Deep ocean model penetrator experiments

International Nuclear Information System (INIS)

Freeman, T.J.; Burdett, J.R.F.

1986-01-01

Preliminary trials of experimental model penetrators in the deep ocean have been conducted as an international collaborative exercise by participating members (national bodies and the CEC) of the Engineering Studies Task Group of the Nuclear Energy Agency's Seabed Working Group. This report describes and gives the results of these experiments, which were conducted at two deep ocean study areas in the Atlantic: Great Meteor East and the Nares Abyssal Plain. Velocity profiles of penetrators of differing dimensions and weights have been determined as they free-fell through the water column and impacted the sediment. These velocity profiles are used to determine the final embedment depth of the penetrators and the resistance to penetration offered by the sediment. The results are compared with predictions of embedment depth derived from elementary models of a penetrator impacting with a sediment. It is tentatively concluded that once the resistance to penetration offered by a sediment at a particular site has been determined, this quantity can be used to sucessfully predict the embedment that penetrators of differing sizes and weights would achieve at the same site

Laboratory Experiments to Stimulate CO2 Ocean Disposal

International Nuclear Information System (INIS)

Masutani, S.M.

1997-01-01

This Technical Progress Report summarizes activities conducted over the period 8/16/96-2/15/97 as part of this project. This investigation responds to the possibility that restrictions on greenhouse gas emissions may be imposed in the future to comply with the Framework Convention on Climate Change. The primary objective of the investigation is to obtain experimental data that can be applied to assess the technical feasibility and environmental impacts of oceanic containment strategies to limit release of carbon dioxide (CO 2 ) from coal and other fossil fuel combustion systems into the atmosphere. Critical technical uncertainties of ocean disposal of CO 2 will be addressed by performing experiments that: (1) characterize size spectra and velocities of a dispersed CO 2 phase in the near-field of a discharge jet; and (2) estimate rates of mass transfer from dissolving droplets of liquid CO 2 encased in a thin hydrate shell. Experiments will be conducted in a laboratory facility that can reproduce conditions in the ocean to depths of 600 m (1,969 ft). Between 8/16/96 and 2/15/97, activities focused on modifications to the experimental apparatus and the testing of diagnostics. Following completion of these tasks, experiments will be initiated and will continue through the end of the 36 month period of performance. Major accomplishments of this reporting period were: (1) delivery, set-up, and testing of the PDPA (Phase Doppler Particle Analyzer), which will be the principal diagnostic of the continuous CO 2 jet injection tests; (2) presentation of research papers and posters at the 212th American Chemical Society National Meeting and the Third International Conference on Carbon Dioxide Removal; (3) participation in the 4th Expert Workshop on Ocean Storage of Carbon Dioxide; (4) execution of an Agreement with ABB Management, Ltd. to support and extend the activities of this grant; and (5) initiation of research collaborations with Dr. P.M. Haugen of the University of

Community respiration/production and bacterial activity in the upper water column of the central Arctic Ocean

Science.gov (United States)

Sherr, Barry F.; Sherr, Evelyn B.

2003-04-01

Community metabolism (respiration and production) and bacterial activity were assessed in the upper water column of the central Arctic Ocean during the SHEBA/JOIS ice camp experiment, October 1997-September 1998. In the upper 50 m, decrease in integrated dissolved oxygen (DO) stocks over a period of 124 d in mid-winter suggested a respiration rate of ˜3.3 nM O 2 h -1 and a carbon demand of ˜4.5 gC m -2. Increase in 0-50 m integrated stocks of DO during summer implied a net community production of ˜20 gC m -2. Community respiration rates were directly measured via rate of decrease in DO in whole seawater during 72-h dark incubation experiments. Incubation-based respiration rates were on average 3-fold lower during winter (11.0±10.6 nM O 2 h -1) compared to summer (35.3±24.8 nM O 2 h -1). Bacterial heterotrophic activity responded strongly, without noticeable lag, to phytoplankton growth. Rate of leucine incorporation by bacteria (a proxy for protein synthesis and cell growth) increased ˜10-fold, and the cell-specific rate of leucine incorporation ˜5-fold, from winter to summer. Rates of production of bacterial biomass in the upper 50 m were, however, low compared to other oceanic regions, averaging 0.52±0.47 ngC l -1 h -1 during winter and 5.1±3.1 ngC l -1 h -1 during summer. Total carbon demand based on respiration experiments averaged 2.4±2.3 mgC m -3 d -1 in winter and 7.8±5.5 mgC m -3 d -1 in summer. Estimated bacterial carbon demand based on bacterial productivity and an assumed 10% gross growth efficiency was much lower, averaging about 0.12±0.12 mgC m -3 d -1 in winter and 1.3±0.7 mgC m -3 d -1 in summer. Our estimates of bacterial activity during summer were an order of magnitude less than rates reported from a summer 1994 study in the central Arctic Ocean, implying significant inter-annual variability of microbial processes in this region.

LABORATORY EXPERIMENTS TO SIMULATE CO2 OCEAN DISPOSAL

Energy Technology Data Exchange (ETDEWEB)

Stephen M. Masutani

1999-12-31

This Final Technical Report summarizes the technical accomplishments of an investigation entitled ''Laboratory Experiments to Simulate CO{sub 2} Ocean Disposal'', funded by the U.S. Department of Energy's University Coal Research Program. This investigation responds to the possibility that restrictions on greenhouse gas emissions may be imposed in the future to comply with the Framework Convention on Climate Change. The primary objective of the investigation was to obtain experimental data that can be applied to assess the technical feasibility and environmental impacts of oceanic containment strategies to limit release of carbon dioxide (CO{sub 2}) from coal and other fossil fuel combustion systems into the atmosphere. A number of critical technical uncertainties of ocean disposal of CO{sub 2} were addressed by performing laboratory experiments on liquid CO{sub 2} jet break-up into a dispersed droplet phase, and hydrate formation, under deep ocean conditions. Major accomplishments of this study included: (1) five jet instability regimes were identified that occur in sequence as liquid CO{sub 2} jet disintegration progresses from laminar instability to turbulent atomization; (2) linear regression to the data yielded relationships for the boundaries between the five instability regimes in dimensionless Ohnesorge Number, Oh, and jet Reynolds Number, Re, space; (3) droplet size spectra was measured over the full range of instabilities; (4) characteristic droplet diameters decrease steadily with increasing jet velocity (and increasing Weber Number), attaining an asymptotic value in instability regime 5 (full atomization); and (5) pre-breakup hydrate formation appears to affect the size distribution of the droplet phase primary by changing the effective geometry of the jet.

NODC Standard Format Coastal Ocean Wave and Current (F181) Data from the Atlantic Remote Sensing Land/Ocean Experiment (ARSLOE) (1980) (NODC Accession 0014202)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains time series coastal ocean wave and current data collected during the Atlantic Remote Sensing Land/Ocean Experiment (ARSLOE). ARSLOE was...

Measuring Ocean Literacy in Pre-Service Teachers: Psychometric Properties of the Greek Version of the Survey of Ocean Literacy and Experience (SOLE)

Science.gov (United States)

Markos, Angelos; Boubonari, Theodora; Mogias, Athanasios; Kevrekidis, Theodoros

2017-01-01

The aim of the present study was to respond to the increasing demand for comprehensive tools for the measurement of ocean literacy, by investigating the psychometric characteristics of a Greek version of the Survey of Ocean Literacy and Experience (SOLE), an instrument that assesses conceptual understanding of general ocean sciences content,…

The Indian Ocean Experiment : Widespread air pollution from South and Southeast Asia

NARCIS (Netherlands)

Lelieveld, J; Crutzen, PJ; Ramanathan, A.; Andreae, MO; Brenninkmeijer, CAM; Campos, T; Cass, GR; Dickerson, RR; Fischer, H; de Gouw, JA; Hansel, A; Jefferson, A; Kley, D; de Laat, ATJ; Lal, S; Lawrence, MG; Lobert, JM; Mayol-Bracero, OL; Mitra, AP; Novakov, T; Oltmans, SJ; Prather, KA; Reiner, T; Rodhe, H; Scheeren, HA; Sikka, D; Williams, J

2001-01-01

The Indian Ocean Experiment (INDOEX) was an international, multiplatform field campaign to measure Long-range transport of air pollution from South and Southeast Asia toward the Indian Ocean during the dry monsoon season in January to March 1999. Surprisingly high pollution Levels were observed over

Design of Field Experiments for Adaptive Sampling of the Ocean with Autonomous Vehicles

Science.gov (United States)

Zheng, H.; Ooi, B. H.; Cho, W.; Dao, M. H.; Tkalich, P.; Patrikalakis, N. M.

2010-05-01

Due to the highly non-linear and dynamical nature of oceanic phenomena, the predictive capability of various ocean models depends on the availability of operational data. A practical method to improve the accuracy of the ocean forecast is to use a data assimilation methodology to combine in-situ measured and remotely acquired data with numerical forecast models of the physical environment. Autonomous surface and underwater vehicles with various sensors are economic and efficient tools for exploring and sampling the ocean for data assimilation; however there is an energy limitation to such vehicles, and thus effective resource allocation for adaptive sampling is required to optimize the efficiency of exploration. In this paper, we use physical oceanography forecasts of the coastal zone of Singapore for the design of a set of field experiments to acquire useful data for model calibration and data assimilation. The design process of our experiments relied on the oceanography forecast including the current speed, its gradient, and vorticity in a given region of interest for which permits for field experiments could be obtained and for time intervals that correspond to strong tidal currents. Based on these maps, resources available to our experimental team, including Autonomous Surface Craft (ASC) are allocated so as to capture the oceanic features that result from jets and vortices behind bluff bodies (e.g., islands) in the tidal current. Results are summarized from this resource allocation process and field experiments conducted in January 2009.

Prevalence of substance abuse among regular degree health science students in Sheba University College in Mekelle Town, Tigray - Ethiopia.

Science.gov (United States)

Hagos, Esietu Gebregazabher; Asfeha, Gebrekidan Gebregzabher; Berihu, Birhane Alem

2016-01-01

Substance abuse (SA) refers to the harmful or hazardous use of psychoactive substances, including alcohol and illicit drugs. The most common substances which are usually abused are alcohol and tobacco. Herein, we assessed the prevalence of SA among regular degree health science students of the Sheba University College (SUC). A cross-sectional survey was carried out among 1076 SUC students using self-administered structured questionnaire. The simple sampling technique was used to select students. Descriptive statistics, bivariate, and multivariate analysis were done. The overall prevalence of "ever used substance" for at least one was 45.5%. The most commonly used drugs in descending order were alcohol (25.1%), cigarette (11.4%), and khat (9.2%). Male participants, urban setting, peer pressure, personal pleasure, and academic dissatisfaction and pocket money were highly associated with SA. This study showed a lower magnitude (45.6% ever use and 21% still using) of SA among students' compared to other studies. Even if a considerable decrease in SA among study subjects, the creation of awareness and health education should be continued to fully combat the problem of abuse.

Isotopes as tracers of the oceanic circulation: Results from the World Ocean Circulation Experiment

International Nuclear Information System (INIS)

Schlosser, P.; Jenkins, W.J.; Key, R.; Lupton, J.

2002-01-01

During the past decades, natural and anthropogenic isotopes such as tritium ( 3 H), radiocarbon ( 14 C), 3 He, or the stable isotopes of water have been used in studies of the dynamics of natural systems. Early applications of tracers to studies of the ocean were directed at determination of circulation patterns and mean residence times of specific water masses, as well as estimates of mixing coefficients. These exploratory studies suggested that tracers can add significantly to our understanding of the oceanic circulation. In order to fully exploit this potential, the first global tracer study, the GEochemical Ocean SECtions Study (GEOSECS), was launched. From the GEOSECS results it was immediately apparent that very close coordination of tracer programs with physical oceanography studies is required for full utilization of tracer data. During the 1980s plans for the World OCean Experiment (WOCE) were developed. As part of its Hydrographic Program (WHP), especially during the one-time survey, a set of tracers were measured on a global scale with unprecedented spatial resolution (both lateral and vertical). The original plan included a larger number of tracers (CFCs, 3 H/ 3 He, 14 C, 39 Ar, stable isotopes of water, helium isotopes, 228 Ra, 90 Sr, 137 Cs, 85 Kr) than could actually be measured systematically (CFCs, 3 H/ 3 He, 14 C, H 2 18 O/H 2 16 O, helium isotopes). Nevertheless, the resulting data set, which presently is under evaluation, exceeds those obtained from pre-WOCE tracer studies by a wide margin. In this contribution, we describe the existing WOCE data set and demonstrate the type of results that can be expected from its interpretation on the basis of a few selected examples. These examples include: (1) the application of tritium and 3 He to studies of the ventilation of the upper waters in the Pacific Ocean, (2) the spreading of intermediate water in the Pacific and Indian oceans as derived from the distribution of 3 He, and (3) the evaluation of

Material Evidence for Ocean Impact from Shock-Metamorphic Experiments

Science.gov (United States)

Miura, Y.; Takayama, K.; Iancu, O. G.

1993-07-01

Continental impact reveals an excavated crater that has few fresh fine ejecta showing major high shock metamorphism due to weathering [1]. A giant ocean impact rarely remains as an excavated crater mainly due to crushing by dynamic plate-tectonic movements on the crust [2]. However, all impact materials, including fine-grained ejecta, can be obtained with artificial impact experiments [3]. The purpose of this study is to discuss material evidence for ocean impact based on shock-metamorphic experiments. Artificial impact experiments indicate that fine shocked quartz (SQ) aggregates can be formed on several target rocks (Table 1) [1]. It is found in Table 1 that (1) the largest-density deviation of SQ grain is found not at the wall-rock or the impact crater but at fine-grained ejecta, and (2) silica-poor rocks of basalt, gabbro, and anorthosite can also make fine SQ aggregates by impact. Table 1, which appears here in the hard copy, shows formations of fine shocked quartz aggregates from ocean-floor rocks of basalt, gabbroic anorthosite, and granite [3]. An asteroid (about 10 km across) hits the Earth ~65 m.y. ago [4] to result in global catastrophe by titanic explosion and climate change. But shocked quartz grains found in the K/T boundary layer were considered to come from crystalline continental rocks [5]. The present result as listed in Table 1 indicates that fine SQ aggregates can also be formed at sea-floor basaltic and gabbroic rocks [3]. The present result of formation of the SQ grains from sea- floor target rocks is nearly consistent with the finding of a sea-impact crater at the K/T boundary near the Caribbean [6]. Impact-induced volcanism at the K/T boundary can explained by the penetration from thin ocean crust to upper mantle reservoirs, if giant impact of a 10-km- diameter asteroid hit the ocean [2,7]. The present result can explain "phreatomagmatic (magmatic vapor) explosion," which is created by abrupt boiling between high-temperature magma and cold

The North Slope of Alaska and Adjacent Arctic Ocean (NSA/AAO) cart site begins operation: Collaboration with SHEBA and FIRE

Energy Technology Data Exchange (ETDEWEB)

Zak, D. B.; Church, H.; Ivey, M.; Yellowhorse, L.; Zirzow, J.; Widener, K. B.; Rhodes, P.; Turney, C.; Koontz, A.; Stamnes, K.; Storvold, R.; Eide, H. A.; Utley, P.; Eagan, R.; Cook, D.; Hart, D.; Wesely, M.

2000-04-04

Since the 1997 Atmospheric Radiation Measurement (ARM) Science Team Meeting, the North Slope of Alaska and Adjacent Arctic Ocean (NSA/AAO) Cloud and Radiation Testbed (CART) site has come into being. Much has happened even since the 1998 Science Team Meeting at which this paper was presented. To maximize its usefulness, this paper has been updated to include developments through July 1998.

Inverse problem of Ocean Acoustic Tomography (OAT) - A numerical experiment

Digital Repository Service at National Institute of Oceanography (India)

Murty, T.V.R.; Somayajulu, Y.K.; Mahadevan, R.; Murty, C.S.

Acoustic model simulation experiments related to the forward and inverse aspects of ocean tomography have been taken up with a view to estimate the vertical sound speed field by inverting the travel time data. Two methods of inversion have been...

Development of a Continuous Phytoplankton Culture System for Ocean Acidification Experiments

Directory of Open Access Journals (Sweden)

Cathryn Wynn-Edwards

2014-06-01

Full Text Available Around one third of all anthropogenic CO2 emissions have been absorbed by the oceans, causing changes in seawater pH and carbonate chemistry. These changes have the potential to affect phytoplankton, which are critically important for marine food webs and the global carbon cycle. However, our current knowledge of how phytoplankton will respond to these changes is limited to a few laboratory and mesocosm experiments. Long-term experiments are needed to determine the vulnerability of phytoplankton to enhanced pCO2. Maintaining phytoplankton cultures in exponential growth for extended periods of time is logistically difficult and labour intensive. Here we describe a continuous culture system that greatly reduces the time required to maintain phytoplankton cultures, and minimises variation in experimental pCO2 treatments over time. This system is simple, relatively cheap, flexible, and allows long-term experiments to be performed to further our understanding of chronic responses and adaptation by phytoplankton species to future ocean acidification.

Prevalence of substance abuse among regular degree health science students in Sheba University College in Mekelle Town, Tigray - Ethiopia

Directory of Open Access Journals (Sweden)

Esietu Gebregazabher Hagos

2016-01-01

Full Text Available Background: Substance abuse (SA refers to the harmful or hazardous use of psychoactive substances, including alcohol and illicit drugs. The most common substances which are usually abused are alcohol and tobacco. Herein, we assessed the prevalence of SA among regular degree health science students of the Sheba University College (SUC. Materials and Methods: A cross-sectional survey was carried out among 1076 SUC students using self-administered structured questionnaire. The simple sampling technique was used to select students. Descriptive statistics, bivariate, and multivariate analysis were done. Results: The overall prevalence of “ever used substance” for at least one was 45.5%. The most commonly used drugs in descending order were alcohol (25.1%, cigarette (11.4%, and khat (9.2%. Male participants, urban setting, peer pressure, personal pleasure, and academic dissatisfaction and pocket money were highly associated with SA. Conclusion: This study showed a lower magnitude (45.6% ever use and 21% still using of SA among students' compared to other studies. Even if a considerable decrease in SA among study subjects, the creation of awareness and health education should be continued to fully combat the problem of abuse.

