WorldWideScience

Sample records for simulated marine stratocumulus

  1. Microphysical structure of simulated marine stratocumulus: Effects of physical and numerical approximations

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, B.; Cotton, W.R. [Colorado State Univ., Fort Collins, CO (United States); Feingold, G. [Cooperative Institute for Research in the Atmospheric (CIRA), Fort Collins, CO (United States)

    1996-04-01

    Over the past decade or so the evolution and equilibria of persistent decks of stratocumulus climatologically clinging to the edge of summertime subtropical highs have been an issue of increased scientific inquiry. The particular interest in the microphysical structure of these clouds stems from a variety of hypotheses which suggest that anthropogenic influences or biogenic feedbacks may alter the structure of these clouds in a climatically significant manner. Most of these hypotheses are quite tentative, based as they are on simple formulations of boundary layer structures and interactions between drops and aerosols. This work is concerned with an assessment of the microphysical structure of marine stratocumulus as simulated by an LES-EM model.

  2. Characteristics of vertical velocity in marine stratocumulus: comparison of large eddy simulations with observations

    International Nuclear Information System (INIS)

    Guo Huan; Liu Yangang; Daum, Peter H; Senum, Gunnar I; Tao, W-K

    2008-01-01

    We simulated a marine stratus deck sampled during the Marine Stratus/Stratocumulus Experiment (MASE) with a three-dimensional large eddy simulation (LES) model at different model resolutions. Various characteristics of the vertical velocity from the model simulations were evaluated against those derived from the corresponding aircraft in situ observations, focusing on standard deviation, skewness, kurtosis, probability density function (PDF), power spectrum, and structure function. Our results show that although the LES model captures reasonably well the lower-order moments (e.g., horizontal averages and standard deviations), it fails to simulate many aspects of the higher-order moments, such as kurtosis, especially near cloud base and cloud top. Further investigations of the PDFs, power spectra, and structure functions reveal that compared to the observations, the model generally underestimates relatively strong variations on small scales. The results also suggest that increasing the model resolutions improves the agreements between the model results and the observations in virtually all of the properties that we examined. Furthermore, the results indicate that a vertical grid size <10 m is necessary for accurately simulating even the standard-deviation profile, posing new challenges to computer resources.

  3. Coupling spectral-bin cloud microphysics with the MOSAIC aerosol model in WRF-Chem: Methodology and results for marine stratocumulus clouds

    Science.gov (United States)

    Gao, Wenhua; Fan, Jiwen; Easter, R. C.; Yang, Qing; Zhao, Chun; Ghan, Steven J.

    2016-09-01

    Aerosol-cloud interaction processes can be represented more physically with bin cloud microphysics relative to bulk microphysical parameterizations. However, due to computational power limitations in the past, bin cloud microphysics was often run with very simple aerosol treatments. The purpose of this study is to represent better aerosol-cloud interaction processes in the Chemistry version of Weather Research and Forecast model (WRF-Chem) at convection-permitting scales by coupling spectral-bin cloud microphysics (SBM) with the MOSAIC sectional aerosol model. A flexible interface is built that exchanges cloud and aerosol information between them. The interface contains a new bin aerosol activation approach, which replaces the treatments in the original SBM. It also includes the modified aerosol resuspension and in-cloud wet removal processes with the droplet loss tendencies and precipitation fluxes from SBM. The newly coupled system is evaluated for two marine stratocumulus cases over the Southeast Pacific Ocean with either a simplified aerosol setup or full-chemistry. We compare the aerosol activation process in the newly coupled SBM-MOSAIC against the SBM simulation without chemistry using a simplified aerosol setup, and the results show consistent activation rates. A longer time simulation reinforces that aerosol resuspension through cloud drop evaporation plays an important role in replenishing aerosols and impacts cloud and precipitation in marine stratocumulus clouds. Evaluation of the coupled SBM-MOSAIC with full-chemistry using aircraft measurements suggests that the new model works realistically for the marine stratocumulus clouds, and improves the simulation of cloud microphysical properties compared to a simulation using MOSAIC coupled with the Morrison two-moment microphysics.

  4. Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem

    Directory of Open Access Journals (Sweden)

    Q. Yang

    2011-12-01

    Full Text Available This study assesses the ability of the recent chemistry version (v3.3 of the Weather Research and Forecasting (WRF-Chem model to simulate boundary layer structure, aerosols, stratocumulus clouds, and energy fluxes over the Southeast Pacific Ocean. Measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx and satellite retrievals (i.e., products from the MODerate resolution Imaging Spectroradiometer (MODIS, Clouds and Earth's Radiant Energy System (CERES, and GOES-10 are used for this assessment. The Morrison double-moment microphysics scheme is newly coupled with interactive aerosols in the model. The 31-day (15 October–16 November 2008 WRF-Chem simulation with aerosol-cloud interactions (AERO hereafter is also compared to a simulation (MET hereafter with fixed cloud droplet number concentrations in the microphysics scheme and simplified cloud and aerosol treatments in the radiation scheme. The well-simulated aerosol quantities (aerosol number, mass composition and optical properties, and the inclusion of full aerosol-cloud couplings lead to significant improvements in many features of the simulated stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness. In addition to accounting for the aerosol direct and semi-direct effects, these improvements feed back to the simulation of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengthens the temperature and humidity gradients within the capping inversion layer and lowers the marine boundary layer (MBL depth by 130 m from that of the MET simulation. These differences are associated with weaker entrainment and stronger mean subsidence at the top of the MBL in AERO. Mean top-of-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with

  5. Aerosol Indirect effect on Stratocumulus Organization

    Science.gov (United States)

    Zhou, X.; Heus, T.; Kollias, P.

    2015-12-01

    Large-eddy simulations are used to investigate the role of aerosol loading on organized Stratocumulus. We prescribed the cloud droplet number concentration (Nc) and considered it as the proxy for different aerosol loading. While the presence of drizzle amplifies the mesoscale variability as is in Savic-Jovcic and Stevens (JAS, 2008), two noticeable findings are discussed here: First, the scale of marine boundary layer circulation appears to be independent of aerosol loading, suggesting a major role of the turbulence. The precise role of the turbulence in stratocumulus organization is studied by modifying the large scale fluctuations from the LES domain. Second, while it is commonly thought that the whole circulation needs to be represented for robust cloud development, we find that stratocumulus dynamics, including variables like w'w' and w'w'w', are remarkably robust even if large scales are ignored by simply reducing the domain sizes. The only variable that is sensitive to the change of the scale is the amount of cloudiness. Despite their smaller cloud thickness and inhomogeneous macroscopic structure for low Nc, individual drizzling clouds have sizes that are commensurate with circulation scale. We observe an Nc threshold below which stratocumulus is thin enough so that a little decrease of Nc would lead to great change of cloud fraction. The simulated cloud albedo is more sensitive to in-cloud liquid water content than to the amount of cloudiness since the former decreases at least three times faster than the latter due to drizzle. The main impact of drizzle evaporation is observed to keep the sub-cloud layer moist and as a result to extend the lifetime of stratocumulus by a couple of hours.

  6. Slow Manifolds and Multiple Equilibria in Stratocumulus-Capped Boundary Layers

    Directory of Open Access Journals (Sweden)

    Junya Uchida

    2010-12-01

    Full Text Available In marine stratocumulus-capped boundary layers under strong inversions, the timescale for thermodynamic adjustment is roughly a day, much shorter than the multiday timescale for inversion height adjustment. Slow-manifold analysis is introduced to exploit this timescale separation when boundary layer air columns experience only slow changes in their boundary conditions. Its essence is that the thermodynamic structure of the boundary layer remains approximately slaved to its inversion height and the instantaneous boundary conditions; this slaved structure determines the entrainment rate and hence the slow evolution of the inversion height. Slow-manifold analysis is shown to apply to mixed-layer model and large-eddy simulations of an idealized nocturnal stratocumulus- capped boundary layer; simulations with different initial inversion heights collapse onto single relationships of cloud properties with inversion height. Depending on the initial inversion height, the simulations evolve toward a shallow thin-cloud boundary layer or a deep, well-mixed thick cloud boundary layer. In the large-eddy simulations, these evolutions occur on two separate slow manifolds (one of which becomes unstable if cloud droplet concentration is reduced. Applications to analysis of stratocumulus observations and to pockets of open cells and ship tracks are proposed.

  7. Skill of ship-following large-eddy simulations in reproducing MAGIC observations across the northeast Pacific stratocumulus to cumulus transition region

    Science.gov (United States)

    McGibbon, J.; Bretherton, C. S.

    2017-06-01

    During the Marine ARM GPCI Investigation of Clouds (MAGIC) in October 2011 to September 2012, a container ship making periodic cruises between Los Angeles, CA, and Honolulu, HI, was instrumented with surface meteorological, aerosol and radiation instruments, a cloud radar and ceilometer, and radiosondes. Here large-eddy simulation (LES) is performed in a ship-following frame of reference for 13 four day transects from the MAGIC field campaign. The goal is to assess if LES can skillfully simulate the broad range of observed cloud characteristics and boundary layer structure across the subtropical stratocumulus to cumulus transition region sampled during different seasons and meteorological conditions. Results from Leg 15A, which sampled a particularly well-defined stratocumulus to cumulus transition, demonstrate the approach. The LES reproduces the observed timing of decoupling and transition from stratocumulus to cumulus and matches the observed evolution of boundary layer structure, cloud fraction, liquid water path, and precipitation statistics remarkably well. Considering the simulations of all 13 cruises, the LES skillfully simulates the mean diurnal variation of key measured quantities, including liquid water path (LWP), cloud fraction, measures of decoupling, and cloud radar-derived precipitation. The daily mean quantities are well represented, and daily mean LWP and cloud fraction show the expected correlation with estimated inversion strength. There is a -0.6 K low bias in LES near-surface air temperature that results in a high bias of 5.6 W m-2 in sensible heat flux (SHF). Overall, these results build confidence in the ability of LES to represent the northeast Pacific stratocumulus to trade cumulus transition region.Plain Language SummaryDuring the Marine ARM GPCI Investigation of Clouds (MAGIC) field campaign in October 2011 to September 2012, a cargo container ship making regular cruises between Los Angeles, CA, and Honolulu, HI, was fitted with tools to

  8. Evaluating aerosol indirect effect through marine stratocumulus clouds

    Energy Technology Data Exchange (ETDEWEB)

    Kogan, Z.N.; Kogan, Y.L.; Lilly, D.K. [Univ. of Oklahoma, Norman, OK (United States)

    1996-04-01

    During the last decade much attention has been focused on anthropogenic aerosols and their radiative influence on the global climate. Charlson et al. and Penner et al. have demonstrated that tropospheric aerosols and particularly anthropogenic sulfate aerosols may significantly contribute to the radiative forcing exerting a cooling influence on climate (-1 to -2 W/m{sup 2}) which is comparable in magnitude to greenhouse forcing, but opposite in sign. Aerosol particles affect the earth`s radiative budget either directly by scattering and absorption of solar radiation by themselves or indirectly by altering the cloud radiative properties through changes in cloud microstructure. Marine stratocumulus cloud layers and their possible cooling influence on the atmosphere as a result of pollution are of special interest because of their high reflectivity, durability, and large global cover. We present an estimate of thet aerosol indirect effect, or, forcing due to anthropogenic sulfate aerosols.

  9. Ozone budgets from the Dynamics and Chemistry of Marine Stratocumulus experiment

    Science.gov (United States)

    Kawa, S. R.; Pearson, R., Jr.

    1989-01-01

    Measurements from the Dynamics and Chemistry of marine Stratocumulus experiment have been used to study components of the regional ozone budget. The surface destruction rate is determined by eddy correlation of ozone and vertical velocity measured by a low-flying aircraft. Significant variability is found in the measured surface resistance; it is partially correlated with friction velocity but appears to have other controlling influences as well. The mean resistance is 4190 s/m which is higher (slower destruction) than most previous estimates for seawater. Flux and mean measurements throughout the marine boundary layer are used to estimate the net rate of in situ photochemical production/destruction of ozone. Averaged over the flights, ozone concentration is found to be near steady state, and a net of photochemical destruction of 0.02-0.07 ng/cu m per sec is diagnosed. This is an important confirmation of photochemical model results for the remote marine boundary layer. Ozone vertical distributions above the boundary layer show a strongly layered structure with very sharp gradients. These distributions are possibly related to the stratospheric ozone source.

  10. Observational and Numerical Studies of the Boundary Layer, Cloud, and Aerosol Variability in the Southeast Pacific Coastal Marine Stratocumulus

    Science.gov (United States)

    2012-05-01

    Malinowski , J.-L., Brenguier and F. Burnet, 2005: Holes and entrainment in stratocumulus, J. Atmos. Sci., 62, 443-459. Ghate, V. P., B. A...Tennessee. Haman, K. E., S. P. Malinowski , M. J. Kurowski, H. Gerber, and J.-L. Brenguier, 2007: Small scale mixing processes at the top of a marine

  11. Stratocumulus Cloud Top Radiative Cooling and Cloud Base Updraft Speeds

    Science.gov (United States)

    Kazil, J.; Feingold, G.; Balsells, J.; Klinger, C.

    2017-12-01

    Cloud top radiative cooling is a primary driver of turbulence in the stratocumulus-topped marine boundary. A functional relationship between cloud top cooling and cloud base updraft speeds may therefore exist. A correlation of cloud top radiative cooling and cloud base updraft speeds has been recently identified empirically, providing a basis for satellite retrieval of cloud base updraft speeds. Such retrievals may enable analysis of aerosol-cloud interactions using satellite observations: Updraft speeds at cloud base co-determine supersaturation and therefore the activation of cloud condensation nuclei, which in turn co-determine cloud properties and precipitation formation. We use large eddy simulation and an off-line radiative transfer model to explore the relationship between cloud-top radiative cooling and cloud base updraft speeds in a marine stratocumulus cloud over the course of the diurnal cycle. We find that during daytime, at low cloud water path (CWP correlated, in agreement with the reported empirical relationship. During the night, in the absence of short-wave heating, CWP builds up (CWP > 50 g m-2) and long-wave emissions from cloud top saturate, while cloud base heating increases. In combination, cloud top cooling and cloud base updrafts become weakly anti-correlated. A functional relationship between cloud top cooling and cloud base updraft speed can hence be expected for stratocumulus clouds with a sufficiently low CWP and sub-saturated long-wave emissions, in particular during daytime. At higher CWPs, in particular at night, the relationship breaks down due to saturation of long-wave emissions from cloud top.

  12. A treatment for the stratocumulus-to-cumulus transition in GCMs

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Heng; Mechoso, C.R. [University of California, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA (United States); Wu, Chien-Ming [National Taiwan University, Department of Atmospheric Sciences, Taipei (China); Ma, Hsi-Yen [Lawrence Livermore National Laboratory, Program for Climate Model Diagnosis and Intercomparison, Livermore, CA (United States)

    2012-12-15

    Numerical models of climate have great difficulties with the simulation of marine low clouds in the subtropical Pacific and Atlantic Oceans. It has been especially difficult to reproduce the observed geographical distributions of the different cloud regimes in those regions. The present study discusses mechanisms proposed in previous works for changing one regime into another. One criterion is based on the theory of stratocumulus destruction through cloud top entrainment instability due to buoyancy reversal - situations in which the mixture of two air parcels becomes denser than either of the original parcels due to evaporation of cloud water. Another criterion is based on the existence of decoupling in the boundary layer. When decoupled, the stratocumulus regime changes to another in which these clouds can still exist together with cumulus. In a LES study, the authors have suggested that a combination of those two criteria can be used to diagnose whether, at a location, the cloud regime corresponds to a well-mixed stratocumulus regime, a shallow cumulus regime, or to a transitional regime where the boundary layer is decoupled. The concept is tested in the framework of an atmospheric general circulation model (GCM). It is found that several outstanding features of disagreement between simulation and observation can be interpreted as misrepresentations of the cloud regimes by the GCM. A novel criterion for switching among regimes is proposed to alleviate the effects of these misrepresentations. (orig.)

  13. An LES model study of the influence of the free tropospheric thermodynamic conditions on the stratocumulus response to a climate perturbation

    NARCIS (Netherlands)

    Van der Dussen, J.J.; De Roode, S.R.; Dal Gesso, S.; Siebesma, A.P.

    2015-01-01

    Twenty-five large-eddy simulations are performed to study how free tropospheric thermodynamic conditions control equilibrium state solutions of stratocumulus-topped marine boundary layers. In particular, we systematically vary the lower tropospheric stability (LTS) and a similar measure for the bulk

  14. The radiation budget of stratocumulus clouds measured by tethered balloon instrumentation: Variability of flux measurements

    Science.gov (United States)

    Duda, David P.; Stephens, Graeme L.; Cox, Stephen K.

    1990-01-01

    Measurements of longwave and shortwave radiation were made using an instrument package on the NASA tethered balloon during the FIRE Marine Stratocumulus experiment. Radiation data from two pairs of pyranometers were used to obtain vertical profiles of the near-infrared and total solar fluxes through the boundary layer, while a pair of pyrgeometers supplied measurements of the longwave fluxes in the cloud layer. The radiation observations were analyzed to determine heating rates and to measure the radiative energy budget inside the stratocumulus clouds during several tethered balloon flights. The radiation fields in the cloud layer were also simulated by a two-stream radiative transfer model, which used cloud optical properties derived from microphysical measurements and Mie scattering theory.

  15. Stratocumulus to Cumulus Transition by Drizzle

    Science.gov (United States)

    Yamaguchi, Takanobu; Feingold, Graham; Kazil, Jan

    2017-10-01

    The stratocumulus to cumulus transition (SCT) is typically considered to be a slow, multiday process, caused primarily by dry air entrainment associated with overshooting cumulus, with minor influence of drizzle. This study revisits the role of drizzle in the SCT with large eddy simulations coupled with a two-moment bulk microphysics scheme that includes a budget on aerosol (Na) and cloud droplet number concentrations (Nc). We show a strong precipitation-induced modulation of the SCT by drizzle initiated in penetrative cumulus under stratocumulus. Lagrangian SCT simulations are initiated with various, moderate Na (100-250 cm-3), which produce little to no drizzle from the stratocumulus. As expected, drizzle formation in cumuli is regulated by cloud depth and Nc, with stronger dependence on cloud depth, so that, for the current case, drizzle is generated in all simulations once cumulus clouds become sufficiently deep. The drizzle generated in the cumuli washes out stratocumulus cloud water and much of the aerosol, and a cumulus state appears for approximately 10 h. With additional simulations with a fixed Nc (100 cm-3), we show that prediction of Nc is necessary for this fast SCT since it is a result of a positive feedback of collision-coalescence-induced aerosol depletion that enhances drizzle formation. A fixed Nc does not permit this feedback, and thus results in weak influence of drizzle on the SCT. Simulations with fixed droplet concentrations that bracket the time varying aerosol/drop concentrations are therefore not representative of the role of drizzle in the SCT.

  16. Marine Stratocumulus Properties from the FPDR - PDI as a Function of Aerosol during ORACLES

    Science.gov (United States)

    Small Griswold, J. D.; Heikkila, A.

    2016-12-01

    Aerosol-cloud interactions in the southeastern Atlantic (SEA) region were investigated during year 1 of the ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field project in Aug-Sept 2016. This region is of interest due to seasonally persistent marine stratocumulus cloud decks that are an important component of the climate system due to their radiative and hydrologic impacts. The SEA deck is unique due to the interactions between these clouds and transported biomass burning aerosol during the July-October fire season. These biomass burning aerosol play multiple roles in modifying the cloud deck through interactions with radiation as absorbing aerosol and through modifications to cloud microphysical properties as cloud condensation nuclei. This work uses in situcloud data obtained with a Flight Probe Dual Range - Phase Doppler Interferometer (FPDR - PDI), standard aerosol instrumentation on board the NASA P-3, and reanalysis data to investigate Aerosol-Cloud Interactions (ACI). The FPDR - PDI provides unique cloud microphysical observations of individual cloud drop arrivals allowing for the computation of a variety of microphysical cloud properties including individual drop size, cloud drop number concentration, cloud drop size distributions, liquid water content, and cloud thickness. The FPDR - PDI measurement technique also provides droplet spacing and drop velocity information which is used to investigate turbulence and entrainment mixing processes. We use aerosol information such as average background aerosol amount (low, mid, high) and location relative to cloud (above or mixing) to sort FPDR - PDI cloud properties. To control for meteorological co-variances we further sort the data within aerosol categories by lower tropospheric stability, vertical velocity, and surface wind direction. We then determine general marine stratocumulus cloud characteristics under each of the various aerosol categories to investigate ACI in the SEA.

  17. The GASS/EUCLIPSE model intercomparison of the stratocumulus transition as observed during ASTEX : LES results

    NARCIS (Netherlands)

    Van der Dussen, J.J.; De Roode, S.R.; Ackerman, A.S.; Blossey, P.N.; Bretherton, C.S.; Kurowski, M.J.; Lock, A.P.; Neggers, R.A.J.; Sandu, I.; Siebesma, A.P.

    2013-01-01

    Large-eddy simulations of a Lagrangian transition from a vertically well-mixed stratocumulus-topped boundary layer to a situation in which shallow cumuli penetrate an overlying layer of thin and broken stratocumulus are compared with aircraft observations collected during the Atlantic Stratocumulus

  18. Twomey effect in subtropical stratocumulus clouds from UV depolarization lidar

    NARCIS (Netherlands)

    de Graaf, M.; Brown, Jessica; Donovan, D.P.; Nicolae, D.; Makoto, A.; Vassilis, A.; Balis, D.; Behrendt, A.; Comeron, A.; Gibert, F.; Landulfo, E.; McCormick, M.P.; Senff, C.; Veselovskii, I.; Wandinger, U.

    2018-01-01

    Marine stratocumulus clouds are important climate regulators, reflecting sunlight over a dark ocean background. A UV-depolarization lidar on Ascension, a small remote island in the south Atlantic, measured cloud droplet sizes and number concentration using an inversion method based on Monte Carlo

  19. How large-scale subsidence affects stratocumulus transitions

    Directory of Open Access Journals (Sweden)

    J. J. van der Dussen

    2016-01-01

    Full Text Available Some climate modeling results suggest that the Hadley circulation might weaken in a future climate, causing a subsequent reduction in the large-scale subsidence velocity in the subtropics. In this study we analyze the cloud liquid water path (LWP budget from large-eddy simulation (LES results of three idealized stratocumulus transition cases, each with a different subsidence rate. As shown in previous studies a reduced subsidence is found to lead to a deeper stratocumulus-topped boundary layer, an enhanced cloud-top entrainment rate and a delay in the transition of stratocumulus clouds into shallow cumulus clouds during its equatorwards advection by the prevailing trade winds. The effect of a reduction of the subsidence rate can be summarized as follows. The initial deepening of the stratocumulus layer is partly counteracted by an enhanced absorption of solar radiation. After some hours the deepening of the boundary layer is accelerated by an enhancement of the entrainment rate. Because this is accompanied by a change in the cloud-base turbulent fluxes of moisture and heat, the net change in the LWP due to changes in the turbulent flux profiles is negligibly small.

  20. Biomass smoke from southern Africa can significantly enhance the brightness of stratocumulus over the southeastern Atlantic Ocean

    Science.gov (United States)

    Lu, Zheng; Liu, Xiaohong; Zhang, Zhibo; Zhao, Chun; Meyer, Kerry; Rajapakshe, Chamara; Wu, Chenglai; Yang, Zhifeng; Penner, Joyce E.

    2018-03-01

    Marine stratocumulus clouds cover nearly one-quarter of the ocean surface and thus play an extremely important role in determining the global radiative balance. The semipermanent marine stratocumulus deck over the southeastern Atlantic Ocean is of particular interest, because of its interactions with seasonal biomass burning aerosols that are emitted in southern Africa. Understanding the impacts of biomass burning aerosols on stratocumulus clouds and the implications for regional and global radiative balance is still very limited. Previous studies have focused on assessing the magnitude of the warming caused by solar scattering and absorption by biomass burning aerosols over stratocumulus (the direct radiative effect) or cloud adjustments to the direct radiative effect (the semidirect effect). Here, using a nested modeling approach in conjunction with observations from multiple satellites, we demonstrate that cloud condensation nuclei activated from biomass burning aerosols entrained into the stratocumulus (the microphysical effect) can play a dominant role in determining the total radiative forcing at the top of the atmosphere, compared with their direct and semidirect radiative effects. Biomass burning aerosols over the region and period with heavy loadings can cause a substantial cooling (daily mean ‑8.05 W m‑2), primarily as a result of clouds brightening by reducing the cloud droplet size (the Twomey effect) and secondarily through modulating the diurnal cycle of cloud liquid water path and coverage (the cloud lifetime effect). Our results highlight the importance of realistically representing the interactions of stratocumulus with biomass burning aerosols in global climate models in this region.

  1. New pathway of stratocumulus to cumulus transition via aerosol-cloud-precipitation interaction

    Science.gov (United States)

    Yamaguchi, T.; Feingold, G.; Kazil, J.

    2017-12-01

    The stratocumulus to cumulus transition (SCT) is typically considered to be a slow, multi-day process, caused primarily by dry air entrainment associated with overshooting cumulus rising under stratocumulus, with minor influence of precipitation. In this presentation, we show rapid SCT induced by a strong precipitation-induced modulation with Lagrangian SCT large eddy simulations. A large eddy model is coupled with a two-moment bulk microphysics scheme that predicts aerosol and droplet number concentrations. Moderate aerosol concentrations (100-250 cm-3) produce little to no drizzle from the stratocumulus deck. Large amounts of rain eventually form and wash out stratocumulus and much of the aerosol, and a cumulus state appears for approximately 10 hours. Initiation of strong rain formation is identified in penetrative cumulus clouds which are much deeper than stratocumulus, and they are able to condense large amounts of water. We show that prediction of cloud droplet number is necessary for this fast SCT since it is a result of a positive feedback of collision-coalescence induced aerosol depletion enhancing drizzle formation. Simulations with fixed droplet concentrations that bracket the time varying aerosol/drop concentrations are therefore not representative of the role of drizzle in the SCT.

  2. Evaluation of stratocumulus cloud prediction in the Met Office forecast model during VOCALS-REx

    Directory of Open Access Journals (Sweden)

    S. J. Abel

    2010-11-01

    Full Text Available Observations in the subtropical southeast Pacific obtained during the VOCALS-REx field experiment are used to evaluate the representation of stratocumulus cloud in the Met Office forecast model and to identify key areas where model biases exist. Marked variations in the large scale structure of the cloud field were observed during the experiment on both day-to-day and on diurnal timescales. In the remote maritime region the model is shown to have a good representation of synoptically induced variability in both cloud cover and marine boundary layer depth. Satellite observations show a strong diurnal cycle in cloud fraction and liquid water path in the stratocumulus with enhanced clearances of the cloud deck along the Chilean and Peruvian coasts on certain days. The model accurately simulates the phase of the diurnal cycle but is unable to capture the coastal clearing of cloud. Observations along the 20° S latitude line show a gradual increase in the depth of the boundary layer away from the coast. This trend is well captured by the model (typical low bias of 200 m although significant errors exist at the coast where the model marine boundary layer is too shallow and moist. Drizzle in the model responds to changes in liquid water path in a manner that is consistent with previous ship-borne observations in the region although the intensity of this drizzle is likely to be too high, particularly in the more polluted coastal region where higher cloud droplet number concentrations are typical. Another mode of variability in the cloud field that the model is unable to capture are regions of pockets of open cellular convection embedded in the overcast stratocumulus deck and an example of such a feature that was sampled during VOCALS-REx is shown.

  3. Simulation of Optical Properties and Direct and Indirect Radiative Effects of Smoke Aerosols Over Marine Stratocumulus Clouds During Summer 2008 in California With the Regional Climate Model RegCM

    Science.gov (United States)

    Mallet, M.; Solmon, F.; Roblou, L.; Peers, F.; Turquety, S.; Waquet, F.; Jethva, H.; Torres, O.

    2017-10-01

    The regional climate model RegCM has been modified to better account for the climatic effects of biomass-burning particles. Smoke aerosols are represented by new tracers with consistent radiative and hygroscopic properties to simulate the direct radiative forcing (DRF), and a new parameterization has been integrated for relating the droplet number concentration to the aerosol concentration for marine stratocumulus clouds (Sc). RegCM has been tested during the summer of 2008 over California, when extreme concentration of smoke, together with the presence of Sc, is observed. This work indicates that significant aerosol optical depth (AOD) ( 1-2 at 550 nm) is related to the intense 2008 fires. Compared to Ozone Monitoring Instrument (OMI) and Moderate Resolution Imaging Spectroradiometer, the regional pattern of RegCM AOD is well represented although the magnitude is lower than satellite observations. Comparisons with Polarization and Directionality of Earth Reflectances (POLDER) above-clouds aerosol optical depth (ACAOD) show the ability of RegCM to simulate realistic ACAOD during the transport of smoke above the Pacific Ocean. The simulated single scattering albedo is 0.90 (at 550 nm) near biomass-burning sources, consistent with OMI and POLDER, and smoke leads to shortwave heating rates 1.5-2°K d-1. RegCM is not able to correctly resolve the daily patterns in cloud properties notably due to its coarse horizontal resolutions. However, the changes in the sign of the DRF at top of atmosphere (TOA) (negative to positive) from clear-sky to all-sky conditions is well simulated. Finally, the "aerosol-cloud" parameterization allows simulating an increase of the cloud optical depth for significant concentrations, leading to large perturbations of radiative fluxes at TOA.

  4. Large Eddy Simulation of the Diurnal Cycle in Southeast Pacific Stratocumulus

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, P; Bretherton, C

    2008-03-03

    This paper describes a series of 6 day large eddy simulations of a deep, sometimes drizzling stratocumulus-topped boundary layer based on forcings from the East Pacific Investigation of Climate (EPIC) 2001 field campaign. The base simulation was found to reproduce the observed mean boundary layer properties quite well. The diurnal cycle of liquid water path was also well captured, although good agreement appears to result partially from compensating errors in the diurnal cycles of cloud base and cloud top due to overentrainment around midday. At other times of the day, entrainment is found to be proportional to the vertically-integrated buoyancy flux. Model stratification matches observations well; turbulence profiles suggest that the boundary layer is always at least somewhat decoupled. Model drizzle appears to be too sensitive to liquid water path and subcloud evaporation appears to be too weak. Removing the diurnal cycle of subsidence had little effect on simulated cloud albedo. Simulations with changed droplet concentration and drizzle susceptibility showed large liquid water path differences at night, but differences were quite small at midday. Droplet concentration also had a significant impact on entrainment, primarily through droplet sedimentation feedback rather than through drizzle processes.

  5. Effect of biomass burning on marine stratocumulus clouds off the California coast

    Directory of Open Access Journals (Sweden)

    E.-Y. Hsie

    2009-11-01

    Full Text Available Aerosol-cloud interactions are considered to be one of the most important and least known forcings in the climate system. Biomass burning aerosols are of special interest due to their radiative impact (direct and indirect effect and their potential to increase in the future due to climate change. Combining data from Geostationary Operational Environmental Satellite (GOES and MODerate-resolution Imaging Spectroradiometer (MODIS with passive tracers from the FLEXPART Lagrangian Particle Dispersion Model, the impact of biomass burning aerosols on marine stratocumulus clouds has been examined in June and July of 2006–2008 off the California coast. Using a continental tracer, the indirect effect of biomass burning aerosols has been isolated by comparing the average cloud fraction and cloud albedo for different meteorological situations, and for clean versus polluted (in terms of biomass burning continental air masses at 14:00 local time. Within a 500 km-wide band along the coast of California, biomass burning aerosols, which tend to reside above the marine boundary layer, increased the cloud fraction by 0.143, and the cloud albedo by 0.038. Absorbing aerosols located above the marine boundary layer lead to an increase of the lower tropospheric stability and a reduction in the vertical entrainment of dry air from above, leading to increased cloud formation. The combined effect was an indirect radiative forcing of −7.5% ±1.7% (cooling effect of the outgoing radiative flux at the top of the atmosphere on average, with a bias due to meteorology of +0.9%. Further away from the coast, the biomass burning aerosols, which were located within the boundary layer, reduced the cloud fraction by 0.023 and the cloud albedo by 0.006, resulting in an indirect radiative forcing of +1.3% ±0.3% (warming effect with a bias of +0.5%. These results underscore the dual role that absorbing aerosols play in cloud radiative forcing.

  6. Drizzle production in stratocumulus

    Energy Technology Data Exchange (ETDEWEB)

    Feingold, G.; Frisch, A.S.; Stevens, B.; Cotton, W.R. [Colorado State Univ., Fort Collins, CO (United States)

    1996-04-01

    Although stratocumulus clouds are not prodigious producers of precipitation, the small amounts of drizzle they do produce have an important impact on both cloud macrophysical properties (e.g., spatial coverage, depth and liquid water content) and microphysical properties (e.g., droplet size distributions, effective radii). The radiative effects of stratocumulus are intimately connected to both these macro- and microphysical properties, and it is thus essential that we understand the mechanisms of droplet growth which generate precipitation sized droplets. Drizzle production is closely related to cloud condensation nucleus (CCN) number and size, as well as to cloud dynamics and the ability of clouds to support droplets within their bounds and allow for repeated collision-coalesence cycles. In order to address both the microphysical and dynamical aspects of drizzle formation (and their close coupling), we have adapted a large eddy simulation (LES) model to include explicit (size-resolving) microphysical treatment of the CCN and droplet spectra. By directly calculating processes such as droplet growth by condensation and stochastic collection, evaporation, and sedimentation in the LES framework, we are in a position to elucidate the drizzle formation process.

  7. Optical and Microphysical Retrievals of Marine Stratocumulus Clouds off the Coast of Namibia from Satellite and Aircraft

    Science.gov (United States)

    Platnick, Steven E.

    2010-01-01

    Though the emphasis of the Southern Africa Regional Science Initiative 2000 (SAFARI-2000) dry season campaign was largely on emission sources and transport, the assemblage of aircraft (including the high altitude NASA ER-2 remote sensing platform and the University of Washington CV-580, UK MRF C-130, and South African Weather Bureau JRA in situ aircrafts) provided a unique opportunity for cloud studies. Therefore, as part of the SAFARI initiative, investigations were undertaken to assess regional aerosol-cloud interactions and cloud remote sensing algorithms. In particular, the latter part of the experiment concentrated on marine boundary layer stratocumulus clouds off the southwest coast of Africa. Associated with cold water upwelling along the Benguela current, the Namibian stratocumulus regime has received limited attention but appears to be unique for several reasons. During the dry season, outflow of continental fires and industrial pollution over this area can be extreme. From below, upwelling provides a rich nutrient source for phytoplankton (a source of atmospheric sulfur through DMS production as well as from decay processes). The impact of these natural and anthropogenic sources on the microphysical and optical properties of the stratocumulus is unknown. Continental and Indian Ocean cloud systems of opportunity were also studied during the campaign. SAFARI 2000 aircraft flights off the coast of Namibia were coordinated with NASA Terra Satellite overpasses for synergy with the Moderate Resolution Imaging Spectroradiometer (MODIS) and other Terra instruments. MODIS was developed by NASA and launched onboard the Terra spacecraft on December 18, 1999 (and Aqua spacecraft on May 4, 2002). Among the remote sensing algorithms developed and applied to this sensor are cloud optical and microphysical properties that include cloud thermodynamic phase, optical thickness, and effective particle radius of both liquid water and ice clouds. The archived products from

  8. Relating large-scale subsidence to convection development in Arctic mixed-phase marine stratocumulus

    Science.gov (United States)

    Young, Gillian; Connolly, Paul J.; Dearden, Christopher; Choularton, Thomas W.

    2018-02-01

    Large-scale subsidence, associated with high-pressure systems, is often imposed in large-eddy simulation (LES) models to maintain the height of boundary layer (BL) clouds. Previous studies have considered the influence of subsidence on warm liquid clouds in subtropical regions; however, the relationship between subsidence and mixed-phase cloud microphysics has not specifically been studied. For the first time, we investigate how widespread subsidence associated with synoptic-scale meteorological features can affect the microphysics of Arctic mixed-phase marine stratocumulus (Sc) clouds. Modelled with LES, four idealised scenarios - a stable Sc, varied droplet (Ndrop) or ice (Nice) number concentrations, and a warming surface (representing motion southwards) - were subjected to different levels of subsidence to investigate the cloud microphysical response. We find strong sensitivities to large-scale subsidence, indicating that high-pressure systems in the ocean-exposed Arctic regions have the potential to generate turbulence and changes in cloud microphysics in any resident BL mixed-phase clouds.Increased cloud convection is modelled with increased subsidence, driven by longwave radiative cooling at cloud top and rain evaporative cooling and latent heating from snow growth below cloud. Subsidence strengthens the BL temperature inversion, thus reducing entrainment and allowing the liquid- and ice-water paths (LWPs, IWPs) to increase. Through increased cloud-top radiative cooling and subsequent convective overturning, precipitation production is enhanced: rain particle number concentrations (Nrain), in-cloud rain mass production rates, and below-cloud evaporation rates increase with increased subsidence.Ice number concentrations (Nice) play an important role, as greater concentrations suppress the liquid phase; therefore, Nice acts to mediate the strength of turbulent overturning promoted by increased subsidence. With a warming surface, a lack of - or low - subsidence

  9. Low cloud precipitation climatology in the southeastern Pacific marine stratocumulus region using CloudSat

    International Nuclear Information System (INIS)

    Rapp, Anita D; Lebsock, Matthew; L’Ecuyer, Tristan

    2013-01-01

    A climatology of low cloud surface precipitation occurrence and intensity from the new CloudSat 2C-RAIN-PROFILE algorithm is presented from June 2006 through December 2010 for the southeastern Pacific region of marine stratocumulus. Results show that over 70% of low cloud precipitation falls as drizzle. Application of an empirical evaporation model suggests that 50–80% of the precipitation evaporates before it reaches the surface. Segregation of the CloudSat ascending and descending overpasses shows that the majority of precipitation occurs at night. Examination of the seasonal cycle shows that the precipitation is most frequent during the austral winter and spring; however there is considerable regional variability. Conditional rain rates increase from east to west with a maximum occurring in the region influenced by the South Pacific Convergence Zone. Area average rain rates are highest in the region where precipitation rates are moderate, but most frequent. The area average surface rain rate for low cloud precipitation for this region is ∼0.22 mm d −1 , in good agreement with in situ estimates, and is greatly improved over earlier CloudSat precipitation products. These results provide a much-needed quantification of surface precipitation in a region that is currently underestimated in existing satellite-based precipitation climatologies. (letter)

  10. Marine cloud brightening

    OpenAIRE

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John

    2012-01-01

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identi...

  11. Scaling analysis of cloud and rain water in marine stratocumulus and implications for scale-aware microphysical parameterizations

    Science.gov (United States)

    Witte, M.; Morrison, H.; Jensen, J. B.; Bansemer, A.; Gettelman, A.

    2017-12-01

    The spatial covariance of cloud and rain water (or in simpler terms, small and large drops, respectively) is an important quantity for accurate prediction of the accretion rate in bulk microphysical parameterizations that account for subgrid variability using assumed probability density functions (pdfs). Past diagnoses of this covariance from remote sensing, in situ measurements and large eddy simulation output have implicitly assumed that the magnitude of the covariance is insensitive to grain size (i.e. horizontal resolution) and averaging length, but this is not the case because both cloud and rain water exhibit scale invariance across a wide range of scales - from tens of centimeters to tens of kilometers in the case of cloud water, a range that we will show is primarily limited by instrumentation and sampling issues. Since the individual variances systematically vary as a function of spatial scale, it should be expected that the covariance follows a similar relationship. In this study, we quantify the scaling properties of cloud and rain water content and their covariability from high frequency in situ aircraft measurements of marine stratocumulus taken over the southeastern Pacific Ocean aboard the NSF/NCAR C-130 during the VOCALS-REx field experiment of October-November 2008. First we confirm that cloud and rain water scale in distinct manners, indicating that there is a statistically and potentially physically significant difference in the spatial structure of the two fields. Next, we demonstrate that the covariance is a strong function of spatial scale, which implies important caveats regarding the ability of limited-area models with domains smaller than a few tens of kilometers across to accurately reproduce the spatial organization of precipitation. Finally, we present preliminary work on the development of a scale-aware parameterization of cloud-rain water subgrid covariability based in multifractal analysis intended for application in large-scale model

  12. Cloud-Top Entrainment in Stratocumulus Clouds

    Science.gov (United States)

    Mellado, Juan Pedro

    2017-01-01

    Cloud entrainment, the mixing between cloudy and clear air at the boundary of clouds, constitutes one paradigm for the relevance of small scales in the Earth system: By regulating cloud lifetimes, meter- and submeter-scale processes at cloud boundaries can influence planetary-scale properties. Understanding cloud entrainment is difficult given the complexity and diversity of the associated phenomena, which include turbulence entrainment within a stratified medium, convective instabilities driven by radiative and evaporative cooling, shear instabilities, and cloud microphysics. Obtaining accurate data at the required small scales is also challenging, for both simulations and measurements. During the past few decades, however, high-resolution simulations and measurements have greatly advanced our understanding of the main mechanisms controlling cloud entrainment. This article reviews some of these advances, focusing on stratocumulus clouds, and indicates remaining challenges.

  13. Marine cloud brightening

    Science.gov (United States)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-01-01

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identified herein—have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud–albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action

  14. Marine Cloud Brightening

    Energy Technology Data Exchange (ETDEWEB)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, H.; Connolly, P.; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Philip J.; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Robert

    2012-09-07

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could - subject to satisfactory resolution of technical and scientific problems identified herein - have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seedparticle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

  15. Marine cloud brightening.

    Science.gov (United States)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-09-13

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could-subject to satisfactory resolution of technical and scientific problems identified herein-have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

  16. Analytic Closed-Form Solution of a Mixed Layer Model for Stratocumulus Clouds

    Science.gov (United States)

    Akyurek, Bengu Ozge

    Stratocumulus clouds play an important role in climate cooling and are hard to predict using global climate and weather forecast models. Thus, previous studies in the literature use observations and numerical simulation tools, such as large-eddy simulation (LES), to solve the governing equations for the evolution of stratocumulus clouds. In contrast to the previous works, this work provides an analytic closed-form solution to the cloud thickness evolution of stratocumulus clouds in a mixed-layer model framework. With a focus on application over coastal lands, the diurnal cycle of cloud thickness and whether or not clouds dissipate are of particular interest. An analytic solution enables the sensitivity analysis of implicitly interdependent variables and extrema analysis of cloud variables that are hard to achieve using numerical solutions. In this work, the sensitivity of inversion height, cloud-base height, and cloud thickness with respect to initial and boundary conditions, such as Bowen ratio, subsidence, surface temperature, and initial inversion height, are studied. A critical initial cloud thickness value that can be dissipated pre- and post-sunrise is provided. Furthermore, an extrema analysis is provided to obtain the minima and maxima of the inversion height and cloud thickness within 24 h. The proposed solution is validated against LES results under the same initial and boundary conditions. Then, the proposed analytic framework is extended to incorporate multiple vertical columns that are coupled by advection through wind flow. This enables a bridge between the micro-scale and the mesoscale relations. The effect of advection on cloud evolution is studied and a sensitivity analysis is provided.

  17. Development and impact of hooks of high droplet concentration on remote southeast Pacific stratocumulus

    Directory of Open Access Journals (Sweden)

    R. C. George

    2013-07-01

    Full Text Available Over the southeastern Pacific (SEP, droplet concentration (Nd in the typically unpolluted marine stratocumulus west of 80° W (> 1000 km offshore is periodically strongly enhanced in zonally elongated "hook"-shaped features that increase albedo. Here, we examine three hook events using the chemistry version of the Weather Research and Forecasting model (WRF-Chem with 14 km horizontal resolution, satellite data, and aircraft data from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx. A particularly strong hook yields insights into the development, decay, and radiative impact of these features. Hook development occurs with Nd increasing to polluted levels over the remote ocean primarily due to entrainment of cloud condensation nuclei (CCN from the lower free troposphere (FT. The feature advects northwestward until the FT CCN source is depleted, after which Nd decreases over a few days due to precipitation and dilution. The model suggests that the FT CCN source supplying the hook consists of high concentrations of small accumulation-mode aerosols that contribute a relatively small amount of aerosol mass to the MBL, in agreement with near-coast VOCALS measurements of polluted layers in the FT. The aerosol particles in this hook originate mainly from a pulse of offshore flow that transports Santiago-region (33–35° S emissions to the remote marine FT. To provide pollution CCN that can sustain hooks, the FT transport of pollution plumes to the remote ocean requires strong, deep offshore flow. Such flow is favored by a trough approaching the South American coast and a southeastward shift of the climatological subtropical high-pressure system. The model simulations show precipitation suppression in the hook and a corresponding increase in liquid water path (LWP compared with a simulation without anthropogenic sources. LWP also increases as the hook evolves over time due to increasing stability and decreasing subsidence. WRF

  18. Effects of biomass smoke from southern Africa on stratocumulus over southeastern Atlantic Ocean based on satellite observations and WRF-Chem model simulations

    Science.gov (United States)

    Lu, Z.; Liu, X.; Zhang, Z.; Zhao, C.; Meyer, K.; Rajapakshe, C.; Wu, C.; Yang, Z.; Penner, J.

    2017-12-01

    Each year, large amount of biomass burning (BB) aerosols are emitted over southern Africa, and transported by the predominant circulation to the southeastern Atlantic Ocean (SEA), where they overly and potentially interact with the semi-permanent stratocumulus deck in the marine boundary layer (MBL). Many previous studies suggested that the aerosol plumes are well separated from the MBL clouds, and only focused on the radiative effects of BB aerosols (direct + semi-direct radiative effects); however, as shown in several recent satellite observational studies, BB aerosols are able to be frequently entrained into the underlying clouds, function as cloud condensation nuclei (CCN), and potentially cause microphysical effects. Based on satellite observations from CATS, we found that the mixing frequencies between above-cloud aerosols and MBL clouds are very high ( 50%) over both coastal and remote regions, suggesting that BB aerosols may likely contact MBL cloud top and function as CCN quickly after they are transported over SEA. Despite the potential importance of the microphysical effect of BB aerosols over SEA, its magnitude is not fully assessed by modeling studies. In this study, we employ WRF-Chem model to study the impacts of BB aerosols on MBL stratocumulus clouds over SEA during the fire season of 2014. By designing three cases, we are able to quantitatively determine the relative importance of microphysical and radiative effects of BB aerosols. Our modeling results show that, by serving as CCN, BB aerosols are able to alter cloud properties of stratocumulus (e.g. higher cloud droplet number concentration [CDNC], higher cloud liquid water path [LWP], and larger cloud fraction [CF] before noon) and exert significant cooling effect at TOA (-8.05 Wm-2) over SEA. The cooling is primarily caused by higher CDNC (the Twomey effect), and secondarily by the changes in LWP and CF (the cloud lifetime effect). The semi-direct effect estimated in this study is smaller in

  19. Clustering, randomness, and regularity in cloud fields. 4: Stratocumulus cloud fields

    Science.gov (United States)

    Lee, J.; Chou, J.; Weger, R. C.; Welch, R. M.

    1994-01-01

    To complete the analysis of the spatial distribution of boundary layer cloudiness, the present study focuses on nine stratocumulus Landsat scenes. The results indicate many similarities between stratocumulus and cumulus spatial distributions. Most notably, at full spatial resolution all scenes exhibit a decidedly clustered distribution. The strength of the clustering signal decreases with increasing cloud size; the clusters themselves consist of a few clouds (less than 10), occupy a small percentage of the cloud field area (less than 5%), contain between 20% and 60% of the cloud field population, and are randomly located within the scene. In contrast, stratocumulus in almost every respect are more strongly clustered than are cumulus cloud fields. For instance, stratocumulus clusters contain more clouds per cluster, occupy a larger percentage of the total area, and have a larger percentage of clouds participating in clusters than the corresponding cumulus examples. To investigate clustering at intermediate spatial scales, the local dimensionality statistic is introduced. Results obtained from this statistic provide the first direct evidence for regularity among large (more than 900 m in diameter) clouds in stratocumulus and cumulus cloud fields, in support of the inhibition hypothesis of Ramirez and Bras (1990). Also, the size compensated point-to-cloud cumulative distribution function statistic is found to be necessary to obtain a consistent description of stratocumulus cloud distributions. A hypothesis regarding the underlying physical mechanisms responsible for cloud clustering is presented. It is suggested that cloud clusters often arise from 4 to 10 triggering events localized within regions less than 2 km in diameter and randomly distributed within the cloud field. As the size of the cloud surpasses the scale of the triggering region, the clustering signal weakens and the larger cloud locations become more random.

  20. Clustering, randomness, and regularity in cloud fields. 4. Stratocumulus cloud fields

    Science.gov (United States)

    Lee, J.; Chou, J.; Weger, R. C.; Welch, R. M.

    1994-07-01

    To complete the analysis of the spatial distribution of boundary layer cloudiness, the present study focuses on nine stratocumulus Landsat scenes. The results indicate many similarities between stratocumulus and cumulus spatial distributions. Most notably, at full spatial resolution all scenes exhibit a decidedly clustered distribution. The strength of the clustering signal decreases with increasing cloud size; the clusters themselves consist of a few clouds (less than 10), occupy a small percentage of the cloud field area (less than 5%), contain between 20% and 60% of the cloud field population, and are randomly located within the scene. In contrast, stratocumulus in almost every respect are more strongly clustered than are cumulus cloud fields. For instance, stratocumulus clusters contain more clouds per cluster, occupy a larger percentage of the total area, and have a larger percentage of clouds participating in clusters than the corresponding cumulus examples. To investigate clustering at intermediate spatial scales, the local dimensionality statistic is introduced. Results obtained from this statistic provide the first direct evidence for regularity among large (>900 m in diameter) clouds in stratocumulus and cumulus cloud fields, in support of the inhibition hypothesis of Ramirez and Bras (1990). Also, the size compensated point-to-cloud cumulative distribution function statistic is found to be necessary to obtain a consistent description of stratocumulus cloud distributions. A hypothesis regarding the underlying physical mechanisms responsible for cloud clustering is presented. It is suggested that cloud clusters often arise from 4 to 10 triggering events localized within regions less than 2 km in diameter and randomly distributed within the cloud field. As the size of the cloud surpasses the scale of the triggering region, the clustering signal weakens and the larger cloud locations become more random.

  1. Impacts of solar-absorbing aerosol layers on the transition of stratocumulus to trade cumulus clouds

    Directory of Open Access Journals (Sweden)

    X. Zhou

    2017-10-01

    Full Text Available The effects of an initially overlying layer of solar-absorbing aerosol on the transition of stratocumulus to trade cumulus clouds are examined using large-eddy simulations. For lightly drizzling cloud the transition is generally hastened, resulting mainly from increased cloud droplet number concentration (Nc induced by entrained aerosol. The increased Nc slows sedimentation of cloud droplets and shortens their relaxation time for diffusional growth, both of which accelerate entrainment of overlying air and thereby stratocumulus breakup. However, the decrease in albedo from cloud breakup is more than offset by redistributing cloud water over a greater number of droplets, such that the diurnal-average shortwave forcing at the top of the atmosphere is negative. The negative radiative forcing is enhanced by sizable longwave contributions, which result from the greater cloud breakup and a reduced boundary layer height associated with aerosol heating. A perturbation of moisture instead of aerosol aloft leads to a greater liquid water path and a more gradual transition. Adding absorbing aerosol to that atmosphere results in substantial reductions in liquid water path (LWP and cloud cover that lead to positive shortwave and negative longwave forcings on average canceling each other. Only for heavily drizzling clouds is the breakup delayed, as inhibition of precipitation overcomes cloud water loss from enhanced entrainment. Considering these simulations as an imperfect proxy for biomass burning plumes influencing Namibian stratocumulus, we expect regional indirect plus semi-direct forcings to be substantially negative to negligible at the top of the atmosphere, with its magnitude sensitive to background and perturbation properties.

  2. Procedure for Marine Traffic Simulation with AIS Data

    Directory of Open Access Journals (Sweden)

    Rina Miyake

    2015-03-01

    Full Text Available It is essential to evaluate safety of marine traffic for the improvement of efficiency and safety of marine traffic. Spread of AIS makes observation of actual marine traffic more easily and faster than before. Besides, description of collision avoidance behaviours of ships are indispensable to simulate a realistic marine traffic. It is important to develop and implement an algorithm of collision avoidance corresponding to a target traffic or target area into the marine traffic simulation because actual actions for collision avoidance depend on circumstances where ships are sailing. The authors developed an automated marine traffic simulation system with AIS data. And in this paper, we proposed a series of systematic procedures for marine traffic simulation including analysing for collision avoidance behaviours using AIS data.

  3. Observations of the boundary layer, cloud, and aerosol variability in the southeast Pacific coastal marine stratocumulus during VOCALS-REx

    OpenAIRE

    X. Zheng; B. Albrecht; H. H. Jonsson; D. Khelif; G. Feingold; P. Minnis; K. Ayers; P. Chuang; S. Donaher; D. Rossiter; V. Ghate; J. Ruiz-Plancarte; S. Sun-Mack

    2011-01-01

    Aircraft observations made off the coast of northern Chile in the Southeastern Pacific (20° S, 72° W; named Point Alpha) from 16 October to 13 November 2008 during the VAMOS Ocean-Cloud-Atmosphere-Land Study-Regional Experiment (VOCALS-REx), combined with meteorological reanalysis, satellite measurements, and radiosonde data, are used to investigate the boundary layer (BL) and aerosol-cloud-drizzle variations in this region. The BL at Point Alpha was typical of a non-drizzling stratocumulus-t...

  4. Sensitivity to deliberate sea salt seeding of marine clouds – observations and model simulations

    Directory of Open Access Journals (Sweden)

    K. Alterskjær

    2012-03-01

    Full Text Available Sea salt seeding of marine clouds to increase their albedo is a proposed technique to counteract or slow global warming. In this study, we first investigate the susceptibility of marine clouds to sea salt injections, using observational data of cloud droplet number concentration, cloud optical depth, and liquid cloud fraction from the MODIS (Moderate Resolution Imaging Spectroradiometer instruments on board the Aqua and Terra satellites. We then compare the derived susceptibility function to a corresponding estimate from the Norwegian Earth System Model (NorESM. Results compare well between simulations and observations, showing that stratocumulus regions off the west coast of the major continents along with large regions over the Pacific and the Indian Oceans are susceptible. At low and mid latitudes the signal is dominated by the cloud fraction.

    We then carry out geo-engineering experiments with a uniform increase over ocean of 10−9 kg m−2 s−1 in emissions of sea salt particles with a dry modal radius of 0.13 μm, an emission strength and areal coverage much greater than proposed in earlier studies. The increased sea salt concentrations and the resulting change in marine cloud properties lead to a globally averaged forcing of −4.8 W m−2 at the top of the atmosphere, more than cancelling the forcing associated with a doubling of CO2 concentrations. The forcing is large in areas found to be sensitive by using the susceptibility function, confirming its usefulness as an indicator of where to inject sea salt for maximum effect.

    Results also show that the effectiveness of sea salt seeding is reduced because the injected sea salt provides a large surface area for water vapor and gaseous sulphuric acid to condense on, thereby lowering the maximum supersaturation and suppressing the formation and lifetime of sulphate particles. In some areas, our simulations show an

  5. Simulation of a marine nuclear reactor

    International Nuclear Information System (INIS)

    Kusunoki, Tsuyoshi; Kyouya, Masahiko; Kobayashi, Hideo; Ochiai, Masaaki

    1995-01-01

    A Nuclear-powered ship Engineering Simulation SYstem (NESSY) has been developed by the Japan Atomic Energy Research Institute as an advanced design tool for research and development of future marine reactors. A marine reactor must respond to changing loads and to the ship's motions because of the ship's maneuvering and its presence in a marine environment. The NESSY has combined programs for the reactor plant behavior calculations and the ship's motion calculations. Thus, it can simulate reactor power fluctuations caused by changing loads and the ship's motions. It can also simulate the behavior of water in the pressurizer and steam generators. This water sloshes in response to the ship's motions. The performance of NESSY has been verified by comparing the simulation calculations with the measured data obtained by experiments performed using the nuclear ship Mutsu. The effects of changing loads and the ship's motions on the reactor behavior can be accurately simulated by NESSY

  6. A comparative study of the response of modeled non-drizzling stratocumulus to meteorological and aerosol perturbations

    Directory of Open Access Journals (Sweden)

    J. L. Petters

    2013-03-01

    Full Text Available The impact of changes in aerosol and cloud droplet concentration (Na and Nd on the radiative forcing of stratocumulus-topped boundary layers (STBLs has been widely studied. How these impacts compare to those due to variations in meteorological context has not been investigated in a systematic fashion for non-drizzling overcast stratocumulus. In this study we examine the impact of observed variations in meteorological context and aerosol state on daytime, non-drizzling overcast stratiform evolution, and determine how resulting changes in cloud properties compare. Using large-eddy simulation (LES we create a model base case of daytime southeast Pacific coastal stratocumulus, spanning a portion of the diurnal cycle (early morning to near noon and constrained by observations taken during the VOCALS (VAMOS Ocean-Atmosphere-Land Study field campaign. We perturb aerosol and meteorological properties around this base case to investigate the stratocumulus response. We determine perturbations in the cloud top jumps in potential temperature θ and total water mixing ratio qt from ECMWF Re-analysis Interim data, and use a set of Nd values spanning the observable range. To determine the cloud response to these meteorological and aerosol perturbations, we compute changes in liquid water path (LWP, bulk optical depth (τ and cloud radiative forcing (CRF. We find that realistic variations in the thermodynamic jump properties can elicit a response in the cloud properties of τ and shortwave (SW CRF that are on the same order of magnitude as the response found due to realistic changes in aerosol state (i.e Nd. In response to increases in Nd, the cloud layer in the base case thinned due to increases in evaporative cooling and entrainment rate. This cloud thinning somewhat mitigates the increase in τ resulting from increases in Nd. On the other hand, variations in θ and qt jumps did not substantially modify Nd. The cloud layer thickens in response to an increase

  7. Estimates for the Probabilities of Surface-to-Air Cloud-Free Lines-of-Sight and Low Cloud Statistics from Ship Observations. Part 1. Fifteen Marine Locations.

    Science.gov (United States)

    1980-11-24

    time before and after) or cumulus fractus of bad weath’er, or both ( pannus ), usually below altostratus or nimbostratus. 8 = Cumulus and stratocumulus...vibrous upper part by cumulus, stratocumulus, stratus or pannus . + . from Surface Marine Observations Tape Deck TDF-11 *Fog All clouds in the 0-50...Fractus of bad weather, cr V both ( pannus ), usually below Alto- stratus or N~imbostratus. The term "bad weather* denotes the conditions which coenerally

  8. Design of compact nuclear power marine engineering simulator

    International Nuclear Information System (INIS)

    Gao Jinghui; Xing Hongchuan; Zhang Ronghua; Yang Yanhua; Xu Jijun

    2004-01-01

    The essentiality of compact nuclear power marine engineering simulator (NPMES) is discussed. The technology of nuclear power plant engineering simulator (NPPES) for NPMES development is introduced, and the function design, general design and model design are given in details. A compact NPMES based on the nuclear power marine of 'Mutsu' is developed. The design can help the development of NPMES, which will improve operation safety and management efficiency of marine. (authors)

  9. A multi-year data set on aerosol-cloud-precipitation-meteorology interactions for marine stratocumulus clouds.

    Science.gov (United States)

    Sorooshian, Armin; MacDonald, Alexander B; Dadashazar, Hossein; Bates, Kelvin H; Coggon, Matthew M; Craven, Jill S; Crosbie, Ewan; Hersey, Scott P; Hodas, Natasha; Lin, Jack J; Negrón Marty, Arnaldo; Maudlin, Lindsay C; Metcalf, Andrew R; Murphy, Shane M; Padró, Luz T; Prabhakar, Gouri; Rissman, Tracey A; Shingler, Taylor; Varutbangkul, Varuntida; Wang, Zhen; Woods, Roy K; Chuang, Patrick Y; Nenes, Athanasios; Jonsson, Haflidi H; Flagan, Richard C; Seinfeld, John H

    2018-02-27

    Airborne measurements of meteorological, aerosol, and stratocumulus cloud properties have been harmonized from six field campaigns during July-August months between 2005 and 2016 off the California coast. A consistent set of core instruments was deployed on the Center for Interdisciplinary Remotely-Piloted Aircraft Studies Twin Otter for 113 flight days, amounting to 514 flight hours. A unique aspect of the compiled data set is detailed measurements of aerosol microphysical properties (size distribution, composition, bioaerosol detection, hygroscopicity, optical), cloud water composition, and different sampling inlets to distinguish between clear air aerosol, interstitial in-cloud aerosol, and droplet residual particles in cloud. Measurements and data analysis follow documented methods for quality assurance. The data set is suitable for studies associated with aerosol-cloud-precipitation-meteorology-radiation interactions, especially owing to sharp aerosol perturbations from ship traffic and biomass burning. The data set can be used for model initialization and synergistic application with meteorological models and remote sensing data to improve understanding of the very interactions that comprise the largest uncertainty in the effect of anthropogenic emissions on radiative forcing.

  10. Dependence of stratocumulus-topped boundary-layer entrainment on cloud-water sedimentation: Impact on global aerosol indirect effect in GISS ModelE3 single column model and global simulations

    Science.gov (United States)

    Ackerman, A. S.; Kelley, M.; Cheng, Y.; Fridlind, A. M.; Del Genio, A. D.; Bauer, S.

