tumours on Phase I clinical trials.

PubMed

Geuna, E; Roda, D; Rafii, S; Jimenez, B; Capelan, M; Rihawi, K; Montemurro, F; Yap, T A; Kaye, S B; De Bono, J S; Molife, L R; Banerji, U

2015-12-01

PI3K-AKT-mTOR inhibitors (PAMi) are promising anticancer treatments. Hyperglycaemia is a mechanism-based toxicity of these agents and is becoming increasingly important with their use in larger numbers of patients. Retrospective case-control study comparing incidence and severity of hyperglycaemia (all grades) between a case group of 387 patients treated on 18 phase I clinical trials with PAMi (78 patients with PI3Ki, 138 with mTORi, 144 with AKTi and 27 with PI3K/mTORi) and a control group of 109 patients treated on 10 phase I clinical trials with agents not directly targeting the PAM pathway. Diabetic patients were excluded in both groups. The incidence of hyperglycaemia was not significantly different between cases and controls (86.6% vs 80.7%, respectively, P=0.129). However, high grade (grade 3-4) hyperglycaemia was more frequent in the PAMi group than in controls (6.7% vs 0%, respectively, P=0.005). The incidence of grade 3-4 hyperglycaemia was greater with AKT and multikinase inhibitors compared with other PAMi (P<0.001). All patients with high-grade hyperglycaemia received antihyperglycemic treatment and none developed severe metabolic complications (diabetic ketoacidosis or hyperosmolar hyperglycemic nonketotic state). High-grade hyperglycaemia was the cause of permanent PAMi discontinuation in nine patients. PI3K-AKT-mTOR inhibitors are associated with small (6.7%) but statistically significant increased risk of high-grade hyperglycaemia compared with non-PAM targeting agents. However, PAMi-induced hyperglycaemia was not found to be associated with severe metabolic complications in this non-diabetic population of patients with advanced cancers.

Interaction of Jovian energetic particles with moons and gas tori based on recent Juno/JEDI data

NASA Astrophysics Data System (ADS)

Kollmann, P.; Mauk, B.; Clark, G. B.; Paranicas, C.; Haggerty, D. K.; Rymer, A. M.; Bolton, S. J.; Connerney, J. E. P.; Levin, S.

2016-12-01

Juno is the first spacecraft in a polar orbit around Jupiter. It entered orbit in July 2016, will deliver the first science data from near Jupiter at the end of August, and pass very close to Jupiter 4 more times by December. We will use data from the three JEDI instruments onboard that measure ions and electrons in the tens of keV to MeV range while discriminating among ion species. Recording of the full energy and time-of-flight information of a subset of the detected particles will allow distinguishing foreground from contaminating background in many cases. Since Juno will be mostly at high latitudes, the JEDI measurements will differ from the measurements of previous missions that were mostly in the equatorial plane. The increasingly strong radiation environment inwards of Europa's orbit caused contamination and/or dead time effects in many of the previously flown particle instruments, which made it difficult to study this region with the existing data. We expect that Juno's unique orbit and the JEDI design will largely avoid these problems. During one hour of closest approach, Juno will be on magnetic field lines that map within the orbits of the Galilean moons. We will study the data in this region and analyze the intensity dropouts that are caused by the interaction between the particles that bounce along field lines and drift around the planet with the moons and associated gas and plasma tori. Also, we will analyze the rate of intensity change towards Jupiter that is determined by radial transport, potential local source processes, and the range of pitch angles that can reach the changing latitudes.

Nonlinear Representation and Pulse Testing of Communication Subsystems.

DTIC Science & Technology

1982-05-01

The Post-Doctoral Program provides an opportunity for faculty at participating universities to spend up to one year full time on explora- tory...development and problem-solving efforts with the post-doctorals splitting their time between the customer location and their educational institutions. The...CHAPTER II z-DOMAIN CHARACTERIZATION OF THE QUJADRATIC VOLTERRA SYSTEM................3 2.1 Continuous- Time Analysis .................. 3 Rational

The "Great Refusal"? A Marcusian Response to the Bright Blue Vision of Education in the "Big Society"

ERIC Educational Resources Information Center

Bates, Agnieszka

2015-01-01

The modernisation of education and other public services remains a major political objective of the current Coalition government in the UK. This paper focuses on "Tory Modernisation 2.0," a blueprint for the second stage of the public sector reform produced by the Conservative pressure group, Bright Blue. From the critical theory…

Half Way to Hell: What Gove Is Doing to England's Schools

ERIC Educational Resources Information Center

Gillard, Derek

2012-01-01

Following the indecisive general election in May 2010, the Tories and Liberal Democrats formed a coalition government with David Cameron as Prime Minister, George Osborne as Chancellor of the Exchequer, and Michael Gove as Secretary of State for Education. Right from the start, Gove was a man in a hurry. Within two weeks of his appointment he had…

High-Frequency Percussive Ventilation Revisited

DTIC Science & Technology

2010-01-01

be implemented. ‡ Follow the reverse of the ventilation sequence if respiratory alkalosis develops—however, start at ventilation goal sequence 1 not at...High-frequency percussive ventilation (HFPV) has demonstrated a potential role as a rescue option for refractory acute respiratory distress syndrome...frequency percussive ventilation (HFPV) has demon- strated a potential role as a salvage option for refrac- tory acute respiratory distress syndrome

Spontaneous Athermal Cross-Slip Nucleation at Screw Dislocation Intersections in FCC Metals and L1(2) Intermetallics Investigated via Atomistic Simulations

DTIC Science & Technology

2013-01-01

LAMMPS [12], developed at Sandia National Labora- tory. The simulation cell is a rectangular parallelepiped having the x-axis oriented along the [1 1 0...cross-slip during deformation. Acknowledgements The authors acknowledge use of the 3d molecular dynamics code, LAMMPS , which was developed at Sandia

Formation Flight of Earth Satellites on KAM Tori

DTIC Science & Technology

2007-09-01

satellite formations, involves using the Hill- Clohessy - Wiltshire (HCW) equations, created originally for the Gemini Program [2]. These equations are given...the Perturbed J2-Modified Hill- Clohessy - Wiltshire Equations. MS thesis, The University of Texas at Arlington, 2006. 7. Kaasalainen, M. and J. Binney...107 xvii List of Abbreviations Abbreviation Page KAM Kolmogorov, Arnold and Moser . . . . . . . . . . . . . . . . . 2 HCW Hill- Clohessy

Quasi-periodic accretion and gravitational waves from oscillating `toroidal neutron stars' around a Schwarzschild black hole

NASA Astrophysics Data System (ADS)

Zanotti, Olindo; Rezzolla, Luciano; Font, José A.

2003-05-01

We present general relativistic hydrodynamics simulations of constant specific angular momentum tori orbiting a Schwarzschild black hole. These tori are expected to form as a result of stellar gravitational collapse, binary neutron star merger or disruption, can reach very high rest-mass densities and behave effectively as neutron stars but with a toroidal topology (i.e. `toroidal neutron stars'). Here our attention is focused on the dynamical response of these objects to axisymmetric perturbations. We show that upon the introduction of perturbations, these systems either become unstable to the runaway instability or exhibit a regular oscillatory behaviour, resulting in a quasi-periodic variation of the accretion rate as well as of the mass quadrupole. The latter, in particular, is responsible for the emission of intense gravitational radiation for which the signal-to-noise ratio at the detector is comparable to or larger than the typical one expected in stellar-core collapse, making these new sources of gravitational waves potentially detectable. We discuss a systematic investigation of the parameter space in both the linear and non-linear regimes, providing estimates of how the gravitational radiation emitted depends on the mass of the torus and on the strength of the perturbation.

Lightweight bladder lined pressure vessels

DOEpatents

Mitlitsky, F.; Myers, B.; Magnotta, F.

1998-08-25

A lightweight, low permeability liner is described for graphite epoxy composite compressed gas storage vessels. The liner is composed of polymers that may or may not be coated with a thin layer of a low permeability material, such as silver, gold, or aluminum, deposited on a thin polymeric layer or substrate which is formed into a closed bladder using tori spherical or near tori spherical end caps, with or without bosses therein, about which a high strength to weight material, such as graphite epoxy composite shell, is formed to withstand the storage pressure forces. The polymeric substrate may be laminated on one or both sides with additional layers of polymeric film. The liner may be formed to a desired configuration using a dissolvable mandrel or by inflation techniques and the edges of the film sealed by heat sealing. The liner may be utilized in most any type of gas storage system, and is particularly applicable for hydrogen, gas mixtures, and oxygen used for vehicles, fuel cells or regenerative fuel cell applications, high altitude solar powered aircraft, hybrid energy storage/propulsion systems, and lunar/Mars space applications, and other applications requiring high cycle life. 19 figs.

Characterization of oil and gas reservoir heterogeneity; Final report, November 1, 1989--June 30, 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, G.D.

1993-09-01

The Alaskan North Slope comprises one of the Nation`s and the world`s most prolific oil province. Original oil in place (OOIP) is estimated at nearly 70 BBL (Kamath and Sharma, 1986). Generalized reservoir descriptions have been completed by the University of Alaska`s Petroleum Development Laboratory over North Slope`s major fields. These fields include West Sak (20 BBL OOIP), Ugnu (15 BBL OOIP), Prudhoe Bay (23 BBL OOIP), Kuparuk (5.5 BBL OOIP), Milne Point (3 BBL OOIP), and Endicott (1 BBL OOIP). Reservoir description has included the acquisition of open hole log data from the Alaska Oil and Gas Conservation Commissionmore » (AOGCC), computerized well log analysis using state-of-the-art computers, and integration of geologic and logging data. The studies pertaining to fluid characterization described in this report include: experimental study of asphaltene precipitation for enriched gases, CO{sup 2} and West Sak crude system, modeling of asphaltene equilibria including homogeneous as well as polydispersed thermodynamic models, effect of asphaltene deposition on rock-fluid properties, fluid properties of some Alaskan north slope reservoirs. Finally, the last chapter summarizes the reservoir heterogeneity classification system for TORIS and TORIS database.« less

The Phobos neutral and ionized torus

NASA Astrophysics Data System (ADS)

Poppe, A. R.; Curry, S. M.; Fatemi, S.

2016-05-01

Charged particle sputtering, micrometeoroid impact vaporization, and photon-stimulated desorption are fundamental processes operating at airless surfaces throughout the solar system. At larger bodies, such as Earth's Moon and several of the outer planet moons, these processes generate tenuous surface-bound exospheres that have been observed by a variety of methods. Phobos and Deimos, in contrast, are too gravitationally weak to keep ejected neutrals bound and, thus, are suspected to generate neutral tori in orbit around Mars. While these tori have not yet been detected, the distribution and density of both the neutral and ionized components are of fundamental interest. We combine a neutral Monte Carlo model and a hybrid plasma model to investigate both the neutral and ionized components of the Phobos torus. We show that the spatial distribution of the neutral torus is highly dependent on each individual species (due to ionization rates that span nearly 4 orders of magnitude) and on the location of Phobos with respect to Mars. Additionally, we present the flux distribution of torus pickup ions throughout the Martian system and estimate typical pickup ion fluxes. We find that the predicted pickup ion fluxes are too low to perturb the ambient plasma, consistent with previous null detections by spacecraft around Mars.

JPRS Report, Science & Technology, USSR: Science & Technology Policy

DTIC Science & Technology

1988-04-05

associa- tions—were formulated. Specialists, A. V. Glichev, direc- tor of the All-Union Institute of Metrology and Stan- dardization of the USSR State...Various functional subdi- visions—laboratories of reliability, metrological labora- tories, monitoring and diagnostic centers, and so forth— are...department for standards, metrology , and quality. The latter annually does not approve and sends back for modification up to 20 of the "notebooks of

Aquatic Plant Control Research Program. Alligatorweed Survey of Ten Southern States

DTIC Science & Technology

1988-04-01

Environmental Labora- tory (EL), US Army Engineer Waterways Experiment Station (WES). The author extends appreciation to Dr. Dana Sanders and Messrs. Edwin A...the WES Information Technology Laboratory. This study was conducted under the direct supervision of Mr. Edwin A. Theriot and Dr. Hanley K. Smith, Chief...agents producing in your area? ................................................... 22 0 10 Site 2--Steenson Hollow (Wilson Lake, Colbert County

2008 Annual Report TATRC

DTIC Science & Technology

2008-01-01

drugs such as Prozac . The QD probes, in collaboration with the Greengard Labora- tory at Rockefeller University, are also being used to study neural...ADDRESS(ES) US Army Medical Research and Materiel Command (USAMRMC),Telemedicine & Advanced Technology Research Center (TATRC),Fort Detrick,MD,21702 8...hasten a full return to duty and a fulfilling life.” — Major General George W. Weightman Commanding General, US Army Medical Research and Materiel

Alternative approaches to plasma confinement

NASA Technical Reports Server (NTRS)

Roth, J. R.

1977-01-01

The potential applications of fusion reactors, the desirable properties of reactors intended for various applications, and the limitations of the Tokamak concept are discussed. The principles and characteristics of 20 distinct alternative confinement concepts are described, each of which may be an alternative to the Tokamak. The devices are classed as Tokamak-like, stellarator-like, mirror machines, bumpy tori, electrostatically assisted, migma concept, and wall-confined plasma.

Stochastic Orbit Prediction Using KAM Tori

DTIC Science & Technology

2011-03-24

the plane . The debris was later identified as a reentering Russian Progress 23P cargo freighter for the ISS...elements. The eccentricity and angular momentum scalar quantities define the orbit in the plane [25:208]. The inclination, right ascension of the ascending...Since ⃑ is a constant vector perpendicular to ⃑ and ⃑ , the satellite’s motion is fixed in the plane containing ⃑ and ⃑ called the

Medical Aspects of Survival: Training for Aircrew

DTIC Science & Technology

1983-01-01

requirements for food and water. b. The environment - terrain, climate , flora and fauna, friendly or neutral natives, distance from friendly forces...the discomforts of colds and upper respiratory deseases , and at best, will just take the edge off severe pain. They should be taken, however, if...injury, either mechanical or emotional. Whilst the circula- tory changes initially favour body resistance to the injury by ensuring adequate blood

The Protean Shape of the Writing Associate's Role: An Empirical Study and Conceptual Model

ERIC Educational Resources Information Center

Cairns, Rhoda; Anderson, Paul V.

2008-01-01

Writing fellow or writing associate (WA) programs trace their heritage to a single point of origin: the model developed at Brown University in the early 1980s by Tori Haring-Smith (Soven, 1993, 2001). Since then, the Brown model has spread to hundreds of schools. WA programs are so adaptable because they consist of many discrete elements, each of…

The phase space of boxy-peanut and X-shaped bulges in galaxies - I. Properties of non-periodic orbits

NASA Astrophysics Data System (ADS)

Patsis, P. A.; Katsanikas, M.

2014-12-01

The investigation of the phase-space properties of structures encountered in a dynamical system is essential for understanding their formation and enhancement. In this paper, we explore the phase space in energy intervals where we have orbits that act as building blocks for boxy-peanut (b/p) and `X-shaped' structures in rotating potentials of galactic type. We underline the significance of the rotational tori around the 3D families x1v1 and x1v1' that have been bifurcated from the planar x1 family. These tori play a multiple role: (i) they belong to quasi-periodic orbits that reinforce the local density. (ii) They act as obstacles for the diffusion of chaotic orbits and (iii) they attract a large number of chaotic orbits that become sticky to them. There are also bifurcations of unstable families (x1v2, x1v2'). Their unstable asymptotic curves wind around the x1v1 and x1v1' tori generating orbits with hybrid morphologies between that of x1v1 and x1v2. In addition, a new family of multiplicity 2, called x1mul2, is found to be important for the peanut construction. This family produces stickiness phenomena in the critical area of the radial and vertical inner Lindblad resonances (ILRs) and reinforces b/p bulges. Our work shows also that there are peanut-supporting orbits before the vertical ILR. Non-periodic orbits associated with the x1 family secure this contribution as well as the support of b/p structures at several other energy intervals. Non-linear phenomena associated with complex instability of single and double multiplicity families of periodic orbits show that these structures are not interrupted in regions where such orbits prevail. Depending on the main mechanism behind their formation, boxy bulges exhibit different morphological features. Finally, our analysis indicates that `X' features shaped by orbits in the neighbourhood of x1v1 and x1v1' periodic orbits are pronounced only in side-on or nearly end-on views of the bar.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This report contains presentations presented at a technical symposium on oil production. Chapter 1 contains summaries of the presentations given at the Department of Energy (DOE)-sponsored symposium and key points of the discussions that followed. Chapter 2 characterizes the light oil resource from fluvial-dominated deltaic reservoirs in the Tertiary Oil Recovery Information System (TORIS). An analysis of enhanced oil recovery (EOR) and advanced secondary recovery (ASR) potential for fluvial-dominated deltaic reservoirs based on recovery performance and economic modeling as well as the potential resource loss due to well abandonments is presented. Chapter 3 provides a summary of the general reservoirmore » characteristics and properties within deltaic deposits. It is not exhaustive treatise, rather it is intended to provide some basic information about geologic, reservoir, and production characteristics of deltaic reservoirs, and the resulting recovery problems.« less

Humboldt Bay Wetlands Review and Baylands Analysis. Volume I. Summary and Findings.

DTIC Science & Technology

1980-08-01

the best and most compatible economic, environmental, and social uses of the Humboldt Bay area. Such data includes inven- tories of uses and conditions... personal communication). Since 1973, 22 general permits have been granted by the Harbor District; of these, there were 3 for submarine pipeline/cable...other water charateristics determine the type and abundance. Distribution Water habitats are distributed throughout the study area. Deep and shallow

Low Titer Group O Whole Blood in Emergency Situations

DTIC Science & Technology

2014-01-01

ABO incompatibility is defined as transfusion of donor anti-A and/or anti-B to a patient whose RBCs carry A or B antigens . Clinical consequences are...typically minor and frequently subclinical (12). Platelet transfusions with ABO- incompatible plasma occur routinely in hospitals in the United States...minor ABO incompatibility as nonidentical platelet transfusion . It is therefore a paradox that in some countries the regula- tory authorities have

The AFIT of Today is the Air Force of Tomorrow

DTIC Science & Technology

2012-05-11

Engineering • Operations Research • Space Systems • Systems Engineering • Air Mobility • Combating Weapons of Mass Destruction • Cost Analysis • Cyber...Fight - Win Graduate Certificate Programs • Systems Engineering • Space Systems • Advanced Geospatial Intelligence • Combating Weapons of Mass ...over five years • Critical enabler for SSA: extending the satellite catalog to small objects Current Works: • Converting satellite catalog to KAM Tori

Approach to the Pediatric Patient with Graves’ Disease: When Is Definitive Therapy Warranted?

DTIC Science & Technology

2011-03-01

disease (AITD; GD and autoimmune hypothyroid - ism) has provided evidence for involvement of several loci, including the human leukocyte antigen (HLA...Fluctuating levels of the stimula- tory and inhibitory antibodies can result in an alternating clinical presentation between hyper- and hypothyroidism ...Hepatitis Joint pain Arthralgia J Clin Endocrinol Metab, March 2011, 96(3):580–588 jcem.endojournals.org 583 hypothyroidism . The limiting factor for

Development and Validation of a PTSD-Related Impairment Scale

DTIC Science & Technology

2012-06-01

Social Adjustment Scale (SAS-SR) (58] Dyadic Adjustment Scale (DAS) [59] Life Stressors and Social Resources Inventory ( LISRES ) [60] 3...measure that gauges on- 200 Social Resources lnven- 2. Spouse/partner going life stressors and social resources tory ( LISRES ; Moos & 3. Finances as well...measures (e.g., ICF checklist, LISRES ; Moos, Penn, & Billings, 1988) may nor be practical or desirable in many healthcare settings or in large-scale

GOES-S Prelaunch News Conference

NASA Image and Video Library

2018-02-27

GOES-S Prelaunch News Conference hosted by NASA Communications' Tori Mclendon, with Stephen Volz, Director for Satellite and Information Services, NOAA; Tim Walsh, GOES-R system program director (acting), NOAA; Sandra Smalley, Director, NASA Joint Agency Satellite Division; Tim Dunn, NASA Launch Director, Kennedy Space Center, Florida; Scott Messer, Program Manager, NASA Missions, United Launch Alliance; and Kathy Winters, Launch Weather Officer, 45th Weather Squadron, Cape Canaveral Air Force Station, Florida.

Von Willebrand’s Disease

DTIC Science & Technology

1990-01-01

developing human immunodefi- ANTIFIBRINOLYTIC AGENTS ciency virus (HIV) antibody after receiving Aminocaproic acid (Amicar) and tran- seronegative...8-0 In most Aminocaproic acid can be used in oral patients, treatment is also associated with or intravenous forms. In adults, the oral a rise in the...she was eight years of age. She had no his- caproic acid before the procedure and for tory of bruising or menorrhagia. the next 48 hours. No

Targeting B7x and B7-H3 as New Immunotherapies for Prostate Cancer

DTIC Science & Technology

2017-11-01

treat rheumatoid arthritis and prevent acute kidney transplant rejection (Fiocco et al., 2008; Vincenti et al., 2011). The past decade has witnessed a...cell lines. The first Phase I trial with pidilizumab recruited patients with hematologic malignancies, including acute myeloid leukemia (AML), chronic... radiation , chemotherapy, other coinhibi- tory antibodies, or vaccines can improve the response rate in cancers. Predictive biomarkers need to be developed

Formal Mentoring in the U.S. Military: Research Evidence, Lingering Questions, and Recommendations

DTIC Science & Technology

2010-01-01

mentoring outcomes in civilian organizations reveal that mentoring clearly fosters career success .6 Across organizations, settings, and research de- signs...general career competence. Al- though a variety of other variables clearly influence career success (e.g., ability, personality, motivation), it is...of Career Success in the Military. At times, or- ganizations are smitten with the idea of mentoring; charging ahead with manda- tory mentoring

The Role of Claudin-7 in Mouse Mammary Gland and Tumorigenesis

DTIC Science & Technology

2004-07-01

days with minimal inflamma- tory response; however, significant mastitis was observed 12 days after transduction. Adenovirus transduction could also...be used in the virgin animal with little mastitis 3 days after transduction. Transduced mammary epithelial cells maintained normal morphology and...34Clstu- Breeding ILaboratory (Wilmington, Mass.) and maintained in the U.S. Depart- crose permeability is one of the hallmarks of mastitis (9), we used

Polarimeter Blind Deconvolution Using Image Diversity

DTIC Science & Technology

2007-09-01

significant presence when imaging through turbulence and its ease of production in the labora- tory. An innovative algorithm for detection and estimation...1.2.2.2 Atmospheric Turbulence . Atmospheric turbulence spatially distorts the wavefront as light passes through it and causes blurring of images in an...intensity image . Various values of β are used in the experiments. The optimal β value varied with the input and the algorithm . The hybrid seemed to

Evaluation of Electromagnetic Induction (EMI) Resistivity Technologies for Assessing Permafrost Geomorphologies

DTIC Science & Technology

2016-08-01

Structures Laboratory MCMC Markov Chain Monte Carlo NAPL Non -Aqueous Phase Liquids ppm Parts per Million R&D Research and Development SERDP... Research Engineering Labora- tory (CRREL) and Fridon Shubitidze at Dartmouth College lead a research group that has constructed several research -grade...by Bar- rowes’ research group to obtain EC over lines or areas. Another possibility is to use unmanned helicopters to acquire data over larger areas

Studies of Phlebotomine Sand Flies.

DTIC Science & Technology

1980-08-31

coils. Holotype, allotype and 20 paratypes to be deposited at Instituto Nacional de Pesquisas da Amazonia , Manaus. Other para- types in Brazilian...collections at Universidad Federal de Minas Gerais and S~o Paulo; Instituto Oswaldo Cruz, Rio de Janeiro; Instituto Evandro Chagas, Be16m; Museu Paraense...of Mr. Joao Ferreira Vidal in the field and labora- tory. Literature Cited Floch, H. & E. Abonnenc. 1943. Phl~botomes de la Guyane Franqaise - v. Inst

Holding Capacity of Plate Anchors

DTIC Science & Technology

1980-10-01

Engineering Laboratory, Technical Report R-855. Port Hueneme, Calif., Jul 1977. Lee, H. J., and J. E . Clausner (1979). Seafloor soil sampling and...hesionless is manda- tory. Classification by the Unified Soil (lassification System is preferable. ( e ) Permeability- Required when cyclic load capacity is...mally consolidated, and (3) underconsolidated. *Formerly V.S Coast an] (; e .,letic Surk,’-,, !, S Dc ;trlnln1 ,f Commc re. 1 9 E t -. - - --- - 20 I CL I

The theory of pseudo-differential operators on the noncommutative n-torus

NASA Astrophysics Data System (ADS)

Tao, J.

2018-02-01

The methods of spectral geometry are useful for investigating the metric aspects of noncommutative geometry and in these contexts require extensive use of pseudo-differential operators. In a foundational paper, Connes showed that, by direct analogy with the theory of pseudo-differential operators on finite-dimensional real vector spaces, one may derive a similar pseudo-differential calculus on noncommutative n-tori, and with the development of this calculus came many results concerning the local differential geometry of noncommutative tori for n=2,4, as shown in the groundbreaking paper in which the Gauss-Bonnet theorem on the noncommutative two-torus is proved and later papers. Certain details of the proofs in the original derivation of the calculus were omitted, such as the evaluation of oscillatory integrals, so we make it the objective of this paper to fill in all the details. After reproving in more detail the formula for the symbol of the adjoint of a pseudo-differential operator and the formula for the symbol of a product of two pseudo-differential operators, we extend these results to finitely generated projective right modules over the noncommutative n-torus. Then we define the corresponding analog of Sobolev spaces and prove equivalents of the Sobolev and Rellich lemmas.

Chaotic Transport in Circumterrestrial Orbits

NASA Astrophysics Data System (ADS)

Rosengren, Aaron Jay

2018-04-01

The slow deformation of circumterrestrial orbits in the medium region, subject to lunisolar secular resonances, is well approximated by a Hamiltonian system with 2.5 degrees of freedom. This dynamical model is referred to in the astrophysical and celestial dynamics communities as the quadrupolar, secular, hierarchical three-body problem, and, in the non-autonomous case, gives rise to the classical Kozai-Lidov mechanism. In the time-dependent model, brought about in our case by the Moon's perturbed motion, the action variables of the system may experience chaotic variations and large drifts due to the possible overlap of nearby resonances. Using variational chaos indicators, we compute high-resolution portraits of the action space, revealing the existence of tori and structures filling chaotic regions. Our refined and elaborate calculations allow us to isolate precise initial conditions near specific areas of interest and to study their asymptotic behavior in time. We highlight in particular how the drift in phase space is mediated by the complement of the numerically detected KAM tori. Despite their reputed normality, Earth satellite orbits can possess an extraordinarily rich spectrum of dynamical behaviors, and, like the small body remnants of Solar system formation, they have all the complications that make them very interesting candidates for testing the modern tools of chaos theory.

Issues in measure-preserving three dimensional flow integrators: Self-adjointness, reversibility, and non-uniform time stepping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finn, John M., E-mail: finn@lanl.gov

2015-03-15

Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a “special divergence-free” (SDF) property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint.more » We also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Feng and Shang [Numer. Math. 71, 451 (1995)], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Richardson and Finn [Plasma Phys. Controlled Fusion 54, 014004 (2012)], appears to work very well.« less

Research Needs: Prime-Power for High Energy Space Systems.

DTIC Science & Technology

1982-06-01

nuclear sources included both developments from earlier NASA/AEC efforts, such as the present SP-100 program , and also advanced concepts in the form of...and, in some cases, set aside). major programs of applied-research and exploratory- development exist at AFWAL and at NASA labora- tories. The results...decades. In such a research program , the particular I problems of a specific device presently under development are less important than the creation of

Correlation of Chemical Characteristics with Fuel Properties by Gas Chromatography.

DTIC Science & Technology

1981-12-01

Ai2i 788 CORRELATION OF CHEMICAL CHARACTERISTICS WITH FUEL / PROPERTIES BY GAS CHROM ..(U) SOUTHWEST RESEARCH INST SAN ANTONIO TX ARMY FUELS AND...to provide peak resolution comparable to, but somewhat improved over those currently in use at the Aero Propulsion Labora- * tory where similar fuels...Chromatographic Science, Vol. 13, February 1975. 18. Stavinoha, L.L., "Boiling Point Distribution of Gasoline by Gas Chrom - atography," U.S. Army Fuels

Computerized Decision Support System Improves Fluid Resuscitation Outcomes Following Severe Burns: An Original Study

DTIC Science & Technology

2011-01-01

clinical decision- making paradigms, coupled with regula- tory and technical limitations, is just one of the hurdles that has kept advanced information...responses to assist care personnel during the resuscitation phase. CDSSs have been successfully used in the clinical setting for several years (23–24...because of clinical complications, death, or other factors were excluded. The control cohort included only patients who sur- vived for the initial 24

The Chinese Air Force: Evolving Concepts, Roles, and Capabilities

DTIC Science & Technology

2012-01-01

5 The Missions of the People’s Liberation Army Air Force . . . 133 Murray Scot Tanner Chapter 6 The Development of the PLAAF’s Doctrine...the Military Region (MR) Headquarters. There are no indications this pattern of army domination will change in the next decade.” Murray Scot Tanner, a...his- tory, one can find remarkable threads of continuity. Early aircraft, though but fragile contraptions of wood and canvas, exploited the same

Hybrid Warfare Dilemmas in the Middle Colonies during the American Revolution

DTIC Science & Technology

2017-05-25

Livingston spoke of the fight against the Loyalists in fall of 1777 stating, “A Tory is an incorrigible Animal : And nothing but the extinction of...defensive capabilities in legitimate service to the state or alliance. Training Circular (TC) 7- 100 , Hybrid Threat (Washington, DC: Government Printing...10 TC- 100 , 1-2. 6 the Army as part of a Joint Force presents adversaries with multiple dilemmas to achieve sustainable

Chimera states in an ensemble of linearly locally coupled bistable oscillators

NASA Astrophysics Data System (ADS)

Shchapin, D. S.; Dmitrichev, A. S.; Nekorkin, V. I.

2017-11-01

Chimera states in a system with linear local connections have been studied. The system is a ring ensemble of analog bistable self-excited oscillators with a resistive coupling. It has been shown that the existence of chimera states is not due to the nonidentity of oscillators and noise, which is always present in real experiments, but is due to the nonlinear dynamics of the system on invariant tori with various dimensions.

NRL Fact Book

DTIC Science & Technology

1989-04-01

house research labora- tory under the command of the Chief of Naval Research (CNR). As the corporate research laboratory of the Navy, NRL is an important...L.S. Herrin Ms. B.J. McDonald Mr. R.C. Spragg Ms. M.E. Barton Ms. J. Hileman Title Head, Office of Management and Administration Deputy Head...Administrative Officer Head, Management Information Staff Head, Directives Staff Head, GLISIP Program Point of contact: Ms. B.J. McDonald , Code 1005.2, 767-3634

Resolving Ethical Challenges in an Era of Persistent Conflict

DTIC Science & Technology

2011-04-01

pleasure. For John Stuart Mill , it was hap- piness. Others consider it interest or well-being. In the context of 36 Just War thinking, the good is...war. THE PROFESSIONAL MILITARY ETHIC: BALANCING RISK Accomplishing the Mission. Military ethics begins with the utilitarian im- perative to...avoid defeat are not just permissible, they are obliga- tory. Additionally, it is a feature of any utilitarian ethic that the greater the good, the

Computational Identification of Mechanistic Factors That Determine the Timing and Intensity of the Inflammatory Response

DTIC Science & Technology

2016-05-09

inflammation. Author Summary A recent approach to quantitatively characterize the timing and intensity of the inflamma- tory response relies on the use of...Fig 1). The quantitative properties of these trajecto- ries vary as a result of differences in inflammatory conditions and scenarios. Recently, four... quantitative indices [namely, peak height (Cmax), activation time (Tact), resolution interval (Ri), and resolution plateau (Rp)] (Fig 1) were introduced

Manual for Courts-Martial, United States, 1984. 1994 Edition.

DTIC Science & Technology

1994-01-01

cards, forensic labora- that office. tory reports, chain of custody documents, morning (15) Statements in documents ajfecting an interest in reports...Para. 142e of the 1969 Manual, "Polygraph tests and drug-in- gate witnesses. This provision generally restates prior law but rec- duced or hypnosis ...statements of the person in- Rule 615. Exclusion of witnesses terviewed made during a drug-induced or hypnosis -induced inter- Rule 615 is taken from the f

Miracles Can Happen: The Unification of Post Partisan Revolutionary South Carolina

DTIC Science & Technology

2009-01-01

happiness but also believed in personal freedom from the freedom of speech , freedom of thought, freedom of conscience, and the right to property. All...town. Cornwallis’s officers, believing the Presbyterian Church was equivalent to “ sedition shops”, burnt down as many churches as possible to punish...establishment of the state’s government. Private retribution and crimes against Tories were not tolerated. The lessons from the Regulator movement twenty

Topological analysis of the motion of an ellipsoid on a smooth plane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ivochkin, M Yu

2008-06-30

The problem of the motion of a dynamically and geometrically symmetric heavy ellipsoid on a smooth horizontal plane is investigated. The problem is integrable and can be considered a generalization of the problem of motion of a heavy rigid body with fixed point in the Lagrangian case. The Smale bifurcation diagrams are constructed. Surgeries of tori are investigated using methods developed by Fomenko and his students. Bibliography: 9 titles.

POPE: Partial Order Preserving Encoding

DTIC Science & Technology

2016-09-09

Alex X. Liu, Ann L. Wang, and Bezawada Bruhadeshwar. Fast range query processing with strong privacy protection for cloud computing . Proc. VLDB...States government. As such, the Government retains a nonexclusive, royalty-free right to publish or reproduce this article , or to allow others to do so...of these schemes the direc- tory in the persistent client storage depends on the full dataset. Thus 1We abuse notation and use OPE to refer to both

Damped response of shells by a constrained viscoelastic layer

NASA Technical Reports Server (NTRS)

El-Raheb, M.; Wagner, P.

1986-01-01

Vibration absorbers are introduced into an asymmetric configuration of thin cylinders and tori enclosing an acoustic medium. The absorbers consist of thin axial strips bonded to the cylinder with a thin viscoelastic layer. The constrained layer dissipates the energy of relative motions between strip and cylinder. The absorber is most effective on response modes with two or more circumferential waves. The use of transfer matrices is extended to the coupled cylinder-absorber system.

Food and Drug Administration: Insufficient Planning for Field Laboratory Consolidation Decisions.

DTIC Science & Technology

1987-12-04

adequately 5 address whether FDA could meet its current and future laboratory needs if the five laboratories were closed or whether cost- effective ...pie transit and laboratory processing times would lessen FDA’S regula- tory effectiveness . Moreover, 61 percent of the excess laboratory capacity...FDA believes that it can ship sam- pies from across the nation to almost any location for analysis without reducing its regulatory effectiveness . (See

Adaptive Control Techniques for Large Space Structures

DTIC Science & Technology

1987-12-23

articles : 41Y’ 4 C - . L) , /V., .**~ V .- ~ ~ __5 -. . ,- . /- . # \\J . . _ I- / ’ ~ - L r,:0- ,*~ ~ . 20 OISTRIBUTION/AVAILABILITY OF AUSTt CT 21...up by the strong theoretical foundations in Ljung(1987) and in Anderson et al.(1986), that results can be obtained which will be of scientific value...has, of course, a long his- tory, and we will not attempt to document that here. There are many excellent survey articles and textbooks that can be

Parsec-Scale Obscuring Accretion Disk with Large-Scale Magnetic Field in AGNs

NASA Technical Reports Server (NTRS)

Dorodnitsyn, A.; Kallman, T.

2017-01-01

A magnetic field dragged from the galactic disk, along with inflowing gas, can provide vertical support to the geometrically and optically thick pc (parsec) -scale torus in AGNs (Active Galactic Nuclei). Using the Soloviev solution initially developed for Tokamaks, we derive an analytical model for a rotating torus that is supported and confined by a magnetic field. We further perform three-dimensional magneto-hydrodynamic simulations of X-ray irradiated, pc-scale, magnetized tori. We follow the time evolution and compare models that adopt initial conditions derived from our analytic model with simulations in which the initial magnetic flux is entirely contained within the gas torus. Numerical simulations demonstrate that the initial conditions based on the analytic solution produce a longer-lived torus that produces obscuration that is generally consistent with observed constraints.

Parsec-scale Obscuring Accretion Disk with Large-scale Magnetic Field in AGNs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorodnitsyn, A.; Kallman, T.

A magnetic field dragged from the galactic disk, along with inflowing gas, can provide vertical support to the geometrically and optically thick pc-scale torus in AGNs. Using the Soloviev solution initially developed for Tokamaks, we derive an analytical model for a rotating torus that is supported and confined by a magnetic field. We further perform three-dimensional magneto-hydrodynamic simulations of X-ray irradiated, pc-scale, magnetized tori. We follow the time evolution and compare models that adopt initial conditions derived from our analytic model with simulations in which the initial magnetic flux is entirely contained within the gas torus. Numerical simulations demonstrate thatmore » the initial conditions based on the analytic solution produce a longer-lived torus that produces obscuration that is generally consistent with observed constraints.« less

The Structure of Active Galactic Nuclei

NASA Technical Reports Server (NTRS)

Kriss, Gerard A.

1997-01-01

We are continuing our systematic investigation of the nuclear structure of nearby active galactic nuclei (AGN). Upon completion, our study will characterize hypothetical constructs such as narrow-line clouds, obscuring tori, nuclear gas disks. and central black holes with physical measurements for a complete sample of nearby AGN. The major scientific goals of our program are: (1) the morphology of the NLR; (2) the physical conditions and dynamics of individual clouds in the NLR; (3) the structure and physical conditions of the warm reflecting gas; (4) the structure of the obscuring torus; (5) the population and morphology of nuclear disks/tori in AGN; (6) the physical conditions in nuclear disks; and (7) the masses of central black holes in AGN. We will use the Hubble Space Telescope (HST) to obtain high-resolution images and spatially resolved spectra. Far-UV spectroscopy of emission and absorption in the nuclear regions using HST/FOS and the Hopkins Ultraviolet Telescope (HUT) will help establish physical conditions in the absorbing and emitting gas. By correlating the dynamics and physical conditions of the gas with the morphology revealed through our imaging program, we will be able to examine mechanisms for fueling the central engine and transporting angular momentum. The kinematics of the nuclear gas disks may enable us to measure the mass of the central black hole. Contemporaneous X-ray observations using ASCA will further constrain the ionization structure of any absorbing material. Monitoring of variability in the UV and X-ray absorption will be used to determine the location of the absorbing gas, possibly in the outflowing warm reflecting gas, or the broad-line region, or the atmosphere of the obscuring torus. Supporting ground-based observations in the optical, near-IR, imaging polarimetry, and the radio will complete our picture of the nuclear structures. With a comprehensive survey of these characteristics in a complete sample of nearby AGN, our conclusions should be more reliably extended to AGN as a class.

Identification of Complex Carbon Nanotube Structures

NASA Technical Reports Server (NTRS)

Han, Jie; Saini, Subhash (Technical Monitor)

1998-01-01

A variety of complex carbon nanotube (CNT) structures have been observed experimentally. These include sharp bends, branches, tori, and helices. They are believed to be formed by using topological defects such as pentagons and heptagons to connect different CNT. The effects of type, number, and arrangement (separation and orientation) of defects on atomic structures and energetics of complex CNT are investigated using topology, quantum mechanics and molecular mechanics calculations. Energetically stable models are derived for identification of observed complex CNT structures.

Iraq’s Shia Warlords and Their Militias: Political and Security Challenges and Options

DTIC Science & Technology

2015-06-01

Middle East his- tory and Arabic. He has studied and traveled widely in the Middle East. ix SUMMARY As America’s de facto co-belligerents who often...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army War College,Strategic Studies Institute,47 Ashburn Drive,Carlisle...routinely engage in discourse and debate concerning the role of ground forces in achieving national security objectives. The Strategic Studies Institute

Quantization of noncompact coverings and its physical applications

NASA Astrophysics Data System (ADS)

Ivankov, Petr

2018-02-01

A rigorous algebraic definition of noncommutative coverings is developed. In the case of commutative algebras this definition is equivalent to the classical definition of topological coverings of locally compact spaces. The theory has following nontrivial applications: • Coverings of continuous trace algebras, • Coverings of noncommutative tori, • Coverings of the quantum SU(2) group, • Coverings of foliations, • Coverings of isospectral deformations of Spin - manifolds. The theory supplies the rigorous definition of noncommutative Wilson lines.

Interactions of Neuromodulators with Cells of the Immune System

DTIC Science & Technology

1991-06-20

that cyclic AMP (cAMP), minoxidil and norepinephrine inhibit ConA- mediated lymphocyte activation. These experiments test the effects of these... minoxidil or 8x0W1M norepinephrine markedly inhibited IL2 activation (95%, 50% and 60% respec- tively) and showed similar effects in a ConA-activated...and 2) suggest that the inhibi- tory effects of cAMP, minoxidil and norepinephrine occur at points distal to 1L2 interaction in the lymphocyte

An Examination of the Effect of External Influences on the Soviet Negotiation Position in Post 1962 Arms Control Agreements

DTIC Science & Technology

1978-06-09

Bolsheviks inherited not only the geography and • natural resources of Russia, but also the people and the his- tory and the culture. While Marxism ...international disarmament, but rather the arming of the proletariat for the purpose of disarming and defeating the bourgeoisie . <hough Maxim Litvinov, the...Drachkovitch, Milorad M, Marxism in the Modern World, Stanford, CA: Stanford University Press, 1965. Fainsod, Merle. How Russia-is Ruled, Cambridges

Extremely Low Frequency (ELF) Communications System Ecological Monitoring Program: Plan and Summary of 1982 Progress.