DORADO/DOLPHIN: A Unique Semi-submersible Autonomous Vehicle for Ocean Field Experiments.

Science.gov (United States)

Wallace, D.

2016-02-01

The Ocean Science and Technology research group (CERC.OCEAN) at Dalhousie University focuses on new approaches to the design and development of autonomous platforms to study biogeochemical and ecological changes in the world's oceans. Mesoscale "patch" experiments involving tracers are used to test hypotheses (e.g. iron fertilization) and examine near-surface processes and air-sea exchange. Such experiments typically require mapping of rapidly-evolving properties on scales of 10's to 100's of kilometers. These experiments typically employ a research vessel to monitor patch movement and to support process studies: however allocation of expensive vessel time between these uses can be problematic. We present a class of autonomous vehicle with unique potential for mesoscale mapping and experimental science at sea. The Dorado/Dolphin semi-submersibles, manufactured by International Submarine Engineering Ltd., travel just below the sea surface. A surface-piercing, "snorkel" mast allows use of a diesel engine allowing speeds of up to 16 knots and sufficient power for support of complex payloads. A tow-body can profile to 200m. The mast allows air sampling with near-zero atmospheric disturbance as well as remote sensing of the sea surface. The characteristics of this type of vehicle will be compared with those of other available platforms. We will report on our adaptation of the vehicle for measurement of gases and purposeful tracers (e.g. SF5CF3) as well as properties such as T, S, pCO2, O2, fluorescence, etc. and present and solicit ideas for the vehicles' further application/use for ocean science.

Surface wave effects in the NEMO ocean model: Forced and coupled experiments

Science.gov (United States)

Breivik, Øyvind; Mogensen, Kristian; Bidlot, Jean-Raymond; Balmaseda, Magdalena Alonso; Janssen, Peter A. E. M.

2015-04-01

The NEMO general circulation ocean model is extended to incorporate three physical processes related to ocean surface waves, namely the surface stress (modified by growth and dissipation of the oceanic wavefield), the turbulent kinetic energy flux from breaking waves, and the Stokes-Coriolis force. Experiments are done with NEMO in ocean-only (forced) mode and coupled to the ECMWF atmospheric and wave models. Ocean-only integrations are forced with fields from the ERA-Interim reanalysis. All three effects are noticeable in the extratropics, but the sea-state-dependent turbulent kinetic energy flux yields by far the largest difference. This is partly because the control run has too vigorous deep mixing due to an empirical mixing term in NEMO. We investigate the relation between this ad hoc mixing and Langmuir turbulence and find that it is much more effective than the Langmuir parameterization used in NEMO. The biases in sea surface temperature as well as subsurface temperature are reduced, and the total ocean heat content exhibits a trend closer to that observed in a recent ocean reanalysis (ORAS4) when wave effects are included. Seasonal integrations of the coupled atmosphere-wave-ocean model consisting of NEMO, the wave model ECWAM, and the atmospheric model of ECMWF similarly show that the sea surface temperature biases are greatly reduced when the mixing is controlled by the sea state and properly weighted by the thickness of the uppermost level of the ocean model. These wave-related physical processes were recently implemented in the operational coupled ensemble forecast system of ECMWF.

OA Experimental Results - Species response experiments on the effects of ocean acidification, climate change, and deoxygenation

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NWFSC Ocean Acidification (OA) team will conduct a series of species-exposure experiments in the acidification research facility on N. Pacific species of...

Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms

Science.gov (United States)

Perera, Alokya P.; Bopegedera, A. M. R. P.

2014-01-01

The increase in ocean acidity since preindustrial times may have deleterious consequences for marine organisms, particularly those with calcareous structures. We present a laboratory experiment to investigate this impact with general, introductory, environmental, and nonmajors chemistry students. For simplicity and homogeneity, calcite was…

Economics of ocean ranching: experiences, outlook and theory

National Research Council Canada - National Science Library

Ragnar Arnason

2001-01-01

"The author distinguishes between ocean fish farming and ocean ranching. The distinguishing characteristic of ocean ranching is that the released species are unassisted once released into the ocean...

Impacts of dynamical ocean coupling in MJO experiments using NICAM/NICOCO

Science.gov (United States)

Miyakawa, T.

2016-12-01

The cloud-system resolving atmosphereic model NICAM has been successfull in producing Madden-Julian Oscillations(MJOs), having it's prediction skill estimated to be about 4 weeks in a series of hindcast experiments for winter MJO events during 2003-2012 (Miyakawa et al. 2014). A simple mixed-layer ocean model has been applied with nudging towards a prescribed "persistent anomaly SST", which maintains the initial anomaly with a time-varying climatological seasonal cycle. This setup enables the model to interact with an ocean with reasonably realistic SST, and also run in a "forecast mode", without using any observational information after the initial date. A limitation is that under this setup, the model skill drops if the oceanic anomaly rapidly changes after the initial date in the real world. Here we run a recently developed, full 3D-ocean coupled version NICAM-COCO (NICOCO) and explore its impact on MJO simulations. Dynamical ocean models can produce oceanic waves/currents, but will also have a bias and drift away from reality. In a sub-seasonal simulation (an initial problem), it is essential to compare the merit of having better represented oceanic signals and the demerit of bias/drift. A test case simulation series featuring an MJO that triggered the abrupt termination of a major El Nino in 1998 shows that the abrupt termination occurs in all 9 simulation members, highlighting the merit of ocean coupling. However, this is a case where oceanic signals are at its extremes. We carried out an estimation of MJO prediction skill for a preliminary 1-degree mesh ocean version of NICOCO in a similar manner to Miyakawa et al. (2014). The MJO skill was degraded for simulations that was initialized at RMM phases 1 and 2 (corresponding to the Indian Ocean), while those initialized at phase 8 (Africa) was not strongly affected. The tendency of the model ocean to overestimate the Maritime Continent warm pool SST possibly delays the eastward propagation of MJO convective

Indian Ocean experiments with a coupled model

Energy Technology Data Exchange (ETDEWEB)

Wainer, I. [Sao Paulo, Univ. (Brazil). Dept. of Oceanography

1997-03-01

A coupled ocean-atmosphere model is used to investigate the equatorial Indian Ocean response to the seasonally varying monsoon winds. Special attention is given to the oceanic response to the spatial distribution and changes in direction of the zonal winds. The Indian Ocean is surrounded by an Asian land mass to the North and an African land mass to the West. The model extends latitudinally between 41 N and 41 S. The asymmetric atmospheric model is driven by a mass source/sink term that is proportional to the sea surface temperature (SST) over the oceans and the heat balance over the land. The ocean is modeled using the Anderson and McCreary reduced-gravity transport model that includes a prognostic equation for the SST. The coupled system is driven by the annual cycle as manifested by zonally symmetric and asymmetric land and ocean heating. They explored the different nature of the equatorial ocean response to various patterns of zonal wind stress forcing in order to isolate the impact of the remote response on the Somali current. The major conclusions are : i) the equatorial response is fundamentally different for easterlies and westerlies, ii) the impact of the remote forcing on the Somali current is a function of the annual cycle, iii) the size of the basin sets the phase of the interference of the remote forcing on the Somali current relative to the local forcing.

A model to estimate volume change due to radiolytic gas bubbles and thermal expansion in solution reactors

International Nuclear Information System (INIS)

Souto, F.J.; Heger, A.S.

2001-01-01

To investigate the effects of radiolytic gas bubbles and thermal expansion on the steady-state operation of solution reactors at the power level required for the production of medical isotopes, a calculational model has been developed. To validate this model, including its principal hypotheses, specific experiments at the Los Alamos National Laboratory SHEBA uranyl fluoride solution reactor were conducted. The following sections describe radiolytic gas generation in solution reactors, the equations to estimate the fuel solution volume change due to radiolytic gas bubbles and thermal expansion, the experiments conducted at SHEBA, and the comparison of experimental results and model calculations. (author)

Meteorological conditions in the central Arctic summer during the Arctic Summer Cloud Ocean Study (ASCOS

Directory of Open Access Journals (Sweden)

M. Tjernström

2012-08-01

Full Text Available Understanding the rapidly changing climate in the Arctic is limited by a lack of understanding of underlying strong feedback mechanisms that are specific to the Arctic. Progress in this field can only be obtained by process-level observations; this is the motivation for intensive ice-breaker-based campaigns such as the Arctic Summer Cloud-Ocean Study (ASCOS, described here. However, detailed field observations also have to be put in the context of the larger-scale meteorology, and short field campaigns have to be analysed within the context of the underlying climate state and temporal anomalies from this.

To aid in the analysis of other parameters or processes observed during this campaign, this paper provides an overview of the synoptic-scale meteorology and its climatic anomaly during the ASCOS field deployment. It also provides a statistical analysis of key features during the campaign, such as key meteorological variables, the vertical structure of the lower troposphere and clouds, and energy fluxes at the surface. In order to assess the representativity of the ASCOS results, we also compare these features to similar observations obtained during three earlier summer experiments in the Arctic Ocean: the AOE-96, SHEBA and AOE-2001 expeditions.

We find that these expeditions share many key features of the summertime lower troposphere. Taking ASCOS and the previous expeditions together, a common picture emerges with a large amount of low-level cloud in a well-mixed shallow boundary layer, capped by a weak to moderately strong inversion where moisture, and sometimes also cloud top, penetrate into the lower parts of the inversion. Much of the boundary-layer mixing is due to cloud-top cooling and subsequent buoyant overturning of the cloud. The cloud layer may, or may not, be connected with surface processes depending on the depths of the cloud and surface-based boundary layers and on the relative strengths of surface-shear and

Direct Experiments on the Ocean Disposal of Fossil Fuel CO2

Energy Technology Data Exchange (ETDEWEB)

Barry, James, P.

2010-05-26

Funding from DoE grant # FG0204-ER63721, Direct Experiments on the Ocean Disposal of Fossil Fuel CO2, supposed several postdoctoral fellows and research activities at MBARI related to ocean CO2 disposal and the biological consequences of high ocean CO2 levels on marine organisms. Postdocs supported on the project included Brad Seibel, now an associate professor at the University of Rhode Island, Jeff Drazen, now an associate professor at the University of Hawaii, and Eric Pane, who continues as a research associate at MBARI. Thus, the project contributed significantly to the professional development of young scientists. In addition, we made significant progress in several research areas. We continued several deep-sea CO2 release experiments using support from DoE and MBARI, along with several collaborators. These CO2 release studies had the goal of broadening our understanding of the effects of high ocean CO2 levels on deep sea animals in the vicinity of potential release sites for direct deep-ocean carbon dioxide sequestration. Using MBARI ships and ROVs, we performed these experiments at depths of 3000 to 3600 m, where liquid CO2 is heavier than seawater. CO2 was released into small pools (sections of PVC pipe) on the seabed, where it dissolved and drifted downstream, bathing any caged animals and sediments in a CO2-rich, low-pH plume. We assessed the survival of organisms nearby. Several publications arose from these studies (Barry et al. 2004, 2005; Carman et al. 2004; Thistle et al. 2005, 2006, 2007; Fleeger et al. 2006, 2010; Barry and Drazen 2007; Bernhard et al. 2009; Sedlacek et al. 2009; Ricketts et al. in press; Barry et al, in revision) concerning the sensitivity of animals to low pH waters. Using funds from DoE and MBARI, we designed and fabricated a hyperbaric trap-respirometer to study metabolic rates of deep-sea fishes under high CO2 conditions (Drazen et al, 2005), as well as a gas-control aquarium system to support laboratory studies of the

Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

International Nuclear Information System (INIS)

Washington, W.M.; Meehl, G.A.

1990-01-01

The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming

Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

International Nuclear Information System (INIS)

Washington, W.M.; Meehl, G.A.

1991-01-01

The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming. 46 refs.; 20 figs.; 1 tab

Effects of ocean acidification on pelagic carbon fluxes in a mesocosm experiment

NARCIS (Netherlands)

Spilling, K.; Schulz, K.G.; Paul, A.J.; Boxhammer, T.; Achterberg, E.P.; Hornick, T.; Lischka, S.; Stuhr, A.; Bermúdez, R.; Czerny, J.; Crawfurd, K.; Brussaard, C.P.D.; Grossart, H.-P.; Riebesell, U.

2016-01-01

About a quarter of anthropogenic CO2 emissions are currently taken up by the oceans, decreasing seawater pH. We performed a mesocosm experiment in the Baltic Sea in order to investigate the consequences of increasing CO2 levels on pelagic carbon fluxes. A gradient of different CO2 scenarios, ranging

The atmospheric boundary layer response to the dynamic new Arctic Ocean

Science.gov (United States)

Wu, D. L.; Ganeshan, M.

2016-12-01

The increasing ice-free area in the Arctic Ocean has transformed its climate system to one with more dynamic boundary layer clouds and seasonal sea ice. During the fall freeze season, the surface sensible heat flux (SSHF) is a crucial mechanism for the loss of excessive ocean heat to the atmosphere, and it has been speculated to play an important role in the recent cloud cover increase and boundary layer (BL) instability observed in the Beaufort and Chukchi seas. Based on multi-year Japanese cruise ship observations from the ice-strengthened R/V Mirai, we are able to characterize the late summer and early fall ocean-BL interactions in this region. Although the BL is found to be well-mixed more than 90% of the time, the SSHF can explain only 10% of the mixed layer height variability. It is the cloud-generated convective turbulence that apparently dominates BL mixing in this ice-free region, which is similar to previous in-situ observations (SHEBA, ASCOS) over sea ice. The SSHF, however, may contribute to BL instability during conditions of uplift (low-pressure), and the presence of the highly stable stratus cloud regime. The efficiency of sensible heat exchange is low during cold air advection (associated with the stratocumulus cloud regime) despite an enhanced ocean-atmosphere temperature difference (ΔT). In general, surface-generated mixing is favored during episodes of high surface wind speeds as opposed to pronounced ΔT. Our analysis suggests a weak local response of the boundary layer stability to the loss of sea ice cover during late summer, which is masked by the strong influence of the large-scale circulation (and clouds). Apart from the fall season, we also studied the Arctic Ocean BL properties during the cold months (Nov-Apr) using multi-year satellite measurements (COSMIC RO). As the boundary layer is typically stable at this time, one might expect major differences in the nature of surface-atmosphere coupling compared to that observed during late

Quantifying pCO2 in biological ocean acidification experiments: A comparison of four methods.

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Watson, Sue-Ann; Fabricius, Katharina E; Munday, Philip L

2017-01-01

Quantifying the amount of carbon dioxide (CO2) in seawater is an essential component of ocean acidification research; however, equipment for measuring CO2 directly can be costly and involve complex, bulky apparatus. Consequently, other parameters of the carbonate system, such as pH and total alkalinity (AT), are often measured and used to calculate the partial pressure of CO2 (pCO2) in seawater, especially in biological CO2-manipulation studies, including large ecological experiments and those conducted at field sites. Here we compare four methods of pCO2 determination that have been used in biological ocean acidification experiments: 1) Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity (VINDTA) measurement of dissolved inorganic carbon (CT) and AT, 2) spectrophotometric measurement of pHT and AT, 3) electrode measurement of pHNBS and AT, and 4) the direct measurement of CO2 using a portable CO2 equilibrator with a non-dispersive infrared (NDIR) gas analyser. In this study, we found these four methods can produce very similar pCO2 estimates, and the three methods often suited to field-based application (spectrophotometric pHT, electrode pHNBS and CO2 equilibrator) produced estimated measurement uncertainties of 3.5-4.6% for pCO2. Importantly, we are not advocating the replacement of established methods to measure seawater carbonate chemistry, particularly for high-accuracy quantification of carbonate parameters in seawater such as open ocean chemistry, for real-time measures of ocean change, nor for the measurement of small changes in seawater pCO2. However, for biological CO2-manipulation experiments measuring differences of over 100 μatm pCO2 among treatments, we find the four methods described here can produce similar results with careful use.

Retrospective satellite ocean color analysis of purposeful and natural ocean iron fertilization

Science.gov (United States)

Westberry, Toby K.; Behrenfeld, Michael J.; Milligan, Allen J.; Doney, Scott C.

2013-03-01

Significant effort has been invested in understanding the role of iron in marine ecosystems over the past few decades. What began as shipboard amendment experiments quickly grew into a succession of in situ, mesoscale ocean iron fertilization (OIF) experiments carried out in all three high nutrient low chlorophyll (HNLC) regions of the world ocean. Dedicated process studies have also looked at regions of the ocean that are seasonally exposed to iron-replete conditions as natural OIF experiments. However, one problem common to many OIF experiments is determination of biological response beyond the duration of the experiment (typicallyfloristic shifts in the phytoplankton community. Further, a consistent pattern of decreased satellite fluorescence efficiency (FLH:Chl or ϕf) following OIF is observed that is in agreement with current understanding of phytoplankton physiological responses to relief from iron stress. The current study extends our ability to retrieve phytoplankton physiology from space-based sensors, strengthens the link between satellite fluorescence and iron availability, and shows that satellite ocean color analyses provide a unique tool for monitoring OIF experiments.