    2017-12-01

    Reduction in cloud-water sedimentation induced by increasing droplet concentrations has been shown in large-eddy simulations (LES) and direct numerical simulation (DNS) to enhance boundary-layer entrainment, thereby reducing cloud liquid water path and offsetting the Twomey effect when the overlying air is sufficiently dry, which is typical. Among recent upgrades to ModelE3, the latest version of the NASA Goddard Institute for Space Studies (GISS) general circulation model (GCM), are a two-moment stratiform cloud microphysics treatment with prognostic precipitation and a moist turbulence scheme that includes an option in its entrainment closure of a simple parameterization for the effect of cloud-water sedimentation. Single column model (SCM) simulations are compared to LES results for a stratocumulus case study and show that invoking the sedimentation-entrainment parameterization option indeed reduces the dependence of cloud liquid water path on increasing aerosol concentrations. Impacts of variations of the SCM configuration and the sedimentation-entrainment parameterization will be explored. Its impact on global aerosol indirect forcing in the framework of idealized atmospheric GCM simulations will also be assessed.

  11. Direct determination of radon in the marine troposphere

    International Nuclear Information System (INIS)

    Burtner, D.R.; Kay, J.G.

    1990-01-01

    222 Rn concentrations have been determined within and directly above the top of the marine boundary layer over the Eastern Pacific Ocean about 350 miles off the California coast. This was part of a multi-investigator, comprehensive study of the chemistry and dynamics of the marine stratocumulus conducted in July and August, 1985. Samples were collected using an aircraft, the Electra, in cooperation with National Center for Atmospheric Research. Concentrations of radon, determined by the Lucas cell method using charcoal absorption techniques, ranged from a low of about 12 atoms of radon per liter of air to a high of about 430 atoms/l. Entrainment rates across the top of the marine boundary layer have been determined from these measurements. Correlation of radon concentrations with other chemical species is suggested in certain cases

  12. On the relevance of droplet sedimentation in stratocumulus-top mixing

    Science.gov (United States)

    Mellado, Juan Pedro; de Lozar, Alberto

    2017-11-01

    The interaction between droplet sedimentation, turbulent mixing, evaporative cooling, and radiative cooling at the top of stratocumulus clouds has been studied using direct numerical simulations. This interaction is important to determine the mixing rate of the cloud and dry air above it, which eventually determines the cloud lifetime. By investigating the entrainment-rate equation, which is an analytical relationship between the contributions to cloud-top entrainment from the phenomena indicated above, we have found that the reduction of entrainment velocity by droplet sedimentation can be 2 to 3 times larger than previously conjectured. The reason is twofold. First, the reduction of evaporative cooling as droplets fall out of the inversion is stronger than previously observed in large-eddy simulations, where excessive mixing by turbulence models and numerical artifacts may have partially masked this effect of sedimentation on entrainment. Second, there is a non-negligible direct contribution from mass loading, as falling droplets leave behind more buoyant air in the inversion. This contribution is proportional to the fifth moment of the droplet-size distribution, which provides further evidence for the need to better understand the evolution of the droplet-size distribution.

  13. The development of fast simulation program for marine reactor parameters

    International Nuclear Information System (INIS)

    Chen Zhiyun; Hao Jianli; Chen Wenzhen

    2012-01-01

    Highlights: ► The simplified physical and mathematical models are proposed for a marine reactor system. ► A program is developed with Simulink module and Matlab file. ► The program developed has the merit of easy input preparation, output processing and fast running. ► The program can be used for the fast simulation of marine reactor parameters on the operating field. - Abstract: The fast simulation program for marine reactor parameters is developed based on the Simulink simulating software according to the characteristics of marine reactor with requirement of maneuverability and acute and fast response. The simplified core physical and thermal model, pressurizer model, steam generator model, control rod model, reactivity model and the corresponding Simulink modules are established. The whole program is developed by coupling all the Simulink modules. Two typical transient processes of marine reactor with fast load increase at low power level and load rejection at high power level are adopted to verify the program. The results are compared with those of Relap5/Mod3.2 with good consistency, and the program runs very fast. It is shown that the program is correct and suitable for the fast and accurate simulation of marine reactor parameters on the operating field, which is significant to the marine reactor safe operation.

  14. Network approach to patterns in stratocumulus clouds

    Science.gov (United States)

    Glassmeier, Franziska; Feingold, Graham

    2017-10-01

    Stratocumulus clouds (Sc) have a significant impact on the amount of sunlight reflected back to space, with important implications for Earth’s climate. Representing Sc and their radiative impact is one of the largest challenges for global climate models. Sc fields self-organize into cellular patterns and thus lend themselves to analysis and quantification in terms of natural cellular networks. Based on large-eddy simulations of Sc fields, we present a first analysis of the geometric structure and self-organization of Sc patterns from this network perspective. Our network analysis shows that the Sc pattern is scale-invariant as a consequence of entropy maximization that is known as Lewis’s Law (scaling parameter: 0.16) and is largely independent of the Sc regime (cloud-free vs. cloudy cell centers). Cells are, on average, hexagonal with a neighbor number variance of about 2, and larger cells tend to be surrounded by smaller cells, as described by an Aboav-Weaire parameter of 0.9. The network structure is neither completely random nor characteristic of natural convection. Instead, it emerges from Sc-specific versions of cell division and cell merging that are shaped by cell expansion. This is shown with a heuristic model of network dynamics that incorporates our physical understanding of cloud processes.

  15. Scientific Visualization and Simulation for Multi-dimensional Marine Environment Data

    Science.gov (United States)

    Su, T.; Liu, H.; Wang, W.; Song, Z.; Jia, Z.

    2017-12-01

    As higher attention on the ocean and rapid development of marine detection, there are increasingly demands for realistic simulation and interactive visualization of marine environment in real time. Based on advanced technology such as GPU rendering, CUDA parallel computing and rapid grid oriented strategy, a series of efficient and high-quality visualization methods, which can deal with large-scale and multi-dimensional marine data in different environmental circumstances, has been proposed in this paper. Firstly, a high-quality seawater simulation is realized by FFT algorithm, bump mapping and texture animation technology. Secondly, large-scale multi-dimensional marine hydrological environmental data is virtualized by 3d interactive technologies and volume rendering techniques. Thirdly, seabed terrain data is simulated with improved Delaunay algorithm, surface reconstruction algorithm, dynamic LOD algorithm and GPU programming techniques. Fourthly, seamless modelling in real time for both ocean and land based on digital globe is achieved by the WebGL technique to meet the requirement of web-based application. The experiments suggest that these methods can not only have a satisfying marine environment simulation effect, but also meet the rendering requirements of global multi-dimension marine data. Additionally, a simulation system for underwater oil spill is established by OSG 3D-rendering engine. It is integrated with the marine visualization method mentioned above, which shows movement processes, physical parameters, current velocity and direction for different types of deep water oil spill particle (oil spill particles, hydrates particles, gas particles, etc.) dynamically and simultaneously in multi-dimension. With such application, valuable reference and decision-making information can be provided for understanding the progress of oil spill in deep water, which is helpful for ocean disaster forecasting, warning and emergency response.

  16. Marine cloud brightening: regional applications.

    Science.gov (United States)

    Latham, John; Gadian, Alan; Fournier, Jim; Parkes, Ben; Wadhams, Peter; Chen, Jack

    2014-12-28

    The general principle behind the marine cloud brightening (MCB) climate engineering technique is that seeding marine stratocumulus clouds with substantial concentrations of roughly monodisperse sub-micrometre-sized seawater particles might significantly enhance cloud albedo and longevity, thereby producing a cooling effect. This paper is concerned with preliminary studies of the possible beneficial application of MCB to three regional issues: (1) recovery of polar ice loss, (2) weakening of developing hurricanes and (3) elimination or reduction of coral bleaching. The primary focus is on Item 1. We focus discussion herein on advantages associated with engaging in limited-area seeding, regional effects rather than global; and the levels of seeding that may be required to address changing current and near-term conditions in the Arctic. We also mention the possibility that MCB might be capable of producing a localized cooling to help stabilize the West Antarctic Ice Sheet.

  17. Simulating Fine-Scale Marine Pollution Plumes for Autonomous Robotic Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    Muhammad Fahad

    2018-05-01

    Full Text Available Marine plumes exhibit characteristics such as intermittency, sinuous structure, shape and flow field coherency, and a time varying concentration profile. Due to the lack of experimental quantification of these characteristics for marine plumes, existing work often assumes marine plumes exhibit behavior similar to aerial plumes and are commonly modeled by filament based Lagrangian models. Our previous field experiments with Rhodamine dye plumes at Makai Research Pier at Oahu, Hawaii revealed that marine plumes show similar characteristics to aerial plumes qualitatively, but quantitatively they are disparate. Based on the field data collected, this paper presents a calibrated Eulerian plume model that exhibits the qualitative and quantitative characteristics exhibited by experimentally generated marine plumes. We propose a modified model with an intermittent source, and implement it in a Robot Operating System (ROS based simulator. Concentration time series of stationary sampling points and dynamic sampling points across cross-sections and plume fronts are collected and analyzed for statistical parameters of the simulated plume. These parameters are then compared with statistical parameters from experimentally generated plumes. The comparison validates that the simulated plumes exhibit fine-scale qualitative and quantitative characteristics similar to experimental plumes. The ROS plume simulator facilitates future evaluations of environmental monitoring strategies by marine robots, and is made available for community use.

  18. A Mixed-Layer Model perspective on stratocumulus steady-states in a perturbed climate

    NARCIS (Netherlands)

    Dal Gesso, S.; Siebesma, A.P.; de Roode, S.R.; van Wessem, J.M.

    2013-01-01

    Equilibrium states of stratocumulus are evaluated for a range of free tropospheric conditions in a Mixed-Layer Model framework using a number of different entrainment formulations. The equilibrium states show that a reduced lower tropospheric stability (LTS) and a dryer free troposphere support a

  19. Multimode marine engine room simulation system based on field bus technology

    Science.gov (United States)

    Zheng, Huayao; Deng, Linlin; Guo, Yi

    2003-09-01

    Developing multi mode MER (Marine Engine Room) Labs is the main work in Marine Simulation Center, which is the key lab of Communication Ministry of China. It includes FPP (Fixed Pitch Propeller) and CPP (Controllable Pitch Propeller) mode MER simulation systems, integrated electrical propulsion mode MER simulation system, physical mode MER lab, etc. FPP mode simulation system, which was oriented to large container ship, had been completed since 1999, and got second level of Shanghai Municipal Science and Technical Progress award. This paper mainly introduces the recent development and achievements of Marine Simulation Center. Based on the Lon Works field bus, the structure characteristics and control strategies of completely distributed intelligent control network are discussed. The experiment mode of multi-nodes field bus detection and control system is described. Besides, intelligent fault diagnosis technology about some mechatronics integration control systems explored is also involved.

  20. Contrasting Cloud Composition Between Coupled and Decoupled Marine Boundary Layer Clouds

    Science.gov (United States)

    WANG, Z.; Mora, M.; Dadashazar, H.; MacDonald, A.; Crosbie, E.; Bates, K. H.; Coggon, M. M.; Craven, J. S.; Xian, P.; Campbell, J. R.; AzadiAghdam, M.; Woods, R. K.; Jonsson, H.; Flagan, R. C.; Seinfeld, J.; Sorooshian, A.

    2016-12-01

    Marine stratocumulus clouds often become decoupled from the vertical layer immediately above the ocean surface. This study contrasts cloud chemical composition between coupled and decoupled marine stratocumulus clouds. Cloud water and droplet residual particle composition were measured in clouds off the California coast during three airborne experiments in July-August of separate years (E-PEACE 2011, NiCE 2013, BOAS 2015). Decoupled clouds exhibited significantly lower overall mass concentrations in both cloud water and droplet residual particles, consistent with reduced cloud droplet number concentration and sub-cloud aerosol (Dp > 100 nm) number concentration, owing to detachment from surface sources. Non-refractory sub-micrometer aerosol measurements show that coupled clouds exhibit higher sulfate mass fractions in droplet residual particles, owing to more abundant precursor emissions from the ocean and ships. Consequently, decoupled clouds exhibited higher mass fractions of organics, nitrate, and ammonium in droplet residual particles, owing to effects of long-range transport from more distant sources. Total cloud water mass concentration in coupled clouds was dominated by sodium and chloride, and their mass fractions and concentrations exceeded those in decoupled clouds. Conversely, with the exception of sea salt constituents (e.g., Cl, Na, Mg, K), cloud water mass fractions of all species examined were higher in decoupled clouds relative to coupled clouds. These results suggest that an important variable is the extent to which clouds are coupled to the surface layer when interpreting microphysical data relevant to clouds and aerosol particles.

  1. Impacts of aerosol particles on the microphysical and radiative properties of stratocumulus clouds over the southeast Pacific Ocean

    Directory of Open Access Journals (Sweden)

    C. H. Twohy

    2013-03-01

    Full Text Available The southeast Pacific Ocean is covered by the world's largest stratocumulus cloud layer, which has a strong impact on ocean temperatures and climate in the region. The effect of anthropogenic sources of aerosol particles on the stratocumulus deck was investigated during the VOCALS field experiment. Aerosol measurements below and above cloud were made with a ultra-high sensitivity aerosol spectrometer and analytical electron microscopy. In addition to more standard in-cloud measurements, droplets were collected and evaporated using a counterflow virtual impactor (CVI, and the non-volatile residual particles were analyzed. Many flights focused on the gradient in cloud properties on an E-W track along 20° S from near the Chilean coast to remote areas offshore. Mean statistics, including their significance, from eight flights and many individual legs were compiled. Consistent with a continental source of cloud condensation nuclei, below-cloud accumulation-mode aerosol and droplet number concentration generally decreased from near shore to offshore. Single particle analysis was used to reveal types and sources of the enhanced particle number that influence droplet concentration. While a variety of particle types were found throughout the region, the dominant particles near shore were partially neutralized sulfates. Modeling and chemical analysis indicated that the predominant source of these particles in the marine boundary layer along 20° S was anthropogenic pollution from central Chilean sources, with copper smelters a relatively small contribution. Cloud droplets were smaller in regions of enhanced particles near shore. However, physically thinner clouds, and not just higher droplet number concentrations from pollution, both contributed to the smaller droplets. Satellite measurements were used to show that cloud albedo was highest 500–1000 km offshore, and actually slightly lower closer to shore due to the generally thinner clouds and lower

  2. Modified ultrafast thermometer UFT-M and temperature measurements during Physics of Stratocumulus Top (POST

    Directory of Open Access Journals (Sweden)

    W. Kumala

    2013-08-01

    Full Text Available A modified UFT-M version of the ultrafast airborne thermometer UFT, aimed at in-cloud temperature measurements, was designed for the Physics of Stratocumulus Top (POST field campaign. Improvements in its construction resulted in the sensor's increased reliability, which provided valuable measurements in 15 of the 17 flights. Oversampling the data allowed for the effective correction of the artefacts resulting from the interference with electromagnetic transmissions from on-board avionic systems and the thermal noise resulting from the sensor construction. The UFT-M records, when averaged to the 1.4 and 55 m resolutions, compared to the similar records of a thermometer in a Rosemount housing, indicate that the housing distorts even low-resolution airborne temperature measurements. Data collected with the UFT-M during the course of POST characterise the thermal structure of stratocumulus and capping inversion with the maximum resolution of ~1 cm. In this paper, examples of UFT-M records are presented and discussed.

  3. A single-column model intercomparison on the stratocumulus representation in present-day and future climate

    NARCIS (Netherlands)

    Dal Gesso, S.; Van der Dussen, J.J.; Siebesma, A.P.; De Roode, S.R.; Boutle, I.A.; Kamae, Y.; Roehrig, R.; Vial, J.

    2015-01-01

    Six Single-Column Model (SCM) versions of climate models are evaluated on the basis of their representation of the dependence of the stratocumulus-topped boundary layer regime on the free tropospheric thermodynamic conditions. The study includes two idealized experiments corresponding to the

  4. Mathematical model of marine diesel engine simulator for a new methodology of self propulsion tests

    Energy Technology Data Exchange (ETDEWEB)

    Izzuddin, Nur; Sunarsih,; Priyanto, Agoes [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2015-05-15

    As a vessel operates in the open seas, a marine diesel engine simulator whose engine rotation is controlled to transmit through propeller shaft is a new methodology for the self propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through a computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the target vessel’s speed. The input and output are a real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion tests in calm waters were conducted using a vessel model to validate the marine diesel engine simulator. The simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbochargers for the marine diesel engine simulator. The control system developed will be beneficial for users as to analyze different condition of vessel’s speed to obtain better characteristics and hence optimize the fuel saving rate.

  5. Modelling microphysical and meteorological controls on precipitation and cloud cellular structures in Southeast Pacific stratocumulus

    Directory of Open Access Journals (Sweden)

    H. Wang

    2010-07-01

    Full Text Available Microphysical and meteorological controls on the formation of open and closed cellular structures in the Southeast Pacific are explored using model simulations based on aircraft observations during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx. The effectiveness of factors such as boundary-layer moisture and temperature perturbations, surface heat and moisture fluxes, large-scale vertical motion and solar heating in promoting drizzle and open cell formation for prescribed aerosol number concentrations is explored. For the case considered, drizzle and subsequent open cell formation over a broad region are more sensitive to the observed boundary-layer moisture and temperature perturbations (+0.9 g kg−1; −1 K than to a five-fold decrease in aerosol number concentration (150 vs. 30 mg−1. When embedding the perturbations in closed cells, local drizzle and pockets of open cell (POC formation respond faster to the aerosol reduction than to the moisture increase, but the latter generates stronger and more persistent drizzle. A local negative perturbation in temperature drives a mesoscale circulation that prevents local drizzle formation but promotes it in a remote area where lower-level horizontal transport of moisture is blocked and converges to enhance liquid water path. This represents a potential mechanism for POC formation in the Southeast Pacific stratocumulus region whereby the circulation is triggered by strong precipitation in adjacent broad regions of open cells. A simulation that attempts to mimic the influence of a coastally induced upsidence wave results in an increase in cloud water but this alone is insufficient to initiate drizzle. An increase of surface sensible heat flux is also effective in triggering local drizzle and POC formation.

    Both open and closed cells simulated with observed initial conditions exhibit distinct diurnal variations in cloud properties. A

  6. A mixed-layer model study of the stratocumulus response to changes in large-scale conditions

    NARCIS (Netherlands)

    De Roode, S.R.; Siebesma, A.P.; Dal Gesso, S.; Jonker, H.J.J.; Schalkwijk, J.; Sival, J.

    2014-01-01

    A mixed-layer model is used to study the response of stratocumulus equilibrium state solutions to perturbations of cloud controlling factors which include the sea surface temperature, the specific humidity and temperature in the free troposphere, as well as the large-scale divergence and horizontal

  7. Effects of stratocumulus, cumulus, and cirrus clouds on the UV-B diffuse to global ratio: Experimental and modeling results

    International Nuclear Information System (INIS)

    López, María Laura; Palancar, Gustavo G.; Toselli, Beatriz M.

    2012-01-01

    Broadband measurements of global and diffuse UV-B irradiance (280-315 nm) together with modeled and measured diffuse to global ratios (DGR) have been used to characterize the influence of different types of clouds on irradiance at the surface. Measurements were carried out during 2000-2001 in Córdoba City, Argentina. The Tropospheric Ultraviolet Visible (TUV) model was used to analyze the behavior of the modeled DGRs for different cloud optical depths and at different altitudes and solar zenith angles (SZA). Different cloud altitudes were also tested, although only the results for a cloud placed at 1.5-2.5 km of altitude are shown. A total of 16 day with stratocumulus, 12 with cumulus, and 16 with cirrus have been studied and compared among them and also against 21 clear sky days. Different behaviors were clearly detected and also differentiated through the analysis of the averages and the standard deviations of the DGRs: 1.02±0.06 for stratocumulus, 0.74±0.18 for cumulus, 0.63±0.12 for cirrus, and 0.60±0.13 for the clear sky days, respectively. Stratocumulus clouds showed a low variability in the DGR values, which were concentrated close to one at all SZAs. DGR values for cumulus clouds presented a large variability at all SZAs, mostly associated with the different optical depths. Finally, the closeness between the DGR values for cirrus clouds and the DGR values for clear days showed that these clouds generally do not strongly affect the UV-B irradiance at the surface at any SZA. In the opposite side, stratocumulus clouds were identified as those with the largest effects, at all SZAs, on the UV-B irradiance at the surface.

  8. Design of Simulink module for dynamic reactivity simulation of marine reactor automatic control rod

    International Nuclear Information System (INIS)

    Chen Zhiyun; Luo Lei; Chen Wenzhen; Gui Xuewen

    2010-01-01

    The power of marine reactor varies frequently and acutely, which induces the frequent and acute adjustment of the automatic control rod. According to the characteristics of marine reactor and the problem of improper control rod reactivity insertion in previous literatures, the Simulink module for dynamic reactivity simulation of automatic control rod was designed and adopted as a sub-module of Simulink program for the fast calculation of the physical and thermal parameters of marine reactor. A typical dynamic process of the marine reactor was used as the benchmark, which indicates that the designed Simulink module is capable of the dynamic simulation of automatic control rod position and reactivity, and is adequate to the fast calculation of physic and thermal parameters. The Simulink module is of significant meaning to the simulation of the dynamic process of marine reactor and the fast calculation of the operating parameters. (authors)

  9. Dynamics, thermodynamics, radiation, and cloudiness associated with cumulus-topped marine boundary layers

    Energy Technology Data Exchange (ETDEWEB)

    Ghate, Virendra P. [Argonne National Lab. (ANL), Argonne, IL (United States); Miller, Mark [Rutgers Univ., New Brunswick, NJ (United States)

    2016-11-01

    The overall goal of this project was to improve the understanding of marine boundary clouds by using data collected at the Atmospheric Radiation Measurement (ARM) sites, so that they can be better represented in global climate models (GCMs). Marine boundary clouds are observed regularly over the tropical and subtropical oceans. They are an important element of the Earth’s climate system because they have substantial impact on the radiation budget together with the boundary layer moisture, and energy transports. These clouds also have an impact on large-scale precipitation features like the Inter Tropical Convergence Zone (ITCZ). Because these clouds occur at temporal and spatial scales much smaller than those relevant to GCMs, their effects and the associated processes need to be parameterized in GCM simulations aimed at predicting future climate and energy needs. Specifically, this project’s objectives were to (1) characterize the surface turbulent fluxes, boundary layer thermodynamics, radiation field, and cloudiness associated with cumulus-topped marine boundary layers; (2) explore the similarities and differences in cloudiness and boundary layer conditions observed in the tropical and trade-wind regions; and (3) understand similarities and differences by using a simple bulk boundary layer model. In addition to working toward achieving the project’s three objectives, we also worked on understanding the role played by different forcing mechanisms in maintaining turbulence within cloud-topped boundary layers We focused our research on stratocumulus clouds during the first phase of the project, and cumulus clouds during the rest of the project. Below is a brief description of manuscripts published in peer-reviewed journals that describe results from our analyses.

  10. Energy Yield Potential Estimation Using Marine Current Turbine Simulations for the Bosphorus

    DEFF Research Database (Denmark)

    Yazicioglu, Hasan; Tunc, K. M. Murat; Ozbek, Muammer

    2017-01-01

    . The differences in elevation and salinity ratios between these two seas cause strong underwater currents. Depending on the morphology of the canal the speed of the flow varies and at some specific locations the energy intensity reaches to sufficient levels where electricity generation by marine current turbines...... becomes economically feasible. In this study, several simulations are performed for a 10 MW marine turbine farm/ cluster whose location is selected by taking into account several factors such as the canal morphology, current speed and passage of vessels. 360 different simulations are performed for 15...... within the selected region, the analyses are performed for three different flow speeds corresponding to 10 % increase and decrease in the average value. For each simulation the annual energy yield and cluster efficiency are calculated....

  11. An A-train and MERRA view of cloud, thermodynamic, and dynamic variability within the subtropical marine boundary layer

    Directory of Open Access Journals (Sweden)

    B. H. Kahn

    2017-08-01

    Full Text Available The global-scale patterns and covariances of subtropical marine boundary layer (MBL cloud fraction and spatial variability with atmospheric thermodynamic and dynamic fields remain poorly understood. We describe an approach that leverages coincident NASA A-train and the Modern Era Retrospective-Analysis for Research and Applications (MERRA data to quantify the relationships in the subtropical MBL derived at the native pixel and grid resolution. A new method for observing four subtropical oceanic regions that capture transitions from stratocumulus to trade cumulus is demonstrated, where stratocumulus and cumulus regimes are determined from infrared-based thermodynamic phase. Visible radiances are normally distributed within stratocumulus and are increasingly skewed away from the coast, where trade cumulus dominates. Increases in MBL depth, wind speed, and effective radius (re, and reductions in 700–1000 hPa moist static energy differences and 700 and 850 hPa vertical velocity correspond with increases in visible radiance skewness. We posit that a more robust representation of the cloudy MBL is obtained using visible radiance rather than retrievals of optical thickness that are limited to a smaller subset of cumulus. The method using the combined A-train and MERRA data set has demonstrated that an increase in re within shallow cumulus is strongly related to higher MBL wind speeds that further correspond to increased precipitation occurrence according to CloudSat, previously demonstrated with surface observations. Hence, the combined data sets have the potential of adding global context to process-level understanding of the MBL.

  12. Simulation of low clouds in the Southeast Pacific by the NCEP GFS: sensitivity to vertical mixing

    Science.gov (United States)

    Sun, R.; Moorthi, S.; Xiao, H.; Mechoso, C. R.

    2010-12-01

    The NCEP Global Forecast System (GFS) model has an important systematic error shared by many other models: stratocumuli are missed over the subtropical eastern oceans. It is shown that this error can be alleviated in the GFS by introducing a consideration of the low-level inversion and making two modifications in the model's representation of vertical mixing. The modifications consist of (a) the elimination of background vertical diffusion above the inversion and (b) the incorporation of a stability parameter based on the cloud-top entrainment instability (CTEI) criterion, which limits the strength of shallow convective mixing across the inversion. A control simulation and three experiments are performed in order to examine both the individual and combined effects of modifications on the generation of the stratocumulus clouds. Individually, both modifications result in enhanced cloudiness in the Southeast Pacific (SEP) region, although the cloudiness is still low compared to the ISCCP climatology. If the modifications are applied together, however, the total cloudiness produced in the southeast Pacific has realistic values. This nonlinearity arises as the effects of both modifications reinforce each other in reducing the leakage of moisture across the inversion. Increased moisture trapped below the inversion than in the control run without modifications leads to an increase in cloud amount and cloud-top radiative cooling. Then a positive feedback due to enhanced turbulent mixing in the planetary boundary layer by cloud-top radiative cooling leads to and maintains the stratocumulus cover. Although the amount of total cloudiness obtained with both modifications has realistic values, the relative contributions of low, middle, and high layers tend to differ from the observations. These results demonstrate that it is possible to simulate realistic marine boundary clouds in large-scale models by implementing direct and physically based improvements in the model

  13. Simulation of air pollution due to marine engines

    Science.gov (United States)

    Stan, L. C.

    2017-08-01

    This paperwork tried to simulate the combustion inside the marine engines using the newest computer methods and technologies with the result of a diverse and rich palette of solutions, extremely useful for the study and prediction of complex phenomena of the fuel combustion. The paperwork is contributing to the theoretical systematization of the area of interest bringing into attention a thoroughly inventory of the thermodynamic description of the phenomena which take place in the combustion process into the marine diesel engines; to the in depth multidimensional combustion models description along with the interdisciplinary phenomenology taking place in the combustion models; to the FEA (Finite Elements Method) modelling for the combustion chemistry in the nonpremixed mixtures approach considered too; the CFD (Computational Fluid Dynamics) model was issued for the combustion area and a rich palette of results interesting for any researcher of the process.

  14. Cavitation simulation on marine propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo

    Cavitation on marine propellers causes thrust breakdown, noise, vibration and erosion. The increasing demand for high-efficiency propellers makes it difficult to avoid the occurrence of cavitation. Currently, practical analysis of propeller cavitation depends on cavitation tunnel test, empirical...... criteria and inviscid flow method, but a series of model test is costly and the other two methods have low accuracy. Nowadays, computational fluid dynamics by using a viscous flow solver is common for practical industrial applications in many disciplines. Cavitation models in viscous flow solvers have been...... hydrofoils and conventional/highly-skewed propellers are performed with one of three cavitation models proven in 2D analysis. 3D cases also show accuracy and robustness of numerical method in simulating steady and unsteady sheet cavitation on complicated geometries. Hydrodynamic characteristics of cavitation...

  15. Hybrid Method Simulation of Slender Marine Structures

    DEFF Research Database (Denmark)

    Christiansen, Niels Hørbye

    This present thesis consists of an extended summary and five appended papers concerning various aspects of the implementation of a hybrid method which combines classical simulation methods and artificial neural networks. The thesis covers three main topics. Common for all these topics...... only recognize patterns similar to those comprised in the data used to train the network. Fatigue life evaluation of marine structures often considers simulations of more than a hundred different sea states. Hence, in order for this method to be useful, the training data must be arranged so...... that a single neural network can cover all relevant sea states. The applicability and performance of the present hybrid method is demonstrated on a numerical model of a mooring line attached to a floating offshore platform. The second part of the thesis demonstrates how sequential neural networks can be used...

  16. Atmospheric System Research Marine Low Clouds Workshop Report, January 27-29,2016

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, M. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Wang, J. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Wood, R. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2016-06-01

    Marine low clouds are a major determinant of the Earth?s albedo and are a major source of uncertainty in how the climate responds to changing greenhouse gas levels and anthropogenic aerosol. Marine low clouds are particularly difficult to simulate accurately in climate models, and their remote locations present a significant observational challenge. A complex set of interacting controlling processes determine the coverage, condensate loading, and microphysical and radiative properties of marine low clouds. Marine low clouds are sensitive to atmospheric aerosol in several ways. Interactions at microphysical scales involve changes in the concentration of cloud droplets and precipitation, which induce cloud dynamical impacts including changes in entrainment and mesoscale organization. Marine low clouds are also impacted by atmospheric heating changes due to absorbing aerosols. The response of marine low clouds to aerosol perturbations depends strongly upon the unperturbed aerosol-cloud state, which necessitates greater understanding of processes controlling the budget of aerosol in the marine boundary layer. Entrainment and precipitation mediate the response of low clouds to aerosols but these processes also play leading roles in controlling the aerosol budget. The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility and Atmospheric System Research (ASR) program are making major recent investments in observational data sets from fixed and mobile sites dominated by marine low clouds. This report provides specific action items for how these measurements can be used together with process modeling to make progress on understanding and quantifying the key cloud and aerosol controlling processes in the next 5-10 years. Measurements of aerosol composition and its variation with particle size are needed to advance a quantitative, process-level understanding of marine boundary-layer aerosol budget. Quantitative precipitation estimates

  17. An Evaluation of Marine Boundary Layer Cloud Property Simulations in the Community Atmosphere Model Using Satellite Observations: Conventional Subgrid Parameterization versus CLUBB

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hua [Joint Center for Earth Systems Technology, University of Maryland, Baltimore County, Baltimore, Maryland; Zhang, Zhibo [Joint Center for Earth Systems Technology, and Physics Department, University of Maryland, Baltimore County, Baltimore, Maryland; Ma, Po-Lun [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Ghan, Steven J. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Wang, Minghuai [Institute for Climate and Global Change Research, and School of Atmospheric Sciences, Nanjing University, Nanjing, China

    2018-03-01

    This paper presents a two-step evaluation of the marine boundary layer (MBL) cloud properties from two Community Atmospheric Model (version 5.3, CAM5) simulations, one based on the CAM5 standard parameterization schemes (CAM5-Base), and the other on the Cloud Layers Unified By Binormals (CLUBB) scheme (CAM5-CLUBB). In the first step, we compare the cloud properties directly from model outputs between the two simulations. We find that the CAM5-CLUBB run produces more MBL clouds in the tropical and subtropical large-scale descending regions. Moreover, the stratocumulus (Sc) to cumulus (Cu) cloud regime transition is much smoother in CAM5-CLUBB than in CAM5-Base. In addition, in CAM5-Base we find some grid cells with very small low cloud fraction (<20%) to have very high in-cloud water content (mixing ratio up to 400mg/kg). We find no such grid cells in the CAM5-CLUBB run. However, we also note that both simulations, especially CAM5-CLUBB, produce a significant amount of “empty” low cloud cells with significant cloud fraction (up to 70%) and near-zero in-cloud water content. In the second step, we use satellite observations from CERES, MODIS and CloudSat to evaluate the simulated MBL cloud properties by employing the COSP satellite simulators. We note that a feature of the COSP-MODIS simulator to mimic the minimum detection threshold of MODIS cloud masking removes much more low clouds from CAM5-CLUBB than it does from CAM5-Base. This leads to a surprising result — in the large-scale descending regions CAM5-CLUBB has a smaller COSP-MODIS cloud fraction and weaker shortwave cloud radiative forcing than CAM5-Base. A sensitivity study suggests that this is because CAM5-CLUBB suffers more from the above-mentioned “empty” clouds issue than CAM5-Base. The COSP-MODIS cloud droplet effective radius in CAM5-CLUBB shows a spatial increase from coastal St toward Cu, which is in qualitative agreement with MODIS observations. In contrast, COSP-MODIS cloud droplet

  18. How thermodynamic environments control stratocumulus microphysics and interactions with aerosols

    International Nuclear Information System (INIS)

    Andersen, Hendrik; Cermak, Jan

    2015-01-01

    Aerosol–cloud interactions are central to climate system changes and depend on meteorological conditions. This study identifies distinct thermodynamic regimes and proposes a conceptual framework for interpreting aerosol effects. In the analysis, ten years (2003–2012) of daily satellite-derived aerosol and cloud products are combined with reanalysis data to identify factors controlling Southeast Atlantic stratocumulus microphysics. Considering the seasonal influence of aerosol input from biomass burning, thermodynamic environments that feature contrasting microphysical cloud properties and aerosol–cloud relations are classified. While aerosol impact is stronger in unstable environments, it is mostly confined to situations with low aerosol loading (aerosol index AI ≲ 0.15), implying a saturation of aerosol effects. Situations with high aerosol loading are associated with weaker, seasonally contrasting aerosol-droplet size relationships, likely caused by thermodynamically induced processes and aerosol swelling. (letter)

  19. Moisture and dynamical interactions maintaining decoupled Arctic mixed-phase stratocumulus in the presence of a humidity inversion

    Directory of Open Access Journals (Sweden)

    A. Solomon

    2011-10-01

    Full Text Available Observations suggest that processes maintaining subtropical and Arctic stratocumulus differ, due to the different environments in which they occur. For example, specific humidity inversions (specific humidity increasing with height are frequently observed to occur near cloud top coincident with temperature inversions in the Arctic, while they do not occur in the subtropics. In this study we use nested LES simulations of decoupled Arctic Mixed-Phase Stratocumulus (AMPS clouds observed during the DOE Atmospheric Radiation Measurement Program's Indirect and SemiDirect Aerosol Campaign (ISDAC to analyze budgets of water components, potential temperature, and turbulent kinetic energy. These analyses quantify the processes that maintain decoupled AMPS, including the role of humidity inversions. Key structural features include a shallow upper entrainment zone at cloud top that is located within the temperature and humidity inversions, a mixed layer driven by cloud-top cooling that extends from the base of the upper entrainment zone to below cloud base, and a lower entrainment zone at the base of the mixed layer. The surface layer below the lower entrainment zone is decoupled from the cloud mixed-layer system. Budget results show that cloud liquid water is maintained in the upper entrainment zone near cloud top (within a temperature and humidity inversion due to a down gradient transport of water vapor by turbulent fluxes into the cloud layer from above and direct condensation forced by radiative cooling. Liquid water is generated in the updraft portions of the mixed-layer eddies below cloud top by buoyant destabilization. These processes cause at least 20% of the cloud liquid water to extend into the inversion. The redistribution of water vapor from the top of the humidity inversion to its base maintains the cloud layer, while the mixed layer-entrainment zone system is continually losing total water. In this decoupled system, the humidity inversion is

  20. Collaborative Research: Cloudiness transitions within shallow marine clouds near the Azores

    Energy Technology Data Exchange (ETDEWEB)

    Mechem, David B. [Univ. of Kansas, Lawrence, KS (United States). Atmospheric Science Program. Dept. of Geography and Atmospheric Science; de Szoeke, Simon P. [Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Sciences; Yuter, Sandra E. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Marine, Earth, and Atmospheric Sciences

    2017-01-15

    Marine stratocumulus clouds are low, persistent, liquid phase clouds that cover large areas and play a significant role in moderating the climate by reflecting large quantities of incoming solar radiation. The deficiencies in simulating these clouds in global climate models are widely recognized. Much of the uncertainty arises from sub-grid scale variability in the cloud albedo that is not accurately parameterized in climate models. The Clouds, Aerosol and Precipitation in the Marine Boundary Layer (CAP–MBL) observational campaign and the ongoing ARM site measurements on Graciosa Island in the Azores aim to sample the Northeast Atlantic low cloud regime. These data represent, the longest continuous research quality cloud radar/lidar/radiometer/aerosol data set of open-ocean shallow marine clouds in existence. Data coverage from CAP–MBL and the series of cruises to the southeast Pacific culminating in VOCALS will both be of sufficient length to contrast the two low cloud regimes and explore the joint variability of clouds in response to several environmental factors implicated in cloudiness transitions. Our research seeks to better understand cloud system processes in an underexplored but climatologically important maritime region. Our primary goal is an improved physical understanding of low marine clouds on temporal scales of hours to days. It is well understood that aerosols, synoptic-scale forcing, surface fluxes, mesoscale dynamics, and cloud microphysics all play a role in cloudiness transitions. However, the relative importance of each mechanism as a function of different environmental conditions is unknown. To better understand cloud forcing and response, we are documenting the joint variability of observed environmental factors and associated cloud characteristics. In order to narrow the realm of likely parameter ranges, we assess the relative importance of parameter conditions based primarily on two criteria: how often the condition occurs (frequency

  1. Development and validation of a new turbocharger simulation methodology for marine two stroke diesel engine modelling and diagnostic applications

    International Nuclear Information System (INIS)

    Sakellaridis, Nikolaos F.; Raptotasios, Spyridon I.; Antonopoulos, Antonis K.; Mavropoulos, Georgios C.; Hountalas, Dimitrios T.

    2015-01-01

    Engine cycle simulation models are increasingly used in diesel engine simulation and diagnostic applications, reducing experimental effort. Turbocharger simulation plays an important role in model's ability to accurately predict engine performance and emissions. The present work describes the development of a complete engine simulation model for marine Diesel engines based on a new methodology for turbocharger modelling utilizing physically based meanline models for compressor and turbine. Simulation accuracy is evaluated against engine bench measurements. The methodology was developed to overcome the problem of limited experimental maps availability for compressor and turbine, often encountered in large marine diesel engine simulation and diagnostic studies. Data from the engine bench are used to calibrate the models, as well as to estimate turbocharger shaft mechanical efficiency. Closed cycle and gas exchange are modelled using an existing multizone thermodynamic model. The proposed methodology is applied on a 2-stroke marine diesel engine and its evaluation is based on the comparison of predictions against measured engine data. It is demonstrated model's ability to predict engine response with load variation regarding both turbocharger performance and closed cycle parameters, as well as NOx emission trends, making it an effective tool for both engine diagnostic and optimization studies. - Highlights: • Marine two stroke diesel engine simulation model. • Turbine and compressor simulation using physical meanline models. • Methodology to derive T/C component efficiency and T/C shaft mechanical efficiency. • Extensive validation of predictions against experimental data.

  2. Aerosol characteristics in the entrainment interface layer in relation to the marine boundary layer and free troposphere

    Directory of Open Access Journals (Sweden)

    H. Dadashazar

    2018-02-01

    Full Text Available This study uses airborne data from two field campaigns off the California coast to characterize aerosol size distribution characteristics in the entrainment interface layer (EIL, a thin and turbulent layer above marine stratocumulus cloud tops, which separates the stratocumulus-topped boundary layer (STBL from the free troposphere (FT. The vertical bounds of the EIL are defined in this work based on considerations of buoyancy and turbulence using thermodynamic and dynamic data. Aerosol number concentrations are examined from three different probes with varying particle diameter (Dp ranges: > 3 nm, > 10 nm, and 0.11–3.4 µm. Relative to the EIL and FT layers, the sub-cloud (SUB layer exhibited lower aerosol number concentrations and higher surface area concentrations. High particle number concentrations between 3 and 10 nm in the EIL are indicative of enhanced nucleation, assisted by high actinic fluxes, cool and moist air, and much lower surface area concentrations than the STBL. Slopes of number concentration versus altitude in the EIL were correlated with the particle number concentration difference between the SUB and lower FT layers. The EIL aerosol size distribution was influenced by varying degrees from STBL aerosol versus subsiding FT aerosol depending on the case examined. These results emphasize the important role of the EIL in influencing nucleation and aerosol–cloud–climate interactions.

  3. Aerosol characteristics in the entrainment interface layer in relation to the marine boundary layer and free troposphere

    Science.gov (United States)

    Dadashazar, Hossein; Braun, Rachel A.; Crosbie, Ewan; Chuang, Patrick Y.; Woods, Roy K.; Jonsson, Haflidi H.; Sorooshian, Armin

    2018-02-01

    This study uses airborne data from two field campaigns off the California coast to characterize aerosol size distribution characteristics in the entrainment interface layer (EIL), a thin and turbulent layer above marine stratocumulus cloud tops, which separates the stratocumulus-topped boundary layer (STBL) from the free troposphere (FT). The vertical bounds of the EIL are defined in this work based on considerations of buoyancy and turbulence using thermodynamic and dynamic data. Aerosol number concentrations are examined from three different probes with varying particle diameter (Dp) ranges: > 3 nm, > 10 nm, and 0.11-3.4 µm. Relative to the EIL and FT layers, the sub-cloud (SUB) layer exhibited lower aerosol number concentrations and higher surface area concentrations. High particle number concentrations between 3 and 10 nm in the EIL are indicative of enhanced nucleation, assisted by high actinic fluxes, cool and moist air, and much lower surface area concentrations than the STBL. Slopes of number concentration versus altitude in the EIL were correlated with the particle number concentration difference between the SUB and lower FT layers. The EIL aerosol size distribution was influenced by varying degrees from STBL aerosol versus subsiding FT aerosol depending on the case examined. These results emphasize the important role of the EIL in influencing nucleation and aerosol-cloud-climate interactions.

  4. Low cloud investigations for project FIRE: Island studies of cloud properties, surface radiation, and boundary layer dynamics. A simulation of the reflectivity over a stratocumulus cloud deck by the Monte Carlo method. M.S. Thesis Final Report

    Science.gov (United States)

    Ackerman, Thomas P.; Lin, Ruei-Fong

    1993-01-01

    The radiation field over a broken stratocumulus cloud deck is simulated by the Monte Carlo method. We conducted four experiments to investigate the main factor for the observed shortwave reflectively over the FIRE flight 2 leg 5, in which reflectivity decreases almost linearly from the cloud center to cloud edge while the cloud top height and the brightness temperature remain almost constant through out the clouds. From our results, the geometry effect, however, did not contribute significantly to what has been observed. We found that the variation of the volume extinction coefficient as a function of its relative position in the cloud affects the reflectivity efficiently. Additional check of the brightness temperature of each experiment also confirms this conclusion. The cloud microphysical data showed some interesting features. We found that the cloud droplet spectrum is nearly log-normal distributed when the clouds were solid. However, whether the shift of cloud droplet spectrum toward the larger end is not certain. The decrease of number density from cloud center to cloud edges seems to have more significant effects on the optical properties.

  5. U.S. Marine Corps Communication-Electronics School Training Process: Discrete-Event Simulation and Lean Options

    National Research Council Canada - National Science Library

    Neu, Charles R; Davenport, Jon; Smith, William R

    2007-01-01

    This paper uses discrete-event simulation modeling, inventory-reduction, and process improvement concepts to identify and analyze possibilities for improving the training continuum at the Marine Corps...

  6. Matlab/Simulink-based simulation for digital-control system of marine three-shaft gas-turbine

    International Nuclear Information System (INIS)

    Yu Youhong; Chen Lingen; Sun Fengrui; Wu Chih

    2005-01-01

    A gas-turbine plant model is required in order to design and develop its control system. In this paper, a simulation model of a marine three-shaft gas-turbine's digital-control system is presented. Acceleration processes are simulated via a Matlab/Simulink program. The effects of some of the main variables on the system's performance are analyzed and the optimum values of parameters obtained. A simulation experiment upon a real gas-turbine plant is performed using the digital-control model. The results show that the simulation model is reliable

  7. Using numerical model simulations to improve the understanding of micro-plastic distribution and pathways in the marine environment

    NARCIS (Netherlands)

    Hardesty, Britta D.; Harari, Joseph; Isobe, Atsuhiko; Lebreton, Laurent; Maximenko, Nikolai; Potemra, Jim; van Sebille, Erik; Vethaak, A.Dick; Wilcox, Chris

    2017-01-01

    Numerical modeling is one of the key tools with which we can gain insight into the distribution of marine litter, especially micro-plastics. Over the past decade, a series of numerical simulations have been constructed that specifically target floating marine litter, based on ocean models of various

  8. Electron beam treatment of simulated marine diesel exhaust gases

    Directory of Open Access Journals (Sweden)

    Licki Janusz

    2015-09-01

    Full Text Available The exhaust gases from marine diesel engines contain high SO2 and NOx concentration. The applicability of the electron beam flue gas treatment technology for purification of marine diesel exhaust gases containing high SO2 and NOx concentration gases was the main goal of this paper. The study was performed in the laboratory plant with NOx concentration up to 1700 ppmv and SO2 concentration up to 1000 ppmv. Such high NOx and SO2 concentrations were observed in the exhaust gases from marine high-power diesel engines fuelled with different heavy fuel oils. In the first part of study the simulated exhaust gases were irradiated by the electron beam from accelerator. The simultaneous removal of SO2 and NOx were obtained and their removal efficiencies strongly depend on irradiation dose and inlet NOx concentration. For NOx concentrations above 800 ppmv low removal efficiencies were obtained even if applied high doses. In the second part of study the irradiated gases were directed to the seawater scrubber for further purification. The scrubbing process enhances removal efficiencies of both pollutants. The SO2 removal efficiencies above 98.5% were obtained with irradiation dose greater than 5.3 kGy. For inlet NOx concentrations of 1700 ppmv the NOx removal efficiency about 51% was obtained with dose greater than 8.8 kGy. Methods for further increase of NOx removal efficiency are presented in the paper.

  9. The highs and lows of cloud radiative feedback: Comparing observational data and CMIP5 models

    Science.gov (United States)

    Jenney, A.; Randall, D. A.

    2014-12-01

    Clouds play a complex role in the climate system, and remain one of the more difficult aspects of the future climate to predict. Over subtropical eastern ocean basins, particularly next to California, Peru, and Southwest Africa, low marine stratocumulus clouds (MSC) help to reduce the amount of solar radiation that reaches the surface by reflecting incident sunlight. The climate feedback associated with these clouds is thought to be positive. This project looks at CMIP5 models and compares them to observational data from CERES and ERA-Interim to try and find observational evidence and model agreement for low, marine stratocumulus cloud feedback. Although current evidence suggests that the low cloud feedback is positive (IPCC, 2014), an analysis of the simulated relationship between July lower tropospheric stability (LTS) and shortwave cloud forcing in MSC regions suggests that this feedback is not due to changes in LTS. IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.

  10. Qualitative and Quantitative Analysis of Congested Marine Traffic Environment – An Application Using Marine Traffic Simulation System

    Directory of Open Access Journals (Sweden)

    Kazuhiko Hasegawa

    2013-06-01

    Full Text Available Difficulty of sailing is quite subjective matter. It depends on various factors. Using Marine Traffic Simulation System (MTSS developed by Osaka University this challenging subject is discussed. In this system realistic traffic flow including collision avoidance manoeuvres can be reproduced in a given area. Simulation is done for southward of Tokyo Bay, Strait of Singapore and off-Shanghai area changing traffic volume from 5 or 50 to 150 or 200% of the present volume. As a result, strong proportional relation between near-miss ratio and traffic density per hour per sailed area is found, independent on traffic volume, area size and configuration. The quantitative evaluation index of the difficulty of sailing, here called risk rate of the area is defined using thus defined traffic density and near-miss ratio.

  11. Atmospheric Corrosion Behavior and Mechanism of a Ni-Advanced Weathering Steel in Simulated Tropical Marine Environment

    Science.gov (United States)

    Wu, Wei; Zeng, Zhongping; Cheng, Xuequn; Li, Xiaogang; Liu, Bo

    2017-12-01

    Corrosion behavior of Ni-advanced weathering steel, as well as carbon steel and conventional weathering steel, in a simulated tropical marine atmosphere was studied by field exposure and indoor simulation tests. Meanwhile, morphology and composition of corrosion products formed on the exposed steels were surveyed through scanning electron microscopy, energy-dispersive x-ray spectroscopy and x-ray diffraction. Results indicated that the additive Ni in weathering steel played an important role during the corrosion process, which took part in the formation of corrosion products, enriched in the inner rust layer and promoted the transformation from loose γ-FeOOH to dense α-FeOOH. As a result, the main aggressive ion, i.e., Cl-, was effectively separated in the outer rust layer which leads to the lowest corrosion rate among these tested steels. Thus, the resistance of Ni-advanced weathering steel to atmospheric corrosion was significantly improved in a simulated tropical marine environment.

  12. Numerical Simulation of Condensation of Sulfuric Acid and Water in a Large Two-stroke Marine Diesel Engine

    DEFF Research Database (Denmark)

    Walther, Jens Honore; Karvounis, Nikolas; Pang, Kar Mun

    2016-01-01

    We present results from computational fluid dynamics simulations of the condensation of sulfuric acid (H2SO4) and water (H2O) in a large two-stroke marine diesel engine. The model uses a reduced n-heptane skeletal chemical mechanism coupled with a sulfur subsetto simulate the combustion process...

  13. Marine ARM GPCI Investigation of Clouds (MAGIC) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Ernie R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-01

    The Marine ARM GPCI Investigation of Clouds (MAGIC) field campaign, which deployed the second ARM Mobile Facility (AMF2) aboard the Horizon Lines cargo container ship Spirit as it ran its regular route between Los Angeles, California and Honolulu, Hawaii, measured properties of clouds and precipitation, aerosols, radiation, and atmospheric, meteorological, and oceanic conditions with the goal of obtaining statistics of these properties to achieve better understanding of the transition between stratocumulus and cumulus cloud regimes that occur in that region. This Sc-Cu transition is poorly represented in models, and a major reason for this is the lack of high-quality and comprehensive data that can be used to constrain, validate, and improve model representation of the transition. MAGIC consisted of 20 round trips between Los Angeles and Honolulu, and thus over three dozen transects through the transition, totaling nearly 200 days at sea between September, 2012 and October, 2013. During this time MAGIC collected a unique and unprecedented data set, including more than 550 successful radiosonde launches. An Intensive Observational Period (IOP) occurred in July, 2013 during which more detailed measurements of the atmospheric structure were made. MAGIC was very successful in its operations and overcame numerous logistical and technological challenges, clearly demonstrating the feasibility of a marine AMF2 deployment and the ability to make accurate measurements of clouds and precipitation, aerosols, and radiation while at sea.

  14. CFD simulations on marine burner flames

    DEFF Research Database (Denmark)

    Cafaggi, Giovanni; Jensen, Peter Arendt; Glarborg, Peter

    The marine industry is changing with new demands concerning high energy efficiency, fuel flexibility and lower emissions of NOX and SOX. A collaboration between the company Alfa Laval and Technical University of Denmark has been established to support the development of the next generation...... of marine burners. The resulting auxiliary boilers shall be compact and able to operate with different fuel types, while reducing NOX emissions. The specific boiler object of this study uses a swirl stabilized liquid fuel burner, with a pressure swirl spill-return atomizer (Fig.1). The combustion chamber...... is enclosed in a water jacket used for water heating and evaporation, and a convective heat exchanger at the furnace outlet super-heats the steam. The purpose of the present study is to gather detailed knowledge about the influence of fuel spray conditions on marine utility boiler flames. The main goal...

  15. On the Nature and Extent of Optically Thin Marine low Clouds

    Science.gov (United States)

    Leahy, L. V.; Wood, R.; Charlson, R. J.; Hostetler, C. A.; Rogers, R. R.; Vaughan, M. A.; Winker, D. M.

    2012-01-01

    Macrophysical properties of optically thin marine low clouds over the nonpolar oceans (60 deg S-60 deg N) are measured using 2 years of full-resolution nighttime data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Optically thin clouds, defined as the subset of marine low clouds that do not fully attenuate the lidar signal, comprise almost half of the low clouds over the marine domain. Regionally, the fraction of low clouds that are optically thin (f(sub thin,cld)) exhibits a strong inverse relationship with the low-cloud cover, with maxima in the tropical trades (f(sub thin,cld) greater than 0.8) and minima in regions of persistent marine stratocumulus and in midlatitudes (f(sub thin,cld) less than 0.3). Domain-wide, a power law fit describes the cloud length distribution, with exponent beta = 2.03 +/- 0.06 (+/-95% confidence interval). On average, the fraction of a cloud that is optically thin decreases from approximately 1 for clouds smaller than 2 km to less than 0.3 for clouds larger than 30 km. This relationship is found to be independent of region, so that geographical variations in the cloud length distribution explain three quarters of the variance in f(sub thin,cld). Comparing collocated trade cumulus observations from CALIOP and the airborne High Spectral Resolution Lidar reveals that clouds with lengths smaller than are resolvable with CALIOP contribute approximately half of the low clouds in the region sampled. A bounded cascade model is constructed to match the observations from the trades. The model shows that the observed optically thin cloud behavior is consistent with a power law scaling of cloud optical depth and suggests that most optically thin clouds only partially fill the CALIOP footprint.

  16. An intercomparison of methods for solving the stochastic collection equation with a focus on cloud radar Doppler spectra in drizzling stratocumulus

    Science.gov (United States)

    Lee, H.; Fridlind, A. M.; Ackerman, A. S.; Kollias, P.

    2017-12-01

    Cloud radar Doppler spectra provide rich information for evaluating the fidelity of particle size distributions from cloud models. The intrinsic simplifications of bulk microphysics schemes generally preclude the generation of plausible Doppler spectra, unlike bin microphysics schemes, which develop particle size distributions more organically at substantial computational expense. However, bin microphysics schemes face the difficulty of numerical diffusion leading to overly rapid large drop formation, particularly while solving the stochastic collection equation (SCE). Because such numerical diffusion can cause an even greater overestimation of radar reflectivity, an accurate method for solving the SCE is essential for bin microphysics schemes to accurately simulate Doppler spectra. While several methods have been proposed to solve the SCE, here we examine those of Berry and Reinhardt (1974, BR74), Jacobson et al. (1994, J94), and Bott (2000, B00). Using a simple box model to simulate drop size distribution evolution during precipitation formation with a realistic kernel, it is shown that each method yields a converged solution as the resolution of the drop size grid increases. However, the BR74 and B00 methods yield nearly identical size distributions in time, whereas the J94 method produces consistently larger drops throughout the simulation. In contrast to an earlier study, the performance of the B00 method is found to be satisfactory; it converges at relatively low resolution and long time steps, and its computational efficiency is the best among the three methods considered here. Finally, a series of idealized stratocumulus large-eddy simulations are performed using the J94 and B00 methods. The reflectivity size distributions and Doppler spectra obtained from the different SCE solution methods are presented and compared with observations.

  17. Modelling and simulation of Holocene marine terrace development in Boso Peninsula, central Japan

    Science.gov (United States)

    Noda, Akemi; Miyauchi, Takahiro; Sato, Toshinori; Matsu'ura, Mitsuhiro

    2018-04-01

    In the southern part of Boso Peninsula, central Japan, we can observe a series of well-developed Holocene marine terraces. We modeled the development of these marine terraces by considering sea-level fluctuation and steady land uplift. The evolution of coastal landform is generally described as follows: altitude change = - erosion + deposition - sea-level rise + land uplift. In this study, the erosion rate is supposed to be proportional to the dissipation rate of wave energy, and the deposition rate of eroded materials to decay exponentially as they are transported seaward. The rate of sea-level rise is given by the time derivative of a sea-level curve obtained from the sediment core records of oxygen isotope ratios. Steady plate subduction generally brings about steady crustal uplift/subsidence independently of earthquake occurrence, and so the land-uplift rate is regarded as time independent on a long-term average. Our simulation results show that a pair of sea cliff and abrasion platform is efficiently formed about a stationary point of the sea-level curve. The Holocene sea-level curve has four peaks and three troughs, and so basically seven terraces are formed one by one during the past 10,000 yr. However, when the land-uplift rate is low, most of the terraces formed at older times sink in the sea. When the land-uplift rate is high, the overlap and/or reverse of older and younger terraces occur frequently, and so the correspondence between the age and present altitude of terraces is not necessarily one-to-one. Taking the land-uplift rate to be 3-4 mm/yr, we can reproduce a series of well-developed Holocene marine terraces in Boso Peninsula independently of coseismic uplifts. From these simulation results, we may conclude that the Holocene marine terraces in Boso Peninsula were developed as a result of the composite process of sea-level fluctuation and steady coastal uplift.

  18. RANS simulation of cavitation and hull pressure fluctuation for marine propeller operating behind-hull condition

    Science.gov (United States)

    Paik, Kwang-Jun; Park, Hyung-Gil; Seo, Jongsoo

    2013-12-01

    Simulations of cavitation flow and hull pressure fluctuation for a marine propeller operating behind a hull using the unsteady Reynolds-Averaged Navier-Stokes equations (RANS) are presented. A full hull body submerged under the free surface is modeled in the computational domain to simulate directly the wake field of the ship at the propeller plane. Simulations are performed in design and ballast draught conditions to study the effect of cavitation number. And two propellers with slightly different geometry are simulated to validate the detectability of the numerical simulation. All simulations are performed using a commercial CFD software FLUENT. Cavitation patterns of the simulations show good agreement with the experimental results carried out in Samsung CAvitation Tunnel (SCAT). The simulation results for the hull pressure fluctuation induced by a propeller are also compared with the experimental results showing good agreement in the tendency and amplitude, especially, for the first blade frequency.

  19. RANS simulation of cavitation and hull pressure fluctuation for marine propeller operating behind-hull condition

    Directory of Open Access Journals (Sweden)

    Kwang-Jun Paik

    2013-12-01

    Full Text Available Simulations of cavitation flow and hull pressure fluctuation for a marine propeller operating behind a hull using the unsteady Reynolds-Averaged Navier-Stokes equations (RANS are presented. A full hull body submerged under the free surface is modeled in the computational domain to simulate directly the wake field of the ship at the propeller plane. Simulations are performed in design and ballast draught conditions to study the effect of cavitation number. And two propellers with slightly different geometry are simulated to validate the detectability of the numerical simulation. All simulations are performed using a commercial CFD software FLUENT. Cavitation patterns of the simulations show good agreement with the experimental results carried out in Samsung CAvitation Tunnel (SCAT. The simulation results for the hull pressure fluctuation induced by a propeller are also compared with the experimental results showing good agreement in the tendency and amplitude, especially, for the first blade frequency.

  20. The "Grey Zone" cold air outbreak global model intercomparison: A cross evaluation using large-eddy simulations

    Science.gov (United States)

    Tomassini, Lorenzo; Field, Paul R.; Honnert, Rachel; Malardel, Sylvie; McTaggart-Cowan, Ron; Saitou, Kei; Noda, Akira T.; Seifert, Axel

    2017-03-01

    A stratocumulus-to-cumulus transition as observed in a cold air outbreak over the North Atlantic Ocean is compared in global climate and numerical weather prediction models and a large-eddy simulation model as part of the Working Group on Numerical Experimentation "Grey Zone" project. The focus of the project is to investigate to what degree current convection and boundary layer parameterizations behave in a scale-adaptive manner in situations where the model resolution approaches the scale of convection. Global model simulations were performed at a wide range of resolutions, with convective parameterizations turned on and off. The models successfully simulate the transition between the observed boundary layer structures, from a well-mixed stratocumulus to a deeper, partly decoupled cumulus boundary layer. There are indications that surface fluxes are generally underestimated. The amount of both cloud liquid water and cloud ice, and likely precipitation, are under-predicted, suggesting deficiencies in the strength of vertical mixing in shear-dominated boundary layers. But also regulation by precipitation and mixed-phase cloud microphysical processes play an important role in the case. With convection parameterizations switched on, the profiles of atmospheric liquid water and cloud ice are essentially resolution-insensitive. This, however, does not imply that convection parameterizations are scale-aware. Even at the highest resolutions considered here, simulations with convective parameterizations do not converge toward the results of convection-off experiments. Convection and boundary layer parameterizations strongly interact, suggesting the need for a unified treatment of convective and turbulent mixing when addressing scale-adaptivity.

  1. [Dynamics of 95Zr in simulated marine water-sediment-organisms system].

    Science.gov (United States)

    Wang, Chunlin; Shi, Jianjun; Sun, Pingyue; Li, Mingyun

    2003-06-01

    To provide scientific evidence to evaluate the behavior of 95Zr in ocean ecosystem, the dynamic model of the transference, accumulation and disappearance of 95Zr among the simulated marine water, sediment and organisms was investigated using Nassarius semiplicatus and Boleophthalums pectinirostris as experimental stuffs. The result showed that 95Zr(Bq.g-1 or Bq.ml-1) in the marine water was decreased more than 90% in the first 4 h, and then descended gradually. 95Zr in sediment was increased in the peak in 48 h and then declined. The radioactivity percent of 95Zr in the shell and muslce of Nassarius semiplicatus was 68.7% and 31.30% respectively, while the radioactivity percent was 22.80%, 12.64%, 34.82%, 10.31%, 4.48%, 11.55% and 3.71%, respectively in the fill, fin, viscera, skull, skin, vertebra and muscle of Boleophthalmus pectinirostris. Nassarius semiplicatus had a greater concentrating capability of 95Zr than Boleophthalmus pectinirostris. The order of the 95Zr concentration was found to be sediment > Nassarius semiplicatus > water > Boleophthalmus pectinirostris. A dynamic model of closed four-compartment was constructed with exponent function.