DTIC Science & Technology

1983-08-01

Program Acquisition Schedule A-8 LIST OF TABLES TABLE TITLE Page 1 Evolution of the ELF Communications Ecological 2 Moni tori ng Program 2 Summary of...performed on plots in maple-dominant, mixed hardwood stands in Michigan. NATIVE BEES Bees are important pollinators of flowering plants and are...SMALL MAMMALS AND NESTING BIRDS Small mammals and nesting birds represent an ecological level inter- mediate between plants and strict carnivores

The American Military on the Frontier

DTIC Science & Technology

1976-04-01

1783. Ncrvian: University of ÖFlahoma Press, HeT. (E OQ iC9 ^7^) Flison, John 1753?-17’𔄂. The discovery and settlement of Kentucke. Ann ...8217■" Fremont, John Charles, 1813-1890. Peport of the explorlmT expedition to the Pocky Ntountalns. Ann Arbor, Michigan: Uhlverslty Vlcrofllnis...O/erslze F 592 P63e) . Sources of the Mississippi and the V.’eytem Lculrlqm ’"terri- tory. Ann Arbor. ^Ich.: Ur.lversltv Microfilms

Combat-Related Mental Health Disorders: The Case for Resiliency in The Long War

DTIC Science & Technology

2010-09-01

Upper ranges include suicide costs. Costs were estimated using a model that projected costs incurred during a soldier’s first 2 years after returning...JAOA • Vol 110 • No 9 • September 2010 The stress-CARE personality model describes cognitive, affective, and self-regulatory traits as the precursors...can be either positive or negative. The self-regula- tory traits are self-control and goal orientation. The stress-CARE model makes relatively specific

Department of Clinical Investigation Annual Research Progress Report, Fiscal Year 1985. Volume 2,

DTIC Science & Technology

1985-10-01

Objective(s): To study the feasibility of cytosine arabinoside (ara-C), used in high dosage in conjunction with fractionated total body irradiation... Using High Dose Ara-C 335 in Adult Acute Leukemia and Chronic Granulocytic Leukemia in Blastic Crisis, Phase III. (0) SWOG 8328 Evaluation of...Fludarabine Phosphate in Cervical Cancer, 336 Phase II. (0) SWOG 8360 Use of the Surgically Implanted "Infusaid" Pump for Ambula- 337 tory Ottpatient Hepatic

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Tori McLendon of NASA Communications, speaks to guests at an event celebrating the 60th anniversary of America's first satellite. The ceremony took place in front of the Space Launch Complex 26 blockhouse at Cape Canaveral Air Force Station where the Explorer 1 satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Individual Differences in Dual Task Performance.

DTIC Science & Technology

1981-06-10

SJCURITY CLASSIFICATION OF THIS PAGE("en Data Entered) second experimental series, we compared ability to detect visual and audi- tory targets in single...used performance on a simple secondary task executed during an easy primary task to predict performance on a more diffi- cult’version of the same...process concepts developed b’j cognitive ps:choloqists°’ In this laborators, we adapted a number of experimental tasks to 4ield individual measures of the

Report on Research at AFGL, January 1979-December 1980.

DTIC Science & Technology

1982-04-01

Labora- tory. It covers a two-year interval. Although written primarily for Air Force and DOD managers of research and development it is intended to...also includes an introductory chap- ter on AFGL management and logistic activities related to the reporling period. DD IJAN73 1473 EDITIONO I NOV 6S IS...the Air Force Cambridge Research Laboratories (AFCRL). Written primarily for Air Force and DOD managers of research and devel- opment, it shows how

Modeling Interactions Between Flexible Flapping Wing Spars, Mechanisms, and Drive Motors

DTIC Science & Technology

2011-09-01

of dynamical equations is presented that allow micro air vehicle (MAV) or- nithopter designers to match drive motors to loads produced by flexible...aeroelastic systems is presented. One potential use for such a model is to serve as the basis for a vehicle design tool that matches drive motors to loads...friction. ∗Senior Aerospace Engineer, Control Design and Analysis Branch, 2210 Eighth Street, Ste. 21, Air Force Research Labora- tory, WPAFB, OH 45433

Resonant torus-assisted tunneling.

PubMed

Yi, Chang-Hwan; Yu, Hyeon-Hye; Kim, Chil-Min

2016-01-01

We report a new type of dynamical tunneling, which is mediated by a resonant torus, i.e., a nonisolated periodic orbit. To elucidate the phenomenon, we take an open elliptic cavity and show that a pair of resonances localized on two classically disconnected tori tunnel through a resonant torus when they interact with each other. This so-called resonant torus-assisted tunneling is verified by using Husimi functions, corresponding actions, Husimi function distributions, and the standard deviations of the actions.

The Cause of Hypoglycemia in Dogs Exposed to Heat

DTIC Science & Technology

1959-06-01

the In 2 previously unused dogs we decided respiratory alkalosis . In a series of 11 ex- to produce a combined metabolic and respira- I periments the...Just above control metabolic alkalosis with a respiratory alkalosis . values at the end of 4 1hours. Evidently acid The animal could not satisfactorily...While a combined respiratory and wi~abolic alkalosis is a serfius strain on the regu-tory 1.T tae Insulin a do uuisllke ato NOl mechanism, some animals

Translations on South and East Asia No. 707

DTIC Science & Technology

1977-03-23

BERSENJATA, 6 Dec 76) 48 Austrian French Paper Mills Planned for Kalimantan (SUARA KARYA, 9 Dec 76) 50 Seven Rubber Mills Close in Sumatra (KOMPAS, 2...Indonesia to finance the liquified natural gas (LNG) projectsrin Bakan, East Kalimantan and Arun, Aceh. This was made 2 years before Morgan Guaranty Trust...coal surveys, most of which will be used for Ombilin coal deposit exploration. A part of the sum will also be used for prepara- tory geological

Handbook for Construction of Task Inventories for Navy Enlisted Ratings

DTIC Science & Technology

1984-01-01

1 March 1977. Cambardella, J. J. 9., & Alvord, V. 0. TI-CODAP: A computerized method of Aob analysis for personnel nasement. Prince George’s County...ficity needed In the occupational analysis and influences the choice of an analysis method . The primary source of job data usually is the job holder at...analyzed, various methods of collecting and procersing data were considered, and an Introduc- tory approach to the collection and analysis of Navy

The distribution of Enceladus water-group neutrals in Saturn’s Magnetosphere

NASA Astrophysics Data System (ADS)

Smith, Howard T.; Richardson, John D.

2017-10-01

Saturn’s magnetosphere is unique in that the plumes from the small icy moon, Enceladus, serve at the primary source for heavy particles in Saturn’s magnetosphere. The resulting co-orbiting neutral particles interact with ions, electrons, photons and other neutral particles to generate separate H2O, OH and O tori. Characterization of these toroidal distributions is essential for understanding Saturn magnetospheric sources, composition and dynamics. Unfortunately, limited direct observations of these features are available so modeling is required. A significant modeling challenge involves ensuring that either the plasma and neutral particle populations are not simply input conditions but can provide feedback to each population (i.e. are self-consistent). Jurac and Richardson (2005) executed such a self-consistent model however this research was performed prior to the return of Cassini data. In a similar fashion, we have coupled a 3-D neutral particle model (Smith et al. 2004, 2005, 2006, 2007, 2009, 2010) with a plasma transport model (Richardson 1998; Richardson & Jurac 2004) to develop a self-consistent model which is constrained by all available Cassini observations and current findings on Saturn’s magnetosphere and the Enceladus plume source resulting in much more accurate neutral particle distributions. Here a new self-consistent model of the distribution of the Enceladus-generated neutral tori that is validated by all available observations. We also discuss the implications for source rate and variability.

Symmetry-breaking Hopf bifurcations to 1-, 2-, and 3-tori in small-aspect-ratio counterrotating Taylor-Couette flow.

PubMed

Altmeyer, S; Do, Y; Marques, F; Lopez, J M

2012-10-01

The nonlinear dynamics of Taylor-Couette flow in a small-aspect-ratio wide-gap annulus in the counterrotating regime is investigated by solving the full three-dimensional Navier-Stokes equations. The system is invariant under arbitrary rotations about the axis, reflection about the annulus midplane, and time translations. A systematic investigation is presented both in terms of the flow physics elucidated from the numerical simulations and from a dynamical system perspective provided by equivariant normal form theory. The dynamics are primarily associated with the behavior of the jet of angular momentum that emerges from the inner cylinder boundary layer at about the midplane. The sequence of bifurcations as the differential rotation is increased consists of an axisymmetric Hopf bifurcation breaking the reflection symmetry of the basic state leading to an axisymmetric limit cycle with a half-period-flip spatiotemporal symmetry. This undergoes a Hopf bifurcation breaking axisymmetry, leading to quasiperiodic solutions evolving on a 2-torus that is setwise symmetric. These undergo a further Hopf bifurcation, introducing a third incommensurate frequency leading to a 3-torus that is also setwise symmetric. On the 3-torus, as the differential rotation is further increased, a saddle-node-invariant-circle bifurcation takes place, destroying the 3-torus and leaving a pair of symmetrically related 2-tori states on which all symmetries of the system have been broken.

Poloidal and toroidal plasmons and fields of multilayer nanorings

NASA Astrophysics Data System (ADS)

Garapati, K. V.; Salhi, M.; Kouchekian, S.; Siopsis, G.; Passian, A.

2017-04-01

Composite and janus type metallodielectric nanoparticles are increasingly considered as a means to control the spatial and temporal behavior of electromagnetic fields in diverse applications such as coupling to quantum emitters, achieving invisibility cloaks, and obtaining quantum correlations between qubits. We investigate the surface modes of a toroidal nanostructure and obtain the canonical plasmon dispersion relations and resonance modes for arbitrarily layered nanorings. Unlike particle plasmon eigenmodes in other geometries, the amplitudes of the eigenmodes of tori exhibit a distinct forward and backward coupling. We present the plasmon dispersion relations for several relevant toroidal configurations in the quasistatic limit and obtain the dominant retarded dispersion relations of a single ring for comparison, discuss mode complementarity and hybridization, and introduce two new types of toroidal particles in the form of janus nanorings. The resonance frequencies for the first few dominant modes of a ring composed of plasmon supporting materials such as gold, silver, and aluminum are provided and compared to those for a silicon ring. A generalized Green's function is obtained for multilayer tori allowing for calculation of the scattering response to interacting fields. Employing the Green's function, the scalar electric potential distribution corresponding to individual poloidal and toroidal modes in response to an arbitrarily polarized external field and the field of electrons is obtained. The results are applied to obtain the local density of states and decay rate of a dipole near the center of the torus.

Astronomía gamma con telescopios Cherenkov: hacia un observatorio astronómico abierto a la comunidad

NASA Astrophysics Data System (ADS)

Rovero, A. C.

Gamma-ray astronomy is opening the way to a universe far more energetic than anyone could have imagined half a century ago. The understanding of the processes of nature which carry a large portion of the energy in the universe, has astrophysical and cosmological implications. The next gen- eration of Cherenkov telescopes, an order of magnitude more sensitive and with higher resolution than the current systems, will mean a significant step forward for ground-based gamma-ray astronomy. This paper presents the current status of this field as well as the next generation of telescopes in this energy range, which are being designed for the first international observa- tory open to the astronomical community. The Cherenkov Telescope Array project and the Argentine sites proposed for the southern observatory are described in this paper. FULL TEXT IN SPANISH

Fusion energy division annual progress report, period ending December 31, 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1981-11-01

The ORNL Program encompasses most aspects of magnetic fusion research including research on two magnetic confinement programs (tokamaks and ELMO bumpy tori); the development of the essential technologies for plasma heating, fueling, superconducting magnets, and materials; the development of diagnostics; the development of atomic physics and radiation effect data bases; the assessment of the environmental impact of magnetic fusion; the physics and engineering of present-generation devices; and the design of future devices. The integration of all of these activities into one program is a major factor in the success of each activity. An excellent example of this integration is themore » extremely successful application of neutral injection heating systems developed at ORNL to tokamaks both in the Fusion Energy Division and at Princeton Plasma Physics Laboratory (PPPL). The goal of the ORNL Fusion Program is to maintain this balance between plasma confinement, technology, and engineering activities.« less

History from the ground up: bugs, political economy, and God in Kirby and Spence's Introduction to Entomology (1815-1856).

PubMed

Clark, J F M

2006-03-01

William Kirby and William Spence's Introduction to Entomology is generally recognized as one of the founding texts of entomological science in English. This essay examines the ideological allegiances of the coauthors of the Introduction. In particular, it analyzes the ideological implications of their divergent opinions on animal instinct. Different vocational pursuits shaped each man's natural history. Spence, a political economist, pursued fact-based science that was shorn of references to religion. Kirby, a Tory High Churchman, placed revelation at the very heart of his natural history. His strong commitment to partisan sectarianism cautions against reference to a homogeneous "natural theology" that was an agent of mediation. Fissures in the "common intellectual context" reached beyond the clash between natural theologians and radical anatomists to render the intellectual edifice of natural theology structurally less sound for the future.

AXIALLY ORIENTED SECTIONS OF NUMMULITIDS: A TOOL TO INTERPRET LARGER BENTHIC FORAMINIFERAL DEPOSITS

PubMed Central

Hohenegger, Johann; Briguglio, Antonino

2015-01-01

The “critical shear velocity” and “settling velocity” of foraminiferal shells are important parameters for determining hydrodynamic conditions during deposition of Nummulites banks. These can be estimated by determining the size, shape, and density of nummulitid shells examined in axial sections cut perpendicular to the bedding plane. Shell size and shape can be determined directly from the shell diameter and thickness, but density must be calculated indirectly from the thin section. Calculations using the half-tori method approximate shell densities by equalizing the chamber volume of each half whorl, based on the half whorl’s lumen area and its center of gravity. Results from this method yield the same lumen volumes produced empirically by micro-computed tomography. The derived hydrodynamic parameters help estimate the minimum flow velocities needed to entrain nummulitid tests and provide a potential tool to account for the nature of their accumulations. PMID:26166914

AXIALLY ORIENTED SECTIONS OF NUMMULITIDS: A TOOL TO INTERPRET LARGER BENTHIC FORAMINIFERAL DEPOSITS.

PubMed

Hohenegger, Johann; Briguglio, Antonino

2012-04-01

The "critical shear velocity" and "settling velocity" of foraminiferal shells are important parameters for determining hydrodynamic conditions during deposition of Nummulites banks. These can be estimated by determining the size, shape, and density of nummulitid shells examined in axial sections cut perpendicular to the bedding plane. Shell size and shape can be determined directly from the shell diameter and thickness, but density must be calculated indirectly from the thin section. Calculations using the half-tori method approximate shell densities by equalizing the chamber volume of each half whorl, based on the half whorl's lumen area and its center of gravity. Results from this method yield the same lumen volumes produced empirically by micro-computed tomography. The derived hydrodynamic parameters help estimate the minimum flow velocities needed to entrain nummulitid tests and provide a potential tool to account for the nature of their accumulations.

Hard X-ray tests of the unified model for an ultraviolet-detected sample of Seyfert 2 galaxies

NASA Technical Reports Server (NTRS)

Mulchaey, John S.; Myshotzky, Richard F.; Weaver, Kimberly A.

1992-01-01

An ultraviolet-detected sample of Seyfert 2 galaxies shows heavy photoelectric absorption in the hard X-ray band. The presence of UV emission combined with hard X-ray absorption argues strongly for a special geometry which must have the general properties of the Antonucci and Miller unified model. The observations of this sample are consistent with the picture in which the hard X-ray photons are viewed directly through the obscuring matter (molecular torus?) and the optical, UV, and soft X-ray continuum are seen in scattered light. The large range in X-ray column densities implies that there must be a large variation in intrinsic thicknesses of molecular tori, an assumption not found in the simplest of unified models. Furthermore, constraints based on the cosmic X-ray background suggest that some of the underlying assumptions of the unified model are wrong.

Excitation basis for (3+1)d topological phases

NASA Astrophysics Data System (ADS)

Delcamp, Clement

2017-12-01

We consider an exactly solvable model in 3+1 dimensions, based on a finite group, which is a natural generalization of Kitaev's quantum double model. The corresponding lattice Hamiltonian yields excitations located at torus-boundaries. By cutting open the three-torus, we obtain a manifold bounded by two tori which supports states satisfying a higher-dimensional version of Ocneanu's tube algebra. This defines an algebraic structure extending the Drinfel'd double. Its irreducible representations, labeled by two fluxes and one charge, characterize the torus-excitations. The tensor product of such representations is introduced in order to construct a basis for (3+1)d gauge models which relies upon the fusion of the defect excitations. This basis is defined on manifolds of the form Σ × S_1 , with Σ a two-dimensional Riemann surface. As such, our construction is closely related to dimensional reduction from (3+1)d to (2+1)d topological orders.

General Relativistic Radiative Transfer: Applications to Black-Hole Systems

NASA Technical Reports Server (NTRS)

Wu, Kinwah; Fuerst, Steven V.; Mizuno, Yosuke; Nishikawa, Ken-Ichi; Branduardi-Raymont, Graziella; Lee, Khee-Gan

2007-01-01

We present general relativistic radiation transfer formulations which include opacity effects due to absorption, emission and scattering explicitly. We consider a moment expansions for the transfer in the presence of scattering. The formulation is applied to calculation emissions from accretion and outflows in black-hole systems. Cases with thin accretion disks and accretion tori are considered. Effects, such as emission anisotropy, non-stationary flows and geometrical self-occultation are investigated. Polarisation transfer in curved space-time is discussed qualitatively.

The existence of periodic solutions for nonlinear beam equations on Td by a para-differential method

NASA Astrophysics Data System (ADS)

Chen, Bochao; Li, Yong; Gao, Yixian

2018-05-01

This paper focuses on the construction of periodic solutions of nonlinear beam equations on the $d$-dimensional tori. For a large set of frequencies, we demonstrate that an equivalent form of the nonlinear equations can be obtained by a para-differential conjugation. Given the non-resonant conditions on each finite dimensional subspaces, it is shown that the periodic solutions can be constructed for the block diagonal equation by a classical iteration scheme.

Heating and Cooling Master Plan for Fort Bragg, NC, Fiscal Years 2005 to 2030

DTIC Science & Technology

2009-02-01

Pacific Northwest National Labora- tory ( PNNL ) performed an energy use analysis on these buildings in 2005. These buildings are located in 33 specific...electrical equipment the electrical use is provided in the PNNL analysis .* The central chilled water system energy use is reported in cooling chilled...February 2009 C on st ru ct io n E n gi n ee ri n g R es ea rc h L ab or at or y Approved for public release; distribution is unlimited

Lorenz on Leadership: Lessons on Effectively Leading People, Teams, and Organizations

DTIC Science & Technology

2012-08-01

Using a combination of theory , his- tory, and field research, instructors at the school wrote the plan em- ployed by the United States in World War II...air, space, and cyber- space theory and history is small compared to the percentage of land-power experts at Army or Marine schools. At times this...that was the day I fell in love with the Academy. Con- struction on Cadet Chapel had yet to begin, and Sijan Hall was still years in the future. I

Design and Development of a Prototype Organizational Effectiveness Information System

DTIC Science & Technology

1984-11-01

information from a large number of people. The existing survey support process for the GOQ is not satisfac- * tory. Most OESOs elect not to use it, because...reporting process uses screen queries and menus to simplify data entry, it is estimated that only 4-6 hours of data entry time would be required for ...description for the file named EVEDIR. The Resource System allows users of the Event Directory to select from the following processing options. o Add a new

High-Resolution Array with Prony, MUSIC, and ESPRIT Algorithms

DTIC Science & Technology

1992-08-25

N avalI Research La bora tory AD-A255 514 Washington, DC 20375-5320 NRL/FR/5324-92-9397 High-resolution Array with Prony, music , and ESPRIT...unlimited t"orm n pprovoiREPORT DOCUMENTATION PAGE OMB. o 0 104 0188 4. TITLE AND SUBTITLE S. FUNDING NUMBERS High-resolution Array with Prony. MUSIC . and...the array high-resolution properties of three algorithms: the Prony algo- rithm, the MUSIC algorithm, and the ESPRIT algorithm. MUSIC has been much

Toroidal marginally outer trapped surfaces in closed Friedmann-Lemaître-Robertson-Walker spacetimes: Stability and isoperimetric inequalities

NASA Astrophysics Data System (ADS)

Mach, Patryk; Xie, Naqing

2017-10-01

We investigate toroidal marginally outer trapped surfaces (MOTS) and marginally outer trapped tubes (MOTT) in closed Friedmann-Lemaître-Robertson-Walker (FLRW) geometries. They are constructed by embedding constant mean curvature (CMC) Clifford tori in a FLRW spacetime. This construction is used to assess the quality of certain isoperimetric inequalities, recently proved in axial symmetry. Similarly to spherically symmetric MOTS existing in FLRW spacetimes, the toroidal ones are also unstable.

Middle East Security Issues: In the Shadow of Weapons of Mass Destruction Proliferation

DTIC Science & Technology

1999-12-01

same t ime, Iran’s confrontation with Afghanistan pits a Shi’ite religious regime against a much more extreme Tal i- ban reg ime in Afghanistan...I ran has increasingly suppl ied arms and aid to the opposi t ion to the Tal iban, and deployed several hundred thousand t roops for exercises...rapidly deploy a few combat strength bat tal ions to defend i ts terr i tory, and Saudi Arabia would take days to deploy even one heavy brigade into

Causal Factors in Alcohol Rehabilitation Success or Failure.

DTIC Science & Technology

1980-03-01

items was administered routinely to all rehabilitation partici- pants and provided a wide range of information on family and social background...information pertaining to family background, social and occupational his- tory, military service, and drinking history and alcohol-related problems. At the...84 30 73.7 113 21 84.3 Total 939 143 585 82 707 73 A X 2 = 12.16; df = 2; p < .01 26.51; 2; p < .001 14.65; 2; p < .001ik Age Alcohol Problema 17, 28

Reshaping the All-Volunteer Force of the United States to Increase its Utility: A Reassessment of Over Forty Years of Experience

DTIC Science & Technology

2015-05-23

War] and the long campaign to ‘settle’ the Indian problem on the frontier.” Richard W. Stewart , ed., American Military His- tory Volume 1: The United...144. 6 Ibid., 167. 7 Stewart , ed., American Military History Volume I, 17. 5 structure that allowed for quick expansion. “This marked the...11 Stewart , ed., American Military History Volume 1, 304. 12 Ibid., 312. 13 Huntington, 161. The origins

Strategic Implications of Moscow’s Concept for Collective Security in Asia

DTIC Science & Technology

1976-06-11

social liberation to this end . . . [Whereas] the Americans dream of an agreement between the two. The Soviet leaders declare a reconciliation to be...at a time when the balance of . . . forces in the world is* changing as a result of new major vic- tories on the part of world socialism and a...17 that a serious change had occurred in the relation of forces between the countries of socialism and capitalism in favor of the socialist nations

Cancer Incidence in the U.S. Military Population: Comparison with Rates from the SEER Program

DTIC Science & Technology

2009-06-08

reproductive his- tory such as age at first birth, parity, and use of contracep- tives. Military women may be more likely to use oral contraceptive ...analysis, 34% of active-duty women and 29% of women in the general population used oral contraceptive pills in the preceding 12 months. Oral... contraceptive pill use has been shown to increase the risk for breast cancer, particu- larly in younger women (33, 34). Military women are also more likely to

The Coast Artillery Journal. Volume 79, Number 6, November-December 1936

DTIC Science & Technology

1936-12-01

news from the enveloping right wing toward which all Schlieffen-trained staff officers looked for vic - tory. OHL-Kaiser, staff officers, civil and...many of its means of defense as possible. 1936 ~ _ PROVISIONS OF DIRECTIVE OF AUGUST 27 _- - THE EXECUTION SCALE o 5 10 20 3{) THE WILL OF THE LEADER...the Oise and that only weak rear guards were in front of his right. On the 29th he would attack the fortress of La Fere. This report could mean only one

Orbital Tori Construction Using Trajectory Following Spectral Methods

DTIC Science & Technology

2010-09-01

a Walker delta pattern scheme of 18/6/2. Explicitly, this means the 18 satellites were equally spaced in six planes , each inclined at 55 degrees, with...a relative phasing angle parameter of 2 [65]. The planes ’ inclinations were reduced from the original specification of 63 degrees to 55 degrees due...navigation performance specification for the SPS was ≤ 100 meters 8 in the horizontal plane , 95 percent of the time and ≤ 156 meters in the vertical plane

Definition of the Cellular Mechanisms which Distinguish Between Estrogen Receptor Agonists and Antagonists

DTIC Science & Technology

2001-07-01

hormones: 10-7 M 17p3- estradiol for ERa and ERI3, 10-7 M progesterone for PR-A and PR-B, 10-7 M dexamethasone for GR, 10-7 M 5ot-dihydrotestosterone...cyproterone acetate, d-Ald.: d-aldosterone, DHEA: dehydroepiandrosterone, DOC: 11-deoxycorticosterone, Dex: dexamethasone, MPA: medroxyprogesterone , OH-F...two receptors are not functionally equivalent and that tory activities by altering ER structure and indepen- each subtype plays a unique role in ER

Warmly Argued: A Brief Historical Look at Two Centuries of Climate Change Findings in Public Dialogue

DTIC Science & Technology

2016-10-24

scientific and scholarly sources, the article offers a short examination of recurrent themes in the history of public and scientific dia- logue concerning... history , climate science history , global warming his- tory, public opinion and climate change In 1957 when historian A. Hunter Dupree wrote, “In a narrow...the time. That’s what the military does. Michael Reis is a senior vice president at History Associates Inc., a historical services firm in Rockville

Nada: A new code for studying self-gravitating tori around black holes

NASA Astrophysics Data System (ADS)

Montero, Pedro J.; Font, José A.; Shibata, Masaru

2008-09-01

We present a new two-dimensional numerical code called Nada designed to solve the full Einstein equations coupled to the general relativistic hydrodynamics equations. The code is mainly intended for studies of self-gravitating accretion disks (or tori) around black holes, although it is also suitable for regular spacetimes. Concerning technical aspects the Einstein equations are formulated and solved in the code using a formulation of the standard 3+1 Arnowitt-Deser-Misner canonical formalism system, the so-called Baumgarte-Shapiro Shibata-Nakamura approach. A key feature of the code is that derivative terms in the spacetime evolution equations are computed using a fourth-order centered finite difference approximation in conjunction with the Cartoon method to impose the axisymmetry condition under Cartesian coordinates (the choice in Nada), and the puncture/moving puncture approach to carry out black hole evolutions. Correspondingly, the general relativistic hydrodynamics equations are written in flux-conservative form and solved with high-resolution, shock-capturing schemes. We perform and discuss a number of tests to assess the accuracy and expected convergence of the code, namely, (single) black hole evolutions, shock tubes, and evolutions of both spherical and rotating relativistic stars in equilibrium, the gravitational collapse of a spherical relativistic star leading to the formation of a black hole. In addition, paving the way for specific applications of the code, we also present results from fully general relativistic numerical simulations of a system formed by a black hole surrounded by a self-gravitating torus in equilibrium.

Dissipative Quantum Mechanics and Kondo-Like Impurities on Noncommutative Two-Tori

NASA Astrophysics Data System (ADS)

Iacomino, Patrizia; Marotta, Vincenzo; Naddeo, Adele

In a recent paper, by exploiting the notion of Morita equivalence for field theories on noncommutative tori and choosing rational values of the noncommutativity parameter θ (in appropriate units), a general one-to-one correspondence between the m-reduced conformal field theory (CFT) describing a quantum Hall fluid (QHF) at paired states fillings1,2 ν = (m)/(pm+2) and an Abelian noncommutative field theory (NCFT) has been established.3 That allowed us to add new evidence to the relationship between noncommutativity and quantum Hall fluids.4 On the other hand, the m-reduced CFT is equivalent to a system of two massless scalar bosons with a magnetic boundary interaction as introduced in Ref. 5, at the so-called "magic" points. We are then able to describe, within such a framework, the dissipative quantum mechanics of a particle confined to a plane and subject to an external magnetic field normal to it. Here we develop such a point of view by focusing on the case m=2 which corresponds to a quantum Hall bilayer. The key role of a localized impurity which couples the two layers is emphasized and the effect of noncommutativity in terms of generalized magnetic translations (GMT) is fully exploited. As a result, general GMT operators are introduced, in the form of a tensor product, which act on the QHF and defect space respectively, and a comprehensive study of their rich structure is performed.

New insights into the mechanisms of water-stress-induced cavitation in conifers.

PubMed

Cochard, Hervé; Hölttä, Teemu; Herbette, Stéphane; Delzon, Sylvain; Mencuccini, Maurizio

2009-10-01

Cavitation resistance is a key parameter to understand tree drought tolerance but little is known about the mechanisms of air entry into xylem conduits. For conifers three mechanisms have been proposed: (1) a rupture of pit margo microfibrils, (2) a displacement of the pit torus from its normal sealing position over the pit aperture, and (3) a rupture of an air-water menisci in a pore of the pit margo. In this article, we report experimental results on three coniferous species suggesting additional mechanisms. First, when xylem segments were injected with a fluid at a pressure sufficient to aspirate pit tori and well above the pressure for cavitation induction we failed to detect the increase in sample conductance that should have been caused by torus displacement from blocking the pit aperture or by membrane rupture. Second, by injecting xylem samples with different surfactant solutions, we found a linear relation between sample vulnerability to cavitation and fluid surface tension. This suggests that cavitation in conifers could also be provoked by the capillary failure of an air-water meniscus in coherence with the prediction of Young-Laplace's equation. Within the bordered pit membrane, the exact position of this capillary seeding is unknown. The possible Achilles' heel could be the seal between tori and pit walls or holes in the torus. The mechanism of water-stress-induced cavitation in conifers could then be relatively similar to the one currently proposed for angiosperms.

Hovsgol earthquake 5 December 2014, M W = 4.9: seismic and acoustic effects

NASA Astrophysics Data System (ADS)

Dobrynina, Anna A.; Sankov, Vladimir A.; Tcydypova, Larisa R.; German, Victor I.; Chechelnitsky, Vladimir V.; Ulzibat, Munkhuu

2018-03-01

A moderate shallow earthquake occurred on 5 December 2014 ( M W = 4.9) in the north of Lake Hovsgol (northern Mongolia). The infrasonic signal with duration 140 s was recorded for this earthquake by the "Tory" infrasound array (Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Science, Russia). Source parameters of the earthquake (seismic moment, geometrical sizes, displacement amplitudes in the focus) were determined using spectral analysis of direct body P and S waves. The spectral analysis of seismograms and amplitude variations of the surface waves allows to determine the effect of the propagation of the rupture in the earthquake focus, the azimuth of the rupture propagation direction and the velocity of displacement in the earthquake focus. The results of modelling of the surface displacements caused by the Hovsgol earthquake and high effective velocity of propagation of infrasound signal ( 625 m/s) indicate that its occurrence is not caused by the downward movement of the Earth's surface in the epicentral region but by the effect of the secondary source. The position of the secondary source of infrasound signal is defined on the northern slopes of the Khamar-Daban ridge according to the data on the azimuth and time of arrival of acoustic wave at the Tory station. The interaction of surface waves with the regional topography is proposed as the most probable mechanism of formation of the infrasound signal.

Poloidal and toroidal plasmons and fields of multilayer nanorings

DOE PAGES

Garapati, K. V.; Salhi, M.; Kouchekian, S.; ...

2017-04-17

Composite and janus type metallodielectric nanoparticles are increasingly considered as a means to control the spatial and temporal behavior of electromagnetic fields in diverse applications such as coupling to quantum emitters, achieving invisibility cloaks, and obtaining quantum correlations between qubits. We investigate the surface modes of a toroidal nanostructure and obtain the canonical plasmon dispersion relations and resonance modes for arbitrarily layered nanorings. Unlike particle plasmon eigenmodes in other geometries, the amplitudes of the eigenmodes of tori exhibit a distinct forward and backward coupling. We present the plasmon dispersion relations for several relevant toroidal configurations in the quasistatic limit andmore » obtain the dominant retarded dispersion relations of a single ring for comparison, discuss mode complementarity and hybridization, and introduce two new types of toroidal particles in the form of janus nanorings. The resonance frequencies for the first few dominant modes of a ring composed of plasmon supporting materials such as gold, silver, and aluminum are provided and compared to those for a silicon ring. A generalized Green's function is obtained for multilayer tori allowing for calculation of the scattering response to interacting fields. Employing the Green's function, the scalar electric potential distribution corresponding to individual poloidal and toroidal modes in response to an arbitrarily polarized external field and the field of electrons is obtained. The results are applied to obtain the local density of states and decay rate of a dipole near the center of the torus.« less

Investigating multiphoton phenomena using nonlinear dynamics

NASA Astrophysics Data System (ADS)

Huang, Shu

Many seemingly simple systems can display extraordinarily complex dynamics which has been studied and uncovered through nonlinear dynamical theory. The leitmotif of this thesis is changing phase-space structures and their (linear or non-linear) stabilities by adding control functions (which act on the system as external perturbations) to the relevant Hamiltonians. These phase-space structures may be periodic orbits, invariant tori or their stable and unstable manifolds. One-electron systems and diatomic molecules are fundamental and important staging ground for new discoveries in nonlinear dynamics. In past years, increasing emphasis and effort has been put on the control or manipulation of these systems. Recent developments of nonlinear dynamical tools can provide efficient ways of doing so. In the first subtopic of the thesis, we are adding a control function to restore tori at prescribed locations in phase space. In the remainder of the thesis, a control function with parameters is used to change the linear stability of the periodic orbits which govern the processes in question. In this thesis, we report our theoretical analyses on multiphoton ionization of Rydberg atoms exposed to strong microwave fields and the dissociation of diatomic molecules exposed to bichromatic lasers using nonlinear dynamical tools. This thesis is composed of three subtopics. In the first subtopic, we employ local control theory to reduce the stochastic ionization of hydrogen atom in a strong microwave field by adding a relatively small control term to the original Hamiltonian. In the second subtopic, we perform periodic orbit analysis to investigate multiphoton ionization driven by a bichromatic microwave field. Our results show quantitative and qualitative agreement with previous studies, and hence identify the mechanism through which short periodic orbits organize the dynamics in multiphoton ionization. In addition, we achieve substantial time savings with this approach. In the third subtopic we extend our periodic orbit analysis to the dissociation of diatomic molecules driven by a bichromatic laser. In this problem, our results based on periodic orbit analysis again show good agreement with previous work, and hence promise more potential applications of this approach in molecular physics.

Proceedings of the Pacific Conference on Operations Research, Held April 23-28, 1979, Seoul, Korea. Volume 2

DTIC Science & Technology

1979-04-01

and wa rgame s tori the ana ly t ical tools of the TRAI)OC c ommun i ty are shiown in Table 4. ’TABLE 4 SCENARIO DEVELOPMENT AND PLAY TINE DEVELOP...TO TOURISM * W. W. SWART TURCUT VAR CHARLES E. GEARING ABSRrCr. This paper categorizes the application of Operations Research to Tourism as falling...into the areas of tourist forecasting, the determination of tourist flows, the measurement and evaluation of the impact of tourism oriented facilities

Accretion tori and cones of ionizing radiation in Seyfert galaxies

NASA Technical Reports Server (NTRS)

Acosta-Pulido, Jose A.; Perez-Fournon, Ismael; Calvani, Massimo; Wilson, Andrew S.

1990-01-01

The photoionization of extended narrow-line regions in Seyfert galaxies by the radiation produced in a thick accretion disk is studied. The emission-line spectrum is calculated for a range of black hole masses, varying the values of the ionization parameter and the disk size. It is found that models with a million solar masses fit observations of very large accretion disk sizes, while models with 10 million solar masses fit them better with smaller disks. The latter models are preferable since they have lower super-Eddington accretion rates.

Chaotic dynamics in accelerator physics

NASA Astrophysics Data System (ADS)

Cary, J. R.

1992-11-01

Substantial progress was made in several areas of accelerator dynamics. We have completed a design of an FEL wiggler with adiabatic trapping and detrapping sections to develop an understanding of longitudinal adiabatic dynamics and to create efficiency enhancements for recirculating free-electron lasers. We developed a computer code for analyzing the critical KAM tori that binds the dynamic aperture in circular machines. Studies of modes that arise due to the interaction of coating beams with a narrow-spectrum impedance have begun. During this research educational and research ties with the accelerator community at large have been strengthened.

TNF-alpha Expression Patterns as Potential Molecular Biomarker for Human Skin Cells Exposed to Vesicant Chemical Warfare Agents: Sulfur Mustard (HD) and Lewisite (L)

DTIC Science & Technology

2004-01-01

First World War. It was Sabourin et al., 2000). Skin injuries caused by called Hun Stoffe by the Allies and given the HD are complex and involve... Sabourin et al., 2000, Kan et al., 2003) sup- port the involvement of TNF-cx in animal models such as mouse skin and hairless guinea References pigs... Sabourin CLK. Petrali JP. Casillas RP. Alteration in inflamma- Pharmacol Toxicol. 2003:92:20 4 -13. tory cytokine gene expression in sulfur mustard exposed

Lithium synthesis in microquasar accretion.

PubMed

Iocco, Fabio; Pato, Miguel

2012-07-13

We study the synthesis of lithium isotopes in the hot tori formed around stellar mass black holes by accretion of the companion star. We find that sizable amounts of both stable isotopes 6Li and 7Li can be produced, the exact figures varying with the characteristics of the torus and reaching as much as 10(-2) M⊙ for each isotope. This mass output is enough to contaminate the entire Galaxy at a level comparable with the original, pregalactic amount of lithium and to overcome other sources such as cosmic-ray spallation or stellar nucleosynthesis.

CAESAR: Commissioned Assignments Executive Support for the US Army.

DTIC Science & Technology

1986-03-27

travel between jobs ? b. Detailed Narrative The documented source code of CAESAR can be found in Appendix B. An explanatory listing of variables used is...Compute Match Preference PREFFORM SSI index a, b a,b Match Match Leave ADSPEC SC2 and Travel a, b Time ab a , b ~~N4 4. ORB Mac Matyh ,. ac ASI ASI SReport...sufficient time between assignments for the officer to 44 take 30 days leave and travel . While this is not a manda- tory consideration, it is common to

Lighthouse in the dust: infrared echoes of periodic emission from massive black hole binaries★

NASA Astrophysics Data System (ADS)

D'Orazio, Daniel J.; Haiman, Zoltán

2017-09-01

The optical and UV emission from sub-parsec massive black hole binaries (MBHBs) in active galactic nuclei (AGNs) is believed to vary periodically, on time-scales comparable to the binary's orbital time. If driven by accretion rate fluctuations, the variability could be isotropic. If dominated by relativistic Doppler modulation, the variability should instead be anisotropic, resembling a rotating forward-beamed lighthouse. We consider the infrared (IR) reverberation of either type of periodic emission by pc-scale circumbinary dust tori. We predict the phase and amplitude of IR variability as a function of the ratio of dust light crossing time to the source variability period, and of the torus inclination and opening angle. We enumerate several differences between the isotropic and anisotropic cases. Interestingly, for a nearly face-on binary with an inclined dust torus, the Doppler boost can produce IR variability without any observable optical/UV variability. Such orphan-IR variability would have been missed in optical searches for periodic AGNs. We apply our models to time-domain WISE IR data from the MBHB candidate PG 1302-102 and find consistency with dust reverberation by both isotropically emitting and Doppler-boosted sources in the shorter wavelength W1-W2 (2.8 → 5.3 μm) bands. We constrain the dust torus to be thin (aspect ratio ˜ 0.1), with an inner radius at 1-5 pc. More generally, our dust-echo models will aid in identifying new MBHB candidates, determining their nature and constraining the physical properties of MBHBs and their dust tori.

Complex Chern-Simons Theory at Level k via the 3d-3d Correspondence

NASA Astrophysics Data System (ADS)

Dimofte, Tudor

2015-10-01

We use the 3d-3d correspondence together with the DGG construction of theories T n [ M] labelled by 3-manifolds M to define a non-perturbative state-integral model for Chern-Simons theory at any level k, based on ideal triangulations. The resulting partition functions generalize a widely studied k = 1 state-integral, as well as the 3d index, which is k = 0. The Chern-Simons partition functions correspond to partition functions of T n [ M] on squashed lens spaces L( k, 1). At any k, they admit a holomorphic-antiholomorphic factorization, corresponding to the decomposition of L( k, 1) into two solid tori, and the associated holomorphic block decomposition of the partition functions of T n [ M]. A generalization to L( k, p) is also presented. Convergence of the state integrals, for any k, requires triangulations to admit a positive angle structure; we propose that this is also necessary for the DGG gauge theory T n [ M] to flow to a desired IR SCFT.

Magnetic Control of Locked Modes in Present Devices and ITER

NASA Astrophysics Data System (ADS)

Volpe, F. A.; Sabbagh, S.; Sweeney, R.; Hender, T.; Kirk, A.; La Haye, R. J.; Strait, E. J.; Ding, Y. H.; Rao, B.; Fietz, S.; Maraschek, M.; Frassinetti, L.; in, Y.; Jeon, Y.; Sakakihara, S.

2014-10-01

The toroidal phase of non-rotating (``locked'') neoclassical tearing modes was controlled in several devices by means of applied magnetic perturbations. Evidence is presented from various tokamaks (ASDEX Upgrade, DIII-D, JET, J-TEXT, KSTAR), spherical tori (MAST, NSTX) and a reversed field pinch (EXTRAP-T2R). Furthermore, the phase of interchange modes was controlled in the LHD helical device. These results share a common interpretation in terms of torques acting on the mode. Based on this interpretation, it is predicted that control-coil currents will be sufficient to control the phase of locking in ITER. This will be possible both with the internal coils and with the external error-field-correction coils, and might have promising consequences for disruption avoidance (by aiding the electron cyclotron current drive stabilization of locked modes), as well as for spatially distributing heat loads during disruptions. This work was supported in part by the US Department of Energy under DE-SC0008520, DE-FC-02-04ER54698 and DE-AC02-09CH11466.

A hybrid multiview stereo algorithm for modeling urban scenes.

PubMed

Lafarge, Florent; Keriven, Renaud; Brédif, Mathieu; Vu, Hoang-Hiep

2013-01-01

We present an original multiview stereo reconstruction algorithm which allows the 3D-modeling of urban scenes as a combination of meshes and geometric primitives. The method provides a compact model while preserving details: Irregular elements such as statues and ornaments are described by meshes, whereas regular structures such as columns and walls are described by primitives (planes, spheres, cylinders, cones, and tori). We adopt a two-step strategy consisting first in segmenting the initial meshbased surface using a multilabel Markov Random Field-based model and second in sampling primitive and mesh components simultaneously on the obtained partition by a Jump-Diffusion process. The quality of a reconstruction is measured by a multi-object energy model which takes into account both photo-consistency and semantic considerations (i.e., geometry and shape layout). The segmentation and sampling steps are embedded into an iterative refinement procedure which provides an increasingly accurate hybrid representation. Experimental results on complex urban structures and large scenes are presented and compared to state-of-the-art multiview stereo meshing algorithms.

Chaos in a restricted problem of rotation of a rigid body with a fixed point

NASA Astrophysics Data System (ADS)

Borisov, A. V.; Kilin, A. A.; Mamaev, I. S.

2008-06-01

In this paper, we consider the transition to chaos in the phase portrait of a restricted problem of rotation of a rigid body with a fixed point. Two interrelated mechanisms responsible for chaotization are indicated: (1) the growth of the homoclinic structure and (2) the development of cascades of period doubling bifurcations. On the zero level of the area integral, an adiabatic behavior of the system (as the energy tends to zero) is noted. Meander tori induced by the break of the torsion property of the mapping are found.