Modeling, Simulation, and Experiment of Switched Reluctance Ocean Current Generator System

Directory of Open Access Journals (Sweden)

Hao Chen

2013-01-01

Full Text Available This paper presents nonlinear simulation model of switched reluctance (SR ocean current generator system on MATLAB/SIMULINK with describing the structure of generator system. The developed model is made up of main model, rotor position calculation module, controller module, gate module, power converter module, phase windings module, flux-linkage module, torque module, and power calculation module. The magnetization curves obtained by two-dimensional finite-element electromagnetic field calculation and the conjugated magnetic energy graphics obtained from the three-dimensional graphics of flux linkage are stored in the “Lookup Table” modules on MATLAB/SIMULINK. The hardware of the developed three-phase 12/8 structure SR ocean current generator system prototype with the experimental platform is presented. The simulation of the prototype is performed by the developed models, and the experiments have been carried out under the same condition with different output power, turn-off angle, and rotor speed. The simulated phase current waveforms agree well with the tested phase current waveforms experimentally. The simulated output voltage curves agree well with the tested output voltage curves experimentally. It is shown that the developed nonlinear simulation model of the three-phase 12/8 structure SR ocean current generator system is valid.

ANL pre analysis of the SHEBA/CERES experiments

International Nuclear Information System (INIS)

Palmiotti, G.; Smith, M.; Klann, R.; Fujita, E.; Imel, G.

2000-01-01

The French and British nuclear programs have prepared a series of natural uranium oxide fuel samples spiked with small amounts of the individual fission products which makeup a large fraction of the total neutron absorption by fission products in spent nuclear fuel. Both programs have utilized these samples in experimental reactors and have inferred the worth of the individual fission products. These results have been used to validate the cross sections used in criticality safety calculations. These measurements constitute a major element in support of spent fuel burnup credit in these countries

The Ocean: Source of Nutrition for the Future. A Learning Experience for Coastal and Oceanic Awareness Studies, No. 305. [Project COAST].

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Delaware Univ., Newark. Coll. of Education.

The question of future sources of food is posed with increasing frequency as the amount of arable land per person decreases with population growth. The role of the ocean as a food supplier is currently being explored. This learning experience is designed for secondary school students. It is divided into four major areas: (1) an overview, (2)…

Atmosphere surface storm track response to resolved ocean mesoscale in two sets of global climate model experiments

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Small, R. Justin; Msadek, Rym; Kwon, Young-Oh; Booth, James F.; Zarzycki, Colin

2018-05-01

It has been hypothesized that the ocean mesoscale (particularly ocean fronts) can affect the strength and location of the overlying extratropical atmospheric storm track. In this paper, we examine whether resolving ocean fronts in global climate models indeed leads to significant improvement in the simulated storm track, defined using low level meridional wind. Two main sets of experiments are used: (i) global climate model Community Earth System Model version 1 with non-eddy-resolving standard resolution or with ocean eddy-resolving resolution, and (ii) the same but with the GFDL Climate Model version 2. In case (i), it is found that higher ocean resolution leads to a reduction of a very warm sea surface temperature (SST) bias at the east coasts of the U.S. and Japan seen in standard resolution models. This in turn leads to a reduction of storm track strength near the coastlines, by up to 20%, and a better location of the storm track maxima, over the western boundary currents as observed. In case (ii), the change in absolute SST bias in these regions is less notable, and there are modest (10% or less) increases in surface storm track, and smaller changes in the free troposphere. In contrast, in the southern Indian Ocean, case (ii) shows most sensitivity to ocean resolution, and this coincides with a larger change in mean SST as ocean resolution is changed. Where the ocean resolution does make a difference, it consistently brings the storm track closer in appearance to that seen in ERA-Interim Reanalysis data. Overall, for the range of ocean model resolutions used here (1° versus 0.1°) we find that the differences in SST gradient have a small effect on the storm track strength whilst changes in absolute SST between experiments can have a larger effect. The latter affects the land-sea contrast, air-sea stability, surface latent heat flux, and the boundary layer baroclinicity in such a way as to reduce storm track activity adjacent to the western boundary in the N

Preparing to predict: The Second Autonomous Ocean Sampling Network (AOSN-II) experiment in the Monterey Bay

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Ramp, S. R.; Davis, R. E.; Leonard, N. E.; Shulman, I.; Chao, Y.; Robinson, A. R.; Marsden, J.; Lermusiaux, P. F. J.; Fratantoni, D. M.; Paduan, J. D.; Chavez, F. P.; Bahr, F. L.; Liang, S.; Leslie, W.; Li, Z.

2009-02-01

The Autonomous Ocean Sampling Network Phase Two (AOSN-II) experiment was conducted in and offshore from the Monterey Bay on the central California coast during July 23-September 6, 2003. The objective of the experiment was to learn how to apply new tools, technologies, and analysis techniques to adaptively sample the coastal ocean in a manner demonstrably superior to traditional methodologies, and to use the information gathered to improve predictive skill for quantities of interest to end-users. The scientific goal was to study the upwelling/relaxation cycle near an open coastal bay in an eastern boundary current region, particularly as it developed and spread from a coastal headland. The suite of observational tools used included a low-flying aircraft, a fleet of underwater gliders, including several under adaptive autonomous control, and propeller-driven AUVs in addition to moorings, ships, and other more traditional hardware. The data were delivered in real time and assimilated into the Harvard Ocean Prediction System (HOPS), the Navy Coastal Ocean Model (NCOM), and the Jet Propulsion Laboratory implementation of the Regional Ocean Modeling System (JPL/ROMS). Two upwelling events and one relaxation event were sampled during the experiment. The upwelling in both cases began when a pool of cold water less than 13 °C appeared near Cape Año Nuevo and subsequently spread offshore and southward across the bay as the equatorward wind stress continued. The primary difference between the events was that the first event spread offshore and southward, while the second event spread only southward and not offshore. The difference is attributed to the position and strength of meanders and eddies of the California Current System offshore, which blocked or steered the cold upwelled water. The space and time scales of the mesoscale variability were much shorter than have been previously observed in deep-water eddies offshore. Additional process studies are needed to elucidate

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.

Aerosol properties over the Indian Ocean Experiment (INDOEX) campaign area retrieved from ATSR-2

NARCIS (Netherlands)

Robles-Gonzalez, C.; Leeuw, G.de; Decae, R.; Kusmierczyk-Michulec, J.T.; Stammes, P.

2006-01-01

Aerosol retrieved algorithms for ATSR-2 have been applied over land and water using data from the Indian Ocean Experiment (INDOEX) Intensive Field Phase (IFP) in February and March 1999. The goal was the extension of the ATSR-2 algorithms, developed for application over the U.S. east coast and

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

Science.gov (United States)

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

2016-02-01

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

Ocean Acidification Experiments in Large-Scale Mesocosms Reveal Similar Dynamics of Dissolved Organic Matter Production and Biotransformation

Directory of Open Access Journals (Sweden)

Maren Zark

2017-09-01

Full Text Available Dissolved organic matter (DOM represents a major reservoir of carbon in the oceans. Environmental stressors such as ocean acidification (OA potentially affect DOM production and degradation processes, e.g., phytoplankton exudation or microbial uptake and biotransformation of molecules. Resulting changes in carbon storage capacity of the ocean, thus, may cause feedbacks on the global carbon cycle. Previous experiments studying OA effects on the DOM pool under natural conditions, however, were mostly conducted in temperate and coastal eutrophic areas. Here, we report on OA effects on the existing and newly produced DOM pool during an experiment in the subtropical North Atlantic Ocean at the Canary Islands during an (1 oligotrophic phase and (2 after simulated deep water upwelling. The last is a frequently occurring event in this region controlling nutrient and phytoplankton dynamics. We manipulated nine large-scale mesocosms with a gradient of pCO2 ranging from ~350 up to ~1,030 μatm and monitored the DOM molecular composition using ultrahigh-resolution mass spectrometry via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS. An increase of 37 μmol L−1 DOC was observed in all mesocosms during a phytoplankton bloom induced by simulated upwelling. Indications for enhanced DOC accumulation under elevated CO2 became apparent during a phase of nutrient recycling toward the end of the experiment. The production of DOM was reflected in changes of the molecular DOM composition. Out of the 7,212 molecular formulae, which were detected throughout the experiment, ~50% correlated significantly in mass spectrometric signal intensity with cumulative bacterial protein production (BPP and are likely a product of microbial transformation. However, no differences in the produced compounds were found with respect to CO2 levels. Comparing the results of this experiment with a comparable OA experiment in the Swedish Gullmar Fjord, reveals

Near-shore Antarctic pH variability has implications for the design of ocean acidification experiments

Science.gov (United States)

Kapsenberg, Lydia; Kelley, Amanda L.; Shaw, Emily C.; Martz, Todd R.; Hofmann, Gretchen E.

2015-01-01

Understanding how declining seawater pH caused by anthropogenic carbon emissions, or ocean acidification, impacts Southern Ocean biota is limited by a paucity of pH time-series. Here, we present the first high-frequency in-situ pH time-series in near-shore Antarctica from spring to winter under annual sea ice. Observations from autonomous pH sensors revealed a seasonal increase of 0.3 pH units. The summer season was marked by an increase in temporal pH variability relative to spring and early winter, matching coastal pH variability observed at lower latitudes. Using our data, simulations of ocean acidification show a future period of deleterious wintertime pH levels potentially expanding to 7–11 months annually by 2100. Given the presence of (sub)seasonal pH variability, Antarctica marine species have an existing physiological tolerance of temporal pH change that may influence adaptation to future acidification. Yet, pH-induced ecosystem changes remain difficult to characterize in the absence of sufficient physiological data on present-day tolerances. It is therefore essential to incorporate natural and projected temporal pH variability in the design of experiments intended to study ocean acidification biology.

Downscaling ocean conditions: Experiments with a quasi-geostrophic model

Science.gov (United States)

Katavouta, A.; Thompson, K. R.

2013-12-01

The predictability of small-scale ocean variability, given the time history of the associated large-scales, is investigated using a quasi-geostrophic model of two wind-driven gyres separated by an unstable, mid-ocean jet. Motivated by the recent theoretical study of Henshaw et al. (2003), we propose a straightforward method for assimilating information on the large-scale in order to recover the small-scale details of the quasi-geostrophic circulation. The similarity of this method to the spectral nudging of limited area atmospheric models is discussed. Results from the spectral nudging of the quasi-geostrophic model, and an independent multivariate regression-based approach, show that important features of the ocean circulation, including the position of the meandering mid-ocean jet and the associated pinch-off eddies, can be recovered from the time history of a small number of large-scale modes. We next propose a hybrid approach for assimilating both the large-scales and additional observed time series from a limited number of locations that alone are too sparse to recover the small scales using traditional assimilation techniques. The hybrid approach improved significantly the recovery of the small-scales. The results highlight the importance of the coupling between length scales in downscaling applications, and the value of assimilating limited point observations after the large-scales have been set correctly. The application of the hybrid and spectral nudging to practical ocean forecasting, and projecting changes in ocean conditions on climate time scales, is discussed briefly.

Chemical magnetization when determining Thellier paleointensity experiments in oceanic basalts

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Tselebrovskiy, Alexey; Maksimochkin, Valery

2017-04-01

The natural remanent magnetization (NRM) of oceanic basalts selected in the rift zones of the Mid-Atlantic Ridge (MAR) and the Red Sea has been explored. Laboratory simulation shows that the thermoremanent magnetization and chemical remanent magnetization (CRM) in oceanic basalts may be separated by using Tellier-Coe experiment. It was found that the rate of CRM destruction is about four times lower than the rate of the partial thermoremanent magnetization formation in Thellier cycles. The blocking temperatures spectrum of chemical component shifted toward higher temperatures in comparison with the spectrum of primary thermoremanent magnetization. It was revealed that the contribution of the chemical components in the NRM increases with the age of oceanic basalts determined with the analysis of the anomalous geomagnetic field (AGF) and spreading theory. CRM is less than 10% at the basalts aged 0.2 million years, less than 50% at basalts aged 0.35 million years, from 60 to 80% at basalts aged 1 million years [1]. Geomagnetic field paleointensity (Hpl) has been determined through the remanent magnetization of basalt samples of different ages related to Brunhes, Matuyama and Gauss periods of the geomagnetic field polarity. The value of the Hpl determined by basalts of the southern segment of MAR is ranged from 17.5 to 42.5 A/m, by the Reykjanes Ridge basalts — from 20.3 to 44 A/m, by the Bouvet Ridge basalts — from 21.7 to 34.1 A/m. VADM values calculated from these data are in good agreement with the international paleointensity database [2] and PISO-1500 model [3]. Literature 1. Maksimochkin V., Tselebrovskiy A., (2015) The influence of the chemical magnetization of oceanic basalts on determining the geomagnetic field paleointensity by the thellier method, moscow university physics bulletin, 70(6):566-576, 2. Perrin, M., E. Schnepp, and V. Shcherbakov (1998), Update of the paleointensity database, Eos Trans. AGU, 79, 198. 3. Channell JET, Xuan C, Hodell DA (2009

Computational Ocean Acoustics

CERN Document Server

Jensen, Finn B; Porter, Michael B; Schmidt, Henrik

2011-01-01

Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

The OSCAR experiment: using full-waveform inversion in the analysis of young oceanic crust

Science.gov (United States)

Silverton, Akela; Morgan, Joanna; Wilson, Dean; Hobbs, Richard

2017-04-01

The OSCAR experiment aims to derive an integrated model to better explain the effects of heat loss and alteration by hydrothermal fluids, associated with the cooling of young oceanic crust at an axial ridge. High-resolution seismic imaging of the sediments and basaltic basement can be used to map fluid flow pathways between the oceanic crust and the surrounding ocean. To obtain these high-resolution images, we undertake full-waveform inversion (FWI), an advanced seismic imaging technique capable of resolving velocity heterogeneities at a wide range of length scales, from background trends to fine-scale geological/crustal detail, in a fully data-driven automated manner. This technology is widely used within the petroleum sector due to its potential to obtain high-resolution P-wave velocity models that lead to improvements in migrated seismic images of the subsurface. Here, we use the P-wave velocity model obtained from travel-time tomography as the starting model in the application of acoustic, time-domain FWI to a multichannel streamer field dataset acquired in the east Pacific along a profile between the Costa Rica spreading centre and the Ocean Drilling Program (ODP) borehole 504B, where the crust is approximately six million years old. FWI iteratively improves the velocity model by minimizing the misfit between the predicted data and the field data. It seeks to find a high-fidelity velocity model that is capable of matching individual seismic waveforms of the original raw field dataset, with an initial focus on matching the low-frequency components of the early arriving energy. Quality assurance methods adopted during the inversion ensure convergence in the direction of the global minimum. We demonstrate that FWI is able to recover fine-scale, high-resolution velocity heterogeneities within the young oceanic crust along the profile. The highly resolved FWI velocity model is useful in the identification of the layer 2A/2B interface and low-velocity layers that

Lunar Magma Ocean Crystallization: Constraints from Fractional Crystallization Experiments

Science.gov (United States)

Rapp, J. F.; Draper, D. S.

2015-01-01

The currently accepted paradigm of lunar formation is that of accretion from the ejecta of a giant impact, followed by crystallization of a global scale magma ocean. This model accounts for the formation of the anorthosite highlands crust, which is globally distributed and old, and the formation of the younger mare basalts which are derived from a source region that has experienced plagioclase extraction. Several attempts at modelling the crystallization of such a lunar magma ocean (LMO) have been made, but our ever-increasing knowledge of the lunar samples and surface have raised as many questions as these models have answered. Geodynamic models of lunar accretion suggest that shortly following accretion the bulk of the lunar mass was hot, likely at least above the solidus]. Models of LMO crystallization that assume a deep magma ocean are therefore geodynamically favorable, but they have been difficult to reconcile with a thick plagioclase-rich crust. A refractory element enriched bulk composition, a shallow magma ocean, or a combination of the two have been suggested as a way to produce enough plagioclase to account for the assumed thickness of the crust. Recently however, geophysical data from the GRAIL mission have indicated that the lunar anorthositic crust is not as thick as was initially estimated, which allows for both a deeper magma ocean and a bulk composition more similar to the terrestrial upper mantle. We report on experimental simulations of the fractional crystallization of a deep (approximately 100km) LMO with a terrestrial upper mantle-like (LPUM) bulk composition. Our experimental results will help to define the composition of the lunar crust and mantle cumulates, and allow us to consider important questions such as source regions of the mare basalts and Mg-suite, the role of mantle overturn after magma ocean crystallization and the nature of KREEP

The Ocean as a teaching tool: the first MOOC on Ocean Literacy

Science.gov (United States)

Santin, Selvaggia; Santoro, Francesca

2017-04-01

Education its broader understanding (in both formal and informal settings) serves as a high potential channel to reach young citizens. As a lack of sufficient 'Ocean Literacy' has been identified in many countries, this clearly presents a barrier for citizens to engage in ocean responsible behaviour or consider ocean-related careers. In order to sensitize and enable teachers and students to incorporate ocean literacy into educational programmes we build up a first Massive Open Online Course on Emma Platform, an European Multiple MOOC Aggregator that provides a system for the delivery of free, open, online courses in multiple languages from different European universities. Almost 500 students were enrolled from all over the world and we proposed a multi-perspective approach building on the UNESCO experience in the field of education for sustainable development. The course had two sections: a narrative format which introduces to the Ocean Literacy principles, focusing on how to incorporate them into lessons with tips, advice, references and activities; and an interactive section with webinairs which covers contemporary and emerging issues such as seafood, marine pollution and human health, simulating a "real-world experiences" with a problems-solutions approach.

Gradient flux measurements of sea-air DMS transfer during the Surface Ocean Aerosol Production (SOAP) experiment

Science.gov (United States)

Smith, Murray J.; Walker, Carolyn F.; Bell, Thomas G.; Harvey, Mike J.; Saltzman, Eric S.; Law, Cliff S.