  2. Assimilation of Ocean-Color Plankton Functional Types to Improve Marine Ecosystem Simulations

    Science.gov (United States)

    Ciavatta, S.; Brewin, R. J. W.; Skákala, J.; Polimene, L.; de Mora, L.; Artioli, Y.; Allen, J. I.

    2018-02-01

    We assimilated phytoplankton functional types (PFTs) derived from ocean color into a marine ecosystem model, to improve the simulation of biogeochemical indicators and emerging properties in a shelf sea. Error-characterized chlorophyll concentrations of four PFTs (diatoms, dinoflagellates, nanoplankton, and picoplankton), as well as total chlorophyll for comparison, were assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The reanalysis simulations spanned the years 1998-2003. The skill of the reference and reanalysis simulations in estimating ocean color and in situ biogeochemical data were compared by using robust statistics. The reanalysis outperformed both the reference and the assimilation of total chlorophyll in estimating the ocean-color PFTs (except nanoplankton), as well as the not-assimilated total chlorophyll, leading the model to simulate better the plankton community structure. Crucially, the reanalysis improved the estimates of not-assimilated in situ data of PFTs, as well as of phosphate and pCO2, impacting the simulation of the air-sea carbon flux. However, the reanalysis increased further the model overestimation of nitrate, in spite of increases in plankton nitrate uptake. The method proposed here is easily adaptable for use with other ecosystem models that simulate PFTs, for, e.g., reanalysis of carbon fluxes in the global ocean and for operational forecasts of biogeochemical indicators in shelf-sea ecosystems.

  3. Using In Situ Observations and Satellite Retrievals to Constrain Large-Eddy Simulations and Single-Column Simulations: Implications for Boundary-Layer Cloud Parameterization in the NASA GISS GCM

    Science.gov (United States)

    Remillard, J.

    2015-12-01

    Two low-cloud periods from the CAP-MBL deployment of the ARM Mobile Facility at the Azores are selected through a cluster analysis of ISCCP cloud property matrices, so as to represent two low-cloud weather states that the GISS GCM severely underpredicts not only in that region but also globally. The two cases represent (1) shallow cumulus clouds occurring in a cold-air outbreak behind a cold front, and (2) stratocumulus clouds occurring when the region was dominated by a high-pressure system. Observations and MERRA reanalysis are used to derive specifications used for large-eddy simulations (LES) and single-column model (SCM) simulations. The LES captures the major differences in horizontal structure between the two low-cloud fields, but there are unconstrained uncertainties in cloud microphysics and challenges in reproducing W-band Doppler radar moments. The SCM run on the vertical grid used for CMIP-5 runs of the GCM does a poor job of representing the shallow cumulus case and is unable to maintain an overcast deck in the stratocumulus case, providing some clues regarding problems with low-cloud representation in the GCM. SCM sensitivity tests with a finer vertical grid in the boundary layer show substantial improvement in the representation of cloud amount for both cases. GCM simulations with CMIP-5 versus finer vertical gridding in the boundary layer are compared with observations. The adoption of a two-moment cloud microphysics scheme in the GCM is also tested in this framework. The methodology followed in this study, with the process-based examination of different time and space scales in both models and observations, represents a prototype for GCM cloud parameterization improvements.

  4. Drivers of Seasonal Variability in Marine Boundary Layer Aerosol Number Concentration Investigated Using a Steady State Approach

    Science.gov (United States)

    Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy; Eastman, Ryan; Luke, Edward

    2018-01-01

    Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (Na). These terms are then parameterized, and by assuming that on seasonal time scales Na is in steady state, the budget equation is rearranged to form a diagnostic equation for Na based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-Section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter Na concentrations are made using the simplified steady state model and seasonal mean observed variables. These are found to match well with the observed Na. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g., precipitation rate and free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in Na, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.

  5. Observations of the boundary layer, cloud, and aerosol variability in the southeast Pacific coastal marine stratocumulus during VOCALS-REx

    Science.gov (United States)

    Zheng, X.; Albrecht, B.; Jonsson, H. H.; Khelif, D.; Feingold, G.; Minnis, P.; Ayers, K.; Chuang, P.; Donaher, S.; Rossiter, D.; Ghate, V.; Ruiz-Plancarte, J.; Sun-Mack, S.

    2011-05-01

    Aircraft observations made off the coast of northern Chile in the Southeastern Pacific (20° S, 72° W; named Point Alpha) from 16 October to 13 November 2008 during the VAMOS Ocean-Cloud-Atmosphere-Land Study-Regional Experiment (VOCALS-REx), combined with meteorological reanalysis, satellite measurements, and radiosonde data, are used to investigate the boundary layer (BL) and aerosol-cloud-drizzle variations in this region. The BL at Point Alpha was typical of a non-drizzling stratocumulus-topped BL on days without predominately synoptic and meso-scale influences. The BL had a depth of 1140 ± 120 m, was well-mixed and capped by a sharp inversion. The wind direction generally switched from southerly within the BL to northerly above the inversion. The cloud liquid water path (LWP) varied between 15 g m-2 and 160 g m-2. From 29 October to 4 November, when a synoptic system affected conditions at Point Alpha, the cloud LWP was higher than on the other days by around 40 g m-2. On 1 and 2 November, a moist layer above the inversion moved over Point Alpha. The total-water specific humidity above the inversion was larger than that within the BL during these days. Entrainment rates (average of 1.5 ± 0.6 mm s-1) calculated from the near cloud-top fluxes and turbulence (vertical velocity variance) in the BL at Point Alpha appeared to be weaker than those in the BL over the open ocean west of Point Alpha and the BL near the coast of the northeast Pacific. The accumulation mode aerosol varied from 250 to 700 cm-3 within the BL, and CCN at 0.2 % supersaturation within the BL ranged between 150 and 550 cm-3. The main aerosol source at Point Alpha was horizontal advection within the BL from south. The average cloud droplet number concentration ranged between 80 and 400 cm-3, which was consistent with the satellite-derived values. The relationship of cloud droplet number concentration and CCN at 0.2 % supersaturation from 18 flights is Nd =4.6 × CCN0.71. While the mean LWP

  6. Observations of the boundary layer, cloud, and aerosol variability in the southeast Pacific near-coastal marine stratocumulus during VOCALS-REx

    Science.gov (United States)

    Zheng, X.; Albrecht, B.; Jonsson, H. H.; Khelif, D.; Feingold, G.; Minnis, P.; Ayers, K.; Chuang, P.; Donaher, S.; Rossiter, D.; Ghate, V.; Ruiz-Plancarte, J.; Sun-Mack, S.

    2011-09-01

    Aircraft observations made off the coast of northern Chile in the Southeastern Pacific (20° S, 72° W; named Point Alpha) from 16 October to 13 November 2008 during the VAMOS Ocean-Cloud- Atmosphere-Land Study-Regional Experiment (VOCALS-REx), combined with meteorological reanalysis, satellite measurements, and radiosonde data, are used to investigate the boundary layer (BL) and aerosol-cloud-drizzle variations in this region. On days without predominately synoptic and meso-scale influences, the BL at Point Alpha was typical of a non-drizzling stratocumulus-topped BL. Entrainment rates calculated from the near cloud-top fluxes and turbulence in the BL at Point Alpha appeared to be weaker than those in the BL over the open ocean west of Point Alpha and the BL near the coast of the northeast Pacific. The cloud liquid water path (LWP) varied between 15 g m-2 and 160 g m-2. The BL had a depth of 1140 ± 120 m, was generally well-mixed and capped by a sharp inversion without predominately synoptic and meso-scale influences. The wind direction generally switched from southerly within the BL to northerly above the inversion. On days when a synoptic system and related mesoscale costal circulations affected conditions at Point Alpha (29 October-4 November), a moist layer above the inversion moved over Point Alpha, and the total-water mixing ratio above the inversion was larger than that within the BL. The accumulation mode aerosol varied from 250 to 700 cm-3 within the BL, and CCN at 0.2 % supersaturation within the BL ranged between 150 and 550 cm-3. The main aerosol source at Point Alpha was horizontal advection within the BL from south. The average cloud droplet number concentration ranged between 80 and 400 cm-3. While the mean LWP retrieved from GOES was in good agreement with the in situ measurements, the GOES-derived cloud droplet effective radius tended to be larger than that from the aircraft in situ observations near cloud top. The aerosol and cloud LWP

  7. Observations of the boundary layer, cloud, and aerosol variability in the southeast Pacific near-coastal marine stratocumulus during VOCALS-REx

    Directory of Open Access Journals (Sweden)

    X. Zheng

    2011-09-01

    Full Text Available Aircraft observations made off the coast of northern Chile in the Southeastern Pacific (20° S, 72° W; named Point Alpha from 16 October to 13 November 2008 during the VAMOS Ocean-Cloud- Atmosphere-Land Study-Regional Experiment (VOCALS-REx, combined with meteorological reanalysis, satellite measurements, and radiosonde data, are used to investigate the boundary layer (BL and aerosol-cloud-drizzle variations in this region. On days without predominately synoptic and meso-scale influences, the BL at Point Alpha was typical of a non-drizzling stratocumulus-topped BL. Entrainment rates calculated from the near cloud-top fluxes and turbulence in the BL at Point Alpha appeared to be weaker than those in the BL over the open ocean west of Point Alpha and the BL near the coast of the northeast Pacific. The cloud liquid water path (LWP varied between 15 g m−2 and 160 g m−2. The BL had a depth of 1140 ± 120 m, was generally well-mixed and capped by a sharp inversion without predominately synoptic and meso-scale influences. The wind direction generally switched from southerly within the BL to northerly above the inversion. On days when a synoptic system and related mesoscale costal circulations affected conditions at Point Alpha (29 October–4 November, a moist layer above the inversion moved over Point Alpha, and the total-water mixing ratio above the inversion was larger than that within the BL. The accumulation mode aerosol varied from 250 to 700 cm−3 within the BL, and CCN at 0.2 % supersaturation within the BL ranged between 150 and 550 cm−3. The main aerosol source at Point Alpha was horizontal advection within the BL from south. The average cloud droplet number concentration ranged between 80 and 400 cm−3. While the mean LWP retrieved from GOES was in good agreement with the in situ measurements, the GOES-derived cloud droplet effective radius tended to be larger than that from the

  8. Mathematical model of small water-plane area twin-hull and application in marine simulator

    Science.gov (United States)

    Zhang, Xiufeng; Lyu, Zhenwang; Yin, Yong; Jin, Yicheng

    2013-09-01

    Small water-plane area twin-hull (SWATH) has drawn the attention of many researchers due to its good sea-keeping ability. In this paper, MMG's idea of separation was used to perform SWATH movement modeling and simulation; respectively the forces and moment of SWATH were divided into bare hull, propeller, rudder at the fluid hydrodynamics, etc. Wake coefficient at the propellers which reduces thrust coefficient, and rudder mutual interference forces among the hull and propeller, for the calculation of SWATH, were all considered. The fourth-order Runge-Kutta method of integration was used by solving differential equations, in order to get SWATH's movement states. As an example, a turning test at full speed and full starboard rudder of `Seagull' craft is shown. The simulation results show the SWATH's regular pattern and trend of motion. It verifies the correctness of the mathematical model of the turning movement. The SWATH's mathematical model is applied to marine simulator in order to train the pilots or seamen, or safety assessment for ocean engineering project. Lastly, the full mission navigation simulating system (FMNSS) was determined to be a successful virtual reality technology application sample in the field of navigation simulation.

  9. Island based radar and microwave radiometer measurements of stratus cloud parameters during the Atlantic Stratocumulus Transition Experiment (ASTEX)

    Energy Technology Data Exchange (ETDEWEB)

    Frisch, A.S. [Colorado State Univ., Fort Collins, CO (United States); Fairall, C.W.; Snider, J.B. [NOAA Environmental Technology Lab., Boulder, CO (United States); Lenshow, D.H.; Mayer, S.D. [National Center for Atmospheric Research, Boulder, CO (United States)

    1996-04-01

    During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, simultaneous measurements were made with a vertically pointing cloud sensing radar and a microwave radiometer. The radar measurements are used to estimate stratus cloud drizzle and turbulence parameters. In addition, with the microwave radiometer measurements of reflectivity, we estimated the profiles of cloud liquid water and effective radius. We used radar data for computation of vertical profiles of various drizzle parameters such as droplet concentration, modal radius, and spread. A sample of these results is shown in Figure 1. In addition, in non-drizzle clouds, with the radar and radiometer we can estimate the verticle profiles of stratus cloud parameters such as liquid water concentration and effective radius. This is accomplished by assuming a droplet distribution with droplet number concentration and width constant with height.

  10. CGILS: Results from the First Phase of an International Project to Understand the Physical Mechanisms of Low Cloud Feedbacks in Single Column Models

    Science.gov (United States)

    Zhang, Minghua; Bretherton, Christopher S.; Blossey, Peter N.; Austin, Phillip H.; Bacmeister, Julio T.; Bony, Sandrine; Brient, Florent; Cheedela, Suvarchal K.; Cheng, Anning; DelGenio, Anthony; hide

    2013-01-01

    1] CGILS-the CFMIP-GASS Intercomparison of Large Eddy Models (LESs) and single column models (SCMs)-investigates the mechanisms of cloud feedback in SCMs and LESs under idealized climate change perturbation. This paper describes the CGILS results from 15 SCMs and 8 LES models. Three cloud regimes over the subtropical oceans are studied: shallow cumulus, cumulus under stratocumulus, and well-mixed coastal stratus/stratocumulus. In the stratocumulus and coastal stratus regimes, SCMs without activated shallow convection generally simulated negative cloud feedbacks, while models with active shallow convection generally simulated positive cloud feedbacks. In the shallow cumulus alone regime, this relationship is less clear, likely due to the changes in cloud depth, lateral mixing, and precipitation or a combination of them. The majority of LES models simulated negative cloud feedback in the well-mixed coastal stratus/stratocumulus regime, and positive feedback in the shallow cumulus and stratocumulus regime. A general framework is provided to interpret SCM results: in a warmer climate, the moistening rate of the cloudy layer associated with the surface-based turbulence parameterization is enhanced; together with weaker large-scale subsidence, it causes negative cloud feedback. In contrast, in the warmer climate, the drying rate associated with the shallow convection scheme is enhanced. This causes positive cloud feedback. These mechanisms are summarized as the "NESTS" negative cloud feedback and the "SCOPE" positive cloud feedback (Negative feedback from Surface Turbulence under weaker Subsidence-Shallow Convection PositivE feedback) with the net cloud feedback depending on how the two opposing effects counteract each other. The LES results are consistent with these interpretations

  11. UCLALES-SALSA v1.0: a large-eddy model with interactive sectional microphysics for aerosol, clouds and precipitation

    Science.gov (United States)

    Tonttila, Juha; Maalick, Zubair; Raatikainen, Tomi; Kokkola, Harri; Kühn, Thomas; Romakkaniemi, Sami

    2017-01-01

    Challenges in understanding the aerosol-cloud interactions and their impacts on global climate highlight the need for improved knowledge of the underlying physical processes and feedbacks as well as their interactions with cloud and boundary layer dynamics. To pursue this goal, increasingly sophisticated cloud-scale models are needed to complement the limited supply of observations of the interactions between aerosols and clouds. For this purpose, a new large-eddy simulation (LES) model, coupled with an interactive sectional description for aerosols and clouds, is introduced. The new model builds and extends upon the well-characterized UCLA Large-Eddy Simulation Code (UCLALES) and the Sectional Aerosol module for Large-Scale Applications (SALSA), hereafter denoted as UCLALES-SALSA. Novel strategies for the aerosol, cloud and precipitation bin discretisation are presented. These enable tracking the effects of cloud processing and wet scavenging on the aerosol size distribution as accurately as possible, while keeping the computational cost of the model as low as possible. The model is tested with two different simulation set-ups: a marine stratocumulus case in the DYCOMS-II campaign and another case focusing on the formation and evolution of a nocturnal radiation fog. It is shown that, in both cases, the size-resolved interactions between aerosols and clouds have a critical influence on the dynamics of the boundary layer. The results demonstrate the importance of accurately representing the wet scavenging of aerosol in the model. Specifically, in a case with marine stratocumulus, precipitation and the subsequent removal of cloud activating particles lead to thinning of the cloud deck and the formation of a decoupled boundary layer structure. In radiation fog, the growth and sedimentation of droplets strongly affect their radiative properties, which in turn drive new droplet formation. The size-resolved diagnostics provided by the model enable investigations of these

  12. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer: An ARM Mobile Facility Deployment

    Science.gov (United States)

    Wood, Robert; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; de Szoeke, Simone; Yuter, Sandra; Miller, Matthew; hide

    2015-01-01

    Capsule: A 21-month deployment to Graciosa Island in the northeastern Atlantic Ocean is providing an unprecedented record of the clouds, aerosols and meteorology in a poorly-sampled remote marine environment The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21 month (April 2009- December 2010) comprehensive dataset documenting clouds, aerosols and precipitation using the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean, and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1- 11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging. The data from at Graciosa are being compared with short-range forecasts made a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well, but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a

  13. Plastic forming simulation analysis of marine engine crankshaft single-throw

    Directory of Open Access Journals (Sweden)

    LIU Peipei

    2016-08-01

    Full Text Available The research object is for marine engine crankshaft single-throw.A 3D model of the crankshaft single-throw blank and die in forging process is established by SolidWorks software,then the 3D model is imported into metal plastic forming CAE software DEFROM-3D to carry on the plastic forming simulation,to verify the relationship between the internal flow stress and the external deformation conditions in the process of metal plastic deformation under different strain rate and temperature,and to carry on the scientific analysis based on the obtained data.The result shows that the preset temperature is higher,the stress-strain curve is relatively lower when the strain rate is constant.Sample internal flow stress will be greater and the resistance to fatigue strength will be poorer at a higher strain rate when the temperature of the blank is constant.The result also provides a theoretical basis for further optimization design.

  14. Understanding the drivers of marine liquid-water cloud occurrence and properties with global observations using neural networks

    Directory of Open Access Journals (Sweden)

    H. Andersen

    2017-08-01

    Full Text Available The role of aerosols, clouds and their interactions with radiation remain among the largest unknowns in the climate system. Even though the processes involved are complex, aerosol–cloud interactions are often analyzed by means of bivariate relationships. In this study, 15 years (2001–2015 of monthly satellite-retrieved near-global aerosol products are combined with reanalysis data of various meteorological parameters to predict satellite-derived marine liquid-water cloud occurrence and properties by means of region-specific artificial neural networks. The statistical models used are shown to be capable of predicting clouds, especially in regions of high cloud variability. On this monthly scale, lower-tropospheric stability is shown to be the main determinant of cloud fraction and droplet size, especially in stratocumulus regions, while boundary layer height controls the liquid-water amount and thus the optical thickness of clouds. While aerosols show the expected impact on clouds, at this scale they are less relevant than some meteorological factors. Global patterns of the derived sensitivities point to regional characteristics of aerosol and cloud processes.

  15. Numerical investigation of the flow in axial water turbines and marine propellers with scale-resolving simulations

    Science.gov (United States)

    Morgut, Mitja; Jošt, Dragica; Nobile, Enrico; Škerlavaj, Aljaž

    2015-11-01

    The accurate prediction of the performances of axial water turbines and naval propellers is a challenging task, of great practical relevance. In this paper a numerical prediction strategy, based on the combination of a trusted CFD solver and a calibrated mass transfer model, is applied to the turbulent flow in axial turbines and around a model scale naval propeller, under non-cavitating and cavitating conditions. Some selected results for axial water turbines and a marine propeller, and in particular the advantages, in terms of accuracy and fidelity, of ScaleResolving Simulations (SRS), like SAS (Scale Adaptive Simulation) and Zonal-LES (ZLES) compared to standard RANS approaches, are presented. Efficiency prediction for a Kaplan and a bulb turbine was significantly improved by use of the SAS SST model in combination with the ZLES in the draft tube. Size of cavitation cavity and sigma break curve for Kaplan turbine were successfully predicted with SAS model in combination with robust high resolution scheme, while for mass transfer the Zwart model with calibrated constants were used. The results obtained for a marine propeller in non-uniform inflow, under cavitating conditions, compare well with available experimental measurements, and proved that a mass transfer model, previously calibrated for RANS (Reynolds Averaged Navier Stokes), can be successfully applied also within the SRS approaches.

  16. Numerical Simulations of Marine Hydrokinetic (MHK) Turbines Using the Blade Element Momentum Theory

    Science.gov (United States)

    Javaherchi, Teymour; Thulin, Oskar; Aliseda, Alberto

    2011-11-01

    Energy extraction from the available kinetic energy in tidal currents via Marine Hydrokinetic (MHK) turbines has recently attracted scientists' attention as a highly predictable source of renewable energy. The strongest tidal resources have a concentrated nature that require close turbine spacing in a farm of MHK turbines. This tight spacing, however, will lead to interaction of the downstream turbines with the turbulent wake generated by upstream turbines. This interaction can significantly reduce the power generated and possibly result in structural failure before the expected service life is completed. Development of a numerical methodology to study the turbine-wake interaction can provide a tool for optimization of turbine spacing to maximize the power generated in turbine arrays. In this work, we will present numerical simulations of the flow field in a farm of horizontal axis MHK turbines using the Blade Element Momentum Theory (BEMT). We compare the value of integral variables (i.e. efficiency, power, torque and etc.) calculated for each turbine in the farm for different arrangements with varying streamwise and lateral offsets between turbines. We find that BEMT provides accurate estimates of turbine efficiency under uniform flow conditions, but overpredicts the efficiency of downstream turbines when they are strongly affected by the wakes. Supported by DOE through the National Northwest Marine Renewable Energy Center.

  17. Identifying oil/marine snow associations in mesocosm simulations of the Deepwater Horizon oil spill event using solid-state 13C NMR spectroscopy.

    Science.gov (United States)

    Hatcher, Patrick G; Obeid, Wassim; Wozniak, Andrew S; Xu, Chen; Zhang, Saijin; Santschi, Peter H; Quigg, Antonietta

    2018-01-01

    The Deepwater Horizon oil spill stimulated the release of marine snow made up of dead/living plankton/bacteria and their exopolymeric polysaccharide substances (EPS), termed marine oil snow (MOS), promoting rapid removal of oil from the water column into sediments near the well site. Mesocosm simulations showed that Macondo surrogate oil readily associates with the marine snow. Quantitative solid-state 13 C NMR readily distinguishes this oil from naturally formed marine snow and reveals that adding the dispersant Corexit enhances the amount of oil associated with the MOS, thus contributing to rapid removal from the water column. Solvent extraction of MOS removes the oil-derived compounds for analysis by one and two-dimensional GC/MS and evaluation of potential transformations they undergo when associated with the EPS. The results reveal that the oil associated with EPS is subjected to rapid transformation, in a matter of days, presumably by bacteria and fungi associated with EPS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Indian deep-sea environment experiment (INDEX): Monitoring the restoration of marine enviroment after artificial disturbance to simulate deep-sea mining in central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.

    the restoration of marine environment after artificial disturbance to simulate deep-sea mining in Central Indian Basin Guest Editor Rahul Sharma Note from guest editor A special issue on Indian Deep-sea Environment Experiment (INDEX) conducted by the scientists... in Geochemical Associations in Artificially Disturbed Deep-Sea Sediments B. Nagender Nath, G. Parthiban, S. Banaulikar, and Subhadeep Sarkar Marine Georesources and Geotechnology, 24:61–62, 2006 Copyright # Taylor & Francis Group, LLC ISSN: 1064-119X print/1521...

  19. Simulating ecological changes caused by marine energy devices

    Science.gov (United States)

    Schuchert, Pia; Elsaesser, Bjoern; Pritchard, Daniel; Kregting, Louise

    2015-04-01

    Marine renewable energy from wave and tidal technology has the potential to contribute significantly globally to energy security for future generations. However common to both tidal and wave energy extraction systems is concern regarding the potential environmental consequences of the deployment of the technology as environmental and ecological effects are so far poorly understood. Ecological surveys and studies to investigate the environmental impacts are time consuming and costly and are generally reactive; a more efficient approach is to develop 2 and 3D linked hydrodynamic-ecological modelling which has the potential to be proactive and to allow forecasting of the effects of array installation. The objective of the study was to explore tools which can help model and evaluate possible far- and near field changes in the environment and ecosystem caused by the introduction of arrays of marine energy devices. Using the commercial software, MIKE by DHI, we can predict and model possible changes in the ecosystem. MIKE21 and ECOLab modelling software provide the opportunity to couple high level hydrodynamic models with process based ecological models and/or agent based models (ABM). The flow solutions of the model were determined in an idealised tidal basin with the dimensions similar to that of Strangford Lough, Northern Ireland, a body of water renowned for the location of the first grid-connected tidal turbine, SeaGen. In the first instance a simple process oriented ecological NPZD model was developed which are used to model marine and freshwater systems describing four state variables, Nutrient, Phytoplankton, Zooplankton and Detritus. The ecological model was run and evaluated under two hydrodynamic scenarios of the idealised basin. This included no tidal turbines (control) and an array of 55 turbines, an extreme scenario. Whilst an array of turbines has an effect on the hydrodynamics of the Lough, it is unlikely to see an extreme effect on the NPZD model

  20. Cloud and Radiation Studies during SAFARI 2000

    Science.gov (United States)

    Platnick, Steven; King, M. D.; Hobbs, P. V.; Osborne, S.; Piketh, S.; Bruintjes, R.; Lau, William K. M. (Technical Monitor)

    2001-01-01

    Though the emphasis of the Southern Africa Regional Science Initiative 2000 (SAFARI-2000) dry season campaign was largely on emission sources and transport, the assemblage of aircraft (including the high altitude NASA ER-2 remote sensing platform and the University of Washington CV-580, UK MRF C130, and South African Weather Bureau JRA in situ aircrafts) provided a unique opportunity for cloud studies. Therefore, as part of the SAFARI initiative, investigations were undertaken to assess regional aerosol-cloud interactions and cloud remote sensing algorithms. In particular, the latter part of the experiment concentrated on marine boundary layer stratocumulus clouds off the southwest coast of Africa. Associated with cold water upwelling along the Benguela current, the Namibian stratocumulus regime has received limited attention but appears to be unique for several reasons. During the dry season, outflow of continental fires and industrial pollution over this area can be extreme. From below, upwelling provides a rich nutrient source for phytoplankton (a source of atmospheric sulphur through DMS production as well as from decay processes). The impact of these natural and anthropogenic sources on the microphysical and optical properties of the stratocumulus is unknown. Continental and Indian Ocean cloud systems of opportunity were also studied during the campaign. Aircraft flights were coordinated with NASA Terra Satellite overpasses for synergy with the Moderate Resolution Imaging Spectroradiometer (MODIS) and other Terra instruments. An operational MODIS algorithm for the retrieval of cloud optical and physical properties (including optical thickness, effective particle radius, and water path) has been developed. Pixel-level MODIS retrievals (11 km spatial resolution at nadir) and gridded statistics of clouds in th SAFARI region will be presented. In addition, the MODIS Airborne Simulator flown on the ER-2 provided high spatial resolution retrievals (50 m at nadir

  1. The use of mesocosms in marine oil spill - ecological research and development

    International Nuclear Information System (INIS)

    Reilly, T.J.

    1999-01-01

    This paper focuses on the design of mesocosms which are partly enclosed, bounded, outdoor experimental systems for simulating marine oil spill environments for use in examining the ecological impact of the spill response. System requirements for mesocosms in marine oil spill ecological research and development are discussed, and the question of scaling, and mesocosm tank features useful in coastal/nearshore ecological marine oil spill research are considered. Details are given of the MERL mesocosm facility at the University of Rhode Island, and the Coastal Oil-Spill Simulation System (COSS) multiple tank mesocosm facility in Texas, and recommendations for the design and use of marine mesocosms in oil spill ecological impact studies are presented. (UK)

  2. Numerical simulation of a cross flow Marine Hydrokinetic turbine.

    Science.gov (United States)

    Hall, Taylor; Aliseda, Alberto

    2011-11-01

    In the search for alternative sources of energy, the kinetic energy of water currents in oceans, rivers and estuaries is being explored as predictable and environmentally benign. We are investigating the flow past a cross flow turbine in which a helical blade under hydrodynamic forces turns around a shaft perpendicular to the free stream. This type of turbine, while very different from the classical horizontal axis turbine commonly used in the wind energy field, presents advantages for stacking in very narrow constricted channels where the water currents are consistently high and therefore turbine installation may be economically feasible. We use a model of a helical four-bladed turbine in cross flow to investigate the efficiency of the energy capture and the dynamics of the turbulent wake. Scale model experiments in a flume are used to validate the numerical results on a stationary configuration as an initial step towards creating an accurate numerical model of the turbine. The simulation of the rotating turbine provides a full perspective on the effect of angular position on flow detachment and vortex shedding from the blade, as well as on the fluctuations of the shaft torque produced (a problematic feature of this type of turbine). The results are analyzed in terms of hydrodynamic optimization of the blade and its structural loading. Supported by DOE through the Northwest National Marine Renewable Energy Center.

  3. Simulating wind and marine hydrokinetic turbines with actuator lines in RANS and LES

    Science.gov (United States)

    Bachant, Peter; Wosnik, Martin

    2015-11-01

    As wind and marine hydrokinetic (MHK) turbine designs mature, focus is shifting towards improving turbine array layouts for maximizing overall power output, i.e., minimizing wake interference for axial-flow or horizontal-axis turbines, or taking advantage of constructive wake interaction for cross-flow or vertical-axis turbines. Towards this goal, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier-Stokes models. The ALM predicts turbine loading with the blade element method combined with sub-models for dynamic stall and flow curvature. The open-source software is written as an extension library for the OpenFOAM CFD package, which allows the ALM body force to be applied to their standard RANS and LES solvers. Turbine forcing is also applied to volume of fluid (VOF) models, e.g., for predicting free surface effects on submerged MHK devices. An additional sub-model is considered for injecting turbulence model scalar quantities based on actuator line element loading. Results are presented for the simulation of performance and wake dynamics of axial- and cross-flow turbines and compared with moderate Reynolds number experiments and body-fitted mesh, blade-resolving CFD. Work supported by NSF-CBET grant 1150797.

  4. Evaluation of Forecasted Southeast Pacific Stratocumulus in the NCAR, GFDL and ECMWF Models

    Energy Technology Data Exchange (ETDEWEB)

    Hannay, C; Williamson, D L; Hack, J J; Kiehl, J T; Olson, J G; Klein, S A; Bretherton, C S; K?hler, M

    2008-01-24

    We examine forecasts of Southeast Pacific stratocumulus at 20S and 85W during the East Pacific Investigation of Climate (EPIC) cruise of October 2001 with the ECMWF model, the Atmospheric Model (AM) from GFDL, the Community Atmosphere Model (CAM) from NCAR, and the CAM with a revised atmospheric boundary layer formulation from the University of Washington (CAM-UW). The forecasts are initialized from ECMWF analyses and each model is run for 3 days to determine the differences with the EPIC field data. Observations during the EPIC cruise show a stable and well-mixed boundary layer under a sharp inversion. The inversion height and the cloud layer have a strong and regular diurnal cycle. A key problem common to the four models is that the forecasted planetary boundary layer (PBL) height is too low when compared to EPIC observations. All the models produce a strong diurnal cycle in the Liquid Water Path (LWP) but there are large differences in the amplitude and the phase compared to the EPIC observations. This, in turn, affects the radiative fluxes at the surface. There is a large spread in the surface energy budget terms amongst the models and large discrepancies with observational estimates. Single Column Model (SCM) experiments with the CAM show that the vertical pressure velocity has a large impact on the PBL height and LWP. Both the amplitude of the vertical pressure velocity field and its vertical structure play a significant role in the collapse or the maintenance of the PBL.

  5. Corrosion products of reinforcement in concrete in marine and industrial environments

    International Nuclear Information System (INIS)

    Vera, R.; Villarroel, M.; Carvajal, A.M.; Vera, E.; Ortiz, C.

    2009-01-01

    The corrosion products formed on embedded steel in concrete under simulated marine and industrial conditions and natural marine environment were studied. A 0.50 water/cement ratio concrete was used and 3.5% NaCl and 180 g L -1 of H 2 SO 4 with 70 ppm of chloride ions solutions were used to simulate the synthetic medium. The initial electrochemical variables of the steel and pH, chlorides and sulfates profiles were measured according to the concrete depth. The morphology of the corrosive attack was determined via scanning electron microscopy (SEM), and the composition of the corrosion products was determined using an X-ray analyzer and an X-ray diffractometer (XRD). The protective power of the corrosion products was evaluated through anodic polarization curves in a saturated Ca(OH) 2 solution. The results from XRD and SEM show that all the resulting corrosion products correspond to lepidocrocite, goethite and magnetite mixtures; moreover, akaganeite was also identified under natural and simulated marine environments. Siderite was only detected in samples exposed to a natural marine environment. Concerning the protective nature of the corrosion products, these show lower performance in a simulated industrial environment, where the corrosion rate of the steel is up to 1.48 μm year -1

  6. Corrosion products of reinforcement in concrete in marine and industrial environments

    Energy Technology Data Exchange (ETDEWEB)

    Vera, R. [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Avenida Brasil 2950, Casilla 4059, Valparaiso (Chile)], E-mail: rvera@ucv.cl; Villarroel, M. [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Avenida Brasil 2950, Casilla 4059, Valparaiso (Chile); Carvajal, A.M. [Facultad de Ingenieria, Escuela de Construccion Civil, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, Macul, Santiago (Chile); Vera, E.; Ortiz, C. [Universidad Pedagogica y Tecnologica de Colombia, Avenida Central Norte, Km 2, Tunja (Colombia)

    2009-03-15

    The corrosion products formed on embedded steel in concrete under simulated marine and industrial conditions and natural marine environment were studied. A 0.50 water/cement ratio concrete was used and 3.5% NaCl and 180 g L{sup -1} of H{sub 2}SO{sub 4} with 70 ppm of chloride ions solutions were used to simulate the synthetic medium. The initial electrochemical variables of the steel and pH, chlorides and sulfates profiles were measured according to the concrete depth. The morphology of the corrosive attack was determined via scanning electron microscopy (SEM), and the composition of the corrosion products was determined using an X-ray analyzer and an X-ray diffractometer (XRD). The protective power of the corrosion products was evaluated through anodic polarization curves in a saturated Ca(OH){sub 2} solution. The results from XRD and SEM show that all the resulting corrosion products correspond to lepidocrocite, goethite and magnetite mixtures; moreover, akaganeite was also identified under natural and simulated marine environments. Siderite was only detected in samples exposed to a natural marine environment. Concerning the protective nature of the corrosion products, these show lower performance in a simulated industrial environment, where the corrosion rate of the steel is up to 1.48 {mu}m year{sup -1}.

  7. The Impact of High-Resolution Sea Surface Temperatures on the Simulated Nocturnal Florida Marine Boundary Layer

    Science.gov (United States)

    LaCasse, Katherine M.; Splitt, Michael E.; Lazarus, Steven M.; Lapenta, William M.

    2008-01-01

    High- and low-resolution sea surface temperature (SST) analysis products are used to initialize the Weather Research and Forecasting (WRF) Model for May 2004 for short-term forecasts over Florida and surrounding waters. Initial and boundary conditions for the simulations were provided by a combination of observations, large-scale model output, and analysis products. The impact of using a 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) SST composite on subsequent evolution of the marine atmospheric boundary layer (MABL) is assessed through simulation comparisons and limited validation. Model results are presented for individual simulations, as well as for aggregates of easterly- and westerly-dominated low-level flows. The simulation comparisons show that the use of MODIS SST composites results in enhanced convergence zones. earlier and more intense horizontal convective rolls. and an increase in precipitation as well as a change in precipitation location. Validation of 10-m winds with buoys shows a slight improvement in wind speed. The most significant results of this study are that 1) vertical wind stress divergence and pressure gradient accelerations across the Florida Current region vary in importance as a function of flow direction and stability and 2) the warmer Florida Current in the MODIS product transports heat vertically and downwind of this heat source, modifying the thermal structure and the MABL wind field primarily through pressure gradient adjustments.

  8. Clouds, Aerosols, and Precipitation in the Marine Boundary Layer: An Arm Mobile Facility Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Robert; Wyant, Matthew; Bretherton, Christopher S.; Rémillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; de Szoeke, Simone; Yuter, Sandra; Miller, Matthew; Mechem, David; Tselioudis, George; Chiu, J. Christine; Mann, Julian A. L.; O’Connor, Ewan J.; Hogan, Robin J.; Dong, Xiquan; Miller, Mark; Ghate, Virendra; Jefferson, Anne; Min, Qilong; Minnis, Patrick; Palikonda, Rabindra; Albrecht, Bruce; Luke, Ed; Hannay, Cecile; Lin, Yanluan

    2015-03-01

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) 38 deployment at Graciosa Island in the Azores generated a 21 month (April 2009-December 2010) 39 comprehensive dataset documenting clouds, aerosols and precipitation using the Atmospheric 40 Radiation Measurement (ARM) Mobile Facility (AMF). The scientific aim of the deployment is 41 to gain improved understanding of the interactions of clouds, aerosols and precipitation in the 42 marine boundary layer. 43 Graciosa Island straddles the boundary between the subtropics and midlatitudes in the 44 Northeast Atlantic Ocean, and consequently experiences a great diversity of meteorological and 45 cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus 46 occurring regularly. Approximately half of all clouds contained precipitation detectable as radar 47 echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-48 11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide 49 range of aerosol conditions was sampled during the deployment consistent with the diversity of 50 sources as indicated by back trajectory analysis. Preliminary findings suggest important two-way 51 interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation 52 and cloud radiative properties while being controlled in part by precipitation scavenging. 53 The data from at Graciosa are being compared with short-range forecasts made a variety 54 of models. A pilot analysis with two climate and two weather forecast models shows that they 55 reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well, 56 but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to 57 be a long-term ARM site that became operational in October 2013.

  9. Influence of physical and chemical dispersion on the biodegradation of oil under simulated marine conditions

    International Nuclear Information System (INIS)

    Swannell, R. P. J.; Daniel, F.; Croft, B. C.; Engelhardt, M. A.; Wilson, S.; Mitchell, D. J.; Lunel, T.

    1997-01-01

    Dispersion and biodegradation of oil was studied in marine microcosms designed to simulate oil dispersion at sea. Dispersion was studied using both Phase Doppler Particle Analyser and a Chamber Slide technique. In both natural and artificial seawater, oil addition was observed to encourage the growth of hydrocarbon-degrading bacteria in the presence of sufficient nitrogen and phosphorus. Results showed that microorganisms enhanced oil dispersion by colonizing physically-dispersed oil droplets and preventing re-coalescence with the surface slick. The addition of dispersants increased the rate of colonization as well as the number of degraded droplets. These results suggest that stimulation of physical dispersion by chemical means increase the rate of oil biodegradation under natural conditions. 25 refs., 3 tabs., 14 figs

  10. The tropical Atlantic surface wind divergence belt and its effect on clouds

    OpenAIRE

    Y. Tubul; I. Koren; O. Altaratz

    2015-01-01

    A well-defined surface wind divergence (SWD) belt with distinct cloud properties forms over the equatorial Atlantic during the boreal summer months. This belt separates the deep convective clouds of the intertropical convergence zone (ITCZ) from the shallow marine stratocumulus cloud decks forming over the cold-water subtropical region of the southern Hadley cell. Using the QuikSCAT-SeaWinds and Aqua-MODIS instruments, we examined the large-scale spatiotemporal ...

  11. HOCl and Cl2 observations in marine air

    Directory of Open Access Journals (Sweden)

    R. Sommariva

    2011-08-01

    Full Text Available Cl atoms in the marine atmosphere may significantly impact the lifetimes of methane and other hydrocarbons. However, the existing estimates of Cl atom levels in marine air are based on indirect evidence. Here we present measurements of the Cl precursors HOCl and Cl2 in the marine boundary layer during June of 2009 at the Cape Verde Atmospheric Observatory in the eastern tropical Atlantic. These are the first measurements of tropospheric HOCl. HOCl and Cl2 levels were low in air with open ocean back trajectories, with maximum levels always below 60 and 10 ppt (pmol/mol, respectively. In air with trajectories originating over Europe, HOCl and Cl2 levels were higher, with HOCl maxima exceeding 100 ppt each day and Cl2 reaching up to 35 ppt. The increased Cl cycling associated with long distance pollutant transport over the oceans likely impacts a wide geographic area and represents a mechanism by which human activities have increased the reactivity of the marine atmosphere. Data-constrained model simulations indicate that Cl atoms account for approximately 15 % of methane destruction on days when aged polluted air arrives at the site. A photochemical model does not adequately simulate the observed abundances of HOCl and Cl2, raising the possibility of an unknown HOCl source.

  12. Quantifying the Global Marine Biogenic Nitrogen Oxides Emissions

    Science.gov (United States)

    Su, H.; Wang, S.; Lin, J.; Hao, N.; Poeschl, U.; Cheng, Y.

    2017-12-01

    Nitrogen oxides (NOx) are among the most important molecules in atmospheric chemistry and nitrogen cycle. The NOx over the ocean areas are traditionally believed to originate from the continental outflows or the inter-continental shipping emissions. By comparing the satellite observations (OMI) and global chemical transport model simulation (GEOS-Chem), we suggest that the underestimated modeled atmospheric NO2 columns over biogenic active ocean areas can be possibly attributed to the biogenic source. Nitrification and denitrification in the ocean water produces nitrites which can be further reduced to NO through microbiological processes. We further report global distributions of marine biogenic NO emissions. The new added emissions improve the agreement between satellite observations and model simulations over large areas. Our model simulations manifest that the marine biogenic NO emissions increase the atmospheric oxidative capacity and aerosol formation rate, providing a closer link between atmospheric chemistry and ocean microbiology.

  13. A Simulation Based Approach to Optimize Berth Throughput Under Uncertainty at Marine Container Terminals

    Science.gov (United States)

    Golias, Mihalis M.

    2011-01-01

    Berth scheduling is a critical function at marine container terminals and determining the best berth schedule depends on several factors including the type and function of the port, size of the port, location, nearby competition, and type of contractual agreement between the terminal and the carriers. In this paper we formulate the berth scheduling problem as a bi-objective mixed-integer problem with the objective to maximize customer satisfaction and reliability of the berth schedule under the assumption that vessel handling times are stochastic parameters following a discrete and known probability distribution. A combination of an exact algorithm, a Genetic Algorithms based heuristic and a simulation post-Pareto analysis is proposed as the solution approach to the resulting problem. Based on a number of experiments it is concluded that the proposed berth scheduling policy outperforms the berth scheduling policy where reliability is not considered.

  14. Ice nuclei in marine air: biogenic particles or dust?

    Directory of Open Access Journals (Sweden)

    S. M. Burrows

    2013-01-01

    Full Text Available Ice nuclei impact clouds, but their sources and distribution in the atmosphere are still not well known. Particularly little attention has been paid to IN sources in marine environments, although evidence from field studies suggests that IN populations in remote marine regions may be dominated by primary biogenic particles associated with sea spray. In this exploratory model study, we aim to bring attention to this long-neglected topic and identify promising target regions for future field campaigns. We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated marine biogenic immersion IN distributions and dust immersion IN distributions, we predict strong regional differences in the importance of marine biogenic IN relative to dust IN. Our analysis suggests that marine biogenic IN are most likely to play a dominant role in determining IN concentrations in near-surface-air over the Southern Ocean, so future field campaigns aimed at investigating marine biogenic IN should target that region. Climate-related changes in the abundance and emission of biogenic marine IN could affect marine cloud properties, thereby introducing previously unconsidered feedbacks that influence the hydrological cycle and the Earth's energy balance. Furthermore, marine biogenic IN may be an important aspect to consider in proposals for marine cloud brightening by artificial sea spray production.

  15. The tropical Atlantic surface wind divergence belt and its effect on clouds

    OpenAIRE

    Y. Tubul; I. Koren; O. Altaratz

    2015-01-01

    A well-defined surface wind divergence (SWD) belt with distinct cloud properties forms over the equatorial Atlantic during the boreal summer months. This belt separates the deep convective clouds of the Intertropical Convergence Zone (ITCZ) from the shallow marine stratocumulus cloud decks forming over the cold-water subtropical region of the southern branch of the Hadley cell in the Atlantic. Using the QuikSCAT-SeaWinds and Aqua-MODIS instruments, we examined the large-scal...

  16. Simulated coal spill causes mortality and growth inhibition in tropical marine organisms.

    Science.gov (United States)

    Berry, Kathryn L E; Hoogenboom, Mia O; Flores, Florita; Negri, Andrew P

    2016-05-13

    Coal is a principal fossil fuel driving economic and social development, and increases in global coal shipments have paralleled expansion of the industry. To identify the potential harm associated with chronic marine coal contamination, three taxa abundant in tropical marine ecosystems (the coral Acropora tenuis, the reef fish Acanthochromis polyacanthus and the seagrass Halodule uninervis) were exposed to five concentrations (0-275 mg coal l(-1)) of suspended coal dust (coal exposure can cause considerable lethal effects on corals, and reductions in seagrass and fish growth rates. Coral survivorship and seagrass growth rates were inversely related to increasing coal concentrations (≥38 mg coal l(-1)) and effects increased between 14 and 28 d, whereas fish growth rates were similarly depressed at all coal concentrations tested. This investigation provides novel insights into direct coal impacts on key tropical taxa for application in the assessment of risks posed by increasing coal shipments in globally threatened marine ecosystems.

  17. Complete modeling for systems of a marine diesel engine

    Science.gov (United States)

    Nahim, Hassan Moussa; Younes, Rafic; Nohra, Chadi; Ouladsine, Mustapha

    2015-03-01

    This paper presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, which allows fast predictive simulations. The whole engine system is divided into several functional blocks: cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocks are established according to engine working principles equations and experimental data collected from a marine diesel engine test bench for SIMB Company under the reference 6M26SRP1. The overall engine system dynamics is expressed as a set of simultaneous algebraic and differential equations using sub-blocks and S-Functions of Matlab/Simulink. The simulation of this model, implemented on Matlab/Simulink has been validated and can be used to obtain engine performance, pressure, temperature, efficiency, heat release, crank angle, fuel rate, emissions at different sub-blocks. The simulator will be used, in future work, to study the engine performance in faulty conditions, and can be used to assist marine engineers in fault diagnosis and estimation (FDI) as well as designers to predict the behavior of the cooling system, lubrication system, injection system, combustion, emissions, in order to optimize the dimensions of different components. This program is a platform for fault simulator, to investigate the impact on sub-blocks engine's output of changing values for faults parameters such as: faulty fuel injector, leaky cylinder, worn fuel pump, broken piston rings, a dirty turbocharger, dirty air filter, dirty air cooler, air leakage, water leakage, oil leakage and contamination, fouling of heat exchanger, pumps wear, failure of injectors (and many others).

  18. Optimized Experiment Design for Marine Systems Identification

    DEFF Research Database (Denmark)

    Blanke, M.; Knudsen, Morten

    1999-01-01

    Simulation of maneuvring and design of motion controls for marine systems require non-linear mathematical models, which often have more than one-hundred parameters. Model identification is hence an extremely difficult task. This paper discusses experiment design for marine systems identification...... and proposes a sensitivity approach to solve the practical experiment design problem. The applicability of the sensitivity approach is demonstrated on a large non-linear model of surge, sway, roll and yaw of a ship. The use of the method is illustrated for a container-ship where both model and full-scale tests...

  19. Coupled atmosphere ocean climate model simulations in the Mediterranean region: effect of a high-resolution marine model on cyclones and precipitation

    Directory of Open Access Journals (Sweden)

    A. Sanna

    2013-06-01

    Full Text Available In this study we investigate the importance of an eddy-permitting Mediterranean Sea circulation model on the simulation of atmospheric cyclones and precipitation in a climate model. This is done by analyzing results of two fully coupled GCM (general circulation models simulations, differing only for the presence/absence of an interactive marine module, at very high-resolution (~ 1/16°, for the simulation of the 3-D circulation of the Mediterranean Sea. Cyclones are tracked by applying an objective Lagrangian algorithm to the MSLP (mean sea level pressure field. On annual basis, we find a statistically significant difference in vast cyclogenesis regions (northern Adriatic, Sirte Gulf, Aegean Sea and southern Turkey and in lifetime, giving evidence of the effect of both land–sea contrast and surface heat flux intensity and spatial distribution on cyclone characteristics. Moreover, annual mean convective precipitation changes significantly in the two model climatologies as a consequence of differences in both air–sea interaction strength and frequency of cyclogenesis in the two analyzed simulations.

  20. Dynamic Modeling and Simulation of Marine Satellite Tracking Antenna Using Lagrange Method

    DEFF Research Database (Denmark)

    Wang, Yunlong; Soltani, Mohsen; Hussain, Dil muhammed Akbar

    2016-01-01

    Marine Satellite Tracking Antenna (MSTA) is a necessary device in ships for receiving satellite signals when they are sailing on the sea. This paper presents a simple methodology to obtain the dynamic equations of MSTA through Lagrange method, which is fundamental in design of modelbased controll......Marine Satellite Tracking Antenna (MSTA) is a necessary device in ships for receiving satellite signals when they are sailing on the sea. This paper presents a simple methodology to obtain the dynamic equations of MSTA through Lagrange method, which is fundamental in design of modelbased...

  1. Effective bioremediation strategy for rapid in situ cleanup of anoxic marine sediments in mesocosm oil spill simulation.

    Directory of Open Access Journals (Sweden)

    Maria eGenovese

    2014-04-01

    Full Text Available The purpose of present study was the simulation of an oil spill accompanied by burial of significant amount of petroleum hydrocarbons (PHs in coastal sediments. Approximately 1,000 kg of sediments collected in Messina harbor were spiked with Bunker C furnace fuel oil (6,500 ppm. The rapid consumption of oxygen by aerobic heterotrophs created highly reduced conditions in the sediments with subsequent recession of biodegradation rates. As follows, after three months of ageing, the anaerobic sediments did not exhibit any significant levels of biodegradation and more than 80% of added Bunker C fuel oil remained buried. Anaerobic microbial community exhibited a strong enrichment in sulfate-reducing PHs-degrading and PHs-associated Deltaproteobacteria. As an effective bioremediation strategy to clean up these contaminated sediments, we applied a Modular Slurry System (MSS allowing the containment of sediments and their physical-chemical treatment, e.g. aeration. Aeration for three months has increased the removal of main PHs contaminants up to 98%. As revealed by CARD-FISH, qPCR and 16S rRNA gene clone library analyses, addition of Bunker C fuel oil initially affected the activity of autochthonous aerobic obligate marine hydrocarbonoclastic bacteria (OMHCB, and after one month more than the third of microbial population was represented by Alcanivorax-, Cycloclasticus- and Marinobacter-related organisms. In the end of the experiment, the microbial community composition has returned to a status typically observed in pristine marine ecosystems with no detectable OMHCB present. Eco-toxicological bioassay revealed that the toxicity of sediments after treatment was substantially decreased. Thus, our studies demonstrated that petroleum-contaminated anaerobic marine sediments could efficiently be cleaned through an in situ oxygenation which stimulates their self-cleaning potential due to reawakening of allochtonous aerobic OMHCB.

  2. Investigating organic aerosol loading in the remote marine environment

    Directory of Open Access Journals (Sweden)

    K. Lapina

    2011-09-01

    Full Text Available Aerosol loading in the marine environment is investigated using aerosol composition measurements from several research ship campaigns (ICEALOT, MAP, RHaMBLe, VOCALS and OOMPH, observations of total AOD column from satellite (MODIS and ship-based instruments (Maritime Aerosol Network, MAN, and a global chemical transport model (GEOS-Chem. This work represents the most comprehensive evaluation of oceanic OM emission inventories to date, by employing aerosol composition measurements obtained from campaigns with wide spatial and temporal coverage. The model underestimates AOD over the remote ocean on average by 0.02 (21 %, compared to satellite observations, but provides an unbiased simulation of ground-based Maritime Aerosol Network (MAN observations. Comparison with cruise data demonstrates that the GEOS-Chem simulation of marine sulfate, with the mean observed values ranging between 0.22 μg m−3 and 1.34 μg m−3, is generally unbiased, however surface organic matter (OM concentrations, with the mean observed concentrations between 0.07 μg m−3 and 0.77 μg m−3, are underestimated by a factor of 2–5 for the standard model run. Addition of a sub-micron marine OM source of approximately 9 TgC yr−1 brings the model into agreement with the ship-based measurements, however this additional OM source does not explain the model underestimate of marine AOD. The model underestimate of marine AOD is therefore likely the result of a combination of satellite retrieval bias and a missing marine aerosol source (which exhibits a different spatial pattern than existing aerosol in the model.

  3. Marine N2O Emissions From Nitrification and Denitrification Constrained by Modern Observations and Projected in Multimillennial Global Warming Simulations

    Science.gov (United States)

    Battaglia, G.; Joos, F.

    2018-01-01

    Nitrous oxide (N2O) is a potent greenhouse gas (GHG) and ozone destructing agent; yet global estimates of N2O emissions are uncertain. Marine N2O stems from nitrification and denitrification processes which depend on organic matter cycling and dissolved oxygen (O2). We introduce N2O as an obligate intermediate product of denitrification and as an O2-dependent by-product from nitrification in the Bern3D ocean model. A large model ensemble is used to probabilistically constrain modern and to project marine N2O production for a low (Representative Concentration Pathway (RCP)2.6) and high GHG (RCP8.5) scenario extended to A.D. 10,000. Water column N2O and surface ocean partial pressure N2O data serve as constraints in this Bayesian framework. The constrained median for modern N2O production is 4.5 (±1σ range: 3.0 to 6.1) Tg N yr-1, where 4.5% stems from denitrification. Modeled denitrification is 65.1 (40.9 to 91.6) Tg N yr-1, well within current estimates. For high GHG forcing, N2O production decreases by 7.7% over this century due to decreasing organic matter export and remineralization. Thereafter, production increases slowly by 21% due to widespread deoxygenation and high remineralization. Deoxygenation peaks in two millennia, and the global O2 inventory is reduced by a factor of 2 compared to today. Net denitrification is responsible for 7.8% of the long-term increase in N2O production. On millennial timescales, marine N2O emissions constitute a small, positive feedback to climate change. Our simulations reveal tight coupling between the marine carbon cycle, O2, N2O, and climate.

  4. Simulated coal spill causes mortality and growth inhibition in tropical marine organisms

    Science.gov (United States)

    Berry, Kathryn L. E.; Hoogenboom, Mia O.; Flores, Florita; Negri, Andrew P.

    2016-05-01

    Coal is a principal fossil fuel driving economic and social development, and increases in global coal shipments have paralleled expansion of the industry. To identify the potential harm associated with chronic marine coal contamination, three taxa abundant in tropical marine ecosystems (the coral Acropora tenuis, the reef fish Acanthochromis polyacanthus and the seagrass Halodule uninervis) were exposed to five concentrations (0-275 mg coal l-1) of suspended coal dust (<63 μm) over 28 d. Results demonstrate that chronic coal exposure can cause considerable lethal effects on corals, and reductions in seagrass and fish growth rates. Coral survivorship and seagrass growth rates were inversely related to increasing coal concentrations (≥38 mg coal l-1) and effects increased between 14 and 28 d, whereas fish growth rates were similarly depressed at all coal concentrations tested. This investigation provides novel insights into direct coal impacts on key tropical taxa for application in the assessment of risks posed by increasing coal shipments in globally threatened marine ecosystems.

  5. CFD analysis of cascade effects in marine propellers with trailing edge modification

    DEFF Research Database (Denmark)

    Shin, Keun Woo; Andersen, Poul

    2015-01-01

    investigated intensively by viscous flow solvers, although RANS CFD is prevalent in marine industry nowadays. In the current work, the cascade effect of a marine propeller is analyzed by CFD simulations on a threedimensional propeller model with varying the number of blades. The influence of trailing......-edge configurations on the cascade effect is also investigated by simulating CFD with varying trailingedge thickness and slope. The reason why the trailingedge is handled rather than other parts of bladegeometry is that it can be modified without altering overall blade thrust significantly, because the loading...

  6. Mechanical properties of recycled concrete in marine environment.

    Science.gov (United States)

    Wang, Jianxiu; Huang, Tianrong; Liu, Xiaotian; Wu, Pengcheng; Guo, Zhiying

    2013-01-01

    Experimental work was carried out to develop information about mechanical properties of recycled concrete (RC) in marine environment. By using the seawater and dry-wet circulation to simulate the marine environment, specimens of RC were tested with different replacement percentages of 0%, 30%, and 60% after immersing in seawater for 4, 8, 12, and 16 months, respectively. Based on the analysis of the stress-strain curves (SSCs) and compressive strength, it is revealed that RC' peak value and elastic modulus decreased with the increase of replacement percentage and corroding time in marine environment. And the failure of recycled concrete was speeded up with more obvious cracks and larger angles of 65° to 85° in the surface when compared with normal concrete. Finally, the grey model (GM) with equal time intervals was constructed to investigate the law of compressive strength of recycled concrete in marine environment, and it is found that the GM is accurate and feasible for the prediction of RC compressive strength in marine environment.

  7. Simulating events

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, C; Bruzzone, L [Techint Italimpianti, Milan (Italy)

    2000-06-01

    The Petacalco Marine terminal on the Pacific coast in the harbour of Lazaro Carclenas (Michoacan) in Mexico, provides coal to the thermoelectric power plant at Pdte Plutarco Elias Calles in the port area. The plant is being converted from oil to burn coal to generate 2100 MW of power. The article describes the layout of the terminal and equipment employed in the unloading, coal stacking, coal handling areas and the receiving area at the power plant. The contractor Techint Italimpianti has developed a software system, MHATIS, for marine terminal management which is nearly complete. The discrete event simulator with its graphic interface provides a real-type decision support system for simulating changes to the terminal operations and evaluating impacts. The article describes how MHATIS is used. 7 figs.

  8. Sensitivity to deliberate sea salt seeding of marine clouds - observations and model simulations

    OpenAIRE

    Alterskjaer, K.; Kristjansson, J. E.; Seland, O.

    2012-01-01

    Sea salt seeding of marine clouds to increase their albedo is a proposed technique to counteract or slow global warming. In this study, we first investigate the susceptibility of marine clouds to sea salt injections, using observational data of cloud droplet number concentration, cloud optical depth, and liquid cloud fraction from the MODIS (Moderate Resolution Imaging Spectroradiometer) instruments on board the Aqua and Terra satellites. We then compare the derived susceptibility function to...

  9. A new physically-based quantification of marine isoprene and primary organic aerosol emissions

    Directory of Open Access Journals (Sweden)

    N. Meskhidze

    2009-07-01

    Full Text Available The global marine sources of organic carbon (OC are estimated here using a physically-based parameterization for the emission of marine isoprene and primary organic matter. The marine isoprene emission model incorporates new physical parameters such as light sensitivity of phytoplankton isoprene production and dynamic euphotic depth to simulate hourly marine isoprene emissions totaling 0.92 Tg C yr−1. Sensitivity studies using different schemes for the euphotic zone depth and ocean phytoplankton speciation produce the upper and the lower range of marine-isoprene emissions of 0.31 to 1.09 Tg C yr−1, respectively. Established relationships between sea spray fractionation of water-insoluble organic carbon (WIOC and chlorophyll-a concentration are used to estimate the total primary sources of marine sub- and super-micron OC of 2.9 and 19.4 Tg C yr−1, respectively. The consistent spatial and temporal resolution of the two emission types allow us, for the first time, to explore the relative contributions of sub- and super-micron organic matter and marine isoprene-derived secondary organic aerosol (SOA to the total OC fraction of marine aerosol. Using a fixed 3% mass yield for the conversion of isoprene to SOA, our emission simulations show minor (<0.2% contribution of marine isoprene to the total marine source of OC on a global scale. However, our model calculations also indicate that over the tropical oceanic regions (30° S to 30° N, marine isoprene SOA may contribute over 30% of the total monthly-averaged sub-micron OC fraction of marine aerosol. The estimated contribution of marine isoprene SOA to hourly-averaged sub-micron marine OC emission is even higher, approaching 50% over the vast regions of the oceans during the midday hours when isoprene emissions are highest. As it is widely believed that sub-micron OC has the potential to influence the cloud droplet activation of marine aerosols, our

  10. Simulation and Analysis of Roller Chain Drive Systems

    DEFF Research Database (Denmark)

    Pedersen, Sine Leergaard

    The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes to the syst......The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes...... mathematical models, and compare to the prior done research. Even though the model is developed at first for the use of analysing chain drive systems in marine engines, the methods can with small changes be used in general, as for e.g. chain drives in industrial machines, car engines and motorbikes. A novel...

  11. Measurement and Simulation of Pollutant Emissions from Marine Diesel Combustion Engine and Their Reduction by Ammonia Injection

    Directory of Open Access Journals (Sweden)

    Nader Larbi

    2009-01-01

    Full Text Available Taking into account the complexity and cost of a direct experimental approach, the recourse to a tool of simulation, which can also predict inaccessible information by measurement, offers an effective and fast alternative to apprehend the problem of pollutant emissions from internal combustion engines. An analytical model based on detailed chemical kinetics employed to calculate the pollutant emissions of a marine diesel engine gave satisfactory results, in general, compared to experimentally measured results. Especially the NO emission values are found to be higher than the limiting values tolerated by the International Maritime Organization (IMO. Thus, this study is undertaken in order to reduce these emissions to the maximum level. The reduction of pollutant emissions is apprehended with ammonia injection.

  12. Multisource full waveform inversion of marine streamer data with frequency selection

    KAUST Repository

    Huang, Yunsong; Schuster, Gerard T.