Combat Modeling Evaluation at the United States Military Academy.

DTIC Science & Technology

1985-06-01

Ti.s to a smil- ique eitew de = Smaleissei by doe S hefer Press. am rnr we ma@"e- even I - "-re is hso use mom a sly ente orders bring dartani, vphae... transported to the VIIA *yet= at MR., a proes* which to almeet complete. 2Me lepertmet of fts- tory will thee be able te evelse the Sharks, md Arfemme...danewa its we modified As mei mmr Ciaur. 6). &W mit thot sooogltoly esm~hts Its supply of inmoitIawl"q eoat is Smoediaboly de . ttopd. IM6 OSOMe WOW. U

Effects of two successive parity-invariant point interactions on one-dimensional quantum transmission: Resonance conditions for the parameter space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konno, Kohkichi, E-mail: kohkichi@tomakomai-ct.ac.jp; Nagasawa, Tomoaki, E-mail: nagasawa@tomakomai-ct.ac.jp; Takahashi, Rohta, E-mail: takahashi@tomakomai-ct.ac.jp

We consider the scattering of a quantum particle by two independent, successive parity-invariant point interactions in one dimension. The parameter space for the two point interactions is given by the direct product of two tori, which is described by four parameters. By investigating the effects of the two point interactions on the transmission probability of plane wave, we obtain the conditions for the parameter space under which perfect resonant transmission occur. The resonance conditions are found to be described by symmetric and anti-symmetric relations between the parameters.

Evaluation of the Efficacy of Modified Vaccinia Ankara (MVA)/IMVAMUNE (registered trademark) Against Aerosolized Rabbitpox Virus in a Rabbit Model

DTIC Science & Technology

2009-01-01

eczema accinatum and progressive vaccinia in individuals such as eczema ufferers and the immunocompromised, caused concerns about the accine and prompted...aerosolized RPXV under conditions as previously described [13]. Briefly, the respira- tory function of each rabbit was first measured using whole-body...using respiratory minute volume (Vm) estimates derived from the respiratory function mea- 5 cine 2 s d e o f 2 m p 2 s o c b a w a k w 2 o s t s b s w t

SMP: A solid modeling program version 2.0

NASA Technical Reports Server (NTRS)

Randall, D. P.; Jones, K. H.; Vonofenheim, W. H.; Gates, R. L.; Matthews, C. G.

1986-01-01

The Solid Modeling Program (SMP) provides the capability to model complex solid objects through the composition of primitive geometric entities. In addition to the construction of solid models, SMP has extensive facilities for model editing, display, and analysis. The geometric model produced by the software system can be output in a format compatible with existing analysis programs such as PATRAN-G. The present version of the SMP software supports six primitives: boxes, cones, spheres, paraboloids, tori, and trusses. The details for creating each of the major primitive types is presented. The analysis capabilities of SMP, including interfaces to existing analysis programs, are discussed.

Ergodicity of a singly-thermostated harmonic oscillator

NASA Astrophysics Data System (ADS)

Hoover, William Graham; Sprott, Julien Clinton; Hoover, Carol Griswold

2016-03-01

Although Nosé's thermostated mechanics is formally consistent with Gibbs' canonical ensemble, the thermostated Nosé-Hoover (harmonic) oscillator, with its mean kinetic temperature controlled, is far from ergodic. Much of its phase space is occupied by regular conservative tori. Oscillator ergodicity has previously been achieved by controlling two oscillator moments with two thermostat variables. Here we use computerized searches in conjunction with visualization to find singly-thermostated motion equations for the oscillator which are consistent with Gibbs' canonical distribution. Such models are the simplest able to bridge the gap between Gibbs' statistical ensembles and Newtonian single-particle dynamics.

A Benchmark Study of the Air Force Program Executive Office for Combat and Mission Support

DTIC Science & Technology

2011-10-05

Capt. Finkenstadt graduated from Mt. Olive College in Mt. Olive, NC, with a degree in business management and earned the Laura W. and Maurice H. King ...POC: See king SILVER S1a1u s Protest His tory • .so..n• Sekelon a ProtHI: • Con.eenAdon • S:UIItllln-.d ~d ~ ffi I • I -FYO& I’YQe 0 ll$ ... 2...more consecutive years at a Green Rating - Incentive/Award Fee decisions c lear ly t ied to perfonnance - No violations of bona fide need rule

Integrability and structural stability of solutions to the Ginzburg-Landau equation

NASA Technical Reports Server (NTRS)

Keefe, Laurence R.

1986-01-01

The integrability of the Ginzburg-Landau equation is studied to investigate if the existence of chaotic solutions found numerically could have been predicted a priori. The equation is shown not to possess the Painleveproperty, except for a special case of the coefficients that corresponds to the integrable, nonlinear Schroedinger (NLS) equation. Regarding the Ginzburg-Landau equation as a dissipative perturbation of the NLS, numerical experiments show all but one of a family of two-tori solutions, possessed by the NLS under particular conditions, to disappear under real perturbations to the NLS coefficients of O(10 to the -6th).

Inductance Calculations of Variable Pitch Helical Inductors

DTIC Science & Technology

2015-08-01

8217 ’ Integral solution using Simpson’s Rule ’ Dim i As Integer Dim Pi As Double, uo As Double, kc As Double Dim a As Double, amax As Double, da As...Double Dim steps As Integer Dim func1a As Double, func1b As Double ’ On Error GoTo err_TorisV1 steps = 1000 Pi = 3.14159 uo = 4 * Pi * 0.0000001...As Double ’ ’ Integral solution using Simpson’s Rule ’ Dim i As Integer Dim Pi As Double, uo As Double, kc As Double Dim a As Double, amax As

Parameterization of typhoon-induced ocean cooling using temperature equation and machine learning algorithms: an example of typhoon Soulik (2013)

NASA Astrophysics Data System (ADS)

Wei, Jun; Jiang, Guo-Qing; Liu, Xin

2017-09-01

This study proposed three algorithms that can potentially be used to provide sea surface temperature (SST) conditions for typhoon prediction models. Different from traditional data assimilation approaches, which provide prescribed initial/boundary conditions, our proposed algorithms aim to resolve a flow-dependent SST feedback between growing typhoons and oceans in the future time. Two of these algorithms are based on linear temperature equations (TE-based), and the other is based on an innovative technique involving machine learning (ML-based). The algorithms are then implemented into a Weather Research and Forecasting model for the simulation of typhoon to assess their effectiveness, and the results show significant improvement in simulated storm intensities by including ocean cooling feedback. The TE-based algorithm I considers wind-induced ocean vertical mixing and upwelling processes only, and thus obtained a synoptic and relatively smooth sea surface temperature cooling. The TE-based algorithm II incorporates not only typhoon winds but also ocean information, and thus resolves more cooling features. The ML-based algorithm is based on a neural network, consisting of multiple layers of input variables and neurons, and produces the best estimate of the cooling structure, in terms of its amplitude and position. Sensitivity analysis indicated that the typhoon-induced ocean cooling is a nonlinear process involving interactions of multiple atmospheric and oceanic variables. Therefore, with an appropriate selection of input variables and neuron sizes, the ML-based algorithm appears to be more efficient in prognosing the typhoon-induced ocean cooling and in predicting typhoon intensity than those algorithms based on linear regression methods.

Software framework for prognostic health monitoring of ocean-based power generation

NASA Astrophysics Data System (ADS)

Bowren, Mark

On August 5, 2010 the U.S. Department of Energy (DOE) has designated the Center for Ocean Energy Technology (COET) at Florida Atlantic University (FAU) as a national center for ocean energy research and development of prototypes for open-ocean power generation. Maintenance on ocean-based machinery can be very costly. To avoid unnecessary maintenance it is necessary to monitor the condition of each machine in order to predict problems. This kind of prognostic health monitoring (PHM) requires a condition-based maintenance (CBM) system that supports diagnostic and prognostic analysis of large amounts of data. Research in this field led to the creation of ISO13374 and the development of a standard open-architecture for machine condition monitoring. This thesis explores an implementation of such a system for ocean-based machinery using this framework and current open-standard technologies.

Real-time generation of infrared ocean scene based on GPU

NASA Astrophysics Data System (ADS)

Jiang, Zhaoyi; Wang, Xun; Lin, Yun; Jin, Jianqiu

2007-12-01

Infrared (IR) image synthesis for ocean scene has become more and more important nowadays, especially for remote sensing and military application. Although a number of works present ready-to-use simulations, those techniques cover only a few possible ways of water interacting with the environment. And the detail calculation of ocean temperature is rarely considered by previous investigators. With the advance of programmable features of graphic card, many algorithms previously limited to offline processing have become feasible for real-time usage. In this paper, we propose an efficient algorithm for real-time rendering of infrared ocean scene using the newest features of programmable graphics processors (GPU). It differs from previous works in three aspects: adaptive GPU-based ocean surface tessellation, sophisticated balance equation of thermal balance for ocean surface, and GPU-based rendering for infrared ocean scene. Finally some results of infrared image are shown, which are in good accordance with real images.

Flux amplification in helicity injected spherical tori

NASA Astrophysics Data System (ADS)

Tang, X. Z.; Boozer, A. H.

2005-04-01

An important measure of the effective current drive by helicity injection into spheromaks and spherical tori is provided by the flux amplification factor, defined as the ratio between the closed poloidal flux in the relaxed mean field and the initial injector vacuum poloidal flux. Flux amplification in magnetic helicity injection is governed by a resonant behavior for Taylor-relaxed plasmas satisfying j =kB. Under the finite net toroidal flux constraint in a spherical torus (ST), the constrained linear resonance k1c is upshifted substantially from the primary Jensen-Chu resonance k1 that was known to be responsible for flux amplification in spheromak formation. Standard coaxial helicity injection into a ST operates at large M, with M the characteristic dimensionless parameter defined as the ratio between the toroidal flux in the discharge chamber and the injector poloidal flux. Meaningful flux amplification for ST plasmas is limited by a critical kr at which edge toroidal field reverses its direction. The kr is downshifted from k1 by a small amount inversely proportional to M. The maximum flux amplification factor Ar≡A(k=kr) scales linearly with M. At the other end of k, substantial flux amplification A(k =ko)˜1 becomes available for ko that scales inversely proportional to M, a significant departure from that in spheromak formation. These important parameters follow the inequality ko

Diagnosing the Kinematics of the Tori in Active Galactic Nuclei with the Velocity-resolved Reverberation Mapping of the Narrow Iron K α Line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Yuan; Li Xiaobo, E-mail: liuyuan@ihep.ac.cn, E-mail: lixb@ihep.ac.cn

The properties of the dusty tori in active galactic nuclei (AGNs) have been investigated in detail, mainly focusing on the geometry and components; however, the kinematics of the torus are still not clear. The narrow iron K α line at 6.4 keV is thought to be produced by the X-ray reflection from the torus. Thus, the velocity-resolved reverberation mapping of it is able to constrain the kinematics of the torus. Such effort is limited by the spectral resolution of current charged coupled device (CCD) detectors and should be possible with the microcalorimeter on the next generation X-ray satellite. In thismore » paper, we first construct the response functions of the torus under a uniform inflow, a Keplerian rotation, and a uniform outflow. Then the energy-dependent light curve of the narrow iron K α line is simulated according to the performance of the X-ray Integral Field Unit in Athena. Finally, the energy-dependent cross-correlation function is calculated to reveal the kinematic signal. According to our results, 100 observations with 5 ks exposure of each are sufficient to distinguish the above three velocity fields. Although the real geometry and velocity field of the torus could be more complex than we assumed, the present result proves the feasibility of the velocity-resolved reverberation mapping of the narrow iron K α line. The combination of the dynamics of the torus with those of the broad-line region and the host galaxy is instructive for the understanding of the feeding and feedback process of AGNs.« less

First X-ray Statistical Tests for Clumpy Torii Models: Constraints from RXTE monitoring of Seyfert AGN

NASA Astrophysics Data System (ADS)

Markowitz, A.

2015-09-01

We summarize two papers providing the first X-ray-derived statistical constraints for both clumpy-torus model parameters and cloud ensemble properties. In Markowitz, Krumpe, & Nikutta (2014), we explored multi-timescale variability in line-of-sight X-ray absorbing gas as a function of optical classification. We examined 55 Seyferts monitored with the Rossi X-ray Timing Explorer, and found in 8 objects a total of 12 eclipses, with durations between hours and years. Most clouds are commensurate with the outer portions of the BLR, or the inner regions of infrared-emitting dusty tori. The detection of eclipses in type Is disfavors sharp-edged tori. We provide probabilities to observe a source undergoing an absorption event for both type Is and IIs, yielding constraints in [N_0, sigma, i] parameter space. In Nikutta et al., in prep., we infer that the small cloud angular sizes, as seen from the SMBH, imply the presence of >10^7 clouds in BLR+torus to explain observed covering factors. Cloud size is roughly proportional to distance from the SMBH, hinting at the formation processes (e.g. disk fragmentation). All observed clouds are sub-critical with respect to tidal disruption; self-gravity alone cannot contain them. External forces (e.g. magnetic fields, ambient pressure) are needed to contain them, or otherwise the clouds must be short-lived. Finally, we infer that the radial cloud density distribution behaves as 1/r^{0.7}, compatible with VLTI observations. Our results span both dusty and non-dusty clumpy media, and probe model parameter space complementary to that for short-term eclipses observed with XMM-Newton, Suzaku, and Chandra.

Seabird bycatch mitigation trials in artisanal demersal longliners of the Western Mediterranean.

PubMed

Cortés, Verónica; González-Solís, Jacob

2018-01-01

High numbers of seabirds are killed annually worldwide in longline fisheries. In the Mediterranean, this mortality is seriously affecting the viability of seabird populations, in particular of the three endemic shearwaters. Even so, there is currently no specific seabird mitigation requirements for the longline fleet operating in this area. From 2013 to 2014, we assessed the efficiency and practical applicability of four mitigation measures on artisanal demersal longliners targeting European hake (Merluccius merluccius) in the western Mediterranean: night setting, tori line, weighted lines and artificial baits. We performed fifty-two pairs of experimental (with the tested mitigation measure) and control settings (without any measure), and compared their effects on seabird interactions and fish catches. In addition, we estimated the longline sink rates and the seabird access area to baited hooks in different longline configurations. Night setting reduced bycatch risk without affecting target and non-commercial fish catches. The tori line may have reduced the bycatch risk by displacing bait attacks beyond the end of the line, but at this distance shearwaters could still access to the baits and the streamers did not deter birds under calm wind conditions. Weighted lines increased sink rate, but it resulted in only a minor reduction of the seabird access window to baited hooks and led to some operational problems during the setting. Artificial baits substantially reduced commercial catches. Moreover, the seabird access to the baited hooks was influenced by the longline configuration, the setting speed and the relative position to the floats and weights. So far, night setting stands out as the best mitigation measure for reducing bycatch levels without compromising target catches in demersal longliners. Ideally, these results should be confirmed in longliners targeting species other than European hake.

A review of ocean chlorophyll algorithms and primary production models

NASA Astrophysics Data System (ADS)

Li, Jingwen; Zhou, Song; Lv, Nan

2015-12-01

This paper mainly introduces the five ocean chlorophyll concentration inversion algorithm and 3 main models for computing ocean primary production based on ocean chlorophyll concentration. Through the comparison of five ocean chlorophyll inversion algorithm, sums up the advantages and disadvantages of these algorithm,and briefly analyzes the trend of ocean primary production model.

Connecting Coastal Communities with Ocean Science: A Look at Ocean Sense and the Inclusion of Place-based Indigenous Knowledge

NASA Astrophysics Data System (ADS)

McLean, M. A.; Brown, J.; Hoeberechts, M.

2016-02-01

Ocean Networks Canada (ONC), an initiative of the University of Victoria, develops, operates, and maintains cabled ocean observatory systems. Technologies developed on the world-leading NEPTUNE and VENUS observatories have been adapted for small coastal installations called "community observatories," which enable community members to directly monitor conditions in the local ocean environment. In 2014, ONC pioneered an innovative educational program, Ocean Sense: Local observations, global connections, which introduces students and teachers to the technologies installed on community observatories. The program introduces middle and high school students to research methods in biology, oceanography and ocean engineering through hands-on activities. Ocean Sense includes a variety of resources and opportunities to excite students and spark curiosity about the ocean environment. The program encourages students to connect their local observations to global ocean processes and the observations of students in other geographic regions. The connection to place and local relevance of the program is further enhanced through an emphasis on Indigenous and place-based knowledge. ONC is working with coastal Indigenous communities in a collaborative process to include local knowledge, culture, and language in Ocean Sense materials. For this process to meaningful and culturally appropriate, ONC is relying on the guidance and oversight of Indigenous community educators and knowledge holders. Ocean Sense also includes opportunities for Indigenous youth and teachers in remote communities to connect in person, including an annual Ocean Science Symposium and professional development events for teachers. Building a program which embraces multiple perspectives is effective both in making ocean science more relevant to Indigenous students and in linking Indigenous knowledge and place-based knowledge to ocean science.

[Review of estimation on oceanic primary productivity by using remote sensing methods.

PubMed

Xu, Hong Yun; Zhou, Wei Feng; Ji, Shi Jian

2016-09-01

Accuracy estimation of oceanic primary productivity is of great significance in the assessment and management of fisheries resources, marine ecology systems, global change and other fields. The traditional measurement and estimation of oceanic primary productivity has to rely on in situ sample data by vessels. Satellite remote sensing has advantages of providing dynamic and eco-environmental parameters of ocean surface at large scale in real time. Thus, satellite remote sensing has increasingly become an important means for oceanic primary productivity estimation on large spatio-temporal scale. Combining with the development of ocean color sensors, the models to estimate the oceanic primary productivity by satellite remote sensing have been developed that could be mainly summarized as chlorophyll-based, carbon-based and phytoplankton absorption-based approach. The flexibility and complexity of the three kinds of models were presented in the paper. On this basis, the current research status for global estimation of oceanic primary productivity was analyzed and evaluated. In view of these, four research fields needed to be strengthened in further stu-dy: 1) Global oceanic primary productivity estimation should be segmented and studied, 2) to dee-pen the research on absorption coefficient of phytoplankton, 3) to enhance the technology of ocea-nic remote sensing, 4) to improve the in situ measurement of primary productivity.

Ocean Heat Content Reveals Secrets of Fish Migrations

PubMed Central

Luo, Jiangang; Ault, Jerald S.; Shay, Lynn K.; Hoolihan, John P.; Prince, Eric D.; Brown, Craig A.; Rooker, Jay R.

2015-01-01

For centuries, the mechanisms surrounding spatially complex animal migrations have intrigued scientists and the public. We present a new methodology using ocean heat content (OHC), a habitat metric that is normally a fundamental part of hurricane intensity forecasting, to estimate movements and migration of satellite-tagged marine fishes. Previous satellite-tagging research of fishes using archival depth, temperature and light data for geolocations have been too coarse to resolve detailed ocean habitat utilization. We combined tag data with OHC estimated from ocean circulation and transport models in an optimization framework that substantially improved geolocation accuracy over SST-based tracks. The OHC-based movement track provided the first quantitative evidence that many of the tagged highly migratory fishes displayed affinities for ocean fronts and eddies. The OHC method provides a new quantitative tool for studying dynamic use of ocean habitats, migration processes and responses to environmental changes by fishes, and further, improves ocean animal tracking and extends satellite-based animal tracking data for other potential physical, ecological, and fisheries applications. PMID:26484541

Department of Veterans Affairs, Journal of Rehabilitation Research and Development, Volume 30, Number 2, 1993

DTIC Science & Technology

1992-01-01

300 0 m V. 0 1 03 05 07 0W 01 03 0s o78s a les a Ste fr s. of Uw Flgure S. o 0 o 20 30 405 00 30o 80 00 10o o200o4o03040 7080o00x Resultant shear...Labora- liminary Findings. Tsubahara A, et al., Disabil tory, University of Wisconsin- Madison , 2000 Obser- Rehabil 14(4):163-167, 1992. vatory Dr., Madison ...Intervention on Rehabil- 94143-0728 itation Time in Patients with Thoracolumbar and Lumbar Spinal Cord Injuries. Rimoldi RL, et al., 130. Rehabilitation

Alternative approaches to plasma confinement

NASA Technical Reports Server (NTRS)

Roth, J. R.

1978-01-01

The paper discusses 20 plasma confinement schemes each representing an alternative to the tokamak fusion reactor. Attention is given to: (1) tokamak-like devices (TORMAC, Topolotron, and the Extrap concept), (2) stellarator-like devices (Torsatron and twisted-coil stellarators), (3) mirror machines (Astron and reversed-field devices, the 2XII B experiment, laser-heated solenoids, the LITE experiment, the Kaktus-Surmac concept), (4) bumpy tori (hot electron bumpy torus, toroidal minimum-B configurations), (5) electrostatically assisted confinement (electrostatically stuffed cusps and mirrors, electrostatically assisted toroidal confinement), (6) the Migma concept, and (7) wall-confined plasmas. The plasma parameters of the devices are presented and the advantages and disadvantages of each are listed.

Counting spinning dyons in maximal supergravity: the Hodge-elliptic genus for tori

NASA Astrophysics Data System (ADS)

Benjamin, Nathan; Kachru, Shamit; Tripathy, Arnav

2017-11-01

We consider M-theory compactified on T^4 × T^2 and describe the count of spinning 1/8-BPS states. This builds on the work of Maldacena-Moore-Strominger in the physics literature. It simultaneously provides a refinement of the recent mathematical work of Bryan-Oberdieck-Pandharipande-Yin and Oberdieck-Shen, which studied (non-motivic) reduced Donaldson-Thomas invariants of abelian surfaces and threefolds. As in previous work on K3 × T^2 compactification, we track angular momenta under both the SU(2)_L and SU(2)_R factors in the 5d little group, providing predictions for the relevant motivic curve counts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz

We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends onmore » the dimensionless spin of the rotating attractor.« less

Non-integrability vs. integrability in pentagram maps

NASA Astrophysics Data System (ADS)

Khesin, Boris; Soloviev, Fedor

2015-01-01

We revisit recent results on integrable cases for higher-dimensional generalizations of the 2D pentagram map: short-diagonal, dented, deep-dented, and corrugated versions, and define a universal class of pentagram maps, which are proved to possess projective duality. We show that in many cases the pentagram map cannot be included into integrable flows as a time-one map, and discuss how the corresponding notion of discrete integrability can be extended to include jumps between invariant tori. We also present a numerical evidence that certain generalizations of the integrable 2D pentagram map are non-integrable and present a conjecture for a necessary condition of their discrete integrability.

Quadratic Forms and Semiclassical Eigenfunction Hypothesis for Flat Tori

NASA Astrophysics Data System (ADS)

T. Sardari, Naser

2018-03-01

Let Q( X) be any integral primitive positive definite quadratic form in k variables, where {k≥4}, and discriminant D. For any integer n, we give an upper bound on the number of integral solutions of Q( X) = n in terms of n, k, and D. As a corollary, we prove a conjecture of Lester and Rudnick on the small scale equidistribution of almost all functions belonging to any orthonormal basis of a given eigenspace of the Laplacian on the flat torus {T^d} for {d≥ 5}. This conjecture is motivated by the work of Berry [2,3] on the semiclassical eigenfunction hypothesis.

Department of the Army Justification of Estimates for Fiscal Year 1985 Submitted to Congress February 1984, Procurement, Programs, Aircraft, Missiles, Weapons & Tracked Combat Vehicles. Part 4. Ammunition.

DTIC Science & Technology

1984-02-01

Bushmaster 5860108 - Volunteer AN - Intermolecular - Ethylenediamine 5.7 dinitrate/ amonium nitrate (M) 5860122 - X-Facility: I1W - Mine MM139 Volcano...1 40 13 0001 AdJullan te prior yew truat fund or d e -3,41 17.0001 Mece feeia of prior y Otlgtte -l -56,606 Unoba Igeted balane evatIlell. MY 21...transfarred 10.000 10,000 IobiIgst d balance allloe. MO 𔃾.40M2 For completles of prior year budgt plane *1 In 39.0001 Itdgot authrlIty 4-6 Fe’ tory

Representations of some quantum tori Lie subalgebras

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Jingjing; Wang, Song

2013-03-15

In this paper, we define the q-analog Virasoro-like Lie subalgebras in x{sub {infinity}}=a{sub {infinity}}(b{sub {infinity}}, c{sub {infinity}}, d{sub {infinity}}). The embedding formulas into x{sub {infinity}} are introduced. Irreducible highest weight representations of A(tilde sign){sub q}, B(tilde sign){sub q}, and C(tilde sign){sub q}-series of the q-analog Virasoro-like Lie algebras in terms of vertex operators are constructed. We also construct the polynomial representations of the A(tilde sign){sub q}, B(tilde sign){sub q}, C(tilde sign){sub q}, and D(tilde sign){sub q}-series of the q-analog Virasoro-like Lie algebras.

Nosé-Thermostated Mechanical Systems on the n-Torus

NASA Astrophysics Data System (ADS)

Butler, Leo T.

2018-02-01

Let {H(q,p) = 1/2{allel p allel}^2 + V(q)} be an n-degree of freedom C r mechanical Hamiltonian on {T^{*}{T}^n} where {r > 2n+2}. When the metric {{allel \\cdot allel}} is flat, the Nosé-thermostated system associated to H is shown to have a positive-measure set of invariant tori near the infinite temperature limit. This is shown to be true for all variable mass thermostats similar to Nosé's, too. These results complement results of Bulter (Nonlinearity 11(29):3454-3463, 2016), Legoll et al. (Arch Ration Mech Anal 184(3):449-463, 2007, Nonlinearity 22(7):1673-1694, 2009).

33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The...

33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The...

33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The...

33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The...

33 CFR 334.900 - Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.900 Section 334.900 Navigation and Navigable Waters... REGULATIONS § 334.900 Pacific Ocean, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The...

33 CFR 334.590 - Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. 334.590 Section 334.590 Navigation... RESTRICTED AREA REGULATIONS § 334.590 Atlantic Ocean off Cape Canaveral, Fla.; Air Force missile testing area, Patrick Air Force Base, Fla. (a) The danger zone. An area in the Atlantic Ocean immediately offshore from...

Satellite based Ocean Forecasting, the SOFT project

NASA Astrophysics Data System (ADS)

Stemmann, L.; Tintoré, J.; Moneris, S.

2003-04-01

The knowledge of future oceanic conditions would have enormous impact on human marine related areas. For such reasons, a number of international efforts are being carried out to obtain reliable and manageable ocean forecasting systems. Among the possible techniques that can be used to estimate the near future states of the ocean, an ocean forecasting system based on satellite imagery is developped through the Satelitte based Ocean ForecasTing project (SOFT). SOFT, established by the European Commission, considers the development of a forecasting system of the ocean space-time variability based on satellite data by using Artificial Intelligence techniques. This system will be merged with numerical simulation approaches, via assimilation techniques, to get a hybrid SOFT-numerical forecasting system of improved performance. The results of the project will provide efficient forecasting of sea-surface temperature structures, currents, dynamic height, and biological activity associated to chlorophyll fields. All these quantities could give valuable information on the planning and management of human activities in marine environments such as navigation, fisheries, pollution control, or coastal management. A detailed identification of present or new needs and potential end-users concerned by such an operational tool is being performed. The project would study solutions adapted to these specific needs.

Proceedings from the U.S. Army Corps of Engineers (USACE) and the National Oceanic and Atmospheric Administration (NOAA) Natural and Nature-Based Features Workshop

DTIC Science & Technology

2016-03-01

ERDC-EL Research Biologist/Certified Facilitator Mintz Jennifer NOAA-OAR-OAP Regional Coordinator- Ocean Acidification Program/Facilitator Payne Dr...National Oceanic United States Army United States and Atmospheric Engineer Research Army Corps Administration and Development of Engineers (NOAA...and the National Oceanic and Atmospheric Administration (NOAA) Natural and Nature-Based Features Workshop March 1-3, 2016 Charleston, South

Atmospheric correction using near-infrared bands for satellite ocean color data processing in the turbid western Pacific region.

PubMed

Wang, Menghua; Shi, Wei; Jiang, Lide

2012-01-16

A regional near-infrared (NIR) ocean normalized water-leaving radiance (nL(w)(λ)) model is proposed for atmospheric correction for ocean color data processing in the western Pacific region, including the Bohai Sea, Yellow Sea, and East China Sea. Our motivation for this work is to derive ocean color products in the highly turbid western Pacific region using the Geostationary Ocean Color Imager (GOCI) onboard South Korean Communication, Ocean, and Meteorological Satellite (COMS). GOCI has eight spectral bands from 412 to 865 nm but does not have shortwave infrared (SWIR) bands that are needed for satellite ocean color remote sensing in the turbid ocean region. Based on a regional empirical relationship between the NIR nL(w)(λ) and diffuse attenuation coefficient at 490 nm (K(d)(490)), which is derived from the long-term measurements with the Moderate-resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite, an iterative scheme with the NIR-based atmospheric correction algorithm has been developed. Results from MODIS-Aqua measurements show that ocean color products in the region derived from the new proposed NIR-corrected atmospheric correction algorithm match well with those from the SWIR atmospheric correction algorithm. Thus, the proposed new atmospheric correction method provides an alternative for ocean color data processing for GOCI (and other ocean color satellite sensors without SWIR bands) in the turbid ocean regions of the Bohai Sea, Yellow Sea, and East China Sea, although the SWIR-based atmospheric correction approach is still much preferred. The proposed atmospheric correction methodology can also be applied to other turbid coastal regions.

Parsec-scale jets and tori in seyfert galaxies

NASA Astrophysics Data System (ADS)

Roy, A. L.; Wrobel, J. M.; Wilson, A. S.; Ulvestad, J. S.; Norris, R. P.; Mundell, C. G.; Krichbaum, T. P.; Falcke, H.; Colbert, E. J. M.

2001-01-01

H. Falcke, T.P. Krichbaum, C.G. Mundell, J.S. Ulvestad, A.S. Wilson, J.M. Wrobel Active galaxies tend to be powerful or weak radio sources, and we still do not understand the underlying cause. Perhaps the engine is the same in both systems and the jet gets disrupted by dense interstellar medium in radio-quiet objects, or else the difference is intrinsic with jet power scaling with black hole spin. To distinguish, one can look for signs of interaction between the jet and the narrow-line region, and to measure the jet speed close to the jet base, before environmental effects become important. We find one-sided parsec-scale jet structures in Mrk 348, Mrk 231, NGC 4151, and NGC 5506 using VLBI, and we measure low jet speeds (typically <= 0.25 c). The one-sidedness probably is not due to Doppler boosting, but rather is probably free-free absorption. Plasma conditions required to produce the absorption are Ne >= 2 × 105 cm-3 assuming a path length of 0.1 pc, typical of that expected at the inner edge of the obscuring torus.

Topics in Two-Dimensional Quantum Gravity and Chern-Simons Gauge Theories

NASA Astrophysics Data System (ADS)

Zemba, Guillermo Raul

A series of studies in two and three dimensional theories is presented. The two dimensional problems are considered in the framework of String Theory. The first one determines the region of integration in the space of inequivalent tori of a tadpole diagram in Closed String Field Theory, using the naive Witten three-string vertex. It is shown that every surface is counted an infinite number of times and the source of this behavior is identified. The second study analyzes the behavior of the discrete matrix model of two dimensional gravity without matter using a mathematically well-defined construction, confirming several conjectures and partial results from the literature. The studies in three dimensions are based on Chern Simons pure gauge theory. The first one deals with the projection of the theory onto a two-dimensional surface of constant time, whereas the second analyzes the large N behavior of the SU(N) theory and makes evident a duality symmetry between the only two parameters of the theory. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253 -1690.).

33 CFR 334.866 - Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California; naval danger zone. 334.866 Section 334.866... AND RESTRICTED AREA REGULATIONS § 334.866 Pacific Ocean at Naval Base Coronado, in the City of...

33 CFR 334.866 - Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pacific Ocean at Naval Base Coronado, in the City of Coronado, San Diego County, California; naval danger zone. 334.866 Section 334.866... AND RESTRICTED AREA REGULATIONS § 334.866 Pacific Ocean at Naval Base Coronado, in the City of...

Global patterns of changes in underwater sound transmission caused by ocean acidification

NASA Astrophysics Data System (ADS)

Ilyina, T.; Zeebe, R. E.; Brewer, P. G.

2009-04-01

Oceanic uptake of man-made CO2 leads to a decrease in the ocean pH and carbonate saturation state. This processes, known as ocean acidification is expected to have adverse effects on a variety of marine organisms. A surprising consequence of ocean acidification, which has gone widely unrecognized, is its effect on underwater sound transmission. Low-frequency sound absorption in the ocean occurs due to chemical relaxation of the pH-dependent boric acid-borate ion reaction. As ocean pH drops, sound absorption in the audible range decreases. The decreased sound absorption will amplify ambient noise levels, and enhance long distance sound transmission, although its exact environmental impact is uncertain. Changes in the underwater sound absorption will affect the operation of scientific, commercial, and naval applications that are based on ocean acoustics, with yet unknown consequences for marine life. We project these changes using a global biogeochemical model (HAMOCC), which is forced by the anthropogenic CO2 emissions during the years 1800-2300. Based on model projections, we quantify when and where in the ocean these ocean chemistry induced perturbations in sound absorption will occur.

The color metamerism evaluation of paint based on ocean spectrum

NASA Astrophysics Data System (ADS)

Chen, Zhongwei; Huang, Hao; Liao, Ningfang

2018-03-01

The surface color of the sea is affected by many factors and will be different the due to the material difference in the sea. And the difference will be reflected in the ocean spectrum. If the paint materials of a ship can simulate the ocean surface color and the ocean spectrum at the same time. This will minimize the metamerism. In this paper, the method of metamerism is used to evaluate paint based on ocean spectrum, so that the color of the material affected by the light source will be reflected in the metamerism index.

Self-Organizing Maps-based ocean currents forecasting system.

PubMed

Vilibić, Ivica; Šepić, Jadranka; Mihanović, Hrvoje; Kalinić, Hrvoje; Cosoli, Simone; Janeković, Ivica; Žagar, Nedjeljka; Jesenko, Blaž; Tudor, Martina; Dadić, Vlado; Ivanković, Damir

2016-03-16

An ocean surface currents forecasting system, based on a Self-Organizing Maps (SOM) neural network algorithm, high-frequency (HF) ocean radar measurements and numerical weather prediction (NWP) products, has been developed for a coastal area of the northern Adriatic and compared with operational ROMS-derived surface currents. The two systems differ significantly in architecture and algorithms, being based on either unsupervised learning techniques or ocean physics. To compare performance of the two methods, their forecasting skills were tested on independent datasets. The SOM-based forecasting system has a slightly better forecasting skill, especially during strong wind conditions, with potential for further improvement when data sets of higher quality and longer duration are used for training.

Self-Organizing Maps-based ocean currents forecasting system

PubMed Central

Vilibić, Ivica; Šepić, Jadranka; Mihanović, Hrvoje; Kalinić, Hrvoje; Cosoli, Simone; Janeković, Ivica; Žagar, Nedjeljka; Jesenko, Blaž; Tudor, Martina; Dadić, Vlado; Ivanković, Damir

2016-01-01

An ocean surface currents forecasting system, based on a Self-Organizing Maps (SOM) neural network algorithm, high-frequency (HF) ocean radar measurements and numerical weather prediction (NWP) products, has been developed for a coastal area of the northern Adriatic and compared with operational ROMS-derived surface currents. The two systems differ significantly in architecture and algorithms, being based on either unsupervised learning techniques or ocean physics. To compare performance of the two methods, their forecasting skills were tested on independent datasets. The SOM-based forecasting system has a slightly better forecasting skill, especially during strong wind conditions, with potential for further improvement when data sets of higher quality and longer duration are used for training. PMID:26979129

Towards a quantification of ocean wave heights off the west coast of Ireland using land based seismic data

NASA Astrophysics Data System (ADS)

Donne, S.; Bean, C. J.; Lokmer, I.; Lambkin, K.; Creamer, C.

2012-12-01

Ocean gravity waves are driven by atmospheric pressure systems. Their interactions with one another and reflection off coastlines generate pressure changes at the sea floor. These pressure fluctuations are the cause of continuous background seismic noise known as microseisms. The levels of microseism activity vary as a function of the sea state and increase during periods of intensive ocean wave activity. In 2011 a seismic network was deployed along the west coast of Ireland to continuously record microseisms generated in the Atlantic Ocean, as part of the Wave Observation (WaveObs) project based in University College Dublin. This project aims to determine the characteristics of the causative ocean gravity waves through calibration of the microseism data with ocean buoy data. In initial tests we are using a Backpropagation Feed-forward Artificial Neural Network (BP ANN) to establish the underlying relationships between microseisms and ocean waves. ANNs were originally inspired by studies of the mammalian brain and nervous system and are designed to learn by example. If successful these tools could then be used to estimate ocean wave heights and wave periods using a land-based seismic network and complement current wave observations being made offshore by marine buoys. Preliminary ANN results are promising with the network successfully able to reconstruct trends in ocean wave heights and periods. Microseisms can provide significant information about oceanic processes. With a deeper understanding of how these processes work there is potential for 1) locating and tracking the evolution of the largest waves in the Atlantic and 2) reconstructing the wave climate off the west coast of Ireland using legacy seismic data on a longer time scale than is currently available using marine based observations.

The Great Chilean Tsunamis of 2010, 2014 and 2015 on the Coast and Offshore of Mexico: Comparative Features Based on Open-Ocean Energy Parameterization

NASA Astrophysics Data System (ADS)

Rabinovich, A.; Zaytsev, O.; Thomson, R.

2016-12-01

The three recent great earthquakes offshore of Chile on 27 February 2010 (Maule, Mw 8.8), 1 April 2014 (Iquique, Mw 8.2) and 16 September 2015 (Illapel, Mw 8.3) generated major trans-oceanic tsunamis that spread throughout the entire Pacific Ocean and were measured by numerous coastal tide gauges and open-ocean DART stations. Statistical and spectral analyses of the tsunami waves from the three events recorded on the Pacific coast of Mexico enabled us to compare the events and to identify coastal "hot spots", regions with maximum tsunami risk. Based on joint spectral analyses of tsunamis and background noise, we have developed a method for reconstructing the "true" tsunami spectra in the deep ocean. The "reconstructed" open-ocean tsunami spectra are in excellent agreement with the actual tsunami spectra evaluated from direct analysis of the DART records offshore of Mexico. We have further used the spectral estimates to parameterize the energy of the three Chilean tsunamis based on the total open-ocean tsunami energy and frequency content of the individual events.

Ocean Cooling Pattern at the Last Glacial Maximum

DOE PAGES

Zhuang, Kelin; Giardino, John R.

2012-01-01

Ocean temperature and ocean heat content change are analyzed based on four PMIP3 model results at the Last Glacial Maximum relative to the prehistorical run. Ocean cooling mostly occurs in the upper 1000 m depth and varies spatially in the tropical and temperate zones. The Atlantic Ocean experiences greater cooling than the rest of the ocean basins. Ocean cooling is closely related to the weakening of meridional overturning circulation and enhanced intrusion of Antarctic Bottom Water into the North Atlantic.

Sea surface temperature predictions using a multi-ocean analysis ensemble scheme

NASA Astrophysics Data System (ADS)

Zhang, Ying; Zhu, Jieshun; Li, Zhongxian; Chen, Haishan; Zeng, Gang

2017-08-01

This study examined the global sea surface temperature (SST) predictions by a so-called multiple-ocean analysis ensemble (MAE) initialization method which was applied in the National Centers for Environmental Prediction (NCEP) Climate Forecast System Version 2 (CFSv2). Different from most operational climate prediction practices which are initialized by a specific ocean analysis system, the MAE method is based on multiple ocean analyses. In the paper, the MAE method was first justified by analyzing the ocean temperature variability in four ocean analyses which all are/were applied for operational climate predictions either at the European Centre for Medium-range Weather Forecasts or at NCEP. It was found that these systems exhibit substantial uncertainties in estimating the ocean states, especially at the deep layers. Further, a set of MAE hindcasts was conducted based on the four ocean analyses with CFSv2, starting from each April during 1982-2007. The MAE hindcasts were verified against a subset of hindcasts from the NCEP CFS Reanalysis and Reforecast (CFSRR) Project. Comparisons suggested that MAE shows better SST predictions than CFSRR over most regions where ocean dynamics plays a vital role in SST evolutions, such as the El Niño and Atlantic Niño regions. Furthermore, significant improvements were also found in summer precipitation predictions over the equatorial eastern Pacific and Atlantic oceans, for which the local SST prediction improvements should be responsible. The prediction improvements by MAE imply a problem for most current climate predictions which are based on a specific ocean analysis system. That is, their predictions would drift towards states biased by errors inherent in their ocean initialization system, and thus have large prediction errors. In contrast, MAE arguably has an advantage by sampling such structural uncertainties, and could efficiently cancel these errors out in their predictions.

The Change in Oceanic O2 Inventory Associated with Recent Global Warming

NASA Technical Reports Server (NTRS)

Keeling, Ralph; Garcia, Hernan

2002-01-01

Oceans general circulation models predict that global warming may cause a decrease in the oceanic O2 inventory and an associated O2 outgassing. An independent argument is presented here in support of this prediction based on observational evidence of the ocean's biogeochemical response to natural warming. On time scales from seasonal to centennial, natural O2 flux/heat flux ratios are shown to occur in a range of 2 to 10 nmol O2 per Joule of warming, with larger ratios typically occurring at higher latitudes and over longer time scales. The ratios are several times larger than would be expected solely from the effect of heating on the O2 solubility, indicating that most of the O2 exchange is biologically mediated through links between heating and stratification. The change in oceanic O2 inventory through the 1990's is estimated to be 0.3 - 0.4 x 10(exp 14) mol O2 per year based on scaling the observed anomalous long-term ocean warming by natural O2 flux/heating ratios and allowing for uncertainty due to decadal variability. Implications are discussed for carbon budgets based on observed changes in atmospheric O2/N2 ratio and based on observed changes in ocean dissolved inorganic carbon.

The inverse problem: Ocean tides derived from earth tide observations

NASA Technical Reports Server (NTRS)

Kuo, J. T.

1978-01-01

Indirect mapping ocean tides by means of land and island-based tidal gravity measurements is presented. The inverse scheme of linear programming is used for indirect mapping of ocean tides. Open ocean tides were measured by the numerical integration of Laplace's tidal equations.

Surface flux and ocean heat transport convergence contributions to seasonal and interannual variations of ocean heat content

NASA Astrophysics Data System (ADS)

Roberts, C. D.; Palmer, M. D.; Allan, R. P.; Desbruyeres, D. G.; Hyder, P.; Liu, C.; Smith, D.