2018-04-01

Direct measurements of marine dimethylsulfide (DMS) fluxes are sparse, particularly in the Southern Ocean. The Surface Ocean Aerosol Production (SOAP) voyage in February-March 2012 examined the distribution and flux of DMS in a biologically active frontal system in the southwest Pacific Ocean. Three distinct phytoplankton blooms were studied with oceanic DMS concentrations as high as 25 nmol L-1. Measurements of DMS fluxes were made using two independent methods: the eddy covariance (EC) technique using atmospheric pressure chemical ionization-mass spectrometry (API-CIMS) and the gradient flux (GF) technique from an autonomous catamaran platform. Catamaran flux measurements are relatively unaffected by airflow distortion and are made close to the water surface, where gas gradients are largest. Flux measurements were complemented by near-surface hydrographic measurements to elucidate physical factors influencing DMS emission. Individual DMS fluxes derived by EC showed significant scatter and, at times, consistent departures from the Coupled Ocean-Atmosphere Response Experiment gas transfer algorithm (COAREG). A direct comparison between the two flux methods was carried out to separate instrumental effects from environmental effects and showed good agreement with a regression slope of 0.96 (r2 = 0.89). A period of abnormal downward atmospheric heat flux enhanced near-surface ocean stratification and reduced turbulent exchange, during which GF and EC transfer velocities showed good agreement but modelled COAREG values were significantly higher. The transfer velocity derived from near-surface ocean turbulence measurements on a spar buoy compared well with the COAREG model in general but showed less variation. This first direct comparison between EC and GF fluxes of DMS provides confidence in compilation of flux estimates from both techniques, as well as in the stable periods when the observations are not well predicted by the COAREG model.

Ocean wave-radar modulation transfer functions from the West Coast experiment

Science.gov (United States)

Wright, J. W.; Plant, W. J.; Keller, W. C.; Jones, W. L.

1980-01-01

Short gravity-capillary waves, the equilibrium, or the steady state excitations of the ocean surface are modulated by longer ocean waves. These short waves are the predominant microwave scatterers on the ocean surface under many viewing conditions so that the modulation is readily measured with CW Doppler radar used as a two-scale wave probe. Modulation transfer functions (the ratio of the cross spectrum of the line-of-sight orbital speed and backscattered microwave power to the autospectrum of the line-of-sight orbital speed) were measured at 9.375 and 1.5 GHz (Bragg wavelengths of 2.3 and 13 cm) for winds up to 10 m/s and ocean wave periods from 2-18 s. The measurements were compared with the relaxation-time model; the principal result is that a source of modulation other than straining by the horizontal component of orbital speed, possibly the wave-induced airflow, is responsible for most of the modulation by waves of typical ocean wave period (10 s). The modulations are large; for unit coherence, spectra of radar images of deep-water waves should be proportional to the quotient of the slope spectra of the ocean waves by the ocean wave frequency.

Design of the MISMIP+, ISOMIP+, and MISOMIP ice-sheet, ocean, and coupled ice sheet-ocean intercomparison projects

Science.gov (United States)

Asay-Davis, Xylar; Cornford, Stephen; Martin, Daniel; Gudmundsson, Hilmar; Holland, David; Holland, Denise

2015-04-01

The MISMIP and MISMIP3D marine ice sheet model intercomparison exercises have become popular benchmarks, and several modeling groups have used them to show how their models compare to both analytical results and other models. Similarly, the ISOMIP (Ice Shelf-Ocean Model Intercomparison Project) experiments have acted as a proving ground for ocean models with sub-ice-shelf cavities.As coupled ice sheet-ocean models become available, an updated set of benchmark experiments is needed. To this end, we propose sequel experiments, MISMIP+ and ISOMIP+, with an end goal of coupling the two in a third intercomparison exercise, MISOMIP (the Marine Ice Sheet-Ocean Model Intercomparison Project). Like MISMIP3D, the MISMIP+ experiments take place in an idealized, three-dimensional setting and compare full 3D (Stokes) and reduced, hydrostatic models. Unlike the earlier exercises, the primary focus will be the response of models to sub-shelf melting. The chosen configuration features an ice shelf that experiences substantial lateral shear and buttresses the upstream ice, and so is well suited to melting experiments. Differences between the steady states of each model are minor compared to the response to melt-rate perturbations, reflecting typical real-world applications where parameters are chosen so that the initial states of all models tend to match observations. The three ISOMIP+ experiments have been designed to to make use of the same bedrock topography as MISMIP+ and using ice-shelf geometries from MISMIP+ results produced by the BISICLES ice-sheet model. The first two experiments use static ice-shelf geometries to simulate the evolution of ocean dynamics and resulting melt rates to a quasi-steady state when far-field forcing changes in either from cold to warm or from warm to cold states. The third experiment prescribes 200 years of dynamic ice-shelf geometry (with both retreating and advancing ice) based on a BISICLES simulation along with similar flips between warm and

Social media connecting ocean sciences and the general public: the @OceanSeaIceNPI experiment

Science.gov (United States)

Pavlov, A. K.; Granskog, M. A.; Gerland, S.; Meyer, A.; Hudson, S. R.; Rösel, A.; King, J.; Itkin, P.; Cohen, L.; Dodd, P. A.; de Steur, L.

2016-02-01

As researchers we are constantly being encouraged by funding agencies, policy-makers and journalists to conduct effective outreach and to communicate our latest research findings. As environmental scientists we also understand the necessity of communicating our research to the general public. Many of us wish to become better science communicators but have little time and limited funding available to do so. How can we expend our science communication past project-based efforts that have a limited lifetime? Most critically, how can a small research groups do it without additional resources such as funds and communication officers? Social media is one answer, and has become a powerful and inexpensive tool for communicating science to different target audiences. Many research institutions and researchers are exploring the full breadth of possibilities brought by social media for reaching out to the general public, journalists, policy-makers, stake-holders, and research community. However, smaller research groups and labs are still underrepresented in social media. When it comes to practice, some essential difficulties can be encountered: identifying key target groups, defining the framework for sharing responsibilities and interaction within the research group, and finally, choosing a currently up-to-date social medium as a technical solution for communicating your research. Here, a group of oceanography and sea ice researchers (@OceanSeaIceNPI) share the positive experience of developing and maintaining for more than one year a researcher-driven outreach effort currently implemented through Instagram, Twitter and Facebook. We will present potential pitfalls and challenges that small research groups could face, and how to better overcome them. This will hopefully inspire and help other research groups and labs to conduct their own effective ocean science communication.

Ocean Networks Canada's "Big Data" Initiative

Science.gov (United States)

Dewey, R. K.; Hoeberechts, M.; Moran, K.; Pirenne, B.; Owens, D.

2013-12-01

Ocean Networks Canada operates two large undersea observatories that collect, archive, and deliver data in real time over the Internet. These data contribute to our understanding of the complex changes taking place on our ocean planet. Ocean Networks Canada's VENUS was the world's first cabled seafloor observatory to enable researchers anywhere to connect in real time to undersea experiments and observations. Its NEPTUNE observatory is the largest cabled ocean observatory, spanning a wide range of ocean environments. Most recently, we installed a new small observatory in the Arctic. Together, these observatories deliver "Big Data" across many disciplines in a cohesive manner using the Oceans 2.0 data management and archiving system that provides national and international users with open access to real-time and archived data while also supporting a collaborative work environment. Ocean Networks Canada operates these observatories to support science, innovation, and learning in four priority areas: study of the impact of climate change on the ocean; the exploration and understanding the unique life forms in the extreme environments of the deep ocean and below the seafloor; the exchange of heat, fluids, and gases that move throughout the ocean and atmosphere; and the dynamics of earthquakes, tsunamis, and undersea landslides. To date, the Ocean Networks Canada archive contains over 130 TB (collected over 7 years) and the current rate of data acquisition is ~50 TB per year. This data set is complex and diverse. Making these "Big Data" accessible and attractive to users is our priority. In this presentation, we share our experience as a "Big Data" institution where we deliver simple and multi-dimensional calibrated data cubes to a diverse pool of users. Ocean Networks Canada also conducts extensive user testing. Test results guide future tool design and development of "Big Data" products. We strive to bridge the gap between the raw, archived data and the needs and

Scattering from extended targets in range-dependent fluctuating ocean-waveguides with clutter from theory and experiments.

Science.gov (United States)

Jagannathan, Srinivasan; Küsel, Elizabeth T; Ratilal, Purnima; Makris, Nicholas C

2012-08-01

Bistatic, long-range measurements of acoustic scattered returns from vertically extended, air-filled tubular targets were made during three distinct field experiments in fluctuating continental shelf waveguides. It is shown that Sonar Equation estimates of mean target-scattered intensity lead to large errors, differing by an order of magnitude from both the measurements and waveguide scattering theory. The use of the Ingenito scattering model is also shown to lead to significant errors in estimating mean target-scattered intensity in the field experiments because they were conducted in range-dependent ocean environments with large variations in sound speed structure over the depth of the targets, scenarios that violate basic assumptions of the Ingenito model. Green's theorem based full-field modeling that describes scattering from vertically extended tubular targets in range-dependent ocean waveguides by taking into account nonuniform sound speed structure over the target's depth extent is shown to accurately describe the statistics of the targets' scattered field in all three field experiments. Returns from the man-made targets are also shown to have a very different spectral dependence from the natural target-like clutter of the dominant fish schools observed, suggesting that judicious multi-frequency sensing may often provide a useful means of distinguishing fish from man-made targets.

Ocean circulation generated magnetic signals

DEFF Research Database (Denmark)

Manoj, C.; Kuvshinov, A.; Maus, S.

2006-01-01

Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification...... of ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume...... of the magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

Changes in the concentration of iron in different size fractions during an iron enrichment experiment in the open Southern Ocean

NARCIS (Netherlands)

Nishioka, Jun; Takeda, Shigenobu; Baar, Hein J.W. de; Croot, Peter L.; Boye, Marie; Laan, Patrick; Timmermans, Klaas R.

2005-01-01

An in situ iron enrichment experiment was carried out in the Southern Ocean Polar Frontal Zone and fertilized a patch of water within an eddy of the Antarctic Circumpolar Current (EisenEx, Nov. 2000). During the experiment, a physical speciation technique was used for iron analysis in order to

Gradient flux measurements of sea–air DMS transfer during the Surface Ocean Aerosol Production (SOAP experiment

Directory of Open Access Journals (Sweden)

M. J. Smith

2018-04-01

Full Text Available Direct measurements of marine dimethylsulfide (DMS fluxes are sparse, particularly in the Southern Ocean. The Surface Ocean Aerosol Production (SOAP voyage in February–March 2012 examined the distribution and flux of DMS in a biologically active frontal system in the southwest Pacific Ocean. Three distinct phytoplankton blooms were studied with oceanic DMS concentrations as high as 25 nmol L−1. Measurements of DMS fluxes were made using two independent methods: the eddy covariance (EC technique using atmospheric pressure chemical ionization–mass spectrometry (API-CIMS and the gradient flux (GF technique from an autonomous catamaran platform. Catamaran flux measurements are relatively unaffected by airflow distortion and are made close to the water surface, where gas gradients are largest. Flux measurements were complemented by near-surface hydrographic measurements to elucidate physical factors influencing DMS emission. Individual DMS fluxes derived by EC showed significant scatter and, at times, consistent departures from the Coupled Ocean–Atmosphere Response Experiment gas transfer algorithm (COAREG. A direct comparison between the two flux methods was carried out to separate instrumental effects from environmental effects and showed good agreement with a regression slope of 0.96 (r2 = 0.89. A period of abnormal downward atmospheric heat flux enhanced near-surface ocean stratification and reduced turbulent exchange, during which GF and EC transfer velocities showed good agreement but modelled COAREG values were significantly higher. The transfer velocity derived from near-surface ocean turbulence measurements on a spar buoy compared well with the COAREG model in general but showed less variation. This first direct comparison between EC and GF fluxes of DMS provides confidence in compilation of flux estimates from both techniques, as well as in the stable periods when the observations are not well predicted by the COAREG

Mismo field experiment in the equatorial Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Masumoto, Y.; Kuroda, Y.; Katsumata, M.; Mizuno, K.; Takayabu, Y.N.; Yoshizaki, M.; Shareef, A.; Fujiyoshi, Y.; McPhaden, M.J.; Murty, V.S.N.; Shirooka, R; Yasunaga, K.; Yamada, H.; Sato, N.; Ushiyama, T.; Moteki, Q.; Seiki, A.; Fujita, M.; Ando, K.; Hase, H.; Ueki, I; Horii, T.; Yokoyama, C.; Miyakawa, T.

MISMO FIELD EXPERIMENT IN THE EQUATORIAL INDIAN OCEAN * b y Ku n i o yo n e y a m a , yu K i o ma s u m o t o , yo s h i f u m i Ku r o d a , ma s a K i Ka t s u m a t a , Ke i s u K e mi z u n o , yu K a r i n. ta K a y a b u , ma s a n o r i... yo s h i z a K i , al i sh a r e e f, ya s u s h i fu j i y o s h i , mi c h a e l j. mcPh a d e n , V. s. n. mu r t y , ry u i c h i sh i r o o K a , Ka z u a K i ya s u n a g a , hi r o y u K i ya m a d a , na o K i sa t o , to m o K i us...

The Continuation of Cloud Statistics for NASA Climate Change Studies

Science.gov (United States)

Wylie, Donald P.

2001-01-01

The weather systems, cyclones, and anticyclones, along with air trajectories and cloud forms, are compared to past studies of the Arctic to assess compatibility of the four month study of the Arctic Cloud Experiment flights of the First ISCCP Regional Experiment (FIRE/ACE) with past climatologies. The frequency and movement of cyclones (lows) and anticyclones (highs) followed the general eastward and northeastward directions indicated by past studies. Most cyclones (lows) came from eastern Siberia and the Bering Sea to the south and moved north across the Bering Straight or Alaska into the Arctic Ocean. They generally weakened in central pressure as they moved poleward. Anticyclones (highs) were most common in the eastern Beaufort Sea near Canada in June and July as predicted from previous studies. However, many cyclones and anticyclones moved in westward directions which is rare in other latitudes. Erratic changes in shape and intensity on a daily basis also were observed. The National Center for Environmental Prediction (NCEP) analysis generally reflected the Surface Heat Budget in the Arctic (SHEBA) Ship World Meteorological Organization (WMO) observations which it used. However, NCEP temperatures were biased warm by 1.0 to 1.5 C in April and early May. In July when the surface temperature were at the freezing/thawing point, the NCEP analysis changed to a cold bias of -1.0 C. Dew points had smaller biases except for July where they were biased cold by -1.4 C. Wind speeds had a -2 m/s low bias for the six windiest days. Surface barometric pressures had consistently low biases from -1.2 to -2.8 hPa in all four months. Air parcel historical trajectories were mainly from the south or from local anticyclonic gyres in the Beaufort Sea. Most air came to the SHEBA Ship from the north Pacific Ocean or from Alaska and Canada and occasionally from eastern Siberia. Very few trajectories traced back across the pole to Europe and Central Asia. Cloud cover was high, as

Shifting the Perspective: Artists in the Ocean

Science.gov (United States)

Van Dover, C. L.

2014-12-01

The deep ocean is to most of us a place unknown. Few of us experience the sea far from shore, fewer still dive to the seafloor at great depths. When scientists report on the outcome of deep-ocean exploration, their technical prose captures facts and insights, but fails to capture the emotional power of place and process. Through batik, watercolor illustrations, music, digital art, cartoon, and experimental video, six artists have created a portfolio of work that communicates the human experience of the deep ocean.

Measuring Ocean Literacy: What teens understand about the ocean using the Survey of Ocean Literacy and Engagement (SOLE)

Science.gov (United States)

Greely, T. M.; Lodge, A.

2009-12-01

attitudes significantly contributed to ocean literacy. Teens demonstrated a 2-32% increase in content knowledge following the OCG learning experience. The most significant content gains correlated with ocean literacy Essential Principles 1, 2 and 5. Analysis of environmental reasoning patterns revealed that biocentric reasoning (71%) was most important to teens in solving ocean dilemmas. Further, teens reasoning about challenging ocean dilemmas were capable of supporting a position, counter-argument, rebuttal, and accurately use scientific information. Findings provide empirical evidence that connects field studies with ocean literacy. Current guidelines for ocean literacy address cognitive understanding but lack multimodality. The need for ocean literacy that goes beyond content to include reasoning and actions is relevant towards preparing students, teachers and citizens to regularly contribute to decisions about ocean issues and undertake actions as consumer, citizen or steward. This research supports the use of socioscientific issues and stewardship to advance ‘functional’ ocean literacy.

ExplorOcean H2O SOS: Help Heal the Ocean-Student Operated Solutions: Operation Climate Change

Science.gov (United States)

Weiss, N.; Wood, J. H.

2016-12-01

The ExplorOcean H2O SOS: Help Heal the Ocean—Student Operated Solutions: Operation Climate Change, teaches middle and high school students about ocean threats related to climate change through hands-on activities and learning experiences in the field. During each session (in-class or after-school as a club), students build an understanding about how climate change impacts our oceans using resources provided by ExplorOcean (hands-on activities, presentations, multi-media). Through a student leadership model, students present lessons to each other, interweaving a deep learning of science, 21st century technology, communication skills, and leadership. After participating in learning experiences and activities related to 6 key climate change concepts: 1) Introduction to climate change, 2) Increased sea temperatures, 3) Ocean acidification, 4) Sea level rise, 5) Feedback mechanisms, and 6) Innovative solutions. H2O SOS- Operation Climate change participants select one focus issue and use it to design a multi-pronged campaign to increase awareness about this issue in their local community. The campaign includes social media, an interactive activity, and a visual component. All participating clubs that meet participation and action goals earn a field trip to ExplorOcean where they dive deeper into their selected issue through hands-on activities, real-world investigations, and interviews or presentations with experts. In addition to self-selected opportunities to showcase their focus issue, teams will participate in one of several key events identified by ExplorOcean, including ExplorOcean's annual World Oceans Day Expo.