    2013-01-01

    Multisource migration with frequency selection is now extended to multisource full waveform inversion (FWI) of supergathers for marine streamer data. There are three advantages of this approach compared to conventional FWI for marine streamer data. 1. The multisource FWI method with frequency selection is computationally more efficient than conventional FWI. 2. A supergather requires more than an order of magnitude less storage than the the original data. 3. Frequency selection overcomes the acquisition mismatch between the observed data and the simulated multisource supergathers for marine data. This mismatch problem has prevented the efficient application of FWI to marine geometries in the space-time domain. Preliminary result of applying multisource FWI with frequency selection to a synthetic marine data set suggests it is at least four times more efficient than standard FWI.

  13. Intelligent autonomy for unmanned marine vehicles robotic control architecture based on service-oriented agents

    CERN Document Server

    Insaurralde, Carlos C

    2015-01-01

    This book presents an Intelligent Control Architecture (ICA) to enable multiple collaborating marine vehicles to autonomously carry out underwater intervention missions. The presented ICA is generic in nature but aimed at a case study where a marine surface craft and an underwater vehicle are required to work cooperatively. It is shown that they are capable of cooperating autonomously towards the execution of complex activities since they have different but complementary capabilities. The ICA implementation is verified in simulation, and validated in trials by means of a team of autonomous marine robots. This book also presents architectural details and evaluation scenarios of the ICA, results of simulations and trials from different maritime operations, and future research directions.

  14. Analysis of albedo versus cloud fraction relationships in liquid water clouds using heuristic models and large eddy simulation

    Science.gov (United States)

    Feingold, Graham; Balsells, Joseph; Glassmeier, Franziska; Yamaguchi, Takanobu; Kazil, Jan; McComiskey, Allison

    2017-07-01

    The relationship between the albedo of a cloudy scene A and cloud fraction fc is studied with the aid of heuristic models of stratocumulus and cumulus clouds. Existing work has shown that scene albedo increases monotonically with increasing cloud fraction but that the relationship varies from linear to superlinear. The reasons for these differences in functional dependence are traced to the relationship between cloud deepening and cloud widening. When clouds deepen with no significant increase in fc (e.g., in solid stratocumulus), the relationship between A and fc is linear. When clouds widen as they deepen, as in cumulus cloud fields, the relationship is superlinear. A simple heuristic model of a cumulus cloud field with a power law size distribution shows that the superlinear A-fc behavior is traced out either through random variation in cloud size distribution parameters or as the cloud field oscillates between a relative abundance of small clouds (steep slopes on a log-log plot) and a relative abundance of large clouds (flat slopes). Oscillations of this kind manifest in large eddy simulation of trade wind cumulus where the slope and intercept of the power law fit to the cloud size distribution are highly correlated. Further analysis of the large eddy model-generated cloud fields suggests that cumulus clouds grow larger and deeper as their underlying plumes aggregate; this is followed by breakup of large plumes and a tendency to smaller clouds. The cloud and thermal size distributions oscillate back and forth approximately in unison.

  15. How did Marine Isotope Stage 3 and Last Glacial Maximum climates differ? – Perspectives from equilibrium simulations

    Directory of Open Access Journals (Sweden)

    C. J. Van Meerbeeck

    2009-03-01

    Full Text Available Dansgaard-Oeschger events occurred frequently during Marine Isotope Stage 3 (MIS3, as opposed to the following MIS2 period, which included the Last Glacial Maximum (LGM. Transient climate model simulations suggest that these abrupt warming events in Greenland and the North Atlantic region are associated with a resumption of the Thermohaline Circulation (THC from a weak state during stadials to a relatively strong state during interstadials. However, those models were run with LGM, rather than MIS3 boundary conditions. To quantify the influence of different boundary conditions on the climates of MIS3 and LGM, we perform two equilibrium climate simulations with the three-dimensional earth system model LOVECLIM, one for stadial, the other for interstadial conditions. We compare them to the LGM state simulated with the same model. Both climate states are globally 2°C warmer than LGM. A striking feature of our MIS3 simulations is the enhanced Northern Hemisphere seasonality, July surface air temperatures being 4°C warmer than in LGM. Also, despite some modification in the location of North Atlantic deep water formation, deep water export to the South Atlantic remains unaffected. To study specifically the effect of orbital forcing, we perform two additional sensitivity experiments spun up from our stadial simulation. The insolation difference between MIS3 and LGM causes half of the 30–60° N July temperature anomaly (+6°C. In a third simulation additional freshwater forcing halts the Atlantic THC, yielding a much colder North Atlantic region (−7°C. Comparing our simulation with proxy data, we find that the MIS3 climate with collapsed THC mimics stadials over the North Atlantic better than both control experiments, which might crudely estimate interstadial climate. These results suggest that freshwater forcing is necessary to return climate from warm interstadials to cold stadials during MIS3. This changes our perspective, making the stadial

  16. Testing remote sensing on artificial observations: impact of drizzle and 3-D cloud structure on effective radius retrievals

    Directory of Open Access Journals (Sweden)

    T. Zinner

    2010-10-01

    Full Text Available Remote sensing of cloud effective particle size with passive sensors like the Moderate Resolution Imaging Spectroradiometer (MODIS is an important tool for cloud microphysical studies. As a measure of the radiatively relevant droplet size, effective radius can be retrieved with different combinations of visible through shortwave and midwave infrared channels. In practice, retrieved effective radii from these combinations can be quite different. This difference is perhaps indicative of different penetration depths and path lengths for the spectral reflectances used. In addition, operational liquid water cloud retrievals are based on the assumption of a relatively narrow distribution of droplet sizes; the role of larger precipitation particles in these distributions is neglected. Therefore, possible explanations for the discrepancy in some MODIS spectral size retrievals could include 3-D radiative transport effects, including sub-pixel cloud inhomogeneity, and/or the impact of drizzle formation.

    For three cloud cases the possible factors of influence are isolated and investigated in detail by the use of simulated cloud scenes and synthetic satellite data: marine boundary layer cloud scenes from large eddy simulations (LES with detailed microphysics are combined with Monte Carlo radiative transfer calculations that explicitly account for the detailed droplet size distributions as well as 3-D radiative transfer to simulate MODIS observations. The operational MODIS optical thickness and effective radius retrieval algorithm is applied to these and the results are compared to the given LES microphysics.

    We investigate two types of marine cloud situations each with and without drizzle from LES simulations: (1 a typical daytime stratocumulus deck at two times in the diurnal cycle and (2 one scene with scattered cumulus. Only small impact of drizzle formation on the retrieved domain average and on the differences between the three

  17. Lagrangian evolution of the marine boundary layer from the Cloud System Evolution in the Trades (CSET) campaign

    Science.gov (United States)

    Mohrmann, J.; Ghate, V. P.; McCoy, I. L.; Bretherton, C. S.; Wood, R.; Minnis, P.; Palikonda, R.

    2017-12-01

    The Cloud System Evolution in the Trades (CSET) field campaign took place July/August 2015 to study the evolution of clouds, precipitation, and aerosols in the stratocumulus-to-cumulus (Sc-Cu) transition region of the northeast Pacific marine boundary layer (MBL). Aircraft observations sampled across a wide range of cloud and aerosol conditions. The sampling strategy, where MBL airmasses were sampled with the NSF/NCAR Gulfstream-V (HIAPER) and resampled then at their advected location two days later, resulted in a dataset of 14 paired flights suitable for Lagrangian analysis. This analysis shows that Lagrangian coherence of long-lived species (namely CO and O3) across 48 hours are high, but that of subcloud aerosol, MBL depth, and cloud properties is limited. Geostationary satellite retrievals are compared against aircraft observations; these are combined with reanalysis data and HYSPLIT trajectories to document the Lagrangian evolution of cloud fraction, cloud droplet number concentration, liquid water path, estimated inversion strength (EIS), and MBL depth, which are used to expand upon and validate the aircraft-based analysis. Many of the trajectories sampled by the aircraft show a clear Sc-Cu transition. Although satellite cloud fraction and EIS were found to be strongly spatiotemporally correlated, changes in MBL cloud fraction along trajectories did not correlate with any measure of EIS forcing.

  18. Australia's marine virtual laboratory

    Science.gov (United States)

    Proctor, Roger; Gillibrand, Philip; Oke, Peter; Rosebrock, Uwe

    2014-05-01

    In all modelling studies of realistic scenarios, a researcher has to go through a number of steps to set up a model in order to produce a model simulation of value. The steps are generally the same, independent of the modelling system chosen. These steps include determining the time and space scales and processes of the required simulation; obtaining data for the initial set up and for input during the simulation time; obtaining observation data for validation or data assimilation; implementing scripts to run the simulation(s); and running utilities or custom-built software to extract results. These steps are time consuming and resource hungry, and have to be done every time irrespective of the simulation - the more complex the processes, the more effort is required to set up the simulation. The Australian Marine Virtual Laboratory (MARVL) is a new development in modelling frameworks for researchers in Australia. MARVL uses the TRIKE framework, a java-based control system developed by CSIRO that allows a non-specialist user configure and run a model, to automate many of the modelling preparation steps needed to bring the researcher faster to the stage of simulation and analysis. The tool is seen as enhancing the efficiency of researchers and marine managers, and is being considered as an educational aid in teaching. In MARVL we are developing a web-based open source application which provides a number of model choices and provides search and recovery of relevant observations, allowing researchers to: a) efficiently configure a range of different community ocean and wave models for any region, for any historical time period, with model specifications of their choice, through a user-friendly web application, b) access data sets to force a model and nest a model into, c) discover and assemble ocean observations from the Australian Ocean Data Network (AODN, http://portal.aodn.org.au/webportal/) in a format that is suitable for model evaluation or data assimilation, and

  19. Spaceborne Sensors Track Marine Debris Circulation in the Gulf of Mexico

    Science.gov (United States)

    Reahard, Ross; Mitchell, Brandie; Lee, Lucas; Pezold, Blaise; Brook, Chris; Mallett, Candis; Barrett, Shelby; Albin, Aaron

    2011-01-01

    Marine debris is a problem for coastal areas throughout the world, including the Gulf of Mexico. To aid the NOAA Marine Debris Program in monitoring marine debris dispersal and regulating marine debris practices, sea surface height and height anomaly data provided by the Colorado Center for Astrodynamics Research at the University of Colorado, Boulder, were utilized to help assess trash and other discarded items that routinely wash ashore in southeastern Texas, at Padre Island National Seashore. These data were generated from the NASA radar altimeter satellites TOPEX/Poseidon, Jason 1, and Jason 2, as well as the European altimeter satellites ERS-1, ERS-2 (European Remote Sensing Satellite), and ENVISAT (Environmental Satellite). Sea surface temperature data from MODIS were used to study of the dynamics of the Loop Current. Sea surface height and MODIS data analysis were used to show that warm water in the core of eddies, which periodically separate from the Loop Current, can be as high as 30 cm above the surrounding water. These eddies are known to directly transfer marine debris to the western continental shelf and the elevated area of water can be tracked using satellite radar altimeter data. Additionally, using sea surface height, geostrophic velocity, and particle path data, foretracking and backtracking simulations were created. These simulation runs demonstrated that marine debris on Padre Island National Seashore may arise from a variety of sources, such as commercial fishing/shrimping, the oil and gas industry, recreational boaters, and from rivers that empty into the Gulf of Mexico.

  20. Modeling marine surface microplastic transport to assess optimal removal locations

    OpenAIRE

    Sherman, Peter; Van Sebille, Erik

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the ...

  1. Fate of 14C-labelled compounds in marine environment

    International Nuclear Information System (INIS)

    Kale, S.P.; Raghu, K.; Sherkhane, P.D.; Murthy, N.B.K.

    1999-01-01

    Model ecosystems have played an important role in predicting environmental behavior of agrochemicals. The microcosms used in these studies generally include soil units containing usual biotic components common for that ecosystem. In present studies, scope of two such ecosystems has been extended to study the fate of 14 C-labelled pesticides in marine environment. 14 C-labelled pesticides used in these studies were chlorpyrifos, DDT and HCH. Two systems were developed in laboratory simulating marine environment to study the fate of these pesticides. The first system was developed in an all glass aquarium tank with marine sediments, seawater, clams and algae and is referred to as marine ecosystem. The second system was developed to permit the total 14 C-mass balance studies. It contained marine sediments under moist (60% water holding capacity) or flooded conditions and it is referred to as continuous flow system. Fate of 14 C-DDT was studied in marine ecosystem while degradation of 14 C-chlorpyrifos and 14 C-HCH was studied in continuous flow system. 14 C-DDT did not bioaccumulate in clams while at the end of 60 days 50% of the applied 14 C-activity was present in sediment fraction of marine ecosystem. 14 C-HCH degradation showed about 22-26% mineralization while 45-55% of the applied activity was recovered as organic volatiles. No significant bound residues were formed. 14 C-chorpyrifos underwent considerable degradation in marine environment. TCP was the major degradation product. (author)

  2. Marine Vehicle Sensor Network Architecture and Protocol Designs for Ocean Observation

    Directory of Open Access Journals (Sweden)

    Yeqiang Shu

    2012-01-01

    Full Text Available The micro-scale and meso-scale ocean dynamic processes which are nonlinear and have large variability, have a significant impact on the fisheries, natural resources, and marine climatology. A rapid, refined and sophisticated observation system is therefore needed in marine scientific research. The maneuverability and controllability of mobile sensor platforms make them a preferred choice to establish ocean observing networks, compared to the static sensor observing platform. In this study, marine vehicles are utilized as the nodes of mobile sensor networks for coverage sampling of a regional ocean area and ocean feature tracking. A synoptic analysis about marine vehicle dynamic control, multi vehicles mission assignment and path planning methods, and ocean feature tracking and observing techniques is given. Combined with the observation plan in the South China Sea, we provide an overview of the mobile sensor networks established with marine vehicles, and the corresponding simulation results.

  3. The impact of particle size, relative humidity, and sulfur dioxide on iron solubility in simulated atmospheric marine aerosols.

    Science.gov (United States)

    Cartledge, Benton T; Marcotte, Aurelie R; Herckes, Pierre; Anbar, Ariel D; Majestic, Brian J

    2015-06-16

    Iron is a limiting nutrient in about half of the world's oceans, and its most significant source is atmospheric deposition. To understand the pathways of iron solubilization during atmospheric transport, we exposed size segregated simulated marine aerosols to 5 ppm sulfur dioxide at arid (23 ± 1% relative humidity, RH) and marine (98 ± 1% RH) conditions. Relative iron solubility increased as the particle size decreased for goethite and hematite, while for magnetite, the relative solubility was similar for all of the fine size fractions (2.5-0.25 μm) investigated but higher than the coarse size fraction (10-2.5 μm). Goethite and hematite showed increased solubility at arid RH, but no difference (p > 0.05) was observed between the two humidity levels for magnetite. There was no correlation between iron solubility and exposure to SO2 in any mineral for any size fraction. X-ray absorption near edge structure (XANES) measurements showed no change in iron speciation [Fe(II) and Fe(III)] in any minerals following SO2 exposure. SEM-EDS measurements of SO2-exposed goethite revealed small amounts of sulfur uptake on the samples; however, the incorporated sulfur did not affect iron solubility. Our results show that although sulfur is incorporated into particles via gas-phase processes, changes in iron solubility also depend on other species in the aerosol.

  4. Simulating Marine New Particle Formation and Growth Using the M7 Modal Aerosol Dynamics Modal

    Directory of Open Access Journals (Sweden)

    Ciaran Monahan

    2010-01-01

    Full Text Available A modal atmospheric aerosol model (M7 is evaluated in terms of predicting marine new particle formation and growth. Simulations were carried out for three different nucleation schemes involving (1 kinetic self-nucleation of OIO (2 nucleation via OIO activation by H2SO4 and (3 nucleation via OIO activation by H2SO4 plus condensation of a low-volatility organic vapour. Peak OIO and H2SO4 vapour concentrations were both limited to 6×106 molecules cm-3 at noontime while the peak organic vapour concentration was limited to 12×106 molecules cm-3. All simulations produced significant concentrations of new particles in the Aitken mode. From a base case particle concentration of 222 cm-3 at radii >15 nm, increases in concentrations to 366 cm-3 were predicted from the OIO-OIO case, 722 cm-3 for the OIO-H2SO4 case, and 1584 cm-3 for the OIO-H2SO4 case with additional condensing organic vapours. The results indicate that open ocean new particle production is feasible for clean conditions; however, new particle production becomes most significant when an additional condensable organic vapour is available to grow the newly formed particles to larger sizes. Comparison to sectional model for a typical case study demonstrated good agreement and the validity of using the modal model.

  5. Combined observational and modeling efforts of aerosol-cloud-precipitation interactions over Southeast Asia

    Science.gov (United States)

    Loftus, Adrian; Tsay, Si-Chee; Nguyen, Xuan Anh

    2016-04-01

    Low-level stratocumulus (Sc) clouds cover more of the Earth's surface than any other cloud type rendering them critical for Earth's energy balance, primarily via reflection of solar radiation, as well as their role in the global hydrological cycle. Stratocumuli are particularly sensitive to changes in aerosol loading on both microphysical and macrophysical scales, yet the complex feedbacks involved in aerosol-cloud-precipitation interactions remain poorly understood. Moreover, research on these clouds has largely been confined to marine environments, with far fewer studies over land where major sources of anthropogenic aerosols exist. The aerosol burden over Southeast Asia (SEA) in boreal spring, attributed to biomass burning (BB), exhibits highly consistent spatiotemporal distribution patterns, with major variability due to changes in aerosol loading mediated by processes ranging from large-scale climate factors to diurnal meteorological events. Downwind from source regions, the transported BB aerosols often overlap with low-level Sc cloud decks associated with the development of the region's pre-monsoon system, providing a unique, natural laboratory for further exploring their complex micro- and macro-scale relationships. Compared to other locations worldwide, studies of springtime biomass-burning aerosols and the predominately Sc cloud systems over SEA and their ensuing interactions are underrepresented in scientific literature. Measurements of aerosol and cloud properties, whether ground-based or from satellites, generally lack information on microphysical processes; thus cloud-resolving models are often employed to simulate the underlying physical processes in aerosol-cloud-precipitation interactions. The Goddard Cumulus Ensemble (GCE) cloud model has recently been enhanced with a triple-moment (3M) bulk microphysics scheme as well as the Regional Atmospheric Modeling System (RAMS) version 6 aerosol module. Because the aerosol burden not only affects cloud

  6. Combined Observational and Modeling Efforts to Better Understand Aerosol-Cloud-Precipitation Interactions Over Land: Preliminary Results from 7-SEAS/BASELInE 2013

    Science.gov (United States)

    Loftus, Adrian M.; Tsay, Si-Chee

    2015-01-01

    This talk presents some of the detailed observations of low-level stratocumulus over northern Vietnam during 7-SEASBASELInE 2013 by SMARTLabs' ACHIEVE W-band cloud radar and other remote sensing instruments. These observations are the first of their kind for this region and will aid in ongoing studies of biomass-burning aerosol impacts on local and regional weather and climate. Preliminary results from simulations using the Goddard Cumulus Ensemble (GCE) with recently implemented triple-moment bulk microphysics to examine the sensitivity of low-level stratocumulus over land to aerosols are also presented. Recommendations for future observational activities in the 7-SEAS northern region in collaboration with international partners will also be discussed.

  7. Corrosion Behavior of Low-C Medium-Mn Steel in Simulated Marine Immersion and Splash Zone Environment

    Science.gov (United States)

    Zhang, Dazheng; Gao, Xiuhua; Su, Guanqiao; Du, Linxiu; Liu, Zhenguang; Hu, Jun

    2017-05-01

    The corrosion behavior of low-C medium-Mn steel in simulated marine immersion and splash zone environment was studied by static immersion corrosion experiment and wet-dry cyclic corrosion experiment, respectively. Corrosion rate, corrosion products, surface morphology, cross-sectional morphology, elemental distribution, potentiodynamic polarization curves and electrochemical impedance spectra were used to elucidate the corrosion behavior of low-C medium-Mn steel. The results show that corrosion rate in immersion zone is much less than that in splash zone owing to its relatively mild environment. Manganese compounds are detected in the corrosion products and only appeared in splash zone environment, which can deteriorate the protective effect of rust layer. With the extension of exposure time, corrosion products are gradually transformed into dense and thick corrosion rust from the loose and porous one in these two environments. But in splash zone environment, alloying elements of Mn appear significant enrichment in the rust layer, which decrease the corrosion resistance of the steel.

  8. Marine biology

    International Nuclear Information System (INIS)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  9. Case studies of radiation in the cloud-capped atmospheric boundary layer

    International Nuclear Information System (INIS)

    Schmetz, J.; Raschke, E.

    1983-01-01

    This review presents observations of marine stratocumulus obtained by the three research aircraft that participated in the Joint Air-Sea Interaction Project (JASIN). Detailed measurements were made of the thermodynamic, cloud physics and radiation fields for a uniform cloud sheet on 8 August 1978. These show a well mixed boundary layer with cloud liquid water contents close to their adiabatic values. The longwave and shortwave radiative components of the cloud layer energy budget were measured and good agreement was obtained between the observations and several radiation schemes. In particular, the measured cloud shortwave absorption was close to the theoretical values. Observations of shortwave fluxes made from the Falcon aircraft beneath broken stratocumulus are also shown and compared with calculations made by using a Monte Carlo model. It is concluded that the radiative cloud-cloud interactions do not play a dominant role in the bulk radiative properties of cloud fields. These are mainly determined by cloud amount and the vertical and horizontal optical depths of the clouds within the field. (author)

  10. Sensitivity study of cloud/radiation interaction using a second order turbulence radiative-convective model

    International Nuclear Information System (INIS)

    Kao, C.Y.J.; Smith, W.S.

    1993-01-01

    A high resolution one-dimensional version of a second order turbulence convective/radiative model, developed at the Los Alamos National Laboratory, was used to conduct a sensitivity study of a stratocumulus cloud deck, based on data taken at San Nicolas Island during the intensive field observation marine stratocumulus phase of the First International Satellite Cloud Climatology Program (ISCCP) Regional Experiment (FIRE IFO), conducted during July, 1987. Initial profiles for liquid water potential temperature, and total water mixing ratio were abstracted from the FIRE data. The dependence of the diurnal behavior in liquid water content, cloud top height, and cloud base height were examined for variations in subsidence rate, sea surface temperature, and initial inversion strength. The modelled diurnal variation in the column integrated liquid water agrees quite well with the observed data, for the case of low subsidence. The modelled diurnal behavior for the height of the cloud top and base show qualitative agreement with the FIRE data, although the overall height of the cloud layer is about 200 meters too high

  11. Simulated and observed trends in key variables of the Arctic marine carbon cycle

    Science.gov (United States)

    Goris, Nadine; Heinze, Christoph; Lauvset, Siv; Petrenko, Dmitry; Pozdnyakov, Dmitry; Schwinger, Jörg

    2013-04-01

    For the Arctic region, a thorough monitoring of the marine carbon cycle is important, as the general "polar amplification" of climate change also translates into the biogeochemical realm. As compared to the global ocean, the sink for human-produced CO2 is fairly small in the Arctic Ocean itself. Nevertheless, it is important to follow up this Arctic sink as a further control of the regional carbon budget and to record changes in the marine carbon cycle on the way towards a "blue Arctic". Since observations on the Arctic are rare, the EU FP7 MONARCH-A project tries to enable adequate descriptions of the status and evolution of the Arctic region Earth system components by generating time series of observation datasets and model hindcasts. In terms of the marine carbon cycle, this analysis focuses mainly on the key variables pCO2 and primary productivity. For oceanic pCO2, the comprehensive data-sets SOCAT and LDEO were combined, while measurements of atmospheric CO2 were collected from the GLOBALVIEW-CO2 data integration project. Monthly Primary Production fields were retrieved from the sensors MODIS and SeaWiFs. In order to get an overall picture of the behavior and trends of those key variables, in addition the physical-biogeochemical model MICOM-HAMOCC-M was employed. The investigation showed that both oceanic and atmospheric pCO2 are consistent variables which have a regular annual cycle and a similar behaviour all over the Arctic for both model and data. In contrast, primary production shows an irregular annual cycle in both range and form, varying over the Arctic. While a few well distributed measurement stations with continuous observations are sufficient to get a comprehensive picture for consistent variables like pCO2, it is relatively difficult and costly to get a comprehensive record of non-consistent variables. Since the provided data-set for primary production covers a relatively short time-scale, it was neither possible to confidently validate the model

  12. Development of 3-axis precise positioning seismic physical modeling system in the simulation of marine seismic exploration

    Science.gov (United States)

    Kim, D.; Shin, S.; Ha, J.; Lee, D.; Lim, Y.; Chung, W.

    2017-12-01

    Seismic physical modeling is a laboratory-scale experiment that deals with the actual and physical phenomena that may occur in the field. In seismic physical modeling, field conditions are downscaled and used. For this reason, even a small error may lead to a big error in an actual field. Accordingly, the positions of the source and the receiver must be precisely controlled in scale modeling. In this study, we have developed a seismic physical modeling system capable of precisely controlling the 3-axis position. For automatic and precise position control of an ultrasonic transducer(source and receiver) in the directions of the three axes(x, y, and z), a motor was mounted on each of the three axes. The motor can automatically and precisely control the positions with positional precision of 2''; for the x and y axes and 0.05 mm for the z axis. As it can automatically and precisely control the positions in the directions of the three axes, it has an advantage in that simulations can be carried out using the latest exploration techniques, such as OBS and Broadband Seismic. For the signal generation section, a waveform generator that can produce a maximum of two sources was used, and for the data acquisition section, which receives and stores reflected signals, an A/D converter that can receive a maximum of four signals was used. As multiple sources and receivers could be used at the same time, the system was set up in such a way that diverse exploration methods, such as single channel, multichannel, and 3-D exploration, could be realized. A computer control program based on LabVIEW was created, so that it could control the position of the transducer, determine the data acquisition parameters, and check the exploration data and progress in real time. A marine environment was simulated using a water tank 1 m wide, 1 m long, and 0.9 m high. To evaluate the performance and applicability of the seismic physical modeling system developed in this study, single channel and

  13. Evaluating commercial marine emissions and their role in air quality policy using observations and the CMAQ model

    Science.gov (United States)

    Ring, Allison M.; Canty, Timothy P.; Anderson, Daniel C.; Vinciguerra, Timothy P.; He, Hao; Goldberg, Daniel L.; Ehrman, Sheryl H.; Dickerson, Russell R.; Salawitch, Ross J.

    2018-01-01

    We investigate the representation of emissions from the largest (Class 3) commercial marine vessels (c3 Marine) within the Community Multiscale Air Quality (CMAQ) model. In present emissions inventories developed by the United States Environmental Protection Agency (EPA), c3 Marine emissions are divided into off-shore and near-shore files. Off-shore c3 Marine emissions are vertically distributed within the atmospheric column, reflecting stack-height and plume rise. Near-shore c3 Marine emissions, located close to the US shoreline, are erroneously assumed to occur only at the surface. We adjust the near-shore c3 Marine emissions inventory by vertically distributing these emissions to be consistent with the off-shore c3 Marine inventory. Additionally, we remove near-shore c3 Marine emissions that overlap with off-shore c3 Marine emissions within the EPA files. The CMAQ model generally overestimates surface ozone (O3) compared to Air Quality System (AQS) site observations, with the largest discrepancies occurring near coastal waterways. We compare modeled O3 from two CMAQ simulations for June, July, and August (JJA) 2011 to surface O3 observations from AQS sites to examine the efficacy of the c3 Marine emissions improvements. Model results at AQS sites show average maximum 8-hr surface O3 decreases up to ∼6.5 ppb along the Chesapeake Bay, and increases ∼3-4 ppb around Long Island Sound, when the adjusted c3 Marine emissions are used. Along with the c3 Marine emissions adjustments, we reduce on-road mobile NOX emissions by 50%, motivated by work from Anderson et al. 2014, and reduce the lifetime of the alkyl nitrate species group from ∼10 days to ∼1 day based on work by Canty et al. 2015, to develop the ;c3 Science; model scenario. Simulations with these adjustments further improve model representation of the atmosphere. We calculate the ratio of column formaldehyde (HCHO) and tropospheric column nitrogen dioxide (NO2) using observations from the Ozone

  14. Development of Nuclear ship Engineering Simulation SYstem (NESSY)

    International Nuclear Information System (INIS)

    Kusunoki, Tsuyoshi; Kyouya, Masahiko; Takahashi, Teruo; Kobayashi, Hideo; Ochiai, Masa-aki; Hashidate, Kouji.

    1993-11-01

    NESSY has been developed for design studies of advanced marine reactors as a part of nuclear ship research and development since 1987. Engineering simulation model of the Mutsu, which is the first nuclear ship in Japan, was completed in March of 1993. In this report we concentration on detail description of softwares for Mutsu modeling. The aims of development of NESSY are as follows; (1) Assessment and confirmation on plant performance of an advanced marine reactor in each step of nuclear ship design (2) Development of abnormality diagnosis system and operator support system as a part of enhanced automization study, and study of human interface with hardware The characteristics of NESSY are the followings. (1) Total engineering simulation system simulate simultaneously ship motions, propulsion system behavior, and nuclear plant behavior under given weather and sea conditions. (2) Models based on physical theory as far as possible. (3) The simulator has high extensibility and flexibility. It is able to apply to other reactors, as the simulation model consists of the part of basic model and the part of plant data which are easy to change. After completion of Mutsu modeling, we are planning to utilize this system as one of design tools for an advanced marine reactor. (author)

  15. Marine low cloud sensitivity to an idealized climate change : The CGILS LES intercomparison

    NARCIS (Netherlands)

    Blossey, P.N.; Bretherton, C.S.; Zhang, M.; Cheng, A.; Endo, S.; Heus, T.; Liu, Y.; Lock, A.P.; De Roode, S.R.; Xu, K.M.

    2013-01-01

    Subtropical marine low cloud sensitivity to an idealized climate change is compared in six large-eddy simulation (LES) models as part of CGILS. July cloud cover is simulated at three locations over the subtropical northeast Pacific Ocean, which are typified by cold sea surface temperatures (SSTs)

  16. Events Calendar: Smithsonian Marine Ecosystems Exhibit: Smithsonian Marine

    Science.gov (United States)

    current Smithsonian research on the plants and animals of the Indian River Lagoon and marine environments Station (SMS) at Fort Pierce Smithsonian Marine Station at Fort Pierce Website Search Box History Modeling Ecosystems Virtual Tour Facebook Instagram Twitter SMS Home › Smithsonian Marine

  17. Marine genomics

    DEFF Research Database (Denmark)

    Oliveira Ribeiro, Ângela Maria; Foote, Andrew David; Kupczok, Anne

    2017-01-01

    Marine ecosystems occupy 71% of the surface of our planet, yet we know little about their diversity. Although the inventory of species is continually increasing, as registered by the Census of Marine Life program, only about 10% of the estimated two million marine species are known. This lag......-throughput sequencing approaches have been helping to improve our knowledge of marine biodiversity, from the rich microbial biota that forms the base of the tree of life to a wealth of plant and animal species. In this review, we present an overview of the applications of genomics to the study of marine life, from...

  18. Virtual simulation of maneuvering captive tests for a surface vessel

    Directory of Open Access Journals (Sweden)

    Ahmad Hajivand

    2015-09-01

    Full Text Available Hydrodynamic derivatives or coefficients are required to predict the maneuvering characteristics of a marine vehicle. These derivatives are obtained numerically for a DTMB 5512 model ship by virtual simulating of captive model tests in a CFD environment. The computed coefficients are applied to predict the turning circle and zigzag maneuvers of the model ship. The comparison of the simulated results with the available experimental data shows a very good agreement among them. The simulations show that the CFD is precise and affordable tool at the preliminary design stage to obtain maneuverability performance of a marine vehicles.

  19. Nonlinear Control of Marine Surface Vessels

    Science.gov (United States)

    Das, Swarup; Talole, S. E.

    2018-03-01

    In the present study, a robust yaw control law design derived from nonlinear extended state observer (NESO) based nonlinear state error feedback controller (NSEFC) in conjunction with nonlinear tracking differentiator (NTD) for marine surface vessels is presented. As marine vessel operates in an environment where significant uncertainties and disturbances are present, an NESO is used to estimate the effect of the uncertainties and disturbances along with the plant states leading to a robust design through disturbance estimation and compensation. Convergence of NESO and NTD is demonstrated. The notable feature of the formulation is that to achieve robustness, accurate plant model or any characterization of the uncertainties and disturbances is not needed. Efficacy of the design is illustrated by simulation. Further, performance of the proposed design is compared with some existing controllers to showcase the effectiveness of the proposed design.

  20. The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component AM3 of the GFDL global coupled model CM3

    Science.gov (United States)

    Donner, L.J.; Wyman, B.L.; Hemler, R.S.; Horowitz, L.W.; Ming, Y.; Zhao, M.; Golaz, J.-C.; Ginoux, P.; Lin, S.-J.; Schwarzkopf, M.D.; Austin, J.; Alaka, G.; Cooke, W.F.; Delworth, T.L.; Freidenreich, S.M.; Gordon, C.T.; Griffies, S.M.; Held, I.M.; Hurlin, W.J.; Klein, S.A.; Knutson, T.R.; Langenhorst, A.R.; Lee, H.-C.; Lin, Y.; Magi, B.I.; Malyshev, S.L.; Milly, P.C.D.; Naik, V.; Nath, M.J.; Pincus, R.; Ploshay, J.J.; Ramaswamy, V.; Seman, C.J.; Shevliakova, E.; Sirutis, J.J.; Stern, W.F.; Stouffer, R.J.; Wilson, R.J.; Winton, M.; Wittenberg, A.T.; Zeng, F.

    2011-01-01

    The Geophysical Fluid Dynamics Laboratory (GFDL) has developed a coupled general circulation model (CM3) for the atmosphere, oceans, land, and sea ice. The goal of CM3 is to address emerging issues in climate change, including aerosol-cloud interactions, chemistry-climate interactions, and coupling between the troposphere and stratosphere. The model is also designed to serve as the physical system component of earth system models and models for decadal prediction in the near-term future-for example, through improved simulations in tropical land precipitation relative to earlier-generation GFDL models. This paper describes the dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component (AM3) of this model. Relative to GFDL AM2, AM3 includes new treatments of deep and shallow cumulus convection, cloud droplet activation by aerosols, subgrid variability of stratiform vertical velocities for droplet activation, and atmospheric chemistry driven by emissions with advective, convective, and turbulent transport. AM3 employs a cubed-sphere implementation of a finite-volume dynamical core and is coupled to LM3, a new land model with ecosystem dynamics and hydrology. Its horizontal resolution is approximately 200 km, and its vertical resolution ranges approximately from 70 m near the earth's surface to 1 to 1.5 km near the tropopause and 3 to 4 km in much of the stratosphere. Most basic circulation features in AM3 are simulated as realistically, or more so, as in AM2. In particular, dry biases have been reduced over South America. In coupled mode, the simulation of Arctic sea ice concentration has improved. AM3 aerosol optical depths, scattering properties, and surface clear-sky downward shortwave radiation are more realistic than in AM2. The simulation of marine stratocumulus decks remains problematic, as in AM2. The most intense 0.2% of precipitation rates occur less frequently in AM3 than observed. The last two decades of

  1. A characteristic scale in radiation fields of fractal clouds

    Energy Technology Data Exchange (ETDEWEB)

    Wiscombe, W.; Cahalan, R.; Davis, A.; Marshak, A. [Goddard Space Flight Center, Greenbelt, MD (United States)

    1996-04-01

    The wavenumber spectrum of Landsat imagery for marine stratocumulus cloud shows a scale break when plotted on a double log plot. We offer an explanation of this scale break in terms of smoothing by horizontal radiative fluxes, which is parameterized and incorporated into an improved pixel approximation. We compute the radiation fields emerging from cloud models with horizontally variable optical depth fractal models. We use comparative spectral and multifractal analysis to qualify the validity of the independent pixel approximation at the largest scales and demonstrate it`s shortcomings on the smallest scales.

  2. STEADY STATE PERFORMANCES ANALYSIS OF MODERN MARINE TWO-STROKE LOW SPEED DIESEL ENGINE USING MLP NEURAL NETWORK MODEL

    Directory of Open Access Journals (Sweden)

    Ozren Bukovac

    2016-01-01

    Full Text Available Compared to the other marine engines for ship propulsion, turbocharged two-stroke low speed diesel engines have advantages due to their high efficiency and reliability. Modern low speed ”intelligent” marine diesel engines have a flexibility in its operation due to the variable fuel injection strategy and management of the exhaust valve drive. This paper carried out verified zerodimensional numerical simulations which have been used for MLP (Multilayer Perceptron neural network predictions of marine two-stroke low speed diesel engine steady state performances. The developed MLP neural network was used for marine engine optimized operation control. The paper presents an example of achieving lowest specific fuel consumption and for minimization of the cylinder process highest temperature for reducing NOx emission. Also, the developed neural network was used to achieve optimal exhaust gases heat flow for utilization. The obtained data maps give insight into the optimal working areas of simulated marine diesel engine, depending on the selected start of the fuel injection (SOI and the time of the exhaust valve opening (EVO.

  3. Global patterns of extinction risk in marine and non-marine systems.

    Science.gov (United States)

    Webb, Thomas J; Mindel, Beth L

    2015-02-16

    Despite increasing concern over the effects of human activities on marine ecosystems, extinction in the sea remains scarce: 19-24 out of a total of >850 recorded extinctions implies a 9-fold lower marine extinction rate compared to non-marine systems. The extent of threats faced by marine systems, and their resilience to them, receive considerable attention, but the detectability of marine extinctions is less well understood. Before its extinction or threat status is recorded, a species must be both taxonomically described and then formally assessed; lower rates of either process for marine species could thus impact patterns of extinction risk, especially as species missing from taxonomic inventories may often be more vulnerable than described species. We combine data on taxonomic description with conservation assessments from the International Union for Conservation of Nature (IUCN) to test these possibilities across almost all marine and non-marine eukaryotes. We find that the 9-fold lower rate of recorded extinctions and 4-fold lower rate of ongoing extinction risk across marine species can be explained in part by differences in the proportion of species assessed by the IUCN (3% cf. 4% of non-marine species). Furthermore, once taxonomic knowledge and conservation assessments pass a threshold level, differences in extinction risk between marine and non-marine groups largely disappear. Indeed, across the best-studied taxonomic groups, there is no difference between marine and non-marine systems, with on average between 20% and 25% of species being threatened with extinction, regardless of realm. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Optimal Switching Control of Burner Setting for a Compact Marine Boiler Design

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan M.

    2010-01-01

    This paper discusses optimal control strategies for switching between different burner modes in a novel compact  marine boiler design. The ideal behaviour is defined in a performance index the minimisation of which defines an ideal trade-off between deviations in boiler pressure and water level...... approach is based on a generalisation of hysteresis control. The strategies are verified on a simulation model of the compact marine boiler for control of low/high burner load switches.  ...

  5. Effects of Biodiesel Blend on Marine Fuel Characteristics for Marine Vessels

    Directory of Open Access Journals (Sweden)

    Cherng-Yuan Lin

    2013-09-01

    Full Text Available Biodiesel produced from vegetable oils, animal fats and algae oil is a renewable, environmentally friendly and clean alternative fuel that reduces pollutants and greenhouse gas emissions in marine applications. This study investigates the influence of biodiesel blend on the characteristics of residual and distillate marine fuels. Adequate correlation equations are applied to calculate the fuel properties of the blended marine fuels with biodiesel. Residual marine fuel RMA has inferior fuel characteristics compared with distillate marine fuel DMA and biodiesel. The flash point of marine fuel RMA could be increased by 20% if blended with 20 vol% biodiesel. The sulfur content of residual marine fuel could meet the requirement of the 2008 MARPOL Annex VI Amendment by blending it with 23.0 vol% biodiesel. In addition, the kinematic viscosity of residual marine fuel could be reduced by 12.9% and the carbon residue by 23.6% if 20 vol% and 25 vol% biodiesel are used, respectively. Residual marine fuel blended with 20 vol% biodiesel decreases its lower heating value by 1.9%. Moreover, the fuel properties of residual marine fuel are found to improve more significantly with biodiesel blending than those of distillate marine fuel.

  6. Marine ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

  7. On the sensitivity of numerical weather prediction to remotely sensed marine surface wind data - A simulation study

    Science.gov (United States)

    Cane, M. A.; Cardone, V. J.; Halem, M.; Halberstam, I.

    1981-01-01

    The reported investigation has the objective to assess the potential impact on numerical weather prediction (NWP) of remotely sensed surface wind data. Other investigations conducted with similar objectives have not been satisfactory in connection with a use of procedures providing an unrealistic distribution of initial errors. In the current study, care has been taken to duplicate the actual distribution of information in the conventional observing system, thus shifting the emphasis from accuracy of the data to the data coverage. It is pointed out that this is an important consideration in assessing satellite observing systems since experience with sounder data has shown that improvements in forecasts due to satellite-derived information is due less to a general error reduction than to the ability to fill data-sparse regions. The reported study concentrates on the evaluation of the observing system simulation experimental design and on the assessment of the potential of remotely sensed marine surface wind data.

  8. Unified Description of the Mechanical Properties of Typical Marine Soil and Its Application

    Directory of Open Access Journals (Sweden)

    Yongqiang Li

    2017-01-01

    Full Text Available This study employed a modified elastoplastic constitutive model that can systematically describe the monotonic and cyclic mechanical behaviors of typical marine soils combining the subloading, normal, and superloading yield surfaces, in the seismic response analysis of three-dimensional (3D marine site. New evolution equations for stress-induced anisotropy development and the change in the overconsolidation of soils were proposed. This model can describe the unified behaviour of unsaturated soil and saturated soil using independent state variables and can uniquely describe the multiple mechanical properties of soils under general stress states, without changing the parameter values using the transform stress method. An effective stress-based, fully coupled, explicit finite element–finite difference method was established based on this model and three-phase field theory. A finite deformation analysis was presented by introducing the Green-Naghdi rate tensor. The simulation and analysis indicated that the proposed method was sufficient for simulating the seismic disaster process of 3D marine sites. The results suggested that the ground motion intensity would increase due to the local uneven complex topography and site effect and also provided the temporal and spatial distribution of landslide and collapse at the specific location of the marine site.

  9. A general-purpose process modelling framework for marine energy systems

    International Nuclear Information System (INIS)

    Dimopoulos, George G.; Georgopoulou, Chariklia A.; Stefanatos, Iason C.; Zymaris, Alexandros S.; Kakalis, Nikolaos M.P.

    2014-01-01

    Highlights: • Process modelling techniques applied in marine engineering. • Systems engineering approaches to manage the complexity of modern ship machinery. • General purpose modelling framework called COSSMOS. • Mathematical modelling of conservation equations and related chemical – transport phenomena. • Generic library of ship machinery component models. - Abstract: High fuel prices, environmental regulations and current shipping market conditions impose ships to operate in a more efficient and greener way. These drivers lead to the introduction of new technologies, fuels, and operations, increasing the complexity of modern ship energy systems. As a means to manage this complexity, in this paper we present the introduction of systems engineering methodologies in marine engineering via the development of a general-purpose process modelling framework for ships named as DNV COSSMOS. Shifting the focus from components – the standard approach in shipping- to systems, widens the space for optimal design and operation solutions. The associated computer implementation of COSSMOS is a platform that models, simulates and optimises integrated marine energy systems with respect to energy efficiency, emissions, safety/reliability and costs, under both steady-state and dynamic conditions. DNV COSSMOS can be used in assessment and optimisation of design and operation problems in existing vessels, new builds as well as new technologies. The main features and our modelling approach are presented and key capabilities are illustrated via two studies on the thermo-economic design and operation optimisation of a combined cycle system for large bulk carriers, and the transient operation simulation of an electric marine propulsion system

  10. Advancing cloud lifecycle representation in numerical models using innovative analysis methods that bridge arm observations over a breadth of scales

    Energy Technology Data Exchange (ETDEWEB)

    Tselioudis, George [Columbia Univ., New York, NY (United States)

    2016-03-04

    From its location on the subtropics-midlatitude boundary, the Azores is influenced by both the subtropical high pressure and the midlatitude baroclinic storm regimes, and therefore experiences a wide range of cloud structures, from fair-weather scenes to stratocumulus sheets to deep convective systems. This project combined three types of data sets to study cloud variability in the Azores: a satellite analysis of cloud regimes, a reanalysis characterization of storminess, and a 19-month field campaign that occurred on Graciosa Island. Combined analysis of the three data sets provides a detailed picture of cloud variability and the respective dynamic influences, with emphasis on low clouds that constitute a major uncertainty source in climate model simulations. The satellite cloud regime analysis shows that the Azores cloud distribution is similar to the mean global distribution and can therefore be used to evaluate cloud simulation in global models. Regime analysis of low clouds shows that stratocumulus decks occur under the influence of the Azores high-pressure system, while shallow cumulus clouds are sustained by cold-air outbreaks, as revealed by their preference for post-frontal environments and northwesterly flows. An evaluation of CMIP5 climate model cloud regimes over the Azores shows that all models severely underpredict shallow cumulus clouds, while most models also underpredict the occurrence of stratocumulus cloud decks. It is demonstrated that carefully selected case studies can be related through regime analysis to climatological cloud distributions, and a methodology is suggested utilizing process-resolving model simulations of individual cases to better understand cloud-dynamics interactions and attempt to explain and correct climate model cloud deficiencies.

  11. An experimental study of emission and combustion characteristics of marine diesel engine with fuel pump malfunctions

    International Nuclear Information System (INIS)

    Kowalski, Jerzy

    2014-01-01

    Presented paper shows the results of the laboratory study on the relation between the chosen malfunctions of a fuel pump and the exhaust gas composition of the marine engine. The object of research is a laboratory four-stroke diesel engine, operated at a constant speed. During the research over 50 parameters were measured with technical condition of the engine recognized as “working properly” and with simulated fuel pump malfunctions. Considered malfunctions are: fuel injection timing delay and two sets of fuel leakages in the fuel pump of one engine cylinder. The results of laboratory research confirm that fuel injection timing delay and fuel leakage in the fuel pump cause relatively small changes in thermodynamic parameters of the engine. Changes of absolute values are so small they may be omitted by marine engines operators. The measuring of the exhaust gas composition shows markedly affection with simulated malfunctions of the fuel pump. Engine operation with delayed fuel injection timing in one cylinder indicates CO 2 emission increase and NOx emission decreases. CO emission increases only at high the engine loads. Fuel leakage in the fuel pump causes changes in CO emission, the increase of CO 2 emission and the decrease of NOx emission. - Highlights: •Chosen malfunctions of the fuel injection pump of marine engine are simulated. •Changes of thermodynamic parameters of marine engine are analyzed. •Changes of CO, CO 2 and NOx emission characteristics of marine engine are analyzed. •Injection pump malfunctions take significant changes in emission characteristics

  12. Marine pollution

    International Nuclear Information System (INIS)

    Albaiges, J.

    1989-01-01

    This book covers the following topics: Transport of marine pollutants; Transformation of pollutants in the marine environment; Biological effects of marine pollutants; Sources and transport of oil pollutants in the Persian Gulf; Trace metals and hydrocarbons in Syrian coastal waters; and Techniques for analysis of trace pollutants

  13. A marine biogenic source of atmospheric ice-nucleating particles

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, T. W.; Ladino, L. A.; Alpert, Peter A.; Breckels, M. N.; Brooks, I. M.; Browse, J.; Burrows, Susannah M.; Carslaw, K. S.; Huffman, J. A.; Judd, C.; Kilthau, W. P.; Mason, R. H.; McFiggans, Gordon; Miller, L. A.; Najera, J.; Polishchuk, E. A.; Rae, S.; Schiller, C. L.; Si, M.; Vergara Temprado, J.; Whale, Thomas; Wong, J P S; Wurl, O.; Yakobi-Hancock, J. D.; Abbatt, JPD; Aller, Josephine Y.; Bertram, Allan K.; Knopf, Daniel A.; Murray, Benjamin J.

    2015-09-09

    The formation of ice in clouds is facilitated by the presence of airborne ice nucleating particles1,2. Sea spray is one of the major global sources of atmospheric particles, but it is unclear to what extent these particles are capable of nucleating ice3–11. Here we show that material in the sea surface microlayer, which is enriched in surface active organic material representative of that found in sub-micron sea- spray aerosol12–21, nucleates ice under conditions that occur in mixed-phase clouds and high-altitude ice clouds. The ice active material is likely biogenic and is less than ~0.2 ?m in size. We also show that organic material (exudate) released by a common marine diatom nucleates ice when separated from cells and propose that organic material associated with phytoplankton cell exudates are a candidate for the observed ice nucleating ability of the microlayer samples. By combining our measurements with global model simulations of marine organic aerosol, we show that ice nucleating particles of marine origin are dominant in remote marine environments, such as the Southern Ocean, the North Pacific and the North Atlantic.

  14. Modeling marine surface microplastic transport to assess optimal removal locations

    NARCIS (Netherlands)

    Sherman, Peter; Van Sebille, Erik

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics

  15. New Waves in Marine Science Symposium: Marine Animal Communication.

    Science.gov (United States)

    Allen, Betty, Comp.

    1989-01-01

    Presented are the abstracts from three research projects on marine social systems which were a part of a marine science symposium. Five sets of activities on marine animal communication are included, one each for grades K-2, 3-5, 6-8 and 9-12, and informal education. (CW)

  16. Lagrangian Observations and Modeling of Marine Larvae

    Science.gov (United States)

    Paris, Claire B.; Irisson, Jean-Olivier

    2017-04-01

    Just within the past two decades, studies on the early-life history stages of marine organisms have led to new paradigms in population dynamics. Unlike passive plant seeds that are transported by the wind or by animals, marine larvae have motor and sensory capabilities. As a result, marine larvae have a tremendous capacity to actively influence their dispersal. This is continuously revealed as we develop new techniques to observe larvae in their natural environment and begin to understand their ability to detect cues throughout ontogeny, process the information, and use it to ride ocean currents and navigate their way back home, or to a place like home. We present innovative in situ and numerical modeling approaches developed to understand the underlying mechanisms of larval transport in the ocean. We describe a novel concept of a Lagrangian platform, the Drifting In Situ Chamber (DISC), designed to observe and quantify complex larval behaviors and their interactions with the pelagic environment. We give a brief history of larval ecology research with the DISC, showing that swimming is directional in most species, guided by cues as diverse as the position of the sun or the underwater soundscape, and even that (unlike humans!) larvae orient better and swim faster when moving as a group. The observed Lagrangian behavior of individual larvae are directly implemented in the Connectivity Modeling System (CMS), an open source Lagrangian tracking application. Simulations help demonstrate the impact that larval behavior has compared to passive Lagrangian trajectories. These methodologies are already the base of exciting findings and are promising tools for documenting and simulating the behavior of other small pelagic organisms, forecasting their migration in a changing ocean.

  17. Forecasting accidental marine pollution drift: the French operational plan

    International Nuclear Information System (INIS)

    Daniel, P.; Poitevin, J.; Tiercelin, C.; Marchand, M.

    1998-01-01

    In case of accidental marine pollution, Cedre and Meteo-France, within the framework of their own public service missions, provide assistance to the French authorities in charge of pollution response. Meteo-France has developed a numerical marine oil pollution transport model, named MOTHY, designed to simulate the transport of oil in three dimensions. A hydrodynamic ocean model is linked to an oil spill model including current shear, vertical movements and fate of the oil. The use of a global atmospheric model for atmospheric forcing enables world-wide application of the model. This oil spill response system has been operational since February 1994. In case of marine pollution, Meteo-France send meteorological forecasts and oil spill drift forecasts to Cedre. In return, by its experimentations and interventions on actual pollution, Cedre is contributing to the improvement and validation of the model. New developments, exercises and training are conducted jointly. This paper summarizes the key features of MOTHY and presents some examples of model applications. (author)

  18. Marine Robot Autonomy

    CERN Document Server

    2013-01-01

    Autonomy for Marine Robots provides a timely and insightful overview of intelligent autonomy in marine robots. A brief history of this emerging field is provided, along with a discussion of the challenges unique to the underwater environment and their impact on the level of intelligent autonomy required.  Topics covered at length examine advanced frameworks, path-planning, fault tolerance, machine learning, and cooperation as relevant to marine robots that need intelligent autonomy.  This book also: Discusses and offers solutions for the unique challenges presented by more complex missions and the dynamic underwater environment when operating autonomous marine robots Includes case studies that demonstrate intelligent autonomy in marine robots to perform underwater simultaneous localization and mapping  Autonomy for Marine Robots is an ideal book for researchers and engineers interested in the field of marine robots.      

  19. Marine habitat mapping at Labuan Marine Park, Federal Territory of Labuan, Malaysia

    Science.gov (United States)

    Mustajap, Fazliana; Saleh, Ejria; Madin, John; Hamid, Shahimah Abdul

    2015-06-01

    Marine habitat mapping has recently become essential in coastal marine science research. It is one of the efforts to understand marine ecosystems, and thus to protect them. Habitat mapping is integral to marine-related industries such as fisheries, aquaculture, forestry and tourism. An assessment of marine habitat mapping was conducted at Labuan Marine Park (LMP), a marine protected area in the Federal Territory of Labuan. It is surrounded by shallow water within its islands (Kuraman, Rusukan Kecil and Rusukan Besar) with an area of 39.7 km2. The objectives of the study are to identify the substrate and types of marine habitat present within the park. Side scan sonar (SSS) (Aquascan TM) was used to determine the substrates and habitat while ground truthings were done through field observation and SCUBA diving survey. Seabed classification and marine habitat was based on NOAA's biogeography program. Three substrate types (sand, rock, silt) were identified in this area. The major marine habitats identified are corals, macro algae and small patches of sea grass. The study area is an important refuge for spawning and juvenile fish and supports the livelihood of the coastal communities on Labuan Island. Therefore, proper management is crucial in order to better maintain the marine protected area. The findings are significant and provide detailed baseline information on marine habitat for conservation, protection and future management in LMP.

  20. Nuclear ship engineering simulator

    International Nuclear Information System (INIS)

    Itoh, Yasuyoshi; Kusunoki, Tsuyoshi; Hashidate, Koji

    1991-01-01

    The nuclear ship engineering simulator, which analyzes overall system response of nuclear ship numerically, is now being developed by JAERI as an advanced design tool with the latest computer technology in software and hardware. The development of the nuclear ship engineering simulator aims at grasping characteristics of a reactor plant under the situation generated by the combination of ocean, a ship hull and a reactor. The data from various tests with the nuclear ship 'MUTSU' will be used for this simulator to modulate and verify its functions of reproducing realistic response of nuclear ship, and then the simulator will be utilized for the research and development of advanced marine reactors. (author)

  1. Analysis of I Marine Expeditionary Force Support Team Reset Operations

    Science.gov (United States)

    2013-06-01

    in the process. For the hands that have assisted in providing information and that have truly been a catalyst and a crutch for the completion...simulation-Marine Corps. Point paper . Retrieved February 20, 2013 from http://www.ehqmc.usmc.mil/org/IL/ Burton, L.D. (2005). Strategic Inventory

  2. Phylogenomics of Rhodobacteraceae reveals evolutionary adaptation to marine and non-marine habitats.

    Science.gov (United States)

    Simon, Meinhard; Scheuner, Carmen; Meier-Kolthoff, Jan P; Brinkhoff, Thorsten; Wagner-Döbler, Irene; Ulbrich, Marcus; Klenk, Hans-Peter; Schomburg, Dietmar; Petersen, Jörn; Göker, Markus

    2017-06-01

    Marine Rhodobacteraceae (Alphaproteobacteria) are key players of biogeochemical cycling, comprise up to 30% of bacterial communities in pelagic environments and are often mutualists of eukaryotes. As 'Roseobacter clade', these 'roseobacters' are assumed to be monophyletic, but non-marine Rhodobacteraceae have not yet been included in phylogenomic analyses. Therefore, we analysed 106 genome sequences, particularly emphasizing gene sampling and its effect on phylogenetic stability, and investigated relationships between marine versus non-marine habitat, evolutionary origin and genomic adaptations. Our analyses, providing no unequivocal evidence for the monophyly of roseobacters, indicate several shifts between marine and non-marine habitats that occurred independently and were accompanied by characteristic changes in genomic content of orthologs, enzymes and metabolic pathways. Non-marine Rhodobacteraceae gained high-affinity transporters to cope with much lower sulphate concentrations and lost genes related to the reduced sodium chloride and organohalogen concentrations in their habitats. Marine Rhodobacteraceae gained genes required for fucoidan desulphonation and synthesis of the plant hormone indole 3-acetic acid and the compatible solutes ectoin and carnitin. However, neither plasmid composition, even though typical for the family, nor the degree of oligotrophy shows a systematic difference between marine and non-marine Rhodobacteraceae. We suggest the operational term 'Roseobacter group' for the marine Rhodobacteraceae strains.

  3. Marine nitrogen cycle

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    ) such as the Marine nitrogen cycle The marine nitrogen cycle. ‘X’ and ‘Y’ are intra-cellular intermediates that do not accumulate in water column. (Source: Codispoti et al., 2001) Page 1 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www... and nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci. Mar., 65, 85-105, 2001. Page 2 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www.eoearth.org/article/Marine_nitrogen_cycle square6 Gruber, N.: The dynamics...

  4. Nitrogen and Oxygen Isotopic Studies of the Marine Nitrogen Cycle.

    Science.gov (United States)

    Casciotti, Karen L

    2016-01-01

    The marine nitrogen cycle is a complex web of microbially mediated reactions that control the inventory, distribution, and speciation of nitrogen in the marine environment. Because nitrogen is a major nutrient that is required by all life, its availability can control biological productivity and ecosystem structure in both surface and deep-ocean communities. Stable isotopes of nitrogen and oxygen in nitrate and nitrite have provided new insights into the rates and distributions of marine nitrogen cycle processes, especially when analyzed in combination with numerical simulations of ocean circulation and biogeochemistry. This review highlights the insights gained from dual-isotope studies applied at regional to global scales and their incorporation into oceanic biogeochemical models. These studies represent significant new advances in the use of isotopic measurements to understand the modern nitrogen cycle, with implications for the study of past ocean productivity, oxygenation, and nutrient status.

  5. Oceanic acidification affects marine carbon pump and triggers extended marine oxygen holes.

    Science.gov (United States)

    Hofmann, Matthias; Schellnhuber, Hans-Joachim

    2009-03-03

    Rising atmospheric CO(2) levels will not only drive future global mean temperatures toward values unprecedented during the whole Quaternary but will also lead to massive acidification of sea water. This constitutes by itself an anthropogenic planetary-scale perturbation that could significantly modify oceanic biogeochemical fluxes and severely damage marine biota. As a step toward the quantification of such potential impacts, we present here a simulation-model-based assessment of the respective consequences of a business-as-usual fossil-fuel-burning scenario where a total of 4,075 Petagrams of carbon is released into the atmosphere during the current millennium. In our scenario, the atmospheric pCO(2) level peaks at approximately 1,750 microatm in the year 2200 while the sea-surface pH value drops by >0.7 units on global average, inhibiting the growth of marine calcifying organisms. The study focuses on quantifying 3 major concomitant effects. The first one is a significant (climate-stabilizing) negative feedback on rising pCO(2) levels as caused by the attenuation of biogenic calcification. The second one is related to the biological carbon pump. Because mineral ballast, notably CaCO(3), is found to play a dominant role in carrying organic matter through the water column, a reduction of its export fluxes weakens the strength of the biological carbon pump. There is, however, a third effect with severe consequences: Because organic matter is oxidized in shallow waters when mineral-ballast fluxes weaken, oxygen holes (hypoxic zones) start to expand considerably in the oceans in our model world--with potentially harmful impacts on a variety of marine ecosystems.

  6. An Improved Current-Doubler Rectifier for the Marine Controlled Source Electromagnetic Transmitter

    Directory of Open Access Journals (Sweden)

    Hongxi Song

    2018-01-01

    Full Text Available High power marine controlled source electromagnetic transmitters have gained interest with applications in marine geological survey and mineral resources exploration. The direct current to direct current (DC-DC converter that is typically used in marine transmitters has some issues, as the insulated-gate bipolar transistor (IGBT tube cannot achieve zero-voltage switching (ZVS. In particular, lagging-leg switching cannot easily achieve ZVS. The conversion efficiency of the heat converter requires improvement. This paper proposes an improved current-doubler rectifier for the marine controlled source electromagnetic transmitter (ICDR-MCSET. Resonant inductance is increased and a blocking capacitor is added to the converter (DC-DC circuit, where the converter can achieve ZVS in a wide load range. This results in the effective decrease of the heating temperature and the improvement of transformation efficiency. Saber software simulation and a 20 KW electromagnetic transmitter are used to verify the results, which show that the method is feasible and effective.

  7. Simulator justifications

    International Nuclear Information System (INIS)

    Fairchild, B.T.

    1990-01-01

    For several years, the authors have been convinced by overwhelming evidence that dynamic simulators are justified for many applications where acceptance has been slow. They speculate as to why this situation has existed and list many benefits that accrue to those who use simulators for training and other purposes. This paper along may be sufficient to convince a receptive approval chain of the value of simulator ownership. It is intended primarily as an aid and supporting document for those who find it necessary to build a detailed justification for a specific simulator acquisition. The purchase of a simulator requires justification. For new military aircraft and for spacecraft, a simulator for training and performance evaluation is virtually assumed, value having been proven many times over. for commercial aircraft, safety is the overwhelming justification. For nuclear power plants, government regulations require operators to be licensed by examination on a certified simulator. For other applications, including air traffic control, biomedical, communications, electronic power transmission and distribution, emergency engineering and management, fossil power plants, gaming land vehicles, manufacturing, maintenance, marine vehicles, process plants, weapons, etc

  8. Survey of Experience Using Reinforced Concrete in Floating Marine Structures.

    Science.gov (United States)

    1983-01-01

    analyzed in several steps. The load history can be simulated by .. using load increments and independent load vectors . 4.31 NTH is not only active in...NILSEN, N., " FEILD TEST OF REINFORCEMENT CORROSION IN CONCRETE", PERFORMANCE OF CONCRETE IN MARINE ENVIRONMENT, ACI SPECIAL PUBLICATION SP-65, 1980. 136

  9. A novel approach to Lagrangian sampling of marine boundary layer cloud and aerosol in the northeast Pacific: case studies from CSET

    Science.gov (United States)

    Mohrmann, J.; Albrecht, B. A.; Bretherton, C. S.; Ghate, V. P.; Zuidema, P.; Wood, R.