2017-01-01

We present an observation-based heat budget analysis for seasonal and interannual variations of ocean heat content (H) in the mixed layer (Hmld) and full-depth ocean (Htot). Surface heat flux and ocean heat content estimates are combined using a novel Kalman smoother-based method. Regional contributions from ocean heat transport convergences are inferred as a residual and the dominant drivers of Hmld and Htot are quantified for seasonal and interannual time scales. We find that non-Ekman ocean heat transport processes dominate Hmld variations in the equatorial oceans and regions of strong ocean currents and substantial eddy activity. In these locations, surface temperature anomalies generated by ocean dynamics result in turbulent flux anomalies that drive the overlying atmosphere. In addition, we find large regions of the Atlantic and Pacific oceans where heat transports combine with local air-sea fluxes to generate mixed layer temperature anomalies. In all locations, except regions of deep convection and water mass transformation, interannual variations in Htot are dominated by the internal rearrangement of heat by ocean dynamics rather than the loss or addition of heat at the surface. Our analysis suggests that, even in extratropical latitudes, initialization of ocean dynamical processes could be an important source of skill for interannual predictability of Hmld and Htot. Furthermore, we expect variations in Htot (and thus thermosteric sea level) to be more predictable than near surface temperature anomalies due to the increased importance of ocean heat transport processes for full-depth heat budgets.

A real-time photo-realistic rendering algorithm of ocean color based on bio-optical model

NASA Astrophysics Data System (ADS)

Ma, Chunyong; Xu, Shu; Wang, Hongsong; Tian, Fenglin; Chen, Ge

2016-12-01

A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton, colored dissolved organic material (CDOM), inorganic suspended particle, etc., which have different contributions to absorption and scattering of light. We decompose the emergent light of the ocean surface into the reflected light from the sun and the sky, and the subsurface scattering light. We establish an ocean surface transmission model based on ocean bidirectional reflectance distribution function (BRDF) and the Fresnel law, and this model's outputs would be the incident light parameters of subsurface scattering. Using ocean subsurface scattering algorithm combined with bio-optical model, we compute the scattering light emergent radiation in different directions. Then, we blend the reflection of sunlight and sky light to implement the real-time ocean color rendering in graphics processing unit (GPU). Finally, we use two kinds of radiance reflectance calculated by Hydrolight radiative transfer model and our algorithm to validate the physical reality of our method, and the results show that our algorithm can achieve real-time highly realistic ocean color scenes.

Observationally-based Metrics of Ocean Carbon and Biogeochemical Variables are Essential for Evaluating Earth System Model Projections

NASA Astrophysics Data System (ADS)

Russell, J. L.; Sarmiento, J. L.

2017-12-01

The Southern Ocean is central to the climate's response to increasing levels of atmospheric greenhouse gases as it ventilates a large fraction of the global ocean volume. Global coupled climate models and earth system models, however, vary widely in their simulations of the Southern Ocean and its role in, and response to, the ongoing anthropogenic forcing. Due to its complex water-mass structure and dynamics, Southern Ocean carbon and heat uptake depend on a combination of winds, eddies, mixing, buoyancy fluxes and topography. Understanding how the ocean carries heat and carbon into its interior and how the observed wind changes are affecting this uptake is essential to accurately projecting transient climate sensitivity. Observationally-based metrics are critical for discerning processes and mechanisms, and for validating and comparing climate models. As the community shifts toward Earth system models with explicit carbon simulations, more direct observations of important biogeochemical parameters, like those obtained from the biogeochemically-sensored floats that are part of the Southern Ocean Carbon and Climate Observations and Modeling project, are essential. One goal of future observing systems should be to create observationally-based benchmarks that will lead to reducing uncertainties in climate projections, and especially uncertainties related to oceanic heat and carbon uptake.

Studies of oceanic tectonics based on GEOS-3 satellite altimetry

NASA Technical Reports Server (NTRS)

Poehls, K. A.; Kaula, W. M.; Schubert, G.; Sandwell, D.

1979-01-01

Using statistical analysis, geoidal admittance (the relationship between the ocean geoid and seafloor topography) obtained from GEOS-3 altimetry was compared to various model admittances. Analysis of several altimetry tracks in the Pacific Ocean demonstrated a low coherence between altimetry and seafloor topography except where the track crosses active or recent tectonic features. However, global statistical studies using the much larger data base of all available gravimetry showed a positive correlation of oceanic gravity with topography. The oceanic lithosphere was modeled by simultaneously inverting surface wave dispersion, topography, and gravity data. Efforts to incorporate geoid data into the inversion showed that the base of the subchannel can be better resolved with geoid rather than gravity data. Thermomechanical models of seafloor spreading taking into account differing plate velocities, heat source distributions, and rock rheologies were discussed.

Ocean Commission Report Includes Key Recommendations for Science and Governance

NASA Astrophysics Data System (ADS)

Showstack, Randy

2004-05-01

The preliminary report of the U.S. Commission on Ocean Policy, released on 20 April, calls for ecosystem-based management of the oceans, dramatically restructuring federal governance oversight of ocean issues, and doubling the federal ocean and coastal research budget over the next five years to $1.3 billion per year. The report by the congressionally-mandated and presidentially-appointed commission includes nearly 200 recommendations for establishing a coordinated and comprehensive national ocean policy framework.

Some constructions of biharmonic maps and Chen’s conjecture on biharmonic hypersurfaces

NASA Astrophysics Data System (ADS)

Ou, Ye-Lin

2012-04-01

We give several construction methods and use them to produce many examples of proper biharmonic maps including biharmonic tori of any dimension in Euclidean spheres (Theorem 2.2, Corollaries 2.3, 2.4 and 2.6), biharmonic maps between spheres (Theorem 2.9) and into spheres (Theorem 2.10) via orthogonal multiplications and eigenmaps. We also study biharmonic graphs of maps, derive the equation for a function whose graph is a biharmonic hypersurface in a Euclidean space, and give an equivalent formulation of Chen's conjecture on biharmonic hypersurfaces by using the biharmonic graph equation (Theorem 4.1) which paves a way for the analytic study of the conjecture.

Background Independence and Duality Invariance in String Theory.

PubMed

Hohm, Olaf

2017-03-31

Closed string theory exhibits an O(D,D) duality symmetry on tori, which in double field theory is manifest before compactification. I prove that to first order in α^{'} there is no manifestly background independent and duality invariant formulation of bosonic string theory in terms of a metric, b field, and dilaton. To this end I use O(D,D) invariant second order perturbation theory around flat space to show that the unique background independent candidate expression for the gauge algebra at order α^{'} is inconsistent with the Jacobi identity. A background independent formulation exists instead for frame variables subject to α^{'}-deformed frame transformations (generalized Green-Schwarz transformations). Potential applications for curved backgrounds, as in cosmology, are discussed.

Design and Execution of the Hypersonic Inflatable Aerodynamic Decelerator Large-Article Wind Tunnel Experiment

NASA Technical Reports Server (NTRS)

Cassell, Alan M.

2013-01-01

The testing of 3- and 6-meter diameter Hypersonic Inflatable Aerodynamic Decelerator (HIAD) test articles was completed in the National Full-Scale Aerodynamics Complex 40 ft x 80 ft Wind Tunnel test section. Both models were stacked tori, constructed as 60 degree half-angle sphere cones. The 3-meter HIAD was tested in two configurations. The first 3-meter configuration utilized an instrumented flexible aerodynamic skin covering the inflatable aeroshell surface, while the second configuration employed a flight-like flexible thermal protection system. The 6-meter HIAD was tested in two structural configurations (with and without an aft-mounted stiffening torus near the shoulder), both utilizing an instrumented aerodynamic skin.

On E-discretization of tori of compact simple Lie groups. II

NASA Astrophysics Data System (ADS)

Hrivnák, Jiří; Juránek, Michal

2017-10-01

Ten types of discrete Fourier transforms of Weyl orbit functions are developed. Generalizing one-dimensional cosine, sine, and exponential, each type of the Weyl orbit function represents an exponential symmetrized with respect to a subgroup of the Weyl group. Fundamental domains of even affine and dual even affine Weyl groups, governing the argument and label symmetries of the even orbit functions, are determined. The discrete orthogonality relations are formulated on finite sets of points from the refinements of the dual weight lattices. Explicit counting formulas for the number of points of the discrete transforms are deduced. Real-valued Hartley orbit functions are introduced, and all ten types of the corresponding discrete Hartley transforms are detailed.

Using Combined Marine Spatial Planning Tools and Observing System Experiments to define Gaps in the Emerging European Ocean Observing System.

NASA Astrophysics Data System (ADS)

Nolan, G.; Pinardi, N.; Vukicevic, T.; Le Traon, P. Y.; Fernandez, V.

2016-02-01

Ocean observations are critical to providing accurate ocean forecasts that support operational decision making in European open and coastal seas. Observations are available in many forms from Fixed platforms e.g. Moored Buoys and tide gauges, underway measurements from Ferrybox systems, High Frequency radars and more recently from underwater Gliders and profiling floats. Observing System Simulation Experiments have been conducted to examine the relative contribution of each type of platform to an improvement in our ability to accurately forecast the future state of the ocean with HF radar and Gliders showing particular promise in improving model skill. There is considerable demand for ecosystem products and services from today's ocean observing system and biogeochemical observations are still relatively sparse particularly in coastal and shelf seas. There is a need to widen the techniques used to assess the fitness for purpose and gaps in the ocean observing system. As well as Observing System Simulation Experiments that quantify the effect of observations on the overall model skill we present a gap analysis based on (1) Examining where high model skill is required based on a marine spatial planning analysis of European seas i.e where does activity take place that requires more accurate forecasts? and (2) assessing gaps based on the capacity of the observing system to answer key societal challenges e.g. site suitability for aquaculture and ocean energy, oil spill response and contextual oceanographic products for fisheries and ecosystems. The broad based analysis will inform the development of the proposed European Ocean Observing System as a contribution to the Global Ocean Observing System (GOOS).

Shipborne LF-VLF oceanic lightning observations and modeling

NASA Astrophysics Data System (ADS)

Zoghzoghy, F. G.; Cohen, M. B.; Said, R. K.; Lehtinen, N. G.; Inan, U. S.

2015-10-01

Approximately 90% of natural lightning occurs over land, but recent observations, using Global Lightning Detection (GLD360) geolocation peak current estimates and satellite optical data, suggested that cloud-to-ground flashes are on average stronger over the ocean. We present initial statistics from a novel experiment using a Low Frequency (LF) magnetic field receiver system installed aboard the National Oceanic Atmospheric Agency (NOAA) Ronald W. Brown research vessel that allowed the detection of impulsive radio emissions from deep-oceanic discharges at short distances. Thousands of LF waveforms were recorded, facilitating the comparison of oceanic waveforms to their land counterparts. A computationally efficient electromagnetic radiation model that accounts for propagation over lossy and curved ground is constructed and compared with previously published models. We include the effects of Earth curvature on LF ground wave propagation and quantify the effects of channel-base current risetime, channel-base current falltime, and return stroke speed on the radiated LF waveforms observed at a given distance. We compare simulation results to data and conclude that previously reported larger GLD360 peak current estimates over the ocean are unlikely to fully result from differences in channel-base current risetime, falltime, or return stroke speed between ocean and land flashes.

Schwarz-Christoffel Conformal Mapping based Grid Generation for Global Oceanic Circulation Models

NASA Astrophysics Data System (ADS)

Xu, Shiming

2015-04-01

We propose new grid generation algorithms for global ocean general circulation models (OGCMs). Contrary to conventional, analytical forms based dipolar or tripolar grids, the new algorithm are based on Schwarz-Christoffel (SC) conformal mapping with prescribed boundary information. While dealing with the conventional grid design problem of pole relocation, it also addresses more advanced issues of computational efficiency and the new requirements on OGCM grids arisen from the recent trend of high-resolution and multi-scale modeling. The proposed grid generation algorithm could potentially achieve the alignment of grid lines to coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the generated grids are still orthogonal curvilinear, they can be readily 10 utilized in existing Bryan-Cox-Semtner type ocean models. The proposed methodology can also be applied to the grid generation task for regional ocean modeling when complex land-ocean distribution is present.

Introducing Ocean Science Research to Two-Year College (2YC) Students Through Inquiry-Based Experiences

NASA Astrophysics Data System (ADS)

Gamage, K. R.

2016-02-01

An effective approach to introduce 2YC students to ocean science research is through propagating inquiry-based experiences into existing geosciences courses using a series of research activities. The proposed activity is based on scientific ocean drilling, where students begin their research experience (pre-field activity) by reading articles from scientific journals and analyzing and interpreting core and log data on a specific research topic. At the end of the pre-field activity, students will visit the Gulf Coast Repository to examine actual cores, smear slides, thin sections etc. After the visit, students will integrate findings from their pre-field and field activities to produce a term paper. These simple activities allow students to experience in the iterative process of scientific research, illuminates how scientists approach ocean science, and can be the hook to get students interested in pursuing ocean science as a career.

Changes in Ocean Heat, Carbon Content, and Ventilation: A Review of the First Decade of GO-SHIP Global Repeat Hydrography.

PubMed

Talley, L D; Feely, R A; Sloyan, B M; Wanninkhof, R; Baringer, M O; Bullister, J L; Carlson, C A; Doney, S C; Fine, R A; Firing, E; Gruber, N; Hansell, D A; Ishii, M; Johnson, G C; Katsumata, K; Key, R M; Kramp, M; Langdon, C; Macdonald, A M; Mathis, J T; McDonagh, E L; Mecking, S; Millero, F J; Mordy, C W; Nakano, T; Sabine, C L; Smethie, W M; Swift, J H; Tanhua, T; Thurnherr, A M; Warner, M J; Zhang, J-Z

2016-01-01

Global ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting ocean change. The ocean, a central component of Earth's climate system, is taking up most of Earth's excess anthropogenic heat, with about 19% of this excess in the abyssal ocean beneath 2,000 m, dominated by Southern Ocean warming. The ocean also has taken up about 27% of anthropogenic carbon, resulting in acidification of the upper ocean. Increased stratification has resulted in a decline in oxygen and increase in nutrients in the Northern Hemisphere thermocline and an expansion of tropical oxygen minimum zones. Southern Hemisphere thermocline oxygen increased in the 2000s owing to stronger wind forcing and ventilation. The most recent decade of global hydrography has mapped dissolved organic carbon, a large, bioactive reservoir, for the first time and quantified its contribution to export production (∼20%) and deep-ocean oxygen utilization. Ship-based measurements also show that vertical diffusivity increases from a minimum in the thermocline to a maximum within the bottom 1,500 m, shifting our physical paradigm of the ocean's overturning circulation.

Ocean acidification in a geoengineering context

PubMed Central

Williamson, Phillip; Turley, Carol

2012-01-01

Fundamental changes to marine chemistry are occurring because of increasing carbon dioxide (CO2) in the atmosphere. Ocean acidity (H+ concentration) and bicarbonate ion concentrations are increasing, whereas carbonate ion concentrations are decreasing. There has already been an average pH decrease of 0.1 in the upper ocean, and continued unconstrained carbon emissions would further reduce average upper ocean pH by approximately 0.3 by 2100. Laboratory experiments, observations and projections indicate that such ocean acidification may have ecological and biogeochemical impacts that last for many thousands of years. The future magnitude of such effects will be very closely linked to atmospheric CO2; they will, therefore, depend on the success of emission reduction, and could also be constrained by geoengineering based on most carbon dioxide removal (CDR) techniques. However, some ocean-based CDR approaches would (if deployed on a climatically significant scale) re-locate acidification from the upper ocean to the seafloor or elsewhere in the ocean interior. If solar radiation management were to be the main policy response to counteract global warming, ocean acidification would continue to be driven by increases in atmospheric CO2, although with additional temperature-related effects on CO2 and CaCO3 solubility and terrestrial carbon sequestration. PMID:22869801

Deep Water Ocean Acoustics

DTIC Science & Technology

2015-07-17

under- ice scattering, bathymetric diffraction and the application of the ocean acoustic Parabolic Equation to infrasound. 2. Tasks a. Task 1...and Climate of the Ocean, Phase II (ECCO2): High-Resolution Global-Ocean and Sea- Ice Data Synthesis) model re- analysis for the years 1992 and 1993...The ECCO2 model is a state estimation based upon data syntheses obtained by least squares fitting of the global ocean and sea- ice configuration of

75 FR 54497 - Ocean Dumping; Guam Ocean Dredged Material Disposal Site Designation

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

... of special scientific importance, and other legitimate uses of the ocean. Minor short-term... option available since 1997. EPA determined that there is a long-term need for an ocean disposal site... Guam and surrounding waters. This is based on the long-term need to support the Naval and commercial...

New Observationally-Based Metrics for the Analysis of Coupled Climate Model and Earth System Model Simulations of the Southern Ocean

NASA Astrophysics Data System (ADS)

Russell, J. L.

2014-12-01

The exchange of heat and carbon dioxide between the atmosphere and ocean are major controls on Earth's climate under conditions of anthropogenic forcing. The Southern Ocean south of 30°S, occupying just over ¼ of the surface ocean area, accounts for a disproportionate share of the vertical exchange of properties between the deep and surface waters of the ocean and between the surface ocean and the atmosphere; thus this region can be disproportionately influential on the climate system. Despite the crucial role of the Southern Ocean in the climate system, understanding of the particular mechanisms involved remains inadequate, and the model studies underlying many of these results are highly controversial. As part of the overall goal of working toward reducing uncertainties in climate projections, we present an analysis using new data/model metrics based on a unified framework of theory, quantitative datasets, and numerical modeling. These new metrics quantify the mechanisms, processes, and tendencies relevant to the role of the Southern Ocean in climate.

THE DUST SUBLIMATION RADIUS AS AN OUTER ENVELOPE TO THE BULK OF THE NARROW Fe Kα LINE EMISSION IN TYPE 1 AGNs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gandhi, Poshak; Hönig, Sebastian F.; Kishimoto, Makoto

2015-10-20

The Fe Kα emission line is the most ubiquitous feature in the X-ray spectra of active galactic nuclei (AGNs), but the origin of its narrow core remains uncertain. Here, we investigate the connection between the sizes of the Fe Kα core emission regions and the measured sizes of the dusty tori in 13 local Type 1 AGNs. The observed Fe Kα emission radii (R{sub Fe}) are determined from spectrally resolved line widths in X-ray grating spectra, and the dust sublimation radii (R{sub dust}) are measured either from optical/near-infrared (NIR) reverberation time lags or from resolved NIR interferometric data. This directmore » comparison shows, on an object-by-object basis, that the dust sublimation radius forms an outer envelope to the bulk of the Fe Kα emission. R{sub Fe} matches R{sub dust} well in the AGNs, with the best constrained line widths currently. In a significant fraction of objects without a clear narrow line core, R{sub Fe} is similar to, or smaller than, the radius of the optical broad line region. These facts place important constraints on the torus geometries for our sample. Extended tori in which the solid angle of fluorescing gas peaks at well beyond the dust sublimation radius can be ruled out. We also test for luminosity scalings of R{sub Fe}, finding that the Eddington ratio is not a prime driver in determining the line location in our sample. We also discuss in detail potential caveats of data analysis and instrumental limitations, simplistic line modeling, uncertain black hole masses, and sample selection, showing that none of these is likely to bias our core result. The calorimeter on board Astro-H will soon vastly increase the parameter space over which line measurements can be made, overcoming many of these limitations.« less

Chaotic trajectories in the standard map. The concept of anti-integrability

NASA Astrophysics Data System (ADS)

Aubry, Serge; Abramovici, Gilles

1990-07-01

A rigorous proof is given in the standard map (associated with a Frenkel-Kontorowa model) for the existence of chaotic trajectories with unbounded momenta for large enough coupling constant k > k0. These chaotic trajectories (with finite entropy per site) are coded by integer sequences { mi} such that the sequence bi = |m i+1 + m i-1-2m i| be bounded by some integer b. The bound k0 in k depends on b and can be lowered for coding sequences { mi} fulfilling more restrictive conditions. The obtained chaotic trajectories correspond to stationary configurations of the Frenkel-Kontorowa model with a finite (non-zero) photon gap (called gap parameter in dimensionless units). This property implies that the trajectory (or the configuration { ui}) can be uniquely continued as a uniformly continuous function of the model parameter k in some neighborhood of the initial configuration. A non-zero gap parameter implies that the Lyapunov coefficient is strictly positive (when it is defined). In addition, the existence of dilating and contracting manifolds is proven for these chaotic trajectories. “Exotic” trajectories such as ballistic trajectories are also proven to exist as a consequence of these theorems. The concept of anti-integrability emerges from these theorems. In the anti-integrable limit which can be only defined for a discrete time dynamical system, the coordinates of the trajectory at time i do not depend on the coordinates at time i - 1. Thus, at this singular limit, the existence of chaotic trajectories is trivial and the dynamical system reduces to a Bernoulli shift. It is well known that the KAM tori of symplectic dynamical originates by continuity from the invariant tori which exists in the integrible limit (under certain conditions). In a similar way, it appears that the chaotic trajectories of dynamical systems originate by continuity from those which exists at the anti-integrable limits (also under certain conditions).

The dual targeting of insulin and insulin-like growth factor 1 receptor enhances the mTOR inhibitor-mediated antitumor efficacy in hepatocellular carcinoma

PubMed Central

Pivonello, Claudia; Negri, Mariarosaria; De Martino, Maria Cristina; Napolitano, Maria; de Angelis, Cristina; Provvisiero, Donatella Paola; Cuomo, Gaia; Auriemma, Renata Simona; Simeoli, Chiara; Izzo, Francesco; Colao, Annamaria; Hofland, Leo J.; Pivonello, Rosario

2016-01-01

Deregulation of mTOR and IGF pathways is frequent in hepatocellular carcinoma (HCC), thus mTOR and IGF1R represent suitable therapeutic targets in HCC. The aim of this study was to evaluate the effects of mTOR inhibitors (mTORi) and OSI-906, blocker of IGF1R/IR, on HCC cell proliferation, viability, migration and invasion, and alpha-fetoprotein (α-FP) secretion. In HepG2 and HuH-7 we evaluated, the expression of mTOR and IGF pathway components; the effects of Sirolimus, Everolimus, Temsirolimus and OSI-906 on cell proliferation; the effects of Sirolimus, OSI-906, and their combination, on cell secretion, proliferation, viability, cell cycle, apoptosis, invasion and migration. Moreover, intracellular mechanisms underlying these cell functions were evaluated in both cell lines. Our results show that HepG2 and HuH-7 present with the same mRNA expression profile with high levels of IGF2. OSI-906 inhibited cell proliferation at high concentration, while mTORi suppressed cell proliferation in a dose-time dependent manner in both cell lines. The co-treatment showed an additive inhibitory effect on cell proliferation and viability. This effect was not related to induction of apoptosis, but to G0/G1 phase block. Moreover, the co-treatment prevented the Sirolimus-induced AKT activation as escape mechanism. Both agents demonstrated to be differently effective in inhibiting α-FP secretion. Sirolimus, OSI-906, and their combination, blocked cell migration and invasion in HuH-7. These findings indicate that, co-targeting of IGF1R/IR and mTOR pathways could be a novel therapeutic approach in the management of HCC, in order to maximize antitumoral effect and to prevent the early development of resistance mechanisms. PMID:26756219

New closed analytical solutions for geometrically thick fluid tori around black holes. Numerical evolution and the onset of the magneto-rotational instability

NASA Astrophysics Data System (ADS)

Witzany, V.; Jefremov, P.

2018-06-01

Context. When a black hole is accreting well below the Eddington rate, a geometrically thick, radiatively inefficient state of the accretion disk is established. There is a limited number of closed-form physical solutions for geometrically thick (nonselfgravitating) toroidal equilibria of perfect fluids orbiting a spinning black hole, and these are predominantly used as initial conditions for simulations of accretion in the aforementioned mode. However, different initial configurations might lead to different results and thus observational predictions drawn from such simulations. Aims: We aim to expand the known equilibria by a number of closed multiparametric solutions with various possibilities of rotation curves and geometric shapes. Then, we ask whether choosing these as initial conditions influences the onset of accretion and the asymptotic state of the disk. Methods: We have investigated a set of examples from the derived solutions in detail; we analytically estimate the growth of the magneto-rotational instability (MRI) from their rotation curves and evolve the analytically obtained tori using the 2D magneto-hydrodynamical code HARM. Properties of the evolutions are then studied through the mass, energy, and angular-momentum accretion rates. Results: The rotation curve has a decisive role in the numerical onset of accretion in accordance with our analytical MRI estimates: in the first few orbital periods, the average accretion rate is linearly proportional to the initial MRI rate in the toroids. The final state obtained from any initial condition within the studied class after an evolution of ten or more orbital periods is mostly qualitatively identical and the quantitative properties vary within a single order of magnitude. The average values of the energy of the accreted fluid have an irregular dependency on initial data, and in some cases fluid with energies many times its rest mass is systematically accreted.

Tools and Methods for Visualization of Mesoscale Ocean Eddies

NASA Astrophysics Data System (ADS)

Bemis, K. G.; Liu, L.; Silver, D.; Kang, D.; Curchitser, E.

2017-12-01

Mesoscale ocean eddies form in the Gulf Stream and transport heat and nutrients across the ocean basin. The internal structure of these three-dimensional eddies and the kinematics with which they move are critical to a full understanding of their transport capacity. A series of visualization tools have been developed to extract, characterize, and track ocean eddies from 3D modeling results, to visually show the ocean eddy story by applying various illustrative visualization techniques, and to interactively view results stored on a server from a conventional browser. In this work, we apply a feature-based method to track instances of ocean eddies through the time steps of a high-resolution multidecadal regional ocean model and generate a series of eddy paths which reflect the life cycle of individual eddy instances. The basic method uses the Okubu-Weiss parameter to define eddy cores but could be adapted to alternative specifications of an eddy. Stored results include pixel-lists for each eddy instance, tracking metadata for eddy paths, and physical and geometric properties. In the simplest view, isosurfaces are used to display eddies along an eddy path. Individual eddies can then be selected and viewed independently or an eddy path can be viewed in the context of all eddy paths (longer than a specified duration) and the ocean basin. To tell the story of mesoscale ocean eddies, we combined illustrative visualization techniques, including visual effectiveness enhancement, focus+context, and smart visibility, with the extracted volume features to explore eddy characteristics at multiple scales from ocean basin to individual eddy. An evaluation by domain experts indicates that combining our feature-based techniques with illustrative visualization techniques provides an insight into the role eddies play in ocean circulation. A web-based GUI is under development to facilitate easy viewing of stored results. The GUI provides the user control to choose amongst available datasets, to specify the variables (such as temperature or salinity) to display on the isosurfaces, and to choose the scale and orientation of the view. These techniques allow an oceanographer to browse the data based on eddy paths and individual eddies rather than slices or volumes of data.

Development, Testing and Operation of a Large Suspended Ocean Measurement Structure for Deep-Ocean Use

DTIC Science & Technology

1992-05-01

and systems for developing , testing, and operating the system. A new, lightweight cable de- used this evolving technology base in the ensuing years...Funding Numbers. Development , Testing, and Operation of a Large Suspended Ocean Contrac Measurement Structure for Deep-Ocean Use Program Element No...Research L.aboratory Report Number. Ocean Acoutics and Technology Directorate PR 91:132:253 Stennis Space Center, MS 39529-5004 9. Sponsoring

Advancing coastal ocean modelling, analysis, and prediction for the US Integrated Ocean Observing System

USGS Publications Warehouse

Wilkin, John L.; Rosenfeld, Leslie; Allen, Arthur; Baltes, Rebecca; Baptista, Antonio; He, Ruoying; Hogan, Patrick; Kurapov, Alexander; Mehra, Avichal; Quintrell, Josie; Schwab, David; Signell, Richard; Smith, Jane

2017-01-01

This paper outlines strategies that would advance coastal ocean modelling, analysis and prediction as a complement to the observing and data management activities of the coastal components of the US Integrated Ocean Observing System (IOOS®) and the Global Ocean Observing System (GOOS). The views presented are the consensus of a group of US-based researchers with a cross-section of coastal oceanography and ocean modelling expertise and community representation drawn from Regional and US Federal partners in IOOS. Priorities for research and development are suggested that would enhance the value of IOOS observations through model-based synthesis, deliver better model-based information products, and assist the design, evaluation, and operation of the observing system itself. The proposed priorities are: model coupling, data assimilation, nearshore processes, cyberinfrastructure and model skill assessment, modelling for observing system design, evaluation and operation, ensemble prediction, and fast predictors. Approaches are suggested to accomplish substantial progress in a 3–8-year timeframe. In addition, the group proposes steps to promote collaboration between research and operations groups in Regional Associations, US Federal Agencies, and the international ocean research community in general that would foster coordination on scientific and technical issues, and strengthen federal–academic partnerships benefiting IOOS stakeholders and end users.

Atmospheric and ocean sensing with GNSS

NASA Technical Reports Server (NTRS)

Yunck, Thomas P.; Hajj, George A.

2003-01-01

The 1980s and 1990s saw the Global Positioning System (GPS) transform space geodesy from an elite national enterprise to one open to the individual researcher. By adapting the tools from that endeavor we are learning to probe the atmosphere and the ocean surface in novel ways, including ground-based sensing of atmospheric moisture; space-based profiling of atmospheric refractivity by active limb sounding; and global ocean altimetry with reflected signals.

Manufacturing Challenges and Benefits when Scaling the HIAD Stacked-Torus Aeroshell to a 15m-Class System

NASA Technical Reports Server (NTRS)

Swanson, Gregory; Cheatwood, Neil; Johnson, Keith; Calomino, Anthony; Gilles, Brian; Anderson, Paul; Bond, Bruce

2016-01-01

Over a decade of work has been conducted in the development of NASAs Hypersonic Inflatable Aerodynamic Decelerator (HIAD) deployable aeroshell technology. This effort has included multiple ground test campaigns and flight tests culminating in the HIAD projects second generation (Gen-2) aeroshell system. The HIAD project team has developed, fabricated, and tested stacked-torus inflatable structures (IS) with flexible thermal protection systems (F-TPS) ranging in diameters from 3-6m, with cone angles of 60 and 70 deg. To meet NASA and commercial near term objectives, the HIAD team must scale the current technology up to 12-15m in diameter. Therefore, the HIAD projects experience in scaling the technology has reached a critical juncture. Growing from a 6m to a 15m-class system will introduce many new structural and logistical challenges to an already complicated manufacturing process.Although the general architecture and key aspects of the HIAD design scale well to larger vehicles, details of the technology will need to be reevaluated and possibly redesigned for use in a 15m-class HIAD system. These include: layout and size of the structural webbing that transfers load throughout the IS, inflatable gas barrier design, torus diameter and braid construction, internal pressure and inflation line routing, adhesives used for coating and bonding, and F-TPS gore design and seam fabrication. The logistics of fabricating and testing the IS and the F-TPS also become more challenging with increased scale. Compared to the 6m aeroshell (the largest HIAD built to date), a 12m aeroshell has four times the cross-sectional area, and a 15m one has over six times the area. This means that fabrication and test procedures will need to be reexamined to ac-count for the sheer size and weight of the aeroshell components. This will affect a variety of steps in the manufacturing process, such as: stacking the tori during assembly, stitching the structural webbing, initial inflation of tori, and stitching of F-TPS gores. Additionally, new approaches and hardware will be required for handling and ground testing of both individual tori and the fully assembled HIADs.There are also noteworthy benefits of scaling up the HIAD aeroshell to a 15m-class system. Two complications in working with handmade textile structures are the non-linearity of the material components and the role of human accuracy during fabrication. Larger, more capable, HIAD structures should see much larger operational loads, potentially bringing the structural response of the material components out of the non-linear regime and into the preferred linear response range. Also, making the reasonable assumption that the magnitude of fabrication accuracy remains constant as the structures grow, the relative effect of fabrication errors should decrease as a percentage of the textile component size. Combined, these two effects improve the predictive capability and the uniformity of the structural response for a 12-15m HIAD.In this presentation, a handful of the challenges and associated mitigation plans will be discussed, as well as an update on current 12m aeroshell manufacturing and testing that is addressing these challenges

Manufacturing Challenges and Benefits When Scaling the HIAD Stacked-Torus Aeroshell to a 15 Meter Class System

NASA Technical Reports Server (NTRS)

Swanson, G. T.; Cheatwood, F. M.; Johnson, R. K.; Hughes, S. J.; Calomino, A. M.

2016-01-01

Over a decade of work has been conducted in the development of NASA's Hypersonic Inflatable Aerodynamic Decelerator (HIAD) deployable aeroshell technology. This effort has included multiple ground test campaigns and flight tests culminating in the HIAD project's second generation (Gen-2) aeroshell system. The HIAD project team has developed, fabricated, and tested stacked-torus inflatable structures (IS) with flexible thermal protection systems (F-TPS) ranging in diameters from 3-6 meters, with cone angles of 60 and 70 degrees. To meet NASA and commercial near-term objectives, the HIAD team must scale the current technology up to 12-15 meters in diameter. Therefore, the HIAD project's experience in scaling the technology has reached a critical juncture. Growing from a 6-meter to a 15-meter class system will introduce many new structural and logistical challenges to an already complicated manufacturing process. Although the general architecture and key aspects of the HIAD design scale well to larger vehicles, details of the technology will need to be reevaluated and possibly redesigned for use in a 15-meter-class HIAD system. These include: layout and size of the structural webbing that transfers load throughout the IS, inflatable gas barrier design, torus diameter and braid construction, internal pressure and inflation line routing, adhesives used for coating and bonding, and F-TPS gore design and seam fabrication. The logistics of fabricating and testing the IS and the F-TPS also become more challenging with increased scale. Compared to the 6-meter aeroshell (the largest HIAD built to date), a 12-meter aeroshell has four times the cross-sectional area, and a 15-meter one has over six times the area. This means that fabrication and test procedures will need to be reexamined to account for the sheer size and weight of the aeroshell components. This will affect a variety of steps in the manufacturing process, such as: stacking the tori during assembly, stitching the structural webbing, initial inflation of tori, and stitching of F-TPS gores. Additionally, new approaches and hardware will be required for handling and ground testing of both individual tori and the fully assembled HIADs. There are also noteworthy benefits of scaling up the HIAD aeroshell to a 15m-class system. Two complications in working with handmade textile structures are the non-linearity of the material components and the role of human accuracy during fabrication. Larger, more capable, HIAD structures should see much larger operational loads, potentially bringing the structural response of the material components out of the non-linear regime and into the preferred linear response range. Also, making the reasonable assumption that the magnitude of fabrication accuracy remains constant as the structures grow, the relative effect of fabrication errors should decrease as a percentage of the textile component size. Combined, these two effects improve the predictive capability and the uniformity of the structural response for a 12-15-meter HIAD. In this presentation, a handful of the challenges and associated mitigation plans will be discussed, as well as an update on current manufacturing and testing that addressing these challenges.

Manufacturing Challenges and Benefits when Scaling the HIAD Stacked-Torus Aeroshell to a 15m Class System

NASA Technical Reports Server (NTRS)

Cheatwood, F. McNeil; Swanson, Gregory T.; Johnson, R. Keith; Hughes, Stephen; Calomino, Anthony; Gilles, Brian; Anderson, Paul; Bond, Bruce

2016-01-01

Over a decade of work has been conducted in the development of NASA's Hypersonic Inflatable Aerodynamic Decelerator (HIAD) deployable aeroshell technology. This effort has included multiple ground test campaigns and flight tests culminating in the HIAD project's second generation (Gen-2) aeroshell system. The HIAD project team has developed, fabricated, and tested stacked-torus inflatable structures (IS) with flexible thermal protection systems (F-TPS) ranging in diameters from 3-6m, with cone angles of 60 and 70 deg. To meet NASA and commercial near term objectives, the HIAD team must scale the current technology up to 12-15m in diameter. The HIAD project's experience in scaling the technology has reached a critical juncture. Growing from a 6m to a 15m class system will introduce many new structural and logistical challenges to an already complicated manufacturing process. Although the general architecture and key aspects of the HIAD design scale well to larger vehicles, details of the technology will need to be reevaluated and possibly redesigned for use in a 15m-class HIAD system. These include: layout and size of the structural webbing that transfers load throughout the IS, inflatable gas barrier design, torus diameter and braid construction, internal pressure and inflation line routing, adhesives used for coating and bonding, and F-TPS gore design and seam fabrication. The logistics of fabricating and testing the IS and the F-TPS also become more challenging with increased scale. Compared to the 6m aeroshell (the largest HIAD built to date), a 12m aeroshell has four times the cross-sectional area, and a 15m one has over six times the area. This means that fabrication and test procedures will need to be reexamined to account for the sheer size and weight of the aeroshell components. This will affect a variety of steps in the manufacturing process, such as: stacking the tori during assembly, stitching the structural webbing, initial inflation of tori, and stitching of F-TPS gores. Additionally, new approaches and hardware will be required for handling and ground testing of both individual tori and the fully assembled HIADs. There are also noteworthy benefits of scaling up the HIAD aeroshell to 15m-class system. Two complications in working with handmade textiles structures are the non-linearity of the materials and the role of human accuracy during fabrication. Larger, more capable, HIAD structures should see much larger operational loads, potentially bringing the structural response of the materials out of the non-linear regime and into the preferred linear response range. Also, making the reasonable assumption that the magnitude of fabrication accuracy remains constant as the structures grow, the relative effect of fabrication errors should decrease as a percentage of the textile component size. Combined, these two effects improve the predictive capability and the uniformity of the structural response for a 12-15m class HIAD. In this paper, the challenges and associated mitigation plans related to scaling up the HIAD stacked-torus aeroshell to a 15m class system will be discussed. In addition, the benefits of enlarging the structure will be further explored.

Three-dimensional ocean sensor networks: A survey

NASA Astrophysics Data System (ADS)

Wang, Yu; Liu, Yingjian; Guo, Zhongwen

2012-12-01

The past decade has seen a growing interest in ocean sensor networks because of their wide applications in marine research, oceanography, ocean monitoring, offshore exploration, and defense or homeland security. Ocean sensor networks are generally formed with various ocean sensors, autonomous underwater vehicles, surface stations, and research vessels. To make ocean sensor network applications viable, efficient communication among all devices and components is crucial. Due to the unique characteristics of underwater acoustic channels and the complex deployment environment in three dimensional (3D) ocean spaces, new efficient and reliable communication and networking protocols are needed in design of ocean sensor networks. In this paper, we aim to provide an overview of the most recent advances in network design principles for 3D ocean sensor networks, with focuses on deployment, localization, topology design, and position-based routing in 3D ocean spaces.

75 FR 26100 - Danger Zone, Pacific Ocean, Naval Base Coronado, Coronado, California

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

..., Pacific Ocean, Naval Base Coronado, Coronado, California AGENCY: U.S. Army Corps of Engineers, DoD. ACTION... Naval Base Coronado (NBC), in Coronado, San Diego County, California. The danger zone will provide..., Naval Base Coronado (NBC), has requested that the Corps establish a danger zone in the waters of the...

Development of a new model for short period ocean tidal variations of Earth rotation

NASA Astrophysics Data System (ADS)

Schuh, Harald

2015-08-01

Within project SPOT (Short Period Ocean Tidal variations in Earth rotation) we develop a new high frequency Earth rotation model based on empirical ocean tide models. The main purpose of the SPOT model is its application to space geodetic observations such as GNSS and VLBI.We consider an empirical ocean tide model, which does not require hydrodynamic ocean modeling to determine ocean tidal angular momentum. We use here the EOT11a model of Savcenko & Bosch (2012), which is extended for some additional minor tides (e.g. M1, J1, T2). As empirical tidal models do not provide ocean tidal currents, which are re- quired for the computation of oceanic relative angular momentum, we implement an approach first published by Ray (2001) to estimate ocean tidal current veloci- ties for all tides considered in the extended EOT11a model. The approach itself is tested by application to tidal heights from hydrodynamic ocean tide models, which also provide tidal current velocities. Based on the tidal heights and the associated current velocities the oceanic tidal angular momentum (OTAM) is calculated.For the computation of the related short period variation of Earth rotation, we have re-examined the Euler-Liouville equation for an elastic Earth model with a liquid core. The focus here is on the consistent calculation of the elastic Love num- bers and associated Earth model parameters, which are considered in the Euler- Liouville equation for diurnal and sub-diurnal periods in the frequency domain.

Ocean (de)oxygenation from the Last Glacial Maximum to the twenty-first century: insights from Earth System models.

PubMed

Bopp, L; Resplandy, L; Untersee, A; Le Mezo, P; Kageyama, M

2017-09-13

All Earth System models project a consistent decrease in the oxygen content of oceans for the coming decades because of ocean warming, reduced ventilation and increased stratification. But large uncertainties for these future projections of ocean deoxygenation remain for the subsurface tropical oceans where the major oxygen minimum zones are located. Here, we combine global warming projections, model-based estimates of natural short-term variability, as well as data and model estimates of the Last Glacial Maximum (LGM) ocean oxygenation to gain some insights into the major mechanisms of oxygenation changes across these different time scales. We show that the primary uncertainty on future ocean deoxygenation in the subsurface tropical oceans is in fact controlled by a robust compensation between decreasing oxygen saturation (O 2sat ) due to warming and decreasing apparent oxygen utilization (AOU) due to increased ventilation of the corresponding water masses. Modelled short-term natural variability in subsurface oxygen levels also reveals a compensation between O 2sat and AOU, controlled by the latter. Finally, using a model simulation of the LGM, reproducing data-based reconstructions of past ocean (de)oxygenation, we show that the deoxygenation trend of the subsurface ocean during deglaciation was controlled by a combination of warming-induced decreasing O 2sat and increasing AOU driven by a reduced ventilation of tropical subsurface waters.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Author(s).

Ocean (de)oxygenation from the Last Glacial Maximum to the twenty-first century: insights from Earth System models

NASA Astrophysics Data System (ADS)

Bopp, L.; Resplandy, L.; Untersee, A.; Le Mezo, P.; Kageyama, M.