Can trans-generational experiments be used to enhance species resilience to ocean warming and acidification?

Science.gov (United States)

Chakravarti, Leela J; Jarrold, Michael D; Gibbin, Emma M; Christen, Felix; Massamba-N'Siala, Gloria; Blier, Pierre U; Calosi, Piero

2016-10-01

Human-assisted, trans-generational exposure to ocean warming and acidification has been proposed as a conservation and/or restoration tool to produce resilient offspring. To improve our understanding of the need for and the efficacy of this approach, we characterized life-history and physiological responses in offspring of the marine polychaete Ophryotrocha labronica exposed to predicted ocean warming (OW: + 3°C), ocean acidification (OA: pH -0.5) and their combination (OWA: + 3°C, pH -0.5), following the exposure of their parents to either control conditions ( within-generational exposure ) or the same conditions ( trans-generational exposure ). Trans-generational exposure to OW fully alleviated the negative effects of within-generational exposure to OW on fecundity and egg volume and was accompanied by increased metabolic activity. While within-generational exposure to OA reduced juvenile growth rates and egg volume, trans-generational exposure alleviated the former but could not restore the latter. Surprisingly, exposure to OWA had no negative impacts within- or trans-generationally. Our results highlight the potential for trans-generational laboratory experiments in producing offspring that are resilient to OW and OA. However, trans-generational exposure does not always appear to improve traits and therefore may not be a universally useful tool for all species in the face of global change.

Airborne Ocean Color Imager Experiment Data 1988 - 1991

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic and fisheries data were collected during 1988 through 1991 through a multiagency research project to develop a remote sensing system to provide near...

Role of tropical Indian and Atlantic Oceans variability on ENSO

Science.gov (United States)

Prodhomme, Chloé; Terray, Pascal; Masson, Sebastien; Boschat, Ghyslaine

2014-05-01

There are strong evidences of an interaction between tropical Indian, Atlantic and Pacific Oceans. Nevertheless, these interactions remain deeply controversial. While some authors claim the tropical Indian and Atlantic oceans only play a passive role with respect to ENSO, others suggest a driving role for these two basins on ENSO. The mecanisms underlying these relations are not fully understood and, in the Indian Ocean, the possible role of both modes of tropical variability (the Indian Ocean Dipole (IOD) and the Indian Ocean Basin mode (IOB)) remain unclear. To better quantify and understand how the variability of the tropical Indian and Atlantic Oceans impact ENSO variability, we performed two sensitivity experiments using the SINTEX-F2 coupled model. For each experiment, we suppressed the variability of SST and the air-sea coupling in either the tropical Indian Ocean or tropical Atlantic Ocean by applying a strong nudging of the SST to the observed SST climatology. In both experiments, the ENSO periodicity increases. In the Atlantic experiment, our understanding of this increased periodicity is drastically limited by the strongly biased mean state in this region. Conversely, in the Indian Ocean experiment, the increase of ENSO periodicity is related to the absence of the IOB following the El Niño peak, which leads to a decrease of westerly winds in the western Pacific during late winter and spring after the peak. These weaker westerlies hinders the transition to a La Niña phase and thus increase the duration and periodicity of the event.

Impact into the earth's ocean floor - Preliminary experiments, a planetary model, and possibilities for detection

Science.gov (United States)

Mckinnon, W. B.

1982-01-01

Impact processes and plate tectonics are invoked in an experimental study of craters larger than 100 km in diameter on the ocean floor. Although the results obtained from 22-caliber (383 m/sec) ammunition experiments using dense, saturated sand as a target medium cannot be directly scaled to large events, the phenomenology exhibited is that expected of actual craters on the ocean floor: steep, mixed ejecta plume, gravitational adjustment of the crater to form a shallow basin, and extensive reworking of the ejecta, rim, and floor materials by violent collapse of the transient water cavity. Excavation into the mantle is predicted, although asthenospheric influence on outer ring formation is not. The clearest geophysical signature of such a crater is not topography; detection should instead be based on gravity and geoid anomalies due to uplift of the Moho, magnetic anomalies, and seismic resolution of the Moho uplift and crater formation fault planes.

The effects of ocean acidification on hemocyte of crab species in Alaska from laboratory experiment studies from 2011-07-01 to 2013-07-06 (NODC Accession 0123400)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of ocean acidification on hemocyte of crab species in Alaska....

Application of the Convolution Formalism to the Ocean Tide Potential: Results from the Gravity and Recovery and Climate Experiment (GRACE)

Science.gov (United States)

Desai, S. D.; Yuan, D. -N.

2006-01-01

A computationally efficient approach to reducing omission errors in ocean tide potential models is derived and evaluated using data from the Gravity Recovery and Climate Experiment (GRACE) mission. Ocean tide height models are usually explicitly available at a few frequencies, and a smooth unit response is assumed to infer the response across the tidal spectrum. The convolution formalism of Munk and Cartwright (1966) models this response function with a Fourier series. This allows the total ocean tide height, and therefore the total ocean tide potential, to be modeled as a weighted sum of past, present, and future values of the tide-generating potential. Previous applications of the convolution formalism have usually been limited to tide height models, but we extend it to ocean tide potential models. We use luni-solar ephemerides to derive the required tide-generating potential so that the complete spectrum of the ocean tide potential is efficiently represented. In contrast, the traditionally adopted harmonic model of the ocean tide potential requires the explicit sum of the contributions from individual tidal frequencies. It is therefore subject to omission errors from neglected frequencies and is computationally more intensive. Intersatellite range rate data from the GRACE mission are used to compare convolution and harmonic models of the ocean tide potential. The monthly range rate residual variance is smaller by 4-5%, and the daily residual variance is smaller by as much as 15% when using the convolution model than when using a harmonic model that is defined by twice the number of parameters.

The Ocean: Our Future

Science.gov (United States)

Independent World Commission On The Oceans; Soares, Mario

1998-09-01

The Ocean, Our Future is the official report of the Independent World Commission on the Oceans, chaired by Mário Soares, former President of Portugal. Its aim is to summarize the very real problems affecting the ocean and its future management, and to provide imaginative solutions to these various and interlocking problems. The oceans have traditionally been taken for granted as a source of wealth, opportunity and abundance. Our growing understanding of the oceans has fundamentally changed this perception. We now know that in some areas, abundance is giving way to real scarcity, resulting in severe conflicts. Territorial disputes that threaten peace and security, disruptions to global climate, overfishing, habitat destruction, species extinction, indiscriminate trawling, pollution, the dumping of hazardous and toxic wastes, piracy, terrorism, illegal trafficking and the destruction of coastal communities are among the problems that today form an integral part of the unfolding drama of the oceans. Based on the deliberations, experience and input of more than 100 specialists from around the world, this timely volume provides a powerful overview of the state of our water world.

Temperature, salinity, conductivity, and other measurements collected in the Northern Ocean as part of the Arctic Experiment in 1994 (NODC Accession 0002728)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Investigation of thermohaline circulation in Nordic Seas, hydrography and pathways of Atlantic water summer Arctic experiments

Final Progress Report: Direct Experiments on the Ocean Disposal of Fossil Fuel CO2.

Energy Technology Data Exchange (ETDEWEB)

James P. Barry; Peter G. Brewer

2004-05-25

OAK-B135 This report summarizes activities and results of investigations of the potential environmental consequences of direct injection of carbon dioxide into the deep-sea as a carbon sequestration method. Results of field experiments using small scale in situ releases of liquid CO2 are described in detail. The major conclusions of these experiments are that mortality rates of deep sea biota will vary depending on the concentrations of CO2 in deep ocean waters that result from a carbon sequestration project. Large changes in seawater acidity and carbon dioxide content near CO2 release sites will likely cause significant harm to deep-sea marine life. Smaller changes in seawater chemistry at greater distances from release sites will be less harmful, but may result in significant ecosystem changes.

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

Science.gov (United States)

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

2016-12-01

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

Boundary Conditions, Data Assimilation, and Predictability in Coastal Ocean Models

National Research Council Canada - National Science Library

Samelson, Roger M; Allen, John S; Egbert, Gary D; Kindle, John C; Snyder, Chris

2007-01-01

...: The specific objectives of this research are to determine the impact on coastal ocean circulation models of open ocean boundary conditions from Global Ocean Data Assimilation Experiment (GODAE...

Effects of ocean acidification on shell condition and survival of Puget Sound pteropods from laboratory experiment studies from 2012-05-10 to 2012-07-12 (NODC Accession 0125008)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of ocean acidification on shell condition and survival of Puget...

Chaotic advection in the ocean

Energy Technology Data Exchange (ETDEWEB)

Koshel' , Konstantin V; Prants, Sergei V [V.I. Il' ichev Pacific Oceanological Institute, Far-Eastern Division of the Russian Academy of Sciences, Vladivostok (Russian Federation)

2006-11-30

The problem of chaotic advection of passive scalars in the ocean and its topological, dynamical, and fractal properties are considered from the standpoint of the theory of dynamical systems. Analytic and numerical results on Lagrangian transport and mixing in kinematic and dynamic chaotic advection models are described for meandering jet currents, topographical eddies in a barotropic ocean, and a two-layer baroclinic ocean. Laboratory experiments on hydrodynamic flows in rotating tanks as an imitation of geophysical chaotic advection are described. Perspectives of a dynamical system approach in physical oceanography are discussed. (reviews of topical problems)

Tracking the India-Arabia Transform Plate Boundary during Paleogene Times.

Science.gov (United States)

Rodriguez, M.; Huchon, P.; Chamot-Rooke, N. R. A.; Fournier, M.; Delescluse, M.

2014-12-01

The Zagros and Himalaya mountain belts are the most prominent reliefs built by continental collision. They respectively result from Arabia and India collision with Eurasia. Convergence motions at mountain belts induced most of plate reorganization events in the Indian Ocean during the Cenozoic. Although critical for paleogeographic reconstructions, the way relative motion between Arabia and India was accommodated prior to the formation of the Sheba ridge in the Gulf of Aden remains poorly understood. The India-Arabia plate-boundary belongs to the category of long-lived (~90-Ma) oceanic transform faults, thus providing a good case study to investigate the role of major kinematic events over the structural evolution of a long-lived transform system. A seismic dataset crossing the Owen Fracture Zone, the Owen Basin, and the Oman Margin was acquired to track the past locations of the India-Arabia plate boundary. We highlight the composite age of the Owen Basin basement, made of Paleocene oceanic crust drilled on its eastern part, and composed of pre-Maastrichtian continental crust overlaid by Early Paleocene ophiolites on its western side. A major transform fault system crossing the Owen Basin juxtaposed these two slivers of lithosphere of different ages, and controlled the uplift of marginal ridges along the Oman Margin. This transform system deactivated ~40 Ma ago, coeval with the onset of ultra-slow spreading at the Carlsberg Ridge. The transform boundary then jumped to the edge of the present-day Owen Ridge during the Late Eocene-Oligocene period, before seafloor spreading began at the Sheba Ridge. This migration of the plate boundary involved the transfer of a part of the Indian oceanic lithosphere accreted at the Carlsberg Ridge to the Arabian plate. The episode of plate transfer at the India-Arabia plate boundary during the Late Eocene-Oligocene interval is synchronous with a global plate reorganization event corresponding to geological events at the Zagros and

Downscaling Ocean Conditions: Initial Results using a Quasigeostrophic and Realistic Ocean Model

Science.gov (United States)

Katavouta, Anna; Thompson, Keith

2014-05-01

Previous theoretical work (Henshaw et al, 2003) has shown that the small-scale modes of variability of solutions of the unforced, incompressible Navier-Stokes equation, and Burgers' equation, can be reconstructed with surprisingly high accuracy from the time history of a few of the large-scale modes. Motivated by this theoretical work we first describe a straightforward method for assimilating information on the large scales in order to recover the small scale oceanic variability. The method is based on nudging in specific wavebands and frequencies and is similar to the so-called spectral nudging method that has been used successfully for atmospheric downscaling with limited area models (e.g. von Storch et al., 2000). The validity of the method is tested using a quasigestrophic model configured to simulate a double ocean gyre separated by an unstable mid-ocean jet. It is shown that important features of the ocean circulation including the position of the meandering mid-ocean jet and associated pinch-off eddies can indeed be recovered from the time history of a small number of large-scales modes. The benefit of assimilating additional time series of observations from a limited number of locations, that alone are too sparse to significantly improve the recovery of the small scales using traditional assimilation techniques, is also demonstrated using several twin experiments. The final part of the study outlines the application of the approach using a realistic high resolution (1/36 degree) model, based on the NEMO (Nucleus for European Modelling of the Ocean) modeling framework, configured for the Scotian Shelf of the east coast of Canada. The large scale conditions used in this application are obtained from the HYCOM (HYbrid Coordinate Ocean Model) + NCODA (Navy Coupled Ocean Data Assimilation) global 1/12 degree analysis product. Henshaw, W., Kreiss, H.-O., Ystrom, J., 2003. Numerical experiments on the interaction between the larger- and the small-scale motion of

Oceanic diffusion in the coastal area

International Nuclear Information System (INIS)

Rukuda, Masaaki

1980-03-01

Described in this paper is the eddy diffusion in the area off Tokai Village investigated by means of dye diffusion experiment and of oceanic observation. In order to assess the oceanic diffusion in coastal areas, improved methods effective in complex field were developed. The oceanic diffusion was separated in two groups, horizontal and vertical diffusion respectively. Both these diffusions are combined and their analysis together is difficult. The oceanic diffusion is thus considered separately. Instantaneous point release is the basis of horizontal diffusion analysis. Continuous release is then the overlap of numerous instantaneous releases. It was shown that the diffusion parameters derived from the results of diffusion experiment or oceanic observation vary widely with time and place and with sea conditions. A simple diffusion equation was developed from the equation of continuity. The results were in good agreement with seasonal mean horizontal distribution of river water in the sea area. The vertical observation in diffusion experiment is difficult and the vertical structure of oceanic condition is complex, so that the research on vertical diffusion generally is not advanced yet. With river water as the tracer, a method of estimating vertical diffusion parameters with a Gaussian model or one-dimensional model was developed. The vertical diffusion near sea bottom was numerically analized with suspended particles in seawater as the tracer. Diffusion was computed for each particle size, and by summing up the vertical distribution of beam attenuation coefficient was estimated. By comparing the results of estimation and those of observation the vertical diffusivity and the particle size distribution at sea bottom could be estimated. (author)

The Experience of Barometric Drifter Application for Investigating the World Ocean Arctic Region

Directory of Open Access Journals (Sweden)

S.V. Motyzhev

2016-08-01

Full Text Available Efficiency of the problem solution to create a regionally-oriented data computing system for marine dynamics and ecosystem evolution modeling and forecasting (that should be capable for providing reliable information for managerial decision making, justifying future economic projects and adjusting the existing ones depends on development level of observational systems, environmental evolution, mathematical models and techniques for observational data assimilation. The analysis of the system as an observational segment of modern geo-informational technology allows us to draw a conclusion that the system of drifter observations is one of the most effective ones nowadays. Surface drifter network, continuously operating in the World Ocean, provides systematic operational data on the surface water circulation, thermal processes in the upper ocean and air pressure. Drifter data, acquired over the past 15 years, allowed one to improve and even change the existing concepts of patterns and mechanisms of regional climatic trend and hydrometeorological anomaly formation under effect of global processes in the Ocean – Atmosphere model (in the high latitudes as well. In the present paper the principle results of the analysis of expediency and feasibility of drifting systematic operative pressure field monitoring establishment in the near-surface atmosphere layer over the Arctic Ocean and the seas of the Russian Federation Arctic Zone have been considered. More than 30 drifters of BTC60/GPS/ice type, whose summarized lifetime as for June 2015 exceeded 6500 days, were deployed in the Arctic in 2012–2015. According to data acquired from the drifters, more than 155 000 air pressure readings were received. The most intensive drifter observations were carried out in two regions: in the Beaufort Sea – Canada Basin and in the Central Arctic. The results of experiments revealed that hardware-software solutions implemented in polar modifications of barometric

Comparison of the ocean surface vector winds over the Nordic Seas and their application for ocean modeling

Science.gov (United States)

Dukhovskoy, Dmitry; Bourassa, Mark

2017-04-01

Ocean processes in the Nordic Seas and northern North Atlantic are strongly controlled by air-sea heat and momentum fluxes. The predominantly cyclonic, large-scale atmospheric circulation brings the deep ocean layer up to the surface preconditioning the convective sites in the Nordic Seas for deep convection. In winter, intensive cooling and possibly salt flux from newly formed sea ice erodes the near-surface stratification and the mixed layer merges with the deeper domed layer, exposing the very weakly stratified deep water mass to direct interaction with the atmosphere. Surface wind is one of the atmospheric parameters required for estimating momentum and turbulent heat fluxes to the sea ice and ocean surface. In the ocean models forced by atmospheric analysis, errors in surface wind fields result in errors in air-sea heat and momentum fluxes, water mass formation, ocean circulation, as well as volume and heat transport in the straits. The goal of the study is to assess discrepancies across the wind vector fields from reanalysis data sets and scatterometer-derived gridded products over the Nordic Seas and northern North Atlantic and to demonstrate possible implications of these differences for ocean modeling. The analyzed data sets include the reanalysis data from the National Center for Environmental Prediction Reanalysis 2 (NCEPR2), Climate Forecast System Reanalysis (CFSR), Arctic System Reanalysis (ASR) and satellite wind products Cross-Calibrated Multi-Platform (CCMP) wind product version 1.1 and recently released version 2.0, and Remote Sensing Systems QuikSCAT data. Large-scale and mesoscale characteristics of winds are compared at interannual, seasonal, and synoptic timescales. Numerical sensitivity experiments are conducted with a coupled ice-ocean model forced by different wind fields. The sensitivity experiments demonstrate differences in the net surface heat fluxes during storm events. Next, it is hypothesized that discrepancies in the wind vorticity

The 360 Degree Fulldome Production "Clockwork Ocean"

Science.gov (United States)

Baschek, B.; Heinsohn, R.; Opitz, D.; Fischer, T.; Baschek, T.