    2015-12-01

    The Cloud System Evolution in the Trades (CSET) field campaign took place during July/August 2015 with the purpose of characterizing the cloud, aerosol and thermodynamic properties of the northeast Pacific marine boundary layer. One major science goal of the campaign was to observe a Lagrangian transition from thin stratocumulus (Sc) upwind near California to trade cumulus (Cu) nearer to Hawaii. Cloud properties were observed from the NSF/NCAR Gulfstream V research plane (GV) using the HIAPER Cloud Radar (HCR) and the HIAPER Spectral Resolution Lidar (HSRL), among other instrumentation. Aircraft observations were complemented by a suite of satellite-derived products. To observe a the evolution of airmasses over the course of two days, upwind regions were sampled on an outbound flight to from Sacramento, CA, to Kona, HI. The sampled airmasses were then tracked using HYSPLIT trajectories based on GFS model forecasts, and the return flight to California was planned to intercept those airmasses, using satellite observation to track cloud evolution in the interim. This approach required that trajectories were reasonably stable up to 3 days prior to final sampling, and also that forecast trajectories were in agreement with post-flight analysis and visual cloud feature tracking. The extent to which this was realised, and hence the validity of this new approach to Lagrangian airmass observation, is assessed here. We also present results showing that a Sc-Cu airmass transition was consistently observed during the CSET study using measurements from research flights and satellite.

  10. Marine Environmental History

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2012-01-01

    human society and natural marine resources. Within this broad topic, several trends and objectives are discernable. The essay argue that the so-called material marine environmental history has its main focus on trying to reconstruct the presence, development and environmental impact of past fisheries......This essay provides an overview of recent trends in the historiography of marine environmental history, a sub-field of environmental history which has grown tremendously in scope and size over the last c. 15 years. The object of marine environmental history is the changing relationship between...... and whaling operations. This ambition often entails a reconstruction also of how marine life has changed over time. The time frame rages from Paleolithicum to the present era. The field of marine environmental history also includes a more culturally oriented environmental history, which mainly has come...

  11. Economic perspective of marine reserves in fisheries: a bioeconomic model.

    Science.gov (United States)

    Chakraborty, Kunal; Kar, T K

    2012-12-01

    The present paper describes a prey-predator type fishery model with prey dispersal in a two-patch environment, one of which is a free fishing zone and other is protected zone. The objective of the paper is to maximize the net economic revenue earn from the fishery through implementing the sustainable properties of the fishery to keep the ecological balance. Biological measures are introduced to increase the understanding of the mechanisms in the bioeconomic system. The importance of marine reserve is analyzed through the obtained results of the numerical simulations of proposed model system. The results depict that reserves will be most effective when coupled with harvesting controls in adjacent fisheries. The paper also incorporates the induced cost and premium from establishing a marine protected area in a fishery. It is found that premium of marine protected area (MPA) increases with the increasing size of the reserve. Results are analyzed with the help of graphical illustrations. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Predictive Model for the Analysis of the Effects of Underwater Impulsive Sources on Marine Life

    National Research Council Canada - National Science Library

    Lazauski, Colin J

    2007-01-01

    A method is provided to predict the biological consequences to marine animals from exposure to multiple underwater impulsive sources by simulating underwater explosions over a defined period of time...

  13. Design method for marine direct drive volume control ahead actuator

    Directory of Open Access Journals (Sweden)

    WANG Haiyang

    2018-02-01

    Full Text Available [Objectives] In order to reduce the size, weight and auxiliary system configuration of marine ahead actuators, this paper proposes a kind of direct drive volume control electro-hydraulic servo ahead actuator. [Methods] The protruding and indenting control of the servo oil cylinder are realized through the forward and reverse of the bidirectional working gear pump, and the flow matching valve implements the self-locking of the ahead actuator in the target position. The mathematical model of the ahead actuator is established, and an integral separation fuzzy PID controller designed. On this basis, using AMESim software to build a simulation model of the ahead actuator, and combined with testing, this paper completes an analysis of the control strategy research and dynamic and static performance of the ahead actuator. [Results] The experimental results agree well with the simulation results and verify the feasibility of the ahead actuator's design. [Conclusions] The research results of this paper can provide valuable references for the integration and miniaturization design of marine ahead actuators.

  14. A model for microbial phosphorus cycling in bioturbated marine sediments

    DEFF Research Database (Denmark)

    Dale, Andrew W.; Boyle, R. A.; Lenton, Timothy M.

    2016-01-01

    A diagenetic model is used to simulate the diagenesis and burial of particulate organic carbon (Corg) and phosphorus (P) in marine sediments underlying anoxic versus oxic bottom waters. The latter are physically mixed by animals moving through the surface sediment (bioturbation) and ventilated...... P pump) allows preferential mineralization of the bulk Porg pool relative to Corg during both aerobic and anaerobic respiration and is consistent with the database. Results with this model show that P burial is strongly enhanced in sediments hosting fauna. Animals mix highly labile Porg away from....... The results also help to explain Corg:Porg ratios in the geological record and the persistence of Porg in ancient marine sediments. © 2016 Elsevier Ltd....

  15. A review on existing OSSEs and their implications on European marine observation requirements

    Science.gov (United States)

    She, Jun

    2017-04-01

    Marine observations are essential for understanding marine processes and improving the forecast quality, they are also expensive. It has always been an important issue to optimize sampling schemes of marine observational networks so that the value of marine observations can be maximized and the cost can be lowered. Ocean System Simulation Experiment (OSSE) is an efficient tool in assessing impacts of proposed future sampling schemes on reconstructing and forecasting the ocean and ecosystem conditions. In this study existing OSSE research results from EU projects (such as JERICO, OPEC, SANGOMA, E-AIMS and AtlantOS), institutional studies and review papers are collected and analyzed, according to regions (Arctic, Baltic, N. Atlantic, Mediterranean Sea and Black Sea) and instruments/variables. The preliminary results show that significant gaps for OSSEs in regions and instruments. Among the existing OSSEs, Argo (Bio-Argo and Deep See Argo), gliders and ferrybox are the most often investigated instruments. Although many of the OSSEs are dedicated for very specific monitoring strategies and not sufficiently comprehensive for making solid recommendations for optimizing the existing networks, the detailed findings for future marine observation requirements from the OSSEs will be summarized in the presentation. Recommendations for systematic OSSEs for optimizing European marine observation networks are also given.

  16. Modeling marine surface microplastic transport to assess optimal removal locations

    Science.gov (United States)

    Sherman, Peter; van Sebille, Erik

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the impact on ecosystems, using plankton growth as a proxy. The simulations show that the optimal removal locations are primarily located off the coast of China and in the Indonesian Archipelago for both scenarios. Our estimates show that 31% of the modeled microplastic mass can be removed by 2025 using 29 plastic collectors operating at a 45% capture efficiency from these locations, compared to only 17% when the 29 plastic collectors are moored in the North Pacific garbage patch, between Hawaii and California. The overlap of ocean surface microplastics and phytoplankton growth can be reduced by 46% at our proposed locations, while sinks in the North Pacific can only reduce the overlap by 14%. These results are an indication that oceanic plastic removal might be more effective in removing a greater microplastic mass and in reducing potential harm to marine life when closer to shore than inside the plastic accumulation zones in the centers of the gyres.

  17. Modeling marine surface microplastic transport to assess optimal removal locations

    International Nuclear Information System (INIS)

    Sherman, Peter; Van Sebille, Erik

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the impact on ecosystems, using plankton growth as a proxy. The simulations show that the optimal removal locations are primarily located off the coast of China and in the Indonesian Archipelago for both scenarios. Our estimates show that 31% of the modeled microplastic mass can be removed by 2025 using 29 plastic collectors operating at a 45% capture efficiency from these locations, compared to only 17% when the 29 plastic collectors are moored in the North Pacific garbage patch, between Hawaii and California. The overlap of ocean surface microplastics and phytoplankton growth can be reduced by 46% at our proposed locations, while sinks in the North Pacific can only reduce the overlap by 14%. These results are an indication that oceanic plastic removal might be more effective in removing a greater microplastic mass and in reducing potential harm to marine life when closer to shore than inside the plastic accumulation zones in the centers of the gyres. (letter)

  18. Single-Column Model Simulations of Subtropical Marine Boundary-Layer Cloud Transitions Under Weakening Inversions: SCM SIMULATIONS OF CLOUD TRANSITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Neggers, R. A. J. [Institute for Geophysics and Meteorology, Department of Geosciences, University of Cologne, Cologne Germany; Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Ackerman, A. S. [NASA Goddard Institute for Space Studies, New York NY USA; Angevine, W. M. [CIRES, University of Colorado, Boulder CO USA; NOAA Earth System Research Laboratory, Boulder CO USA; Bazile, E. [Météo France/CNRM, Toulouse France; Beau, I. [Météo France/ENM, Toulouse France; Blossey, P. N. [Department of Atmospheric Sciences, University of Washington, Seattle WA USA; Boutle, I. A. [Met Office, Exeter UK; de Bruijn, C. [Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Cheng, A. [NOAA Center for Weather and Climate Prediction, Environmental Modeling Center, College Park MD USA; van der Dussen, J. [Department of Geoscience and Remote Sensing, Delft University of Technology, Delft The Netherlands; Fletcher, J. [Department of Atmospheric Sciences, University of Washington, Seattle WA USA; University of Leeds, Leeds UK; Dal Gesso, S. [Institute for Geophysics and Meteorology, Department of Geosciences, University of Cologne, Cologne Germany; Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Jam, A. [Météo-France/CNRM & CNRS/IPSL/LMD, Toulouse France; Kawai, H. [Meteorological Research Institute, Climate Research Department, Japan Meteorological Agency, Tsukuba Japan; Cheedela, S. K. [Department of Atmosphere in the Earth System, Max-Planck Institut für Meteorologie, Hamburg Germany; Larson, V. E. [Department of Mathematical Sciences, University of Wisconsin-Milwaukee, Milwaukee WI USA; Lefebvre, M. -P. [Météo-France/CNRM & CNRS/IPSL/LMD, Toulouse France; Lock, A. P. [Met Office, Exeter UK; Meyer, N. R. [Department of Mathematical Sciences, University of Wisconsin-Milwaukee, Milwaukee WI USA; de Roode, S. R. [Department of Geoscience and Remote Sensing, Delft University of Technology, Delft The Netherlands; de Rooy, W. [Royal Netherlands Meteorological Institute, De Bilt The Netherlands; Sandu, I. [Section of Physical Aspects, European Centre for Medium-Range Weather Forecasts, Reading UK; Xiao, H. [University of California at Los Angeles, Los Angeles CA USA; Pacific Northwest National Laboratory, Richland WA USA; Xu, K. -M. [NASA Langley Research Centre, Hampton VI USA

    2017-10-01

    Results are presented of the GASS/EUCLIPSE single-column model inter-comparison study on the subtropical marine low-level cloud transition. A central goal is to establish the performance of state-of-the-art boundary-layer schemes for weather and climate mod- els for this cloud regime, using large-eddy simulations of the same scenes as a reference. A novelty is that the comparison covers four different cases instead of one, in order to broaden the covered parameter space. Three cases are situated in the North-Eastern Pa- cific, while one reflects conditions in the North-Eastern Atlantic. A set of variables is considered that reflects key aspects of the transition process, making use of simple met- rics to establish the model performance. Using this method some longstanding problems in low level cloud representation are identified. Considerable spread exists among models concerning the cloud amount, its vertical structure and the associated impact on radia- tive transfer. The sign and amplitude of these biases differ somewhat per case, depending on how far the transition has progressed. After cloud breakup the ensemble median ex- hibits the well-known “too few too bright” problem. The boundary layer deepening rate and its state of decoupling are both underestimated, while the representation of the thin capping cloud layer appears complicated by a lack of vertical resolution. Encouragingly, some models are successful in representing the full set of variables, in particular the verti- cal structure and diurnal cycle of the cloud layer in transition. An intriguing result is that the median of the model ensemble performs best, inspiring a new approach in subgrid pa- rameterization.

  19. Marine polar steroids

    International Nuclear Information System (INIS)

    Stonik, Valentin A

    2001-01-01

    Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

  20. Control of Non-linear Marine Cooling System

    DEFF Research Database (Denmark)

    Hansen, Michael; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2011-01-01

    We consider the problem of designing control laws for a marine cooling system used for cooling the main engine and auxiliary components aboard several classes of container vessels. We focus on achieving simple set point control for the system and do not consider compensation of the non-linearitie......-linearities, closed circuit flow dynamics or transport delays that are present in the system. Control laws are therefore designed using classical control theory and the performance of the design is illustrated through two simulation examples....

  1. An assessment of natural product discovery from marine (sensu strictu) and marine-derived fungi

    Science.gov (United States)

    Overy, David P.; Bayman, Paul; Kerr, Russell G.; Bills, Gerald F.

    2014-01-01

    The natural products community has been investigating secondary metabolites from marine fungi for several decades, but when one attempts to search for validated reports of new natural products from marine fungi, one encounters a literature saturated with reports from ‘marine-derived’ fungi. Of the 1000+ metabolites that have been characterized to date, only approximately 80 of these have been isolated from species from exclusively marine lineages. These metabolites are summarized here along with the lifestyle and habitats of their producing organisms. Furthermore, we address some of the reasons for the apparent disconnect between the stated objectives of discovering new chemistry from marine organisms and the apparent neglect of the truly exceptional obligate marine fungi. We also offer suggestions on how to reinvigorate enthusiasm for marine natural products discovery from fungi from exclusive marine lineages and highlight the need for critically assessing the role of apparently terrestrial fungi in the marine environment. PMID:25379338

  2. Evaluation for probabilistic distributions of fatigue life of marine propeller materials by using a Monte Carlo simulation

    International Nuclear Information System (INIS)

    Yoon, Han Yong; Zhang, Jian Wei

    2008-01-01

    Engineering materials have been studied and developed remarkably for a long time. But, few reports about marine propeller materials are presented. Recently, some researchers have studied the material strength of marine propellers. However, studies on parametric sensitivity and probabilistic distribution of fatigue life of propeller materials have not been made yet. In this study, a method to predict the probabilistic distributions of fatigue life of propeller materials is presented, and the influence of several parameters on the life distribution is discussed

  3. A Diagnostic PDF Cloud Scheme to Improve Subtropical Low Clouds in NCAR Community Atmosphere Model (CAM5)

    Science.gov (United States)

    Qin, Yi; Lin, Yanluan; Xu, Shiming; Ma, Hsi-Yen; Xie, Shaocheng

    2018-02-01

    Low clouds strongly impact the radiation budget of the climate system, but their simulation in most GCMs has remained a challenge, especially over the subtropical stratocumulus region. Assuming a Gaussian distribution for the subgrid-scale total water and liquid water potential temperature, a new statistical cloud scheme is proposed and tested in NCAR Community Atmospheric Model version 5 (CAM5). The subgrid-scale variance is diagnosed from the turbulent and shallow convective processes in CAM5. The approach is able to maintain the consistency between cloud fraction and cloud condensate and thus alleviates the adjustment needed in the default relative humidity-based cloud fraction scheme. Short-term forecast simulations indicate that low cloud fraction and liquid water content, including their diurnal cycle, are improved due to a proper consideration of subgrid-scale variance over the southeastern Pacific Ocean region. Compared with the default cloud scheme, the new approach produced the mean climate reasonably well with improved shortwave cloud forcing (SWCF) due to more reasonable low cloud fraction and liquid water path over regions with predominant low clouds. Meanwhile, the SWCF bias over the tropical land regions is also alleviated. Furthermore, the simulated marine boundary layer clouds with the new approach extend further offshore and agree better with observations. The new approach is able to obtain the top of atmosphere (TOA) radiation balance with a slightly alleviated double ITCZ problem in preliminary coupled simulations. This study implies that a close coupling of cloud processes with other subgrid-scale physical processes is a promising approach to improve cloud simulations.

  4. Single-Column Model Simulations of Subtropical Marine Boundary-Layer Cloud Transitions Under Weakening Inversions

    NARCIS (Netherlands)

    Neggers, R.A.J.; Ackerman, Andrew S.; Angevine, W. M.; Bazile, Eric; Beau, I.; Blossey, P. N.; Boutle, I. A.; de Bruijn, C.; cheng, A; van der Dussen, J.J.; Fletcher, J.; Dal Gesso, S.; Jam, A.; Kawai, H; Cheedela, S. K.; Larson, V. E.; Lefebvre, Marie Pierre; Lock, A. P.; Meyer, N. R.; de Roode, S.R.; de Rooy, WC; Sandu, I; Xiao, H; Xu, K. M.

    2017-01-01

    Results are presented of the GASS/EUCLIPSE single-column model intercomparison study on the subtropical marine low-level cloud transition. A central goal is to establish the performance of state-of-the-art boundary-layer schemes for weather and climate models for this cloud regime, using

  5. Carotenoids in Marine Animals

    Science.gov (United States)

    Maoka, Takashi

    2011-01-01

    Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine animal carotenoids from natural product chemistry, metabolism, food chain, and chemosystematic viewpoints, and also describe new structural carotenoids isolated from marine animals over the last decade. PMID:21566799

  6. Homogenizing Surface and Satellite Observations of Cloud. Aspects of Bias in Surface Data.

    Science.gov (United States)

    1987-11-10

    both ( pannus ), usually below fractus of bad weather, or both ( pannus ), usu- Altostratus or Nimbostratus ally below Altostratus or Nimbostratus 8 Cumulus...Stratocumulus, Stratus of an anvil; either accompanied or not by Cu- or pannus mulonimbus without anvil or fibrous upper part, by Cumulus, Stratocumulus...Stratus or pannus CL clouds invisible owing to darkness, fog, / Stratocumulus, Stratus, Cumulus and Cu- blowing dust or sand, or other similar mulonimbus

  7. Marine Biomedicine

    Science.gov (United States)

    Bang, Frederik B.

    1977-01-01

    Describes early scientific research involving marine invertebrate pathologic processes that may have led to new insights into human disease. Discussed are inquiries of Metchnikoff, Loeb, and Cantacuzene (immunolgic responses in sea stars, horseshoe crabs, and marine worms, respectively). Describes current research stemming from these early…

  8. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  9. Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data

    Energy Technology Data Exchange (ETDEWEB)

    Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

    2012-03-28

    In this DOE project the improvements to parameterization of marine primary organic matter (POM) emissions, hygroscopic properties of marine POM, marine isoprene derived secondary organic aerosol (SOA) emissions, surfactant effects, new cloud droplet activation parameterization have been implemented into Community Atmosphere Model (CAM 5.0), with a seven mode aerosol module from the Pacific Northwest National Laboratory (PNNL)'s Modal Aerosol Model (MAM7). The effects of marine aerosols derived from sea spray and ocean emitted biogenic volatile organic compounds (BVOCs) on microphysical properties of clouds were explored by conducting 10 year CAM5.0-MAM7 model simulations at a grid resolution 1.9° by 2.5° with 30 vertical layers. Model-predicted relationship between ocean physical and biological systems and the abundance of CCN in remote marine atmosphere was compared to data from the A-Train satellites (MODIS, CALIPSO, AMSR-E). Model simulations show that on average, primary and secondary organic aerosol emissions from the ocean can yield up to 20% increase in Cloud Condensation Nuclei (CCN) at 0.2% Supersaturation, and up to 5% increases in droplet number concentration of global maritime shallow clouds. Marine organics were treated as internally or externally mixed with sea salt. Changes associated with cloud properties reduced (absolute value) the model-predicted short wave cloud forcing from -1.35 Wm-2 to -0.25 Wm-2. By using different emission scenarios, and droplet activation parameterizations, this study suggests that addition of marine primary aerosols and biologically generated reactive gases makes an important difference in radiative forcing assessments. All baseline and sensitivity simulations for 2001 and 2050 using global-through-urban WRF/Chem (GU-WRF) were completed. The main objective of these simulations was to evaluate the capability of GU-WRF for an accurate representation of the global atmosphere by exploring the most accurate

  10. Characteristics and Source Apportionment of Marine Aerosols over East China Sea Using a Source-oriented Chemical Transport Model

    Science.gov (United States)

    Kang, M.; Zhang, H.; Fu, P.

    2017-12-01

    Marine aerosols exert a strong influence on global climate change and biogeochemical cycling, as oceans cover beyond 70% of the Earth's surface. However, investigations on marine aerosols are relatively limited at present due to the difficulty and inconvenience in sampling marine aerosols as well as their diverse sources. East China Sea (ECS), lying over the broad shelf of the western North Pacific, is adjacent to the Asian mainland, where continental-scale air pollution could impose a heavy load on the marine atmosphere through long-range atmospheric transport. Thus, contributions of major sources to marine aerosols need to be identified for policy makers to develop cost effective control strategies. In this work, a source-oriented version of the Community Multiscale Air Quality (CMAQ) model, which can directly track the contributions from multiple emission sources to marine aerosols, is used to investigate the contributions from power, industry, transportation, residential, biogenic and biomass burning to marine aerosols over the ECS in May and June 2014. The model simulations indicate significant spatial and temporal variations of concentrations as well as the source contributions. This study demonstrates that the Asian continent can greatly affect the marine atmosphere through long-range transport.

  11. A general purpose diagnostic technique for marine diesel engines - Application on the main propulsion and auxiliary diesel units of a marine vessel

    International Nuclear Information System (INIS)

    Lamaris, V.T.; Hountalas, D.T.

    2010-01-01

    Diesel engines are widely used in marine applications (i.e. propulsion and auxiliaries) except from a few cases where gas or steam turbines are used. This is the result of their high efficiency, power concentration and reliability compared to other compatible or alternative power sources. The proper and efficient operation of the engines (main engine and diesel generator units) in marine applications is critical, and therefore techniques or systems that determine engine current condition and detect potential faults are extremely important. Furthermore, it is advantageous when such techniques can be applied on different engine configurations and provide reliable results, because on a vessel usually exist diesel engines of different type, i.e. the main propulsion unit is a large low-speed two-stroke diesel engine while the diesel generators are four-stroke medium or high speed engines. In the present work is described and evaluated for the first time the application of an improved diagnostic technique, developed by the authors, on both the main engine and the auxiliary units of a commercial marine vessel. The diagnostic technique is based on a thermodynamic simulation model. The simulation model embedded in the technique has been modified, namely an existing two-zone model is replaced by a multi-zone one. With this modification it is avoided model constant tuning with the operating conditions. This is extremely important for the diagnostic philosophy of the proposed technique. Using data from engine shop tests, the simulation model is calibrated (i.e. model constants are determined) and the engine reference condition is obtained. The simulation model is then used to estimate the current engine condition, using field measurements (i.e. cylinder pressure measurements, periphery data, etc.). From the results it is revealed that the diagnosis method provides detailed information for the operating condition of both engines and the values of parameters that cannot be

  12. Active Marine Station Metadata

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

  13. Characterizing Marine Soundscapes.

    Science.gov (United States)

    Erbe, Christine; McCauley, Robert; Gavrilov, Alexander

    2016-01-01

    The study of marine soundscapes is becoming widespread and the amount of data collected is increasing rapidly. Data owners (typically academia, industry, government, and defense) are negotiating data sharing and generating potential for data syntheses, comparative studies, analyses of trends, and large-scale and long-term acoustic ecology research. A problem is the lack of standards and commonly agreed protocols for the recording of marine soundscapes, data analysis, and reporting that make a synthesis and comparison of results difficult. We provide a brief overview of the components in a marine soundscape, the hard- and software tools for recording and analyzing marine soundscapes, and common reporting formats.

  14. Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Stephen A.; McCoy, Renata B.; Morrison, Hugh; Ackerman, Andrew S.; Avramov, Alexander; de Boer, Gijs; Chen, Mingxuan; Cole, Jason N.S.; Del Genio, Anthony D.; Falk, Michael; Foster, Michael J.; Fridlind, Ann; Golaz, Jean-Christophe; Hashino, Tempei; Harrington, Jerry Y.; Hoose, Corinna; Khairoutdinov, Marat F.; Larson, Vincent E.; Liu, Xiaohong; Luo, Yali; McFarquhar, Greg M.; Menon, Surabi; Neggers, Roel A. J.; Park, Sungsu; Poellot, Michael R.; Schmidt, Jerome M.; Sednev, Igor; Shipway, Ben J.; Shupe, Matthew D.; Spangenberg, Douglas A.; Sud, Yogesh C.; Turner, David D.; Veron, Dana E.; von Salzen, Knut; Walker, Gregory K.; Wang, Zhien; Wolf, Audrey B.; Xie, Shaocheng; Xu, Kuan-Man; Yang, Fanglin; Zhang, Gong

    2009-02-02

    Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a cold-air outbreak mixed-phase stratocumulus cloud observed during the Atmospheric Radiation Measurement (ARM) program's Mixed-Phase Arctic Cloud Experiment. The observed cloud occurred in a well-mixed boundary layer with a cloud top temperature of -15 C. The observed average liquid water path of around 160 g m{sup -2} was about two-thirds of the adiabatic value and much greater than the average mass of ice crystal precipitation which when integrated from the surface to cloud top was around 15 g m{sup -2}. The simulations were performed by seventeen single-column models (SCMs) and nine cloud-resolving models (CRMs). While the simulated ice water path is generally consistent with the observed values, the median SCM and CRM liquid water path is a factor of three smaller than observed. Results from a sensitivity study in which models removed ice microphysics suggest that in many models the interaction between liquid and ice-phase microphysics is responsible for the large model underestimate of liquid water path. Despite this general underestimate, the simulated liquid and ice water paths of several models are consistent with the observed values. Furthermore, there is evidence that models with more sophisticated microphysics simulate liquid and ice water paths that are in better agreement with the observed values, although considerable scatter is also present. Although no single factor guarantees a good simulation, these results emphasize the need for improvement in the model representation of mixed-phase microphysics.

  15. Effect of phytoplackton-derived organic matter on the behavior of marine aerosols

    Science.gov (United States)

    Fuentes, E.; Coe, H.; McFiggans, G.; Green, D.

    2009-04-01

    The presence of significant concentrations of organic material in marine aerosols has been appreciated for several decades; however, only recently has significant progress been made towards demonstrating that this organic content is biogenically formed. Biogenic organics of placktonic life origin are incorporated in marine aerosol composition as a result of bubble bursting/breaking waves mechanisms that occur at the ocean surface. The presence of organic surfactants in the marine aerosol composition might have a significant impact on the properties of the generated aerosols by affecting the particles surface tension and solution balance properties. Nevertheless, it remains uncertain the role of such organics on the physical-chemical behavior of marine aerosols. In this work an experimental study was performed in order to determine the influence of biogenic marine organic compounds on the size distribution, hygroscopicity and cloud-nucleating properties of marine aerosols. For the experimental study a laboratory water recirculation system (bubble tank), designed for the simulation of bubble-burst aerosol formation, was used as marine aerosol generator. The bubble spectra produced by such system was characterized by means of an optical bubble measuring device (BMS) and it was found to be consistent with oceanic bubble spectra properties. Seawater proxy solutions were prepared from laboratory biologically-synthesized exudates produced by oceanic representative algal species and introduced in the tank for the generation of marine aerosol by bubble bursting. Two experimental methods were employed for seawater proxies preparation: the formation of surface monolayers from the biogenic surfactants extracted by a solid phase extraction technique (monolayer method) and the mixing of the exudates in the sea salt water bulk (bulk mixing method). Particle size distribution, hygroscopicity and cloud condensation nuclei experiments for different monolayers, and exudate mixtures

  16. Using random walk models to simulate the vertical distribution of particles in a turbulent water column

    DEFF Research Database (Denmark)

    Visser, Andre

    1997-01-01

    Random walk simulation has the potential to be an extremely powerful tool in the investigation of turbulence in environmental processes. However, care must be taken in applying such simulations to the motion of particles in turbulent marine systems where turbulent diffusivity is commonly spatially...... are incorrect, and a simple technique that can properly simulate turbulent diffusion in the marine environment is discussed...... non-uniform. The problems associated with this nonuniformity are far from negligible and have been recognised for quite some time. However, incorrect implementations continue to appear in the Literature. In this note computer simulations are presented to illustrate how and why these implementations...

  17. Carotenoids in Marine Animals

    OpenAIRE

    Maoka, Takashi

    2011-01-01

    Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine a...

  18. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high ... or by any means without permission in writing from the copyright holder. ..... Journal of Chemical Engineering Research and Design 82 ... Indian Ocean Marine Science Association Technical.

  19. Marine animal stings or bites

    Science.gov (United States)

    Stings - marine animals; Bites - marine animals ... Things you can do to prevent a marine animal sting or bite include: Swim near a lifeguard. Observe posted signs that may warn of danger from jellyfish or other hazardous marine life. ...

  20. Implementing and Innovating Marine Monitoring Approaches for Assessing Marine Environmental Status

    KAUST Repository

    Danovaro, Roberto; Carugati, Laura; Berzano, Marco; Cahill, Abigail E.; Carvalho, Susana; Chenuil, Anne; Corinaldesi, Cinzia; Cristina, Sonia; David, Romain; Dell'Anno, Antonio; Dzhembekova, Nina; Garcé s, Esther; Gasol, Joseph M.; Goela, Priscila; Fé ral, Jean-Pierre; Ferrera, Isabel; Forster, Rodney M.; Kurekin, Andrey A.; Rastelli, Eugenio; Marinova, Veselka; Miller, Peter I.; Moncheva, Snejana; Newton, Alice; Pearman, John K.; Pitois, Sophie G.; Reñ é , Albert; Rodrí guez-Ezpeleta, Naiara; Saggiomo, Vincenzo; Simis, Stefan G. H.; Stefanova, Kremena; Wilson, Christian; Lo Martire, Marco; Greco, Silvestro; Cochrane, Sabine K. J.; Mangoni, Olga; Borja, Angel

    2016-01-01

    Marine environmental monitoring has tended to focus on site-specific methods of investigation. These traditional methods have low spatial and temporal resolution and are relatively labor intensive per unit area/time that they cover. To implement the Marine Strategy Framework Directive (MSFD), European Member States are required to improve marine monitoring and design monitoring networks. This can be achieved by developing and testing innovative and cost-effective monitoring systems, as well as indicators of environmental status. Here, we present several recently developed methodologies and technologies to improve marine biodiversity indicators and monitoring methods. The innovative tools are discussed concerning the technologies presently utilized as well as the advantages and disadvantages of their use in routine monitoring. In particular, the present analysis focuses on: (i) molecular approaches, including microarray, Real Time quantitative PCR (qPCR), and metagenetic (metabarcoding) tools; (ii) optical (remote) sensing and acoustic methods; and (iii) in situ monitoring instruments. We also discuss their applications in marine monitoring within the MSFD through the analysis of case studies in order to evaluate their potential utilization in future routine marine monitoring. We show that these recently-developed technologies can present clear advantages in accuracy, efficiency and cost.

  1. Implementing and Innovating Marine Monitoring Approaches for Assessing Marine Environmental Status

    KAUST Repository

    Danovaro, Roberto

    2016-11-23

    Marine environmental monitoring has tended to focus on site-specific methods of investigation. These traditional methods have low spatial and temporal resolution and are relatively labor intensive per unit area/time that they cover. To implement the Marine Strategy Framework Directive (MSFD), European Member States are required to improve marine monitoring and design monitoring networks. This can be achieved by developing and testing innovative and cost-effective monitoring systems, as well as indicators of environmental status. Here, we present several recently developed methodologies and technologies to improve marine biodiversity indicators and monitoring methods. The innovative tools are discussed concerning the technologies presently utilized as well as the advantages and disadvantages of their use in routine monitoring. In particular, the present analysis focuses on: (i) molecular approaches, including microarray, Real Time quantitative PCR (qPCR), and metagenetic (metabarcoding) tools; (ii) optical (remote) sensing and acoustic methods; and (iii) in situ monitoring instruments. We also discuss their applications in marine monitoring within the MSFD through the analysis of case studies in order to evaluate their potential utilization in future routine marine monitoring. We show that these recently-developed technologies can present clear advantages in accuracy, efficiency and cost.

  2. Is chloroplastic class IIA aldolase a marine enzyme?

    Science.gov (United States)

    Miyasaka, Hitoshi; Ogata, Takeru; Tanaka, Satoshi; Ohama, Takeshi; Kano, Sanae; Kazuhiro, Fujiwara; Hayashi, Shuhei; Yamamoto, Shinjiro; Takahashi, Hiro; Matsuura, Hideyuki; Hirata, Kazumasa

    2016-01-01

    Expressed sequence tag analyses revealed that two marine Chlorophyceae green algae, Chlamydomonas sp. W80 and Chlamydomonas sp. HS5, contain genes coding for chloroplastic class IIA aldolase (fructose-1, 6-bisphosphate aldolase: FBA). These genes show robust monophyly with those of the marine Prasinophyceae algae genera Micromonas, Ostreococcus and Bathycoccus, indicating that the acquisition of this gene through horizontal gene transfer by an ancestor of the green algal lineage occurred prior to the divergence of the core chlorophytes (Chlorophyceae and Trebouxiophyceae) and the prasinophytes. The absence of this gene in some freshwater chlorophytes, such as Chlamydomonas reinhardtii, Volvox carteri, Chlorella vulgaris, Chlorella variabilis and Coccomyxa subellipsoidea, can therefore be explained by the loss of this gene somewhere in the evolutionary process. Our survey on the distribution of this gene in genomic and transcriptome databases suggests that this gene occurs almost exclusively in marine algae, with a few exceptions, and as such, we propose that chloroplastic class IIA FBA is a marine environment-adapted enzyme. This hypothesis was also experimentally tested using Chlamydomonas W80, for which we found that the transcript levels of this gene to be significantly lower under low-salt (that is, simulated terrestrial) conditions. Expression analyses of transcriptome data for two algae, Prymnesium parvum and Emiliania huxleyi, taken from the Sequence Read Archive database also indicated that the expression of this gene under terrestrial conditions (low NaCl and low sulfate) is significantly downregulated. Thus, these experimental and transcriptome data provide support for our hypothesis. PMID:27058504

  3. Aerosol-cloud interactions in Arctic mixed-phase stratocumulus

    Science.gov (United States)

    Solomon, A.

    2017-12-01

    Reliable climate projections require realistic simulations of Arctic cloud feedbacks. Of particular importance is accurately simulating Arctic mixed-phase stratocumuli (AMPS), which are ubiquitous and play an important role in regional climate due to their impact on the surface energy budget and atmospheric boundary layer structure through cloud-driven turbulence, radiative forcing, and precipitation. AMPS are challenging to model due to uncertainties in ice microphysical processes that determine phase partitioning between ice and radiatively important cloud liquid water. Since temperatures in AMPS are too warm for homogenous ice nucleation, ice must form through heterogeneous nucleation. In this presentation we discuss a relatively unexplored source of ice production-recycling of ice nuclei in regions of ice subsaturation. AMPS frequently have ice-subsaturated air near the cloud-driven mixed-layer base where falling ice crystals can sublimate, leaving behind IN. This study provides an idealized framework to understand feedbacks between dynamics and microphysics that maintain phase-partitioning in AMPS. In addition, the results of this study provide insight into the mechanisms and feedbacks that may maintain cloud ice in AMPS even when entrainment of IN at the mixed-layer boundaries is weak.

  4. Otters, Marine

    Science.gov (United States)

    Estes, James A.; Bodkin, James L.; Ben-David, M.; Perrin, William F.; Würsing, Bernd; Thewissen, J.G.M.

    2009-01-01

    The otters (Mustelidae; Lutrinae) provide an exceptional perspective into the evolution of marine living by mammals. Most extant marine mammals (e.g. the cetaceans, pinnipeds, and sirenians) have been so highly modified by long periods of selection for life in the sea that they bear little resemblance to their terrestrial ancestors. Marine otters, in contrast, are more recent expatriates from freshwater habitats and some species still live in both environments. Contrasts among species within the otters, and among the otters, terrestrial mammals, and the more highly adapted pinnipeds and cetaceans provide powerful insights into mammalian adaptations to life in the sea (Estes, 1989). Among the marine mammals, sea otters (Enhydra lutris, Fig. 1) provide the clearest understanding of consumer-induced effects on ecosystem function. This is due in part to opportunities provided by history and in part to the relative ease with which shallow coastal systems where sea otters live can be observed and studied. Although more difficult to study than sea otters, other otter species reveal the connectivity among the marine, freshwater, and terrestrial systems. These three qualities of the otters – their comparative biology, their role as predators, and their role as agents of ecosystem connectivity – are what make them interesting to marine mammalogy.The following account provides a broad overview of the comparative biology and ecology of the otters, with particular emphasis on those species or populations that live in the sea. Sea otters are features prominently, in part because they live exclusively in the sea whereas other otters have obligate associations with freshwater and terrestrial environments (Kenyon, 1969; Riedman and Estes, 1990).

  5. Understanding the tropical warm temperature bias simulated by climate models

    Science.gov (United States)

    Brient, Florent; Schneider, Tapio

    2017-04-01

    The state-of-the-art coupled general circulation models have difficulties in representing the observed spatial pattern of surface tempertaure. A majority of them suffers a warm bias in the tropical subsiding regions located over the eastern parts of oceans. These regions are usually covered by low-level clouds scattered from stratus along the coasts to more vertically developed shallow cumulus farther from them. Models usually fail to represent accurately this transition. Here we investigate physical drivers of this warm bias in CMIP5 models through a near-surface energy budget perspective. We show that overestimated solar insolation due to a lack of stratocumulus mostly explains the warm bias. This bias also arises partly from inter-model differences in surface fluxes that could be traced to differences in near-surface relative humidity and air-sea temperature gradient. We investigate the role of the atmosphere in driving surface biases by comparing historical and atmopsheric (AMIP) experiments. We show that some differences in boundary-layer characteristics, mostly those related to cloud fraction and relative humidity, are already present in AMIP experiments and may be the drivers of coupled biases. This gives insights in how models can be improved for better simulations of the tropical climate.

  6. Evaluation of Simulated Marine Aerosol Production Using the WaveWatchIII Prognostic Wave Model Coupled to the Community Atmosphere Model within the Community Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Long, M. S. [Harvard Univ., Cambridge, MA (United States). School of Engineering and Applied Sciences; Keene, William C. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Environmental Sciences; Zhang, J. [Univ. of North Dakota, Grand Forks, ND (United States). Dept. of Atmospheric Sciences; Reichl, B. [Univ. of Rhode Island, Narragansett, RI (United States). Graduate School of Oceanography; Shi, Y. [Univ. of North Dakota, Grand Forks, ND (United States). Dept. of Atmospheric Sciences; Hara, T. [Univ. of Rhode Island, Narragansett, RI (United States). Graduate School of Oceanography; Reid, J. S. [Naval Research Lab. (NRL), Monterey, CA (United States); Fox-Kemper, B. [Brown Univ., Providence, RI (United States). Earth, Environmental and Planetary Sciences; Craig, A. P. [National Center for Atmospheric Research, Boulder, CO (United States); Erickson, D. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division; Ginis, I. [Univ. of Rhode Island, Narragansett, RI (United States). Graduate School of Oceanography; Webb, A. [Univ. of Tokyo (Japan). Dept. of Ocean Technology, Policy, and Environment

    2016-11-08

    Primary marine aerosol (PMA) is emitted into the atmosphere via breaking wind waves on the ocean surface. Most parameterizations of PMA emissions use 10-meter wind speed as a proxy for wave action. This investigation coupled the 3rd generation prognostic WAVEWATCH-III wind-wave model within a coupled Earth system model (ESM) to drive PMA production using wave energy dissipation rate – analogous to whitecapping – in place of 10-meter wind speed. The wind speed parameterization did not capture basin-scale variability in relations between wind and wave fields. Overall, the wave parameterization did not improve comparison between simulated versus measured AOD or Na+, thus highlighting large remaining uncertainties in model physics. Results confirm the efficacy of prognostic wind-wave models for air-sea exchange studies coupled with laboratory- and field-based characterizations of the primary physical drivers of PMA production. No discernible correlations were evident between simulated PMA fields and observed chlorophyll or sea surface temperature.

  7. Seashore marine table quiz

    OpenAIRE

    Institute, Marine

    2013-01-01

    Develop an increasing awareness of plants and animals that live in local marine environments including the seashore, seas and oceans of Ireland. After learning all about the seashore and other marine related lessons, this quiz can be used to evaluate the student’s knowledge of the marine related living things and natural environments. The table quiz can be used as a guide, highlighting facts about the marine environment and some of the animals that live there.

  8. Observations of regional and local variability in the optical properties of maritime clouds

    Energy Technology Data Exchange (ETDEWEB)

    White, A.B. [Univ. of Colorado at Boulder/National Oceanic and Atmospheric Administration, Boulder, CO (United States); Fairall, C.W. [Environmental Technology Lab., Boulder, CO (United States)

    1996-04-01

    White and Fairall (1995) calculated the optical properties of the marine boundary layer (MBL) clouds observed during the Atlantic Stratocumulus Transition Experiment (ASTEX) and compared their results with the results obtained by Fairall et al. for the MBL clouds observed during the First International Satellite Climatology Program (ISSCP) Regional Experiment (FIRE). They found a factor of two difference in the optical depth versus liquid water relationship that applies to the clouds observed in each case. In the present study, we present evidence to support this difference. We also investigate the local variability exhibited in the ASTEX optical properties using measurements of the boundary layer aerosol concentration.

  9. NRL tethered balloon measurements at San Nicolas Island during FIRE IFO 1987

    Science.gov (United States)

    Gerber, Hermann; Gathman, Stuart; James, Jeffrey; Smith, Mike; Consterdine, Ian; Brandeki, Scott

    1990-01-01

    An overview is given of the tethered balloon measurements made during the First ISCCP Regional Experiment (FIRE) marine stratocumulus intensive field observations (IFO) at San Nicolas Island in 1987. The instrument utilized on the balloon flights, the 17 flights over a 10 day period, the state of the data analysis, and some preliminary results are described. A goal of the measurements with the Naval Research Laboratory (NRL) balloon was to give a unique and greatly improved look at the microphysics of the clear and cloud-topped boundary layer. For this goal, collocated measurements were made of turbulence, aerosol, cloud particles, and meteorology. Two new instruments which were expected to make significant contributions to this effort were the saturation hygrometer, capable of measuring 95 percent less than RH 105 percent (with an accuracy of 0.05 percent near 100 percent) and used for the first time in clouds; and the forward scatter meter which gives in situ LWC measurements at more than 10 Hz. The data set, while unfortunately only partially simultaneous with the bulk of the FIRE stratocumulus observations, is unique and worthwhile in its own right. For the first time accurate RH measurements near 100 percent have been made in-cloud; although, the use of the saturation hygrometer reflected a learning experience which will result is substantially better performance the next time. These measurements were made in conjunction with other microphysical measurements such as aerosol and cloud droplet spectra, and perhaps most important of all, they were all collocated with bivane turbulence measurements thus permitting flux calculations. Thus the analysis of this data set, which consisted of about 50 percent stratocumulus cases including increasing and decreasing partial cloud cover, should lead to new insights on the physical mechanisms which drive the boundary-layer/cloud/turbulence system.

  10. Marine bioacoustics and technology: The new world of marine acoustic ecology

    Science.gov (United States)

    Hastings, Mardi C.; Au, Whitlow W. L.

    2012-11-01

    Marine animals use sound for communication, navigation, predator avoidance, and prey detection. Thus the rise in acoustic energy associated with increasing human activity in the ocean has potential to impact the lives of marine animals. Thirty years ago marine bioacoustics primarily focused on evaluating effects of human-generated sound on hearing and behavior by testing captive animals and visually observing wild animals. Since that time rapidly changing electronic and computing technologies have yielded three tools that revolutionized how bioacousticians study marine animals. These tools are (1) portable systems for measuring electrophysiological auditory evoked potentials, (2) miniaturized tags equipped with positioning sensors and acoustic recording devices for continuous short-term acoustical observation rather than intermittent visual observation, and (3) passive acoustic monitoring (PAM) systems for remote long-term acoustic observations at specific locations. The beauty of these breakthroughs is their direct applicability to wild animals in natural habitats rather than only to animals held in captivity. Hearing capabilities of many wild species including polar bears, beaked whales, and reef fishes have now been assessed by measuring their auditory evoked potentials. Miniaturized acoustic tags temporarily attached to an animal to record its movements and acoustic environment have revealed the acoustic foraging behavior of sperm and beaked whales. Now tags are being adapted to fishes in effort to understand their behavior in the presence of noise. Moving and static PAM systems automatically detect and characterize biological and physical features of an ocean area without adding any acoustic energy to the environment. PAM is becoming a powerful technique for understanding and managing marine habitats. This paper will review the influence of these transformative tools on the knowledge base of marine bioacoustics and elucidation of relationships between marine

  11. Marine Jurisdiction Boundaries

    Data.gov (United States)

    Department of Homeland Security — The NOAA Coastal Services Center's Marine Jurisdiction dataset was created to assist in marine spatial planning and offshore alternative energy sitting. This is a...

  12. Analysis of the Effect of a Marine Energy Farm to Protect a Biosphere Reserve

    Directory of Open Access Journals (Sweden)

    Rusu Eugen

    2016-01-01

    Full Text Available Sacalin Peninsula in the Black Sea is a new land located south of the Saint George branch of the Danube. Since 1938 this area became a biosphere reserve since many rare species of animals and plants are to be found there. The generation of this new peninsula is due to the sedimentary process induced by the Danube River outflow and it was started more than 150 years ago. In the winter of 2013 this environment was seriously affected by some very strong storms putting in real danger this ecosystem. From this perspective, the objective of the present work is to evaluate the protection that might be offered to this area by a marine energy farm that would be deployed in front of the peninsula. In order to assess the coastal protection offered by the proposed solution, simulations with the SWAN (Simulating Waves Nearshore wave model have been performed for the most relevant storm patterns. The results show that a marine energy farm can provide a real sheltering effect to the ecological reserve. Such approach seems to be also economically viable since this coastal environment represents a real hot spot in the Black Sea from the point of view of marine energy resources.

  13. 75 FR 68605 - Marine Mammals

    Science.gov (United States)

    2010-11-08

    ...-XX23 Marine Mammals AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... permit to conduct research on marine mammals. ADDRESSES: The permit and related documents are available... applicant. The requested permit has been issued under the authority of the Marine Mammal Protection Act of...

  14. 77 FR 2512 - Marine Mammals

    Science.gov (United States)

    2012-01-18

    ...-XA905 Marine Mammals AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... Dorian Houser, Ph.D., National Marine Mammal Foundation, 2240 Shelter Island Drive, 200, San Diego, CA... subject permit is requested under the authority of the Marine Mammal Protection Act of 1972, as amended...

  15. 77 FR 17033 - Taking and Importing Marine Mammals: Taking Marine Mammals Incidental to Navy's Training...

    Science.gov (United States)

    2012-03-23

    ... take marine mammals by harassment incidental to its training activities at the Gulf of Mexico (GOMEX... Importing Marine Mammals: Taking Marine Mammals Incidental to Navy's Training Activities at the Gulf of Mexico Range Complex AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric...

  16. A Back-to-Back 2L-3L Grid Integration of a Marine Current Energy Converter

    Directory of Open Access Journals (Sweden)

    Senad Apelfröjd

    2015-01-01

    Full Text Available The paper proposes a back-to-back 2L-3L grid connection topology for a marine current energy converter. A prototype marine current energy converter has been deployed by a research group at Uppsala University. The concept behind the prototype revolves around a fixed pitch vertical axis turbine directly connected to a permanent magnet synchronous generator (PMSG. The proposed grid connection system utilizes a well known and proven two level voltage source converter generator-side combined with a three-level cascaded H-bridge (CHB multilevel converter grid-side. The multilevel converter brings benefits in terms of efficiency, power quality and DC-link utilization. The system is here presented for a single marine current energy converter but can easily be scaled up for clusters of marine current energy converters. Control schemes for both grid-side and generator-side voltage source converters are presented. The start-up, steady state and dynamic performance of the marine current energy converter are investigated and simulation results are presented in this paper.

  17. Marine biodiversity and fishery sustainability.

    Science.gov (United States)

    Shao, Kwang-Tsao

    2009-01-01

    Marine fish is one of the most important sources of animal protein for human use, especially in developing countries with coastlines. Marine fishery is also an important industry in many countries. Fifty years ago, many people believed that the ocean was so vast and so resilient that there was no way the marine environment could be changed, nor could marine fishery resources be depleted. Half a century later, we all agree that the depletion of fishery resources is happening mainly due to anthropogenic factors such as overfishing, habitat destruction, pollution, invasive species introduction, and climate change. Since overfishing can cause chain reactions that decrease marine biodiversity drastically, there will be no seafood left after 40 years if we take no action. The most effective ways to reverse this downward trend and restore fishery resources are to promote fishery conservation, establish marine-protected areas, adopt ecosystem-based management, and implement a "precautionary principle." Additionally, enhancing public awareness of marine conservation, which includes eco-labeling, fishery ban or enclosure, slow fishing, and MPA (marine protected areas) enforcement is important and effective. In this paper, we use Taiwan as an example to discuss the problems facing marine biodiversity and sustainable fisheries.

  18. Marine electrical practice

    CERN Document Server

    Watson, G O

    1991-01-01

    Marine Engineering Series: Marine Electrical Practice, Sixth Edition focuses on changes in the marine industry, including the application of programmable electronic systems, generators, and motors. The publication first ponders on insulation and temperature ratings of equipment, protection and discrimination, and AC generators. Discussions focus on construction, shaft-drive generators, effect of unbalanced loading, subtransient and transient reactance, protection discrimination, fault current, measurement of ambient air temperature, and basis of machine ratings. The text then examines AC switc

  19. Mariners Weather Log

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Mariners Weather Log (MWL) is a publication containing articles, news and information about marine weather events and phenomena, worldwide environmental impact...

  20. Marine Genomics: A clearing-house for genomic and transcriptomic data of marine organisms

    Directory of Open Access Journals (Sweden)

    Trent Harold F

    2005-03-01

    Full Text Available Abstract Background The Marine Genomics project is a functional genomics initiative developed to provide a pipeline for the curation of Expressed Sequence Tags (ESTs and gene expression microarray data for marine organisms. It provides a unique clearing-house for marine specific EST and microarray data and is currently available at http://www.marinegenomics.org. Description The Marine Genomics pipeline automates the processing, maintenance, storage and analysis of EST and microarray data for an increasing number of marine species. It currently contains 19 species databases (over 46,000 EST sequences that are maintained by registered users from local and remote locations in Europe and South America in addition to the USA. A collection of analysis tools are implemented. These include a pipeline upload tool for EST FASTA file, sequence trace file and microarray data, an annotative text search, automated sequence trimming, sequence quality control (QA/QC editing, sequence BLAST capabilities and a tool for interactive submission to GenBank. Another feature of this resource is the integration with a scientific computing analysis environment implemented by MATLAB. Conclusion The conglomeration of multiple marine organisms with integrated analysis tools enables users to focus on the comprehensive descriptions of transcriptomic responses to typical marine stresses. This cross species data comparison and integration enables users to contain their research within a marine-oriented data management and analysis environment.

  1. 76 FR 76949 - Marine Mammals

    Science.gov (United States)

    2011-12-09

    ...-XR52 Marine Mammals AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric.... 14534 is requested under the authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216...

  2. 77 FR 14352 - Marine Mammals

    Science.gov (United States)

    2012-03-09

    ...-XB065 Marine Mammals AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216), the Endangered Species Act of 1973, as amended...

  3. 75 FR 77616 - Marine Mammals

    Science.gov (United States)

    2010-12-13

    .... 14334] Marine Mammals AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216), the Endangered Species Act of 1973, as amended...

  4. Molecular dynamics simulations of the Nip7 proteins from the marine deep- and shallow-water Pyrococcus species.

    Science.gov (United States)

    Medvedev, Kirill E; Alemasov, Nikolay A; Vorobjev, Yuri N; Boldyreva, Elena V; Kolchanov, Nikolay A; Afonnikov, Dmitry A

    2014-10-15

    The identification of the mechanisms of adaptation of protein structures to extreme environmental conditions is a challenging task of structural biology. We performed molecular dynamics (MD) simulations of the Nip7 protein involved in RNA processing from the shallow-water (P. furiosus) and the deep-water (P. abyssi) marine hyperthermophylic archaea at different temperatures (300 and 373 K) and pressures (0.1, 50 and 100 MPa). The aim was to disclose similarities and differences between the deep- and shallow-sea protein models at different temperatures and pressures. The current results demonstrate that the 3D models of the two proteins at all the examined values of pressures and temperatures are compact, stable and similar to the known crystal structure of the P. abyssi Nip7. The structural deviations and fluctuations in the polypeptide chain during the MD simulations were the most pronounced in the loop regions, their magnitude being larger for the C-terminal domain in both proteins. A number of highly mobile segments the protein globule presumably involved in protein-protein interactions were identified. Regions of the polypeptide chain with significant difference in conformational dynamics between the deep- and shallow-water proteins were identified. The results of our analysis demonstrated that in the examined ranges of temperatures and pressures, increase in temperature has a stronger effect on change in the dynamic properties of the protein globule than the increase in pressure. The conformational changes of both the deep- and shallow-sea protein models under increasing temperature and pressure are non-uniform. Our current results indicate that amino acid substitutions between shallow- and deep-water proteins only slightly affect overall stability of two proteins. Rather, they may affect the interactions of the Nip7 protein with its protein or RNA partners.

  5. MarineCadastre.gov

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — MarineCadastre.gov is a marine information system that provides authoritative ocean data, offshore planning tools, and technical support to the offshore renewable...

  6. Research on H2 speed governor for diesel engine of marine power station

    Science.gov (United States)

    Huang, Man-Lei

    2007-09-01

    The frequency stability of a marine power system is determined by the dynamic characteristic of the diesel engine speed regulation system in a marine power station. In order to reduce the effect of load disturbances and improve the dynamic precision of a diesel engine speed governor, a controller was designed for a diesel engine speed regulation system using H2 control theory. This transforms the specifications of the system into a standard H2 control problem. Firstly, the mathematical model of a diesel engine speed regulation system using an H2 speed governor is presented. To counter external disturbances and model uncertainty, the design of an H2 speed governor rests on the problem of mixed sensitivity. Computer simulation verified that the H2 speed governor improves the dynamic precision of a system and the ability to adapt to load disturbances, thus enhancing the frequency stability of marine power systems.

  7. Marine actinobacteria associated with marine organisms and their potentials in producing pharmaceutical natural products.

    Science.gov (United States)

    Valliappan, Karuppiah; Sun, Wei; Li, Zhiyong

    2014-09-01

    Actinobacteria are ubiquitous in the marine environment, playing an important ecological role in the recycling of refractory biomaterials and producing novel natural products with pharmic applications. Actinobacteria have been detected or isolated from the marine creatures such as sponges, corals, mollusks, ascidians, seaweeds, and seagrass. Marine organism-associated actinobacterial 16S rRNA gene sequences, i.e., 3,003 sequences, deposited in the NCBI database clearly revealed enormous numbers of actinobacteria associated with marine organisms. For example, RDP classification of these sequences showed that 112 and 62 actinobacterial genera were associated with the sponges and corals, respectively. In most cases, it is expected that these actinobacteria protect the host against pathogens by producing bioactive compounds. Natural products investigation and functional gene screening of the actinobacteria associated with the marine organisms revealed that they can synthesize numerous natural products including polyketides, isoprenoids, phenazines, peptides, indolocarbazoles, sterols, and others. These compounds showed anticancer, antimicrobial, antiparasitic, neurological, antioxidant, and anti-HIV activities. Therefore, marine organism-associated actinobacteria represent an important resource for marine drugs. It is an upcoming field of research to search for novel actinobacteria and pharmaceutical natural products from actinobacteria associated with the marine organisms. In this review, we attempt to summarize the present knowledge on the diversity and natural products production of actinobacteria associated with the marine organisms, based on the publications from 1991 to 2013.

  8. Calibrated Blade-Element/Momentum Theory Aerodynamic Model of the MARIN Stock Wind Turbine: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Goupee, A.; Kimball, R.; de Ridder, E. J.; Helder, J.; Robertson, A.; Jonkman, J.

    2015-04-02

    In this paper, a calibrated blade-element/momentum theory aerodynamic model of the MARIN stock wind turbine is developed and documented. The model is created using open-source software and calibrated to closely emulate experimental data obtained by the DeepCwind Consortium using a genetic algorithm optimization routine. The provided model will be useful for those interested in validating interested in validating floating wind turbine numerical simulators that rely on experiments utilizing the MARIN stock wind turbine—for example, the International Energy Agency Wind Task 30’s Offshore Code Comparison Collaboration Continued, with Correlation project.

  9. 76 FR 41463 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Science.gov (United States)

    2011-07-14

    ... requirements, many marine animals may need to remain in areas where they are exposed to chronic stimuli... Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Marine... Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS). ACTION: Notice; proposed...

  10. Marine environmental monitoring programmes in South Africa: a review

    Directory of Open Access Journals (Sweden)

    H. M. Verheye

    2010-01-01

    Full Text Available South Africa uniquely lies at the junction of two major currents, the Agulhas and the Benguela. The waters overlying the continental shelf exhibit exceptionally high short-, medium- and long-term (days to inter-decadal variability compared with most other shelf areas, and strongly contrasting oceanographic conditions are observed on the east and west coasts. South Africa is rich in fisheries resources and associated environmental data collected over more than a century. The South African marine scientific community has a history of multidisciplinary studies of marine foodwebs, from the driving forces such as wind, currents and solar heating, to the top predators, with the development of kelp bed, sub-tidal reefs and estuarine ecosystem studies in the 1970s; the Benguela Ecology Programme, which ran through four successive five-year stages, focused on the pelagic marine resources. Various approaches have been used to observe the continental shelf at different time and space scales, including: macroscale but frequent satellite imagery, mesoscale environmental and fishery surveys, dedicated crossshelf transects in key areas, measurements of dynamic processes, use of moored buoys and coastal weather stations, and integrated monitoring approaches, including modelling and simulation studies. Between 30 and 50 years of comprehensive marine data now exist, which are proving useful in the application of an ecosystem approach to fisheries monitoring and management, as decadal changes become discernible. These observations need to continue; even though the single-species stock assessment and operational management procedures have not yet formally used environmental factors for fisheries management advice, they help us to understand the factors affecting fish population fluctuations and early life histories and to identify large-scale regime shifts where marine trophic structure and functioning alter to a new state.

  11. [Analysis on sustainable development of marine economy in Jiangsu Province based on marine ecological footprint correction model].

    Science.gov (United States)

    Yang, Shan; Wang, Yu-ting

    2011-03-01

    Based on the theories and methods of ecological footprint, the concept of marine ecological footprint was proposed. According to the characteristics of marine environment in Jiangsu Province, five sub-models of marine ecological footprints, including fishery, transporation, marine engineering construction, marine energy, and tidal flat, were constructed. The equilibrium factors of the five marine types were determined by using improved entropy method, and the marine footprints and capacities in Jiangsu Province from 2000 to 2008 were calculated and analyzed. In 2000-2008, the marine ecology footprint per capita in Jiangsu Province increased nearly seven times, from 36.90 hm2 to 252.94 hm2, and the ecological capacity per capita grew steadily, from 105.01 hm2 to 185.49 hm2. In 2000, the marine environment in the Province was in a state of ecological surplus, and the marine economy was in a weak sustainable development state. Since 2004, the marine ecological environment deteriorated sharply, with ecological deficit up to 109660.5 hm2, and the sustainability of marine economy declined. The high ecological footprint of fishery was the main reason for the ecological deficit. Tidal flat was the important reserve resource for the sustainable development of marine economy in Jiangsu Province.

  12. Marine Education Knowledge Inventory.

    Science.gov (United States)

    Hounshell, Paul B.; Hampton, Carolyn

    This 35-item, multiple-choice Marine Education Knowledge Inventory was developed for use in upper elementary/middle schools to measure a student's knowledge of marine science. Content of test items is drawn from oceanography, ecology, earth science, navigation, and the biological sciences (focusing on marine animals). Steps in the construction of…

  13. Factors controlling the compositional variations among the marine and non-marine black shales from Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Baioumy, Hassan M. [Central Metallurgical R and D Institute, PO Box 87 Helwan, Cairo (Egypt); Ismael, Ismael S. [Faculty of Science, Suez Canal University, Suez (Egypt)

    2010-07-01

    Non-marine (Jurassic) and marine (Cretaceous) black shales from Egypt were subjected to mineralogical and geochemical analyses to examine the controlling factors of their compositional variations. Non-marine black shales are composed of kaolinite and quartz with traces of gypsum, illite, calcite, feldspars, and dolomite, while marine black shales from the Red Sea area are composed of smectite, kaolinite, quartz, calcite, and dolomite with traces of feldspars. Abu Tartur marine black shales are composed of smectite and quartz with traces of feldspars and gypsum. Non-marine black shales show considerably higher Nb, Ta, Hf, and Zr contents and Th/Yb ratios compared to the marine black shales. On the other hand, marine black shales show considerably higher Cr, V, and Zn contents with positive correlations between these elements and organic carbon (C{sub org.}){sub .} Red Sea black shales have higher Ni/Co, V/Cr, and U/Al ratios. Chondrite normalized values of the medium and heavy rare earth elements (MREEs and HREEs, respectively) are higher in the non-marine black shales compared to the marine black shales. Pyrite from non-marine black shales is characterized by high positive {delta}{sup 34}S isotope values (average of + 9.3 permille). Pyrite from Red Sea black shales has low negative {delta}{sup 34}S values (average of -16.7 permille), pyrite from black shales of the lower member of the Duwi Formation has positive {delta}{sup 34}S values (average of 5.8 permille), while pyrite from marine black shales of the middle member has negative {delta}{sup 34}S values (average of -0.83 permille). Source area composition, weathering conditions, depositional environments, and type of organic matter are considered to be the probable controlling factors of these variations. The more felsic constituents in the source area of non-marine black shales is responsible for the relatively high Nb, Ta, Hf, and Zr contents and Th/Yb ratio. Relatively high kaolinite contents and Chemical

  14. On the spread of changes in marine low cloud cover in climate model simulations of the 21st century

    Science.gov (United States)

    Qu, Xin; Hall, Alex; Klein, Stephen A.; Caldwell, Peter M.