2017-08-01

All Earth System models project a consistent decrease in the oxygen content of oceans for the coming decades because of ocean warming, reduced ventilation and increased stratification. But large uncertainties for these future projections of ocean deoxygenation remain for the subsurface tropical oceans where the major oxygen minimum zones are located. Here, we combine global warming projections, model-based estimates of natural short-term variability, as well as data and model estimates of the Last Glacial Maximum (LGM) ocean oxygenation to gain some insights into the major mechanisms of oxygenation changes across these different time scales. We show that the primary uncertainty on future ocean deoxygenation in the subsurface tropical oceans is in fact controlled by a robust compensation between decreasing oxygen saturation (O2sat) due to warming and decreasing apparent oxygen utilization (AOU) due to increased ventilation of the corresponding water masses. Modelled short-term natural variability in subsurface oxygen levels also reveals a compensation between O2sat and AOU, controlled by the latter. Finally, using a model simulation of the LGM, reproducing data-based reconstructions of past ocean (de)oxygenation, we show that the deoxygenation trend of the subsurface ocean during deglaciation was controlled by a combination of warming-induced decreasing O2sat and increasing AOU driven by a reduced ventilation of tropical subsurface waters. This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

Statistical and dynamical assessment of land-ocean-atmosphere interactions across North Africa

NASA Astrophysics Data System (ADS)

Yu, Yan

North Africa is highly vulnerable to hydrologic variability and extremes, including impacts of climate change. The current understanding of oceanic versus terrestrial drivers of North African droughts and pluvials is largely model-based, with vast disagreement among models in terms of the simulated oceanic impacts and vegetation feedbacks. Regarding oceanic impacts, the relative importance of the tropical Pacific, tropical Indian, and tropical Atlantic Oceans in regulating the North African rainfall variability, as well as the underlying mechanism, remains debated among different modeling studies. Classic theory of land-atmosphere interactions across the Sahel ecotone, largely based on climate modeling experiments, has promoted positive vegetation-rainfall feedbacks associated with a dominant surface albedo mechanism. However, neither the proposed positive vegetation-rainfall feedback with its underlying albedo mechanism, nor its relative importance compared with oceanic drivers, has been convincingly demonstrated up to now using observational data. Here, the multivariate Generalized Equilibrium Feedback Assessment (GEFA) is applied in order to identify the observed oceanic and terrestrial drivers of North African climate and quantify their impacts. The reliability of the statistical GEFA method is first evaluated against dynamical experiments within the Community Earth System Model (CESM). In order to reduce the sampling error caused by short data records, the traditional GEFA approach is refined through stepwise GEFA, in which unimportant forcings are dropped through stepwise selection. In order to evaluate GEFA's reliability in capturing oceanic impacts, the atmospheric response to a sea-surface temperature (SST) forcing across the tropical Pacific, tropical Indian, and tropical Atlantic Ocean is estimated independently through ensembles of dynamical experiments and compared with GEFA-based assessments. Furthermore, GEFA's performance in capturing terrestrial impacts is evaluated through ensembles of fully coupled CESM dynamical experiments, with modified leaf area index (LAI) and soil moisture across the Sahel or West African Monsoon (WAM) region. The atmospheric responses to oceanic and terrestrial forcings are generally consistent between the dynamical experiments and statistical GEFA, confirming GEFA's capability of isolating the individual impacts of oceanic and terrestrial forcings on North African climate. Furthermore, with the incorporation of stepwise selection, GEFA can now provide reliable estimates of the oceanic and terrestrial impacts on the North African climate with the typical length of observational datasets, thereby enhancing the method's applicability. After the successful validation of GEFA, the key observed oceanic and terrestrial drivers of North African climate are identified through the application of GEFA to gridded observations, remote sensing products, and reanalyses. According to GEFA, oceanic drivers dominate over terrestrial drivers in terms of their observed impacts on North African climate in most seasons. Terrestrial impacts are comparable to, or more important than, oceanic impacts on rainfall during the post-monsoon across the Sahel and WAM region, and after the short rain across the Horn of Africa (HOA). The key ocean basins that regulate North African rainfall are typically located in the tropics. While the observed impacts of SST variability across the tropical Pacific and tropical Atlantic Oceans on the Sahel rainfall are largely consistent with previous model-based findings, minimal impacts from tropical Indian Ocean variability on Sahel rainfall are identified in observations, in contrast to previous modeling studies. The current observational analysis verifies model-hypothesized positive vegetation-rainfall feedback across the Sahel and HOA, which is confined to the post-monsoon and post-short rains season, respectively. However, the observed positive vegetation feedback to rainfall in the semi-arid Sahel and HOA is largely due to moisture recycling, rather than the classic albedo mechanism. Future projections of Sahel rainfall remain highly uncertain in terms of both sign and magnitude within phases three and five of the Coupled Model Intercomparison Project (CMIP3 and CMIP5). The GEFA-based observational analyses will provide a benchmark for evaluating climate models, which will facilitate effective process-based model weighting for more reliable projections of regional climate, as well as model development.

Research on strategy marine noise map based on i4ocean platform: Constructing flow and key approach

NASA Astrophysics Data System (ADS)

Huang, Baoxiang; Chen, Ge; Han, Yong

2016-02-01

Noise level in a marine environment has raised extensive concern in the scientific community. The research is carried out on i4Ocean platform following the process of ocean noise model integrating, noise data extracting, processing, visualizing, and interpreting, ocean noise map constructing and publishing. For the convenience of numerical computation, based on the characteristics of ocean noise field, a hybrid model related to spatial locations is suggested in the propagation model. The normal mode method K/I model is used for far field and ray method CANARY model is used for near field. Visualizing marine ambient noise data is critical to understanding and predicting marine noise for relevant decision making. Marine noise map can be constructed on virtual ocean scene. The systematic marine noise visualization framework includes preprocessing, coordinate transformation interpolation, and rendering. The simulation of ocean noise depends on realistic surface. Then the dynamic water simulation gird was improved with GPU fusion to achieve seamless combination with the visualization result of ocean noise. At the same time, the profile and spherical visualization include space, and time dimensionality were also provided for the vertical field characteristics of ocean ambient noise. Finally, marine noise map can be published with grid pre-processing and multistage cache technology to better serve the public.

The effect of the MJO on the energetics of El Niño

NASA Astrophysics Data System (ADS)

Lybarger, Nicholas D.; Stan, Cristiana

2017-12-01

The energy budget of the Pacific Ocean is evaluated in the Super-Parameterized Community Climate Model version 4 (SP-CCSM4) on intraseasonal time scales. The budget terms are decomposed to isolate the MJO influence and the ocean current associated with Kelvin waves. Using this decomposition, one can distinguish between El Niño events with strong and weak MJO influence. Composites of El Niño events based on the wind power component associated with the MJO induced wind stress and oceanic Kelvin waves ({{W}_{{MJO},{K}}} ) are compared with composites based only on the atmospheric variability and based only on the oceanic variability. It was found that the composite of events when {{W}_{{MJO},{K}}} is near maximum (+ NMJO,K) shows a greater magnitude of mean perturbation wind power, buoyancy power, and available potential energy than any other case, which is consistent with the greater amplitude Kelvin wave perturbations on the thermocline, as well as the greater amplitude of SST anomalies at the peak of the event. For + NMJO,K, latent heat flux anomalies out of the ocean along the coast of New Guinea are seen coincident with deepening of the mixed layer depth there, suggesting that this is an important region for the thermodynamic influence of the MJO on the ocean. Latent heat flux anomalies into the ocean are seen across the ITCZ in the spring, suggesting a basin wide influence by the MJO on the ocean surface radiation budget in + NMJO,K.

On the use of Schwarz-Christoffel conformal mappings to the grid generation for global ocean models

NASA Astrophysics Data System (ADS)

Xu, S.; Wang, B.; Liu, J.

2015-02-01

In this article we propose two conformal mapping based grid generation algorithms for global ocean general circulation models (OGCMs). Contrary to conventional, analytical forms based dipolar or tripolar grids, the new algorithms are based on Schwarz-Christoffel (SC) conformal mapping with prescribed boundary information. While dealing with the basic grid design problem of pole relocation, these new algorithms also address more advanced issues such as smoothed scaling factor, or the new requirements on OGCM grids arisen from the recent trend of high-resolution and multi-scale modeling. The proposed grid generation algorithm could potentially achieve the alignment of grid lines to coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the generated grids are still orthogonal curvilinear, they can be readily utilized in existing Bryan-Cox-Semtner type ocean models. The proposed methodology can also be applied to the grid generation task for regional ocean modeling where complex land-ocean distribution is present.

Structural testing and analysis of a braided, inflatable fabric torus structure

NASA Astrophysics Data System (ADS)

Young, Andrew C.; Davids, William G.; Whitney, Daniel J.; Clapp, Joshua D.; Goupee, Andrew J.

2017-10-01

Inflatable structural members have military, disaster relief, aerospace and other important applications as they possess low mass, can be stored in a relatively small volume and have significant load-carrying capacity once pressurized. Of particular interest to the present research is the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) structure under development by NASA. In order to make predictions about the structural response of the HIAD system, it is necessary to understand the response of individual inflatable tori composing the HIAD structure. These inflatable members present unique challenges to structural testing and modeling due to their internal inflation pressure and relative compliance. Structural testing was performed on a braided, inflatable, toroidal structural member with axial reinforcing cords. The internal inflation pressure, magnitude of enforced displacement and loading methodology were varied. In-plane and out-of-plane experimental results were compared to model predictions using a three dimensional, corotational, flexibility-based fiber-beam finite element model including geometric and material nonlinearities, as well as the effects of inflation pressure. It was found that in order to approximate the load-deformation response observed in experimentation it is necessary to carefully control the test and model boundary conditions and loading scheme.

Potential of plant polyphenols to combat oxidative stress and inflammatory processes in farm animals.

PubMed

Gessner, D K; Ringseis, R; Eder, K

2017-08-01

Polyphenols are secondary plant metabolites which have been shown to exert antioxidative and antiinflamma tory effects in cell culture, rodent and human studies. Based on the fact that conditions of oxidative stress and inflammation are highly relevant in farm animals, polyphenols are considered as promising feed additives in the nutrition of farm animals. However, in contrast to many studies existing with model animals and humans, potential antioxidative and antiinflammatory effects of polyphenols have been less investigated in farm animals so far. This review aims to give an overview about potential antioxidative and antiinflammatory effects in farm animals. The first part of the review highlights the occurrence and the consequences of oxidative stress and inflammation on animal health and performance. The second part of the review deals with bioavailability and metabolism of polyphenols in farm animals. The third and main part of the review presents an overview of the findings from studies which investigated the effects of polyphenols of various plant sources in pigs, poultry and cattle, with particular consideration of effects on the antioxidant system and inflammation. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz

We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituentmore » of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.« less

Ocean products delivered by the Mercator Ocean Service Department

NASA Astrophysics Data System (ADS)

Crosnier, L.; Durand, E.; Soulat, F.; Messal, F.; Buarque, S.; Toumazou, V.; Landes, V.; Drevillon, M.; Lellouche, J.

2008-12-01

The newly created Service Department at Mercator Ocean is now offering various services for academic and private ocean applications. Mercator Ocean runs operationally ocean forecast systems for the Global and North Atlantic Ocean. These systems are based on an ocean general circulation model NEMO as well as on data assimilation of sea level anomalies, sea surface temperature and temperature and salinity vertical profiles. Three dimensional ocean fields of temperature, salinity and currents are updated and available weekly, including analysis and 2 weeks forecast fields. The Mercator Ocean service department is now offering a wide range of ocean derived products. This presentation will display some of the various products delivered in the framework of academic and private ocean applications: " Monitoring of the ocean current at the surface and at depth in several geographical areas for offshore oil platform, for offshore satellite launch platform, for transatlantic sailing or rowing boat races. " Monitoring of ocean climate indicators (Coral bleaching...) for marine reserve survey; " Monitoring of upwelling systems for fisheries; " Monitoring of the ocean heat content for tropical cyclone monitoring. " Monitoring of the ocean temperature/salinity and currents to guide research vessels during scientific cruises. The Mercator Ocean products catalogue will grow wider in the coming years, especially in the framework of the European GMES MyOcean project (FP7).

PYROTRON WITH TRANSLATIONAL CLOSURE FIELDS

DOEpatents

Hartwig, E.C.; Cummings, D.B.; Post, R.F.

1962-01-01

Circuit means is described for effecting inward transla- ' tory motion of the intensified terminal reflector field regions of a magnetic mirror plasma containment field with a simultaneous intensification of the over-all field configuration. The circuit includes a segmented magnetic field generating solenoid and sequentially actuated switch means to consecutively short-circuit the solenoid segments and place charged capacitor banks in shunt with the segments in an appropriate correlated sequence such that electrical energy is transferred inwardly between adjacent segments from the opposite ends of the solenoid. The resulting magnetic field is effective in both radially and axially adiabatically compressing a plasma in a reaction chamber disposed concentrically within the solenoid. In addition, one half of the circuit may be employed to unidirectionally accelerate plasma. (AEC)

Interactions of vortices with a flexible beam with applications in fluidic energy harvesting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goushcha, O.; Elvin, N.; Andreopoulos, Y.

2014-01-13

A cantilever piezoelectric beam immersed in a flow and subjected to naturally occurring vortices such as those formed in the wake of bluff bodies can be used to generate electrical energy harvested in fluid flows. In this paper, we present the pressure distribution and deflection of a piezoelectric beam subjected to controlled vortices. A custom designed experimental facility is set up to study the interaction of individual and multiple vortices with the beam. Vortex tori are generated by an audio speaker and travel at controlled rates over the beam. Particle image velocimetry is used to measure the 2-D flow fieldmore » induced by each vortex and estimate the effect of pressure force on the beam deflection.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaing, K. C.; Peng, Yueng Kay Martin

Transport theory for potato orbits in the region near the magnetic axis in an axisymmetric torus such as tokamaks and spherical tori is extended to the situation where the toroidal flow speed is of the order of the sonic speed as observed in National Spherical Torus Experiment [E. J. Synakowski, M. G. Bell, R. E. Bell et al., Nucl. Fusion 43, 1653 (2003)]. It is found that transport fluxes such as ion radial heat flux, and bootstrap current density are modified by a factor of the order of the square of the toroidal Mach number. The consequences of the orbitmore » squeezing are also presented. The theory is developed for parabolic (in radius r) plasma profiles. A method to apply the results of the theory for the transport modeling is discussed.« less

Dynamics and formation of obscuring tori in AGNs

NASA Astrophysics Data System (ADS)

Bannikova, Elena Yu.; Sergeyev, Alexey V.

2017-12-01

We considered the evolution of a self-gravitating clumpy torus in the gravitational field of the central mass of an active galactic nucleus (AGN) in the framework of the N-body problem. The initial conditions take into account winds with different opening angles. Results of our N-body simulations show that the clouds moving on orbits with a spread in inclinations and eccentricities form a toroidal region. This mechanism can solve the problem of the geometrical thickness of the torus. The velocity of the clouds at the inner edge of the torus is lower than in a disk model that can explain the observed rotation curves. We discuss the scenario of torus formation related with the beginning of the AGN stage.

Orbital ATK CRS-7 Launch Coverage

NASA Image and Video Library

2017-04-18

NASA Television conducted a live broadcast from Kennedy Space Center as Orbital ATK’s CRS-7 lifted off atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. Orbital ATK’s Cygnus spacecraft carried more than 7,600 pounds of science research, crew supplies, and hardware to the orbiting laboratory as Orbital ATK’s seventh commercial resupply services mission to the International Space Station. Launch commentary conducted by: -George Diller, NASA Communications Special guests included: -Frank DeMauro, VP & GM, Advanced Programs Division, Space Systems Group, Orbital ATK -Tori McLendon, NASA Communications -Robert Cabana, Kennedy Space Center Director -Tara Ruttley, Associate Program Scientist, International Space Station -Vern Thorp, Program Manager for Commercial Missions, United Launch Alliance

Studies of the gas tori of Titan and Triton

NASA Technical Reports Server (NTRS)

Smyth, William H.

1995-01-01

Progress in the development of the model for the circumplanetary distribution of atomic hydrogen in the Saturn system produced by a Titan source is discussed. Because of the action of the solar radiation acceleration and the obliquity of Saturn, the hydrogen distribution is shown to undergo seasonal changes as the planet moves about the Sun. Preliminary model calculations show that for a continuous Titan source, the H distribution is highly asymmetric about the planet and has a density maximum near the dusk side of Saturn, qualitatively similar to the pattern recently deduced by Shemansky and Hall from observations acquired by the UVS instruments aboard the Voyager spacecrafts. The investigation of these Voyager data will be undertaken in the next project year.

Singularity and stability in a periodic system of particle accelerators

NASA Astrophysics Data System (ADS)

Cai, Yunhai

2018-05-01

We study the single-particle dynamics in a general and parametrized alternating-gradient cell with zero chromaticity using the Lie algebra method. To our surprise, the first-order perturbation of the sextupoles largely determines the dynamics away from the major resonances. The dynamic aperture can be estimated from the topology and geometry of the phase space. In the linearly normalized phase space, it is scaled according to A ¯ ∝ϕ √{L } , where ϕ is the bending angle and L the length of the cell. For the 2 degrees of freedom with equal betatron tunes, the analytical perturbation theory leads us to the invariant or quasi-invariant tori, which play an important role in determining the stable volume in the four-dimensional phase space.

The influence of meridional ice transport on Europa's ocean stratification and heat content

NASA Astrophysics Data System (ADS)

Zhu, Peiyun; Manucharyan, Georgy E.; Thompson, Andrew F.; Goodman, Jason C.; Vance, Steven D.

2017-06-01

Jupiter's moon Europa likely hosts a saltwater ocean beneath its icy surface. Geothermal heating and rotating convection in the ocean may drive a global overturning circulation that redistributes heat vertically and meridionally, preferentially warming the ice shell at the equator. Here we assess the previously unconstrained influence of ocean-ice coupling on Europa's ocean stratification and heat transport. We demonstrate that a relatively fresh layer can form at the ice-ocean interface due to a meridional ice transport forced by the differential ice shell heating between the equator and the poles. We provide analytical and numerical solutions for the layer's characteristics, highlighting their sensitivity to critical ocean parameters. For a weakly turbulent and highly saline ocean, a strong buoyancy gradient at the base of the freshwater layer can suppress vertical tracer exchange with the deeper ocean. As a result, the freshwater layer permits relatively warm deep ocean temperatures.

The influence of meridional ice transport on Europa's ocean stratification and heat content

NASA Astrophysics Data System (ADS)

Zhu, P.; Manucharyan, G.; Thompson, A. F.; Goodman, J. C.; Vance, S.

2017-12-01

Jupiter's moon Europa likely hosts a saltwater ocean beneath its icy surface. Geothermal heating and rotating convection in the ocean may drive a global overturning circulation that redistributes heat vertically and meridionally, preferentially warming the ice shell at the equator. Here we assess thepreviously unconstrained influence of ocean-ice coupling on Europa's ocean stratification and heat transport. We demonstrate that a relatively fresh layer can form at the ice-ocean interface due to a meridional ice transport forced by the differential ice shell heating between the equator and the poles. We provide analytical and numerical solutions for the layer's characteristics, highlighting their sensitivity to critical ocean parameters. For a weakly turbulent and highly saline ocean, a strong buoyancy gradient at the base of the freshwater layer can suppress vertical tracer exchange with the deeper ocean. As a result, the freshwater layer permits relatively warm deep ocean temperatures.

Average intensity and coherence properties of a partially coherent Lorentz-Gauss beam propagating through oceanic turbulence

NASA Astrophysics Data System (ADS)

Liu, Dajun; Wang, Guiqiu; Wang, Yaochuan

2018-01-01

Based on the Huygens-Fresnel integral and the relationship of Lorentz distribution and Hermite-Gauss function, the average intensity and coherence properties of a partially coherent Lorentz-Gauss beam propagating through oceanic turbulence have been investigated by using numerical examples. The influences of beam parameters and oceanic turbulence on the propagation properties are also discussed in details. It is shown that the partially coherent Lorentz-Gauss beam with smaller coherence length will spread faster in oceanic turbulence, and the stronger oceanic turbulence will accelerate the spreading of partially coherent Lorentz-Gauss beam in oceanic turbulence.

A 600-ka Arctic sea-ice record from Mendeleev Ridge based on ostracodes

USGS Publications Warehouse

Cronin, Thomas M.; Polyak, L.V.; Reed, D.; Kandiano, E. S.; Marzen, R. E.; Council, E. A.

2013-01-01

Arctic paleoceanography and sea-ice history were reconstructed from epipelagic and benthic ostracodes from a sediment core (HLY0503-06JPC, 800 m water depth) located on the Mendeleev Ridge, Western Arctic Ocean. The calcareous microfaunal record (ostracodes and foraminifers) covers several glacial/interglacial cycles back to estimated Marine Isotope Stage 13 (MIS 13, ∼500 ka) with an average sedimentation rate of ∼0.5 cm/ka for most of the stratigraphy (MIS 5–13). Results based on ostracode assemblages and an unusual planktic foraminiferal assemblage in MIS 11 dominated by a temperate-water species Turborotalita egelida show that extreme interglacial warmth, high surface ocean productivity, and possibly open ocean convection characterized MIS 11 and MIS 13 (∼400 and 500 ka, respectively). A major shift in western Arctic Ocean environments toward perennial sea ice occurred after MIS 11 based on the distribution of an ice-dwelling ostracode Acetabulastoma arcticum. Spectral analyses of the ostracode assemblages indicate sea ice and mid-depth ocean circulation in western Arctic Ocean varied primarily at precessional (∼22 ka) and obliquity (∼40 ka) frequencies.

The role of internal variability for decadal carbon uptake anomalies in the Southern Ocean

NASA Astrophysics Data System (ADS)

Spring, Aaron; Hi, Hongmei; Ilyina, Tatiana

2017-04-01

The Southern Ocean is a major sink for anthropogenic CO2 emissions and hence it plays an essential role in modulating global carbon cycle and climate change. Previous studies based on observations (e.g., Landschützer et al. 2015) show pronounced decadal variations of carbon uptake in the Southern Ocean in recent decades and this variability is largely driven by internal climate variability. However, due to limited ensemble size of simulations, the variability of this important ocean sink is still poorly assessed by the state-of-the-art earth system models (ESMs). To assess the internal variability of carbon sink in the Southern Ocean, we use a large ensemble of 100 member simulations based on the Max Planck Institute-ESM (MPI-ESM). The large ensemble of simulations is generated via perturbed initial conditions in the ocean and atmosphere. Each ensemble member includes a historical simulation from 1850 to 2005 with an extension until 2100 under Representative Concentration Pathway (RCP) 4.5 future projections. Here we use model simulations from 1980-2015 to compare with available observation-based dataset. We found several ensemble members showing decadal decreasing trends in the carbon sink, which are similar to the trend shown in observations. This result suggests that MPI-ESM large ensemble simulations are able to reproduce decadal variation of carbon sink in the Southern Ocean. Moreover, the decreasing trends of Southern Ocean carbon sink in MPI-ESM are mainly contributed by region between 50-60°S. To understand the internal variability of the air-sea carbon fluxes in the Southern Ocean, we further investigate the variability of underlying processes, such as physical climate variability and ocean biological processes. Our results indicate two main drivers for the decadal decreasing trend of carbon sink: i) Intensified winds enhance upwelling of old carbon-rich waters, this leads to increase of the ocean surface pCO2; ii) Primary production is reduced in area from 50-60°S, probably induced by reduced euphotic water column stability; therefore the biological drawdown of ocean surface pCO2 is weakened accordingly and hence the ocean is in favor of carbon outgassing. Landschützer, et al. (2015): The reinvigoration of the Southern Ocean carbon sink, Science, 349, 1221-1224.

Exploring the southern ocean response to climate change

NASA Technical Reports Server (NTRS)

Martinson, Douglas G.; Rind, David; Parkinson, Claire

1993-01-01

The purpose of this project was to couple a regional (Southern Ocean) ocean/sea ice model to the existing Goddard Institute for Space Science (GISS) atmospheric general circulation model (GCM). This modification recognizes: the relative isolation of the Southern Ocean; the need to account, prognostically, for the significant air/sea/ice interaction through all involved components; and the advantage of translating the atmospheric lower boundary (typically the rapidly changing ocean surface) to a level that is consistent with the physical response times governing the system evolution (that is, to the base of the fast responding ocean surface layer). The deeper ocean beneath this layer varies on time scales several orders of magnitude slower than the atmosphere and surface ocean, and therefore the boundary between the upper and deep ocean represents a more reasonable fixed boundary condition.

Liquid Water Oceans in Ice Giants

NASA Technical Reports Server (NTRS)

Wiktorowicz, Sloane J.; Ingersoll, Andrew P.

2007-01-01

Aptly named, ice giants such as Uranus and Neptune contain significant amounts of water. While this water cannot be present near the cloud tops, it must be abundant in the deep interior. We investigate the likelihood of a liquid water ocean existing in the hydrogen-rich region between the cloud tops and deep interior. Starting from an assumed temperature at a given upper tropospheric pressure (the photosphere), we follow a moist adiabat downward. The mixing ratio of water to hydrogen in the gas phase is small in the photosphere and increases with depth. The mixing ratio in the condensed phase is near unity in the photosphere and decreases with depth; this gives two possible outcomes. If at some pressure level the mixing ratio of water in the gas phase is equal to that in the deep interior, then that level is the cloud base. The gas below the cloud base has constant mixing ratio. Alternately, if the mixing ratio of water in the condensed phase reaches that in the deep interior, then the surface of a liquid ocean will occur. Below this ocean surface, the mixing ratio of water will be constant. A cloud base occurs when the photospheric temperature is high. For a family of ice giants with different photospheric temperatures, the cooler ice giants will have warmer cloud bases. For an ice giant with a cool enough photospheric temperature, the cloud base will exist at the critical temperature. For still cooler ice giants, ocean surfaces will result. A high mixing ratio of water in the deep interior favors a liquid ocean. We find that Neptune is both too warm (photospheric temperature too high) and too dry (mixing ratio of water in the deep interior too low) for liquid oceans to exist at present. To have a liquid ocean, Neptune s deep interior water to gas ratio would have to be higher than current models allow, and the density at 19 kbar would have to be approx. equal to 0.8 g/cu cm. Such a high density is inconsistent with gravitational data obtained during the Voyager flyby. In our model, Neptune s water cloud base occurs around 660 K and 11 kbar, and the density there is consistent with Voyager gravitational data. As Neptune cools, the probability of a liquid ocean increases. Extrasolar "hot Neptunes," which presumably migrate inward toward their parent stars, cannot harbor liquid water oceans unless they have lost almost all of the hydrogen and helium from their deep interiors.

Anomalous Structure of Oceanic Lithosphere in the North Atlantic and Arctic Oceans: A Preliminary Analysis Based on Bathymetry, Gravity and Crustal Structure

NASA Astrophysics Data System (ADS)

Barantsrva, O.

2014-12-01

We present a preliminary analysis of the crustal and upper mantle structure for off-shore regions in the North Atlantic and Arctic oceans. These regions have anomalous oceanic lithosphere: the upper mantle of the North Atlantic ocean is affected by the Iceland plume, while the Arctic ocean has some of the slowest spreading rates. Our specific goal is to constrain the density structure of the upper mantle in order to understand the links between the deep lithosphere dynamics, ocean spreading, ocean floor bathymetry, heat flow and structure of the oceanic lithosphere in the regions where classical models of evolution of the oceanic lithosphere may not be valid. The major focus is on the oceanic lithosphere, but the Arctic shelves with a sufficient data coverage are also included into the analysis. Out major interest is the density structure of the upper mantle, and the analysis is based on the interpretation of GOCE satellite gravity data. To separate gravity anomalies caused by subcrustal anomalous masses, the gravitational effect of water, crust and the deep mantle is removed from the observed gravity field. For bathymetry we use the global NOAA database ETOPO1. The crustal correction to gravity is based on two crustal models: (1) global model CRUST1.0 (Laske, 2013) and, for a comparison, (2) a regional seismic model EUNAseis (Artemieva and Thybo, 2013). The crustal density structure required for the crustal correction is constrained from Vp data. Previous studies have shown that a large range of density values corresponds to any Vp value. To overcome this problem and to reduce uncertainty associated with the velocity-density conversion, we account for regional tectonic variations in the Northern Atlantics as constrained by numerous published seismic profiles and potential-field models across the Norwegian off-shore crust (e.g. Breivik et al., 2005, 2007), and apply different Vp-density conversions for different parts of the region. We present preliminary results, which we use to examine factors that control variations in bathymetry, sedimentary and crustal thicknesses in these anomalous oceanic domains.

A comparison of chemical compositions of reported altered oceanic crusts and global MORB data set: implication for isotopic heterogeneity of recycled materials

NASA Astrophysics Data System (ADS)

Shimoda, G.; Kogiso, T.

2017-12-01

Chemical composition of altered oceanic crust is one of important constraints to delineate chemical heterogeneity of the mantle. Accordingly, many researchers have been studied to determine bulk chemical composition of altered oceanic crust mainly based on chemical compositions of old oceanic crusts at Site 801 and Site 417/418, and young crust at Site 504 (e.g., Staudigel et al., 1996; Bach et al. 2003; Kuo et al., 2016). Their careful estimation provided reliable bulk chemical compositions of these Sites and revealed common geochemical feature of alteration. To assess effect of recycling of altered oceanic crust on chemical evolution of the mantle, it might be meaningful to discuss whether the reported chemical compositions of altered oceanic crusts can represent chemical composition of globally subducted oceanic crusts. Reported chemical compositions of fresh glass or less altered samples from Site 801, 417/418 and 504 were highly depleted compared to that of global MORB reported by Gale et al. (2013), suggesting that there might be sampling bias. Hence, it could be important to consider chemical difference between oceanic crusts of these three Sites and global MORB to discuss effect of recycling of oceanic crust on isotopic heterogeneity of the mantle. It has been suggested that one of controlling factors of chemical variation of oceanic crust is crustal spreading rate because different degree of partial melting affects chemical composition of magmas produced at a mid-ocean ridge. Crustal spreading rate could also affect intensity of alteration. Namely, oceanic crusts produced at slow-spreading ridges may prone to be altered due to existence of larger displacement faults compared to fast spreading ridges which have relatively smooth topography. Thus, it might be significant to evaluate isotopic evolution of oceanic crusts those were produced at different spreading rates. In this presentation, we will provide a possible chemical variation of altered oceanic crusts based on reported bulk chemical compositions of altered oceanic crusts and global data sets of MORB. On the basis of the chemical variation, we will discuss isotopic evolution of altered oceanic crusts to delineate isotopic variation of recycled oceanic crusts.

Ocean Wave Simulation Based on Wind Field

PubMed Central

2016-01-01

Ocean wave simulation has a wide range of applications in movies, video games and training systems. Wind force is the main energy resource for generating ocean waves, which are the result of the interaction between wind and the ocean surface. While numerous methods to handle simulating oceans and other fluid phenomena have undergone rapid development during the past years in the field of computer graphic, few of them consider to construct ocean surface height field from the perspective of wind force driving ocean waves. We introduce wind force to the construction of the ocean surface height field through applying wind field data and wind-driven wave particles. Continual and realistic ocean waves result from the overlap of wind-driven wave particles, and a strategy was proposed to control these discrete wave particles and simulate an endless ocean surface. The results showed that the new method is capable of obtaining a realistic ocean scene under the influence of wind fields at real time rates. PMID:26808718

The tongue of the ocean as a remote sensing ocean color calibration range

NASA Technical Reports Server (NTRS)

Strees, L. V.

1972-01-01

In general, terrestrial scenes remain stable in content from both temporal and spacial considerations. Ocean scenes, on the other hand, are constantly changing in content and position. The solar energy that enters the ocean waters undergoes a process of scattering and selective spectral absorption. Ocean scenes are thus characterized as low level radiance with the major portion of the energy in the blue region of the spectrum. Terrestrial scenes are typically of high level radiance with their spectral energies concentrated in the green-red regions of the visible spectrum. It appears that for the evaluation and calibration of ocean color remote sensing instrumentation, an ocean area whose optical ocean and atmospheric properties are known and remain seasonably stable over extended time periods is needed. The Tongue of the Ocean, a major submarine channel in the Bahama Banks, is one ocean are for which a large data base of oceanographic information and a limited amount of ocean optical data are available.

Ocean Wave Simulation Based on Wind Field.

PubMed

Li, Zhongyi; Wang, Hao

2016-01-01

Ocean wave simulation has a wide range of applications in movies, video games and training systems. Wind force is the main energy resource for generating ocean waves, which are the result of the interaction between wind and the ocean surface. While numerous methods to handle simulating oceans and other fluid phenomena have undergone rapid development during the past years in the field of computer graphic, few of them consider to construct ocean surface height field from the perspective of wind force driving ocean waves. We introduce wind force to the construction of the ocean surface height field through applying wind field data and wind-driven wave particles. Continual and realistic ocean waves result from the overlap of wind-driven wave particles, and a strategy was proposed to control these discrete wave particles and simulate an endless ocean surface. The results showed that the new method is capable of obtaining a realistic ocean scene under the influence of wind fields at real time rates.

Bounded relative motion under zonal harmonics perturbations

NASA Astrophysics Data System (ADS)

Baresi, Nicola; Scheeres, Daniel J.

2017-04-01

The problem of finding natural bounded relative trajectories between the different units of a distributed space system is of great interest to the astrodynamics community. This is because most popular initialization methods still fail to establish long-term bounded relative motion when gravitational perturbations are involved. Recent numerical searches based on dynamical systems theory and ergodic maps have demonstrated that bounded relative trajectories not only exist but may extend up to hundreds of kilometers, i.e., well beyond the reach of currently available techniques. To remedy this, we introduce a novel approach that relies on neither linearized equations nor mean-to-osculating orbit element mappings. The proposed algorithm applies to rotationally symmetric bodies and is based on a numerical method for computing quasi-periodic invariant tori via stroboscopic maps, including extra constraints to fix the average of the nodal period and RAAN drift between two consecutive equatorial plane crossings of the quasi-periodic solutions. In this way, bounded relative trajectories of arbitrary size can be found with great accuracy as long as these are allowed by the natural dynamics and the physical constraints of the system (e.g., the surface of the gravitational attractor). This holds under any number of zonal harmonics perturbations and for arbitrary time intervals as demonstrated by numerical simulations about an Earth-like planet and the highly oblate primary of the binary asteroid (66391) 1999 KW4.

Assessment of Export Efficiency Equations in the Southern Ocean Applied to Satellite-Based Net Primary Production

NASA Astrophysics Data System (ADS)

Arteaga, Lionel; Haëntjens, Nils; Boss, Emmanuel; Johnson, Kenneth S.; Sarmiento, Jorge L.

2018-04-01

Carbon export efficiency (e-ratio) is defined as the fraction of organic carbon fixed through net primary production (NPP) that is exported out of the surface productive layer of the ocean. Recent observations for the Southern Ocean suggest a negative e-ratio versus NPP relationship, and a reduced dependency of export efficiency on temperature, different than in the global domain. In this study, we complement information from a passive satellite sensor with novel space-based lidar observations of ocean particulate backscattering to infer NPP over the entire annual cycle, and estimate Southern Ocean export rates from five different empirical models of export efficiency. Inferred Southern Ocean NPP falls within the range of previous studies, with a mean estimate of 15.8 (± 3.9) Pg C yr-1 for the region south of 30°S during the 2005-2016 period. We find that an export efficiency model that accounts for silica(Si)-ballasting, which is constrained by observations with a negative e-ratio versus NPP relationship, shows the best agreement with in situ-based estimates of annual net community production (annual export of 2.7 ± 0.6 Pg C yr-1 south of 30°S). By contrast, models based on the analysis of global observations with a positive e-ratio versus NPP relationship predict annually integrated export rates that are ˜ 33% higher than the Si-dependent model. Our results suggest that accounting for Si-induced ballasting is important for the estimation of carbon export in the Southern Ocean.

Developing an Automated Method for Detection of Operationally Relevant Ocean Fronts and Eddies

NASA Astrophysics Data System (ADS)

Rogers-Cotrone, J. D.; Cadden, D. D. H.; Rivera, P.; Wynn, L. L.

2016-02-01

Since the early 90's, the U.S. Navy has utilized an observation-based process for identification of frontal systems and eddies. These Ocean Feature Assessments (OFA) rely on trained analysts to identify and position ocean features using satellite-observed sea surface temperatures. Meanwhile, as enhancements and expansion of the navy's Hybrid Coastal Ocean Model (HYCOM) and Regional Navy Coastal Ocean Model (RNCOM) domains have proceeded, the Naval Oceanographic Office (NAVO) has provided Tactical Oceanographic Feature Assessments (TOFA) that are based on data-validated model output but also rely on analyst identification of significant features. A recently completed project has migrated OFA production to the ArcGIS-based Acoustic Reach-back Cell Ocean Analysis Suite (ARCOAS), enabling use of additional observational datasets and significantly decreasing production time; however, it has highlighted inconsistencies inherent to this analyst-based identification process. Current efforts are focused on development of an automated method for detecting operationally significant fronts and eddies that integrates model output and observational data on a global scale. Previous attempts to employ techniques from the scientific community have been unable to meet the production tempo at NAVO. Thus, a system that incorporates existing techniques (Marr-Hildreth, Okubo-Weiss, etc.) with internally-developed feature identification methods (from model-derived physical and acoustic properties) is required. Ongoing expansions to the ARCOAS toolset have shown promising early results.

Comparison of ocean mass content change from direct and inversion based approaches

NASA Astrophysics Data System (ADS)

Uebbing, Bernd; Kusche, Jürgen; Rietbroek, Roelof

2017-04-01

The GRACE satellite mission provides an indispensable tool for measuring oceanic mass variations. Such time series are essential to separate global mean sea level rise in thermosteric and mass driven contributions, and thus to constrain ocean heat content and (deep) ocean warming when viewed together with altimetry and Argo data. However, published estimates over the GRACE era differ, not only depending on the time window considered. Here, we will look into sources of such differences with direct and inverse approaches. Deriving ocean mass time series requires several processing steps; choosing a GRACE (and altimetry and Argo) product, data coverage, masks and filters to be applied in either spatial or spectral domain, corrections related to spatial leakage, GIA and geocenter motion need to be accounted for. In this study, we quantify the effects of individual processing choices and assumptions of the direct and inversion based approaches to derive ocean mass content change. Furthermore, we compile the different estimates from existing literature and sources, to highlight the differences.

Strategies for reducing ocean plastic debris should be diverse and guided by science

NASA Astrophysics Data System (ADS)

Rochman, Chelsea M.

2016-04-01

Studies suggest that trillions of microplastic particles are floating on the surface of the global oceans and that the total amount of plastic waste entering the ocean will increase by an order of magnitude by 2025. As such, this ever-increasing problem demands immediate mitigation and reduction. Diverse solutions have been proposed, ranging from source reduction to ocean-based cleanup. These solutions are most effective when guided by scientific evidence. A study published in Environmental Research Letters (Sherman and van Sebille 2016 Environ. Res. Lett. 11 014006) took a closer look at the potential effectiveness of ocean-based cleanup. They conclude that it will be most cost-effective and ecologically beneficial if clean-up efforts focus on the flux of microplastics from the coasts rather than in the center of the oceans where plastic accumulates in so called ‘garbage patches’. If followed, this example may become one of a series of examples where science has informed a solution to the complex problem of plastic pollution.

Vertical Distribution of Bacterial Communities in the Indian Ocean as Revealed by Analyses of 16S rRNA and nasA Genes.

PubMed

Jiang, Xuexia; Jiao, Nianzhi

2016-09-01

Bacteria play an important role in the marine biogeochemical cycles. However, research on the bacterial community structure of the Indian Ocean is scarce, particularly within the vertical dimension. In this study, we investigated the bacterial diversity of the pelagic, mesopelagic and bathypelagic zones of the southwestern Indian Ocean (50.46°E, 37.71°S). The clone libraries constructed by 16S rRNA gene sequence revealed that most phylotypes retrieved from the Indian Ocean were highly divergent from those retrieved from other oceans. Vertical differences were observed based on the analysis of natural bacterial community populations derived from the 16S rRNA gene sequences. Based on the analysis of the nasA gene sequences from GenBank database, a pair of general primers was developed and used to amplify the bacterial nitrate-assimilating populations. Environmental factors play an important role in mediating the bacterial communities in the Indian Ocean revealed by canonical correlation analysis.

Open-Ocean and Coastal Properties of Recent Major Tsunamis

NASA Astrophysics Data System (ADS)

Rabinovich, A.; Thomson, R.; Zaytsev, O.

2017-12-01

The properties of six major tsunamis during the period 2009-2015 (2009 Samoa; 2010 Chile; 2011 Tohoku; 2012 Haida Gwaii; 2014 and 2015 Chile) were thoroughly examined using coastal data from British Columbia, the U.S. West Coast and Mexico, and offshore open-ocean DART and NEPTUNE stations. Based on joint spectral analyses of the tsunamis and background noise, we have developed a method to suppress the influence of local topography and to use coastal observations to determine the underlying spectra of tsunami waves in the deep ocean. The "reconstructed" open-ocean tsunami spectra were found to be in close agreement with the actual tsunami spectra evaluated from the analysis of directly measured open-ocean tsunami records. We have further used the spectral estimates to parameterize tsunamis based on their integral open-ocean spectral characteristics. Three key parameters are introduced to describe individual tsunami events: (1) Integral open-ocean energy; (2) Amplification factor (increase of the mean coastal tsunami variance relative to the open-ocean variance); and (3) Tsunami colour, the frequency composition of the open-ocean tsunami waves. In particular, we found that the strongest tsunamis, associated with large source areas (the 2010 Chile and 2011 Tohoku) are "reddish" (indicating the dominance of low-frequency motions), while small-source events (the 2009 Samoa and 2012 Haida Gwaii) are "bluish" (indicating strong prevalence of high-frequency motions).

Could the acid-base status of Antarctic sea urchins indicate a better-than-expected resilience to near-future ocean acidification?

PubMed

Collard, Marie; De Ridder, Chantal; David, Bruno; Dehairs, Frank; Dubois, Philippe

2015-02-01

Increasing atmospheric carbon dioxide concentration alters the chemistry of the oceans towards more acidic conditions. Polar oceans are particularly affected due to their low temperature, low carbonate content and mixing patterns, for instance upwellings. Calcifying organisms are expected to be highly impacted by the decrease in the oceans' pH and carbonate ions concentration. In particular, sea urchins, members of the phylum Echinodermata, are hypothesized to be at risk due to their high-magnesium calcite skeleton. However, tolerance to ocean acidification in metazoans is first linked to acid-base regulation capacities of the extracellular fluids. No information on this is available to date for Antarctic echinoderms and inference from temperate and tropical studies needs support. In this study, we investigated the acid-base status of 9 species of sea urchins (3 cidaroids, 2 regular euechinoids and 4 irregular echinoids). It appears that Antarctic regular euechinoids seem equipped with similar acid-base regulation systems as tropical and temperate regular euechinoids but could rely on more passive ion transfer systems, minimizing energy requirements. Cidaroids have an acid-base status similar to that of tropical cidaroids. Therefore Antarctic cidaroids will most probably not be affected by decreasing seawater pH, the pH drop linked to ocean acidification being negligible in comparison of the naturally low pH of the coelomic fluid. Irregular echinoids might not suffer from reduced seawater pH if acidosis of the coelomic fluid pH does not occur but more data on their acid-base regulation are needed. Combining these results with the resilience of Antarctic sea urchin larvae strongly suggests that these organisms might not be the expected victims of ocean acidification. However, data on the impact of other global stressors such as temperature and of the combination of the different stressors needs to be acquired to assess the sensitivity of these organisms to global change. © 2014 John Wiley & Sons Ltd.