2016-02-01

The investigation of submesoscale eddies and fronts is one of the leading oceanographic topics at the Ocean Sciences Meeting 2016. In order to observe these small and short-lived phenomena, planes equipped with high-resolution cameras and fast vessels were deployed during the Submesoscale Experiments (SubEx) leading to some of the first high-resolution observations of these eddies. In a future experiment, a zeppelin will be used the first time in marine sciences. The relevance of submesoscale processes for the oceans and the work of the eddy hunters is described in the fascinating 9-minute long 360 degree fulldome production Clockwork Ocean. The fully animated movie is introduced in this presentation taking the observer from the bioluminescence in the deep ocean to a view of our blue planet from space. The immersive media is used to combine fascination for a yet unknown environment with scientific education of a broad audience. Detailed background information is available at the parallax website www.clockwork-ocean.com. The Film is also available for Virtual Reality glasses and smartphones to reach a broader distribution. A unique Mobile Dome with an area of 70 m² and seats for 40 people is used for science education at events, festivals, for politicians and school classes. The spectators are also invited to participate in the experiments by presenting 360 degree footage of the measurements. The premiere of Clockwork Ocean was in July 2015 in Hamburg, Germany and will be worldwide available in English and German as of fall 2015. Clockwork Ocean is a film of the Helmholtz-Zentrum Geesthacht produced by Daniel Opitz and Ralph Heinsohn.

Investigating the Potential Impact of the Surface Water and Ocean Topography (SWOT) Altimeter on Ocean Mesoscale Prediction

Science.gov (United States)

Carrier, M.; Ngodock, H.; Smith, S. R.; Souopgui, I.

2016-02-01

NASA's Surface Water and Ocean Topography (SWOT) satellite, scheduled for launch in 2020, will provide sea surface height anomaly (SSHA) observations with a wider swath width and higher spatial resolution than current satellite altimeters. It is expected that this will help to further constrain ocean models in terms of the mesoscale circulation. In this work, this expectation is investigated by way of twin data assimilation experiments using the Navy Coastal Ocean Model Four Dimensional Variational (NCOM-4DVAR) data assimilation system using a weak constraint formulation. Here, a nature run is created from which SWOT observations are sampled, as well as along-track SSHA observations from simulated Jason-2 tracks. The simulated SWOT data has appropriate spatial coverage, resolution, and noise characteristics based on an observation-simulator program provided by the SWOT science team. The experiment is run for a three-month period during which the analysis is updated every 24 hours and each analysis is used to initialize a 96 hour forecast. The forecasts in each experiment are compared to the available nature run to determine the impact of the assimilated data. It is demonstrated here that the SWOT observations help to constrain the model mesoscale in a more consistent manner than traditional altimeter observations. The findings of this study suggest that data from SWOT may have a substantial impact on improving the ocean model analysis and forecast of mesoscale features and surface ocean transport.

Impact of Arctic sea-ice retreat on the recent change in cloud-base height during autumn

Science.gov (United States)

Sato, K.; Inoue, J.; Kodama, Y.; Overland, J. E.

2012-12-01

Cloud-base observations over the ice-free Chukchi and Beaufort Seas in autumn were conducted using a shipboard ceilometer and radiosondes during the 1999-2010 cruises of the Japanese R/V Mirai. To understand the recent change in cloud base height over the Arctic Ocean, these cloud-base height data were compared with the observation data under ice-covered situation during SHEBA (the Surface Heat Budget of the Arctic Ocean project in 1998). Our ice-free results showed a 30 % decrease (increase) in the frequency of low clouds with a ceiling below (above) 500 m. Temperature profiles revealed that the boundary layer was well developed over the ice-free ocean in the 2000s, whereas a stable layer dominated during the ice-covered period in 1998. The change in surface boundary conditions likely resulted in the difference in cloud-base height, although it had little impact on air temperatures in the mid- and upper troposphere. Data from the 2010 R/V Mirai cruise were investigated in detail in terms of air-sea temperature difference. This suggests that stratus cloud over the sea ice has been replaced as stratocumulus clouds with low cloud fraction due to the decrease in static stability induced by the sea-ice retreat. The relationship between cloud-base height and air-sea temperature difference (SST-Ts) was analyzed in detail using special section data during 2010 cruise data. Stratus clouds near the sea surface were predominant under a warm advection situation, whereas stratocumulus clouds with a cloud-free layer were significant under a cold advection situation. The threshold temperature difference between sea surface and air temperatures for distinguishing the dominant cloud types was 3 K. Anomalous upward turbulent heat fluxes associated with the sea-ice retreat have likely contributed to warming of the lower troposphere. Frequency distribution of the cloud-base height (km) detected by a ceilometer/lidar (black bars) and radiosondes (gray bars), and profiles of potential

Engaging Ocean Grads As Interdisciplinary Professional Problem Solvers: Why Preparing Our Future Ocean Leaders Means Inspiring Them to Look Beyond Their Academic Learning.

Science.gov (United States)

Good, L. H.; Erickson, A.

2016-02-01

Academic learning and research experiences alone cannot prepare our emerging ocean leaders to take on the challenges facing our oceans. Developing solutions that incorporate environmental and ocean sciences necessitates an interdisciplinary approach, requiring emerging leaders to be able to work in collaborative knowledge to action systems, rather than on micro-discipline islands. Professional and informal learning experiences can enhance graduate marine education by helping learners gain the communication, collaboration, and innovative problem-solving skills necessary for them to interact with peers at the interface of science and policy. These rich experiences can also provide case-based and hands-on opportunities for graduate learners to explore real-world examples of ocean science, policy, and management in action. However, academic programs are often limited in their capacity to offer such experiences as a part of a traditional curriculum. Rather than expecting learners to rely on their academic training, one approach is to encourage and support graduates to seek professional development beyond their university's walls, and think more holistically about their learning as it relates to their career interests. During this session we discuss current thinking around the professional learning needs of emerging ocean leaders, what this means for academic epistemologies, and examine initial evaluation outcomes from activities in our cross-campus consortium model in Monterey Bay, California. This innovative model includes seven regional academic institutions working together to develop an interdisciplinary ocean community and increase access to professional development opportunities to better prepare regional ocean-interested graduate students and early career researchers as future leaders.

Ocean eddies and climate predictability.

Science.gov (United States)

Kirtman, Ben P; Perlin, Natalie; Siqueira, Leo

2017-12-01

A suite of coupled climate model simulations and experiments are used to examine how resolved mesoscale ocean features affect aspects of climate variability, air-sea interactions, and predictability. In combination with control simulations, experiments with the interactive ensemble coupling strategy are used to further amplify the role of the oceanic mesoscale field and the associated air-sea feedbacks and predictability. The basic intent of the interactive ensemble coupling strategy is to reduce the atmospheric noise at the air-sea interface, allowing an assessment of how noise affects the variability, and in this case, it is also used to diagnose predictability from the perspective of signal-to-noise ratios. The climate variability is assessed from the perspective of sea surface temperature (SST) variance ratios, and it is shown that, unsurprisingly, mesoscale variability significantly increases SST variance. Perhaps surprising is the fact that the presence of mesoscale ocean features even further enhances the SST variance in the interactive ensemble simulation beyond what would be expected from simple linear arguments. Changes in the air-sea coupling between simulations are assessed using pointwise convective rainfall-SST and convective rainfall-SST tendency correlations and again emphasize how the oceanic mesoscale alters the local association between convective rainfall and SST. Understanding the possible relationships between the SST-forced signal and the weather noise is critically important in climate predictability. We use the interactive ensemble simulations to diagnose this relationship, and we find that the presence of mesoscale ocean features significantly enhances this link particularly in ocean eddy rich regions. Finally, we use signal-to-noise ratios to show that the ocean mesoscale activity increases model estimated predictability in terms of convective precipitation and atmospheric upper tropospheric circulation.

Influencing a Vision for the Future Ocean

Science.gov (United States)

Macko, S. A.

2017-12-01

The ocean is the major source of nutrition for billions of people, while employing millions of workers, and generating trillions of dollars for the world economy. Clearly, the ocean is central to human well-being. As vast as our ocean and its resources are, they are not infinite. And today the ocean is under tremendous pressure from human activity - including unsustainable and illegal fishing, marine pollution, and climate-related impacts. We have created a special January-term class that offered students exposure to the utilization of the oceans' resources through a mixture of in-class work and field experiences. The course addressed not only fundamentals of marine science, but also legalities and ethics on aspects of culturing and capturing marine animals, with an emphasis on aquaculture and sustainability for wild fisheries. We limited the course to a manageble number (18) with transport in 3 vans, and overnighting at convenient hotels near the sites. Various trips to locations where the ocean is being maricultured and/or marketed allowed students to explore both the extant ocean while complementing class activities with speakers dealing with fishery product distribution and aquaculture with laboratory experiences at UVa. Locations for field trips included the National Aquarium in Baltimore, Washington, Virginia Beach and Baltimore seafood markets, Virginia aquaculture facilities and the Virginia Aquarium in Virginia Beach.

IODP Expedition 301 Installs Three Borehole Crustal Observatories, Prepares for Three-Dimensional, Cross-Hole Experiments in the Northeastern Pacific Ocean

Directory of Open Access Journals (Sweden)

Adam Klaus

2005-09-01

Full Text Available Introduction and Goals The basaltic upper oceanic crust comprises the largestaquifer on Earth, containing a volume of water about equalto that currently stored in ice sheets and glaciers. Annualfluid fluxes through the upper oceanic crust are at leastas large as the global river flux to the ocean. Much of theseafloor is hydrogeologically active, but the majority ofthe fluid flow within oceanic crust occurs on ridge flanks,regions located kilometers or more from active seafloorspreading centers. Fluid circulation in these areas is drivenmainly by lithospheric heat rising from deep within theplate but is influenced by seafloor and basement topography,seismic and tectonic events, and tides.Subseaf loor f luid f low on ridge f lanks inf luences adiverse array of processes and properties, including thethermal state and evolution of oceanic plates, alteration ofthe lithosphere and crustal pore waters, establishment andmaintenance of vast subseaf loor microbial ecosystems,and diagenetic, seismic, and magmatic activity along plateboundaryfaults. Although numerous drilling expeditionsand surface and submersible surveys over the last severaldecades have focused on hydrogeologic phenomena, we stillknow relatively little about driving forces, property distributions,scales of flow, rates of flow, extent of compartmentalizationor isolation of distinct fluid-rock systems, or linksbetween hydrogeologic, geochemical, microbiological, andgeophysical processes. Progress through drilling has beenlimited in the past by the perturbing effects of boreholecreation on subseafloor thermal, pressure, chemical, andbiological conditions. Subseafloor observatories addressthis challenge by allowing the formation to recover fromdrilling perturbations, and also allow scientists to runpassive and active experiments for years to decades.IODP Expedition 301 was part of a multi-disciplinaryprogram designed to evaluate the formation-scale hydrogeologicproperties within oceanic crust

A simple model of the effect of ocean ventilation on ocean heat uptake

Energy Technology Data Exchange (ETDEWEB)

Nadiga, Balasubramanya T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Urban, Nathan Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-01-27

Presentation includes slides on Earth System Models vs. Simple Climate Models; A Popular SCM: Energy Balance Model of Anomalies; On calibrating against one ESM experiment, the SCM correctly captures that ESM's surface warming response with other forcings; Multi-Model Analysis: Multiple ESMs, Single SCM; Posterior Distributions of ECS; However In Excess of 90% of TOA Energy Imbalance is Sequestered in the World Oceans; Heat Storage in the Two Layer Model; Heat Storage in the Two Layer Model; Including TOA Rad. Imbalance and Ocean Heat in Calibration Improves Repr., but Significant Errors Persist; Improved Vertical Resolution Does Not Fix Problem; A Series of Expts. Confirms That Anomaly-Diffusing Models Cannot Properly Represent Ocean Heat Uptake; Physics of the Thermocline; Outcropping Isopycnals and Horizontally-Averaged Layers; Local interactions between outcropping isopycnals leads to non-local interactions between horizontally-averaged layers; Both Surface Warming and Ocean Heat are Well Represented With Just 4 Layers; A Series of Expts. Confirms That When Non-Local Interactions are Allowed, the SCMs Can Represent Both Surface Warming and Ocean Heat Uptake; and Summary and Conclusions.

Anthropogenic CO2 in the ocean

Directory of Open Access Journals (Sweden)

Tsung-Hung Peng

2005-06-01

Full Text Available The focus of this review article is on the anthropogenic CO2 taken up by the ocean. There are several methods of identifying the anthropogenic CO2 signal and quantifying its inventory in the ocean. The ?C* method is most frequently used to estimate the global distribution of anthropogenic CO2 in the ocean. Results based on analysis of the dataset obtained from the comprehensive surveys of inorganic carbon distribution in the world oceans in the 1990s are given. These surveys were jointly conducted during the World Ocean Circulation Experiment (WOCE and the Joint Global Ocean Flux Study (JGOFS. This data set consists of 9618 hydrographic stations from a total of 95 cruises, which represents the most accurate and comprehensive view of the distribution of inorganic carbon in the global ocean available today. The increase of anthropogenic CO2 in the ocean during the past few decades is also evaluated using direct comparison of results from repeat surveys and using statistical method of Multi-parameter Linear Regression (MLR. The impact of increasing oceanic anthropogenic CO2 on the calcium carbonate system in the ocean is reviewed briefly as well. Extensive studies of CaCO3 dissolution as a result of increasing anthropogenic CO2 in the ocean have revealed several distinct oceanic regions where the CaCO3 undersaturation zone has expanded.

Variability of the carbonate chemistry in a shallow, seagrass-dominated ecosystem: implications for ocean acidification experiments

Science.gov (United States)

Challener, Roberta; Robbins, Lisa L.; Mcclintock, James B.

2016-01-01

Open ocean observations have shown that increasing levels of anthropogenically derived atmospheric CO2 are causing acidification of the world's oceans. Yet little is known about coastal acidification and studies are just beginning to characterise the carbonate chemistry of shallow, nearshore zones where many ecologically and economically important organisms occur. We characterised the carbonate chemistry of seawater within an area dominated by seagrass beds (Saint Joseph Bay, Florida) to determine the extent of variation in pH and pCO2 over monthly and daily timescales. Distinct diel and seasonal fluctuations were observed at daily and monthly timescales respectively, indicating the influence of photosynthetic and respiratory processes on the local carbonate chemistry. Over the course of a year, the range in monthly values of pH (7.36-8.28), aragonite saturation state (0.65-5.63), and calculated pCO2 (195-2537 μatm) were significant. When sampled on a daily basis the range in pH (7.70-8.06), aragonite saturation state (1.86-3.85), and calculated pCO2 (379-1019 μatm) also exhibited significant range and indicated variation between timescales. The results of this study have significant implications for the design of ocean acidification experiments where nearshore species are utilised and indicate that coastal species are experiencing far greater fluctuations in carbonate chemistry than previously thought.

New perspectives in ocean acidification research: editor's introduction to the special feature on ocean acidification.

Science.gov (United States)

Munday, Philip L

2017-09-01

Ocean acidification, caused by the uptake of additional carbon dioxide (CO 2 ) from the atmosphere, will have far-reaching impacts on marine ecosystems (Gattuso & Hansson 2011 Ocean acidification Oxford University Press). The predicted changes in ocean chemistry will affect whole biological communities and will occur within the context of global warming and other anthropogenic stressors; yet much of the biological research conducted to date has tested the short-term responses of single species to ocean acidification conditions alone. While an important starting point, these studies may have limited predictive power because they do not account for possible interactive effects of multiple climate change drivers or for ecological interactions with other species. Furthermore, few studies have considered variation in responses among populations or the evolutionary potential within populations. Therefore, our knowledge about the potential for marine organisms to adapt to ocean acidification is extremely limited. In 2015, two of the pioneers in the field, Ulf Riebesell and Jean-Pierre Gattuso, noted that to move forward as a field of study, future research needed to address critical knowledge gaps in three major areas: (i) multiple environmental drivers, (ii) ecological interactions and (iii) acclimation and adaptation (Riebesell and Gattuso 2015 Nat. Clim. Change 5 , 12-14 (doi:10.1038/nclimate2456)). In May 2016, more than 350 researchers, students and stakeholders met at the 4th International Symposium on the Ocean in a High-CO 2 World in Hobart, Tasmania, to discuss the latest advances in understanding ocean acidification and its biological consequences. Many of the papers presented at the symposium reflected this shift in focus from short-term, single species and single stressor experiments towards multi-stressor and multispecies experiments that address knowledge gaps about the ecological impacts of ocean acidification on marine communities. The nine papers in this

Effects of ocean acidification on hatch size and larval growth of walleye pollock (Theragra chalcogramma) from laboratory experiment studies from 2010-03-01 to 2011-05-31 (NODC Accession 0125007)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of ocean acidification on hatch size and larval growth of...