    2014-05-01

    In 36 climate change simulations associated with phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5), changes in marine low cloud cover (LCC) exhibit a large spread, and may be either positive or negative. Here we develop a heuristic model to understand the source of the spread. The model's premise is that simulated LCC changes can be interpreted as a linear combination of contributions from factors shaping the clouds' large-scale environment. We focus primarily on two factors—the strength of the inversion capping the atmospheric boundary layer (measured by the estimated inversion strength, EIS) and sea surface temperature (SST). For a given global model, the respective contributions of EIS and SST are computed. This is done by multiplying (1) the current-climate's sensitivity of LCC to EIS or SST variations, by (2) the climate-change signal in EIS or SST. The remaining LCC changes are then attributed to changes in greenhouse gas and aerosol concentrations, and other environmental factors. The heuristic model is remarkably skillful. Its SST term dominates, accounting for nearly two-thirds of the intermodel variance of LCC changes in CMIP3 models, and about half in CMIP5 models. Of the two factors governing the SST term (the SST increase and the sensitivity of LCC to SST perturbations), the SST sensitivity drives the spread in the SST term and hence the spread in the overall LCC changes. This sensitivity varies a great deal from model to model and is strongly linked to the types of cloud and boundary layer parameterizations used in the models. EIS and SST sensitivities are also estimated using observational cloud and meteorological data. The observed sensitivities are generally consistent with the majority of models as well as expectations from prior research. Based on the observed sensitivities and the relative magnitudes of simulated EIS and SST changes (which we argue are also physically reasonable), the heuristic model predicts LCC

  15. 78 FR 30870 - Nomination of Existing Marine Protected Areas to the National System of Marine Protected Areas

    Science.gov (United States)

    2013-05-23

    ... Marine Protected Areas to the National System of Marine Protected Areas AGENCY: National Marine Protected...) invited federal, state, commonwealth, and territorial marine protected area (MPA) programs with... of Marine Protected Areas of the United States (Framework), developed in response to Executive Order...

  16. Status of 137Cs contamination in marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model two years simulation following the Fukushima accident

    International Nuclear Information System (INIS)

    Tateda, Yutaka; Tsumune, Daisuke; Tsubono, Takaki; Misumi, Kazuhiro; Yamada, Masatoshi; Kanda, Jota; Ishimaru, Takashi

    2016-01-01

    Radiocesium ( 134 Cs and 137 Cs) released into the Fukushima coastal environment was transferred to marine biota inhabiting the Pacific Ocean coastal waters of eastern Japan. Though the levels in most of the edible marine species decreased overtime, radiocesium concentrations in some fishes were still remained higher than the Japanese regulatory limit for seafood products. In this study, a dynamic food chain transfer model was applied to reconstruct 137 Cs levels in olive flounder by adopting the radiocesium concentrations in small demersal fish which constitute an important fraction of the diet of the olive flounder particularly inhabiting area near Fukushima. In addition, 137 Cs levels in slime flounder were also simulated using reported radiocesium concentrations in some prey organisms. The simulated results from Onahama on the southern border of the Fukushima coastline, and at Choshi the southernmost point where the contaminated water mass was transported by the Oyashio current, were assessed in order to identify what can be explained from present information, and what remains to be clarified three years after the Fukushima Dai-ichi nuclear power plant (1FNPP) accident. As a result, the observed 137 Cs concentrations in planktivorous fish and their predator fish could be explained by the theoretically-derived simulated levels. On the other hand, the slow 137 Cs depuration in slime flounder can be attributed to uptake from unknown sources for which the uptake fluxes were of a similar magnitude as the excretion fluxes. Since the reported 137 Cs concentrations in benthic invertebrates off Onahama were higher than the simulated values, radiocesium transfer from these benthic detritivorous invertebrates to slime flounder via ingestion was suggested as a cause for the observed slow depuration of 137 Cs in demersal fish off southern Fukushima. Furthermore, the slower depuration in the demersal fish likely required an additional source of 137 Cs, i.e. contaminated

  17. Viral tracer studies indicate contamination of marine waters by sewage disposal practices in key largo, Florida.

    Science.gov (United States)

    Paul, J H; Rose, J B; Brown, J; Shinn, E A; Miller, S; Farrah, S R

    1995-06-01

    Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys.

  18. Removing vessels from the water for biofouling treatment has the potential to introduce mobile non-indigenous marine species.

    Science.gov (United States)

    Coutts, Ashley D M; Valentine, Joseph P; Edgar, Graham J; Davey, Adam; Burgess-Wilson, Bella

    2010-09-01

    Vessels found contaminated with biofouling non-indigenous marine species are predominantly removed from the water and treated in vessel maintenance facilities (i.e., slipways, travel lifts and dry-docks). Using pre-fouled settlement plates to simulate a vessel's removal from the water for treatment, we demonstrate that a range of mobile organisms (including non-indigenous marine species) may be lost to the marine environment as a consequence of this process. We also determined that different levels of biofouling (primary, secondary and tertiary) and emersion durations (0.5, 5 and 15 min) affected the abundance and composition of mobile taxa lost to the marine environment. Primary biofouling plates lost 3.2% of total animals, secondary plates lost 19.8% and tertiary plates lost 8.2%, while hanging duration had only minor effects. The results suggest that removing vessels contaminated with biofouling non-indigenous marine species from the water for treatment may not be as biosecure as is currently recognised. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Plastics in the Marine Environment.

    Science.gov (United States)

    Law, Kara Lavender

    2017-01-03

    Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence-albeit limited-of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

  20. Plastics in the Marine Environment

    Science.gov (United States)

    Law, Kara Lavender

    2017-01-01

    Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence—albeit limited—of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

  1. Biosurfactants from marine microorganisms

    Directory of Open Access Journals (Sweden)

    Suppasil Maneerat

    2005-11-01

    Full Text Available Biosurfactants are the surface-active molecules synthesized by microorganisms. With the advantage of environmental compatibility, the demand for biosurfactants has been steadily increasing and may eventually replace their chemically synthesized counterparts. Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the bioremediation of the sea polluted by crude oil. This review describes screening of biosurfactant-producing microorganisms, the determination of biosurfactant activity as well as the recovery of marine surfactant. The uses of marine biosurfactants for bioremediation are also discussed.

  2. Simulations, serious games and their applications

    CERN Document Server

    Goei, Sui

    2014-01-01

    This book presents the state of the art technology in Serious Games which is driven extensive by applications and research in simulation. The topics in this book include: (1) Fashion simulation; (2) Chinese calligraphy ink diffusion simulation; (3) Rehabilitation (4) Long vehicle turning simulation; (5) Marine traffic conflict control; (6) CNC simulation; (7) Special needs education. The book also addresses the fundamental issues in Simulation and Serious Games such as rapid collision detection, game engines or game development platforms. The target audience for this book includes scientists, engineers and practitioners involved in the field of Serious Games and Simulation. The major part of this book comprises of papers presented at the 2012 Asia-Europe Workshop on Serious Games and Simulation held in Nanyang Technological University, Singapore (May 9, 2012).  All the contributions have been peer reviewed and by scientific committee members with report about quality, content and originality.

  3. VIIRS Marine Isoprene Product and Initial Applications

    Science.gov (United States)

    Tong, D.; Wang, M.; Wang, B.; Pan, L.; Lee, P.; Goldberg, M.

    2017-12-01

    Isoprene is a reactive biogenic hydrocarbon that affects atmospheric chemistry, aerosol loading, and cloud formation. We have developed a marine isoprene emission algorithm based on ocean color data from the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP). and global meteorology simulated by NOAA Global Forecasting System (GFS). This algorithm is implemented to generate a multi-year data record (2012-2015) of marine isoprene. The product was validated using historic ocean observations of marine isoprene, as well as in-situ data collected during two recent cruises (SPACES/OASIS in 2014 and ASTRA-OMZ in 2015). Result shows that the VIIRS product has captured the seasonal and spatial variability of global oceanic isoprene emission, which is controlled by a myriad of biological and environmental variables including chlorophyll-a concentration, phytoplankton functional types, seawater light attenuation rate, wind speed, and sea surface temperature. The VIIRS isoprene emission displays considerable seasonal and spatial variations, with peaks in spring over seawater abundant with nutrient inputs. Year to year variations are small, with the annual global emissions ranging from 0.20 to 0.25 Tg C/yr. This new dataset provides the first multi-year observations of global isoprene emissions that can be used to study a variety of environmental issues such as coastal air quality, global aerosol, and cloud formation. Some "early-adopter" applications of this product are briefly discussed.

  4. 75 FR 54095 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Seismic Survey in...

    Science.gov (United States)

    2010-09-03

    ... Marine Mammals Incidental to Specified Activities; Low- Energy Marine Seismic Survey in the Eastern... low-energy marine seismic survey. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is... funding provided by the National Science Foundation, a low-energy marine seismic survey. NMFS reviewed SIO...

  5. Linking Marine Ecosystem Services to the North Sea’s Energy Fields in Transnational Marine Spatial Planning

    Directory of Open Access Journals (Sweden)

    Christina Vogel

    2018-06-01

    Full Text Available Marine spatial planning temporally and spatially allocates marine resources to different users. The ecosystem approach aims at optimising the social and economic benefits people derive from marine resources while preserving the ecosystem’s health. Marine ecosystem services are defined as the benefits people obtain from marine ecosystems. The aim of this study is to determine which interrelations between marine ecosystem services and the marine energy industry can be identified for use in transnational marine spatial planning exemplified in the North Sea region. As the North Sea is one of the busiest seas worldwide, the risk of impairing the ecosystems through anthropogenic pressures is high. Drawing on a literature-based review, 23 marine ecosystem services provided by the North Sea region were defined and linked to seven offshore energy fields comprising oil and natural gas, wind, tides and currents, waves, salinity gradients, algal biomass, and geothermal heat. The interactions were divided into four categories: dependence, impact, bidirectional, or no interaction. Oil and natural gas, as well as algae biomass, are the fields with the most relations with marine ecosystem services while waves and salinity gradients exhibit the least. Some marine ecosystem services (Conditions for Infrastructure, Regulation of Water Flows, and Cognitive Development are needed for all fields; Recreation and Tourism, Aesthetic and Cultural Perceptions and Traditions, Cognitive Development, and Sea Scape are impacted by all fields. The results of this research provide an improved basis for an ecosystem approach in transnational marine spatial planning.

  6. A paleoclimatic simulation of the Late Permian greenhouse world and its consequences

    Energy Technology Data Exchange (ETDEWEB)

    Moore, G.T.; Jacobson, S.R.; Hayashida, D.N. (Chevron Oil Field Research Co., La Habra, CA (United States))

    1991-03-01

    Sea-floor spreading assembled all the major cratonic blocks into a single supercontinent once in the Phanerozoic Eon. This unique Late Permian crustal tectonic event produced Pangaea and an enormous oceanic basin volume that dropped sea level to a global lowstand unrivaled in the Phanerozoic. Two paleoclimatic simulations using a numerical three-dimensional general circulation model tested changes in the greenhouse effect. The authors conclude that for a simulation to fit the Late Permian geologic record, the paleoatmosphere must contain an enhanced greenhouse gas effect. A third simulation tested changes of paleogeography in southern Pangaea (Gondwana) that did not appreciably alter the harsh continental paleoclimate. The simulated paleoclimatic changes provide extraordinarily warm ocean and atmosphere, and a significant reduction in continental rainfall and runoff. These conditions inevitably lead to more aridity and less vegetation on land, gradually reduce the delivery of vital nutrients from continental sources to marine margins, systematically liberate CO{sub 2} dissolved in ocean water, and incrementally increase stress on marine and terrestrial biotas. These consequences severely disrupted rates of oxygen and carbon cycling. Their quantitative paleoclimatic simulation is consistent with distributions of red beds, evaporites, coals, marine shelf areas, seawater isotope trends, and paleontologic originations and extinctions. Thus, the Pangaean plate assembly probably triggered an inexorable sequence of geophysical, geochemical, and biological events that forced an elevated greenhouse effect in the Late Permian, nearly annihilating the Phanerozoic biota.

  7. he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study

    Energy Technology Data Exchange (ETDEWEB)

    Keene, William C. [University of Virginia; Long, Michael S. [University of Virginia

    2013-05-20

    This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry's MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences

  8. Whale Multi-Disciplinary Studies: A Marine Education Infusion Unit. Northern New England Marine Education Project.

    Science.gov (United States)

    Maine Univ., Orono. Coll. of Education.

    This multidisciplinary unit deals with whales, whaling lore and history, and the interaction of the whale with the complex marine ecosystem. It seeks to teach adaptation of marine organisms. It portrays the concept that man is part of the marine ecosystem and man's activities can deplete and degrade marine ecosystems, endangering the survival of…

  9. Applying Movement Ecology to Marine Animals with Complex Life Cycles

    Science.gov (United States)

    Allen, Richard M.; Metaxas, Anna; Snelgrove, Paul V. R.

    2018-01-01

    Marine animals with complex life cycles may move passively or actively for fertilization, dispersal, predator avoidance, resource acquisition, and migration, and over scales from micrometers to thousands of kilometers. This diversity has catalyzed idiosyncratic and unfocused research, creating unsound paradigms regarding the role of movement in ecology and evolution. The emerging movement ecology paradigm offers a framework to consolidate movement research independent of taxon, life-history stage, scale, or discipline. This review applies the framework to movement among life-history stages in marine animals with complex life cycles to consolidate marine movement research and offer insights for scientists working in aquatic and terrestrial realms. Irrespective of data collection or simulation strategy, breaking each life-history stage down into the fundamental units of movement allows each unit to be studied independently or interactively with other units. Understanding these underlying mechanisms of movement within each life-history stage can then be used to construct lifetime movement paths. These paths can allow further investigation of the relative contributions and interdependencies of steps and phases across a lifetime and how these paths influence larger research topics, such as population-level movements.

  10. Phenomenological marine snow model for optical underwater image simulation: Applications to color restoration

    OpenAIRE

    Boffety , Matthieu; Galland , Frédéric

    2012-01-01

    International audience; Optical imaging plays an important role in oceanic science and engineering. However, the design of optical systems and image processing techniques for subsea environment are challenging tasks due to water turbidity. Marine snow is notably a major source of image degradation as it creates white bright spots that may strongly impact the performance of image processing methods. In this context, it is necessary to have a tool to foresee the behavior of these methods in mar...

  11. Supermarket Marine Biology.

    Science.gov (United States)

    Colby, Jennifer A.; And Others

    1995-01-01

    Describes a survey used to determine the availability of intact marine vertebrates and live invertebrates in supermarkets. Results shows that local supermarkets frequently provide a variety of intact marine organisms suitable for demonstrations, experiments, or dissections. (ZWH)

  12. 76 FR 77782 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-12-14

    ..., 1963), but because of ecological or physiological requirements, many marine animals may need to remain... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Commonwealth of the Northern Mariana Islands, February to March 2012 AGENCY: National Marine Fisheries Service (NMFS), National...

  13. 78 FR 17359 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2013-03-21

    ..., 1963), but because of ecological or physiological requirements, many marine animals may need to remain... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Northeast Atlantic Ocean, June to July, 2013 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...

  14. 76 FR 33246 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-06-08

    ... ecological or physiological requirements, many marine animals may need to remain in areas where they are... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Central-Western Bering Sea, August 2011 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...

  15. 75 FR 8652 - Incidental Takes of Marine Mammals During Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2010-02-25

    ... for marine animals before and during airgun operations. NMFS believes that the realistic possibility... Takes of Marine Mammals During Specified Activities; Marine Geophysical Survey in the Commonwealth of the Northern Mariana Islands, April to June 2010 AGENCY: National Marine Fisheries Service (NMFS...

  16. 77 FR 19242 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Science.gov (United States)

    2012-03-30

    ...., 1995; Thorpe, 1963), but because of ecological or physiological requirements, many marine animals may... Marine Mammals Incidental to Specified Activities; Low- Energy Marine Geophysical Survey in the Central Pacific Ocean, May Through June, 2012 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic...

  17. 77 FR 25966 - Takes of Marine Mammals Incidental to Specified Activities; Three Marine Geophysical Surveys in...

    Science.gov (United States)

    2012-05-02

    ..., 1963), but because of ecological or physiological requirements, many marine animals may need to remain... Marine Mammals Incidental to Specified Activities; Three Marine Geophysical Surveys in the Northeast Pacific Ocean, June Through July 2012 AGENCY: National Marine Fisheries Service, National Oceanic and...

  18. The multi-objective optimization of the horizontal-axis marine current turbine based on NSGA-II algorithm

    International Nuclear Information System (INIS)

    Zhu, G J; Guo, P C; Luo, X Q; Feng, J J

    2012-01-01

    The present paper describes a hydrodynamic optimization technique for horizontal-axial marine current turbine. The pitch angle distribution is important to marine current turbine. In this paper, the pitch angle distribution curve is parameterized as four control points by Bezier curve method. The coordinates of the four control points are chosen as optimization variables, and the sample space are structured according to the Box-Behnken experimental design method (BBD). Then the power capture coefficient and axial thrust coefficient in design tip-speed ratio is obtained for all the elements in the sample space by CFD numerical simulation. The power capture coefficient and axial thrust are chosen as objective function, and quadratic polynomial regression equations are constructed to fit the relationship between the optimization variables and each objective function according to response surface model. With the obtained quadratic polynomial regression equations as performance prediction model, the marine current turbine is optimized using the NSGA-II multi-objective genetic algorithm, which finally offers an improved marine current turbine.

  19. Emerging biopharmaceuticals from marine actinobacteria.

    Science.gov (United States)

    Hassan, Syed Shams Ul; Anjum, Komal; Abbas, Syed Qamar; Akhter, Najeeb; Shagufta, Bibi Ibtesam; Shah, Sayed Asmat Ali; Tasneem, Umber

    2017-01-01

    Actinobacteria are quotidian microorganisms in the marine world, playing a crucial ecological role in the recycling of refractory biomaterials and producing novel secondary metabolites with pharmaceutical applications. Actinobacteria have been isolated from the huge area of marine organisms including sponges, tunicates, corals, mollusks, crabs, mangroves and seaweeds. Natural products investigation of the marine actinobacteria revealed that they can synthesize numerous natural products including alkaloids, polyketides, peptides, isoprenoids, phenazines, sterols, and others. These natural products have a potential to provide future drugs against crucial diseases like cancer, HIV, microbial and protozoal infections and severe inflammations. Therefore, marine actinobacteria portray as a pivotal resource for marine drugs. It is an upcoming field of research to probe a novel and pharmaceutically important secondary metabolites from marine actinobacteria. In this review, we attempt to summarize the present knowledge on the diversity, chemistry and mechanism of action of marine actinobacteria-derived secondary metabolites from 2007 to 2016. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Marine oxygen holes as a consequence of oceanic acidification

    Science.gov (United States)

    Hofmann, M.; Schellnhuber, H.-J.

    2009-04-01

    An increase of atmospheric CO2 levels will not only drive future global mean temperatures towards values unprecedented during the whole Quaternary, but will also lead to an acidification of sea water which could harm the marine biota. Here we assess possible impacts of elevated atmospheric CO2 concentrations on the marine biological carbon pump by utilizing a business-as-usual emission scenario of anthropogenic CO2. A corresponding release of 4075 Petagrams of Carbon in total has been applied to simulate the current millennium by employing an Earth System Model of Intermediate Complexity (EMIC). This work is focused on studying the implications of reduced biogenic calcification caused by an increasing degree of oceanic acidification on the marine biological carbon pump. The attenuation of biogenic calcification imposes a small negative feedback on rising atmospheric pCO2 levels, tending to stabilize the Earth's climate. Since mineral ballast, notably particulate CaCO3, plays a dominant role in carrying organic matter through the water column, a reduction of its export fluxes weakens the strength of the biological carbon pump. There is, however, a dramatic effect discovered in our model world with severe consequences: since organic matter is oxidized in shallow waters when mineral-ballast fluxes weaken, oxygen holes (hypoxic zones) start to expand considerably in the oceans with potentially harmful impacts on a variety of marine ecosystems. Our study indicates that unbridled ocean acidification would exacerbate the observed hypoxia trends due to various environmental factors as reported in recent empirical studies.

  1. Marine Mineral Exploration

    DEFF Research Database (Denmark)

    in EEZ areas are fairly unknown; many areas need detailed mapping and mineral exploration, and the majority of coastal or island states with large EEZ areas have little experience in exploration for marine hard minerals. This book describes the systematic steps in marine mineral exploration....... Such exploration requires knowledge of mineral deposits and models of their formation, of geophysical and geochemical exploration methods, and of data evaluation and interpretation methods. These topics are described in detail by an international group of authors. A short description is also given of marine...

  2. 76 FR 68720 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Science.gov (United States)

    2011-11-07

    ... Marine Mammals Incidental to Specified Activities; Low- Energy Marine Geophysical Survey in the Western... conducting a low-energy marine geophysical (i.e., seismic) survey in the western tropical Pacific Ocean... Science Foundation (NSF), and ``Environmental Assessment of a Low-Energy Marine Geophysical Survey by the...

  3. 76 FR 18167 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-04-01

    ..., many marine animals may need to remain in areas where they are exposed to chronic stimuli (Richardson... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Central Gulf of Alaska, June, 2011 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric...

  4. 76 FR 6430 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-02-04

    ..., many marine animals may need to remain in areas where they are exposed to chronic stimuli (Richardson... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Pacific Ocean off Costa Rica, April Through May, 2011 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic...

  5. 76 FR 57959 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-09-19

    ..., many marine animals may need to remain in areas where they are exposed to chronic stimuli (Richardson... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Central Pacific Ocean, November, 2011 Through January, 2012 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...

  6. 78 FR 33357 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Science.gov (United States)

    2013-06-04

    ... confidence in these values is unknown. Table 3--Marine Mammal Density Estimates Density Species (animals/km\\2... unintentional taking of marine animals occurring incidental to the shock testing which involved large explosives... Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Conducting...

  7. 76 FR 7548 - Taking and Importing Marine Mammals; Taking of Marine Mammals Incidental to Conducting Precision...

    Science.gov (United States)

    2011-02-10

    ... Importing Marine Mammals; Taking of Marine Mammals Incidental to Conducting Precision Strike Weapons Testing and Training by Eglin Air Force Base in the Gulf of Mexico AGENCY: National Marine Fisheries Service... a Letter of Authorization. SUMMARY: In accordance with provisions of the Marine Mammal Protection...

  8. 75 FR 16754 - Taking and Importing Marine Mammals; Taking of Marine Mammals Incidental to Conducting Precision...

    Science.gov (United States)

    2010-04-02

    ... Importing Marine Mammals; Taking of Marine Mammals Incidental to Conducting Precision Strike Weapons Testing and Training by Eglin Air Force Base in the Gulf of Mexico AGENCY: National Marine Fisheries Service... a Letter of Authorization. SUMMARY: In accordance with provisions of the Marine Mammal Protection...

  9. Evaluation of Marine Corps Manpower Computer Simulation Model

    Science.gov (United States)

    2016-12-01

    Sanchez & Wan (2012). ............... 18  Figure 9.  MSM Program Flowchart . Adapted from Garrick (2014). ............... 20  Figure 10.  MOS-Grade State...Figure 9. MSM Program Flowchart . Adapted from Garrick (2014). The MSM is a time-step simulation where the metric for advancement is a one-year...19  A.  DEVELOPMENT APPROACH ...................................................... 19  B.  PROGRAM

  10. 77 FR 4765 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2012-01-31

    ... physiological requirements, many marine animals may need to remain in areas where they are exposed to chronic... readily audible to the animals based on measured received levels and the hearing sensitivity of the marine... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Northwest Pacific...

  11. Science-Based Approach for Advancing Marine and Hydrokinetic Energy: Integrating Numerical Simulations with Experiments

    Science.gov (United States)

    Sotiropoulos, F.; Kang, S.; Chamorro, L. P.; Hill, C.

    2011-12-01

    The field of MHK energy is still in its infancy lagging approximately a decade or more behind the technology and development progress made in wind energy engineering. Marine environments are characterized by complex topography and three-dimensional (3D) turbulent flows, which can greatly affect the performance and structural integrity of MHK devices and impact the Levelized Cost of Energy (LCoE). Since the deployment of multi-turbine arrays is envisioned for field applications, turbine-to-turbine interactions and turbine-bathymetry interactions need to be understood and properly modeled so that MHK arrays can be optimized on a site specific basis. Furthermore, turbulence induced by MHK turbines alters and interacts with the nearby ecosystem and could potentially impact aquatic habitats. Increased turbulence in the wake of MHK devices can also change the shear stress imposed on the bed ultimately affecting the sediment transport and suspension processes in the wake of these structures. Such effects, however, remain today largely unexplored. In this work a science-based approach integrating state-of-the-art experimentation with high-resolution computational fluid dynamics is proposed as a powerful strategy for optimizing the performance of MHK devices and assessing environmental impacts. A novel numerical framework is developed for carrying out Large-Eddy Simulation (LES) in arbitrarily complex domains with embedded MHK devices. The model is able to resolve the geometrical complexity of real-life MHK devices using the Curvilinear Immersed Boundary (CURVIB) method along with a wall model for handling the flow near solid surfaces. Calculations are carried out for an axial flow hydrokinetic turbine mounted on the bed of rectangular open channel on a grid with nearly 200 million grid nodes. The approach flow corresponds to fully developed turbulent open channel flow and is obtained from a separate LES calculation. The specific case corresponds to that studied

  12. Marine medicinal glycomics

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Pomin

    2014-01-01

    Full Text Available Glycomics is an international initiative aimed to understand the structure and function of the glycans from a given type of cell, tissue, organism, kingdom or even environment, as found under certain conditions. Glycomics is one of the latest areas of intense biological research. Glycans of marine sources are unique in terms of structure and function. They differ considerably from those of terrestrial origin. This review discusses the most known marine glycans of potential therapeutic properties. They are chitin, chitosan, and sulfated polysaccharides named glycosaminoglycans, sulfated fucans and sulfated galactans. Their medical actions are very broad. When certain structural requirements are found, these glycans can exhibit beneficial effects in inflammation, coagulation, thrombosis, cancer growth/metastasis and vascular biology. Both structure and therapeutic mechanisms of action of these marine glycans are discussed here in straight context with the current glycomic age through a project suggestively named Marine Medicinal Glycomics.

  13. 75 FR 19670 - Marine Highway Projects

    Science.gov (United States)

    2010-04-15

    ... DEPARTMENT OF TRANSPORTATION Maritime Administration Marine Highway Projects ACTION: Solicitation of applications for Marine highway projects. SUMMARY: The Department of Transportation is soliciting applications for Marine Highway Projects as specified in the America's Marine Highway Program Final Rule, MARAD...

  14. Sediment and contaminant transport in a marine environment

    International Nuclear Information System (INIS)

    Onishi, Y.; Thompson, F.L.

    1986-01-01

    The finite-element model FETRA is an unsteady, verically averaged two-dimensional model to simulate the transport of sediment and contaminants (radionuclides, heavy metals, pesticides, etc.) in coastal and estuarine water. The model, together with the hydrodynamic model CAFE-I, was applied to the Irish Sea to predict the migration and accumulation of sediment (both cohesive and noncohesive) and of a radionuclide (dissolved and sediment-sorbed) in a tide- and wind-driven system. The study demonstrated that FETRA is a useful tool for assessing sediment and toxic contaminant transport in a marine environment

  15. Command Filtered Adaptive Fuzzy Neural Network Backstepping Control for Marine Power System

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2014-01-01

    Full Text Available In order to retrain chaotic oscillation of marine power system which is excited by periodic electromagnetism perturbation, a novel command-filtered adaptive fuzzy neural network backstepping control method is designed. First, the mathematical model of marine power system is established based on the two parallel nonlinear model. Then, main results of command-filtered adaptive fuzzy neural network backstepping control law are given. And the Lyapunov stability theory is applied to prove that the system can remain closed-loop asymptotically stable with this controller. Finally, simulation results indicate that the designed controller can suppress chaotic oscillation with fast convergence speed that makes the system return to the equilibrium point quickly; meanwhile, the parameter which induces chaotic oscillation can also be discriminated.

  16. HNS-MS : Improving Member States preparedness to face an HNS pollution of the Marine System

    Science.gov (United States)

    Legrand, Sébastien; Le Floch, Stéphane; Aprin, Laurent; Partenay, Valérie; Donnay, Eric; Parmentier, Koen; Ovidio, Fabrice; Schallier, Ronny; Poncet, Florence; Chataing, Sophie; Poupon, Emmanuelle; Hellouvry, Yann-Hervé

    2017-04-01

    When dealing with a HNS pollution incident, one of the priority requirements is the identification of the hazard and an assessment of the risk posed to the public and responder safety, the environment and socioeconomic assets upon which a state or coastal community depend. The primary factors which determine the safety, environmental and socioeconomic impact of the released substance(s) relate to their physico-chemical properties and fate in the environment. Until now, preparedness actions at various levels have primarily aimed at classifying the general environmental or public health hazard of an HNS, or at performing a risk analysis of HNS transported in European marine regions. Operational datasheets have been (MIDSIS-TROCS) or are being (MAR-CIS) developed collating detailed, substance-specific information for responders and covering information needs at the first stage of an incident. However, contrary to oil pollution preparedness and response tools, only few decision-support tools used by Member State authorities (Coastguard agencies or other) integrate 3D models that are able to simulate the drift, fate and behaviour of HNS spills in the marine environment. When they do, they usually consider simplified or steady-state environmental conditions. As a significant step forward, a 'one-stop shop' integrated HNS decision-support system has been developed in the framework of the HNS-MS project. Focussing on the Bonn Agreement area, the system integrates 1. A database containing the physico-chemical parameters needed to compute the behaviour in the marine environment of 120 relevant HNS; 2. A digital atlas of the HNS environmental and socioeconomic vulnerability maps ; 3. A three dimensional HNS spill drift and fate model able to simulate HNS behaviour in the marine environment (including floaters, sinkers, evaporators and dissolvers). 4. A user-friendly web-based interface allowing Coastguard stations to launch a HNS drift simulation and visualize post

  17. 77 FR 841 - Taking and Importing Marine Mammals: Taking Marine Mammals Incidental to U.S. Navy Operations of...

    Science.gov (United States)

    2012-01-06

    ... and the Single Ping Equivalent (SPE) To model potential impacts to marine animals from exposure to... Atmospheric Administration 50 CFR Part 218 Taking and Importing Marine Mammals: Taking Marine Mammals... [Docket No. 110808485-1534-01] RIN 0648-BB14 Taking and Importing Marine Mammals: Taking Marine Mammals...

  18. Identifying Sources of Marine Litter

    OpenAIRE

    VEIGA Joana Mira; FLEET David; KINSEY Sue; NILSSON Per; VLACHOGIANNI Thomais; WERNER Stefanie; GALGANI Francois; THOMPSON Richard; DAGEVOS Jeroen; GAGO Jesus; SOBRAL Paula; CRONIN Richard

    2016-01-01

    Marine litter is a global problem causing harm to marine wildlife, coastal communities and maritime activities. It also embodies an emerging concern for human health and safety. The reduction of marine litter pollution poses a complex challenge for humankind, requiring adjustments in human behaviour as well as in the different phases of the life-cycle of products and across multiple economic sectors. The Marine Strategy Framework Directive (MSFD) requires European Member States to monitor...

  19. Chemical Investigations of Marine Filamentous and Zoosporic Fungi and Studies in Marine Microbial Chemical Ecology

    OpenAIRE

    Jenkins, Kelly M.

    1998-01-01

    The natural products chemistry of marine microorganisms is an emerging area of organic chemistry with the aim of discovering novel secondary metabolites exhibiting both biomedical and ecological activities. While marine bacteria have proven to be a productive source of new natural products, there are many groups of marine microorganisms which have not been fully investigated. In particular, marine fungi represent an untapped and potentially novel source of bioactive secondary metabolites. Whi...

  20. Research on export system of marine nuclear power device

    International Nuclear Information System (INIS)

    Fu Mingyu; Bian Xinqian; Shi Ji; Xin Chengdong; Wei Dong

    2002-01-01

    A marine nuclear power plant simulation system is founded, and a management expert system, which can administer and diagnose the typical faults, is constituted by the intelligent expert theory. This real-time expert system can analyze the reason of the typical fault caused by the nuclear power plant practically running and give the best solvent by the expert knowledge reasoning in the repository; a neural network fault inspection and diagnosis expert system which can inspect every equipment continually and give the faults diagnosis result based on the inspective dates is established. Based on the three hierarchical architecture, the operation performance is improved very much by using of the neural network fault inspection and diagnosis expert system to inspect and diagnose the nuclear power plant faults and the management expert system to supervise the nuclear power plant running. The expert system research can give guidance for the marine nuclear power plant safety operation

  1. Development of an engineering simulator for integral type PWR for nuclear ship

    International Nuclear Information System (INIS)

    Takahashi, Teruo; Shimazaki, Junya; Nakazawa, Toshio

    2000-01-01

    JAERI has developed a real-time engineering simulator for the integral type reactor MRX (Marine Reactor X) of power 100 MWt to evaluate the design and operational performance and to study highly automatic operations of a reactor plant. Marine reactor is operated under the conditions of pitching and rolling and load change, in comparison with a reactor for a land-based generating plant. And the MRX has systems with structural features, such as water-filled containment vessel, once-through type steam generator and emergency decay heat removal system. Considerations are paid to take these operational conditions and structural features into the simulation model. It is shown that the simulated results are consistent with the planned design and operational performance, and on the other hand present us some technical issues to be investigated in the design specifications. (author)

  2. Impact simulation of shrimp farm effluent on BOD-DO in Setiu River

    Science.gov (United States)

    Chong, Michael Sueng Lock; Teh, Su Yean; Koh, Hock Lye

    2017-08-01

    Release of effluent from intensive aquaculture farms into a river can pollute the receiving river and exert negative impacts on the aquatic ecosystem. In this paper, we simulate the effects of effluent released from a marine shrimp aquaculture farm into Sg Setiu, focusing on two critical water quality parameters i.e. DO (dissolved oxygen) and BOD (biochemical oxygen demand). DO is an important constituent in a river in sustaining water quality, with levels of DO below 5 mg/L deemed undesirable. DO levels can be depressed by the presence of BOD and other organics that consume DO. Water quality simulations in conjunction with management of effluent treatment can suggest mitigation measures for reducing the adverse environmental impact. For this purpose, an in-house two-dimensional water quality simulation model codenamed TUNA-WQ will be used for these simulations. TUNA-WQ has been undergoing regular updates and improvements to broaden the applicability and to improve the robustness. Here, the model is calibrated and verified for simulation of DO and BOD dynamics in Setiu River (Sg Setiu). TUNA-WQ simulated DO and BOD in Setiu River due to the discharge from a marine shrimp aquaculture farm will be presented.

  3. Oceanic processes in marine pollution

    International Nuclear Information System (INIS)

    Baumgartner, D.J.; Duedall, I.W.

    1990-01-01

    This book covers the following areas: bioaccumulation of Polycyclic Aromatic hydrocarbons in marine environments; behavior of drilling fluid discharges off the coast of California; effects of drilling fluids on marine organisms; and the effects of radioactive waste disposal on marine amphipods

  4. Influence of marine current on vertical migration of Pb in marine bay

    Science.gov (United States)

    Yu, Chen; Hong, Ai; Danfeng, Yang; Huijuan, Zhao; Dongfang, Yang

    2018-02-01

    This paper analyzed that vertical migration of Pb contents waters in Jiaozhou Bay, and revealed the influence of marine current on vertical migration process. Results showed that Pb contents in bottom waters of Jiaozhou Bay in April and July 1988 were 1.49-18.53 μg L-1 and 12.68/-27.64 μg L-1, respectively. The pollution level of Pb in bottom waters was moderate to heavy, and were showing temporal variations and spatial heterogeneity. The vertical migration process of Pb in April 1988 included a drifting process from the southwest to the north by means of the marine current was rapid in this region. The vertical migration process of Pb in July 1988 in the open waters included no drifting process since the flow rate of marine current was relative low in this region. The vertical migration process of Pb was jointly determined by vertical water’s effect, source input and water exchange, and the influence of marine current on the vertical migration of Pb in marine bay was significant.

  5. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  6. Advanced Geophysical Classification with the Marine Towed Array

    Science.gov (United States)

    Steinhurst, D.; Harbaugh, G.; Keiswetter, D.; Bell, T. W.; Massey, G.; Wright, D.

    2017-12-01

    The Marine Towed Array, or MTA, is an underwater dual-mode sensor array that has been successfully deployed at multiple marine venues in support of Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP) demonstrations beginning in 2004. It provided both marine electromagnetic and marine magnetic sensors for detection and mapping of underwater UXO. The EMI sensor array was based on older technology, which in several ESTCP demonstrations has not been able to support advanced geophysical classification (AGC). Under ESTCP funding, the U.S. Naval Research Laboratory is in the process of upgrading the MTA with modern, advanced electromagnetic (EMI) electronics and replacing the sensor array with a modern, multistatic array design. A half-scale version of the proposed array has been built and tested on land. Six tri-axial receiver cubes were placed inside two- and three- transmit coil configurations in equivalent positions to design locations for the MTA wing. The responses of a variety of munitions items and test spheres were measured over a range of target-to-array geometries and in both static and simulated dynamic data collection modes. The multi-transmit coil configuration was shown to provide enhanced single-pass classification performance over the original single coil design, particularly as a function of target location relative to the centerline. The ability to go beyond anomaly detection and additionally classify detected anomalies from survey data would dramatically improve the state of the art for underwater UXO remediation by reducing costs and improving the efficiency of these efforts. The results of our efforts to return the MTA to service and validating the new EMI array's design for UXO detection and classification in the underwater environment will be the focus of this presentation.

  7. 76 FR 12070 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2011-03-04

    ... Energy's EROS operations in 2010: Marine mammals Biological impacts Company Structure Dates sighted... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...

  8. 77 FR 45341 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2012-07-31

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...). SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations...

  9. 77 FR 16539 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2012-03-21

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...). SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations...

  10. 78 FR 22517 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2013-04-16

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...). SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations...

  11. 75 FR 31423 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2010-06-03

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...: In accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification...

  12. 78 FR 13865 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2013-03-01

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...). SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations...

  13. 77 FR 39485 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2012-07-03

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...). SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations...

  14. Marine Fish Hybridization

    KAUST Repository

    He, Song

    2017-04-01

    Natural hybridization is reproduction (without artificial influence) between two or more species/populations which are distinguishable from each other by heritable characters. Natural hybridizations among marine fishes were highly underappreciated due to limited research effort; it seems that this phenomenon occurs more often than is commonly recognized. As hybridization plays an important role in biodiversity processes in the marine environment, detecting hybridization events and investigating hybridization is important to understand and protect biodiversity. The first chapter sets the framework for this disseration study. The Cohesion Species Concept was selected as the working definition of a species for this study as it can handle marine fish hybridization events. The concept does not require restrictive species boundaries. A general history and background of natural hybridization in marine fishes is reviewed during in chapter as well. Four marine fish hybridization cases were examed and documented in Chapters 2 to 5. In each case study, at least one diagnostic nuclear marker, screened from among ~14 candidate markers, was found to discriminate the putative hybridizing parent species. To further investigate genetic evidence to support the hybrid status for each hybrid offspring in each case, haploweb analysis on diagnostic markers (nuclear and/or mitochondrial) and the DAPC/PCA analysis on microsatellite data were used. By combining the genetic evidences, morphological traits, and ecological observations together, the potential reasons that triggered each hybridization events and the potential genetic/ecology effects could be discussed. In the last chapter, sequences from 82 pairs of hybridizing parents species (for which COI barcoding sequences were available either on GenBank or in our lab) were collected. By comparing the COI fragment p-distance between each hybridizing parent species, some general questions about marine fish hybridization were discussed: Is

  15. Exploring the co-evolution of marine ecology and environment in silico

    Science.gov (United States)

    Ridgwell, A.

    2015-12-01

    Species do not live in isolation, but adapt and ultimately, evolve, in relationship with other species as well as with their chemical and physical environment. In the marine environment, this interaction is intimately two-way - the surface biogeochemical environment modulates the makeup of the pelagic ecosystem, yet at the same time, the ecosystem assemblage, by setting the strength of the biological pump and ultimately, in regulating the carbon and nutrient inventory of the ocean and atmospheric pCO2, influences the surface geochemical environment. Feedbacks, both negative and positive, must therefore exist between plankton ecology and global biogeochemical cycles. This has implications for understanding the geological record and particularly the response and recovery of marine ecosystems following major environmental perturbation, but also complicates making projections of future ocean changes. To address a coupled system such as this, new numerical tools are needed as traditional 'functional type' marine ecosystem models are generally incapable of accounting for short-term adaptation, let alone long-term evolution. What is needed is the combination of a plankton model able to simulate a highly diverse ecology plus 'genetic' mutation (changes in trait value(s)) and extinction, *and* an Earth system model capable of simulating long-term evolution of the climatology and geochemistry of the ocean. The Earth system model 'cGENIE' - http://mycgenie.seao2.org generally fills the second criteria, so for this presentation I will focus on the structure of the ecosystem model, the associated methodology, and numerical techniques for dealing with what will turn out to be an exceptionally large number of ocean tracers. If you are really lucky, there may even be some preliminary results :)

  16. Electromagnetic trajectory simulation using triaxial cage

    Science.gov (United States)

    Modi, Ankita; Kazi, Faruk

    2018-02-01

    This paper implements an open-loop controller for generating earth's magnetic field in vessel's co-ordinate frame. It also incorporates the rotational movements along the three axes, without physically moving the object. This has potential application in prediction of signature for ferromagnetic marine vessels in changing earth's magnetic field experienced by the vessel due to change in location. It also considers the effect of roll, pitch and heading changes. Uniform magnetic field simulator is designed to generate the required magnetic field in the vessel's coordinate frame. Simulation results are verified using experimental laboratory setup.

  17. 77 FR 50289 - Taking and Importing Marine Mammals: Taking Marine Mammals Incidental to U.S. Navy Operations of...

    Science.gov (United States)

    2012-08-20

    ... areas of high marine animal densities, we believe that the incidental take of marine mammals would... response, tagging of free-ranging marine animals at-sea, and radar-based detection of marine mammals from... effects of sonar use will not be greater on animals listed under the ESA than the effects on other marine...

  18. Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud

    Energy Technology Data Exchange (ETDEWEB)

    Klein, S A; McCoy, R B; Morrison, H; Ackerman, A; Avramov, A; deBoer, G; Chen, M; Cole, J; DelGenio, A; Golaz, J; Hashino, T; Harrington, J; Hoose, C; Khairoutdinov, M; Larson, V; Liu, X; Luo, Y; McFarquhar, G; Menon, S; Neggers, R; Park, S; Poellot, M; von Salzen, K; Schmidt, J; Sednev, I; Shipway, B; Shupe, M; Spangenberg, D; Sud, Y; Turner, D; Veron, D; Falk, M; Foster, M; Fridlind, A; Walker, G; Wang, Z; Wolf, A; Xie, S; Xu, K; Yang, F; Zhang, G

    2008-02-27

    Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a cold-air outbreak mixed-phase stratocumulus cloud observed during the Atmospheric Radiation Measurement (ARM) program's Mixed-Phase Arctic Cloud Experiment. The observed cloud occurred in a well-mixed boundary layer with a cloud top temperature of -15 C. The observed liquid water path of around 160 g m{sup -2} was about two-thirds of the adiabatic value and much greater than the mass of ice crystal precipitation which when integrated from the surface to cloud top was around 15 g m{sup -2}. The simulations were performed by seventeen single-column models (SCMs) and nine cloud-resolving models (CRMs). While the simulated ice water path is generally consistent with the observed values, the median SCM and CRM liquid water path is a factor of three smaller than observed. Results from a sensitivity study in which models removed ice microphysics indicate that in many models the interaction between liquid and ice-phase microphysics is responsible for the large model underestimate of liquid water path. Despite this general underestimate, the simulated liquid and ice water paths of several models are consistent with the observed values. Furthermore, there is some evidence that models with more sophisticated microphysics simulate liquid and ice water paths that are in better agreement with the observed values, although considerable scatter is also present. Although no single factor guarantees a good simulation, these results emphasize the need for improvement in the model representation of mixed-phase microphysics. This case study, which has been well observed from both aircraft and ground-based remote sensors, could be a benchmark for model simulations of mixed-phase clouds.

  19. The effect of moving waves on neutral marine atmospheric boundary layer

    Directory of Open Access Journals (Sweden)

    Sam Ali Al

    2014-01-01

    Full Text Available Large eddy simulations are performed to study the effects of wind-wave direction misalignment of the neutral marine atmospheric boundary layer over a wavy wall. The results show that the wind-wave misalignment has a significant effect on the velocity profiles and the pressure fluctuation over the wave surface. These effects are not confined to the near wave surface region but extend over the whole atmospheric surface layer.

  20. 75 FR 972 - Nomination of Existing Marine Protected Areas to the National System of Marine Protected Areas

    Science.gov (United States)

    2010-01-07

    ... Marine Protected Areas to the National System of Marine Protected Areas AGENCY: NOAA, Department of... Federal, State and territorial marine protected area programs to join the National System of Marine Protected Areas. SUMMARY: NOAA and the Department of the Interior (DOI) invited Federal, State, commonwealth...

  1. 76 FR 35856 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2011-06-20

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  2. 75 FR 8921 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2010-02-26

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  3. 76 FR 33704 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2011-06-09

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  4. 77 FR 10481 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2012-02-22

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  5. 76 FR 23570 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2011-04-27

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  6. 75 FR 28566 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2010-05-21

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  7. 75 FR 54851 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2010-09-09

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  8. 75 FR 38078 - Incidental Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal...

    Science.gov (United States)

    2010-07-01

    ... Taking of Marine Mammals; Taking of Marine Mammals Incidental to the Explosive Removal of Offshore Structures in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... accordance with the Marine Mammal Protection Act (MMPA) and implementing regulations, notification is hereby...

  9. Assumed Probability Density Functions for Shallow and Deep Convection

    OpenAIRE

    Steven K Krueger; Peter A Bogenschutz; Marat Khairoutdinov

    2010-01-01

    The assumed joint probability density function (PDF) between vertical velocity and conserved temperature and total water scalars has been suggested to be a relatively computationally inexpensive and unified subgrid-scale (SGS) parameterization for boundary layer clouds and turbulent moments. This paper analyzes the performance of five families of PDFs using large-eddy simulations of deep convection, shallow convection, and a transition from stratocumulus to trade wind cumulus. Three of the PD...

  10. Simulation and Analysis of Chain Drive Systems

    DEFF Research Database (Denmark)

    Pedersen, Sine Leergaard

    mathematical models, and compare to the prior done research. Even though the model is developed at first for the use of analysing chain drive systems in marine engines, the methods can with small changes be used in general, as for e.g. chain drives in industrial machines, car engines and motorbikes. A novel...... with a real tooth profile proves superior to other applied models. With this model it is possible to perform a dynamic simulation of large marine engine chain drives. Through the application of this method, it is shown that the interrelated dynamics of the elements in the chain drive system is captured...

  11. Enzymatic Processes in Marine Biotechnology.

    Science.gov (United States)

    Trincone, Antonio

    2017-03-25

    In previous review articles the attention of the biocatalytically oriented scientific community towards the marine environment as a source of biocatalysts focused on the habitat-related properties of marine enzymes. Updates have already appeared in the literature, including marine examples of oxidoreductases, hydrolases, transferases, isomerases, ligases, and lyases ready for food and pharmaceutical applications. Here a new approach for searching the literature and presenting a more refined analysis is adopted with respect to previous surveys, centering the attention on the enzymatic process rather than on a single novel activity. Fields of applications are easily individuated: (i) the biorefinery value-chain, where the provision of biomass is one of the most important aspects, with aquaculture as the prominent sector; (ii) the food industry, where the interest in the marine domain is similarly developed to deal with the enzymatic procedures adopted in food manipulation; (iii) the selective and easy extraction/modification of structurally complex marine molecules, where enzymatic treatments are a recognized tool to improve efficiency and selectivity; and (iv) marine biomarkers and derived applications (bioremediation) in pollution monitoring are also included in that these studies could be of high significance for the appreciation of marine bioprocesses.

  12. 75 FR 72655 - Marine Sanitation Device Discharge Regulations for the Florida Keys National Marine Sanctuary

    Science.gov (United States)

    2010-11-26

    ... National Marine Sanctuary AGENCY: Office of National Marine Sanctuaries (ONMS), National Oceanic and... the regulations for the Florida Keys National Marine Sanctuary (FKNMS or sanctuary) by eliminating the exemption that allows discharges from within the boundary of the sanctuary of biodegradable effluent...

  13. Effects of acidification on olfactory-mediated behaviour in freshwater and marine ecosystems: a synthesis.

    Science.gov (United States)

    Leduc, Antoine O H C; Munday, Philip L; Brown, Grant E; Ferrari, Maud C O

    2013-01-01

    For many aquatic organisms, olfactory-mediated behaviour is essential to the maintenance of numerous fitness-enhancing activities, including foraging, reproduction and predator avoidance. Studies in both freshwater and marine ecosystems have demonstrated significant impacts of anthropogenic acidification on olfactory abilities of fish and macroinvertebrates, leading to impaired behavioural responses, with potentially far-reaching consequences to population dynamics and community structure. Whereas the ecological impacts of impaired olfactory-mediated behaviour may be similar between freshwater and marine ecosystems, the underlying mechanisms are quite distinct. In acidified freshwater, molecular change to chemical cues along with reduced olfaction sensitivity appear to be the primary causes of olfactory-mediated behavioural impairment. By contrast, experiments simulating future ocean acidification suggest that interference of high CO2 with brain neurotransmitter function is the primary cause for olfactory-mediated behavioural impairment in fish. Different physico-chemical characteristics between marine and freshwater systems are probably responsible for these distinct mechanisms of impairment, which, under globally rising CO2 levels, may lead to strikingly different consequences to olfaction. While fluctuations in pH may occur in both freshwater and marine ecosystems, marine habitat will remain alkaline despite future ocean acidification caused by globally rising CO2 levels. In this synthesis, we argue that ecosystem-specific mechanisms affecting olfaction need to be considered for effective management and conservation practices.

  14. Prevalence of marine debris in marine birds from the North Atlantic.

    Science.gov (United States)

    Provencher, Jennifer F; Bond, Alexander L; Hedd, April; Montevecchi, William A; Muzaffar, Sabir Bin; Courchesne, Sarah J; Gilchrist, H Grant; Jamieson, Sarah E; Merkel, Flemming R; Falk, Knud; Durinck, Jan; Mallory, Mark L

    2014-07-15

    Marine birds have been found to ingest plastic debris in many of the world's oceans. Plastic accumulation data from necropsies findings and regurgitation studies are presented on 13 species of marine birds in the North Atlantic, from Georgia, USA to Nunavut, Canada and east to southwest Greenland and the Norwegian Sea. Of the species examined, the two surface plungers (great shearwaters Puffinus gravis; northern fulmars Fulmarus glacialis) had the highest prevalence of ingested plastic (71% and 51%, respectively). Great shearwaters also had the most pieces of plastics in their stomachs, with some individuals containing as many of 36 items. Seven species contained no evidence of plastic debris. Reporting of baseline data as done here is needed to ensure that data are available for marine birds over time and space scales in which we see changes in historical debris patterns in marine environments (i.e. decades) and among oceanographic regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Evolution of movement rate increases the effectiveness of marine reserves for the conservation of pelagic fishes.

    Science.gov (United States)

    Mee, Jonathan A; Otto, Sarah P; Pauly, Daniel

    2017-06-01

    Current debates about the efficacy of no-take marine reserves (MR) in protecting large pelagic fish such as tuna and sharks have usually not considered the evolutionary dimension of this issue, which emerges because the propensity to swim away from a given place, like any other biological trait, will probably vary in a heritable fashion among individuals. Here, based on spatially explicit simulations, we investigated whether selection to remain in MRs to avoid higher fishing mortality can lead to the evolution of more philopatric fish. Our simulations, which covered a range of life histories among tuna species (skipjack tuna vs. Atlantic bluefin tuna) and shark species (great white sharks vs. spiny dogfish), suggested that MRs were most effective at maintaining viable population sizes when movement distances were lowest. Decreased movement rate evolved following the establishment of marine reserves, and this evolution occurred more rapidly with higher fishing pressure. Evolutionary reductions in movement rate led to increases in within-reserve population sizes over the course of the 50 years following MR establishment, although this varied among life histories, with skipjack responding fastest and great white sharks slowest. Our results suggest the evolution of decreased movement can augment the efficacy of marine reserves, especially for species, such as skipjack tuna, with relatively short generation times. Even when movement rates did not evolve substantially over 50 years (e.g., given long generation times or little heritable variation), marine reserves were an effective tool for the conservation of fish populations when mean movement rates were low or MRs were large.

  16. Ship Observations and Numerical Simulation of the Marine Atmosphericboundary Layer over the Spring Oceanic Front in the Northwestern South China Sea

    Science.gov (United States)

    Wang, D.; Shi, R.; Chen, J.; Guo, X.; Zeng, L.; Li, J.; Xie, Q.; Wang, X.

    2017-12-01

    The response of the marine atmospheric boundary layer (MABL) structure to an oceanic front is analyzed using Global Positioning System (GPS) sounding data obtained during a survey in the northwestern South China Sea (NSCS) over a period of about one week in April 2013. The Weather Research and Forecasting (WRF) model is used to further examine the thermodynamical mechanisms of the MABL's response to the front. The WRF model successfully simulates the change in the MABL structure across the front, which agrees well with the observations. The spatially high-pass-filtered fields of sea surface temperature (SST) and 10-m neutral equivalent wind from the WRF model simulation show a tight, positive coupling between the SST and surface winds near the front. Meanwhile, the SST front works as a damping zone to reduce the enhancement of wind blowing from the warm to the cold side of the front in the lower boundary layer. Analysis of the momentum budget shows that the most active and significant term affecting horizontal momentum over the frontal zone is the adjustment of the pressure gradient. It is found that the front in the NSCS is wide enough for slowly moving air parcels to be affected by the change in underlying SST. The different thermal structure upwind and downwind of the front causes a baroclinic adjustment of the perturbation pressure from the surface to the mid-layer of the MABL, which dominates the change in the wind profile across the front.

  17. Fishing destabilizes the biomass flow in the marine size spectrum

    OpenAIRE

    Rochet, M.-J.; Benoît, E.

    2011-01-01

    Fishing impacts on marine food webs are predicted by simulations of a size spectrum community model. In this model, predation is determined by predator and prey size and abundance, and drives predator growth and prey mortality. Fishing amplifies temporal oscillations in the biomass flow. Oscillations appear at lower fishing intensity and have wider amplitude when fishing is selective (removes a narrow size range) and/or when large fish are targeted, than when fishing is more balanced (catchin...

  18. Coexistence dilemmas in European marine spatial planning practices. The case of marine renewables and marine protected areas

    International Nuclear Information System (INIS)

    Kyriazi, Zacharoula; Maes, Frank; Degraer, Steven

    2016-01-01

    The question whether coexistence of marine renewable energy (MRE) projects and marine protected areas (MPAs) is a common spatial policy in Europe and how a number of factors can affect it, has been addressed by empirical research undertaken in eleven European marine areas. Policy drivers and objectives that are assumed to affect coexistence, such as the fulfillment of conservation objectives and the prioritization of other competing marine uses, were scored by experts and predictions were crosschecked with state practice. While in most areas MRE-MPA coexistence is not prohibited by law, practice indicates resistance towards it. Furthermore expert judgment demonstrated that a number of additional factors, such as the lack of suitable space for MRE projects and the uncertainty about the extent of damage by MRE to the MPA, might influence the intentions of the two major parties involved (i.e. the MRE developer and the MPA authority) to pursue or avoid coexistence. Based on these findings, the interactions of these two players are further interpreted, their policy implications are discussed, while the need towards efficient, fair and acceptable MRE-MPA coexistence is highlighted.

  19. Bioprospecting Marine Plankton

    Directory of Open Access Journals (Sweden)

    Chris Bowler

    2013-11-01

    Full Text Available The ocean dominates the surface of our planet and plays a major role in regulating the biosphere. For example, the microscopic photosynthetic organisms living within provide 50% of the oxygen we breathe, and much of our food and mineral resources are extracted from the ocean. In a time of ecological crisis and major changes in our society, it is essential to turn our attention towards the sea to find additional solutions for a sustainable future. Remarkably, while we are overexploiting many marine resources, particularly the fisheries, the planktonic compartment composed of zooplankton, phytoplankton, bacteria and viruses, represents 95% of marine biomass and yet the extent of its diversity remains largely unknown and underexploited. Consequently, the potential of plankton as a bioresource for humanity is largely untapped. Due to their diverse evolutionary backgrounds, planktonic organisms offer immense opportunities: new resources for medicine, cosmetics and food, renewable energy, and long-term solutions to mitigate climate change. Research programs aiming to exploit culture collections of marine micro-organisms as well as to prospect the huge resources of marine planktonic biodiversity in the oceans are now underway, and several bioactive extracts and purified compounds have already been identified. This review will survey and assess the current state-of-the-art and will propose methodologies to better exploit the potential of marine plankton for drug discovery and for dermocosmetics.

  20. Freshwater savings from marine protein consumption

    International Nuclear Information System (INIS)

    Gephart, Jessica A; Pace, Michael L; D’Odorico, Paolo

    2014-01-01

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km 3  yr −1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km 3  yr −1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture. (paper)

  1. Improved Point Analysis Model (IPAM) (Users Guide)

    Science.gov (United States)

    1991-02-01

    Descriptions 7 Stratus fractus of bad weather* or Cumulus fractus of bad weather, or both ( pannus ), usually below Altostratus or Nimbostratus. 8...Cumulonimbus without anvil or fibrous upper part, Cumulus, Stratocumulus, Stratus or pannus . / Stratocumulus, Stratus, Cumulus and Cumulonimbus invisible owing

  2. Grounding line transient response in marine ice sheet models

    Directory of Open Access Journals (Sweden)

    A. S. Drouet

    2013-03-01

    Full Text Available Marine ice-sheet stability is mostly controlled by the dynamics of the grounding line, i.e. the junction between the grounded ice sheet and the floating ice shelf. Grounding line migration has been investigated within the framework of MISMIP (Marine Ice Sheet Model Intercomparison Project, which mainly aimed at investigating steady state solutions. Here we focus on transient behaviour, executing short-term simulations (200 yr of a steady ice sheet perturbed by the release of the buttressing restraint exerted by the ice shelf on the grounded ice upstream. The transient grounding line behaviour of four different flowline ice-sheet models has been compared. The models differ in the physics implemented (full Stokes and shallow shelf approximation, the numerical approach, as well as the grounding line treatment. Their overall response to the loss of buttressing is found to be broadly consistent in terms of grounding line position, rate of surface elevation change and surface velocity. However, still small differences appear for these latter variables, and they can lead to large discrepancies (> 100% observed in terms of ice sheet contribution to sea level when cumulated over time. Despite the recent important improvements of marine ice-sheet models in their ability to compute steady state configurations, our results question the capacity of these models to compute short-term reliable sea-level rise projections.

  3. Docking Simulation of the Binding Interactions of Saxitoxin Analogs Produced by the Marine Dinoflagellate Gymnodinium catenatum to the Voltage-Gated Sodium Channel Nav1.4

    Directory of Open Access Journals (Sweden)

    Lorena M. Durán-Riveroll

    2016-05-01

    Full Text Available Saxitoxin (STX and its analogs are paralytic alkaloid neurotoxins that block the voltage-gated sodium channel pore (Nav, impeding passage of Na+ ions into the intracellular space, and thereby preventing the action potential in the peripheral nervous system and skeletal muscle. The marine dinoflagellate Gymnodinium catenatum produces an array of such toxins, including the recently discovered benzoyl analogs, for which the mammalian toxicities are essentially unknown. We subjected STX and its analogs to a theoretical docking simulation based upon two alternative tri-dimensional models of the Nav1.4 to find a relationship between the binding properties and the known mammalian toxicity of selected STX analogs. We inferred hypothetical toxicities for the benzoyl analogs from the modeled values. We demonstrate that these toxins exhibit different binding modes with similar free binding energies and that these alternative binding modes are equally probable. We propose that the principal binding that governs ligand recognition is mediated by electrostatic interactions. Our simulation constitutes the first in silico modeling study on benzoyl-type paralytic toxins and provides an approach towards a better understanding of the mode of action of STX and its analogs.

  4. Docking Simulation of the Binding Interactions of Saxitoxin Analogs Produced by the Marine Dinoflagellate Gymnodinium catenatum to the Voltage-Gated Sodium Channel Nav1.4.

    Science.gov (United States)

    Durán-Riveroll, Lorena M; Cembella, Allan D; Band-Schmidt, Christine J; Bustillos-Guzmán, José J; Correa-Basurto, José

    2016-05-06

    Saxitoxin (STX) and its analogs are paralytic alkaloid neurotoxins that block the voltage-gated sodium channel pore (Nav), impeding passage of Na⁺ ions into the intracellular space, and thereby preventing the action potential in the peripheral nervous system and skeletal muscle. The marine dinoflagellate Gymnodinium catenatum produces an array of such toxins, including the recently discovered benzoyl analogs, for which the mammalian toxicities are essentially unknown. We subjected STX and its analogs to a theoretical docking simulation based upon two alternative tri-dimensional models of the Nav1.4 to find a relationship between the binding properties and the known mammalian toxicity of selected STX analogs. We inferred hypothetical toxicities for the benzoyl analogs from the modeled values. We demonstrate that these toxins exhibit different binding modes with similar free binding energies and that these alternative binding modes are equally probable. We propose that the principal binding that governs ligand recognition is mediated by electrostatic interactions. Our simulation constitutes the first in silico modeling study on benzoyl-type paralytic toxins and provides an approach towards a better understanding of the mode of action of STX and its analogs.