Seasonal to Decadal-Scale Variability in Satellite Ocean Color and Sea Surface Temperature for the California Current System

NASA Technical Reports Server (NTRS)

Mitchell, B. Greg; Kahru, Mati; Marra, John (Technical Monitor)

2002-01-01

Support for this project was used to develop satellite ocean color and temperature indices (SOCTI) for the California Current System (CCS) using the historic record of CZCS West Coast Time Series (WCTS), OCTS, WiFS and AVHRR SST. The ocean color satellite data have been evaluated in relation to CalCOFI data sets for chlorophyll (CZCS) and ocean spectral reflectance and chlorophyll OCTS and SeaWiFS. New algorithms for the three missions have been implemented based on in-water algorithm data sets, or in the case of CZCS, by comparing retrieved pigments with ship-based observations. New algorithms for absorption coefficients, diffuse attenuation coefficients and primary production have also been evaluated. Satellite retrievals are being evaluated based on our large data set of pigments and optics from CalCOFI.

SSL: Signal Similarity-Based Localization for Ocean Sensor Networks.

PubMed

Chen, Pengpeng; Ma, Honglu; Gao, Shouwan; Huang, Yan

2015-11-24

Nowadays, wireless sensor networks are often deployed on the sea surface for ocean scientific monitoring. One of the important challenges is to localize the nodes' positions. Existing localization schemes can be roughly divided into two types: range-based and range-free. The range-based localization approaches heavily depend on extra hardware capabilities, while range-free ones often suffer from poor accuracy and low scalability, far from the practical ocean monitoring applications. In response to the above limitations, this paper proposes a novel signal similarity-based localization (SSL) technology, which localizes the nodes' positions by fully utilizing the similarity of received signal strength and the open-air characteristics of the sea surface. In the localization process, we first estimate the relative distance between neighboring nodes through comparing the similarity of received signal strength and then calculate the relative distance for non-neighboring nodes with the shortest path algorithm. After that, the nodes' relative relation map of the whole network can be obtained. Given at least three anchors, the physical locations of nodes can be finally determined based on the multi-dimensional scaling (MDS) technology. The design is evaluated by two types of ocean experiments: a zonal network and a non-regular network using 28 nodes. Results show that the proposed design improves the localization accuracy compared to typical connectivity-based approaches and also confirm its effectiveness for large-scale ocean sensor networks.

Oceanic Lithosphere/Asthenosphere Boundary from surface wave dispersion data

NASA Astrophysics Data System (ADS)

Burgos, G.; Montagner, J.; Beucler, E.; Capdeville, Y.; Mocquet, A.

2013-12-01

The nature of Lithosphere-Asthenosphere boundary (LAB) is controversial according to different types of observations. Using a massive dataset of surface wave dispersions in a broad frequency range (15-300s), we have developed a 3-D tomographic model (1st order perturbation theory) of the upper-mantle at the global scale. It is used to derive maps of LAB from the resolved elastic parameters. The key effects of shallow layers and anisotropy are taken into account in the inversion process. We investigate LAB distributions primarily below oceans according to three different proxies which corresponds to the base of the lithosphere from the vertically polarized shear velocity variation at depth, the top of the radial anisotropy positive anomaly and from the changes in orientation of the fast axis of azimuthal anisotropy. The LAB depth determinations of the different proxies are basically consistent for each oceanic region. The estimations of the LAB depth based on the shear velocity proxy increase from thin (20 km) lithosphere in the ridges to thick (120--130 km) old ocean lithosphere. The radial anisotropy proxy presents a very fast increase of the LAB depth from the ridges, from 50 km to older ocean where it reaches a remarkable monotonic sub-horizontal profile (70--80 km). LAB depths inferred from azimuthal anisotropy proxy show deeper values for the increasing oceanic lithosphere (130--135 km). The results present two types of pattern of the age of oceanic lithosphere evolution with the LAB depth. The shear velocity and azimuthal anisotropy proxies show age-dependent profiles in agreement with thermal plate models while the LAB based on radial anisotropy is characterized by a shallower depth, defining a sub-horizontal interface with a very small age dependence for all three main oceans (Pacific, Atlantic and Indian). These different patterns raise questions about the nature of the LAB in the oceanic regions, and of the formation of oceanic plates.

Toward a multivariate reanalysis of the North Atlantic ocean biogeochemistry during 1998-2006 based on the assimilation of SeaWiFS chlorophyll data

NASA Astrophysics Data System (ADS)

Fontana, C.; Brasseur, P.; Brankart, J.-M.

2012-04-01

Today, the routine assimilation of satellite data into operational models of the ocean circulation is mature enough to enable the production of global reanalyses describing the ocean circulation variability during the past decades. The expansion of the "reanalysis" concept from ocean physics to biogeochemistry is a timely challenge that motivates the present study. The objective of this paper is to investigate the potential benefits of assimilating satellite-estimated chlorophyll data into a basin-scale three-dimensional coupled physical-biogeochemical model of the North-Atlantic. The aim is on one hand to improve forecasts of ocean biogeochemical properties and on the other hand to define a methodology for producing data-driven climatologies based on coupled physical-biogeochemical modelling. A simplified variant of the Kalman filter is used to assimilate ocean color data during a 9 year-long period. In this frame, two experiences are carried out, with and without anamorphic transformations of the state vector variables. Data assimilation efficiency is assessed with respect to the assimilated data set, the nitrate World Ocean Atlas database and a derived climatology. Along the simulation period, the non-linear assimilation scheme clearly improves the surface chlorophyll concentrations analysis and forecast, especially in the North Atlantic bloom region. Nitrate concentration forecasts are also improved thanks to the assimilation of ocean color data while this improvement is limited to the upper layer of the water column, in agreement with recent related litterature. This feature is explained by the weak correlation taken into account by the assimilation between surface phytoplankton and nitrate concentration deeper than 50 m. The assessement of the non-linear assimilation experiments indicates that the proposed methodology provides the skeleton of an assimilative system suitable for reanalysing the ocean biogeochemistry based on ocean color data.

Toward a multivariate reanalysis of the North Atlantic Ocean biogeochemistry during 1998-2006 based on the assimilation of SeaWiFS chlorophyll data

NASA Astrophysics Data System (ADS)

Fontana, C.; Brasseur, P.; Brankart, J.-M.

2013-01-01

Today, the routine assimilation of satellite data into operational models of ocean circulation is mature enough to enable the production of global reanalyses describing the ocean circulation variability during the past decades. The expansion of the "reanalysis" concept from ocean physics to biogeochemistry is a timely challenge that motivates the present study. The objective of this paper is to investigate the potential benefits of assimilating satellite-estimated chlorophyll data into a basin-scale three-dimensional coupled physical-biogeochemical model of the North Atlantic. The aim is on the one hand to improve forecasts of ocean biogeochemical properties and on the other hand to define a methodology for producing data-driven climatologies based on coupled physical-biogeochemical modeling. A simplified variant of the Kalman filter is used to assimilate ocean color data during a 9-year period. In this frame, two experiments are carried out, with and without anamorphic transformations of the state vector variables. Data assimilation efficiency is assessed with respect to the assimilated data set, nitrate of the World Ocean Atlas database and a derived climatology. Along the simulation period, the non-linear assimilation scheme clearly improves the surface analysis and forecast chlorophyll concentrations, especially in the North Atlantic bloom region. Nitrate concentration forecasts are also improved thanks to the assimilation of ocean color data while this improvement is limited to the upper layer of the water column, in agreement with recent related literature. This feature is explained by the weak correlation taken into account by the assimilation between surface phytoplankton and nitrate concentrations deeper than 50 meters. The assessment of the non-linear assimilation experiments indicates that the proposed methodology provides the skeleton of an assimilative system suitable for reanalyzing the ocean biogeochemistry based on ocean color data.

Ocean FEST (Families Exploring Science Together)

NASA Astrophysics Data System (ADS)

Bruno, B. C.; Wiener, C. S.

2009-12-01

Ocean FEST (Families Exploring Science Together) exposes families to cutting-edge ocean science research and technology in a fun, engaging way. Research has shown that family involvement in science education adds significant value to the experience. Our overarching goal is to attract underrepresented students (including Native Hawaiians, Pacific Islanders and girls) to geoscience careers. A second goal is to communicate to diverse audiences that geoscience is directly relevant and applicable to their lives, and critical in solving challenges related to global climate change. Ocean FEST engages elementary school students, parents, teachers, and administrators in family science nights based on a proven model developed by Art and Rene Kimura of the Hawaii Space Grant Consortium. Our content focuses on the role of the oceans in climate change, and is based on the transformative research of the NSF Center for Microbial Oceanography: Research and Education (C-MORE) and the Hawaii Institute of Marine Biology (HIMB). Through Ocean FEST, underrepresented students and their parents and teachers learn about new knowledge being generated at Hawaii’s world-renowned ocean research institutes. In the process, they learn about fundamental geoscience concepts and career opportunities. This project is aligned with C-MORE’s goal of increasing the number of underrepresented students pursuing careers in the ocean and earth sciences, and related disciplines. Following a successful round of pilot events at elementary schools on Oahu, funding was obtained through NSF Opportunities for Enhancing Diversity in the Geosciences to implement a three-year program at minority-serving elementary schools in Hawaii. Deliverables include 20 Ocean FEST events per year (each preceded by teacher professional development training), a standards-based program that will be disseminated locally and nationally, three workshops to train educators in program delivery, and an Ocean FEST science kit. In addition, we are currently conducting a series of pilot events at the middle school level at underserved schools at neighbor islands, funded through the Hawaii Innovation Initiative (Act 111). Themes addressed include community outreach, capacity building, teacher preparation, and use of technology.

40 CFR 227.20 - Basis for determination.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 227.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Impact of the Proposed... subpart E will be based on the impact of the proposed dumping on specific uses of the ocean rather than on...

System Design for Ocean Sensor Data Transmission Based on Inductive Coupling

NASA Astrophysics Data System (ADS)

Xu, Ming; Liu, Fei; Zong, Yuan; Hong, Feng

Ocean observation is the precondition to explore and utilize ocean. How to acquire ocean data in a precise, efficient and real-time way is the key question of ocean surveillance. Traditionally, there are three types of methods for ocean data transmission: underwater acoustic, GPRS via mobile network and satellite communication. However, none of them can meet the requirements of efficiency, accuracy, real-time and low cost at the same time. In this paper, we propose a new wireless transmission system for underwater sensors, which established on FGR wireless modules, combined with inductive coupling lab and offshore experiments confirmed the feasibility and effectiveness of the proposed wireless transmission system.

Suomi NPP VIIRS Ocean Color Data Product Early Mission Assessment

NASA Technical Reports Server (NTRS)

Turpie, Kevin R.; Robinson, Wayne D.; Franz, Bryan A.; Eplee, Robert E., Jr.; Meister, Gerhard; Fireman, Gwyn F.; Patt, Frederick S.; Barnes, Robert A.; McClain, Charles R.

2013-01-01

Following the launch of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polarorbiting Partnership (NPP) spacecraft, the NASA NPP VIIRS Ocean Science Team (VOST) began an evaluation of ocean color data products to determine whether they could continue the existing NASA ocean color climate data record (CDR). The VOST developed an independent evaluation product based on NASA algorithms with a reprocessing capability. Here we present a preliminary assessment of both the operational ocean color data products and the NASA evaluation data products regarding their applicability to NASA science objectives.

Upper-Ocean Thermal Structure and the Western North Pacific Category 5 Typhoons. Part 1. Ocean Features and the Category 5 Typhoons’ Intensification

DTIC Science & Technology

2008-09-01

Structure and the Western North Pacific Category 5 Typhoons. Part 1: Ocean Features and the Category 5 Typhoons’ Intensification 5a. CONTRACT NUMBER...intensification of category 5 cyclones. Based on 13 yr of satellite altimetry data, in situ &climatological upper-ocean thermal structure data, best-track...Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 3288 MONTHLY WEATHER REVIEW VOLUME 136 Upper-Ocean Thermal Structure and the Western North

Marine geodesy a multipurpose approach to solve oceanic problems. [including submersible navigation under iced seas, demarcation and determination of boundaries in deep ocean, tsunamis, and ecology

NASA Technical Reports Server (NTRS)

Saxena, N.

1974-01-01

Various current and future problem areas of marine geodesy are identified. These oceanic problem areas are highly diversified and include submersible navigation under ice seas, demarcation and determination of boundaries in deep ocean, tsunamis, ecology, etc., etc. Their achieved as well as desired positional accuracy estimates, based upon publications and discussions, are also given. A multipurpose approach to solve these problems is described. An optimum configuration of an ocean-bottom control-net unit is provided.

Ocean FEST: Families Exploring Science Together

ERIC Educational Resources Information Center

Bruno, Barbara C.; Wiener, Carlie; Kimura, Arthur; Kimura, Rene

2011-01-01

This project engages elementary school students, parents, teachers, and administrators in ocean-themed family science nights based on a proven model. Our key goals are to: (1) educate participants about ocean and earth science issues that are relevant to their communities; and (2) inspire more underrepresented students, including Native Hawaiians,…

Undergraduate Research Experience in Ocean/Marine Science (URE-OMS) with African Student Component

DTIC Science & Technology

2011-01-01

The Undergraduate Research Experience in Ocean/Marine Science program supports active participation by underrepresented undergraduate students in remote sensing and Ocean/Marine Science research training activities. The program is based on a model for undergraduate research programs supported by the National Science Foundation . The

Upper-Ocean Processes under the Stratus Cloud Deck in the Southeast Pacific Ocean

DTIC Science & Technology

2010-01-01

resolving Hybrid Coordinate Ocean Model (HYCOM). Both are compared with estimates based on Woods Hole Oceano - graphic Institution (WHOI) Improved...Jason-1 and Jason-2 sea surface heights and geostrophic currents (computed from absolute topography) produced by Segment Sol Multimissions d’Altimétrie

40 CFR 227.20 - Basis for determination.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 227.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Impact of the Proposed... subpart E will be based on the impact of the proposed dumping on specific uses of the ocean rather than on...

40 CFR 227.20 - Basis for determination.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 227.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Impact of the Proposed... subpart E will be based on the impact of the proposed dumping on specific uses of the ocean rather than on...

40 CFR 227.20 - Basis for determination.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Section 227.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Impact of the Proposed... subpart E will be based on the impact of the proposed dumping on specific uses of the ocean rather than on...

40 CFR 227.20 - Basis for determination.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 227.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Impact of the Proposed... subpart E will be based on the impact of the proposed dumping on specific uses of the ocean rather than on...

The reinvigoration of the Southern Ocean carbon sink.

PubMed

Landschützer, Peter; Gruber, Nicolas; Haumann, F Alexander; Rödenbeck, Christian; Bakker, Dorothee C E; van Heuven, Steven; Hoppema, Mario; Metzl, Nicolas; Sweeney, Colm; Takahashi, Taro; Tilbrook, Bronte; Wanninkhof, Rik

2015-09-11

Several studies have suggested that the carbon sink in the Southern Ocean-the ocean's strongest region for the uptake of anthropogenic CO2 -has weakened in recent decades. We demonstrated, on the basis of multidecadal analyses of surface ocean CO2 observations, that this weakening trend stopped around 2002, and by 2012, the Southern Ocean had regained its expected strength based on the growth of atmospheric CO2. All three Southern Ocean sectors have contributed to this reinvigoration of the carbon sink, yet differences in the processes between sectors exist, related to a tendency toward a zonally more asymmetric atmospheric circulation. The large decadal variations in the Southern Ocean carbon sink suggest a rather dynamic ocean carbon cycle that varies more in time than previously recognized. Copyright © 2015, American Association for the Advancement of Science.

Wave–turbulence interaction-induced vertical mixing and its effects in ocean and climate models

PubMed Central

Qiao, Fangli; Yuan, Yeli; Deng, Jia; Dai, Dejun; Song, Zhenya

2016-01-01

Heated from above, the oceans are stably stratified. Therefore, the performance of general ocean circulation models and climate studies through coupled atmosphere–ocean models depends critically on vertical mixing of energy and momentum in the water column. Many of the traditional general circulation models are based on total kinetic energy (TKE), in which the roles of waves are averaged out. Although theoretical calculations suggest that waves could greatly enhance coexisting turbulence, no field measurements on turbulence have ever validated this mechanism directly. To address this problem, a specially designed field experiment has been conducted. The experimental results indicate that the wave–turbulence interaction-induced enhancement of the background turbulence is indeed the predominant mechanism for turbulence generation and enhancement. Based on this understanding, we propose a new parametrization for vertical mixing as an additive part to the traditional TKE approach. This new result reconfirmed the past theoretical model that had been tested and validated in numerical model experiments and field observations. It firmly establishes the critical role of wave–turbulence interaction effects in both general ocean circulation models and atmosphere–ocean coupled models, which could greatly improve the understanding of the sea surface temperature and water column properties distributions, and hence model-based climate forecasting capability. PMID:26953182

Upper Atmosphere Heating From Ocean-Generated Acoustic Wave Energy

DOE PAGES

Bowman, D. C.; Lees, J. M.

2018-04-27

We present that colliding sea surface waves generate the ocean microbarom, an acoustic signal that may transmit significant energy to the upper atmosphere. Previous estimates of acoustic energy flux from the ocean microbarom and mountain-wind interactions are on the order of 0.01 to 1 mW/m 2, heating the thermosphere by tens of Kelvins per day. We captured upgoing ocean microbarom waves with a balloon-borne infrasound microphone; the maximum acoustic energy flux was approximately 0.05 mW/m 2. This is about half the average value reported in previous ground-based microbarom observations spanning 8 years. The acoustic flux from the microbarom episode describedmore » here may have heated the thermosphere by several Kelvins per day while the source persisted. Lastly, we suggest that ocean wave models could be used to parameterize acoustically generated heating of the upper atmosphere based on sea state.« less

Upper Atmosphere Heating From Ocean-Generated Acoustic Wave Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowman, D. C.; Lees, J. M.

We present that colliding sea surface waves generate the ocean microbarom, an acoustic signal that may transmit significant energy to the upper atmosphere. Previous estimates of acoustic energy flux from the ocean microbarom and mountain-wind interactions are on the order of 0.01 to 1 mW/m 2, heating the thermosphere by tens of Kelvins per day. We captured upgoing ocean microbarom waves with a balloon-borne infrasound microphone; the maximum acoustic energy flux was approximately 0.05 mW/m 2. This is about half the average value reported in previous ground-based microbarom observations spanning 8 years. The acoustic flux from the microbarom episode describedmore » here may have heated the thermosphere by several Kelvins per day while the source persisted. Lastly, we suggest that ocean wave models could be used to parameterize acoustically generated heating of the upper atmosphere based on sea state.« less

Advances in Understanding Decadal Climate Variability

NASA Technical Reports Server (NTRS)

Busalaacchi, Antonio J.

1998-01-01

Recently, a joint Brazil-France-U.S. program, known as PIRATA (Pilot Research moored Array in the Tropical Atlantic), was proposed to begin the deployment of moored measurement platforms in the tropical Atlantic in order to enhance the existing observational data base and subsequent understanding of the processes by which the ocean and atmosphere couple in key regions of the tropical Atlantic Ocean. Empirical studies have suggested that there are strong relationships between tropical Atlantic upper ocean variability, SST, ocean-atmosphere coupling and regional climate variability. During the early 1980's a coordinated set of surface wind, subsurface thermal structure, and subsurface current observations were obtained as part of the U.S.-France SEQUAL- FOCAL process experiment designed to observe the seasonal response of the tropical Atlantic Ocean to surface forcing. Since that time, however, the observational data base for the tropical Atlantic Ocean has disintegrated to a few shiptracks measuring ocean temperatures and a small collection of tide gauge stations measuring sea level. A more comprehensive set of observations, modeling and empirical studies is now in order to make progress on understanding the regional climate variability. The proposed PIRATA program will use mooring platforms similar to the tropical Pacific Ocean TAO array to measure surface fluxes of momentum and heat and the corresponding changes in the upper ocean thermal structure. It is anticipated that the oceanic data from this monitoring array will also be used in a predictive mode for initialization studies of regional coupled climate models. Of particular interest are zonal and meridional modes of ocean-atmosphere variability within the tropical Atlantic basin that have significant impacts on the regional climate of the bordering continents.

Advances in Understanding Decadal Climate Variability

NASA Technical Reports Server (NTRS)

Busalacchi, Antonio J.

1999-01-01

Recently, a joint Brazil-France-U.S. program, known as PIRATA (Pilot Research moored Array in the Tropical Atlantic), was proposed to begin the deployment of moored measurement platforms in the tropical Atlantic in order to enhance the existing observational data base and subsequent understanding of the processes by which the ocean and atmosphere couple in key regions of the tropical Atlantic Ocean. Empirical studies have suggested that there are strong relationships between tropical Atlantic upper ocean variability, SST, ocean-atmosphere coupling and regional climate variability. During the early 1980's a coordinated set of surface wind, subsurface thermal structure, and subsurface current observations were obtained as part of the U.S.-France SEQUAL-FOCAL process experiment designed to observe the seasonal response of the tropical Atlantic Ocean to surface forcing. Since that time, however, the observational data base for the tropical Atlantic Ocean has disintegrated to a few ship-tracks measuring ocean temperatures and a small collection of tide gauge stations measuring sea level. A more comprehensive set of observations, modeling and empirical studies is now in order to make progress on understanding the regional climate variability. The proposed PIRATA program will use mooring platforms similar to the tropical Pacific Ocean TAO array to measure surface fluxes of momentum and heat and the corresponding changes in the upper ocean thermal structure. It is anticipated that the oceanic data from this monitoring array will also be used in a predictive mode for initialization studies of regional coupled climate models. Of particular interest are zonal and meridional modes of ocean-atmosphere variability within the tropical Atlantic basin that have significant impacts on the regional climate of the bordering continents.

Ocean surface partitioning strategies using ocean colour remote Sensing: A review

NASA Astrophysics Data System (ADS)

Krug, Lilian Anne; Platt, Trevor; Sathyendranath, Shubha; Barbosa, Ana B.

2017-06-01

The ocean surface is organized into regions with distinct properties reflecting the complexity of interactions between environmental forcing and biological responses. The delineation of these functional units, each with unique, homogeneous properties and underlying ecosystem structure and dynamics, can be defined as ocean surface partitioning. The main purposes and applications of ocean partitioning include the evaluation of particular marine environments; generation of more accurate satellite ocean colour products; assimilation of data into biogeochemical and climate models; and establishment of ecosystem-based management practices. This paper reviews the diverse approaches implemented for ocean surface partition into functional units, using ocean colour remote sensing (OCRS) data, including their purposes, criteria, methods and scales. OCRS offers a synoptic, high spatial-temporal resolution, multi-decadal coverage of bio-optical properties, relevant to the applications and value of ocean surface partitioning. In combination with other biotic and/or abiotic data, OCRS-derived data (e.g., chlorophyll-a, optical properties) provide a broad and varied source of information that can be analysed using different delineation methods derived from subjective, expert-based to unsupervised learning approaches (e.g., cluster, fuzzy and empirical orthogonal function analyses). Partition schemes are applied at global to mesoscale spatial coverage, with static (time-invariant) or dynamic (time-varying) representations. A case study, the highly heterogeneous area off SW Iberian Peninsula (NE Atlantic), illustrates how the selection of spatial coverage and temporal representation affects the discrimination of distinct environmental drivers of phytoplankton variability. Advances in operational oceanography and in the subject area of satellite ocean colour, including development of new sensors, algorithms and products, are among the potential benefits from extended use, scope and applications of ocean surface partitioning using OCRS.

Arrival Time Tracking of Partially Resolved Acoustic Rays with Application to Ocean Acoustic Tomography

DTIC Science & Technology

1991-03-01

ocean acoustic tomography. A straightforward method of arrival time estimation, based on locating the maximum value of an interpolated arrival, was...used with limited success for analysis of data from the December 1988 Monterey Bay Tomography Experiment. Close examination of the data revealed multiple...estimation of arrival times along an ocean acoustic ray path is an important component of ocean acoustic tomography. A straightforward method of arrival time

Santa Margarita Lagoon Water Quality Monitoring Data

DTIC Science & Technology

2012-08-01

sits entirely within the boundaries of Marine Corps Base Camp Pendleton. It forms up where the Santa Margarita River meets the Pacific Ocean just north...of Oceanside, California. The western boundary of the lagoon is the beach berm that borders the ocean . The estuarine lagoon is usually open to the... ocean through a limited section of berm, although there are occasions when the lagoon is effectively closed to exchange with the ocean . The eastern

CEOS Ocean Variables Enabling Research and Applications for Geo (COVERAGE)

NASA Astrophysics Data System (ADS)

Tsontos, V. M.; Vazquez, J.; Zlotnicki, V.

2017-12-01

The CEOS Ocean Variables Enabling Research and Applications for GEO (COVERAGE) initiative seeks to facilitate joint utilization of different satellite data streams on ocean physics, better integrated with biological and in situ observations, including near real-time data streams in support of oceanographic and decision support applications for societal benefit. COVERAGE aligns with programmatic objectives of CEOS (the Committee on Earth Observation Satellites) and the missions of GEO-MBON (Marine Biodiversity Observation Network) and GEO-Blue Planet, which are to advance and exploit synergies among the many observational programs devoted to ocean and coastal waters. COVERAGE is conceived of as 3 year pilot project involving international collaboration. It focuses on implementing technologies, including cloud based solutions, to provide a data rich, web-based platform for integrated ocean data delivery and access: multi-parameter observations, easily discoverable and usable, organized by disciplines, available in near real-time, collocated to a common grid and including climatologies. These will be complemented by a set of value-added data services available via the COVERAGE portal including an advanced Web-based visualization interface, subsetting/extraction, data collocation/matchup and other relevant on demand processing capabilities. COVERAGE development will be organized around priority use cases and applications identified by GEO and agency partners. The initial phase will be to develop co-located 25km products from the four Ocean Virtual Constellations (VCs), Sea Surface Temperature, Sea Level, Ocean Color, and Sea Surface Winds. This aims to stimulate work among the ocean VCs while developing products and system functionality based on community recommendations. Such products as anomalies from a time mean, would build on the theme of applications with a relevance to CEOS/GEO mission and vision. Here we provide an overview of the COVERAGE initiative with an emphasis on international collaborative aspects entailed with the intent of soliciting community feedback as we develop and implement

Ocean Sense: Student-Led, Real-Time Research at the Bottom of the Ocean - Without Leaving the Classroom

NASA Astrophysics Data System (ADS)

Pelz, M.; Hoeberechts, M.; McLean, M. A.; Riddell, D. J.; Ewing, N.; Brown, J. C.

2016-12-01

This presentation outlines the authentic research experiences created by Ocean Networks Canada's Ocean Sense program, a transformative education program that connects students and teachers with place-based, real-time data via the Internet. This program, developed in collaboration with community educators, features student-centric activities, clearly outlined learning outcomes, assessment tools and curriculum aligned content. Ocean Networks Canada (ONC), an initiative of the University of Victoria, develops, operates, and maintains cabled ocean observatory systems. Technologies developed on the world-leading NEPTUNE and VENUS observatories have been adapted for small coastal installations called "community observatories," which enable community members to directly monitor conditions in the local ocean environment. Data from these observatories are fundamental to lessons and activities in the Ocean Sense program. Marketed as Ocean Sense: Local observations, global connections, the program introduces middle and high school students to research methods in biology, oceanography and ocean engineering. It includes a variety of resources and opportunities to excite students and spark curiosity about the ocean environment. The program encourages students to connect their local observations to global ocean processes and the observations of students in other geographic regions. Connection to place and local relevance of the program is enhanced through an emphasis on Indigenous and place-based knowledge. The program promotes of cross-cultural learning with the inclusion of Indigenous knowledge of the ocean. Ocean Sense provides students with an authentic research experience by connecting them to real-time data, often within their own communities. Using the freely accessible data portal, students can curate the data they need from a range of instruments and time periods. Further, students are not restricted to their local community; if their question requires a greater range of data, they also have access to the other observatories in the network. Our presentation will explore the design, implementation and lessons learned from the ongoing development of the Ocean Sense program, from its inception to its current form today. Sample activities will be made available.

Long-Term Evaluation of Ocean Tidal Variation Models of Polar Motion and UT1

NASA Astrophysics Data System (ADS)

Karbon, Maria; Balidakis, Kyriakos; Belda, Santiago; Nilsson, Tobias; Hagedoorn, Jan; Schuh, Harald

2018-04-01

Recent improvements in the development of VLBI (very long baseline interferometry) and other space geodetic techniques such as the global navigation satellite systems (GNSS) require very precise a-priori information of short-period (daily and sub-daily) Earth rotation variations. One significant contribution to Earth rotation is caused by the diurnal and semi-diurnal ocean tides. Within this work, we developed a new model for the short-period ocean tidal variations in Earth rotation, where the ocean tidal angular momentum model and the Earth rotation variation have been setup jointly. Besides the model of the short-period variation of the Earth's rotation parameters (ERP), based on the empirical ocean tide model EOT11a, we developed also ERP models, that are based on the hydrodynamic ocean tide models FES2012 and HAMTIDE. Furthermore, we have assessed the effect of uncertainties in the elastic Earth model on the resulting ERP models. Our proposed alternative ERP model to the IERS 2010 conventional model considers the elastic model PREM and 260 partial tides. The choice of the ocean tide model and the determination of the tidal velocities have been identified as the main uncertainties. However, in the VLBI analysis all models perform on the same level of accuracy. From these findings, we conclude that the models presented here, which are based on a re-examined theoretical description and long-term satellite altimetry observation only, are an alternative for the IERS conventional model but do not improve the geodetic results.

100% of the World Ocean Floor Mapped by 2030 - Contribution of the South and West Pacific Regional Data Assembly and Coordination Centre to the Seabed 2030 Initiative

NASA Astrophysics Data System (ADS)

Lamarche, G.; Neil, H.; Stagpoole, V. M.; Greenland, A.; Mackay, K.; Black, J.; Griffin, E.

2017-12-01

The Seabed 2030 SaWPac Centre (South and West Pacific Ocean Regional Data Assembly and Coordination Centre) has been formed to generate new high resolution ocean floor maps of the western and southern Pacific Ocean. The centre is part of the joint Nippon Foundation and the General Bathymetric Chart of the Oceans (GEBCO) initiative to produce a definitive map of the World Ocean floor by 2030, empowering the world to make policy decisions, use the ocean sustainability and undertake scientific research based on detailed bathymetric information of the Earth's seabed. The SaWPac Centre is based at NIWA Wellington (New Zealand) and includes a collaborative partnership with GNS Science and Land Information New Zealand. It is responsible for the region from South America to Australia, north of latitude 50°S to 10° north of the Equator and the western part of the Northern Pacific Ocean to Russia. The region includes the world's deepest trenches and also covers some of the remotest oceans where bathymetric data form existing ship tracks is spaced up to 100 km apart. The challenge for the SaWPac Centre is to collate and combine all the available bathymetric data from the numerous nations that have surveyed in the region. The centre will also promote efforts to collect new data and contribute to map products generated by the Seabed 2030 global mapping project.

Report of the EOS oceans panel to the payload panel

NASA Astrophysics Data System (ADS)

Abbott, Mark R.; Freilich, Michael H.

1992-11-01

The atmosphere and the ocean are the two great fluids of the earth system. Changes in the coupling of these two fluids will have a profound impact on the Earth's climate and biogeochemical systems. Although changes in atmospheric composition and dynamics are the usual focus of global climate models, it is apparent that the ocean plays a critical role in modulating the magnitude and rate of these changes. The ocean is responsible for nearly half of the poleward heat flux as well as for a significant portion of the uptake of atmospheric carbon dioxide. However, the processes governing the flux of materials and energy between the ocean atmosphere are poorly understood. Such processes include not only physical and chemical dynamics, but also biological processes which act to modify the chemical composition of the ocean as well as the trapping of solar energy as heat in the upper water column. Thus it is essential that the ocean be studied as a complete system of physical, chemical, and biological processes. Overlapping measurements must be made for at least 10-15 years to resolve critical low frequency fluctuations. The present EOS plan relies heavily on non-EOS entities to provide critical data sets for ocean studies. Although such partnerships are usually beneficial, there are risks that must be considered in terms of data coverage, quality, resolution, and availability. A simple replacement of an EOS sensor with a non-EOS sensor based on the fact that they both measure the same quantities will not guarantee that critical measurements will be made to address IPCC priorities in the area of ocean processes. EOS must continue to pursue appropriate methods to ensure that such partner — provided measurements meet scientific requirements. Such methods are analogous to contigencies applied in the area of schedules, cost, and performance for instrument projects. EOS must foster strong ties between US scientists and their foreign counterparts, in order to develop partnerships based on science, rather than just based on financial or administrative considerations. Effective international programs are necessary for a truly globally-based study, and they must begin with working scientists. In the area of ocean sciences, several opportunities exist in the early EOS era, such as ERS-1, TOPEX/Poseidon, and NSCAT / OCTS / SeaWiFS. We strongly encourage EOS to contribute to these efforts.

Excitation of the Earth's Chandler wobble by a turbulent oceanic double-gyre

NASA Astrophysics Data System (ADS)

Naghibi, S. E.; Jalali, M. A.; Karabasov, S. A.; Alam, M.-R.

2017-04-01

We develop a layer-averaged, multiple-scale spectral ocean model and show how an oceanic double-gyre can communicate with the Earth's Chandler wobble. The overall transfers of energy and angular momentum from the double-gyre to the Chandler wobble are used to calibrate the turbulence parameters of the layer-averaged model. Our model is tested against a multilayer quasi-geostrophic ocean model in turbulent regime, and base states used in parameter identification are obtained from mesoscale eddy resolving numerical simulations. The Chandler wobble excitation function obtained from the model predicts a small role of North Atlantic ocean region on the wobble dynamics as compared to all oceans, in agreement with the existing observations.

High-latitude ocean ventilation and its role in Earth's climate transitions

PubMed Central

MacGilchrist, Graeme A. ; Brown, Peter J.; Evans, D. Gwyn; Meijers, Andrew J. S.; Zika, Jan D.

2017-01-01

The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’. PMID:28784714

Proceedings of oceans 87. The ocean - an international workplace

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-01-01

This book includes proceedings containing 347 papers. Some of the topics are: ICE -Cold ocean and ice research; ICE-1-Icebergs; ICE-2-Sea ice and structures; IE-3-Cold ocean instrumentation; ICE-4-Ocean and ice; INS-Oceanographic instrumentation; INS-1-Acoustic Doppler Current profilers; ENG-1-New solutions to old problems; ENG-2-energy from the ocean; ENG-3-Cables and connectors; POL-Policy, education and technology transfer; POL-1-International issues; POL-2-Ocean space utilization; POL-3-Economics, planning and management; SCI-6-fish stock assessment; ACI-7-Coastal currents and sediment; SCI-9-Satellite navigation; SCI-10-Deep sea minerals and methods of recovery; ODS-Fifth working symposium on oceanographic data system; ODS-1-Data base management; UND-Underwater work systems; UND-1-Diving for science.

High-latitude ocean ventilation and its role in Earth's climate transitions.

PubMed

Naveira Garabato, Alberto C; MacGilchrist, Graeme A; Brown, Peter J; Evans, D Gwyn; Meijers, Andrew J S; Zika, Jan D

2017-09-13

The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Authors.

Reversed flow of Atlantic deep water during the Last Glacial Maximum.

PubMed

Negre, César; Zahn, Rainer; Thomas, Alexander L; Masqué, Pere; Henderson, Gideon M; Martínez-Méndez, Gema; Hall, Ian R; Mas, José L

2010-11-04

The meridional overturning circulation (MOC) of the Atlantic Ocean is considered to be one of the most important components of the climate system. This is because its warm surface currents, such as the Gulf Stream, redistribute huge amounts of energy from tropical to high latitudes and influence regional weather and climate patterns, whereas its lower limb ventilates the deep ocean and affects the storage of carbon in the abyss, away from the atmosphere. Despite its significance for future climate, the operation of the MOC under contrasting climates of the past remains controversial. Nutrient-based proxies and recent model simulations indicate that during the Last Glacial Maximum the convective activity in the North Atlantic Ocean was much weaker than at present. In contrast, rate-sensitive radiogenic (231)Pa/(230)Th isotope ratios from the North Atlantic have been interpreted to indicate only minor changes in MOC strength. Here we show that the basin-scale abyssal circulation of the Atlantic Ocean was probably reversed during the Last Glacial Maximum and was dominated by northward water flow from the Southern Ocean. These conclusions are based on new high-resolution data from the South Atlantic Ocean that establish the basin-scale north to south gradient in (231)Pa/(230)Th, and thus the direction of the deep ocean circulation. Our findings are consistent with nutrient-based proxies and argue that further analysis of (231)Pa/(230)Th outside the North Atlantic basin will enhance our understanding of past ocean circulation, provided that spatial gradients are carefully considered. This broader perspective suggests that the modern pattern of the Atlantic MOC-with a prominent southerly flow of deep waters originating in the North Atlantic-arose only during the Holocene epoch.

76 FR 4139 - National Ocean Council; Development of Strategic Action Plans for the National Policy for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-24

... OFFICE OF SCIENCE AND TECHNOLOGY POLICY National Ocean Council; Development of Strategic Action Plans for the National Policy for the Stewardship of the Ocean, Our Coasts, and the Great Lakes ACTION... the Great Lakes. The National Policy provides a comprehensive approach, based on science and...

Comparison of ocean surface solar irradiance in the GLA General Circulation Model and satellite-based calculations

NASA Technical Reports Server (NTRS)

Chertock, Beth; Sud, Y. C.

1993-01-01

A global, 7-year satellite-based record of ocean surface solar irradiance (SSI) is used to assess the realism of ocean SSI simulated by the nine-layer Goddard Laboratory for Atmospheres (GLA) General Circulation Model (GCM). January and July climatologies of net SSI produced by the model are compared with corresponding satellite climatologies for the world oceans between 54 deg N and 54 deg S. This comparison of climatologies indicates areas of strengths and weaknesses in the GCM treatment of cloud-radiation interactions, the major source of model uncertainty. Realism of ocean SSI is also important for applications such as incorporating the GLA GCM into a coupled ocean-atmosphere GCM. The results show that the GLA GCM simulates too much SSI in the extratropics and too little in the tropics, especially in the summer hemisphere. These discrepancies reach magnitudes of 60 W/sq m and more. The discrepancies are particularly large in the July case off the western coast of North America. Positive and negative discrepancies in SSI are shown to be consistent with discrepancies in planetary albedo.

Ocean Lidar Measurements of Beam Attenuation and a Roadmap to Accurate Phytoplankton Biomass Estimates

NASA Astrophysics Data System (ADS)

Hu, Yongxiang; Behrenfeld, Mike; Hostetler, Chris; Pelon, Jacques; Trepte, Charles; Hair, John; Slade, Wayne; Cetinic, Ivona; Vaughan, Mark; Lu, Xiaomei; Zhai, Pengwang; Weimer, Carl; Winker, David; Verhappen, Carolus C.; Butler, Carolyn; Liu, Zhaoyan; Hunt, Bill; Omar, Ali; Rodier, Sharon; Lifermann, Anne; Josset, Damien; Hou, Weilin; MacDonnell, David; Rhew, Ray

2016-06-01

Beam attenuation coefficient, c, provides an important optical index of plankton standing stocks, such as phytoplankton biomass and total particulate carbon concentration. Unfortunately, c has proven difficult to quantify through remote sensing. Here, we introduce an innovative approach for estimating c using lidar depolarization measurements and diffuse attenuation coefficients from ocean color products or lidar measurements of Brillouin scattering. The new approach is based on a theoretical formula established from Monte Carlo simulations that links the depolarization ratio of sea water to the ratio of diffuse attenuation Kd and beam attenuation C (i.e., a multiple scattering factor). On July 17, 2014, the CALIPSO satellite was tilted 30° off-nadir for one nighttime orbit in order to minimize ocean surface backscatter and demonstrate the lidar ocean subsurface measurement concept from space. Depolarization ratios of ocean subsurface backscatter are measured accurately. Beam attenuation coefficients computed from the depolarization ratio measurements compare well with empirical estimates from ocean color measurements. We further verify the beam attenuation coefficient retrievals using aircraft-based high spectral resolution lidar (HSRL) data that are collocated with in-water optical measurements.

Antarctic icebergs melt over the Southern Ocean : Climatology and impact on sea ice

NASA Astrophysics Data System (ADS)

Merino, Nacho; Le Sommer, Julien; Durand, Gael; Jourdain, Nicolas C.; Madec, Gurvan; Mathiot, Pierre; Tournadre, Jean

2016-08-01

Recent increase in Antarctic freshwater release to the Southern Ocean is suggested to contribute to change in water masses and sea ice. However, climate models differ in their representation of the freshwater sources. Recent improvements in altimetry-based detection of small icebergs and in estimates of the mass loss of Antarctica may help better constrain the values of Antarctic freshwater releases. We propose a model-based seasonal climatology of iceberg melt over the Southern Ocean using state-of-the-art observed glaciological estimates of the Antarctic mass loss. An improved version of a Lagrangian iceberg model is coupled with a global, eddy-permitting ocean/sea ice model and compared to small icebergs observations. Iceberg melt increases sea ice cover, about 10% in annual mean sea ice volume, and decreases sea surface temperature over most of the Southern Ocean, but with distinctive regional patterns. Our results underline the importance of improving the representation of Antarctic freshwater sources. This can be achieved by forcing ocean/sea ice models with a climatological iceberg fresh-water flux.

A global reference model of Curie-point depths based on EMAG2

NASA Astrophysics Data System (ADS)

Li, Chun-Feng; Lu, Yu; Wang, Jian

2017-03-01

In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C)-1 for the ocean and K = ~2.5 W(m°C)-1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m2, leading to a global heat loss ranging from ~34.6 to 36.6 TW.

An Innovative Concept for Spacebased Lidar Measurement of Ocean Carbon Biomass

NASA Technical Reports Server (NTRS)

Hu, Yongxiang; Behrenfeld, Michael; Hostetler, Chris; Pelon, Jacques; Trepte, Charles; Hair, John; Slade, Wayne; Cetinic, Ivona; Vaughan, Mark; Lu, Xiaomei;

Robustness of observation-based decadal sea level variability in the Indo-Pacific Ocean

NASA Astrophysics Data System (ADS)

Nidheesh, A. G.; Lengaigne, M.; Vialard, J.; Izumo, T.; Unnikrishnan, A. S.; Meyssignac, B.; Hamlington, B.; de Boyer Montegut, C.