Southern Ocean carbon-wind stress feedback

Science.gov (United States)

Bronselaer, Ben; Zanna, Laure; Munday, David R.; Lowe, Jason

2018-02-01

The Southern Ocean is the largest sink of anthropogenic carbon in the present-day climate. Here, Southern Ocean pCO2 and its dependence on wind forcing are investigated using an equilibrium mixed layer carbon budget. This budget is used to derive an expression for Southern Ocean pCO2 sensitivity to wind stress. Southern Ocean pCO2 is found to vary as the square root of area-mean wind stress, arising from the dominance of vertical mixing over other processes such as lateral Ekman transport. The expression for pCO2 is validated using idealised coarse-resolution ocean numerical experiments. Additionally, we show that increased (decreased) stratification through surface warming reduces (increases) the sensitivity of the Southern Ocean pCO2 to wind stress. The scaling is then used to estimate the wind-stress induced changes of atmospheric pCO_2 in CMIP5 models using only a handful of parameters. The scaling is further used to model the anthropogenic carbon sink, showing a long-term reversal of the Southern Ocean sink for large wind stress strength.

Using ocean bottom pressure from the gravity recovery and climate experiment (GRACE) to estimate transport variability in the southern Indian Ocean

Science.gov (United States)

Makowski, Jessica K.; Chambers, Don P.; Bonin, Jennifer A.

2015-06-01

Previous studies have suggested that ocean bottom pressure (OBP) from the Gravity Recovery and Climate Experiment (GRACE) can be used to measure the depth-averaged, or barotropic, transport variability of the Antarctic Circumpolar Current (ACC). Here, we use GRACE OBP observations to calculate transport variability in a region of the southern Indian Ocean encompassing the major fronts of the ACC. We use a statistical analysis of a simulated GRACE-like data set to determine the uncertainty of the estimated transport for the 2003.0-2013.0 time period. We find that when the transport is averaged over 60° of longitude, the uncertainty (one standard error) is close to 1 Sv (1 Sv = 106 m3 s-1) for low-pass filtered transport, which is significantly smaller than the signal and lower than previous studies have found. The interannual variability is correlated with the Southern Annual mode (SAM) (0.61), but more highly correlated with circumpolar zonally averaged winds between 45°S and 65°S (0.88). GRACE transport reflects significant changes in transport between 2007 and 2009 that is observed in the zonal wind variations but not in the SAM index. We also find a statistically significant trend in transport (-1.0 ± 0.4 Sv yr-1, 90% confidence) that is correlated with a local deceleration in zonal winds related to an asymmetry in the SAM on multidecadal periods.

Alkaline phosphatase activity in the subtropical ocean: insights from nutrient, dust and trace metal addition experiments

Directory of Open Access Journals (Sweden)

Claire eMahaffey

2014-12-01

Full Text Available Phosphorus is an essential nutrient for all life on earth. In the ocean, the most bioavailable form of phosphorus is inorganic phosphate, but in the extensive subtropical gyres, phosphate concentrations can be chronically low and limit primary productivity and nitrogen fixation. In these regions, organisms produce hydrolytic enzymes, such as alkaline phosphatase (AP, that enable them to utilize the more replete dissolved organic phosphorus (DOP pool to meet their cellular phosphorus demands. In this study, we synthesized data from 14 published studies and present our own findings from two research cruises (D326 and D361 in the eastern subtropical Atlantic to explore the relationship between AP activity (APA and nutrients, Saharan dust and trace metals. We found that below a threshold phosphate concentration of ~ 30 nM, APA increased with an inverse hyperbolic relationship with phosphate concentration. Meanwhile, DOP concentrations decreased with enhanced APA, indicating utilization of the DOP pool. We found APA rates were significantly higher in the subtropical Atlantic compared to the subtropical Pacific Ocean, even over the same low phosphate concentration range (0 to 50 nM. While the phosphate concentration may have a first order control on the APA rates, we speculate that other factors influence this basin scale contrast. Using bioassay experiments, we show that the addition of Saharan dust and zinc significantly increased the rate of APA. To our knowledge, our results are the first direct field-based evidence that APA is limited by zinc in the subtropical ocean. Further work is required to explore the relationship between trace metals such as iron and zinc, which are co-factors of phosphohydrolytic enzymes, specifically PhoX and PhoA, respectively, and APA in the ocean.

Ocean Acidification | Smithsonian Ocean Portal

Science.gov (United States)

Natural History Blog For Educators At The Museum Media Archive Ocean Life & Ecosystems Mammals Sharks Mangroves Poles Census of Marine Life Planet Ocean Tides & Currents Waves & Storms The Seafloor ocean is affected. Such a relatively quick change in ocean chemistry doesn't give marine life, which

Coastal Zone Color Scanner (CZCS): Imagery of near-surface phytoplankton pigment concentrations from the first coastal ocean dynamics experiment (CODE-1), March - July 1981

Science.gov (United States)

Abbott, M. R.; Zion, P. M.

1984-01-01

As part of the first Coastal Ocean Dynamics Experiment, images of ocean color were collected from late March until late July, 1981, by the Coastal Zone Color Scanner aboard Nimbus-7. Images that had sufficient cloud-free area to be of interest were processed to yield near-surface phytoplankton pigment concentrations. These images were then remapped to a fixed equal-area grid. This report contains photographs of the digital images and a brief description of the processing methods.

Tide Gauge Records Reveal Improved Processing of Gravity Recovery and Climate Experiment Time-Variable Mass Solutions over the Coastal Ocean

Science.gov (United States)

Piecuch, Christopher G.; Landerer, Felix W.; Ponte, Rui M.

2018-05-01

Monthly ocean bottom pressure solutions from the Gravity Recovery and Climate Experiment (GRACE), derived using surface spherical cap mass concentration (MC) blocks and spherical harmonics (SH) basis functions, are compared to tide gauge (TG) monthly averaged sea level data over 2003-2015 to evaluate improved gravimetric data processing methods near the coast. MC solutions can explain ≳ 42% of the monthly variance in TG time series over broad shelf regions and in semi-enclosed marginal seas. MC solutions also generally explain ˜5-32 % more TG data variance than SH estimates. Applying a coastline resolution improvement algorithm in the GRACE data processing leads to ˜ 31% more variance in TG records explained by the MC solution on average compared to not using this algorithm. Synthetic observations sampled from an ocean general circulation model exhibit similar patterns of correspondence between modeled TG and MC time series and differences between MC and SH time series in terms of their relationship with TG time series, suggesting that observational results here are generally consistent with expectations from ocean dynamics. This work demonstrates the improved quality of recent MC solutions compared to earlier SH estimates over the coastal ocean, and suggests that the MC solutions could be a useful tool for understanding contemporary coastal sea level variability and change.

Ocean acidification in a geoengineering context

Science.gov (United States)

Williamson, Phillip; Turley, Carol

2012-01-01

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

Laboratory Models of Ocean Circulation

National Research Council Canada - National Science Library

Whitehead, John

1997-01-01

...). The subsequent studies were then split into two separate experiments involving convection in the two types of configurations which are likely to produce the very coldest water in the oceans, one...

Profile and bottle data collected on the RV Melville (cruise Vancouver 06) from the Agulhas-South Atlantic Thermohaline Transport Experiment (ASTTEX) in the Atlantic Ocean from 20030102 to 20030115 (NODC Accession 0074001)

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National Oceanic and Atmospheric Administration, Department of Commerce — Introduction: The Agulhas-South Atlantic Thermohaline Experiment (ASTTEX) examined the fluxes of heat, salt and mass entering the South Atlantic ocean via the...

Downscaling the climate change for oceans around Australia

Directory of Open Access Journals (Sweden)

M. A. Chamberlain

2012-09-01

Full Text Available At present, global climate models used to project changes in climate poorly resolve mesoscale ocean features such as boundary currents and eddies. These missing features may be important to realistically project the marine impacts of climate change. Here we present a framework for dynamically downscaling coarse climate change projections utilising a near-global ocean model that resolves these features in the Australasian region, with coarser resolution elsewhere.

A time-slice projection for a 2060s ocean was obtained by adding climate change anomalies to initial conditions and surface fluxes of a near-global eddy-resolving ocean model. Climate change anomalies are derived from the differences between present and projected climates from a coarse global climate model. These anomalies are added to observed fields, thereby reducing the effect of model bias from the climate model.

The downscaling model used here is ocean-only and does not include the effects that changes in the ocean state will have on the atmosphere and air–sea fluxes. We use restoring of the sea surface temperature and salinity to approximate real-ocean feedback on heat flux and to keep the salinity stable. Extra experiments with different feedback parameterisations are run to test the sensitivity of the projection. Consistent spatial differences emerge in sea surface temperature, salinity, stratification and transport between the downscaled projections and those of the climate model. Also, the spatial differences become established rapidly (< 3 yr, indicating the importance of mesoscale resolution. However, the differences in the magnitude of the difference between experiments show that feedback of the ocean onto the air–sea fluxes is still important in determining the state of the ocean in these projections.

Until such a time when it is feasible to regularly run a global climate model with eddy resolution, our framework for ocean climate change

Ocean water temperature from data loggers from the HALE-ALOHA Moorings in the North Pacific Ocean as part of the Joint Global Ocean Flux (JGOFS), the World Ocean Circulation Experiment (WOCE), and Hawaii Ocean Time-series (HOT) from 24 April 1998 to 03 May 1999 (NODC Accession 9900212)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Ocean water temperature data were collected from data loggers attached to the HALE-ALOHA Moorings in the North Pacific Ocean from 24 April 1998 to 03 May 1999. Data...

Carbonate chemistry of an in-situ free-ocean CO2 enrichment experiment (antFOCE) in comparison to short term variation in Antarctic coastal waters.

Science.gov (United States)

Stark, J S; Roden, N P; Johnstone, G J; Milnes, M; Black, J G; Whiteside, S; Kirkwood, W; Newbery, K; Stark, S; van Ooijen, E; Tilbrook, B; Peltzer, E T; Berry, K; Roberts, D

2018-02-12

Free-ocean CO 2 enrichment (FOCE) experiments have been deployed in marine ecosystems to manipulate carbonate system conditions to those predicted in future oceans. We investigated whether the pH/carbonate chemistry of extremely cold polar waters can be manipulated in an ecologically relevant way, to represent conditions under future atmospheric CO 2 levels, in an in-situ FOCE experiment in Antarctica. We examined spatial and temporal variation in local ambient carbonate chemistry at hourly intervals at two sites between December and February and compared these with experimental conditions. We successfully maintained a mean pH offset in acidified benthic chambers of -0.38 (±0.07) from ambient for approximately 8 weeks. Local diel and seasonal fluctuations in ambient pH were duplicated in the FOCE system. Large temporal variability in acidified chambers resulted from system stoppages. The mean pH, Ω arag and fCO 2 values in the acidified chambers were 7.688 ± 0.079, 0.62 ± 0.13 and 912 ± 150 µatm, respectively. Variation in ambient pH appeared to be mainly driven by salinity and biological production and ranged from 8.019 to 8.192 with significant spatio-temporal variation. This experiment demonstrates the utility of FOCE systems to create conditions expected in future oceans that represent ecologically relevant variation, even under polar conditions.

Are Hydrostatic Models Still Capable of Simulating Oceanic Fronts

Science.gov (United States)

2016-11-10

Hydrostatic Models Still Capable of Simulating Oceanic Fronts Yalin Fan Zhitao Yu Ocean Dynamics and Prediction Branch Oceanography Division FengYan Shi...OF PAGES 17. LIMITATION OF ABSTRACT Are Hydrostatic Models Still Capable of Simulating Oceanic Fronts? Yalin Fan, Zhitao Yu, and, Fengyan Shi1 Naval...mixed layer and thermocline simulations as well as large scale circulations. Numerical experiments are conducted using hydrostatic (HY) and

Indian Ocean and Indian summer monsoon: relationships without ENSO in ocean-atmosphere coupled simulations

Science.gov (United States)

Crétat, Julien; Terray, Pascal; Masson, Sébastien; Sooraj, K. P.; Roxy, Mathew Koll

2017-08-01

The relationship between the Indian Ocean and the Indian summer monsoon (ISM) and their respective influence over the Indo-Western North Pacific (WNP) region are examined in the absence of El Niño Southern Oscillation (ENSO) in two partially decoupled global experiments. ENSO is removed by nudging the tropical Pacific simulated sea surface temperature (SST) toward SST climatology from either observations or a fully coupled control run. The control reasonably captures the observed relationships between ENSO, ISM and the Indian Ocean Dipole (IOD). Despite weaker amplitude, IODs do exist in the absence of ENSO and are triggered by a boreal spring ocean-atmosphere coupled mode over the South-East Indian Ocean similar to that found in the presence of ENSO. These pure IODs significantly affect the tropical Indian Ocean throughout boreal summer, inducing a significant modulation of both the local Walker and Hadley cells. This meridional circulation is masked in the presence of ENSO. However, these pure IODs do not significantly influence the Indian subcontinent rainfall despite overestimated SST variability in the eastern equatorial Indian Ocean compared to observations. On the other hand, they promote a late summer cross-equatorial quadrupole rainfall pattern linking the tropical Indian Ocean with the WNP, inducing important zonal shifts of the Walker circulation despite the absence of ENSO. Surprisingly, the interannual ISM rainfall variability is barely modified and the Indian Ocean does not force the monsoon circulation when ENSO is removed. On the contrary, the monsoon circulation significantly forces the Arabian Sea and Bay of Bengal SSTs, while its connection with the western tropical Indian Ocean is clearly driven by ENSO in our numerical framework. Convection and diabatic heating associated with above-normal ISM induce a strong response over the WNP, even in the absence of ENSO, favoring moisture convergence over India.

76 FR 51353 - Nominations for Membership on the Ocean Research Advisory Panel

Science.gov (United States)

2011-08-18

... Leadership Council (NORLC), the governing body of the National Oceanographic Partnership Program (NOPP... extended expertise and experience in the field of ocean science and/or ocean resource management... balance a range of geographic and sector representation and experience. Applicants must be U.S. citizens...

The influence of the ocean circulation state on ocean carbon storage and CO2 drawdown potential in an Earth system model

Science.gov (United States)

Ödalen, Malin; Nycander, Jonas; Oliver, Kevin I. C.; Brodeau, Laurent; Ridgwell, Andy

2018-03-01

During the four most recent glacial cycles, atmospheric CO2 during glacial maxima has been lowered by about 90-100 ppm with respect to interglacials. There is widespread consensus that most of this carbon was partitioned in the ocean. It is, however, still debated which processes were dominant in achieving this increased carbon storage. In this paper, we use an Earth system model of intermediate complexity to explore the sensitivity of ocean carbon storage to ocean circulation state. We carry out a set of simulations in which we run the model to pre-industrial equilibrium, but in which we achieve different states of ocean circulation by changing forcing parameters such as wind stress, ocean diffusivity and atmospheric heat diffusivity. As a consequence, the ensemble members also have different ocean carbon reservoirs, global ocean average temperatures, biological pump efficiencies and conditions for air-sea CO2 disequilibrium. We analyse changes in total ocean carbon storage and separate it into contributions by the solubility pump, the biological pump and the CO2 disequilibrium component. We also relate these contributions to differences in the strength of the ocean overturning circulation. Depending on which ocean forcing parameter is tuned, the origin of the change in carbon storage is different. When wind stress or ocean diapycnal diffusivity is changed, the response of the biological pump gives the most important effect on ocean carbon storage, whereas when atmospheric heat diffusivity or ocean isopycnal diffusivity is changed, the solubility pump and the disequilibrium component are also important and sometimes dominant. Despite this complexity, we obtain a negative linear relationship between total ocean carbon and the combined strength of the northern and southern overturning cells. This relationship is robust to different reservoirs dominating the response to different forcing mechanisms. Finally, we conduct a drawdown experiment in which we investigate

The influence of the ocean circulation state on ocean carbon storage and CO2 drawdown potential in an Earth system model

Directory of Open Access Journals (Sweden)

M. Ödalen

2018-03-01

Full Text Available During the four most recent glacial cycles, atmospheric CO2 during glacial maxima has been lowered by about 90–100 ppm with respect to interglacials. There is widespread consensus that most of this carbon was partitioned in the ocean. It is, however, still debated which processes were dominant in achieving this increased carbon storage. In this paper, we use an Earth system model of intermediate complexity to explore the sensitivity of ocean carbon storage to ocean circulation state. We carry out a set of simulations in which we run the model to pre-industrial equilibrium, but in which we achieve different states of ocean circulation by changing forcing parameters such as wind stress, ocean diffusivity and atmospheric heat diffusivity. As a consequence, the ensemble members also have different ocean carbon reservoirs, global ocean average temperatures, biological pump efficiencies and conditions for air–sea CO2 disequilibrium. We analyse changes in total ocean carbon storage and separate it into contributions by the solubility pump, the biological pump and the CO2 disequilibrium component. We also relate these contributions to differences in the strength of the ocean overturning circulation. Depending on which ocean forcing parameter is tuned, the origin of the change in carbon storage is different. When wind stress or ocean diapycnal diffusivity is changed, the response of the biological pump gives the most important effect on ocean carbon storage, whereas when atmospheric heat diffusivity or ocean isopycnal diffusivity is changed, the solubility pump and the disequilibrium component are also important and sometimes dominant. Despite this complexity, we obtain a negative linear relationship between total ocean carbon and the combined strength of the northern and southern overturning cells. This relationship is robust to different reservoirs dominating the response to different forcing mechanisms. Finally, we conduct a drawdown experiment

Effects of Precipitation on Ocean Mixed-Layer Temperature and Salinity as Simulated in a 2-D Coupled Ocean-Cloud Resolving Atmosphere Model

Science.gov (United States)

Li, Xiaofan; Sui, C.-H.; Lau, K-M.; Adamec, D.