  5. Databases of the marine metagenomics

    KAUST Repository

    Mineta, Katsuhiko

    2015-10-28

    The metagenomic data obtained from marine environments is significantly useful for understanding marine microbial communities. In comparison with the conventional amplicon-based approach of metagenomics, the recent shotgun sequencing-based approach has become a powerful tool that provides an efficient way of grasping a diversity of the entire microbial community at a sampling point in the sea. However, this approach accelerates accumulation of the metagenome data as well as increase of data complexity. Moreover, when metagenomic approach is used for monitoring a time change of marine environments at multiple locations of the seawater, accumulation of metagenomics data will become tremendous with an enormous speed. Because this kind of situation has started becoming of reality at many marine research institutions and stations all over the world, it looks obvious that the data management and analysis will be confronted by the so-called Big Data issues such as how the database can be constructed in an efficient way and how useful knowledge should be extracted from a vast amount of the data. In this review, we summarize the outline of all the major databases of marine metagenome that are currently publically available, noting that database exclusively on marine metagenome is none but the number of metagenome databases including marine metagenome data are six, unexpectedly still small. We also extend our explanation to the databases, as reference database we call, that will be useful for constructing a marine metagenome database as well as complementing important information with the database. Then, we would point out a number of challenges to be conquered in constructing the marine metagenome database.

  6. Study on seasonal IR signature change of a ship by considering seasonal marine environmental conditions

    Science.gov (United States)

    Kim, Do-Hwi; Han, Kuk-Il; Choi, Jun-Hyuk; Kim, Tae-Kuk

    2017-05-01

    Infrared (IR) signal emitted from objects over 0 degree Kelvin has been used to detect and recognize the characteristics of those objects. Recently more delicate IR sensors have been applied for various guided missiles and they affect a crucial influence on object's survivability. Especially, in marine environment it is more vulnerable to be attacked by IR guided missiles since there are nearly no objects for concealment. To increase the survivability of object, the IR signal of the object needs to be analyzed properly by considering various marine environments. IR signature of a naval ship consists of the emitted energy from ship surface and the reflected energy by external sources. Surface property such as the emissivity and the absorptivity on the naval ship varies with different paints applied on the surface and the reflected IR signal is also affected by the surface radiative property, the sensor's geometric position and various climatic conditions in marine environment. Since the direct measurement of IR signal using IR camera is costly and time consuming job, computer simulation methods are developing rapidly to replace those experimental tasks. In this study, we are demonstrate a way of analyzing the IR signal characteristics by using the measured background IR signals using an IR camera and the estimated target IR signals from the computer simulation to find the seasonal trends of IR threats of a naval ship. Through this process, measured weather data are used to analyze more accurate IR signal conditions for the naval ship. The seasonal change of IR signal contrast between the naval ship and the marine background shows that the highest contrast radiant intensity (CRI) value is appeared in early summer.

  7. 50 CFR 14.18 - Marine mammals.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Marine mammals. 14.18 Section 14.18....18 Marine mammals. Any person subject to the jurisdiction of the United States who has lawfully taken a marine mammal on the high seas and who is authorized to import such marine mammal in accordance...

  8. 76 FR 11205 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Construction and...

    Science.gov (United States)

    2011-03-01

    ... Importing Marine Mammals; Taking Marine Mammals Incidental to Construction and Operation of a Liquefied Natural Gas Deepwater Port in the Gulf of Mexico AGENCY: National Marine Fisheries Service (NMFS... request from Port Dolphin Energy LLC (Port Dolphin) for authorization for the take, by Level B harassment...

  9. The Development of Coastal and Marine

    Directory of Open Access Journals (Sweden)

    Suharto Widjojo

    2004-01-01

    Full Text Available Planning and development process of oastaland marine resources tends centralized and adopted top down policy, without any active participations from coastal and marine communities. In order to reach integrated and sustainable development in coastaland marine areas, people should have both complete and up to date information, so that planning and decision making for all aspect of the environment can be done easily. People should give a high attention of surveis, mappings, as well as science and technology of coastal and marine sectors, in order to change the paradigm of development from inland to coastal and marine. Moreover, people should give high attention of potential resources of coastal and marine areas.

  10. Modelling the impact of discharges of technologically enhanced natural series radionuclides in the marine environment

    International Nuclear Information System (INIS)

    Scott, E.M.; Baxter, M.S.

    1997-01-01

    Natural radionuclides are used within the marine environment to study particle associated processes such as scavenging and sedimentary re-working (Th-234) and to date events and measure rates (Pb-210). In addition, Po-210 has been shown to make a significant contribution to the collective dose of the world population through consumption of marine products (fish). The interpretation of observed activity ratios in the environment is presented, based on earlier description. The natural marine system may however undergo a number of disturbances on a local scale due to discharges of technologically enhanced radionuclides from industrial processes such as phosphate ore processing and scaling in oil and gas production. Some work done to extend the original Bateman equations is shown to describe the behaviour of a decay series under a number of different types of perturbations, and the approach is demonstrated through simulation of a simple system. (author)

  11. Calanoid Copepod Behavior in Thin Layer Shear Flows: Freshwater Versus Marine

    Science.gov (United States)

    Skipper, A. N.; Webster, D. R.; Yen, J.

    2015-11-01

    Marine copepods have been shown to behaviorally respond to vertical gradients of horizontal velocity and aggregate around thin layers. The current study addresses whether a freshwater copepod from an alpine lake demonstrates similar behavior response. Hesperodiaptomus shoshone is often the greatest biomass in alpine lakes and is the dominant zooplankton predator within its environment. The hypothesis is that H. shoshone responds to vertical gradients of horizontal velocity, which are associated with river outflows from alpine lakes, with fine-scale changes in swimming kinematics. The two calanoid copepods studied here, H. shoshone (freshwater) and Calanus finmarchicus(marine), are of similar size (2 - 4 mm), have similar morphologies, and utilize cruising as their primary swimming mode. The two animals differ not only in environment, but also in diet; H. shoshone is a carnivore, whereas C. finmarchicusis an herbivore. A laminar, planar jet (Bickley) was used in the laboratory to simulate a free shear flow. Particle image velocimetry (PIV) quantified the flow field. The marine species changed its swimming behavior significantly (increased swimming speed and turning frequency) and spent more time in the layer (40% vs. 70%) from control to treatment. In contrast, the freshwater species exhibited very few changes in either swimming behavior or residence time. Swimming kinematics and residence time results were also similar between males and females. Unlike the marine copepod, the results suggest the environmental flow structure is unimportant to the freshwater species.

  12. Global marine radioactivity database (GLOMARD)

    International Nuclear Information System (INIS)

    Povinec, P.P.; Gayol, J.; Togawa, O.

    1999-01-01

    In response to the request of Member States and under the IAEA's mandate, the IAEA Marine Environment Laboratory (MEL) in Monaco has established and maintains a Global Marine Radioactivity Database (GLOMARD). It is a vast project compiling radionuclide measurements taken in the marine environment. It consists of systematic input of all radionuclide concentration data available for sea water, sediment, biota and suspended matter. The GLOMARD is therefore a powerful tool for the researchers of MEL as it integrates the results of analyses in most of the areas of the marine environment which have been investigated

  13. Improved Marine Waters Monitoring

    Science.gov (United States)

    Palazov, Atanas; Yakushev, Evgeniy; Milkova, Tanya; Slabakova, Violeta; Hristova, Ognyana

    2017-04-01

    IMAMO - Improved Marine Waters Monitoring is a project under the Programme BG02: Improved monitoring of marine waters, managed by Bulgarian Ministry of environment and waters and co-financed by the Financial Mechanism of the European Economic Area (EEA FM) 2009 - 2014. Project Beneficiary is the Institute of oceanology - Bulgarian Academy of Sciences with two partners: Norwegian Institute for Water Research and Bulgarian Black Sea Basin Directorate. The Project aims to improve the monitoring capacity and expertise of the organizations responsible for marine waters monitoring in Bulgaria to meet the requirements of EU and national legislation. The main outcomes are to fill the gaps in information from the Initial assessment of the marine environment and to collect data to assess the current ecological status of marine waters including information as a base for revision of ecological targets established by the monitoring programme prepared in 2014 under Art. 11 of MSFD. Project activities are targeted to ensure data for Descriptors 5, 8 and 9. IMAMO aims to increase the institutional capacity of the Bulgarian partners related to the monitoring and assessment of the Black Sea environment. The main outputs are: establishment of real time monitoring and set up of accredited laboratory facilities for marine waters and sediments chemical analysis to ensure the ability of Bulgarian partners to monitor progress of subsequent measures undertaken.

  14. Modeling the impact of watershed management policies on marine ecosystem services with application to Hood Canal, WA, USA

    Science.gov (United States)

    Sutherland, D. A.; Kim, C.; Marsik, M.; Spiridonov, G.; Toft, J.; Ruckelshaus, M.; Guerry, A.; Plummer, M.

    2011-12-01

    Humans obtain numerous benefits from marine ecosystems, including fish to eat; mitigation of storm damage; nutrient and water cycling and primary production; and cultural, aesthetic and recreational values. However, managing these benefits, or ecosystem services, in the marine world relies on an integrated approach that accounts for both marine and watershed activities. Here we present the results of a set of simple, physically-based, and spatially-explicit models that quantify the effects of terrestrial activities on marine ecosystem services. Specifically, we model the circulation and water quality of Hood Canal, WA, USA, a fjord system in Puget Sound where multiple human uses of the nearshore ecosystem (e.g., shellfish aquaculture, recreational Dungeness crab and shellfish harvest) can be compromised when water quality is poor (e.g., hypoxia, excessive non-point source pollution). Linked to the estuarine water quality model is a terrestrial hydrology model that simulates streamflow and nutrient loading, so land cover and climate changes in watersheds can be reflected in the marine environment. In addition, a shellfish aquaculture model is linked to the water quality model to test the sensitivity of the ecosystem service and its value to both terrestrial and marine activities. The modeling framework is general and will be publicly available, allowing easy comparisons of watershed impacts on marine ecosystem services across multiple scales and regions.

  15. Monaco and marine environmental protection

    International Nuclear Information System (INIS)

    Grimaldi, Albert II Prince

    2006-01-01

    The importance of the protection of the marine environment for sustainable development and economy of coastal countries, like Monaco, is well known. Sadly, this environment has been under continuous threats from development, tourism, urbanisation and demographic pressure. The semi-enclosed Mediterranean sea is challenged by new pollutant cocktails, problems of fresh water management, over-fishing, and now increasingly climate change impacts. Monaco has a long history in the investigation of the marine environment. Prince Albert I, was one of the pioneers in oceanographic exploration, organizer of European oceanographic research and founder of several international organizations including the Musee Oceanographique. The International Atomic Energy Agency established in 1961 its Marine Environment Laboratory in Monaco, the only marine laboratory in the United Nations system. More than 40 years ago the IAEA joined forces with the Grimaldi family and several interested governments to establish the Marine Environment Laboratory in Monaco. Their first purpose-built facilities, dedicated to marine research, launched a new era in the investigation of the marine environment using radioactive and stable isotopes as tracers for better understanding of processes in the oceans and seas, addressing their pollution and promoting wide international cooperation. The Government of the Principality of Monaco has been actively engaged in these developments and is continuously supporting activities of the Monaco Laboratory

  16. Marine04 marine radiocarbon age calibration, 0-26 cal kyr BP

    NARCIS (Netherlands)

    Hughen, Konrad A.; Baillie, Mike G.L.; Bard, Edouard; Beck, J. Warren; Bertrand, Chanda J.H.; Blackwell, Paul G.; Buck, Caitlin E.; Burr, George S.; Cutler, Kirsten B.; Damon, Paul E.; Edwards, Richard L.; Fairbanks, Richard G.; Friedrich, Michael; Guilderson, Thomas P.; Kromer, Bernd; McCormac, Gerry; Manning, Sturt; Bronk Ramsey, Christopher; Reimer, Paula J.; Reimer, Ron W.; Remmele, Sabine; Southon, John R.; Stuiver, Minze; Talamo, Sahra; Taylor, F.W.; Plicht, Johannes van der; Weyhenmeyer, Constanze E.

    2004-01-01

    New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration data sets extend an additional 2000 yr, from 0–26 cal kyr BP (Before Present, 0 cal BP = AD 1950), and

  17. Marine Science and Education in one Word: "planeetzee.org"

    Science.gov (United States)

    Seys, J.; Copejans, E.; Ameije, K.

    2009-04-01

    neighbourhood. Every answer is found on the website and consists of an animated lecture with pictures, movies, diagrams, simulations, etc.), followed by exercises, hints for field excursions, laboratory experiments, interactive games, etc. The seven major themes worked out in this project are derived from the ESF-Marine Board position paper on future marine research "Navigating the Future III": climate-ocean interactions, biodiversity, living and non-living resources, oceans and society, physical oceanography, harbours and shipping. The 21 topics are spread over the coastal areas, shallow seas and deep ocean habitats of the Atlantic, and make use of the best possible scientific know-how in Belgium and abroad. By providing 21 topics and more than 80 practical exercises, ‘Planeet Zee' hopes to present a challenging format for students and teachers in biology, physics, chemistry and geography (all levels for students as from 16 years). For marine scientists, it may well be a perfect way to have their know-how translated to a young public within a school context.

  18. Proceedings of the Franco-British Marine Energies Seminar

    International Nuclear Information System (INIS)

    Rufenacht, Antoine; Holmes, John; Moore, Alan; David, Pierre; Dal Ferro, Benoit; Shanahan, Gary; Bal, Jean-Louis; Ruer, Jacques; Laleu, Vincent de; Dupard, Dominique; Smith, George; Vandenbroucke, Eric; Bahaj, Abubakr; Le Guen, Yone; Mill, Andrew; Kermode, Neil; Taylor, Alan; Rousset, Jean Marc; Brossard, Jerome; Rawlinson Smith, Rob; Hassan, Garrad; Facon, Guy; Clement, Alain; Carcas, Max; Babarit, Aurelien; Ruellan, Marie; Langston, David; Crow, Nigel; Dreau, Guillaume; Cooper, Bill; Jenner, Chris; Abonnel, Cyrille; Fraenkel, Peter; Majastre, Herve; Imbault, Didier; Pagot, Jean Philippe; Huxley-Reynard, Chris; Auty, Fiona; Hughes, Gareth; Adrian, David; Starling, Michael; Eyraud, Delphine; Cochevelou, Gilles; Vallat, Francis; Operto, Gianni; Boston, Jon; Chrupek, Thierry; Mocilnikar, Tristan; Cassin, Fabrice; Gouverneur, Philippe; Lrivain, Alain; Perrot, Jean-Yves; Paillard, Michael; Sibun, Giles; Le Lann, Gilbert; Schirmann-Duclos, Danielle; Populus, Jacques; Maheut, Alexis; Lesieur, Christopher; Delgery, Chloe; Crutchfield, Zoe; David, Pierre; Abonnel, Cyril; Cochevelou, Gilles; Sibun, Giles; Crutchfield, Zoe

    2006-01-01

    This document brings together the available presentations (slides) made during this French-British seminar on Marine Energies. Content: 1 - Session I - Wave and Tidal, Prospects and Policy: Introduction (Pierre David); Wave and Tidal Resources - the scale of the opportunity (Benoit Dal Ferro); UK Policy and European Programmes (Gary Shanahan); French Policy on New and Renewable Energies (Jean-Louis Bal); Marine Energies and French Policy (Jacques Ruer, Vincent de Laleu); New Paths Towards Sustainable Energy (Dominique Dupard); 2 - Session II - Centres of Excellence in Research, Testing and Infrastructure: Introduction (George Smith, Eric Vandenbroucke); R and D - Universities and Companies in the UK (Abubakr Bahaj); METRI, A European infrastructure for research and testing on hydrodynamic behaviour of structure and ages of materials in marine environments (Yone Le Guen); 1/10 Scale Wave Tank Testing (Andrew Mill); Full Scale Testing (Neil Kermode); Long Term Monitoring (Alan Taylor); Experimental Methods and Numerical Simulation (Jean Marc Rousset); Modelling (Jerome Brossard, Rob Rawlinson Smith); Mediterranean Testing Centres (Guy Facon); 3 - Session III - Practitioners and Business Development - Wave Energy: Introduction (Alain Clement, Max Carcas, Aurelien Babarit, Marie Ruellan, David Langston, Nigel Crow, Guillaume Dreau, Bill Cooper, Chris Jenner); 4 - Session IV - Practitioners and Business Development - Current Energy: Introduction (Cyrille Abonnel, Peter Fraenkel, Herve Majastre, Didier Imbault, Jean Philippe Pagot, Chris Huxley-Reynard, Fiona Auty, Gareth Hughes, David Adrian, Michael Starling); 5 - Session V - Economics and Financing of Wave and Marine Energy Conversion: Introduction (Delphine Eyraud, Gilles Cochevelou); Role of French Cluster (Francis Vallat); Funding Panorama (Gianni Operto); The Technologist's Experience (Max Carcas); The Utility's Perspective (Jon Boston); French Methods and Policies for Development (Thierry Chrupek

  19. Simulating calving-front changes of Greenland’s marine-terminating glaciers

    DEFF Research Database (Denmark)

    Haubner, Konstanze

    glacier retreat to a certain degree and foremost define the variation of retreat rates. The thesis implies the importance of incorporating glacier-front dynamics into ice sheet models in order to match observations and verifies atmospheric and oceanic forcing as important triggers for glacier retreat...... UI outlet glaciers. The change in mass flux resulting from the prescribed glacier retreat contributes to 70% of UI’s mass change over the simulation periods. The residual mass change is due to surface mass balance. A second simulation on the fastest UI glacier (UI-1) reveals that frontal melt rates...

  20. Marine biodiversity in Japanese waters.

    Directory of Open Access Journals (Sweden)

    Katsunori Fujikura

    Full Text Available To understand marine biodiversity in Japanese waters, we have compiled information on the marine biota in Japanese waters, including the number of described species (species richness, the history of marine biology research in Japan, the state of knowledge, the number of endemic species, the number of identified but undescribed species, the number of known introduced species, and the number of taxonomic experts and identification guides, with consideration of the general ocean environmental background, such as the physical and geological settings. A total of 33,629 species have been reported to occur in Japanese waters. The state of knowledge was extremely variable, with taxa containing many inconspicuous, smaller species tending to be less well known. The total number of identified but undescribed species was at least 121,913. The total number of described species combined with the number of identified but undescribed species reached 155,542. This is the best estimate of the total number of species in Japanese waters and indicates that more than 70% of Japan's marine biodiversity remains un-described. The number of species reported as introduced into Japanese waters was 39. This is the first attempt to estimate species richness for all marine species in Japanese waters. Although its marine biota can be considered relatively well known, at least within the Asian-Pacific region, considering the vast number of different marine environments such as coral reefs, ocean trenches, ice-bound waters, methane seeps, and hydrothermal vents, much work remains to be done. We expect global change to have a tremendous impact on marine biodiversity and ecosystems. Japan is in a particularly suitable geographic situation and has a lot of facilities for conducting marine science research. Japan has an important responsibility to contribute to our understanding of life in the oceans.

  1. Model Simulations of a Mesocosm Experiment Investigating the Response of a Low Nutrient Low Chlorophyll (LNLC Marine Ecosystem to Atmospheric Deposition Events

    Directory of Open Access Journals (Sweden)

    Kostas P. Tsiaras

    2017-05-01

    Full Text Available Atmospheric deposition of nitrogen and phosphorus represents an important source of nutrients, enhancing the marine productivity in oligotrophic areas, e.g., the Mediterranean. A comprehensive biogeochemical model (ERSEM was setup and customized to simulate a mesocosm experiment, where dissolved inorganic nitrogen and phosphorus by means of atmospheric dust (single addition/SA and repetitive addition/RA in three successive doses was added in controlled tanks and compared with a control (blank, all with Cretan Sea (Eastern Mediterranean water. Observations on almost all components of the pelagic ecosystem in a ten-day period allowed investigating the effect of atmospheric deposition and the pathways of the added nutrients. The model was able to reasonably capture the observed variability of different ecosystem components and reproduce the main features of the experiment. An enhancement of primary production and phytoplankton biomass with added nutrients was simulated, in agreement with observations. A significant increase of bacterial production was also reproduced, while the model underestimated the observed increase and variability in bacterial biomass, but this deviation could be partly removed considering a lower carbon conversion factor from cell abundance data. A slightly stronger overall response was simulated with the single dust addition, compared to the repetitive that showed a few days delay. The simulated carbon pathways indicated that nutrient additions did not modify the microbial food web structure, but just increased its trophic status. Changes in model assumptions and parameter set that were necessary to reproduce the observed variability in the mesocosm experiment were discussed through a series of sensitivity simulations. Bacterial production was assumed to be mostly affected by the in situ produced labile organic matter, while it was further stimulated by the addition of inorganic nutrients, adopting a function of external

  2. Marine Ecosystem Services

    DEFF Research Database (Denmark)

    Hasler, Berit; Ahtiainen, Heini; Hasselström, Linus

    MARECOS (Marine Ecosystem Services) er et tværfagligt studie, der har haft til formål at tilvejebringe information vedrørende kortlægning og værdisætning af økosystemtjenester, som kan anvendes i forbindelse med udformning af regulering på det marine område såvel nationalt, som regionalt og inter...

  3. A subgrid parameterization scheme for precipitation

    Directory of Open Access Journals (Sweden)

    S. Turner

    2012-04-01

    Full Text Available With increasing computing power, the horizontal resolution of numerical weather prediction (NWP models is improving and today reaches 1 to 5 km. Nevertheless, clouds and precipitation formation are still subgrid scale processes for most cloud types, such as cumulus and stratocumulus. Subgrid scale parameterizations for water vapor condensation have been in use for many years and are based on a prescribed probability density function (PDF of relative humidity spatial variability within the model grid box, thus providing a diagnosis of the cloud fraction. A similar scheme is developed and tested here. It is based on a prescribed PDF of cloud water variability and a threshold value of liquid water content for droplet collection to derive a rain fraction within the model grid. Precipitation of rainwater raises additional concerns relative to the overlap of cloud and rain fractions, however. The scheme is developed following an analysis of data collected during field campaigns in stratocumulus (DYCOMS-II and fair weather cumulus (RICO and tested in a 1-D framework against large eddy simulations of these observed cases. The new parameterization is then implemented in a 3-D NWP model with a horizontal resolution of 2.5 km to simulate real cases of precipitating cloud systems over France.

  4. Location Accuracy of INS/Gravity-Integrated Navigation System on the Basis of Ocean Experiment and Simulation.

    Science.gov (United States)

    Wang, Hubiao; Wu, Lin; Chai, Hua; Bao, Lifeng; Wang, Yong

    2017-12-20

    An experiment comparing the location accuracy of gravity matching-aided navigation in the ocean and simulation is very important to evaluate the feasibility and the performance of an INS/gravity-integrated navigation system (IGNS) in underwater navigation. Based on a 1' × 1' marine gravity anomaly reference map and multi-model adaptive Kalman filtering algorithm, a matching location experiment of IGNS was conducted using data obtained using marine gravimeter. The location accuracy under actual ocean conditions was 2.83 nautical miles (n miles). Several groups of simulated data of marine gravity anomalies were obtained by establishing normally distributed random error N ( u , σ 2 ) with varying mean u and noise variance σ 2 . Thereafter, the matching location of IGNS was simulated. The results show that the changes in u had little effect on the location accuracy. However, an increase in σ 2 resulted in a significant decrease in the location accuracy. A comparison between the actual ocean experiment and the simulation along the same route demonstrated the effectiveness of the proposed simulation method and quantitative analysis results. In addition, given the gravimeter (1-2 mGal accuracy) and the reference map (resolution 1' × 1'; accuracy 3-8 mGal), location accuracy of IGNS was up to reach ~1.0-3.0 n miles in the South China Sea.

  5. Consumer Preferences Toward Marine Tourism Area

    Directory of Open Access Journals (Sweden)

    Silvy Fauziah

    2012-09-01

    Full Text Available The marine zone tourism is growing attracting more tourists. Pramuka Island is marine conservation area enriched with marine biodiversity in coral reefs and other natural resources. To develop this potential tourist destination, a customer-based marketing program is required to attract domestic and foreign tourists. The main vision is to understand tourist preferences for marine tourism activities and facilities. A research was conducted on Pramuka Island as a well-known marine tourism zone. The objective was to determine the key tourist preferences for marine tourism destination. Research methods utilized Cochran Q test and Conjoint analysis where the primary data were obtained from tourist respondents. The result showed that there was a tourist preference based on the five attributes considered most important, namely tourism activities, tourist attractions, types of accommodation, food and souvenirs types. This study provided marine tourism destination management with useful guidance for broader implications of the implementation of marketing programs and tourism attraction. Moreover, the results of this study consolidated the learning of a variety of academic and industrial research papers in particular for the measurement of customer preferences towards marine tourism destination.

  6. The Use of Stimulable Bioluminescence from Marine Dinoflagellates as a Means of Detecting Toxicity in the Marine Environment

    Science.gov (United States)

    1993-04-01

    FROM MARINE PR: ME65 DINOFLAGELLATES AS A MEANS OF DETECTING TOXICITY IN THE PE: 060372N MARINE ENVIRONMENT WU: DN288604 6ý AUTHOR(S) Accesion For I...measure the acute and sublethal effects of heavy metals ( tributyltin , copper, and zinc) and storm drain effluent on the light output from marine...Grovhoug 3 THE USE OF STIM1ULABLE BIOLUMINESCENCE FROM MARINE DINOFLAGELLATES AS A MEANS OF DETECTING TOXICITY IN THE MARINE ENVIRONMENT. REFERENCE

  7. Global distribution and climate forcing of marine organic aerosol: 1. Model improvements and evaluation

    Directory of Open Access Journals (Sweden)

    N. Meskhidze

    2011-11-01

    Full Text Available Marine organic aerosol emissions have been implemented and evaluated within the National Center of Atmospheric Research (NCAR's Community Atmosphere Model (CAM5 with the Pacific Northwest National Laboratory's 7-mode Modal Aerosol Module (MAM-7. Emissions of marine primary organic aerosols (POA, phytoplankton-produced isoprene- and monoterpenes-derived secondary organic aerosols (SOA and methane sulfonate (MS are shown to affect surface concentrations of organic aerosols in remote marine regions. Global emissions of submicron marine POA is estimated to be 7.9 and 9.4 Tg yr−1, for the Gantt et al. (2011 and Vignati et al. (2010 emission parameterizations, respectively. Marine sources of SOA and particulate MS (containing both sulfur and carbon atoms contribute an additional 0.2 and 5.1 Tg yr−1, respectively. Widespread areas over productive waters of the Northern Atlantic, Northern Pacific, and the Southern Ocean show marine-source submicron organic aerosol surface concentrations of 100 ng m−3, with values up to 400 ng m−3 over biologically productive areas. Comparison of long-term surface observations of water insoluble organic matter (WIOM with POA concentrations from the two emission parameterizations shows that despite revealed discrepancies (often more than a factor of 2, both Gantt et al. (2011 and Vignati et al. (2010 formulations are able to capture the magnitude of marine organic aerosol concentrations, with the Gantt et al. (2011 parameterization attaining better seasonality. Model simulations show that the mixing state of the marine POA can impact the surface number concentration of cloud condensation nuclei (CCN. The largest increases (up to 20% in CCN (at a supersaturation (S of 0.2% number concentration are obtained over biologically productive ocean waters when marine organic aerosol is assumed to be externally mixed with sea-salt. Assuming

  8. Effect of pre- and post-marination aging on meat quality attributes of early deboned (2 h postmortem) broiler breast fillets.

    Science.gov (United States)

    Kuttappan, V A; Gunsaulis, V B; Mauromoustakos, A; Meullenet, J F; Owens, C M

    2016-11-01

    Marination is an effective method that can be used to improve the tenderness of early deboned breast fillets. The present study was designed to evaluate the effect of pre- and post-marination aging of 2 h postmortem (PM) deboned chicken fillets to get optimum meat quality. In this study, a total of 300 broilers (43 to 46 d of age) were processed using an in-line system and deboned at 2 h PM. Fillets were marinated, at either 2.5, 4, 6, 8 or 24 h PM, using vacuum tumbling (20 min) with a 15% marinade (final concentration of 0.5% salt and 0.45% phosphate). A non-marinated control (CON) was included. The left (HOLD) fillets were aged (held at 4°C for 24 h) prior to freezing post-marination while the right (NO HOLD) fillets were frozen immediately after marination to simulate various commercial practices. Marination pickup (MPU), total marinade retained after thawing (TMR), total purge loss after thawing (TPL), cook loss (CL), and Meullenet-Owens Razor Shear energy (MORSE) values were measured. Both in HOLD and NO HOLD fillets, there was an increase (P water holding capacity. However, both in HOLD and NO HOLD groups, the MORSE values for the marinated fillets decreased (P retention as well as tenderness (or lower shear values). © 2016 Poultry Science Association Inc.

  9. NODC Standard Format Marine Mammals of Coastal Alaska Data (1975-1981): Marine Mammal Specimens (F025) (NODC Accession 0014150)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC maintains data in three NODC Standard Format Marine Mammal Data Sets: Marine Mammal Sighting and Census (F127); Marine Mammal Specimens (F025); Marine Mammal...

  10. Marine-Design Education

    DEFF Research Database (Denmark)

    Andersen, Poul; Birmingham, R.; Sortland, B.

    2006-01-01

    This report addresses Marine-Design Education in view of present and forecasted demands of the maritime industry, determined by a drastically transforming economic and technological maritime environment. In this framework, this report discusses in depth IT-based Marine Design education (par. 4......) and reveals innovative educational concepts and initiatives, such as the EiT (Experts in a Team) concept (par. 3), the SFS (Student Friendly Software) initiative (par. 5), Education Driven Research (EDR, par. 6) and Research Based Education (RBE, par. 6). Nevertheless, the paper stresses the need...... for continuity between traditional and modern ways of teaching (par. 4) and points out that Marine Design education is not only about Design, but should also address project/business administration and decision making issues (par. 7)....

  11. CMSMAP : oil, chemical, search and rescue, and marine emergency response crisis management system

    International Nuclear Information System (INIS)

    Anderson, E.L.; Howlett, E.; Galagan, C.; Giguere, T.; Wee, F.; Chong, J.

    2002-01-01

    This paper describes a newly developed Crisis Management System (CMS) which makes it possible to view oil and chemical spills on the seafloor. The CMS is designed to run in a network environment, so that multiple stations can be used cooperatively to respond to a spill incident. It was developed by the Maritime and Port Authority in Singapore and represents a singular integration of a ship's bridge simulator hardware and software. It incorporates numerical models and emergency response software. The CMS is installed in a specifically designed building at the Singapore Polytechnic University, and is integrated with two shipping bridge simulators. One user interface has access to models dealing with oil spills, chemical spills, search and rescues, marine emergencies, and nuclear disasters. The interface is linked to a response management system. The entire system is used to train response personnel to marine emergencies. The histories and costs of planned response activities are described and logged for reference purposes. Estimates of damages associated with spills can be obtained. Alternative response plans can also be determined. Further research in 2002 will focus on developing real time response. 3 refs., 6 figs

  12. Marine Mammal Protection Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Mammal Protection Act (MMPA or Act) prohibits, with certain exceptions, the "take" of marine mammals in U.S. waters and by U.S. citizens on the high seas,...

  13. Tsunamis and marine life

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.V.S.; Ingole, B.S.; Tang, D.; Satyanarayan, B.; Zhao, H.

    The 26 December 2004 tsunami in the Indian Ocean exerted far reaching temporal and spatial impacts on marine biota. Our synthesis was based on satellite data acquired by the Laboratory for Tropical Marine Environmental Dynamics (LED) of the South...

  14. Marine Litter, Eutrophication and Noise Assessment Tools

    Science.gov (United States)

    Palazov, Atanas; Velcheva, Maya; Milkova, Tanya; Slabakova, Violeta; Marinova, Veselka

    2017-04-01

    MARLEN - Marine Litter, Eutrophication and Noise Assessment Tools is a project under the Programme BG02.03: Increased capacity for assessing and predicting environmental status in marine and inland waters, managed by Bulgarian Ministry of environment and waters and co-financed by the Financial Mechanism of the European Economic Area (EEA FM) 2009 - 2014. Project Beneficiary is the Institute of oceanology - Bulgarian Academy of Sciences with two partners: Burgas municipality and Bulgarian Black Sea Basin Directorate. Initial assessment of ecological state of Bulgarian marine waters showed lack of data for some descriptors of MSFD. The main goal of MARLEN is to build up tools for assessment of marine environment by implementing new technologies and best practices for addressing three main areas of interest with lack of marine data in particular: a) Marine litter detection and classification in coastal areas; b) Regular near real time surface water eutrophication monitoring on large aquatory; c) Underwater noise monitoring. Developed tools are an important source of real time, near real time and delay mode marine data for Bulgarian Black Sea waters. The partnership within the project increased capacity for environmental assessments and training of personnel and enhances collaboration between scientific institutes, regional and local authorities. Project results supported implementation of MSFD in Bulgarian marine waters for the benefit of coastal population, marine industry, tourism, marine research and marine spatial planning.

  15. Real-Time Simulation of Ship Impact for Crew Training

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    2003-01-01

    Real-time simulation of marine accidents and representation in a realistic, virtual environment may be an efficient way to train emergency procedures for ship?s crews and thus improve safety at sea. However, although various fast, simplified methods have been presented over the past decades...

  16. Marine Oil-Degrading Microorganisms and Biodegradation Process of Petroleum Hydrocarbon in Marine Environments: A Review.

    Science.gov (United States)

    Xue, Jianliang; Yu, Yang; Bai, Yu; Wang, Liping; Wu, Yanan

    2015-08-01

    Due to the toxicity of petroleum compounds, the increasing accidents of marine oil spills/leakages have had a significant impact on our environment. Recently, different remedial techniques for the treatment of marine petroleum pollution have been proposed, such as bioremediation, controlled burning, skimming, and solidifying. (Hedlund and Staley in Int J Syst Evol Microbiol 51:61-66, 2001). This review introduces an important remedial method for marine oil pollution treatment-bioremediation technique-which is considered as a reliable, efficient, cost-effective, and eco-friendly method. First, the necessity of bioremediation for marine oil pollution was discussed. Second, this paper discussed the species of oil-degrading microorganisms, degradation pathways and mechanisms, the degradation rate and reaction model, and the factors affecting the degradation. Last, several suggestions for the further research in the field of marine oil spill bioremediation were proposed.

  17. 77 FR 58255 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey off the...

    Science.gov (United States)

    2012-09-19

    ... requirements, many marine animals may need to remain in areas where they are exposed to chronic stimuli... Vol. 77 Wednesday, No. 182 September 19, 2012 Part III Department of Commerce Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey off the Central Coast of California...

  18. 78 FR 52135 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental To...

    Science.gov (United States)

    2013-08-22

    ...--Marine Mammal Density Estimates Density Species (animals/km \\2\\) Bottlenose dolphin \\1\\ 0.455 Atlantic... criteria and thresholds in a final rule on the unintentional taking of marine animals occurring incidental... analysis assumed the marine species populations were 100 percent small animals. The criterion with the...

  19. Marine Battlefields

    DEFF Research Database (Denmark)

    Harðardóttir, Sara

    as they are an important food source for various marine animals. For both phytoand zooplankton predation is a major cause of mortality, and strategies for protection or avoidance are important for survival. Diatoms of the genera Nitzschia and Pseudo-nitzschia are known to produce a neuro-toxin, domoic acid (DA). Despite......Phytoplankton species are photosynthetic organisms found in most aquatic habitats. In the ocean, phytoplankton are tremendously important because they produce the energy that forms the base of the marine food web. Zooplankton feed on phytoplankton and mediate the energy to higher trophic levels...

  20. Marine debris removal: one year of effort by the Georgia Sea Turtle-Center-Marine Debris Initiative.

    Science.gov (United States)

    Martin, Jeannie Miller

    2013-09-15

    Once in the marine environment, debris poses a significant threat to marine life that can be prevented through the help of citizen science. Marine debris is any manufactured item that enters the ocean regardless of source, commonly plastics, metal, wood, glass, foam, cloth, or rubber. Citizen science is an effective way to engage volunteers in conservation initiatives and provide education and skill development. The Georgia Sea Turtle Center Marine Debris Initiative (GSTC-MDI) is a grant funded program developed to engage citizens in the removal of marine debris from the beaches of Jekyll Island, GA, USA and the surrounding areas. During the first year of effort, more than 200 volunteers donated over 460 h of service to the removal of marine debris. Of the debris removed, approximately 89% were plastics, with a significant portion being cigarette materials. Given the successful first year, the GSTC-MDI was funded again for a second year. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Economic growth and marine biodiversity: influence of human social structure on decline of marine trophic levels.

    Science.gov (United States)

    Clausen, Rebecca; York, Richard

    2008-04-01

    We assessed the effects of economic growth, urbanization, and human population size on marine biodiversity. We used the mean trophic level (MTL) of marine catch as an indicator of marine biodiversity and conducted cross-national time-series analyses (1960-2003) of 102 nations to investigate human social influences on fish catch and trends in MTL. We constructed path models to examine direct and indirect effects relating to marine catch and MTL. Nations' MTLs declined with increased economic growth, increased urbanization, and increased population size, in part because of associated increased catch. These findings contradict the environmental Kuznets curve hypothesis, which claims that economic modernization will reduce human impact on the environment. To make informed decisions on issues of marine resource management, policy makers, nonprofit entities, and professional societies must recognize the need to include social analyses in overall conservation-research strategies. The challenge is to utilize the socioeconomic and ecological research in the service of a comprehensive marine-conservation movement.

  2. Strengthened enforcement enhances marine sanctuary performance

    Directory of Open Access Journals (Sweden)

    Brendan P. Kelaher

    2015-01-01

    Full Text Available Marine sanctuaries are areas where the extraction of biota is not permitted. Although most marine sanctuaries have a positive influence on biotic communities, not all sanctuaries are meeting their conservation objectives. Amidst possible explanations (e.g., size, age and isolation, insufficient enforcement is often speculated to be a key driver of marine sanctuary underperformance. Despite this, there are few studies directly linking quantitative enforcement data to changes in biotic communities within marine sanctuaries. Here, we used an asymmetrical-BACI experimental design from 2006–2012 to test whether new enforcement initiatives enhanced abundances of target fishes and threatened species in an existing large sub-tropical marine sanctuary relative to areas open to fishing. Implementation of the new enforcement initiatives in 2010 was associated with a 201% increase in annual fine rate and a significant increase in target fish and elasmobranch abundance, as well as sightings of a critically-endangered shark, in the marine sanctuary relative to areas open to fishing. Overall, these results demonstrate that strengthening enforcement can have a rapid positive influence on target fish and perhaps threatened species in a subtropical marine sanctuary. From this, we contend that increased enforcement guided by risk-based compliance planning and operations may be a useful first step for improving underperforming marine sanctuaries.

  3. Marine spatial planning in Cyprus

    Science.gov (United States)

    Hadjimitsis, Diofantos; Agapiou, Athos; Mettas, Christodoulos; Themistocleous, Kyriacos; Evagorou, Evagoras; Cuca, Branka; Papoutsa, Christiana; Nisantzi, Argyro; Mamouri, Rodanthi-Elisavet; Soulis, George; Xagoraris, Zafiris; Lysandrou, Vasiliki; Aliouris, Kyriacos; Ioannou, Nicolas; Pavlogeorgatos, Gerasimos

    2015-06-01

    Marine Spatial Planning (MSP), which is in concept similar to land-use planning, is a public process by which the relevant Member State's authorities analyse and organise human activities in marine areas to achieve ecological, economic and social objectives. MSP aims to promote sustainable growth of maritime economies, sustainable development of marine areas and sustainable use of marine resources. This paper highlights the importance of MSP and provides basic outcomes of the main European marine development. The already successful MSP plans can provide useful feedback and guidelines for other countries that are in the process of implementation of an integrated MSP, such as Cyprus. This paper presents part of the MSP project, of which 80% funded by the European Regional Development Fund (ERDF) and 20% from national contribution. An overview of the project is presented, including data acquisition, methodology and preliminary results for the implementation of MSP in Cyprus.

  4. Modelling of Combustion and Pollutant Formation in a Large, Two-Stroke Marine Diesel Engine using Integrated CFD-Skeletal Chemical Mechanism

    DEFF Research Database (Denmark)

    Pang, Kar Mun; Karvounis, Nikolas; Schramm, Jesper

    In this reported work, simulation studies of in-cylinder diesel combustion and pollutant formation processesin a two-stroke, low-speed uniflow-scavenged marine diesel engine are presented. Numerical computation is performed by integrating chemical kinetics into CFD computations. In order...... to minimize the computational runtime, an in-house skeletal n-heptane chemical mechanism is coupled with the CFD model. This surrogate fuel model comprises 89 reactions with 32 species essential to diesel ignition/combustion processes as well as the formation of soot precursors and nitrogen monoxide (NO......). Prior to the marine engine simulation,coupling of the newly developed surrogate fuel model and a revised multi-step soot model [1] is validated on the basis of optical diagnostics measurement obtained at varying ambient pressure levels [2]. It is demonstrated that the variation of ignition delay times...

  5. Descriptive sensory analysis of marinated and non-marinated wooden breast fillet portions.

    Science.gov (United States)

    Maxwell, A D; Bowker, B C; Zhuang, H; Chatterjee, D; Adhikari, K

    2018-05-14

    The wooden breast (WB) myopathy influences muscle composition and texture characteristics in broiler breast meat. It is unknown if marination reduces the negative influence of WB on meat sensory quality or if WB effects are uniform throughout the Pectoralis major. The objective of this study was to determine the effects of marination on the sensory attributes and instrumental shear force measurements of the ventral (skin-side) and dorsal (bone-side) portions of normal and severe WB meat. Sixty butterfly fillets (30 normal and 30 severe WB) were selected from the deboning line of a commercial processing plant. Individual fillets were portioned into ventral and dorsal halves. Portions from one side of each butterfly were used as non-marinated controls, and portions from the other side were vacuum-tumble marinated (16 rpm, -0.6 atm, 4°C, 20 min) with 20% (wt/wt) marinade to meat ratio. Marinade was formulated to target a concentration of 0.75% (w/v) salt and 0.45% (w/v) sodium tripolyphosphate in the final product. Descriptive sensory analysis (9 trained panelists) was conducted to evaluate visual, texture, and flavor attributes (0-15 point scale) of breast portions along with Warner-Bratzler shear force. Significant interaction effects between WB and marination were not observed for the sensory attributes. Greater springiness, cohesiveness, hardness, fibrousness, and chewiness scores were observed in WB samples (P sensory texture attributes were more apparent in the ventral portions of the breast fillets. Flavor attributes (salty and brothy) increased (P sensory quality is not uniform throughout the Pectoralis major and that WB-related differences in cooked meat sensory texture attributes are lessened but not eliminated by vacuum-tumbling marination.

  6. Marine conservation strategies for Maharashtra Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Dhargalkar, V.K.

    , Wildlife Sanctuaries, Marine Parks and Protected Areas. Detailed studies of 37 sites along the Maharashtra Coast, for their marine biota and also the ecological conditions, were taken up. Out of these, seven most luxuriant areas in marine biodiversity have...

  7. Promotion Factors For Enlisted Infantry Marines

    Science.gov (United States)

    2017-06-01

    Marine Corps. However, due to periods of growth during two major conflicts , quality has given way to quantity to fulfill the needs of the Marine...Corps. As conflicts draw down, the Marine Corps shifts from promoting and retaining quantity to high-quality Marines. Throughout this thesis, we use...historically possessed an innate drive to succeed, to excel in all that they do, including winning in combat. We will sustain this trait and ensure this

  8. Marine Corps Amphibious Combat Vehicle (ACV) and Marine Personnel Carrier (MPC): Background and Issues for Congress

    Science.gov (United States)

    2017-03-08

    the AAV, incorporating some EFV capabilities but in a more practical and cost-efficient manner . In concert with the ACV, the Marines were developing...EFV capabilities but in a more practical and cost-efficient manner . In concert with the ACV, the Marines were developing the Marine Personnel Carrier

  9. A global census of marine microbes

    Digital Repository Service at National Institute of Oceanography (India)

    Amaral-Zettler, L.; Artigas, L.F.; Baross, J.; LokaBharathi, P.A; Boetius, A; Chandramohan, D.; Herndl, G.; Kogure, K.; Neal, P.; Pedros-Alio, C.; Ramette, A; Schouten, S.; Stal, L.; Thessen, A; De Leeuw, J.; Sogin, M.

    In this chapter we provide a brief history of what is known about marine microbial diversity, summarize our achievements in performing a global census of marine microbes, and reflect on the questions and priorities for the future of the marine...

  10. Prediction of CO2 leakage during sequestration into marine sedimentary strata

    International Nuclear Information System (INIS)

    Li, Qi; Wu Zhishen; Li Xiaochun

    2009-01-01

    Deep ocean storage of CO 2 could help reduce the atmospheric level of greenhouse gas as part of a climate change mitigation strategy. In this paper, a multiphase flow model of CO 2 sequestration into deep ocean sediments was designed associated with the formation of CO 2 hydrates. A simplified assumption was proposed to predict the critical time of CO 2 leakage from marine sedimentary strata into seawater. Moreover, some principal parameters, which include the permeability, anisotropy, total injection amount, and length of the injection part of wellbores, were investigated by numerical simulations. The numerical estimates are used to assess the feasibility and effectiveness of CO 2 storage in deep ocean sediments. Accurately predicting the actual fate of liquid CO 2 sequestered into the marine sedimentary strata at depths greater than 500 m is complicated by uncertainties associated with not only the chemical-physical behavior of CO 2 under such conditions but also the geo-environment of disposal sites. Modeling results have shown some implications that the effectiveness of CO 2 ocean sequestration depends mainly on the injection conditions (such as injection rate, total injection amount, and the depth of injection), the site geology (such as permeability and anisotropy of disposal formations), and the chemical-physical behavior of CO 2 in marine environment

  11. Damage localization of marine risers using time series of vibration signals

    Science.gov (United States)

    Liu, Hao; Yang, Hezhen; Liu, Fushun

    2014-10-01

    Based on dynamic response signals a damage detection algorithm is developed for marine risers. Damage detection methods based on numerous modal properties have encountered issues in the researches in offshore oil community. For example, significant increase in structure mass due to marine plant/animal growth and changes in modal properties by equipment noise are not the result of damage for riser structures. In an attempt to eliminate the need to determine modal parameters, a data-based method is developed. The implementation of the method requires that vibration data are first standardized to remove the influence of different loading conditions and the autoregressive moving average (ARMA) model is used to fit vibration response signals. In addition, a damage feature factor is introduced based on the autoregressive (AR) parameters. After that, the Euclidean distance between ARMA models is subtracted as a damage indicator for damage detection and localization and a top tensioned riser simulation model with different damage scenarios is analyzed using the proposed method with dynamic acceleration responses of a marine riser as sensor data. Finally, the influence of measured noise is analyzed. According to the damage localization results, the proposed method provides accurate damage locations of risers and is robust to overcome noise effect.

  12. The Cost of SOx Limits to Marine Operators; Results from Exploring Marine Fuel Prices

    Directory of Open Access Journals (Sweden)

    Orestis Schinas

    2013-06-01

    Full Text Available Marine operators are confronted with the new air emissions regulations that determine the limits of sulfur content in marine fuels. The low-sulfur (LS marine fuels have a higher price, and their fluctuation is almost similar to the fluctuation of high-sulfur (HS fuels. The price difference between HS and LS might also determine the decision of operators for alternative technical means, such as scrubbers, in order to comply with the new limits. This paper aims to provide a thorough statistical analysis of the currently available LS and HS marine fuels time series, as well as to present the analysis of the differential of the HS and LS fuel prices. The paper concludes with suggestions for further research.

  13. A combination of quantitative marinating and Maillard reaction to enhance volatile flavor in Chinese marinated chicken.

    Science.gov (United States)

    Wei, Xiuli; Wang, Chunqing; Zhang, Chunhui; Li, Xia; Wang, Jinzhi; Li, Hai; Tang, Chunhong

    2017-02-01

    A combination of quantitative marinating and Maillard reaction was investigated by adding d-xylose, l-cysteine and thiamine to the marinated brine of quantitative marinating, which was expected to enhance the volatile flavor of Chinese marinated chicken. Response surface methodology was used to optimize parameters, in which response was sensory evaluation scores of marinated chicken. A Box-Behnken center design was applied to the optimized added contents. The optimized contents were d-xylose (1-5‰), l-cysteine (1-5‰) and thiamine (1-3‰). Analysis of variance indicated that a second-order polynomial equation could predict the experimental data well (R 2  = 0.94), and sensory evaluation scores were significantly affected by the added amount of d-xylose, l-cysteine and thiamine. The optimal conditions that maximized the sensory evaluation score of Chinese marinated chicken were found to be 4.96‰ d-xylose, 2.28‰ l-cysteine and 2.66‰ thiamine (w/w). Given these optimal conditions, a number of meat-like flavor compounds such as 2-pentyl-furan, benzothiazole and 4-methyl-5-thiazoleethanol were identified by gas chromatographic-mass spectrometric analysis. Our results suggested that a combination of quantitative marinating and Maillard reaction might be a promising method to enhance the volatile flavor, especially meat-like flavor, of Chinese marinated chicken. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Encyclopedic approach to Marine History of Russia

    Directory of Open Access Journals (Sweden)

    Andrey V. Ishin

    2017-01-01

    Full Text Available Marine direction of foreign policy is for Russia one of key. It is determined geographical position of the Russian state banks of which is washed plenty of Maureies. Also it is related to that considerable part of population lives on the coast of Russian Maureies, and industry, located in an off-shore bar brings, in a large contribution to the economy.Many Russian marine travelers were the discoverers of «new» earths. The contribution of the Russian scientists to the hydrophysical, geological and biological study of Maureies and Oceans is great. Russia possesses a navy, to the constituents approximately one-third of total tonnage of world VMF and one of large in the world a rybopromyslovym fleet. Transport ships under the flag of Russian Federation it is possible to meet planets in the remotest corners. In a number of areas of military shipbuilding and civil shipbuilding Russia had and continues to save priority.Enhanceable interest to the Seas and Oceans found the reflection in the fundamental Russian documents, including, in the Marine doctrine of Russian Federation, ratified Russia President in 2015. In it the value of marine spaces for the Russian state is marked. In the Marine doctrine of Russian Federation is writtenin: «The skilled providing, marine teaching and education play an important role in the increase of efficiency of marine activity. They are directed on preparation, bringing in and maintainance of skilled shots of all levels, maintenance of professionalism, marine traditions and not indifferent relation of citizens to marine history of country, serve positive presentation, propaganda and support of national marine policy, to marine activity and marine service in society».Marine direction, marine science about regions found a reflection in the publications of row of the Russian authors, devoted research of policy of Russia in such regions, as: Black Sea region, Caspian region, Arctic, and also in the series of Encyclopaedias

  15. The Speed Control of Constant Tension Motor of Marine Crane

    Directory of Open Access Journals (Sweden)

    Chen Xinyang

    2016-01-01

    Full Text Available This article describes the working principle of the marine beacon crane hanging disc mechanical anti-sway device, and establish mathematical model on the rope controlling hanging disc of mechanical anti-sway device; Through matlab simulation analysis, this article obtains the relation curve between the velocity of traction rope of hanging disc and output frequency of the crane motor, combining rotary crane scaled model, this article carries out anti-sway experiment for the rotary crane to examine the crane’s anti-sway effects.

  16. AMOP (Arctic Marine Oil Spill Program) studies reviewed

    Energy Technology Data Exchange (ETDEWEB)

    1978-06-05

    A discussion of the Arctic Marine Oil Spill Program organized in 1976 by the Canadian Federal Government includes: an Arctic Atlas compiled by Fenco Consultants Ltd. to give background information necessary for developing marine oil spill countermeasures for the Arctic north of 60/sup 0/ including the west Greenland coast and the Labrador shelf (geology, meteorology and oceanography, ice conditions, biology, and social factors); program in emergency transport of spill-combatting equipment; and the factors which influence the choice of conveyance, i.e., accessibility of the site, urgency for response, and quantity of material required; laboratory studies involving the release of oil under artificial sea ice in simulated ice formation and decay purposes to determine the interaction of crude oil and first-year sea ice; inability of companies and government to control a major spill in the Labrador Sea because of poor and inadequate transport facilities, communications, and navigational aids, severe environmental conditions, and logistics problems; and studies on the effects of oil-well blowouts in deep water, including formation of oil and gas hydrates, design of oil skimmers, the use of hovercraft, and specifications for an airborne multisensor system for oil detection in ice-infested waters.

  17. Using Diffraction Tomography to Estimate Marine Animal Size

    Science.gov (United States)

    Jaffe, J. S.; Roberts, P.

    In this article we consider the development of acoustic methods which have the potential to size marine animals. The proposed technique uses scattered sound in order to invert for both animal size and shape. The technique uses the Distorted Wave Born Approximation (DWBA) in order to model sound scattered from these organisms. The use of the DWBA also provides a valuable context for formulating data analysis techniques in order to invert for parameters of the animal. Although 3-dimensional observations can be obtained from a complete set of views, due to the difficulty of collecting full 3-dimensional scatter, it is useful to simplify the inversion by approximating the animal by a few parameters. Here, the animals are modeled as 3-dimensional ellipsoids. This reduces the complexity of the problem to a determination of the 3 semi axes for the x, y and z dimensions from just a few radial spokes through the 3-dimensional Fourier Transform. In order to test the idea, simulated scatter data is taken from a 3-dimensional model of a marine animal and the resultant data are inverted in order to estimate animal shape

  18. A GCM study of organic matter in marine aerosol and its potential contribution to cloud drop activation

    NARCIS (Netherlands)

    Roelofs, G.J.H.

    2007-01-01

    With the global aerosol-climate model ECHAM5-HAM we investigate the potential influence of organic aerosol originating from the ocean on aerosol mass and chemical composition and the droplet concentration and size of marine clouds. We present sensitivity simulations in which the uptake of organic

  19. Efficient management of marine resources in conflict: an empirical study of marine sand mining, Korea.

    Science.gov (United States)

    Kim, Tae-Goun

    2009-10-01

    This article develops a dynamic model of efficient use of exhaustible marine sand resources in the context of marine mining externalities. The classical Hotelling extraction model is applied to sand mining in Ongjin, Korea and extended to include the estimated marginal external costs that mining imposes on marine fisheries. The socially efficient sand extraction plan is compared with the extraction paths suggested by scientific research. If marginal environmental costs are correctly estimated, the developed efficient extraction plan considering the resource rent may increase the social welfare and reduce the conflicts among the marine sand resource users. The empirical results are interpreted with an emphasis on guidelines for coastal resource management policy.

  20. Marine palynology in progress

    NARCIS (Netherlands)

    Manten, A.A.

    1966-01-01

    One of the things which the Second International Conference on Palynology (held in Utrecht, August 29-September 3, 1966) revealed, was the rapid expansion which marine palynological research has undergone in recent years. This was the main stimulus to organize this special issue of Marine

  1. Antimycobacterial Metabolites from Marine Invertebrates.

    Science.gov (United States)

    Daletos, Georgios; Ancheeva, Elena; Chaidir, Chaidir; Kalscheuer, Rainer; Proksch, Peter

    2016-10-01

    Marine organisms play an important role in natural product-based drug research due to accumulation of structurally unique and bioactive metabolites. The exploration of marine-derived compounds may significantly extend the scientific knowledge of potential scaffolds for antibiotic drug discovery. Development of novel antitubercular agents is especially significant as the emergence of drug-resistant Mycobacterium tuberculosis strains remains threateningly high. Marine invertebrates (i.e., sponges, corals, gorgonians) as a source of new chemical entities are the center of research for several scientific groups, and the wide spectrum of biological activities of marine-derived compounds encourages scientists to carry out investigations in the field of antibiotic research, including tuberculosis treatment. The present review covers published data on antitubercular natural products from marine invertebrates grouped according to their biogenetic origin. Studies on the structure-activity relationships of these important leads are highlighted as well. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Seawater and marine sidements

    International Nuclear Information System (INIS)

    Eicke, H.F.

    1985-01-01

    The Deutsches Hydrographisches Institut (DHI) is responsible for monitoring the radioactive substances (such as Cs-137, Cs-134, Sr-90, H-3, Pu-239, Pu-240) in the seawater and marine sediments along the Federal German seacoasts, of the fishing grounds of the Federal German offshore fishery industry, and of marine currents moving towards these fishing grounds. The DHI has been carrying out this task since 1965, activities being placed under the responsibility of the DHI Department for Marine Radioactivity, which since 1960 is a directing centre within the Government's system for environmental radioactivity monitoring. (orig./DG) [de

  3. Will marine productivity wane?

    Science.gov (United States)

    Laufkötter, Charlotte; Gruber, Nicolas

    2018-03-01

    If marine algae are impaired severely by global climate change, the resulting reduction in marine primary production would strongly affect marine life and the ocean's biological pump that sequesters substantial amounts of atmospheric carbon dioxide in the ocean's interior. Most studies, including the latest generation of Earth system models, project only moderate global decreases in biological production until 2100 (1, 2), suggesting that these concerns are unwarranted. But on page 1139 of this issue, Moore et al. (3) show that this conclusion might be shortsighted and that there may be much larger long-term changes in ocean productivity than previously appreciated.

  4. Identification & Registration of Marine Animals (IRMA)

    NARCIS (Netherlands)

    Benders, F.P.A.; Zwan, T. van der; Verboom, W.C.

    2005-01-01

    Knowledge about habitats and behaviour of marine animals has become more important following an increased concern that acoustic sources may have an influence on marine life. Databases containing the habitats and behaviour are being filled all over the world. However, at present marine mammal

  5. Theory and Practice of Marine Regional Management in China

    Institute of Scientific and Technical Information of China (English)

    Shangjie; JI; Qunzhen; QU

    2014-01-01

    With the development of marine economy in coastal provinces and cities,there comes a series of environmental problems. Marine regional management,as a completely new marine management mode,transforms traditional management mode and can protect marine ecosystem. Thus,the marine regional management is feasible and applicable in China. This paper firstly discussed connotation and development of the marine regional management in China and pointed that the marine regional management is integrated management of a certain marine region. Next,it summarized characteristics of the marine regional management at current stage,for example,land-based pollution of trans-geographic system and marine management under regional government cooperative mechanism. Finally,it came up with recommendations including combining theory and practice of the marine regional management,and establishing marine regional management system as soon as possible,to realize benign interaction and sustainable development of marine economy and ecological environment.

  6. Neoproterozoic marine carbonates and their paleoceanographic significance

    Science.gov (United States)

    Hood, Ashleigh van Smeerdijk; Wallace, Malcolm William

    2018-01-01

    The primary mineralogy of marine carbonate precipitates has been a crucial factor in constraining the major element composition of ancient oceans. Secular changes in Phanerozoic marine chemistry, including Mg/Ca, have been well-documented using the original carbonate mineralogy of ooids, marine cements and biominerals. However, the history of Precambrian seawater chemistry is not as well constrained, partially due to the prevalence of dolomitisation in the Precambrian geological record. The Neoproterozoic ( 1000 Ma to 541 Ma) record of primary carbonate mineralogy is documented here using a combination of literature data and new analysis of marine carbonate precipitates from the Otavi Fold Belt, Namibia, the Death Valley succession, USA and the Adelaide Fold Belt, Australia. These data suggest that the last 460 million years of the Proterozoic were dominated by aragonite and high-Mg calcite precipitation in shallow marine settings. In contrast, low-Mg calcite has only been recognised in a small number of formations. In addition to aragonite and calcite precipitation, marine dolomite precipitation was widespread in Neoproterozoic oceans, including mimetic (syn-sedimentary) dolomitisation and primary dolomite marine cementation. The combination of marine aragonite, high Mg-calcite and dolomite precipitation during the Neoproterozoic suggests extremely high seawater Mg/Ca conditions relative to Phanerozoic oceans. Marine dolomite precipitation may also be linked to widespread marine anoxia during this time.

  7. Marine Shaft Steels (AISI 4140 and AISI 5120 Predicted Fracture Toughness by FE Simulation

    Directory of Open Access Journals (Sweden)

    Goran VUKELIC

    2017-02-01

    Full Text Available Optimal selection of material can be considered as one of the most critical steps in engineering design process. That is especially emphasized when dealing with constructions that operate in marine environment; high stresses and harsh operating conditions assert the importance of proper material characterization before its selection. This paper presents comparison of two types of steel usually used in marine shaft manufacturing, chromium-molybdenum steel AISI 4140 and chromium low-alloy steel AISI 5120. Comparison was made using numerically determined J-integral, an important fracture mechanics parameter. J-integral values are determined numerically using finite element (FE stress analysis results of compact tensile (CT and single-edge notched bend (SENB type specimens usually used in standardized J-integral experimental procedures. Obtained J values are plotted versus specimen crack growth values (Δa for different specimen geometries (a/W. Higher resulting values of J-integral for AISI 5120 than AISI 4140 can be noticed. Also, higher a/W ratios correspond to lower J-integral values of materials and vice versa. In addition to that, J-integral values obtained by using FE model of CT specimen give somewhat conservative results when compared with ones obtained by FE model of SENB specimen. Although this procedure differs from experimental analysis, results can be used a suitable fracture parameter value in fracture toughness assessment.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.13823

  8. NODC Standard Format Marine Mammals of Coastal Alaska Data (1975-1976): Marine Mammal Sighting 2 (F026) (NODC Accession 0014151)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC maintains data in three NODC Standard Format Marine Mammal Data Sets: Marine Mammal Sighting and Census (F127); Marine Mammal Specimens (F025); Marine Mammal...