2017-07-01

We examine the consistency of Indo-Pacific decadal sea level variability in 10 gridded, observation-based sea level products for the 1960-2010 period. Decadal sea level variations are robust in the Pacific, with more than 50% of variance explained by decadal modulation of two flavors of El Niño-Southern Oscillation (classical ENSO and Modoki). Amplitude of decadal sea level variability is weaker in the Indian Ocean than in the Pacific. All data sets indicate a transmission of decadal sea level signals from the western Pacific to the northwest Australian coast through the Indonesian throughflow. The southern tropical Indian Ocean sea level variability is associated with decadal modulations of ENSO in reconstructions but not in reanalyses or in situ data set. The Pacific-independent Indian Ocean decadal sea level variability is not robust but tends to be maximum in the southwestern tropical Indian Ocean. The inconsistency of Indian Ocean decadal variability across the sea level products calls for caution in making definitive conclusions on decadal sea level variability in this basin.

A global reference model of Curie-point depths based on EMAG2.

PubMed

Li, Chun-Feng; Lu, Yu; Wang, Jian

2017-03-21

In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C) -1 for the ocean and K = ~2.5 W(m°C) -1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m 2 , leading to a global heat loss ranging from ~34.6 to 36.6 TW.

Retrieval of Ocean Subsurface Particulate Backscattering Coefficient from Space-Borne CALIOP Lidar Measurement

NASA Technical Reports Server (NTRS)

Lu, Xiaomei; Hu, Yongxiang; Pelon, Jacques; Trepte, Chip; Liu, Katie; Rodier, Sharon; Zeng, Shan; Luckher, Patricia; Verhappen, Ron; Wilson, Jamie;

Supporting Teachers' Use of a Project-Based Learning Environment in Ocean Science: Web-Based Educative Curriculum Materials

ERIC Educational Resources Information Center

Duncan, Ravit Golan; El-Moslimany, Hebbah; McDonnell, Janice; Lichtenwalner, Sage

2011-01-01

The development of inquiry and project-based materials is challenging in many ways, not the least of which is the design of supports for teachers implementing such materials. We report on the design of educative and just-in-time teacher supports for an online project-based unit in ocean science. The teacher supports were visible as tabs on the…

Interaction between the compact tori and coated stainless-steel samples

NASA Astrophysics Data System (ADS)

Rohollahi, A.; Khatir, S.; Xiao, C.; Hirose, A.

2017-02-01

The surface damages due to the transient heat load and particle fluxes on the surface of the coated stainless-steel (SS) samples have been investigated. University of Saskatchewan compact torus injector has been used to inject the high heat load and the particle flux on the surface of stainless samples with three different types of coatings. The type 1 samples were made from a SS plate coated by tungsten. The other two samples had additional films of either nickel (type 2) or chromium (type 3) on the type 1 samples. The vacuum plasma spray technique has been applied for the coating of the samples. Surface cracking and melting have been observed on the surface after the samples were impacted by many high-speed and dense plasmoids.

Infrared-thermography imaging system multiapplications for manufacturing

NASA Astrophysics Data System (ADS)

Stern, Sharon A.

1990-03-01

Imaging systems technology has been utilized traditionally for diagnosing structural envelope or insulation problems in the general thermographic comunity. Industrially, new applications for utilizing thermal imaging technology have been developed i n pred i cti ve/preventi ye mai ntenance and prod uct moni tori ng prociures at Eastman Kodak Company, the largest photographic manufacturering producer in the world. In the manufacturing processes used at Eastman Kodak Company, new applications for thermal imaging include: (1) Fluid transfer line insulation (2) Web coating drying uniformity (3) Web slitter knives (4) Heating/cooling coils (5) Overheated tail bearings, and (6) Electrical phase imbalance. The substantial cost benefits gained from these applications of infrared thermography substantiate the practicality of this approach and indicate the desirability of researching further appl i cati ons.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozlov, I K

In this paper we study topological properties of an integrable case for Euler's equations on the Lie algebra so(4), which can be regarded as an analogue of the classical Kovalevskaya case in rigid body dynamics. In particular, for all values of the parameters of the system under consideration, the bifurcation diagrams of the momentum mapping are constructed, the types of critical points of rank 0 are determined, the bifurcations of Liouville tori are described, and the loop molecules are computed for all singular points of the bifurcation diagrams. It follows from the obtained results that some topological properties of the classicalmore » Kovalevskaya case can be obtained from the corresponding properties of the considered integrable case on the Lie algebra so(4) by taking a natural limit. Bibliography: 21 titles.« less

Ocean, Land and Meteorology Studies Using Space-Based Lidar Measurements

NASA Technical Reports Server (NTRS)

Hu,Yongxiang

2009-01-01

CALIPSO's main mission objective is studying the climate impact of clouds and aerosols in the atmosphere. CALIPSO also collects information about other components of the Earth's ecosystem, such as oceans and land. This paper introduces the physics concepts and presents preliminary results for the valueadded CALIPSO Earth system science products. These include ocean surface wind speeds, column atmospheric optical depths, ocean subsurface backscatter, land surface elevations, atmospheric temperature profiles, and A-train data fusion products.

Vulnerability of Population and Transportation Infrastructure at the East Bank of Delaware Bay Due to Coastal Flooding in Sea-Level Rise Conditions

DTIC Science & Technology

2013-04-30

resulting impact on residents and transportation infrastructure. The three-dimensional coastal ocean model FVCOM coupled with a two-dimensional...shallow water model is used to simulate hydrodynamic flooding from coastal ocean water with fine-resolution meshes, and a topography-based hydrologic... ocean model FVCOM coupled with a two-dimensional shallow water model is used to simulate hydrodynamic flooding from coastal ocean water with fine

33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The area. All of the waters of Camp Pendleton Boat...

33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The area. All of the waters of Camp Pendleton Boat...

33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The area. All of the waters of Camp Pendleton Boat...

33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The area. All of the waters of Camp Pendleton Boat...

33 CFR 334.910 - Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. 334.910 Section 334.910... AND RESTRICTED AREA REGULATIONS § 334.910 Pacific Ocean, Camp Pendleton Boat Basin, U.S. Marine Corps Base, Camp Pendleton, Calif.; restricted area. (a) The area. All of the waters of Camp Pendleton Boat...

Design and implementation of a 3D ocean virtual reality and visualization engine

NASA Astrophysics Data System (ADS)

Chen, Ge; Li, Bo; Tian, Fenglin; Ji, Pengbo; Li, Wenqing

2012-12-01

In this study, a 3D virtual reality and visualization engine for rendering the ocean, named VV-Ocean, is designed for marine applications. The design goals of VV-Ocean aim at high fidelity simulation of ocean environment, visualization of massive and multidimensional marine data, and imitation of marine lives. VV-Ocean is composed of five modules, i.e. memory management module, resources management module, scene management module, rendering process management module and interaction management module. There are three core functions in VV-Ocean: reconstructing vivid virtual ocean scenes, visualizing real data dynamically in real time, imitating and simulating marine lives intuitively. Based on VV-Ocean, we establish a sea-land integration platform which can reproduce drifting and diffusion processes of oil spilling from sea bottom to surface. Environment factors such as ocean current and wind field have been considered in this simulation. On this platform oil spilling process can be abstracted as movements of abundant oil particles. The result shows that oil particles blend with water well and the platform meets the requirement for real-time and interactive rendering. VV-Ocean can be widely used in ocean applications such as demonstrating marine operations, facilitating maritime communications, developing ocean games, reducing marine hazards, forecasting the weather over oceans, serving marine tourism, and so on. Finally, further technological improvements of VV-Ocean are discussed.

Investigation of 2-Dimensional Isotropy of Under-Ice Roughness in the Beaufort Gyre and Implications for Mixed Layer Ocean Turbulence

DTIC Science & Technology

2008-03-01

this roughness is important for numerical modeling and prediction of the Arctic air-ice-ocean system, which will play a significant role as the US Navy...is important for numerical modeling and prediction of the Arctic air-ice-ocean system, which will play a significant role as the US Navy increases... Model 1 is based on a sequence of plane parallel layers each with a constant gradient whereas Model 2 is based on a series of flat layers of

The Blue Marble

NASA Technical Reports Server (NTRS)

2002-01-01

This spectacular Moderate Resolution Imaging Spectroradiometer (MODIS) 'blue marble' image is based on the most detailed collection of true-color imagery of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet. Most of the information contained in this image came from MODIS, illustrating MODIS' outstanding capacity to act as an integrated tool for observing a variety of terrestrial, oceanic, and atmospheric features of the Earth. The land and coastal ocean portions of this image is based on surface observations collected from June through September 2001 and combined, or composited, every eight days to compensate for clouds that might block the satellite's view on any single day. Global ocean color (or chlorophyll) data was used to simulate the ocean surface. MODIS doesn't measure 3-D features of the Earth, so the surface observations were draped over topographic data provided by the U.S. Geological Survey EROS Data Center. MODIS observations of polar sea ice were combined with observations of Antarctica made by the National Oceanic and Atmospheric Administration's AVHRR sensor-the Advanced Very High Resolution Radiometer. The cloud image is a composite of two days of MODIS imagery collected in visible light wavelengths and a third day of thermal infra-red imagery over the poles. A large collection of imagery based on the blue marble in a variety of sizes and formats, including animations and the full (1 km) resolution imagery, is available at the Blue Marble page. Image by Reto Stockli, Render by Robert Simmon. Based on data from the MODIS Science Team

Remote sensing of ocean surface currents: a review of what is being observed and what is being assimilated

NASA Astrophysics Data System (ADS)

Isern-Fontanet, Jordi; Ballabrera-Poy, Joaquim; Turiel, Antonio; García-Ladona, Emilio

2017-10-01

Ocean currents play a key role in Earth's climate - they impact almost any process taking place in the ocean and are of major importance for navigation and human activities at sea. Nevertheless, their observation and forecasting are still difficult. First, no observing system is able to provide direct measurements of global ocean currents on synoptic scales. Consequently, it has been necessary to use sea surface height and sea surface temperature measurements and refer to dynamical frameworks to derive the velocity field. Second, the assimilation of the velocity field into numerical models of ocean circulation is difficult mainly due to lack of data. Recent experiments that assimilate coastal-based radar data have shown that ocean currents will contribute to increasing the forecast skill of surface currents, but require application in multidata assimilation approaches to better identify the thermohaline structure of the ocean. In this paper we review the current knowledge in these fields and provide a global and systematic view of the technologies to retrieve ocean velocities in the upper ocean and the available approaches to assimilate this information into ocean models.

Constraining global air-sea gas exchange for CO2 with recent bomb 14C measurements

NASA Astrophysics Data System (ADS)

Sweeney, Colm; Gloor, Emanuel; Jacobson, Andrew R.; Key, Robert M.; McKinley, Galen; Sarmiento, Jorge L.; Wanninkhof, Rik

2007-06-01

The 14CO2 released into the stratosphere during bomb testing in the early 1960s provides a global constraint on air-sea gas exchange of soluble atmospheric gases like CO2. Using the most complete database of dissolved inorganic radiocarbon, DI14C, available to date and a suite of ocean general circulation models in an inverse mode we recalculate the ocean inventory of bomb-produced DI14C in the global ocean and confirm that there is a 25% decrease from previous estimates using older DI14C data sets. Additionally, we find a 33% lower globally averaged gas transfer velocity for CO2 compared to previous estimates (Wanninkhof, 1992) using the NCEP/NCAR Reanalysis 1 1954-2000 where the global mean winds are 6.9 m s-1. Unlike some earlier ocean radiocarbon studies, the implied gas transfer velocity finally closes the gap between small-scale deliberate tracer studies and global-scale estimates. Additionally, the total inventory of bomb-produced radiocarbon in the ocean is now in agreement with global budgets based on radiocarbon measurements made in the stratosphere and troposphere. Using the implied relationship between wind speed and gas transfer velocity ks = 0.27(Sc/660)-0.5 and standard partial pressure difference climatology of CO2 we obtain an net air-sea flux estimate of 1.3 ± 0.5 PgCyr-1 for 1995. After accounting for the carbon transferred from rivers to the deep ocean, our estimate of oceanic uptake (1.8 ± 0.5 PgCyr-1) compares well with estimates based on ocean inventories, ocean transport inversions using ocean concentration data, and model simulations.

Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle

NASA Astrophysics Data System (ADS)

McNeil, B.

2016-02-01

Elevated carbon dioxide concentrations in seawater (hypercapnia) can induce neurological, physiological and behavioural deficiencies in marine animals. Prediction of the onset and evolution of hypercapnia in the ocean requires a good understanding of annual oceanic carbon dioxide variability, but relevant global observational data are sparse. Here we diagnose global ocean patterns of monthly carbon variability based on observations that allow us to examine the evolution of surface ocean CO2 levels over the entire annual cycle under increasing atmospheric CO2 concentrations. We find that some oceanic regions undergo an up to 10-fold amplification of the natural cycle of CO2 by 2100, if atmospheric carbon dioxide concentrations continue to rise throughout this century (RCP8.5). Projections from a suite of Earth System Climate Models are broadly consistent with the findings from our data based approach. Our predicted amplification in the annual CO2 cycle displays distinct global patterns that may expose major fisheries in the Southern, Pacific and North Atlantic Oceans to high CO2 events many decades earlier than expected from average atmospheric CO2 concentrations. We suggest that these ocean 'CO2 hotspots' evolve as a combination of the strong seasonal dynamics of CO2 and the long-term effective storage of anthropogenic CO2 that lowers the buffer capacity in those regions, causing a non-linear CO2 amplification over the annual cycle. The onset of ocean hypercapnia events (pCO2 >1000 µatm) is forecast for atmospheric CO2 concentrations that exceed 650 ppm, with hypercapnia spreading to up to one half of the surface ocean by the year 2100 under a high-emissions scenario (RCP8.5) with potential implications for fisheries over the coming century.

Local Observations, Global Connections: An Educational Program Using Ocean Networks Canada's Community-Based Observatories

NASA Astrophysics Data System (ADS)

Pelz, M.; Hoeberechts, M.; Ewing, N.; Davidson, E.; Riddell, D. J.

2014-12-01

Schools on Canada's west coast and in the Canadian Arctic are participating in the pilot year of a novel educational program based on analyzing, understanding and sharing ocean data collected by cabled observatories. The core of the program is "local observations, global connections." First, students develop an understanding of ocean conditions at their doorstep through the analysis of community-based observatory data. Then, they connect that knowledge with the health of the global ocean by engaging with students at other schools participating in the educational program and through supplemental educational resources. Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates cabled ocean observatories which supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea. This Internet connectivity permits researchers, students and members of the public to download freely available data on their computers anywhere around the globe, in near real-time. In addition to the large NEPTUNE and VENUS cabled observatories off the coast of Vancouver Island, British Columbia, ONC has been installing smaller, community-based cabled observatories. Currently two are installed: one in Cambridge Bay, Nunavut and one at Brentwood College School, on Mill Bay in Saanich Inlet, BC. Several more community-based observatories are scheduled for installation within the next year. The observatories support a variety of subsea instruments, such as a video camera, hydrophone and water quality monitor and shore-based equipment including a weather station and a video camera. Schools in communities hosting an observatory are invited to participate in the program, alongside schools located in other coastal and inland communities. Students and teachers access educational material and data through a web portal, and use video conferencing and social media tools to communicate their findings. A series of lesson plans introduces the teachers and students to cabled observatory technology and instrumentation, including technical aspects and their value in monitoring changing ocean conditions. This presentation will describe the program in more detail and report on our experiences in the first months of the pilot year.

NOAA Propagation Database Value in Tsunami Forecast Guidance

NASA Astrophysics Data System (ADS)

Eble, M. C.; Wright, L. M.

2016-02-01

The National Oceanic and Atmospheric Administration (NOAA) Center for Tsunami Research (NCTR) has developed a tsunami forecasting capability that combines a graphical user interface with data ingestion and numerical models to produce estimates of tsunami wave arrival times, amplitudes, current or water flow rates, and flooding at specific coastal communities. The capability integrates several key components: deep-ocean observations of tsunamis in real-time, a basin-wide pre-computed propagation database of water level and flow velocities based on potential pre-defined seismic unit sources, an inversion or fitting algorithm to refine the tsunami source based on the observations during an event, and tsunami forecast models. As tsunami waves propagate across the ocean, observations from the deep ocean are automatically ingested into the application in real-time to better define the source of the tsunami itself. Since passage of tsunami waves over a deep ocean reporting site is not immediate, we explore the value of the NOAA propagation database in providing placeholder forecasts in advance of deep ocean observations. The propagation database consists of water elevations and flow velocities pre-computed for 50 x 100 [km] unit sources in a continuous series along all known ocean subduction zones. The 2011 Japan Tohoku tsunami is presented as the case study

Plausible surface models for Titan

NASA Technical Reports Server (NTRS)

Lunine, Jonathan I.

1992-01-01

Current understanding of the nature of Titan's surface and some new ideas for explaining the curious radar returns from Saturn's largest satellite are reviewed. Pre-Voyager models of the surface, based largely on cosmochemistry and the discovery of atmospheric methane, allowed for a range of possibilities, including pure methane oceans. The Voyager 1 flyby ruled out this last possibility, replacing it with compelling observational arguments in favor of a mixed light hydrocarbon and nitrogen ocean. Ground based radar observations indicated a surprisingly reflective surface which is inconsistent with a hydrocarbon ocean and more reminiscent of the Galilean Satellites. Nonetheless, passive radiometric measurements of the surface do not support the notion that Titan's surface is like that of the Galilean satellites. One of the arguments against hydrocarbon oceans reflecting radar energy is that most solid, complex hydrocarbon and nitriles will be denser than the liquid and sink. Nonetheless, many of the aerosol species will coagulate in highly nonspherical patterns, and some species probably polymerize in long chains. Such chains will have very low sedimendation velocities in the ocean and may remain near the surface through ocean mixing process. The prospect of an oceanic 'soup' of polar polymers acting as volume reflectors at radio wevelengths suggests that the interpretation of radar observations needs evaluation.

The Correlation Between Atmospheric Dust Deposition to the Surface Ocean and SeaWiFS Ocean Color: A Global Satellite-Based Analysis

NASA Technical Reports Server (NTRS)

Erickson, D. J., III; Hernandez, J.; Ginoux, P.; Gregg, W.; Kawa, R.; Behrenfeld, M.; Esaias, W.; Einaudi, Franco (Technical Monitor)

2000-01-01

Since the atmospheric deposition of iron has been linked to primary productivity in various oceanic regions, we have conducted an objective study of the correlation of dust deposition and satellite remotely sensed surface ocean chlorophyll concentrations. We present a global analysis of the correlation between atmospheric dust deposition derived from a satellite-based 3-D atmospheric transport model and SeaWiFs estimates of ocean color. We use the monthly mean dust deposition fields of Ginoux et al. which are based on a global model of dust generation and transport. This model is driven by atmospheric circulation from the Data Assimilation Office (DAO) for the period 1995-1998. This global dust model is constrained by several satellite estimates of standard circulation characteristics. We then perform an analysis of the correlation between the dust deposition and the 1998 SeaWIFS ocean color data for each 2.0 deg x 2.5 deg lat/long grid point, for each month of the year. The results are surprisingly robust. The region between 40 S and 60 S has correlation coefficients from 0.6 to 0.95, statistically significant at the 0.05 level. There are swaths of high correlation at the edges of some major ocean current systems. We interpret these correlations as reflecting areas that have shear related turbulence bringing nitrogen and phosphorus from depth into the surface ocean, and the atmospheric supply of iron provides the limiting nutrient and the correlation between iron deposition and surface ocean chlorophyll is high. There is a region in the western North Pacific with high correlation, reflecting the input of Asian dust to that region. The southern hemisphere has an average correlation coefficient of 0.72 compared that in the northern hemisphere of 0.42 consistent with present conceptual models of where atmospheric iron deposition may play a role in surface ocean biogeochemical cycles. The spatial structure of the correlation fields will be discussed within the context of guiding the design of field programs.

Large-Scale Oceanic Variability Associated with the Madden-Julian Oscillation during the CINDY/DYNAMO Field Campaign from Satellite Observations

DTIC Science & Technology

2013-04-29

during the field campaign. For the first time, it is demonstrated that subseasonal SSS variations in the central Indian Ocean can be monitored by Aquarius...westerlies were observed in both Northern and Southern Hemispheres in the central and eastern Indian Oceans. The anomalous SSH associated with strong...it is demonstrated that subseasonal SSS variations in the central Indian Ocean can be monitored by Aquarius measurements based on the comparison

Integration of an Emerging Highly Sensitive Optical CO2 Sensor for Ocean Monitoring on an Existing Data Acquisition System SeaKeeper 1000 (trademark)

DTIC Science & Technology

2012-09-30

be deployed in geat numbers to autonomously monitor the overall patterns of CO2 emissions and ocean acidification . OBJECTIVES  Meet the...Integration of an Emerging Highly Sensitive Optical CO2 Sensor for Ocean Monitoring on an Existing Data Acquisition System SeaKeeper 1000TM Annual...challenging requirements for ocean pCO2 monitoring using an innovative sensor design based on high sensitivity fluorescence detection.  Assemble the system

Integration of an Emerging Highly Sensitive Optical CO2 Sensor for Ocean Monitoring on an Existing Data Acquisition System SeaKeeper 1000(TM)

DTIC Science & Technology

2011-09-30

be deployed in geat numbers to autonomously monitor the overall patterns of CO2 emissions and ocean acidification . OBJECTIVES  Meet the...Integration of an Emerging Highly Sensitive Optical CO2 Sensor for Ocean Monitoring on an Existing Data Acquisition System SeaKeeper 1000TM Annual...challenging requirements for ocean pCO2 monitoring using an innovative sensor design based on high sensitivity fluorescence detection.  Assemble the system

NOAA Office of Exploration and Research > Exploration > Overview

Science.gov Websites

archaeological aspects of the ocean in the three dimensions of space and in time. The Panel's recommendations limited to) marine biodiversity, the Arctic Ocean, the Gulf of Mexico, exploring the ocean through time exploration, giving shore-based explorers of all kinds and ages access to the excitement of real-time

Aquantis Ocean Current Turbine Development Project Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleming, Alex J.

2014-08-23

The Aquantis® Current Plane (“C-Plane”) technology developed by Dehlsen Associates, LLC (DA) and Aquantis, Inc. is an ocean current turbine designed to extract kinetic energy from ocean currents. The technology is capable of achieving competitively priced base-load, continuous, and reliable power generation from a source of renewable energy not before possible in this scale or form.

Analysis of global oceanic rainfall from microwave data

NASA Technical Reports Server (NTRS)

Rao, M.

1978-01-01

A Global Rainfall Atlas was prepared from Nimbus 5 ESMR data. The Atlas includes global oceanic rainfall maps based on weekly, monthly and seasonal averages, complete through the end of 1975. Similar maps for 1973 and 1974 were studied. They reveal several previously unknown areas of enhanced rainfall and preliminary data on interannual variability of oceanic rainfall.

Land-ocean contrast on electrical characteristics of lightning discharge derived from satellite optical measurements

NASA Astrophysics Data System (ADS)

Adachi, T.; Said, R.; Cummer, S. A.; Li, J.; Takahashi, Y.; Hsu, R.; Su, H.; Chen, A. B.; Mende, S. B.; Frey, H. U.

2010-12-01

Comparative studies on the electrical properties of oceanic and continental lightning are crucial to elucidate air discharge processes occurring under different conditions. Past studies however have primarily focused on continental lightning because of the limited coverage of ground-based instruments. Recent satellite measurements by FORMOSAT-2/ISUAL provided a new way to survey the global characteristics of lightning and transient luminous events regardless of land and ocean. In this study, we analyze ISUAL/spectrophotometer data to clarify the electrical properties of lightning on a global level. Based on the results obtained by Cummer et al. [2006] and Adachi et al. [2009], the OI-777.4nm emission intensity is used to infer lightning electrical parameters. Results show a clear land-ocean contrast on the parameters of lightning discharge: in oceanic lightning, peak luminosity is 60 % higher and the time scale of return stroke is 30 % shorter. These results suggest higher peak current in oceanic lightning, which is consistent with the fact that elves, EMP-driven phenomena, also tend to occur over the ocean [Chen et al., 2008]. Further analysis of lightning events occurring around the Caribbean Sea shows that the transition-line of lightning electrical properties is precisely located along the coastline. We suggest that the differences in these electrical properties may be due to the boundary conditions (conductivity, surface terrain, etc). In this talk, based on the calibration with NLDN and Duke magnetometer data, current moment change and charge moment change will be globally evaluated using a complete set of the ISUAL-observed lightning events.

Data-based estimates of the ocean carbon sink variability - results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)

NASA Astrophysics Data System (ADS)

Rödenbeck, Christian; Bakker, Dorothee; Gruber, Nicolas; Iida, Yosuke; Jacobson, Andy; Jones, Steve; Landschützer, Peter; Metzl, Nicolas; Nakaoka, Shin-ichiro; Olsen, Are; Park, Geun-Ha; Peylin, Philippe; Rodgers, Keith; Sasse, Tristan; Schuster, Ute; Shutler, James; Valsala, Vinu; Wanninkhof, Rik; Zeng, Jiye

2016-04-01

Using measurements of the surface-ocean COtwo partial pressure (pCOtwo) from the SOCAT and LDEO data bases and 14 different pCOtwo mapping methods recently collated by the Surface Ocean pCOtwo Mapping intercomparison (SOCOM) initiative, variations in regional and global sea-air COtwo fluxes are investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCOtwo seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the Eastern equatorial Pacific. Despite considerable spread in the detailed variations, mapping methods that fit the data more closely also tend to agree more closely with each other in regional averages. Encouragingly, this includes mapping methods belonging to complementary types - taking variability either directly from the pCOtwo data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea-air COtwo flux of IAVampl (standard deviation over AnalysisPeriod), which is larger than simulated by biogeochemical process models. On a decadal perspective, the global ocean COtwo uptake is estimated to have gradually increased since about 2000, with little decadal change prior to that. The weighted mean net global ocean COtwo sink estimated by the SOCOM ensemble is -1.75 UPgCyr (AnalysisPeriod), consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends. Using data-based sea-air COtwo fluxes in atmospheric COtwo inversions also helps to better constrain land-atmosphere COtwo fluxes.

Influences of Ocean Thermohaline Stratification on Arctic Sea Ice

NASA Astrophysics Data System (ADS)

Toole, J. M.; Timmermans, M.-L.; Perovich, D. K.; Krishfield, R. A.; Proshutinsky, A.; Richter-Menge, J. A.

2009-04-01

The Arctic Ocean's surface mixed layer constitutes the dynamical and thermodynamical link between the sea ice and the underlying waters. Wind stress, acting directly on the surface mixed layer or via wind-forced ice motion, produce surface currents that can in turn drive deep ocean flow. Mixed layer temperature is intimately related to basal sea ice growth and melting. Heat fluxes into or out of the surface mixed layer can occur at both its upper and lower interfaces: the former via air-sea exchange at leads and conduction through the ice, the latter via turbulent mixing and entrainment at the layer base. Variations in Arctic Ocean mixed layer properties are documented based on more than 16,000 temperature and salinity profiles acquired by Ice-Tethered Profilers since summer 2004 and analyzed in conjunction with sea ice observations from Ice Mass Balance Buoys and atmospheric heat flux estimates. Guidance interpreting the observations is provided by a one-dimensional ocean mixed layer model. The study focuses attention on the very strong density stratification about the mixed layer base in the Arctic that, in regions of sea ice melting, is increasing with time. The intense stratification greatly impedes mixed layer deepening by vertical convection and shear mixing, and thus limits the flux of deep ocean heat to the surface that could influence sea ice growth/decay. Consistent with previous work, this study demonstrates that the Arctic sea ice is most sensitive to changes in ocean mixed layer heat resulting from fluxes across its upper (air-sea and/or ice-water) interface.

Rigorous Characterisation of a Novel, Statistically-Based Ocean Colour Algorithm for the PACE Mission

NASA Astrophysics Data System (ADS)

Craig, S. E.; Lee, Z.; Du, K.; Lin, J.

2016-02-01

An approach based on empirical orthogonal function (EOF) analysis of ocean colour spectra has been shown to accurately derive inherent optical properties (IOPs) and chlorophyll concentration in scenarios, such as optically complex waters, where standard algorithms often perform poorly. The algorithm has been successfully used in a number of regional applications, and has also shown promise in a global implementation based on the NASA NOMAD data set. Additionally, it has demonstrated the unique ability to derive ocean colour products from top of atmosphere (TOA) signals with either no or minimal atmospheric correction applied. Due to its high potential for use over coastal and inland waters, the EOF approach is currently being rigorously characterised as part of a suite of approaches that will be used to support the new NASA ocean colour mission, PACE (Pre-Aerosol, Clouds and ocean Ecosystem). A major component in this model characterisation is the generation of a synthetic TOA data set using a coupled ocean-atmosphere radiative transfer model, which has been run to mimic PACE spectral resolution, and under a wide range of geographical locations, water constituent concentrations, and sea surface and atmospheric conditions. The resulting multidimensional data set will be analysed, and results presented on the sensitivity of the model to various combinations of parameters, and preliminary conclusions made regarding the optimal implementation strategy of this promising approach (e.g. on a global, optical water type or regional basis). This will provide vital guidance for operational implementation of the model for both existing satellite ocean colour sensors and the upcoming PACE mission.

Autonomous observing platform CO2 data shed new light on the Southern Ocean carbon cycle

NASA Astrophysics Data System (ADS)

Olsen, Are

2017-06-01

While the number of surface ocean CO2 partial pressure (pCO2) measurements has soared the recent decades, the Southern Ocean remains undersampled. Williams et al. (2017, https://doi.org/10.1002/2016GB005541) now present pCO2 estimates based on data from pH-sensor equipped Bio-Argo floats, which have been measuring in the Southern Ocean since 2014. The authors demonstrate the utility of these data for understanding the carbon cycle in this region, which has a large influence on the distribution of CO2 between the ocean and atmosphere. Biogeochemical sensors deployed on autonomous platforms hold the potential to shape our view of the ocean carbon cycle in the coming decades.

Physics-based coastal current tomographic tracking using a Kalman filter.

PubMed

Wang, Tongchen; Zhang, Ying; Yang, T C; Chen, Huifang; Xu, Wen

2018-05-01

Ocean acoustic tomography can be used based on measurements of two-way travel-time differences between the nodes deployed on the perimeter of the surveying area to invert/map the ocean current inside the area. Data at different times can be related using a Kalman filter, and given an ocean circulation model, one can in principle now cast and even forecast current distribution given an initial distribution and/or the travel-time difference data on the boundary. However, an ocean circulation model requires many inputs (many of them often not available) and is unpractical for estimation of the current field. A simplified form of the discretized Navier-Stokes equation is used to show that the future velocity state is just a weighted spatial average of the current state. These weights could be obtained from an ocean circulation model, but here in a data driven approach, auto-regressive methods are used to obtain the time and space dependent weights from the data. It is shown, based on simulated data, that the current field tracked using a Kalman filter (with an arbitrary initial condition) is more accurate than that estimated by the standard methods where data at different times are treated independently. Real data are also examined.

Oceanic Flights and Airspace: Improving Efficiency by Trajectory-Based Operations

NASA Technical Reports Server (NTRS)

Fernandes, Alicia Borgman; Rebollo, Juan; Koch, Michael

2016-01-01

Oceanic operations suffer from multiple inefficiencies, including pre-departure planning that does not adequately consider uncertainty in the proposed trajectory, restrictions on the routes that a flight operator can choose for an oceanic crossing, time-consuming processes and procedures for amending en route trajectories, and difficulties exchanging data between Flight Information Regions (FIRs). These inefficiencies cause aircraft to fly suboptimal trajectories, burning fuel and time that could be conserved. A concept to support integration of existing and emerging capabilities and concepts is needed to transition to an airspace system that employs Trajectory Based Operations (TBO) to improve efficiency and safety in oceanic operations. This paper describes such a concept and the results of preliminary activities to evaluate the concept, including a stakeholder feedback activity, user needs analysis, and high level benefits analysis.

Ocean Surface Carbon Dioxide Fugacity Observed from Space

NASA Technical Reports Server (NTRS)

Liu, W. Timothy; Xie, Xiaosu

2014-01-01

We have developed and validated a statistical model to estimate the fugacity (or partial pressure) of carbon dioxide (CO2) at sea surface (pCO2sea) from space-based observations of sea surface temperature (SST), chlorophyll, and salinity. More than a quarter million in situ measurements coincident with satellite data were compiled to train and validate the model. We have produced and made accessible 9 years (2002-2010) of the pCO2sea at 0.5 degree resolutions daily over the global ocean. The results help to identify uncertainties in current JPL Carbon Monitoring System (CMS) model-based and bottom-up estimates over the ocean. The utility of the data to reveal multi-year and regional variability of the fugacity in relation to prevalent oceanic parameters is demonstrated.

Long-term marine litter monitoring in the remote Great Australian Bight, South Australia.

PubMed

Edyvane, K S; Dalgetty, A; Hone, P W; Higham, J S; Wace, N M

2004-06-01

The Anxious Bay beach litter clearance is the longest running annual survey of ocean-based litter in Australia. It's remoteness from centres of human population and location (with respect to prevailing winds and currents) make it an ideal place for monitoring ocean or ship-based litter in Australia's southern oceans and particularly, the Great Australian Bight. Over the 1991-1999 period, a large but gradual decline in the amount of beach washed litter was recorded (with minor peaks recorded during the 1992 and 1994 surveys). Beach washed litter decreased by approximately 86%, from 344 kg recorded in 1991 (13.2 kg/km) to 49 kg in 1999 (i.e. 1.9 kg/km), reaching a maximum of 390 kg in 1992 (or 15 kg/km of beach). However, a sharp increase in litter was recorded in 2000 (i.e. 252 kg or 9.7 kg/km). This increase in litter yield in 2000 is probably due to stronger than average onshore surface flow (or Ekman Transport) in the western Eyre Peninsula and Bight region. Prior to the survey in 2000, the results appeared to indicate that ocean litter on Anxious Bay beach was beginning to level out at around 50-70 kg/year (i.e. 2-3 kg/km). As the beach surveys involve the assumption that the beach is completely cleared of litter, this may represent a baseline level for ocean-based litter in the region. The yields and type of litter collected from the annual survey indicates that the majority of litter washed ashore originates from commercial fishing activities within the Great Australian Bight. Most of the fishing-related litter was directly sourced to the Southern Rock Lobster Fishery (i.e. bait buckets, baskets, pots), the Great Australian Bight Trawl Fishery (i.e. codends, trawl nets) and the Southern Shark Fishery (i.e. monofilament gillnets and longlines). Between 1994 and 1999, large reductions were observed in the amount of bait straps (77% reduction), lobster bait baskets/buckets (86% reduction), nets/ropes (62% reduction) and floats/buoys (83% reduction). Significantly, fishing-related litter in the Bight has reduced at a slower rate than domestic litter. While the level of glass and soft plastics on the beach have both reduced by almost 93% (i.e. 103-7 kg and 119-8 kg, respectively), the level of hard plastics, has diminished at a slower rate, with reductions of only 75% (i.e. 122-30 kg). Some fisheries (i.e. rock lobster, Southern Shark Fishery) have shown marked reductions in fishing-related litter. This is probably due, to some extent, to significant reductions in fishing effort in the region, although this requires further investigation. The information from the Anxious Bay beach litter survey is crucial in monitoring trends in ocean litter in Australia's southern oceans and compliance with international litter regulations. While fishing-related litter remains the major source of ship-based or ocean litter in Australia's southern oceans, the continued reduction in ship-based litter since 1991 supports increasing compliance to MARPOL (Annex V) by commercial fisheries and shipping in the Great Australian Bight. While Australia participates in marine debris monitoring programs in the Antarctic (under CCAMLR), there is currently no national program or management framework to assess, manage and monitor ocean-based litter along Australia's coasts, and monitor compliance with MARPOL. Apart from the commitments under CCAMLR for Antarctic (and sub-Antarctic) marine environments, there are no other regional programs, guidelines or monitoring protocols or to assess and manage ocean litter in the Southern Ocean.

The application analysis of the multi-angle polarization technique for ocean color remote sensing

NASA Astrophysics Data System (ADS)

Zhang, Yongchao; Zhu, Jun; Yin, Huan; Zhang, Keli

2017-02-01

The multi-angle polarization technique, which uses the intensity of polarized radiation as the observed quantity, is a new remote sensing means for earth observation. With this method, not only can the multi-angle light intensity data be provided, but also the multi-angle information of polarized radiation can be obtained. So, the technique may solve the problems, those could not be solved with the traditional remote sensing methods. Nowadays, the multi-angle polarization technique has become one of the hot topics in the field of the international quantitative research on remote sensing. In this paper, we firstly introduce the principles of the multi-angle polarization technique, then the situations of basic research and engineering applications are particularly summarized and analysed in 1) the peeled-off method of sun glitter based on polarization, 2) the ocean color remote sensing based on polarization, 3) oil spill detection using polarization technique, 4) the ocean aerosol monitoring based on polarization. Finally, based on the previous work, we briefly present the problems and prospects of the multi-angle polarization technique used in China's ocean color remote sensing.

The global distribution and dynamics of chromophoric dissolved organic matter.

PubMed

Nelson, Norman B; Siegel, David A

2013-01-01

Chromophoric dissolved organic matter (CDOM) is a ubiquitous component of the open ocean dissolved matter pool, and is important owing to its influence on the optical properties of the water column, its role in photochemistry and photobiology, and its utility as a tracer of deep ocean biogeochemical processes and circulation. In this review, we discuss the global distribution and dynamics of CDOM in the ocean, concentrating on developments in the past 10 years and restricting our discussion to open ocean and deep ocean (below the main thermocline) environments. CDOM has been demonstrated to exert primary control on ocean color by its absorption of light energy, which matches or exceeds that of phytoplankton pigments in most cases. This has important implications for assessing the ocean biosphere via ocean color-based remote sensing and the evaluation of ocean photochemical and photobiological processes. The general distribution of CDOM in the global ocean is controlled by a balance between production (primarily microbial remineralization of organic matter) and photolysis, with vertical ventilation circulation playing an important role in transporting CDOM to and from intermediate water masses. Significant decadal-scale fluctuations in the abundance of global surface ocean CDOM have been observed using remote sensing, indicating a potentially important role for CDOM in ocean-climate connections through its impact on photochemistry and photobiology.

Primary discussion of a carbon sink in the oceans

NASA Astrophysics Data System (ADS)

Ma, Caihua; You, Kui; Ji, Dechun; Ma, Weiwei; Li, Fengqi

2015-04-01

As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people's living standards. In particular, it is extremely important that the oceans absorb massive amounts of carbon dioxide. This paper takes a pragmatic approach to analyzing the oceans with respect to the causes of discontinuities in oceanic variables of carbon dioxide sinks. We report on an application of chemical, physical and biological methods to analyze the changes of carbon dioxide in oceans. Based on the relationships among the oceans, land, atmosphere and sediment with respect to carbon dioxide, the foundation of carbon dioxide in shell-building and ocean acidification, the changes in carbon dioxide in the oceans and their impact on climate change, and so on, a vital conclusion can be drawn from this study. Specifically, under the condition that the oceans are not disturbed by external forces, the oceans are a large carbon dioxide sink. The result can also be inferred by the formula: C=A-B and G=E+F when the marine ecosystem can keep a natural balance and the amount of carbon dioxide emission is limited within the carrying capacity of the oceans.

Satellite Remote Sensing of Ocean Winds, Surface Waves and Surface Currents during the Hurricanes

NASA Astrophysics Data System (ADS)

Zhang, G.; Perrie, W. A.; Liu, G.; Zhang, L.

2017-12-01

Hurricanes over the ocean have been observed by spaceborne aperture radar (SAR) since the first SAR images were available in 1978. SAR has high spatial resolution (about 1 km), relatively large coverage and capability for observations during almost all-weather, day-and-night conditions. In this study, seven C-band RADARSAT-2 dual-polarized (VV and VH) ScanSAR wide images from the Canadian Space Agency (CSA) Hurricane Watch Program in 2017 are collected over five hurricanes: Harvey, Irma, Maria, Nate, and Ophelia. We retrieve the ocean winds by applying our C-band Cross-Polarization Coupled-Parameters Ocean (C-3PO) wind retrieval model [Zhang et al., 2017, IEEE TGRS] to the SAR images. Ocean waves are estimated by applying a relationship based on the fetch- and duration-limited nature of wave growth inside hurricanes [Hwang et al., 2016; 2017, J. Phys. Ocean.]. We estimate the ocean surface currents using the Doppler Shift extracted from VV-polarized SAR images [Kang et al., 2016, IEEE TGRS]. C-3PO model is based on theoretical analysis of ocean surface waves and SAR microwave backscatter. Based on the retrieved ocean winds, we estimate the hurricane center locations, maxima wind speeds, and radii of the five hurricanes by adopting the SHEW model (Symmetric Hurricane Estimates for Wind) by Zhang et al. [2017, IEEE TGRS]. Thus, we investigate possible relations between hurricane structures and intensities, and especially some possible effects of the asymmetrical characteristics on changes in the hurricane intensities, such as the eyewall replacement cycle. The three SAR images of Ophelia include the north coast of Ireland and east coast of Scotland allowing study of ocean surface currents respond to the hurricane. A system of methods capable of observing marine winds, surface waves, and surface currents from satellites is of value, even if these data are only available in near real-time or from SAR-related satellite images. Insight into high resolution ocean winds, waves and currents in hurricanes can be useful for intensity prediction, which has had relatively few improvements in the past 25 years. In 2018 RADARSAT Constellation Mission will be launched, increasing SAR coverage by 10×, allowing increased observations during the next hurricane season.

Wavemill Product Assessment- Defining Products and Evaluating Potential Performance from a Novel Spaceborne Interferometric SAR

NASA Astrophysics Data System (ADS)

Cotton, P. D.; Gommenginger, C.; Martin, A.; Marquez, J.; Burbidge, G.; Quilfen, Y.; Chapron, B.; Reppucci, A.; Buck, C.

2016-08-01

Ocean Surface Currents are one of the most important ocean properties for oceanographers and operators in the maritime domain. Improved monitoring of ocean currents is systematically the number one requirement that emerges from any science or end user requirement surveys.Wavemill is a novel hybrid interferometric SAR system first proposed by ESA/ESTEC [Buck, 2005]. It offers the possibility of generating two-dimensional wide swath, high resolution, high precision maps of surface current vectors and ocean topography [Buck et al., 2009]. Based on a single spacecraft, it avoids the difficulties of synchronisation and baseline estimation associated with other interferometric SAR systems based on two or more satellites (e.g. the "cartwheel" or "helix" concept).The Wavemill concept has developed steadily since its first inception in 2005. A number of Wavemill studies in recent years have gradually put together facts and figures to support the case for Wavemill as a possible space-borne mission.The Wavemill Product Assessment study (WaPA) aimed to define the scientific capabilities and limitations of a spaceborne Wavemill instrument in preparation for a possible submission of the Wavemill concept as a candidate Earth Explorer Core mission. The WaPA project team brought together expert scientists and engineers in the field of SAR imaging of ocean currents, and included the National Oceanography Centre (UK), Starlab (Spain), IFREMER (France) and Airbus Defence and Space (UK). Overall project management was provided by Satellite Oceanographic Consultants (UK). The approach taken included:- A review of SAR imaging of ocean currents in along-track interferometric mode to learn from previous experiments and modelling what key phenomena need to be accounted for to determine the true performance of a spaceborne Wavemill system- Validation of proposed Wavemill primary products based on Wavemill airborne proof-of-concept data and numerical simulations to determine the capabilities and limitations of a spaceborne Wavemill instrument for ocean current vector and sea surface height mapping.- An analysis of the potential for ocean wind vector retrieval from a spaceborne Wavemill instrument.- An investigation of possible secondary products from Wavemill relating to rivers, ocean/atmosphere interactions, ocean swell and cryospheric applications.An assessment of the synergy between Wavemill and ocean surface current products derived from other remote sensing techniques, accounting for the nature and variability of the measured properties, to identify any additional requirements on a future Wavemill mission.

Amino acid epimerization implies rapid sedimentation rates in Arctic Ocean cores

USGS Publications Warehouse

Sejrup, H.P.; Miller, G.H.; Brigham-Grette, J.; Lovlie, R.; Hopkins, D.

1984-01-01

The palaeooceanography of the Arctic Ocean is less well known than any other ocean basin, due to difficulties in obtaining cores and in providing a secure chronological framework for those cores that have been raised. Most recent investigators have suggested that low sedimentation rates (0.05-0.1 cm kyr-1) have characterized the deep basins over the past 5 Myr (refs 1,2) despite the glacial-marine character of the sediment and proximity to major centres of shelf glaciation. These calculations have been primarily based on the down-core pattern in the inclination of magnetic minerals, supported by uranium-series, 14C and micropalaeontological evidence. Here we analyse amino acid diagnesis in foraminifera from two gravity cores raised from the floor of the Arctic Ocean, our results suggest that these cores span <200 kyr., conflicting with the earlier estimate of 3 Myr based on palaeomagnetic data. The chronology of other Arctic Ocean cores and previous palaeoenvironmental interpretations need re-evaluation. ?? 1984 Nature Publishing Group.

Ocean Chlorophyll as a Precursor of ENSO: An Earth System Modeling Study

NASA Astrophysics Data System (ADS)

Park, Jong-Yeon; Dunne, John P.; Stock, Charles A.

2018-02-01

Ocean chlorophyll concentration, a proxy for phytoplankton, is strongly influenced by internal ocean dynamics such as those associated with El Niño-Southern Oscillation (ENSO). Observations show that ocean chlorophyll responses to ENSO generally lead sea surface temperature (SST) responses in the equatorial Pacific. A long-term global Earth system model simulation incorporating marine biogeochemical processes also exhibits a preceding chlorophyll response. In contrast to simulated SST anomalies, which significantly lag the wind-driven subsurface heat response to ENSO, chlorophyll anomalies respond rapidly. Iron was found to be the key factor connecting the simulated surface chlorophyll anomalies to the subsurface ocean response. Westerly wind bursts decrease central Pacific chlorophyll by reducing iron supply through wind-driven thermocline deepening but increase western Pacific chlorophyll by enhancing the influx of coastal iron from the maritime continent. Our results mechanistically support the potential for chlorophyll-based indices to inform seasonal ENSO forecasts beyond previously identified SST-based indices.

Facets of Arctic energy accumulation based on observations and reanalyses 2000-2015

NASA Astrophysics Data System (ADS)

Mayer, Michael; Haimberger, Leopold; Pietschnig, Marianne; Storto, Andrea

2016-10-01

Various observation- and reanalysis-based estimates of sea ice mass and ocean heat content trends imply that the energy imbalance of the Arctic climate system was similar [1.0 (0.9,1.2) Wm-2] to the global ocean average during the 2000-2015 period. Most of this extra heat warmed the ocean, and a comparatively small fraction went into sea ice melt. Poleward energy transports and radiation contributed to this energy increase at varying strengths. On a seasonal scale, stronger radiative energy input during summer associated with the ice-albedo feedback enhances seasonal oceanic heat uptake and sea ice melt. In return, lower sea ice extent and higher sea surface temperatures lead to enhanced heat release from the ocean during fall. This weakens meridional temperature gradients, consequently reducing atmospheric energy transports into the polar cap. The seasonal cycle of the Arctic energy budget is thus amplified, whereas the Arctic's long-term energy imbalance is close to the global mean.

Amino Acid Stability in the Early Oceans

NASA Technical Reports Server (NTRS)

Parker, E. T.; Brinton, K. L.; Burton, A. S.; Glavin, D. P.; Dworkin, J. P.; Bada, J. L.

2015-01-01

It is likely that a variety of amino acids existed in the early oceans of the Earth at the time of the origin and early evolution of life. "Primordial soup", hydrothermal vent, and meteorite based processes could have contributed to such an inventory. Several "protein" amino acids were likely present, however, based on prebiotic synthesis experiments and carbonaceous meteorite studies, non-protein amino acids, which are rare on Earth today, were likely the most abundant. An important uncertainty is the length of time these amino acids could have persisted before their destruction by abiotic and biotic processes. Prior to life, amino acid concentrations in the oceans were likely regulated by circulation through hydro-thermal vents. Today, the entire ocean circulates through vent systems every 10(exp 7) years. On the early Earth, this value was likely smaller due to higher heat flow and thus marine amino acid life-time would have been shorter. After life, amino acids in the oceans could have been assimilated by primitive organisms.

Facets of Arctic energy accumulation based on observations and reanalyses 2000-2015.

PubMed

Mayer, Michael; Haimberger, Leopold; Pietschnig, Marianne; Storto, Andrea

2016-10-16

Various observation- and reanalysis-based estimates of sea ice mass and ocean heat content trends imply that the energy imbalance of the Arctic climate system was similar [1.0 (0.9,1.2) Wm -2 ] to the global ocean average during the 2000-2015 period. Most of this extra heat warmed the ocean, and a comparatively small fraction went into sea ice melt. Poleward energy transports and radiation contributed to this energy increase at varying strengths. On a seasonal scale, stronger radiative energy input during summer associated with the ice-albedo feedback enhances seasonal oceanic heat uptake and sea ice melt. In return, lower sea ice extent and higher sea surface temperatures lead to enhanced heat release from the ocean during fall. This weakens meridional temperature gradients, consequently reducing atmospheric energy transports into the polar cap. The seasonal cycle of the Arctic energy budget is thus amplified, whereas the Arctic's long-term energy imbalance is close to the global mean.

NEOTEC: Negative-CO2-Emissions Marine Energy With Direct Mitigation of Global Warming, Sea-Level Rise and Ocean Acidification

NASA Astrophysics Data System (ADS)

Rau, G. H.; Baird, J.; Noland, G.

2016-12-01

The vertical thermal energy potential in the ocean is a massive renewable energy resource that is growing due to anthropogenic warming of the surface and near-surface ocean. The conversion of this thermal energy to useful forms via Ocean Thermal Energy Conversion (OTEC) has been demonstrated over the past century, albeit at small scales. Because OTEC removes heat from the surface ocean, this could help directly counter ongoing, deleterious ocean/atmosphere warming. The only other climate intervention that could do this is solar radiation "geoengineering". Conventional OTEC requires energy intensive, vertical movement of seawater resulting in ocean and atmospheric chemistry alteration, but this can be avoided via more energy efficient, vertical closed-cycle heating and cooling of working fluid like CO2 or NH3. An energy carrier such as H2 is required to transport energy optimally extracted far offshore, and methods of electrochemically generating H2 while also consuming CO2 and converting it to ocean alkalinity have been demonstrated. The addition of such alkalinity to the ocean would provide vast, stable, carbon storage, while also helping chemically counter the effects of ocean acidification. The process might currently be profitable given the >$100/tonne CO2 credit offered by California's Low Carbon Fuel Standard for transportation fuels like H2. Negative-Emissions OTEC, NEOTEC, thus can potentially provide constant, cost effective, high capacity, negative-emissions energy while: a) reducing surface ocean heat load, b) reducing thermal ocean expansion and sea-level rise, c) utilizing a very large, natural marine carbon storage reservoir, and d) helping mitigate ocean acidification. The technology also avoids the biophysical and land use limitations posed by negative emissions methods that rely on terrestrial biology, such as afforestation and BECCS. NEOTEC and other marine-based, renewable energy and CO2 removal approaches could therefore greatly increase the likelihood of satisfying growing global energy demand while helping to stabilize or reduce atmospheric CO2 and its impacts. Policies supporting the search and evaluation of renewable energy and negative emissions options beyond biotic- and land-based methods are needed.

A Strategy to Learn How to Build Scientific-Education and Outreach Partnerships in the Ocean Sciences: COSEE Ocean Learning Communities.

NASA Astrophysics Data System (ADS)

Keil, R. G.; Bell, P. L.; Bittner, M. S.; Robigou, V.; Sider, K.

2005-12-01

The College of Ocean and Fishery Sciences and the College of Education at the University of Washington, the Seattle Aquarium, and the California Maritime Academy formed a partnership to establish a Center for Ocean Sciences Education Excellence (COSEE) labeled "Ocean Learning Communities." The COSEE-OLC will join the national network of NSF-funded centers that provide a catalytic environment in which partnerships between ocean researchers and educators flourish. The COSEE network contributes to the national advancement of ocean science education by sharing high-quality K-12 or informal education programs, best practices and methodologies, and offering exemplary courses through the network and at national professional meetings. Building on the successes and lessons of the existing COSEE centers, the COSEE-OLC will foster collaborations among the oceanography research community, the science of learning community, informal and formal educators, the general public, and the maritime industry in the Northwest region and the West coast. The concept for this partnership is based on reaching out to traditionally underserved populations (from the businesses that use the sea or for which economic success depends on the oceans to the united native tribes), listening to their concerns and needs and how these can be addressed within the context of ocean-based research. The challenges of integrating education and outreach with scientific research programs are addressed by the center's main catalytic activity to create Ocean Learning Communities. These communities will be gatherings of traditionally disparate stakeholders including scientists, educators, representatives of businesses with a connection to the oceans, and citizens who derive economic or recreational sustenance from the oceans. The center's principal goal is to, through time and structured learning activities, support various communities 1) to develop a common language and 2) to make a commitment to creating collaborations that will improve ocean research and public awareness at the regional scale. Researchers in the science of learning will evaluate and study the successes and challenges of these regional approaches to better understand the development and sustainability of productive partnerships and to develop learning models to share and apply at the national level.

Hybrid-type endoscopic thyroidectomy (HET: Tori's method) for differentiated thyroid carcinoma including invasion to the trachea.

PubMed

Tori, Masayuki

2014-03-01

Endoscopic thyroidectomy (ET) or robotic thyroidectomy is yet to be applied to thyroid carcinoma invasive to the trachea and to wide lymph node node metastasis. On the other hand, small-incision thyroidectomy lacks sufficient working space and clear vision. The author has newly developed hybrid-type endoscopic thyroidectomy (HET) to overcome these problems. From March 2011 to February 2012, HET was performed for 85 patients. Clinicopathologic characteristics were analyzed. To evaluate the superiority of HET for malignancy representatively, conventional lobectomy with central compartment node dissection (CCND) performed 1 year previously was compared with HET. In lobectomy and node dissection, a single skin incision (1.5 cm) is made above the clavicle, with a port incision (5 mm) made 3 cm below the clavicle. Then CCND is performed directly through the incision by lifting up the isthmus. To obtain sufficient working space for the lobectomy, the strap muscles are taped and pulled toward the head, then hung by the cradle. The thyroid lobe is retracted to the midline with a retractor, followed by isolation of the inferior laryngeal nerve and transection of the inferior thyroid vessels with the monitor of the scope. Lateral lymph nodes dissection can be performed at the same time, if necessary. In total thyroidectomy, the same procedure is performed at the opposite side. The scalpel can be used to shave through each incision in case of tracheal invasion. Of the 85 cases, 62 were malignant, involving papillary thyroid carcinoma (PTC), and 23 were benign. Total thyroidectomy was performed for 22 of the PTC cases and CCND for 49 of the cases. Shaving for tracheal invasion was performed for eight patients. No mortality, complications, recurrence, or metastasis was found 1-2 years after the operation. Compared with conventional thyroidectomy, HET was superior in blood loss, visual analog scale, and postoperative hospital stay. The author's method (Tori's method) might be less invasive, cosmetically excellent, and moreover, safe and feasible for differentiated thyroid carcinoma including invasion to the trachea.

Global phylogeography of the scalloped hammerhead shark (Sphyrna lewini).

PubMed

Duncan, K M; Martin, A P; Bowen, B W; DE Couet, H G

2006-07-01

Large marine fishes typically have little population genetic structure. The exceptions are associated with sedentary behaviour, disjunct distributions, or reproductive philopatry. Scalloped hammerhead sharks (Sphyrna lewini) incorporate the contrasting traits of oceanic habitat (usually associated with high dispersal) and possible fidelity to nursery grounds (for reproductive females). To evaluate the expectations of these contrasting behaviours, we examined the global genetic structure of S. lewini based on collections (n = 271 individuals) from 20 nursery areas. A 548-bp fragment of mitochondrial DNA control region revealed 22 polymorphic sites, 24 haplotypes, and three lineages distinguished by 2.56-3.77% sequence divergence. Coalescence analyses based on a provisional molecular clock indicate an origin in the Indo-West Pacific with late Pleistocene radiations into the central Pacific (Hawaii) and eastern Pacific (Central America), as well as recent interchange between oceans via southern Africa. Population subdivisions are strong (overall Phi(ST) = 0.749, P < 0.0001 and among oceans Phi(ST) = 0.598, P < 0.0098). Genetic discontinuity within oceans (Phi(ST) = 0.519, P < 0.0001) is primarily associated with oceanic barriers (migration across oceans M approximately 0), with much less structure along continental margins (M > 10). We conclude that nursery populations linked by continuous coastline have high connectivity, but that oceanic dispersal by females is rare. Although we cannot rule out philopatry to natal nurseries, oceanic barriers appear to have a much stronger influence on the genetic architecture of this species and may indicate a mechanism for recent evolutionary radiations in the genus Sphyrna.

Impact of ocean acidification on the hypoxia tolerance of the woolly sculpin, Clinocottus analis.

PubMed

Hancock, Joshua R; Place, Sean P

2016-01-01

As we move into the Anthropocene, organisms inhabiting marine environments will continue to face growing challenges associated with changes in ocean pH (ocean acidification), dissolved oxygen (dead zones) and temperature. These factors, in combination with naturally variable environments such as the rocky intertidal zone, may create extreme physiological challenges for organisms that are already performing near their biological limits. Although numerous studies have examined the impacts of climate-related stressors on intertidal animals, little is known about the underlying physiological mechanisms driving adaptation to ocean acidification and how this may alter organism interactions, particularly in marine vertebrates. Therefore, we have investigated the effects of decreased ocean pH on the hypoxia response of an intertidal sculpin, Clinocottus analis . We used both whole-animal and biochemistry-based analyses to examine how the energetic demands associated with acclimation to low-pH environments may impact the fish's reliance on facultative air breathing in low-oxygen environments. Our study demonstrated that acclimation to ocean acidification resulted in elevated routine metabolic rates and acid-base regulatory capacity (Na + ,K + -ATPase activity). These, in turn, had downstream effects that resulted in decreased hypoxia tolerance (i.e. elevated critical oxygen tension). Furthermore, we present evidence that these fish may be living near their physiological capacity when challenged by ocean acidification. This serves as a reminder that the susceptibility of teleost fish to changes in ocean pH may be underestimated, particularly when considering the multiple stressors that many experience in their natural environments.

Ocean Tracks: Investigating Marine Migrations in a Changing Ocean

NASA Astrophysics Data System (ADS)

Krumhansl, R.; Kochevar, R. E.; Aluwihare, L.; Bardar, E. W.; Hirsch, L.; Hoyle, C.; Krumhansl, K.; Louie, J.; Madura, J.; Mueller-Northcott, J.; Peach, C. L.; Trujillo, A.; Winney, B.; Zetterlind, V.; Busey, A.

2015-12-01

The availability of scientific data sets online opens up exciting new opportunities to raise students' understanding of the worlds' oceans and the potential impacts of climate change. The Oceans of Data Institute at EDC; Stanford University; and the Scripps Institution of Oceanography have been collaborating, with the support of three National Science Foundation grants over the past 5 years, to bring marine science data sets into high school and undergraduate classrooms. These efforts have culminated in the development of a web-based student interface to data from the Tagging of Pacific Predators (TOPP) program, NOAA's Global Drifter Program, and NASA Earth-orbiting satellites through a student-friendly Web interface, customized data analysis tools, multimedia supports, and course modules. Ocean Tracks (http://oceantracks.org), which incorporates design principles based on a broad range of research findings in fields such as cognitive science, visual design, mathematics education and learning science, focuses on optimizing students' opportunities to focus their cognitive resources on viewing and comparing data to test hypotheses, while minimizing the time spent on downloading, filtering and creating displays. Ocean Tracks allows students to display the tracks of elephant seals, white sharks, Bluefin tuna, albatross, and drifting buoys along with sea surface temperature, chlorophyll-A, bathymetry, ocean currents, and human impacts overlays. A graphing tool allows students to dynamically display parameters associated with the track such as speed, deepest daily dive and track tortuosity (curviness). These interface features allow students to engage in investigations that mirror those currently being conducted by scientists to understand the broad-scale effects of changes in climate and other human activities on ocean ecosystems. In addition to supporting the teaching of the Ocean and Climate Literacy principles, high school curriculum modules facilitate the teaching of content, practices and cross-cutting concepts in the Framework for K-12 Science Education. Undergraduate modules currently under development support the teaching of content related to marine productivity, ocean circulation and upwelling, animal-environment interactions, ocean ecosystems, and human impacts.

MeltMigrator: A MATLAB-based software for modeling three-dimensional melt migration and crustal thickness variations at mid-ocean ridges following a rules-based approach

NASA Astrophysics Data System (ADS)

Bai, Hailong; Montési, Laurent G. J.; Behn, Mark D.

2017-01-01

MeltMigrator is a MATLAB®-based melt migration software developed to process three-dimensional mantle temperature and velocity data from user-supplied numerical models of mid-ocean ridges, calculate melt production and melt migration trajectories in the mantle, estimate melt flux along plate boundaries, and predict crustal thickness distribution on the seafloor. MeltMigrator is also capable of calculating compositional evolution depending on the choice of petrologic melting model. Programmed in modules, MeltMigrator is highly customizable and can be expanded to a wide range of applications. We have applied it to complex mid-ocean ridge model settings, including transform faults, oblique segments, ridge migration, asymmetrical spreading, background mantle flow, and ridge-plume interaction. In this technical report, we include an example application to a segmented mid-ocean ridge. MeltMigrator is available as a supplement to this paper, and it is also available from GitHub and the University of Maryland Geodynamics Group website.

Reconciling estimates of the ratio of heat and salt fluxes at the ice-ocean interface

NASA Astrophysics Data System (ADS)

Keitzl, T.; Mellado, J. P.; Notz, D.

2016-12-01

The heat exchange between floating ice and the underlying ocean is determined by the interplay of diffusive fluxes directly at the ice-ocean interface and turbulent fluxes away from it. In this study, we examine this interplay through direct numerical simulations of free convection. Our results show that an estimation of the interface flux ratio based on direct measurements of the turbulent fluxes can be difficult because the flux ratio varies with depth. As an alternative, we present a consistent evaluation of the flux ratio based on the total heat and salt fluxes across the boundary layer. This approach allows us to reconcile previous estimates of the ice-ocean interface conditions. We find that the ratio of heat and salt fluxes directly at the interface is 83-100 rather than 33 as determined by previous turbulence measurements in the outer layer. This can cause errors in the estimated ice-ablation rate from field measurements of up to 40% if they are based on the three-equation formulation.

3 CFR 8392 - Proclamation 8392 of June 12, 2009. National Oceans Month, 2009

Code of Federal Regulations, 2010 CFR

2010-01-01

... and affect our lives in a variety of ways. This month we celebrate the wonder of the oceans, and we... supporting life. From the abyssal plains of the Pacific to the shallow coral reefs and seagrass beds of the Florida Keys, oceans support an incredible diversity of marine life and ecosystems. The base of the...

77 FR 2513 - Draft Environmental Impact Statement for Effects of Oil and Gas Activities in the Arctic Ocean

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-18

... Environmental Impact Statement for Effects of Oil and Gas Activities in the Arctic Ocean AGENCY: National Marine... Environmental Impact Statement (DEIS) for the Effects of Oil and Gas Activities in the Arctic Ocean.'' Based on... Web page at: http://www.nmfs.noaa.gov/pr/permits/eis/arctic.htm . FOR FURTHER INFORMATION CONTACT...

A Multilayer Dataset of SSM/I-Derived Global Ocean Surface Turbulent Fluxes

NASA Technical Reports Server (NTRS)

Chou, Shu-Hsien; Shie, Chung-Lin; Atlas, Robert M.; Ardizzone, Joe; Nelkin, Eric; Einaud, Franco (Technical Monitor)

2001-01-01

A dataset including daily- and monthly-mean turbulent fluxes (momentum, latent heat, and sensible heat) and some relevant parameters over global oceans, derived from the Special Sensor Microwave/Imager (SSM/I) data, for the period July 1987-December 1994 and the 1988-94 annual and monthly-mean climatologies of the same variables is created. It has a spatial resolution of 2.0deg x 2.5deg latitude-longitude. The retrieved surface air humidity is found to be generally accurate as compared to the collocated radiosonde observations over global oceans. The retrieved wind stress and latent heat flux show useful accuracy as verified against research quality measurements of ship and buoy in the western equatorial Pacific. The 1988-94 seasonal-mean wind stress and latent heat flux show reasonable patterns related to seasonal variations of the atmospheric general circulation. The patterns of 1990-93 annual-mean turbulent fluxes and input variables are generally in good agreement with one of the best global analyzed flux datasets that based on COADS (comprehensive ocean-atmosphere data set) with corrections on wind speeds and covered the same period. The retrieved wind speed is generally within +/-1 m/s of the COADS-based, but is stronger by approx. 1-2 m/s in the northern extratropical oceans. The discrepancy is suggested to be mainly due to higher COADS-modified wind speeds resulting from underestimation of anemometer heights. Compared to the COADS-based, the retrieved latent heat flux and sea-air humidity difference are generally larger with significant differences in the trade wind zones and the ocean south of 40degS (up to approx. 40-60 W/sq m and approx. 1-1.5 g/kg). The discrepancy is believed to be mainly caused by higher COADS-based surface air humidity arising from the overestimation of dew point temperatures and from the extrapolation of observed high humidity southward into data-void regions south of 40degS. The retrieved sensible heat flux is generally within +/-5 W/sq m of UWM/COADS, except for some areas in the extratropical oceans, where the differences in wind speed have large impact on the difference in sensible heat flux. The dataset of SSM/I-derived turbulent fluxes is useful for climate studies, forcing of ocean models, and validation of coupled ocean-atmosphere global models.

OCEAN: Optimized Cross rEActivity estimatioN.

PubMed

Czodrowski, Paul; Bolick, Wolf-Guido

2016-10-24

The prediction of molecular targets is highly beneficial during the drug discovery process, be it for off-target elucidation or deconvolution of phenotypic screens. Here, we present OCEAN, a target prediction tool exclusively utilizing publically available ChEMBL data. OCEAN uses a heuristics approach based on a validation set containing almost 1000 drug ← → target relationships. New ChEMBL data (ChEMBL20 as well as ChEMBL21) released after the validation was used for a prospective OCEAN performance check. The success rates of OCEAN to predict correctly the targets within the TOP10 ranks are 77% for recently marketed drugs and 62% for all new ChEMBL20 compounds and 51% for all new ChEMBL21 compounds. OCEAN is also capable of identifying polypharmacological compounds; the success rate for molecules simultaneously hitting at least two targets is 64% to be correctly predicted within the TOP10 ranks. The source code of OCEAN can be found at http://www.github.com/rdkit/OCEAN.

Sea level change since 2005: importance of salinity

NASA Astrophysics Data System (ADS)

Llovel, W.; Purkey, S.; Meyssignac, B.; Kolodziejczyk, N.; Blazquez, A.; Bamber, J. L.

2017-12-01

Sea level rise is one of the most important consequences of the actual global warming. Global mean sea level has been rising at a faster rate since 1993 (over the satellite altimetry era) than previous decades. This rise is expected to accelerate over the coming decades and century. At global scale, sea level rise is caused by a combination of freshwater increase from land ice melting and land water changes (mass component) and ocean warming (thermal expansion). Estimating the causes is of great interest not only to understand the past sea level changes but also to validate projections based on climate models. In this study, we investigate the global mass contribution to recent sea level changes with an alternative approach by estimating the global ocean freshening. For that purpose, we consider the unprecedented amount of salinity measurements from Argo floats for the past decade (2005-2015). We compare our results to the ocean mass inferred by GRACE data and based on a sea level budget approach. Our results bring new constrains on the global water cycle (ocean freshening) and energy budget (ocean warming) as well as on the global ocean mass directly inferred from GRACE data.

Diagnosis of CO2 Fluxes in the Coastal Ocean

NASA Astrophysics Data System (ADS)

Dai, M.; Cao, Z.; Yang, W.; Guo, X.; Yin, Z.; Zhao, Y.

2017-12-01

Coastal ocean carbon is an important component of the global carbon cycle. However, its mechanistic-based conceptualization, a prerequisite of coastal carbon modeling and its inclusion in the Earth System Model, remains difficult due to the highest variability in both time and space. Here we show that the inter-seasonal change of the global coastal pCO2 is more determined by non-temperature factors such as biological drawdown and water mass mixing, the latter of which features the dynamic boundary processes of the coastal ocean at both land-margin and margin-open ocean interfaces. Considering these unique features, we resolve the coastal CO2 fluxes using a semi-analytical approach coupling physics-biogeochemistry and carbon-nutrients and conceptualize the coastal carbon cycle into Ocean-dominated Margins (OceMar) and River-dominated Ocean Margins (RiOMar). The diagnostic result of CO2 fluxes in the South China Sea basin and the Arabian Sea as OceMars and in the Pearl River Plume as a RioMar is consistent with field observations. Our mechanistic-based diagnostic approach therefore helps better understand and model coastal carbon cycle yet the stoichiometry of carbon-nutrients coupling needs scrutiny when applying our approach.

A global reference model of Curie-point depths based on EMAG2

PubMed Central

Li, Chun-Feng; Lu, Yu; Wang, Jian

2017-01-01

In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C)−1 for the ocean and K = ~2.5 W(m°C)−1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m2, leading to a global heat loss ranging from ~34.6 to 36.6 TW. PMID:28322332

A new simple concept for ocean colour remote sensing using parallel polarisation radiance

PubMed Central

He, Xianqiang; Pan, Delu; Bai, Yan; Wang, Difeng; Hao, Zengzhou

2014-01-01

Ocean colour remote sensing has supported research on subjects ranging from marine ecosystems to climate change for almost 35 years. However, as the framework for ocean colour remote sensing is based on the radiation intensity at the top-of-atmosphere (TOA), the polarisation of the radiation, which contains additional information on atmospheric and water optical properties, has largely been neglected. In this study, we propose a new simple concept to ocean colour remote sensing that uses parallel polarisation radiance (PPR) instead of the traditional radiation intensity. We use vector radiative transfer simulation and polarimetric satellite sensing data to demonstrate that using PPR has two significant advantages in that it effectively diminishes the sun glint contamination and enhances the ocean colour signal at the TOA. This concept may open new doors for ocean colour remote sensing. We suggest that the next generation of ocean colour sensors should measure PPR to enhance observational capability. PMID:24434904

The growth of finfish in global open-ocean aquaculture under climate change.

PubMed

Klinger, Dane H; Levin, Simon A; Watson, James R

2017-10-11

Aquaculture production is projected to expand from land-based operations to the open ocean as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-ocean aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the oceans. We employ a novel spatial model to estimate the potential of open-ocean finfish aquaculture globally, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different thermal guilds-Atlantic salmon ( Salmo salar ), gilthead seabream ( Sparus aurata ) and cobia ( Rachycentron canadum )-is compared across species and regions and with climate change, based on outputs of a high-resolution global climate model. Globally, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses. © 2017 The Author(s).

Ocean Hydrodynamics Numerical Model in Curvilinear Coordinates for Simulating Circulation of the Global Ocean and its Separate Basins.

NASA Astrophysics Data System (ADS)

Gusev, Anatoly; Diansky, Nikolay; Zalesny, Vladimir

2010-05-01

The original program complex is proposed for the ocean circulation sigma-model, developed in the Institute of Numerical Mathematics (INM), Russian Academy of Sciences (RAS). The complex can be used in various curvilinear orthogonal coordinate systems. In addition to ocean circulation model, the complex contains a sea ice dynamics and thermodynamics model, as well as the original system of the atmospheric forcing implementation on the basis of both prescribed meteodata and atmospheric model results. This complex can be used as the oceanic block of Earth climate model as well as for solving the scientific and practical problems concerning the World ocean and its separate oceans and seas. The developed program complex can be effectively used on parallel shared memory computational systems and on contemporary personal computers. On the base of the complex proposed the ocean general circulation model (OGCM) was developed. The model is realized in the curvilinear orthogonal coordinate system obtained by the conformal transformation of the standard geographical grid that allowed us to locate the system singularities outside the integration domain. The horizontal resolution of the OGCM is 1 degree on longitude, 0.5 degree on latitude, and it has 40 non-uniform sigma-levels in depth. The model was integrated for 100 years starting from the Levitus January climatology using the realistic atmospheric annual cycle calculated on the base of CORE datasets. The experimental results showed us that the model adequately reproduces the basic characteristics of large-scale World Ocean dynamics, that is in good agreement with both observational data and results of the best climatic OGCMs. This OGCM is used as the oceanic component of the new version of climatic system model (CSM) developed in INM RAS. The latter is now ready for carrying out the new numerical experiments on climate and its change modelling according to IPCC (Intergovernmental Panel on Climate Change) scenarios in the scope of the CMIP-5 (Coupled Model Intercomparison Project). On the base of the complex proposed the Pacific Ocean circulation eddy-resolving model was realized. The integration domain covers the Pacific from Equator to Bering Strait. The model horizontal resolution is 0.125 degree and it has 20 non-uniform sigma-levels in depth. The model adequately reproduces circulation large-scale structure and its variability: Kuroshio meandering, ocean synoptic eddies, frontal zones, etc. Kuroshio high variability is shown. The distribution of contaminant was simulated that is admittedly wasted near Petropavlovsk-Kamchatsky. The results demonstrate contaminant distribution structure and provide us understanding of hydrological fields formation processes in the North-West Pacific.

Suzaku  Observations of Heavily Obscured (Compton-thick) Active Galactic Nuclei Selected by the Swift/BAT Hard X-Ray Survey

NASA Astrophysics Data System (ADS)

Tanimoto, Atsushi; Ueda, Yoshihiro; Kawamuro, Taiki; Ricci, Claudio; Awaki, Hisamitsu; Terashima, Yuichi

2018-02-01

We present a uniform broadband X-ray (0.5–100.0 keV) spectral analysis of 12 Swift/Burst Alert Telescope selected Compton-thick ({log}{N}{{H}}/{{cm}}-2≥slant 24) active galactic nuclei (CTAGNs) observed with Suzaku. The Suzaku data of three objects are published here for the first time. We fit the Suzaku and Swift spectra with models utilizing an analytic reflection code and those utilizing the Monte-Carlo-based model from an AGN torus by Ikeda et al. The main results are as follows: (1) The estimated intrinsic luminosity of a CTAGN strongly depends on the model; applying Compton scattering to the transmitted component in an analytic model may largely overestimate the intrinsic luminosity at large column densities. (2) Unabsorbed reflection components are commonly observed, suggesting that the tori are clumpy. (3) Most of CTAGNs show small scattering fractions (<0.5%), implying a buried AGN nature. (4) Comparison with the results obtained for Compton-thin AGNs suggests that the properties of these CTAGNs can be understood as a smooth extension from Compton-thin AGNs with heavier obscuration; we find no evidence that the bulk of the population of hard-X-ray-selected CTAGNs are different from less obscured objects.

One-dimensional MHD simulations of MTF systems with compact toroid targets and spherical liners

NASA Astrophysics Data System (ADS)

Khalzov, Ivan; Zindler, Ryan; Barsky, Sandra; Delage, Michael; Laberge, Michel

2017-10-01

One-dimensional (1D) MHD code is developed in General Fusion (GF) for coupled plasma-liner simulations in magnetized target fusion (MTF) systems. The main goal of these simulations is to search for optimal parameters of MTF reactor, in which spherical liquid metal liner compresses compact toroid plasma. The code uses Lagrangian description for both liner and plasma. The liner is represented as a set of spherical shells with fixed masses while plasma is discretized as a set of nested tori with circular cross sections and fixed number of particles between them. All physical fields are 1D functions of either spherical (liner) or small toroidal (plasma) radius. Motion of liner and plasma shells is calculated self-consistently based on applied forces and equations of state. Magnetic field is determined by 1D profiles of poloidal and toroidal fluxes - they are advected with shells and diffuse according to local resistivity, this also accounts for flux leakage into the liner. Different plasma transport models are implemented, this allows for comparison with ongoing GF experiments. Fusion power calculation is included into the code. We performed a series of parameter scans in order to establish the underlying dependencies of the MTF system and find the optimal reactor design point.

Atmospheric Blocking and Atlantic Multi-Decadal Ocean Variability

NASA Technical Reports Server (NTRS)

Haekkinen, Sirpa; Rhines, Peter B.; Worthlen, Denise L.

2011-01-01

Based on the 20th century atmospheric reanalysis, winters with more frequent blocking, in a band of blocked latitudes from Greenland to Western Europe, are found to persist over several decades and correspond to a warm North Atlantic Ocean, in-phase with Atlantic multi-decadal ocean variability. Atmospheric blocking over the northern North Atlantic, which involves isolation of large regions of air from the westerly circulation for 5 days or more, influences fundamentally the ocean circulation and upper ocean properties by impacting wind patterns. Winters with clusters of more frequent blocking between Greenland and western Europe correspond to a warmer, more saline subpolar ocean. The correspondence between blocked westerly winds and warm ocean holds in recent decadal episodes (especially, 1996-2010). It also describes much longer-timescale Atlantic multidecadal ocean variability (AMV), including the extreme, pre-greenhouse-gas, northern warming of the 1930s-1960s. The space-time structure of the wind forcing associated with a blocked regime leads to weaker ocean gyres and weaker heat-exchange, both of which contribute to the warm phase of AMV.

Mechanisms of the global electric circuit and lightning variability on the ENSO time scale

NASA Astrophysics Data System (ADS)

Mareev, Evgeny; Volodin, Evgeny; Slyunyaev, Nikolay

2017-04-01

Many studies of lightning activity on the El Niño-Southern Oscillation (ENSO) time scale show increased activity over tropical land areas during the warm El Niño phase (e.g., Satori et al., 2009; Price, 2009). The mechanisms of this variability—particularly in terms of its role in the global electric circuit (GEC)—are still under debate (e.g., Williams and Mareev, 2014). In this study a general circulation model of the atmosphere and ocean INMCM4.0 (Institute of Numerical Mathematics Coupled Model) is used for modelling the GEC variability on the ENSO time scale. The ionospheric potential (IP) and the lightning flash rate are calculated to study regional peculiarities and possible mechanisms of lightning variation. The IP parameterisation is used (Mareev and Volodin, 2014) which takes into account quasi-stationary currents of electrified clouds (including thunderstorms) as principal contributors into the DC global circuit. The account of conductivity variation in the IP parameterisation is suggested based on the approach realised in (Slyunyaev et al., 2014). Comparison of simulation results with the observational data on lightning activity on the ENSO time scale is discussed. Numerical simulations suggest that the inter-annual IP variability is low and does not exceed 1% of the mean value, being tightly correlated with the mean sea surface temperature (SST) in the Pacific Ocean (180W-100W, 5S-5N—El Niño area). The IP maximum corresponds to the SST minimum. This result can be explained taking into account that during El Niño (positive temperature anomaly) precipitations in the equatorial part of the Pacific increase while in other tropic zones including the land areas they decrease. Comparison of simulation results with the observational data on lightning activity on the ENSO time scale is discussed. During the El Niño period in the model, the mean aerosol content in the atmosphere decrease, which is caused by the weakening of the winds over Sahara and South-West Asia lifting dust into the atmosphere. Taking into consideration the decrease in the number of thunderstorms, this does not explain the observed global lightning variation. As another possible explanation for the enhanced El Niño lightning activity, the variation of the atmospheric aerosols and cloud condensation nuclei due to fires is discussed. The work was supported by a grant from the Government of the Russian Federation (contract no. 14.B25.31.0023) and by RFBR grant no. 16-05-01086. References Mareev E.A., Volodin E.M. (2014), Variation of the global electric circuit and ionospheric potential in a general circulation model, Geophys. Res. Lett., V. 41, P. 9009-9016. Sátori G., Williams E., Lemperger I. (2009), Variability of global lightning activity on the ENSO time scale, Atmos. Res., V. 91, P. 500-507. Price C. (2009), Will a drier climate result in a more lightning?, Atmos. Res., V. 91, P. 479-484. Williams E.R., Mareev E.A. (2014), Recent progress on the global electrical circuit, Atmos. Res., V. 135-136, P. 208-227. Slyunyaev N.N., Mareev E.A., Kalinin A.V., Zhidkov A.A. (2014), Influence of large-scale conductivity inhomogeneities in the atmosphere on the global electric circuit, J. Atmos. Sci., V. 71, P. 4382-4396.

Remote assessment of ocean color for interpretation of satellite visible imagery: A review

NASA Technical Reports Server (NTRS)

Gordon, H. R.; Morel, A. Y.

1983-01-01

An assessment is presented of the state-of-the-art of remote, (satellite-based) Coastal Zone Color (CZCS) Scanning of color variations in the ocean due to phytoplankton. Attention is given to physical problems associated with ocean color remote sensing, in-water algorithms for the correction of atmospheric effects, constituent retrieval algorithms and application of the algorithms to CZCS imagery. The applicability of CZCS to both near-coast and mid-ocean waters is considered, and it is concluded that while differences between the two environments are complex, universal algorithms can be used for the case of mid-ocean waters, and site-specific algorithms are adequate for CZCS imaging of the near-coast oceanic environment. A short description of CVCS and some sample photographs are provided in an appendix.

Fiber-coupling efficiency of Gaussian-Schell model beams through an ocean to fiber optical communication link

NASA Astrophysics Data System (ADS)

Hu, Beibei; Shi, Haifeng; Zhang, Yixin

2018-06-01

We theoretically study the fiber-coupling efficiency of Gaussian-Schell model beams propagating through oceanic turbulence. The expression of the fiber-coupling efficiency is derived based on the spatial power spectrum of oceanic turbulence and the cross-spectral density function. Our work shows that the salinity fluctuation has a greater impact on the fiber-coupling efficiency than temperature fluctuation does. We can select longer λ in the "ocean window" and higher spatial coherence of light source to improve the fiber-coupling efficiency of the communication link. We also can achieve the maximum fiber-coupling efficiency by choosing design parameter according specific oceanic turbulence condition. Our results are able to help the design of optical communication link for oceanic turbulence to fiber sensor.

Characteristic Sizes of Life in the Oceans, from Bacteria to Whales.

PubMed

Andersen, K H; Berge, T; Gonçalves, R J; Hartvig, M; Heuschele, J; Hylander, S; Jacobsen, N S; Lindemann, C; Martens, E A; Neuheimer, A B; Olsson, K; Palacz, A; Prowe, A E F; Sainmont, J; Traving, S J; Visser, A W; Wadhwa, N; Kiørboe, T

2016-01-01

The size of an individual organism is a key trait to characterize its physiology and feeding ecology. Size-based scaling laws may have a limited size range of validity or undergo a transition from one scaling exponent to another at some characteristic size. We collate and review data on size-based scaling laws for resource acquisition, mobility, sensory range, and progeny size for all pelagic marine life, from bacteria to whales. Further, we review and develop simple theoretical arguments for observed scaling laws and the characteristic sizes of a change or breakdown of power laws. We divide life in the ocean into seven major realms based on trophic strategy, physiology, and life history strategy. Such a categorization represents a move away from a taxonomically oriented description toward a trait-based description of life in the oceans. Finally, we discuss life forms that transgress the simple size-based rules and identify unanswered questions.

Oceanic Transport

NASA Technical Reports Server (NTRS)

Chase, R.; Mcgoldrick, L.

1984-01-01

The importance of large-scale ocean movements to the moderation of Global Temperature is discussed. The observational requirements of physical oceanography are discussed. Satellite-based oceanographic observing systems are seen as central to oceanography in 1990's.

Trends in Marine Debris along the U.S. Pacific Coast and Hawai’i 1998-2007

USGS Publications Warehouse

Ribic, Christine; Seba B. Sheavly,; Rugg, David J.; Erdmann, Eric S.

2012-01-01

We assessed amounts, composition, and trends of marine debris for the U.S. Pacific Coast and Hawai’i using National Marine Debris Monitoring Program data. Hawai’i had the highest debris loads; the North Pacific Coast region had the lowest debris loads. The Southern California Bight region had the highest land-based debris loads. Debris loads decreased over time for all source categories in all regions except for land-based and general-source loads in the North Pacific Coast region, which were unchanged. General-source debris comprised 30–40% of the items in all regions. Larger local populations were associated with higher land-based debris loads across regions; the effect declined at higher population levels. Upwelling affected deposition of ocean-based and general-source debris loads but not land-based loads along the Pacific Coast. LNSO decreased debris loads for both land-based and ocean-based debris but not general-source debris in Hawai’i, a more complex climate-ocean effect than had previously been found.

Acoustic Tomographic Estimate of Ocean Advective Heat Flux: A Numerical Assessment in the Norwegian Sea

DTIC Science & Technology

1990-06-01

of transceivers used and the characteristics of the sound channel. In the assessment we use the General Digital Environmental Model ( GDEM ), a...sound channel. In the assessment we use the General Digital Environmental Model ( GDEM ), a climatological data base, to simulate an ocean area 550 x 550...34 3. GDEM Data Base