  9. Simulating CO₂ leakages from CCS to determine Zn toxicity using the marine microalgae Pleurochrysis roscoffensis.

    Science.gov (United States)

    Bautista-Chamizo, Esther; De Orte, Manoela Romanó; DelValls, Tomás Ángel; Riba, Inmaculada

    2016-02-01

    Due to the current climate change and ocean acidification, a new technology for CO2 mitigation has been proposed, the Carbon dioxide Capture and Storage (CCS). However, there is an ecological risk associated with potential CO2 leakages from the sub-seabed storages sites. To evaluate the effects related to CO2 leakages, laboratory-scales experiments were performed using the marine microalgae Pleurochrysis roscoffensis. Five Zn concentrations were tested at different pHs to study Zn toxicity under acidified conditions. Seawater was collected and submitted to acidification by means of CO2 injection and by HCl addition. Results showed differences between both acidification techniques: while microalgae growth was enhanced by CO2 supply, reaching the optimal growth at pH 6.5 and full inhibition at pH 5.5, HCl acidification growth was inhibited at pH 6.5. Although small concentrations of Zn were positive for P. roscoffensis growth, Zn toxicity increased at lower pHs, and more severely on samples acidified with HCl. The conclusions obtained in this work are useful to address the potential effects on the marine ecosystem related to changes in metal bioavailability during CO2 leakages scenarios. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Environmental Guidance Program Reference Book: Marine Protection, Research, and Sanctuaries Act and Marine Mammal Protection Act. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-31

    Two laws governing activities in the marine environment are considered in this Reference Book. The Marine Protection, Research, and Sanctuaries Act (MPRSA, P.L. 92-532) regulates ocean dumping of waste, provides for a research program on ocean dumping, and provides for the designation and regulation of marine sanctuaries. The Marine Mammal Protection Act (MMPA, P.L. 92-522) establishes a federal program to protect and manage marine mammals. The Fishery Conservation and Management Act (FCMA, P.L. 94-265) establishes a program to regulate marine fisheries resources and commercial marine fishermen. Because the Department of Energy (DOE) is not engaged in any activities that could be classified as fishing under FCMA, this Act and its regulations have no implications for the DOE; therefore, no further consideration of this Act is given within this Reference Book. The requirements of the MPRSA and the MMPA are discussed in terms of their implications for the DOE.

  11. Comparing marine and terrestrial ecosystems: Implications for the design of coastal marine reserves

    Science.gov (United States)

    Carr, M.H.; Neigel, J.E.; Estes, J.A.; Andelman, S.; Warner, R.R.; Largier, J. L.

    2003-01-01

    Concepts and theory for the design and application of terrestrial reserves is based on our understanding of environmental, ecological, and evolutionary processes responsible for biological diversity and sustainability of terrestrial ecosystems and how humans have influenced these processes. How well this terrestrial-based theory can be applied toward the design and application of reserves in the coastal marine environment depends, in part, on the degree of similarity between these systems. Several marked differences in ecological and evolutionary processes exist between marine and terrestrial ecosystems as ramifications of fundamental differences in their physical environments (i.e., the relative prevalence of air and water) and contemporary patterns of human impacts. Most notably, the great extent and rate of dispersal of nutrients, materials, holoplanktonic organisms, and reproductive propagules of benthic organisms expand scales of connectivity among near-shore communities and ecosystems. Consequently, the "openness" of marine populations, communities, and ecosystems probably has marked influences on their spatial, genetic, and trophic structures and dynamics in ways experienced by only some terrestrial species. Such differences appear to be particularly significant for the kinds of organisms most exploited and targeted for protection in coastal marine ecosystems (fishes and macroinvertebrates). These and other differences imply some unique design criteria and application of reserves in the marine environment. In explaining the implications of these differences for marine reserve design and application, we identify many of the environmental and ecological processes and design criteria necessary for consideration in the development of the analytical approaches developed elsewhere in this Special Issue.

  12. Low Cloud Feedback to Surface Warming in the World's First Global Climate Model with Explicit Embedded Boundary Layer Turbulence

    Science.gov (United States)

    Parishani, H.; Pritchard, M. S.; Bretherton, C. S.; Wyant, M. C.; Khairoutdinov, M.; Singh, B.

    2017-12-01

    Biases and parameterization formulation uncertainties in the representation of boundary layer clouds remain a leading source of possible systematic error in climate projections. Here we show the first results of cloud feedback to +4K SST warming in a new experimental climate model, the ``Ultra-Parameterized (UP)'' Community Atmosphere Model, UPCAM. We have developed UPCAM as an unusually high-resolution implementation of cloud superparameterization (SP) in which a global set of cloud resolving arrays is embedded in a host global climate model. In UP, the cloud-resolving scale includes sufficient internal resolution to explicitly generate the turbulent eddies that form marine stratocumulus and trade cumulus clouds. This is computationally costly but complements other available approaches for studying low clouds and their climate interaction, by avoiding parameterization of the relevant scales. In a recent publication we have shown that UP, while not without its own complexity trade-offs, can produce encouraging improvements in low cloud climatology in multi-month simulations of the present climate and is a promising target for exascale computing (Parishani et al. 2017). Here we show results of its low cloud feedback to warming in multi-year simulations for the first time. References: Parishani, H., M. S. Pritchard, C. S. Bretherton, M. C. Wyant, and M. Khairoutdinov (2017), Toward low-cloud-permitting cloud superparameterization with explicit boundary layer turbulence, J. Adv. Model. Earth Syst., 9, doi:10.1002/2017MS000968.

  13. Origin of marine planktonic cyanobacteria.

    Science.gov (United States)

    Sánchez-Baracaldo, Patricia

    2015-12-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stochastic character mapping analyses from 131 cyanobacteria genomes with the aim to unravel key evolutionary steps involved in the origin of marine planktonic cyanobacteria. While filamentous cell types evolved early on at around 2,600-2,300 Mya and likely dominated microbial mats in benthic environments for most of the Proterozoic (2,500-542 Mya), marine planktonic cyanobacteria evolved towards the end of the Proterozoic and early Phanerozoic. Crown groups of modern terrestrial and/or benthic coastal cyanobacteria appeared during the late Paleoproterozoic to early Mesoproterozoic. Decrease in cell diameter and loss of filamentous forms contributed to the evolution of unicellular planktonic lineages during the middle of the Mesoproterozoic (1,600-1,000 Mya) in freshwater environments. This study shows that marine planktonic cyanobacteria evolved from benthic marine and some diverged from freshwater ancestors during the Neoproterozoic (1,000-542 Mya).

  14. Studies on marine oil spills and their ecological damage

    Science.gov (United States)

    Mei, Hong; Yin, Yanjie

    2009-09-01

    The sources of marine oil spills are mainly from accidents of marine oil tankers or freighters, marine oil-drilling platforms, marine oil pipelines, marine oilfields, terrestrial pollution, oil-bearing atmosphere, and offshore oil production equipment. It is concluded upon analysis that there are two main reasons for marine oil spills: (I) The motive for huge economic benefits of oil industry owners and oil shipping agents far surpasses their sense of ecological risks. (II) Marine ecological safety has not become the main concern of national security. Oil spills are disasters because humans spare no efforts to get economic benefits from oil. The present paper draws another conclusion that marine ecological damage caused by oil spills can be roughly divided into two categories: damage to marine resource value (direct value) and damage to marine ecosystem service value (indirect value). Marine oil spills cause damage to marine biological, fishery, seawater, tourism and mineral resources to various extents, which contributes to the lower quality and value of marine resources.

  15. Metabolism of polychlorinated biphenyls by marine bacteria

    International Nuclear Information System (INIS)

    Carey, A.E.; Harvey, G.R.

    1978-01-01

    There have been no reports of laboratory studies of PCB metabolism by marine organisms. A few workers have analyzed marine animals for products of PCB metabolism. A search for hydroxylated PCBs in marine fish proved inconclusive. Phenolic metabolites of PCBs have been identified in seals and guillemot. PCBs that had been hydroxylated and excreted by marine organisms would most likely be found in the sediments, so in our laboratory we conducted a search for these compounds in marine sediments. Two kilograms of organic-rich surface sediment from Buzzards Bay, Massachusetts, were extracted. The phenolic fraction was isolated and analyzed by gas chromatography-mass spectrometry (GC-MS). Neither wide mass scans nor selected mass searches produced any evidence of hydroxylated PCB derivatives. It was felt that if any marine organisms were capable of metabolism of PCBs, some marine bacteria should have that capability. Thus a series of laboratory experiments was conducted to test this possibility. Reported here is the finding of PCB metabolism by marine bacteria in batch culture

  16. Tissue specific haemoglobin gene expression suggests adaptation to local marine conditions in North Sea flounder (Platichthys flesus L.)

    DEFF Research Database (Denmark)

    Larsen, P.F.; Eg Nielsen, Einar; Hansen, M.M.

    2013-01-01

    Recent genetic analyses of candidate genes and gene expression in marine fishes have provided evidence of local adaptation in response to environmental differences, despite the lack of strong signals of population structure from conventional neutral genetic markers. In this study expression...... in flounder. In gill tissue a plastic response to salinity treatments was observed with general up-regulation of these genes concomitant with higher salinity. For liver tissue a population specific expression differences was observed with lower expression at simulated non-native compared to native salinities...... in high gene flow marine fishes. © 2013 The Genetics Society of Korea...

  17. Reducing the uncertainty in background marine aerosol radiative properties using CAM5 model results and CALIPSO-retrievals

    Science.gov (United States)

    Meskhidze, N.; Gantt, B.; Dawson, K.; Johnson, M. S.; Gasso, S.

    2012-12-01

    Abundance of natural aerosols in the atmosphere strongly affects global aerosol optical depth (AOD) and influences clouds and the hydrological cycle through its ability to act as cloud condensation nuclei (CCN). Because the anthropogenic contribution to climate forcing represents the difference between the total forcing and that from natural aerosols, understanding background aerosols is necessary to evaluate the influences of anthropogenic aerosols on cloud reflectivity and persistence (so-called indirect radiative forcing). The effects of marine aerosols are explored using remotely sensed data obtained by Cloud-aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and the NCAR Community Atmosphere Model (CAM5.0), coupled with the PNNL Modal Aerosol Model. CALIPSO-provided high resolution vertical profile information about different aerosol subtypes (defined as clean continental, marine, desert dust, polluted continental, polluted dust, and biomass burning), particulate depolarization ratio (or particle non-sphericity), reported aerosol color ratio (the ratio of aerosol backscatter at the two wavelengths) and lidar ratios over different parts of the oceans are compared to model-simulations to help evaluate the contribution of biogenic aerosol to CCN budget in the marine boundary layer. Model-simulations show that over biologically productive ocean waters primary organic aerosols of marine origin can contribute up to a 20% increase in CCN (at a supersaturation of 0.2%) number concentrations. Corresponding changes associated with cloud properties (liquid water path and droplet number) can decrease global annual mean indirect radiative forcing of anthropogenic aerosol (less cooling) by ~0.1 Wm-2 (7%). This study suggests ignoring the complex chemical composition and size distribution of sea spray particles could result in considerable uncertainties in predicted anthropogenic aerosol indirect effect.

  18. Assimilation of the Observational Data in the Marine Ecosystem Adaptive Model at the Known Mean Values of the Processes in the Marine Environment

    Directory of Open Access Journals (Sweden)

    I.Е. Тimchenko

    2017-10-01

    Full Text Available Assimilation of observational data in the marine ecosystem adaptive models constructed by the adaptive balance of causes method is considered. It is shown that the feedback balance between the ecosystem variables and the rates of their change used in the method equations, permits to introduce a stationary state of the ecosystem characterized by the observed mean values of the variables. The method for assessing the normalized coefficients of influences based on application of the Euler theorem on homogeneous functions to the functions representing material balances of biochemical reactions of the substance transformation is proposed. It is shown that the normalized ratios of the modeled process mean values can be used as the estimates of the reaction product derivatives obtained on the basis of their resources included in the equations of material balances. One-dimensional adaptive model of the sea upper layer ecosystem is constructed as an example; it is based on the scheme of cause-effect relations of the Fasham, Dacklow and McKelvie model of plankton dynamics and nitrogen cycle It is shown that in such a model, observational data is assimilated by automatic adaptation of the model variables to the assimilated information providing that the substance material balance are preserved in the transformation reactions. The data simulating both observations of the chlorophyll a concentrations and the marine environment dynamics are assimilated in the model. Time scenarios of the biochemical processes are constructed; they confirm applicability of the proposed method for assessing the effect coefficients based on the ratios of the simulated process mean values.

  19. Marine Ecological Environment Management Based on Ecological Compensation Mechanisms

    Directory of Open Access Journals (Sweden)

    Qunzhen Qu

    2016-12-01

    Full Text Available The level of marine environmental management is a key factor in the successful implementation of marine power strategies. The improvement in management levels of marine environments requires innovation in marine management. In other words, the transformation of marine environmental management into marine ecological environment management must be done in order to achieve sustainable development of the marine economy. As an environmental economic policy that combines both administrative and market measures, ecological compensation mechanisms have significant advantages in marine ecological environment management. Based on the study of the current development of ecological compensation mechanisms in China, through the analysis of the connotation of marine ecological civilization, existing marine ecological protection practices and marine environmental management methods, this paper posits that the current marine ecological environment management in China should be established on the basis of ecological compensation mechanisms. At present, a lack of laws and regulations for overall marine ecological environment management is the key factor restricting the practice of marine ecological environment management. Therefore, it is necessary to explore the current path of marine ecological environment management in China from the perspective of the construction of legal system of ecological compensation law, the establishment of ecological compensation fees, ecological taxes and ecological compensation fund systems, and the clear status for a marine ecological management and supervision body.

  20. The Source Book of Marine Sciences.

    Science.gov (United States)

    Beakley, John C.; And Others

    Included is a teachers resource collection of 42 marine science activities for high school students. Both the biological and the physical factors of the marine environment are investigated, including the study of tides, local currents, microscope measuring, beaches, turbidity, sea water solids, pH, and salinity, marine bacteriology, microbiology,…

  1. Recent Findings Based on Airborne Measurements at the Interface of Coastal California Clouds and Clear Air

    Science.gov (United States)

    Sorooshian, A.; Crosbie, E.; Wang, Z.; Chuang, P. Y.; Craven, J. S.; Coggon, M. M.; Brunke, M.; Zeng, X.; Jonsson, H.; Woods, R. K.; Flagan, R. C.; Seinfeld, J.

    2015-12-01

    Recent aircraft field experiments with the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter have targeted interfaces between clear and cloudy areas along the California coast. These campaigns, based out of Marina, California in the July-August time frame, include the Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE, 2011), Nucleation in California Experiment (NiCE, 2013), and the Biological Ocean Atmospheric Study (BOAS, 2015). Results will be presented related to (i) aqueous processing of natural and anthropogenic emissions, (ii) vertical re-distribution of ocean micronutrients, and (iii) stratocumulus cloud clearings and notable thermodynamic and aerosol contrasts across the clear-cloudy interface. The results have implications for modeling and observational studies of marine boundary layer clouds, especially in relation to aerosol-cloud interactions.

  2. Analysis of tethered balloon, ceilometer and class sounding data taken on San Nicolas Island during the FIRE project

    Science.gov (United States)

    Schubert, Wayne H.; Ciesielski, Paul E.; Guinn, Thomas A.; Cox, Stephen K.; Mckee, Thomas B.

    1990-01-01

    During the FIRE Marine Stratocumulus Program on San Nicolas Island, Colorado State University (CSU) and the British Meteorological Office (BMO) operated separate instrument packages on the NASA tethered balloon. The CSU package contained instrumentation for the measurement of temperature, pressure, humidity, cloud droplet concentration, and long and short wave radiation. Eight research flights, performed between July 7 and July 14, are summarized. An analysis priority to the July 7, 8 and 11 flights was assigned for the purposes of comparing the CSU and BMO data. Results are presented. In addition, CSU operated a laser ceilometer for the determination of cloud base, and a CLASS radiosonde site which launched 69 sondes. Data from all of the above systems are being analyzed.

  3. Transboundary radioactive and chemical pollution simulation using an atmospheric/marine predicting system

    International Nuclear Information System (INIS)

    Telenta, B.; Antic, D.

    2001-01-01

    The atmospheric models can be used to simulate the transport of contaminants in typical accidental cases and for realistic meteorological conditions. Some numerical models for weather forecast can be used for near to real simulations of propagation of radioactive nuclides or classical chemical pollutants to the atmosphere. The various meteorological parameters are taken into account and various meteorological conditions, even complex ones, can be analyzed. The models can be used for very well assessment of the airborne pollution from energy sources and industrial installations, for comparative studies and for safety analysis. This report describes an proposal for a project of the transboundary pollution simulation, that can be used for the East Mediterranean Region. The project is based on the numerical models developed in the in simulating of the Chernobyl accident and similar hypothetical cases. The study is based on an atmospheric models developed in Euro-Mediterranean Centre on Insular Coastal Dynamics (ICoD), Foundation for International Studies, Valeta, Malta

  4. Status and strategies for marine biodiversity of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.

    The status of marine biodiversity and factors responsible for the degradation and loss of marine biodiversity are discussed. Goa has abundant marine wealth. Phytoplankton, marine algae, manglicolous fungi, seagrasses, mangrove flora and other...

  5. Viruses manipulate the marine environment.

    Science.gov (United States)

    Rohwer, Forest; Thurber, Rebecca Vega

    2009-05-14

    Marine viruses affect Bacteria, Archaea and eukaryotic organisms and are major components of the marine food web. Most studies have focused on their role as predators and parasites, but many of the interactions between marine viruses and their hosts are much more complicated. A series of recent studies has shown that viruses have the ability to manipulate the life histories and evolution of their hosts in remarkable ways, challenging our understanding of this almost invisible world.

  6. Biodiversity conservation should focus on no-take Marine Reserves: 94% of Marine Protected Areas allow fishing.

    Science.gov (United States)

    Costello, Mark J; Ballantine, Bill

    2015-09-01

    Conservation needs places where nature is left wild; but only a quarter of coastal countries have no-take Marine Reserves. 'Marine Protected Areas' (MPAs) have been used to indicate conservation progress but we found that 94% allow fishing and thus cannot protect all aspects of biodiversity. Biodiversity conservation should focus on Marine Reserves, not MPAs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. The Smithsonian-led Marine Global Earth Observatory (MarineGEO): Proposed Model for a Collaborative Network Linking Marine Biodiversity to Ecosystem Processes

    Science.gov (United States)

    Duffy, J. E.

    2016-02-01

    Biodiversity - the variety of functional types of organisms - is the engine of marine ecosystem processes, including productivity, nutrient cycling, and carbon sequestration. Biodiversity remains a black box in much of ocean science, despite wide recognition that effectively managing human interactions with marine ecosystems requires understanding both structure and functional consequences of biodiversity. Moreover, the inherent complexity of biological systems puts a premium on data-rich, comparative approaches, which are best met via collaborative networks. The Smithsonian Institution's MarineGEO program links a growing network of partners conducting parallel, comparative research to understand change in marine biodiversity and ecosystems, natural and anthropogenic drivers of that change, and the ecological processes mediating it. The focus is on nearshore, seabed-associated systems where biodiversity and human population are concentrated and interact most, yet which fall through the cracks of existing ocean observing programs. MarineGEO offers a standardized toolbox of research modules that efficiently capture key elements of biological diversity and its importance in ecological processes across a range of habitats. The toolbox integrates high-tech (DNA-based, imaging) and low-tech protocols (diver surveys, rapid assays of consumer activity) adaptable to differing institutional capacity and resources. The model for long-term sustainability involves leveraging in-kind support among partners, adoption of best practices wherever possible, engagement of students and citizen scientists, and benefits of training, networking, and global relevance as incentives for participation. Here I highlight several MarineGEO comparative research projects demonstrating the value of standardized, scalable assays and parallel experiments for measuring fish and invertebrate diversity, recruitment, benthic herbivory and generalist predation, decomposition, and carbon sequestration. Key

  8. Lunge feeding in early marine reptiles and fast evolution of marine tetrapod feeding guilds.

    Science.gov (United States)

    Motani, Ryosuke; Chen, Xiao-hong; Jiang, Da-yong; Cheng, Long; Tintori, Andrea; Rieppel, Olivier

    2015-03-10

    Traditional wisdom holds that biotic recovery from the end-Permian extinction was slow and gradual, and was not complete until the Middle Triassic. Here, we report that the evolution of marine predator feeding guilds, and their trophic structure, proceeded faster. Marine reptile lineages with unique feeding adaptations emerged during the Early Triassic (about 248 million years ago), including the enigmatic Hupehsuchus that possessed an unusually slender mandible. A new specimen of this genus reveals a well-preserved palate and mandible, which suggest that it was a rare lunge feeder as also occurs in rorqual whales and pelicans. The diversity of feeding strategies among Triassic marine tetrapods reached their peak in the Early Triassic, soon after their first appearance in the fossil record. The diet of these early marine tetrapods most likely included soft-bodied animals that are not preserved as fossils. Early marine tetrapods most likely introduced a new trophic mechanism to redistribute nutrients to the top 10 m of the sea, where the primary productivity is highest. Therefore, a simple recovery to a Permian-like trophic structure does not explain the biotic changes seen after the Early Triassic.

  9. Transfer parameters of radionuclides in the marine environment

    International Nuclear Information System (INIS)

    1996-03-01

    To increase the accuracy of estimation of exposure dose by radionuclides in the marine, the informations of environmental parameter data in the marine were collected, arranged and discussed. The informations were discussed by 'a sectional committee of marine suspended solids and sediment'. The following problems were investigated and the studies were recorded in this report, clear explanation about the distribution factor (kd), the estimation method of kd, the fluctuating factor of kd data (properties of suspension and sediment, differences among the experimental methods), the physical and chemical behavior of radionuclides, sediment of radionuclides by means of sorption to the suspended particles in the marine, sorption of radionuclides into the marine soil (sediment), re-eluent of radionuclides sorpted in the marine soil (sediment), and relation between marine organism and marine suspended materials and sediment. (S.Y.)

  10. Sensitivity Analysis of Heavy Fuel Oil Spray and Combustion under Low-Speed Marine Engine-Like Conditions

    Directory of Open Access Journals (Sweden)

    Lei Zhou

    2017-08-01

    Full Text Available On account of their high power, thermal efficiency, good reliability, safety, and durability, low-speed two-stroke marine diesel engines are used as the main drive devices for large fuel and cargo ships. Most marine engines use heavy fuel oil (HFO as the primary fuel, however, the physical and chemical characteristics of HFO are not clear because of its complex thermophysical properties. The present study was conducted to investigate the effects of fuel properties on the spray and combustion characteristics under two-stroke marine engine-like conditions via a sensitivity analysis. The sensitivity analysis of fuel properties for non-reacting and reacting simulations are conducted by comparing two fuels having different physical properties, such as fuel density, dynamic viscosity, critical temperature, and surface tension. The performances of the fuels are comprehensively studied under different ambient pressures, ambient temperatures, fuel temperatures, and swirl flow conditions. From the results of non-reacting simulations of HFO and diesel fuel properties in a constant volume combustion chamber, it can be found that the increase of the ambient pressure promotes fuel evaporation, resulting in a reduction in the steady liquid penetration of both diesel and HFO; however, the difference in the vapor penetrations of HFO and diesel reduces. Increasing the swirl flow significantly influences the atomization of both HFO and diesel, especially the liquid distribution of diesel. It is also found that the ambient temperature and fuel temperature have the negative effects on Sauter mean diameter (SMD distribution. For low-speed marine engines, the combustion performance of HFO is not sensitive to activation energy in a certain range of activation energy. At higher engine speed, the difference in the effects of different activation energies on the in-cylinder pressure increases. The swirl flow in the cylinder can significantly promote fuel evaporation and

  11. Marine Peptides and Their Anti-Infective Activities

    OpenAIRE

    Kang, Hee Kyoung; Seo, Chang Ho; Park, Yoonkyung

    2015-01-01

    Marine bioresources are a valuable source of bioactive compounds with industrial and nutraceutical potential. Numerous clinical trials evaluating novel chemotherapeutic agents derived from marine sources have revealed novel mechanisms of action. Recently, marine-derived bioactive peptides have attracted attention owing to their numerous beneficial effects. Moreover, several studies have reported that marine peptides exhibit various anti-infective activities, such as antimicrobial, antifungal,...

  12. International laboratory of marine radioactivity

    International Nuclear Information System (INIS)

    1981-08-01

    The director's report presents the overall aims and objectives of the laboratory, and some of the significant findings to date. Among these is the different behaviour in oceans of Pu and Am. Thus, fallout Pu, in contrast to Am, tends to remain in the soluble form. The vertical downward transport of Am is much quicker than for Pu. Since 1980, uptake and depuration studies of sup(95m)Tc have been carried out on key marine species. Marine environmental behaviour of Tc is being evaluated carefully in view of its being a significant constituent of nuclear wastes. Growing demands are being made on the laboratory for providing intercalibration and instrument maintenance services, and for providing training for scientists from developing countries. The body of the report is divided into 5 sections dealing with marine biology, marine chemistry, marine geochemistry/sedimentation, environmental studies, and engineering services, respectively. Appendices list laboratory staff, publications by staff members, papers and reports presented at meetings or conferences, consultants to the laboratory from 1967-1980, fellowships, trainees and membership of committees, task forces and working groups

  13. Marine microorganisms. Umi no biseibutsu

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, U. (Hiroshima University, Hiroshima (Japan). Faculty of Applied Biological Science)

    1992-11-10

    This paper explains properties, interactions, and activities of marine microorganisms. Marine bacteria include bacteria of vibrio family of arteromonas genus, luminous bacteria, and aerobic photosynthetic bacteria. Majority of marine bacteria is halophilic, and many proliferate at 5[degree]C or lower. Some of them can proliferate at 20[degree]C to 30[degree]C, or as high temperature as 80[degree]C and higher. Spongiaria and tumicata have many symbiotic microorganisms, and genes equivalent to luminous bacteria genes were discovered in DNA of light emitting organs in luminous fishes. It was verified that animal groups in upwelling zones are supported by bacteria that assimilate inorganics supplied from ocean bottoms. Marine bacteria decompose almost all of organics brought in from land to sea, and those produced in sea. Marine bacteria engage in complex interrelations with other organisms for competition, antagonism, parasitism, and symbiosis. The bacteria make antibacterial substances, anti-algae bacteria, enzyme inhibitors, toxins, pharmacologically active substances, and such physiologically active substances as deposition promoting substances to undersea structures including shells and barnacles, and deposition blocking substances. 53 refs., 3 figs.

  14. Nonlinear acoustics of water-saturated marine sediments

    DEFF Research Database (Denmark)

    Jensen, Leif Bjørnø

    1976-01-01

    Interest in the acoustic qualities of water-saturated marine sediments has increased considerably during recent years. The use of sources of high-intensity sound in oil propsecting, in geophysical and geological studies of bottom and subbottom materials and profiles and recently in marine...... archaeology has emphasized the need of information about the nonlinear acoustic qualities of water-saturated marine sediments. While the acoustic experiments and theoretical investigations hitherto performed have concentrated on a determination of the linear acoustic qualities of water-saturated marine...... sediments, their parameters of nonlinear acoustics are still unexplored. The strong absorption, increasing about linearly with frequency, found in most marine sediments and the occurrence of velocity dispersion by some marine sediments restrict the number of nonlinear acoustic test methods traditionally...

  15. The Danish Marine Monitoring System

    DEFF Research Database (Denmark)

    Ærtebjerg, G.

    1997-01-01

    Indeholder abstracts fra Workshop on Marine Monitoring Systems and Technology, Risø, 17-18 April 1996.......Indeholder abstracts fra Workshop on Marine Monitoring Systems and Technology, Risø, 17-18 April 1996....

  16. 77 FR 42279 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a...

    Science.gov (United States)

    2012-07-18

    ... the shutdown zone clear of marine mammals; animals will be allowed to remain in the shutdown zone (i.e... these problems, any adverse responses to construction activities by marine mammals, and a complete... of impacts of sound on marine mammals, it is common practice to estimate how many animals are likely...

  17. Proceedings of the 2008 marine biodiesel symposium

    International Nuclear Information System (INIS)

    2008-01-01

    In addition to producing lower hydrocarbon emissions, marine biodiesel is biodegradable and does not harm fish. This symposium was held to discuss current marine biodiesel applications and examine methods of increasing the use of biodiesel in marine environments in British Columbia (BC). Biofuel policies and mandates in the province were reviewed, and methods of expanding the biodiesel market were explored. Updates on the use of biodiesel in ferries, tugboats, and smaller marine diesel engine applications were provided. Biodiesel projects in the United States were discussed. The environmental impacts of marine biodiesel were evaluated, and federal policies and standards for biodiesel were also outlined. The symposium was divided into the following 5 main sessions: (1) policy, (2) overviews, (3) using biodiesel in marine engines, (4) biodiesel in larger marine vessels, and (5) biodiesel quality and environmental considerations. The conference featured 13 presentations, of which 4 have been catalogued separately for inclusion in this database. tabs., figs

  18. Food enrichment with marine phospholipid emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    marine PL emulsions with and without addition of fish oil. The oxidative stability of marine PL emulsions was significantly influenced by the chemical composition of marine PL used for emulsions preparation. For instance, emulsions with good oxidative stability could be obtained when using raw materials...... with high purity, low fish oil content and high PL, cholesterol and α-tocopherol content. In addition, non-enzymatic browning reactions may also affect the oxidative stability of the marine PL emulsion. These reactions included Strecker degradation and pyrrolization, and their occurrence were due......Many studies have shown that marine phospholipids (PL) provide more advantages than fish oil. They seem to have better bioavailability, better resistance towards oxidation and higher content of eicosapentaenoic acids and docosahexaenoic acids than fish oil, which essentially contains triglycerides...

  19. Cumulative human impacts on marine predators.

    Science.gov (United States)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J; Halpern, Benjamin S; Breed, Greg A; Nickel, Barry; Teutschel, Nicole M; Crowder, Larry B; Benson, Scott; Dutton, Peter H; Bailey, Helen; Kappes, Michelle A; Kuhn, Carey E; Weise, Michael J; Mate, Bruce; Shaffer, Scott A; Hassrick, Jason L; Henry, Robert W; Irvine, Ladd; McDonald, Birgitte I; Robinson, Patrick W; Block, Barbara A; Costa, Daniel P

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact (CUI) on marine predators by combining electronic tracking data of eight protected predator species (n=685 individuals) in the California Current Ecosystem with data on 24 anthropogenic stressors. We show significant variation in CUI with some of the highest impacts within US National Marine Sanctuaries. High variation in underlying species and cumulative impact distributions means that neither alone is sufficient for effective spatial management. Instead, comprehensive management approaches accounting for both cumulative human impacts and trade-offs among multiple stressors must be applied in planning the use of marine resources.

  20. Production of Enzymes from Marine Actinobacteria.

    Science.gov (United States)

    Zhao, X Q; Xu, X N; Chen, L Y

    Marine actinobacteria are well recognized for their capabilities to produce valuable natural products, which have great potential for applications in medical, agricultural, and fine chemical industries. In addition to producing unique enzymes responsible for biosynthesis of natural products, many marine actinobacteria also produce hydrolytic enzymes which are able to degrade various biopolymers, such as cellulose, xylan, and chitin. These enzymes are important to produce biofuels and biochemicals of interest from renewable biomass. In this chapter, the recent reports of novel enzymes produced by marine actinobacteria are reviewed, and advanced technologies that can be applied to search for novel marine enzymes as well as for improved enzyme production by marine actinobacteria are summarized, which include ribosome engineering, genome mining, as well as synthetic biology studies. © 2016 Elsevier Inc. All rights reserved.

  1. Investigating the Marine Environment and Its Resources, Part II.

    Science.gov (United States)

    Lien, Violetta F.

    This is the second of two volumes comprising a resource unit designed to help students become more knowledgeable about the marine environment and its resources. Included in this volume are discussions of changes in the human and marine environment, human needs, marine resources, living marine resources, marine transportation, marine energy…

  2. Multiscale Methods for Accurate, Efficient, and Scale-Aware Models

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Vincent [Univ. of Wisconsin, Milwaukee, WI (United States)

    2017-07-14

    The goal of UWM’s portion of the Multiscale project was to develop a unified cloud parameterization that could simulate all cloud types --- including stratocumulus, shallow cumulus, and deep cumulus --- using the single equation set implemented in CLUBB. An advantage of a unified parameterization methodology is that it avoids the difficult task of interfacing different cloud parameterizations for different cloud types. To interface CLUBB’s clouds to the microphysics, a Monte Carlo interface, SILHS, was further developed.

  3. Does terrestrial epidemiology apply to marine systems?

    Science.gov (United States)

    McCallum, Hamish I.; Kuris, Armand M.; Harvell, C. Drew; Lafferty, Kevin D.; Smith, Garriet W.; Porter, James

    2004-01-01

    Most of epidemiological theory has been developed for terrestrial systems, but the significance of disease in the ocean is now being recognized. However, the extent to which terrestrial epidemiology can be directly transferred to marine systems is uncertain. Many broad types of disease-causing organism occur both on land and in the sea, and it is clear that some emergent disease problems in marine environments are caused by pathogens moving from terrestrial to marine systems. However, marine systems are qualitatively different from terrestrial environments, and these differences affect the application of modelling and management approaches that have been developed for terrestrial systems. Phyla and body plans are more diverse in marine environments and marine organisms have different life histories and probably different disease transmission modes than many of their terrestrial counterparts. Marine populations are typically more open than terrestrial ones, with the potential for long-distance dispersal of larvae. Potentially, this might enable unusually rapid propagation of epidemics in marine systems, and there are several examples of this. Taken together, these differences will require the development of new approaches to modelling and control of infectious disease in the ocean.

  4. Climate change and marine top predators

    DEFF Research Database (Denmark)

    Climate change affects all components of marine ecosystems. For endothermic top predators, i.e. seabirds and marine mammals, these impacts are often complex and mediated through trophic relationships. In this Research Topic, leading researchers attempt to identify patterns of change among seabirds...... and marine mammals, and the mechanisms through which climate change drives these changes....

  5. Marine Anthropogenic Litter

    OpenAIRE

    Bergmann, Melanie; Gutow, Lars; Klages, Michael

    2015-01-01

    This book describes how manmade litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers co...

  6. Radioactive monitoring of the marine environment

    International Nuclear Information System (INIS)

    Bologa, A. S.

    1991-01-01

    Radioactivity monitoring of marine environment was required by the development of nuclear power and the worldwide use of ionizing radiations in many different activities. Both natural and artificial radioactivity play an important role in marine ecology and human health. In respect of this, three major facts prevail, namely: the fallout, the proximity of Danube River and the future nuclear power production. Spatial and temporal monitoring of marine radioactivity along the Romanian Black Sea shore has been systematically performed in Romanian Marine Research Institute in close cooperation with Institute of Meteorology and Hydrology since 1981. Marine emerged and submerged sediments, coastal and offshore sea water, macroalgae, invertebrates and fish of Danube mouths and/or along the coast are monitored for natural and artificial radioactivity by means of gross beta measurements and gamma spectrometry. Concentrations of radionuclides such as: K-40, Cs-134 and Cs-137 in abiotic and biotic samples, environmental distribution coefficients and concentration factors (CFs) as well as experimentally derived CFs in marine biota as radioecological bioindicators are assessed and stored in a national data base. (author)

  7. A Fortran-77 program for Monte Carlo simulation of upwelling light from the sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sathe, P.V.; Sathyendranath, S.

    for Monte Carlo simulation of spectral and angular composition of upwelling light emerging from a wind-roughened sea under given physical conditions and for a given water quality. The program also simulates the light field prevailing immediately below... constituents of the sea which influence the quality of upwelling light. Because the program is a direct simulation of radiative transfer from the atmosphere to the sea and vice versa, it may be put to a variety of uses in studies in marine optics. Simulated...

  8. Exploring the role of movement in determining the global distribution of marine biomass using a coupled hydrodynamic - Size-based ecosystem model

    Science.gov (United States)

    Watson, James R.; Stock, Charles A.; Sarmiento, Jorge L.

    2015-11-01

    Modeling the dynamics of marine populations at a global scale - from phytoplankton to fish - is necessary if we are to quantify how climate change and other broad-scale anthropogenic actions affect the supply of marine-based food. Here, we estimate the abundance and distribution of fish biomass using a simple size-based food web model coupled to simulations of global ocean physics and biogeochemistry. We focus on the spatial distribution of biomass, identifying highly productive regions - shelf seas, western boundary currents and major upwelling zones. In the absence of fishing, we estimate the total ocean fish biomass to be ∼ 2.84 ×109 tonnes, similar to previous estimates. However, this value is sensitive to the choice of parameters, and further, allowing fish to move had a profound impact on the spatial distribution of fish biomass and the structure of marine communities. In particular, when movement is implemented the viable range of large predators is greatly increased, and stunted biomass spectra characterizing large ocean regions in simulations without movement, are replaced with expanded spectra that include large predators. These results highlight the importance of considering movement in global-scale ecological models.

  9. Marine Corps Amphibious Combat Vehicle (ACV) and Marine Personnel Carrier (MPC): Background and Issues for Congress

    Science.gov (United States)

    2016-09-09

    providing critical capabilities to execute the nation’s military strategy . On January 6, 2011, after spending approximately $3 billion in...the Landing Craft , Air Cushioned (LCAC). The LAV-25 has been in service since 1983. According to the Marine Program Executive Office (PEO) Land...the Marines’ new MPC/ACV acquisition strategy and its associated challenges and risks. Marine Corps Amphibious Combat Vehicle (ACV) and Marine

  10. Antifouling Compounds from Marine Invertebrates

    OpenAIRE

    Qi, Shu-Hua; Ma, Xuan

    2017-01-01

    In this review, a comprehensive overview about the antifouling compounds from marine invertebrates is described. In total, more than 198 antifouling compounds have been obtained from marine invertebrates, specifically, sponges, gorgonian and soft corals.

  11. Antifouling Compounds from Marine Invertebrates.

    Science.gov (United States)

    Qi, Shu-Hua; Ma, Xuan

    2017-08-28

    In this review, a comprehensive overview about the antifouling compounds from marine invertebrates is described. In total, more than 198 antifouling compounds have been obtained from marine invertebrates, specifically, sponges, gorgonian and soft corals.

  12. Radiochemical tracers in marine biology

    International Nuclear Information System (INIS)

    Petrocelli, S.R.; Anderson, J.W.; Neff, J.M.

    1977-01-01

    Tracers have been used in a great variety of experimentation. More recently, labeled materials have been applied in marine biological research. Some of the existing tracer techniques have been utilized directly, while others have been modified to suit the specific needs of marine biologists. This chapter describes some of the uses of tracers in marine biological research. It also mentions the problems encountered as well as offering possible solutions and discusses further applications of these techniques. Only pertinent references are cited and additional information may be obtained by consulting these references. Due to their relative ease of maintenance, freshwater species are also utilized in studies which involve radiotracer techniques. Since most of these techniques e directly applicable to marine species, some of these studies will also be included

  13. 8. Danish meeting for marine researchers

    International Nuclear Information System (INIS)

    1994-01-01

    The publication comprises the programme for the 8th Danish meeting for marine researchers held in Odense (Denmark) on January 25th - 27th, 1994, and the abstracts of the papers that were presented at that meeting. Subjects covered are marine biology, sediments and sedimentation, fish, fishing and fishing regulation, marine processes and the monitoring of Danish straits. (AB)

  14. The 10. Danish marine research meeting

    International Nuclear Information System (INIS)

    1998-01-01

    The publication comprises the programme for the 10th Danish meeting for marine researchers held in Hirtshals (Denmark) on January 21 - 27, 1998, and the abstracts of the papers that were presented at that meeting. Subjects covered are marine biology, sediments and sedimentation, fish, fishing and fishing regulations, marine processes and the monitoring of Danish straits. (EG)

  15. Decomposition of 14C-labeled organic substances in marine sediments

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The depth variation of total organic carbon (TOC), organic matter composition and porewater composition in marine sediments suggest that different components of the organic matter undergo decomposition at widely different rates. The decomposition of 14 C-labeled organic substances was followed in sediment microcosms in the laboratory. The substances used were chosen to simulate a portion of material settling to the sediment-water interface (a marine diatom) or hypothesized components of refractory sediment organic matter (melanoidins and a bacterial polymer). The microcosms were found to be good models of the sediment-water interface in terms of how well they mimicked sediment decomposition rates and processes. The decomposition of the labeled material and the natural sediment TOC were monitored over 1 month: the water overlying the sediment remained oxic, and net consumption of nitrate was small. There was no detectable sulfate reduction. The algae and the bacterial polymer were decomposed on average 9x faster than the melanoidins and 90x faster than the natural sediment TOC. The soluble fraction of the algae was decomposed more rapidly than the particulate material

  16. Stochastic dynamic analysis of marine risers considering Gaussian system uncertainties

    Science.gov (United States)

    Ni, Pinghe; Li, Jun; Hao, Hong; Xia, Yong

    2018-03-01

    This paper performs the stochastic dynamic response analysis of marine risers with material uncertainties, i.e. in the mass density and elastic modulus, by using Stochastic Finite Element Method (SFEM) and model reduction technique. These uncertainties are assumed having Gaussian distributions. The random mass density and elastic modulus are represented by using the Karhunen-Loève (KL) expansion. The Polynomial Chaos (PC) expansion is adopted to represent the vibration response because the covariance of the output is unknown. Model reduction based on the Iterated Improved Reduced System (IIRS) technique is applied to eliminate the PC coefficients of the slave degrees of freedom to reduce the dimension of the stochastic system. Monte Carlo Simulation (MCS) is conducted to obtain the reference response statistics. Two numerical examples are studied in this paper. The response statistics from the proposed approach are compared with those from MCS. It is noted that the computational time is significantly reduced while the accuracy is kept. The results demonstrate the efficiency of the proposed approach for stochastic dynamic response analysis of marine risers.

  17. Characterization of elements in marine organisms

    International Nuclear Information System (INIS)

    Ishii, Toshiaki

    1993-01-01

    Characterization of elements in marine organisms was carried out to estimate the behavior of radionuclides in marine ecosystem or to clarify the physiological roles of elements in marine organisms. The concentrations of 238 U in fifty-five species of marine organisms were measured by inductively coupled plasma mass spectrometry. The concentrations of 238 U in soft tissues of marine animals ranged from 0.076 to 5000ng/g wet wt. Especially, the branchial heart of octopus vulgaris showed the specific accumulation of 238 U. The kidney granules of bivalve molluscs showed very high concentrations of Mn, Zn, 210 Pb, 210 Po etc. The XAFS study for the granules of Cyclosunetta menstrualis indicated that the chemical form of metals in the granules was phosphate (e. g. Mn 3 (PO 4 ) 2 · 4H 2 O). (author)

  18. Bioactivity of marine organisms. Part 5. Screening of some marine fauna from the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, C.G.; Kamat, S.Y.; Parameswaran, P.S.; Das, B.; Patel, J.; Ramani, P.; Bhakuni, D.S.; Goel, A.K.; Jain, S.; Srimal, R.C.

    (December), 1990, pp. 153-157 BIOACTIVITY OF MARINE ORGANISMS PART V : SCREENING OF SOME MARINE FAUNA FROM THE INDIAN COAST , CG. NAIK, S.Y. KAMAT, P.S. PARAMESHWARAN, B. DAS, JIVEXA PATEL, PRITA RAMANI, D.S. BHAKUNI", A.K. GOEL", SUDHA JAIN" AND R.c. SRIMAL... of Oceanography, Goa, in collaboration with the Central Drug Research Institute, Lucknow for the screening of extracts ofmarine organisms for a wide range of biological activities. The programme consists of collection, identification and extraction of marine flora...

  19. Marine Protected Dramas: The Flaws of the Brazilian National System of Marine Protected Areas

    Science.gov (United States)

    Gerhardinger, Leopoldo C.; Godoy, Eduardo A. S.; Jones, Peter J. S.; Sales, Gilberto; Ferreira, Beatrice P.

    2011-04-01

    This article discusses the current problems and issues associated with the implementation of a National System of Marine Protected Areas in Brazil. MPA managers and higher governmental level authorities were interviewed about their perceptions of the implementation of a national MPA strategy and the recent changes in the institutional arrangement of government marine conservation agencies. Interviewees' narratives were generally pessimistic and the National System was perceived as weak, with few recognizable marine conservation outcomes on the ground. The following major flaws were identified: poor inter-institutional coordination of coastal and ocean governance; institutional crisis faced by the national government marine conservation agency; poor management within individual MPAs; problems with regional networks of marine protected areas; an overly bureaucratic management and administrative system; financial shortages creating structural problems and a disconnect between MPA policy and its delivery. Furthermore, a lack of professional motivation and a pessimistic atmosphere was encountered during many interviews, a malaise which we believe affects how the entire system is able to respond to crises. Our findings highlight the need for a better understanding of the role of `leadership' in the performance of socio-ecological systems (such as MPA networks), more effective official evaluation mechanisms, more localized audits of (and reforms if necessary to) Brazil's federal biodiversity conservation agency (ICMBio), and the need for political measures to promote state leadership and support. Continuing to focus on the designation of more MPAs whilst not fully addressing these issues will achieve little beyond fulfilling, on paper, Brazil's international marine biodiversity commitments.

  20. SANCOR: Summary report on marine research 1987

    CSIR Research Space (South Africa)

    SANCOR

    1988-01-01

    Full Text Available , Marine Linefish, Marine Pollution, Marine Sedimentology and the newly formed Ocean Engineering programme. This report includes brief statements on the activities of each of these programmes in 1987 and emphasizes important findings and conclusions...

  1. Preamble to marine microbiology: Facets and opportunities

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.

    The book titled 'Marine Microbiology: Facets & Opportunities' is an attempt to bring together some facets of marine microbiology as have been made out by many contemporaries in particular from the tropical marine regions. There are 18 contributed...

  2. Waste production and regional growth of marine activities an econometric model

    International Nuclear Information System (INIS)

    Bramati, Maria Caterina

    2016-01-01

    Coastal regions are characterized by intense human activity and climatic pressures, often intensified by competing interests in the use of marine waters. To assess the effect of public spending on the regional economy, an econometric model is here proposed. Not only are the regional investment and the climatic risks included in the model, but also variables related to the anthropogenic pressure, such as population, economic activities and waste production. Feedback effects of economic and demographic expansion on the pollution of coastal areas are also considered. It is found that dangerous waste increases with growing shipping and transportation activities and with growing population density in non-touristic coastal areas. On the other hand, the amount of non-dangerous wastes increases with marine mining, defense and offshore energy production activities. However, lower waste production occurs in areas where aquaculture and touristic industry are more exploited, and accompanied by increasing regional investment in waste disposal. - Highlights: • We use an econometric model as a tool for assessing the effects of regional policies on the development of economic activities related to the use of the sea and on the impact on the marine environment. • Through scenario simulation we provide strategic guidelines for policy makers and economic planners • The model features feedback effects of economic and demographic expansion on the pollution of coastal areas.

  3. 76 FR 28422 - Marine Mammals; File No. 16053

    Science.gov (United States)

    2011-05-17

    ... Paul E. Nachtigall, PhD, Marine Mammal Research Program Hawaii Institute of Marine Biology, P.O. Box... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA384 Marine Mammals; File No. 16053 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric...

  4. Towards Marine Spatial Planning in Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Meng-Tsung Lee

    2014-11-01

    Full Text Available Due to population growth, rapid economic development and inadequate marine control, the use of ocean and coastal regions in Taiwan has become more frequent and intense in recent years. However, the lack of comprehensive marine and coastal planning in this island nation has led to many conflicts over space and resources and limited its ability to prepare for and respond to environmental hazards, thus threatening national security as well as the safety and property of its citizens. This study proposes a marine zoning scheme for southern Taiwan. The results show that many important habitats in the southern sea areas have not been properly protected due to the extremely small size of the marine protected area. Furthermore, the majority of the conflicts derive from the exclusive fishing right vs. other uses such as marine conservation. Therefore, it is crucial to establish the marine spatial planning (MSP for the Southern Taiwan to deal with the conflicts of use seas and uncertainties associated with complex, heterogeneous, and dynamic marine system.

  5. Marine disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Woodhead, D.S.

    1980-01-01

    In a general sense, the main attraction of the marine environment as a repository for the wastes generated by human activities lies in the degree of dispersion and dilution which is readily attainable. However, the capacity of the oceans to receive wastes without unacceptable consequences is clearly finite and this is even more true of localized marine environments such as estuaries, coastal waters and semi-enclosed seas. Radionuclides have always been present in the marine environment and marine organisms and humans consuming marine foodstuffs have always been exposed, to some degree, to radiation from this source. The hazard associated with ionizing radiations is dependent upon the adsorption of energy from the radiation field within some biological entity. Thus any disposal of radioactive wastes into the marine environment has consequences, the acceptability of which must be assessed in terms of the possible resultant increase in radiation exposure of human and aquatic populations. In the United Kingdom the primary consideration has been and remains the safe-guarding of public health. The control procedures are therefore designed to minimize as far as practicable the degree of human exposure within the overall limits recommended as acceptable by the International Commission on Radiological Protection. There are several approaches through which control could be exercised and the strenghs and weaknesses of each are considered. In this review the detailed application of the critical path technique to the control of the discharge into the north-east Irish Sea from the fuel reprocessing plant at Windscale is given as a practical example. It will be further demonstrated that when human exposure is controlled in this way no significant risk attaches to the increased radiation exposure experienced by populations of marine organisms in the area. (orig.) [de

  6. Numerical Simulation of Methane Slip in Dual Fuel Marine Engines

    DEFF Research Database (Denmark)

    Han, Jaehyun; Jensen, Michael Vincent; Pang, Kar Mun

    2017-01-01

    estimations. The simulations with various gas pipe geometries were conducted. It seemed that the effect of the change in injection direction is more dominant than the change in the gas hole configuration. The favorable injection direction for minimum amount of methane slip was discovered as the direction...... which helps developing the flow of methane far from the exhaust ports. The effects of various valve timing settings were also simulated. The advancement of the exhaust valve closing was more efficient than the retardation of the intake valve opening. A little retardation of the intake valve opening even......The methane slip is the problematic issue for the engines using natural gas(NG). Because methane is more powerful greenhouse gas (GHG) than CO2, understanding of the methane slip during gas exchange process of the engines is essential. In this study, the influence of the gas pipe geometry...

  7. Marine natural flavonoids: chemistry and biological activities.

    Science.gov (United States)

    Martins, Beatriz T; Correia da Silva, Marta; Pinto, Madalena; Cidade, Honorina; Kijjoa, Anake

    2018-05-04

    As more than 70% of the world's surface is covered by oceans, marine organisms offer a rich and unlimited resource of structurally diverse bioactive compounds. These organisms have developed unique properties and bioactive compounds that are, in majority of them, unparalleled by their terrestrial counterparts due to the different surrounding ecological systems. Marine flavonoids have been extensively studied in the last decades due to a growing interest concerning their promising biological/pharmacological activities. The most common classes of marine flavonoids are flavones and flavonols, which are mostly isolated from marine plants. Although most of flavonoids are hydroxylated and methoxylated, some marine flavonoids possess an unusual substitution pattern, not commonly found in terrestrial organisms, namely the presence of sulphate, chlorine, and amino groups. This review presents, for the first time in a systematic way, the structure, natural occurrence, and biological activities of marine flavonoids.

  8. Analysis of a novel autonomous marine hybrid power generation/energy storage system with a high-voltage direct current link

    DEFF Research Database (Denmark)

    Wang, L.; Lee, D. J.; Lee, W. J.

    2008-01-01

    wind turbines andWells turbines to respectively capture wind energy and wave energy from marine wind and oceanwave. In addition to wind-turbine generators(WTGs) andwave-energy turbine generators (WETGs) employed in the studied system, diesel-engine generators (DEGs) and an aqua electrolyzer (AE......This paper presents both time-domain and frequency-domain simulated results of a novel marine hybrid renewable-energy power generation/energy storage system (PG/ESS) feeding isolated loads through an high-voltage direct current (HVDC) link. The studied marine PG subsystems comprise both offshore......) absorbing a part of generated energy from WTGs and WETGs to generate available hydrogen for fuel cells (FCs) are also included in the PG subsystems. The ES subsystems consist of a flywheel energy storage system(FESS) and a compressed air energy storage (CAES) system to balance the required energy...

  9. 76 FR 25308 - Marine Mammals

    Science.gov (United States)

    2011-05-04

    ...-XA165 Marine Mammals AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... Jennifer Burns, Ph.D., University of Alaska Anchorage, Biology Department, 3101 Science Circle, Anchorage, AK, has been issued a permit to conduct [[Page 25309

  10. Faunistics (marine animals)

    DEFF Research Database (Denmark)

    2009-01-01

    These PowerPoint files are compiled from various sources: Internet, field guides, scientific monographs, textbooks, my own photos and drawings, etc. I have no copyright or permission to use most of the illustrations. The file is therefore only intended for internal use within the Marine Biology...... for identification have only been included for about a quarter of the species only, because of lack of time).     These files contain information of about 570 species of marine invertebrates found in the waters around Denmark. They should be the most common species. Which species should be selected for files like......) with the programme PowerPoint X for Mac® Service Release 1.     Comments and suggestions are welcome from students and colleagues. HD&P = Køie, Kristiansen & Weitemeyer, Havets dyr og planter. DN = Danmarks Natur, vol. 3, Havet     Tomas Cedhagen, Department of Marine Ecology, University of Aarhus, Finlandsgade 14...

  11. 75 FR 12734 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Operation of Offshore...

    Science.gov (United States)

    2010-03-17

    ... marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including... supplies; production operations; drilling operations; pipeline design, inspection, and maintenance; routine...

  12. Marine oils: Complex, confusing, confounded?

    Directory of Open Access Journals (Sweden)

    Benjamin B. Albert

    2016-09-01

    Full Text Available Marine oils gained prominence following the report that Greenland Inuits who consumed a high-fat diet rich in long-chain n-3 polyunsaturated fatty acids (PUFAs also had low rates of cardiovascular disease. Marine n-3 PUFAs have since become a billion dollar industry, which will continue to grow based on current trends. However, recent systematic reviews question the health benefits of marine oil supplements, particularly in the prevention of cardiovascular disease. Marine oils constitute an extremely complex dietary intervention for a number of reasons: i the many chemical compounds they contain; ii the many biological processes affected by n-3 PUFAs; iii their tendency to deteriorate and form potentially toxic primary and secondary oxidation products; and iv inaccuracy in the labelling of consumer products. These complexities may confound the clinical literature, limiting the ability to make substantive conclusions for some key health outcomes. Thus, there is a pressing need for clinical trials using marine oils whose composition has been independently verified and demonstrated to be minimally oxidised. Without such data, it is premature to conclude that n-3 PUFA rich supplements are ineffective.

  13. Marine oil spill response organizations

    International Nuclear Information System (INIS)

    Hendry, C.

    1997-01-01

    The obligations under the law relative to the prevention of marine oil spills and the type of emergency plans needed to mitigate any adverse effects caused by a marine oil spill were discussed. The organizational structure, spill response resources and operational management capabilities of Canada's newly created Response Organizations (ROs) were described. The overall range of oil spill response services that the RO provides to the domestic oil handling, oil transportation and the international shipping industries were reviewed. Amendments to the Canada Shipping Act which require that certain ships and oil handling facilities take oil spill preparedness and response measures, including having an arrangement with an RO certified by the Canadian Coast Guard, were outlined. Canadians now benefit from five ROs established to provide coast-to-coast oil spill response coverage. These include the Western Canada Marine Response Corporation, the Canadian Marine Response Management Corporation, the Great Lakes Response Corporation, the Eastern Canada Response Corporation and the Atlantic Emergency Response Team Ltd. ROs have the expertise necessary to organize and manage marine oil spill response services. They can provide equipment, personnel and operational management for the containment, recovery and cleanup of oil spilled on water

  14. Marine Peptides: Bioactivities and Applications

    Directory of Open Access Journals (Sweden)

    Randy Chi Fai Cheung

    2015-06-01

    Full Text Available Peptides are important bioactive natural products which are present in many marine species. These marine peptides have high potential nutraceutical and medicinal values because of their broad spectra of bioactivities. Their antimicrobial, antiviral, antitumor, antioxidative, cardioprotective (antihypertensive, antiatherosclerotic and anticoagulant, immunomodulatory, analgesic, anxiolytic anti-diabetic, appetite suppressing and neuroprotective activities have attracted the attention of the pharmaceutical industry, which attempts to design them for use in the treatment or prevention of various diseases. Some marine peptides or their derivatives have high commercial values and had reached the pharmaceutical and nutraceutical markets. A large number of them are already in different phases of the clinical and preclinical pipeline. This review highlights the recent research in marine peptides and the trends and prospects for the future, with special emphasis on nutraceutical and pharmaceutical development into marketed products.

  15. LINKS to NATIONAL WEATHER SERVICE MARINE FORECAST OFFICES

    Science.gov (United States)

    ; Organization Search Search Landlubber's forecast: "City, St" or zip code (Pan/Zoom for Marine) Search SERVICE MARINE FORECAST OFFICES (Click on the NWS Forecast Center/Office of interest to link to that Marine Forecasts in text form ) Coastal NWS Forecast Offices have regionally focused marine webpages

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

    Science.gov (United States)

    Everaert, Gert; Deschutter, Yana; De Troch, Marleen; Janssen, Colin R.; De Schamphelaere, Karel

    2018-05-01

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

  17. Potential Antiviral Agents from Marine Fungi: An Overview

    Directory of Open Access Journals (Sweden)

    Soheil Zorofchian Moghadamtousi

    2015-07-01

    Full Text Available Biodiversity of the marine world is only partially subjected to detailed scientific scrutiny in comparison to terrestrial life. Life in the marine world depends heavily on marine fungi scavenging the oceans of lifeless plants and animals and entering them into the nutrient cycle by. Approximately 150 to 200 new compounds, including alkaloids, sesquiterpenes, polyketides, and aromatic compounds, are identified from marine fungi annually. In recent years, numerous investigations demonstrated the tremendous potential of marine fungi as a promising source to develop new antivirals against different important viruses, including herpes simplex viruses, the human immunodeficiency virus, and the influenza virus. Various genera of marine fungi such as Aspergillus, Penicillium, Cladosporium, and Fusarium were subjected to compound isolation and antiviral studies, which led to an illustration of the strong antiviral activity of a variety of marine fungi-derived compounds. The present review strives to summarize all available knowledge on active compounds isolated from marine fungi with antiviral activity.

  18. Effects of drilling fluids on marine organisms

    International Nuclear Information System (INIS)

    Parrish, P.R.; Duke, T.W.

    1990-01-01

    This paper reports on drilling fluids, also called drilling muds, which are essential to drilling processes in the exploration and production of oil and gas from the U.S. Outer Continental Shelf (OCS). These fluids are usually discharged from drilling platforms into surrounding waters of the OCS and are regulated by the U.S. Environmental Protection Agency (EPA). In a program carried out by the EPA Environmental research Laboratory at Gulf Breeze, Florida, diverse marine species as well as microbiotic and macrobiotic communities were studied. Drilling fluids were toxic to marine organisms in certain concentrations and exposure regimes. Furthermore, the fluids adversely affected the benthos physically by burying them or by altering the substrates. Toxicity of the drilling-fluid components, used drilling fluids from active Gulf of Mexico sites, and laboratory-prepared drilling fluids varied considerably. for example 96-h LC 50 s were from 25 μ liter -1 to > 1500 μl liter -1 for clams, larval lobsters, mysids, and grass shrimp. In most instances, mortality was significantly (α = 0.05) correlated with the diesel-oil content of the fluids collected from the Gulf of Mexico. Data and model simulations suggest a rapid dilution of drilling fluids released into OCS waters, resulting in concentrations below the acute-effect concentration for the water column organisms tested

  19. ORTHOMYXO- AND PARAMYXOVIRUSES IN MARINE MAMMALS

    Directory of Open Access Journals (Sweden)

    Marina G. Gulyaeva

    2018-01-01

    Full Text Available Abstract. Aim. Marine mammals play the role of "sentries", standing guard over the health and functioning of marine ecosystems. The analysis of data reported in literature was carried out to understand and to evaluate a circulation of representatives of the Orthomyxoviridae and Paramyxoviridae, dangerous pathogens capable to cause morbidity and mortality in marine warm-blooded animals. Discussion. In the population of marine animals, in the available literature, no more than twenty infectious diseases were described. At the same time, according to preliminary estimates, about 15% of marine mammals die from indicated diseases. Previous studies conducted by various groups of scientists have already shown the circulation of various viral pathogens, which cause different infections in these animals. The present fact indicates the important role of marine mammals in the ecology and spreading of a number of viruses. In accordance with a literature data, representatives of Orthomixoviruses and Paramyxoviruses are among the most dangerous pathogens, which may infect this type of animals. Thus, it was suggested that seals may be infected with a wide range of influenza viruses without prior adaptation. It was emphasized that pinnipeds are one of the reservoir of a human influenza B virus in nature. Infections caused by morbilliviruses, can be the reason of epizootics in a population of seals and among the other species of marine mammals. Signs of a disease are similar to the clinic of carnivore plague. Main conclusions. The data presented in literature is extremely not enough for fully understanding a role of marine mammals as hosts or carriers of potential zoonotic pathogens, such as avian influenza virus (AIV, morbilliviruses and others. Thus, this issue requires further more detailed study.

  20. 75 FR 18095 - America's Marine Highway Program

    Science.gov (United States)

    2010-04-09

    ... Marine Highway Transportation. Authority: Energy Independence and Security Act of 2007, Sections 1121...] RIN 2133-AB70 America's Marine Highway Program AGENCY: Maritime Administration, Department of... interim final rule that established America's Marine Highway Program, under which the Secretary will...