1999-01-01

A two-dimensional coupled ocean-cloud resolving atmosphere model is used to investigate possible roles of convective scale ocean disturbances induced by atmospheric precipitation on ocean mixed-layer heat and salt budgets. The model couples a cloud resolving model with an embedded mixed layer-ocean circulation model. Five experiment are performed under imposed large-scale atmospheric forcing in terms of vertical velocity derived from the TOGA COARE observations during a selected seven-day period. The dominant variability of mixed-layer temperature and salinity are simulated by the coupled model with imposed large-scale forcing. The mixed-layer temperatures in the coupled experiments with 1-D and 2-D ocean models show similar variations when salinity effects are not included. When salinity effects are included, however, differences in the domain-mean mixed-layer salinity and temperature between coupled experiments with 1-D and 2-D ocean models could be as large as 0.3 PSU and 0.4 C respectively. Without fresh water effects, the nocturnal heat loss over ocean surface causes deep mixed layers and weak cooling rates so that the nocturnal mixed-layer temperatures tend to be horizontally-uniform. The fresh water flux, however, causes shallow mixed layers over convective areas while the nocturnal heat loss causes deep mixed layer over convection-free areas so that the mixed-layer temperatures have large horizontal fluctuations. Furthermore, fresh water flux exhibits larger spatial fluctuations than surface heat flux because heavy rainfall occurs over convective areas embedded in broad non-convective or clear areas, whereas diurnal signals over whole model areas yield high spatial correlation of surface heat flux. As a result, mixed-layer salinities contribute more to the density differences than do mixed-layer temperatures.

Investigation of land ice-ocean interaction with a fully coupled ice-ocean model: 1. Model description and behavior

Science.gov (United States)

Goldberg, D. N.; Little, C. M.; Sergienko, O. V.; Gnanadesikan, A.; Hallberg, R.; Oppenheimer, M.

2012-06-01

Antarctic ice shelves interact closely with the ocean cavities beneath them, with ice shelf geometry influencing ocean cavity circulation, and heat from the ocean driving changes in the ice shelves, as well as the grounded ice streams that feed them. We present a new coupled model of an ice stream-ice shelf-ocean system that is used to study this interaction. The model is capable of representing a moving grounding line and dynamically responding ocean circulation within the ice shelf cavity. Idealized experiments designed to investigate the response of the coupled system to instantaneous increases in ocean temperature show ice-ocean system responses on multiple timescales. Melt rates and ice shelf basal slopes near the grounding line adjust in 1-2 years, and downstream advection of the resulting ice shelf thinning takes place on decadal timescales. Retreat of the grounding line and adjustment of grounded ice takes place on a much longer timescale, and the system takes several centuries to reach a new steady state. During this slow retreat, and in the absence of either an upward-or downward-sloping bed or long-term trends in ocean heat content, the ice shelf and melt rates maintain a characteristic pattern relative to the grounding line.

Global ocean monitoring for the World Climate Research Programme.

Science.gov (United States)

Revelle, R; Bretherton, F

1986-07-01

Oceanic research and modelling for the World Climate Research Program will utilize several recently-developed instruments and measuring techniques as well as well-tested, long-used instruments. Ocean-scanning satellites will map the component of the ocean-surface topography related to ocean currents and mesoscale eddies and to fluctuating water volumes caused by ocean warming and cooling. Other satellite instruments will measure the direction and magnitude of wind stress on the sea surface, surface water temperatures, the distribution of chlorophyll and other photosynthetic pigments, the characteristics of internal waves, and possible precipitation over the ocean. Networks of acoustic transponders will obtain a three-dimensional picture of the distribution of temperature from the surface down to mid-depth and of long-term changes in temperature at depth. Ocean research vessels will determine the distribution and fate of geochemical tracers and will also make high-precision, deep hydrographic casts. Ships of opportunity, using expendable instruments, will measure temperature, salinity and currents in the upper water layers. Drifting and anchored buoys will also measure these properties as well as those of the air above the sea surface. Tide gauges installed on islands and exposed coastal locations will measure variations in monthly and shorter-period mean sea level. These tide gauges will provide 'ground truth' for the satellite maps of sea-surface topography, and will also determine variations in ocean currents and temperature.All these instruments will be used in several major programs, the most ambitious of which is the World Ocean Circulation Experiment (WOCE) designed to obtain global measurements of major currents throughout the world ocean, greater understanding of the transformation of water masses, and the role of advective, convective, and turbulent processes in exchange of properties between surface and deep-ocean layers.A five- to ten-year experiment

Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs

KAUST Repository

Cerezo, Maria Isabel; Agusti, Susana

2015-01-01

One way organic pollutants reach remote oceanic regions is by atmospheric transport. During the Malaspina-2010 expedition, across the Atlantic, Indian, and Pacific Oceans, we analyzed the polycyclic aromatic hydrocarbon (PAH) effects on oceanic microbial food webs. We performed perturbation experiments adding PAHs to classic dilution experiments. The phytoplankton growth rates were reduced by more than 5 times, being Prochlorococcus spp. the most affected. 62% of the experiments showed a reduction in the grazing rates due to the presence of PAHs. For the remaining experiments, grazing usually increased likely due to cascading effects. We identified changes in the slope of the relation between the growth rate and the dilution fraction induced by the pollutants, moving from no grazing to V-shape, or to negative slope, indicative of grazing increase by cascade effects and alterations of the grazers' activity structure. Our perturbation experiments indicate that PAHs could influence the structure oceanic food-webs structure.

Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs

KAUST Repository

Cerezo, Maria Isabel

2015-11-01

One way organic pollutants reach remote oceanic regions is by atmospheric transport. During the Malaspina-2010 expedition, across the Atlantic, Indian, and Pacific Oceans, we analyzed the polycyclic aromatic hydrocarbon (PAH) effects on oceanic microbial food webs. We performed perturbation experiments adding PAHs to classic dilution experiments. The phytoplankton growth rates were reduced by more than 5 times, being Prochlorococcus spp. the most affected. 62% of the experiments showed a reduction in the grazing rates due to the presence of PAHs. For the remaining experiments, grazing usually increased likely due to cascading effects. We identified changes in the slope of the relation between the growth rate and the dilution fraction induced by the pollutants, moving from no grazing to V-shape, or to negative slope, indicative of grazing increase by cascade effects and alterations of the grazers\\' activity structure. Our perturbation experiments indicate that PAHs could influence the structure oceanic food-webs structure.

Ocean FEST and TECH: Inspiring Hawaii's Students to Pursue Ocean, Earth and Environmental Science Careers

Science.gov (United States)

Bruno, B. C.; Wren, J. L.; Ayau, J. F.

2013-12-01

Ocean TECH (Technology Expands Career Horizons) is a new initiative funded by NSF/GeoEd to stimulate interest in ocean, earth and environmental science careers - and the college majors that lead to such careers - among Hawaii's underrepresented students in grades 6-14. The Ocean TECH project features hands-on ocean science and technology and interactions with career professionals. Ocean TECH builds upon Ocean FEST (Families Exploring Science Together), a previous NSF/OEDG project aimed at teaching fun hands-on science in culturally and locally relevant ways to Hawaii's elementary school students and their families. Ocean FEST was rigorously evaluated (including cognitive pre-testing developed in partnership with external evaluators) and shown to be successful both in teaching science content and changing attitudes toward ocean, earth and environmental science careers. Over the course of the four-year grant, Ocean FEST reached 20,99 students and adults, including 636 classroom teachers and other volunteers who assisted with program delivery, most of whom were from underrepresented groups. For more info on Ocean FEST: http://oceanfest.soest.hawaii.edu/ Ocean TECH events have various formats, but common themes include: (1) Using technology as a hook to engage students in ocean, earth and environmental science. (2) Bringing middle school through community college students to college campuses, where they engage in hands-on science activities and learn about college majors. (3) Drawing direct links between the students' hands-on science activities and the research currently occurring at the UH Manoa's School of Ocean and Earth Science and Technology (SOEST), such as C-MORE and HOT research. (4) Respecting and valuing students' local knowledge and experiences. (5) Explicitly showing, through concrete examples, how becoming an ocean, earth or environmental scientist addresses would beneit Hawaii (6) Having graduate students from diverse backgrounds serve as instructors and

Eddy-resolving 1/10° model of the World Ocean

Science.gov (United States)

Ibrayev, R. A.; Khabeev, R. N.; Ushakov, K. V.

2012-02-01

The first results on simulating the intra-annual variability of the World Ocean circulation by use of the eddy-resolving model are considered. For this purpose, a model of the World Ocean with a 1/10° horizontal resolution and 49 vertical levels was developed (a 1/10 × 1/10 × 49 model of the World Ocean). This model is based on the traditional system of three-dimensional equations of the large-scale dynamics of the ocean and boundary conditions with an explicit allowance for water fluxes on the free surface of the ocean. The equations are written in the tripolar coordinate system. The numerical method is based on the separation of the barotropic and baroclinic components of the solution. Discretization in time is implemented using explicit schemes allowing effective parallelization for a large number of processors. The model uses the sub-models of the boundary layer of the atmosphere and the submodel of sea-ice thermodynamics. The model of the World Ocean was developed at the Institute of Numerical Mathematics of the Russian Academy of Sciences (INM RAS) and the P.P. Shirshov Institute of Oceanogy (IO RAS). The formulation of the problem of simulating the intra-annual variability of thermohydrodynamic processes of the World Ocean and the parameterizations that were used are considered. In the numerical experiment, the temporal evolution of the atmospheric effect is determined by the normal annual cycle according to the conditions of the international Coordinated Ocean-Ice Reference Experiment (CORE-I). The calculation was carried out on a multiprocessor computer with distributed memory; 1601 computational cores were used. The presented analysis demonstrates that the obtained results are quite satisfactory when compared to the results that were obtained by other eddy-resolving models of the global ocean. The analysis of the model solution is, to a larger extent, of a descriptive character. A detailed analysis of the results is to be presented in following works

Global Ocean Carbon and Biogeochemistry Coordination

Science.gov (United States)

Telszewski, Maciej; Tanhua, Toste; Palacz, Artur

2016-04-01

multidisciplinary global ocean observing system. Over the past 4-5 years IOCCP's long standing experience in coordinating biogeochemical observations and data flows globally, resulted in assuming a leadership role during the design and implementation of the biogeochemistry portion of the Framework for Ocean Observing (FOO, 2012). To optimize and enhance the global ocean observing system IOCCP started to implement major elements of the system's approach outlined in the FOO. Starting by setting of ocean observing requirements representing the needs of societal and scientific stakeholders, followed by development of a set of essential ocean variables (EOVs) with spatial and temporal resolution specifications to best meet current demands for data and information services given current and potential national capabilities. The IOCCP works directly with projects and programs programmatically connected to GOOS as well as the WMO-IOC JCOMM to integrate ocean carbon and biogeochemistry observation information into the plans of the Global Climate Observing System in support of the United Nations Framework Convention on Climate Change, the World Summit on Sustainable Development, the Group on Earth Observations, and other international and intergovernmental strategies. We would like to update our partners across disciplines and domains on our short- and long-term strategies as well as learn from their combined experience and knowledge so that our individual activities align more with those undertaken by our counterparts in biological and physical oceanography as well as in terrestrial and atmospheric domains.

The Chinese FY-1 Meteorological Satellite Application in Observation on Oceanic Environment

Science.gov (United States)

Weimin, S.

meteorological satellite is stated in this paper. exploration of the ocean resources has been a very important question of global strategy in the world. The exploration of the ocean resources includes following items: Making full use of oceanic resources and space, protecting oceanic environment. to observe the ocean is by using of satellite. In 1978, US successfully launched the first ocean observation satellite in the world --- Sea Satellite. It develops ancient oceanography in to advanced space-oceanography. FY-1 B and FY- IC respectively. High quality data were acquired at home and abroad. FY-1 is Chinese meteorological satellite, but with 0.43 ~ 0.48 μm ,0.48 ~ 0.53 μm and 0.53 ~ 0.58 μm three ocean color channels, actually it is a multipurpose remote sensing satellite of meteorology and oceanography. FY-1 satellite's capability of observation on ocean partly, thus the application field is expanded and the value is increased. With the addition of oceanic channels on FY-1, the design of the satellite is changed from the original with meteorological observation as its main purpose into remote sensing satellite possessing capability of observing meteorology and ocean as well. Thus, the social and economic benefit of FY-1 is increased. the social and economic benefit of the development of the satellite is the key technique in the system design of the satellite. technically feasible but also save the funds in researching and manufacturing of the satellite, quicken the tempo of researching and manufacturing satellite. the scanning radiometer for FY-1 is conducted an aviation experiment over Chinese ocean. This experiment was of vital importance to the addition of oceanic observation channel on FY-1. FY-1 oceanic channels design to be correct. detecting ocean color. This is the unique character of Chinese FY-1 meteorological satellite. meteorological remote sensing channel on FY-1 to form detecting capability of three visible channels: red, yellow and blue

Using Virtual Reality to Bring Ocean Science Field Experiences to the Classroom and Beyond

Science.gov (United States)

Waite, A. J.; Rosenberg, A.; Frehm, V.; Gravinese, P.; Jackson, J.; Killingsworth, S.; Williams, C.

2017-12-01

While still in its infancy, the application of virtual reality (VR) technology to classroom education provides unparalleled opportunities to transport students to otherwise inaccessible localities and increase awareness of and engagement in STEAM fields. Here we share VR programming in development by the ANGARI Foundation, a 501(c)(3) nonprofit committed to advancing ocean science research and education. ANGARI Foundation's series of thematic VR films features the research of ocean scientists from onboard the Foundation's research vessel, R/V ANGARI. The films are developed and produced through an iterative process between expedition scientists, the film production team, and ANGARI staff and Educator Council members. Upon completion of filming, the K-12 and informal educators of ANGARI's Educator Council work with ANGARI staff and affiliated scientists to develop and implement standards-aligned (e.g. Next Generation Science Standards and International Baccalaureate) lesson plans for the classroom. The goal of ANGARI Foundation's VR films is to immerse broad audiences in the marine environment, while actively engaging them in the at-sea scientific methods of expert scientists, ultimately increasing knowledge of our oceans and promoting their conservation. The foundation's VR films and developed lessons are made available for free to the public via YouTube and www.ANGARI.org. While South Florida educators may request that ANGARI Foundation visit their classrooms and bring the necessary headsets to run the experience, the Foundation is also partnering with VR hardware companies to facilitate the acquisition and adoption of VR headsets by schools in the U.S. and abroad. In this presentation we will share our most recent VR film that highlights coral reef ecosystems and the Florida Reef Tract, taking an interdisciplinary approach to investigating how it has changed over time and the issues and opportunities it currently faces. We will also discuss classroom

Structure of the marine atmospheric boundary layer over an oceanic thermal front: SEMAPHORE experiment

Science.gov (United States)

Kwon, B. H.; BéNech, B.; Lambert, D.; Durand, P.; Druilhet, A.; Giordani, H.; Planton, S.

1998-10-01

The Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, the third phase of which took place between October 4 and November 17, 1993, was conducted over the oceanic Azores Current located in the Azores basin and mainly marked at the surface by a thermal front due to the gradient of the sea surface temperature (SST) of about 1° to 2°C per 100 km. The evolution of the marine atmospheric boundary layer (MABL) over the SST front was studied with two aircraft and a ship in different meteorological conditions. For each case, the influence of the incoming air direction with respect to the orientation of the oceanic front was taken into account. During the campaign, advanced very high resolution radiometer pictures did not show any relation between the SST field and the cloud cover. The MABL was systematically thicker on the warm side than on the cold side. The mean MABL structure described from aircraft data collected in a vertical plane crossing the oceanic front was characterized by (1) an atmospheric horizontal gradient of 1° to 2°C per 100 km in the whole depth of the mixed layer and (2) an increase of the wind intensity from the cold to the warm side when the synoptic wind blew from the cold side. The surface sensible heat (latent heat) flux always increased from the cold to the warm sector owing to the increase of the wind and of the temperature (specific humidity) difference between the surface and the air. Turbulence increased from the cold to the warm side in conjunction with the MABL thickening, but the normalized profiles presented the same structure, regardless of the position over the SST front. In agreement with the Action de Recherche Programme te Petite Echelle and Grande Echelle model, the mean temperature and momentum budgets were highly influenced by the horizontal temperature gradient. In particular, the strong ageostrophic influence in the MABL above the SST front seems

75 FR 18778 - Safety Zone; Ocean City Air Show 2010, Atlantic Ocean, Ocean City, MD

Science.gov (United States)

2010-04-13

...-AA00 Safety Zone; Ocean City Air Show 2010, Atlantic Ocean, Ocean City, MD AGENCY: Coast Guard, DHS... zone on the Atlantic Ocean in the vicinity of Ocean City, Maryland to support the Ocean City Air Show. This action is intended to restrict vessel traffic movement on the Atlantic Ocean to protect mariners...

ISHTE deep-ocean corers and heater-implant system. Final report

Energy Technology Data Exchange (ETDEWEB)

Olson, L. O.; Harrison, J. G.

1982-09-01

Seafloor instrumentation systems are being developed for the In-Situ Heat Transfer Experiment (ISHTE) to determine the thermal conductivity of deep ocean sediments. As part of the experiment, a heat canister will be implanted into the sediment. Also, after about one year on the seafloor, core samplers are to be actuated to gather sediment samples. This report describes the deep ocean piston corers and the heater-implant drive system.

First mesocosm experiments to study the impacts of ocean acidification on plankton communities in the NW Mediterranean Sea (MedSeA project)

Science.gov (United States)

Gazeau, F.; Sallon, A.; Maugendre, L.; Louis, J.; Dellisanti, W.; Gaubert, M.; Lejeune, P.; Gobert, S.; Borges, A. V.; Harlay, J.; Champenois, W.; Alliouane, S.; Taillandier, V.; Louis, F.; Obolensky, G.; Grisoni, J.-M.; Guieu, C.

2017-02-01

There is a growing international interest in studying the effects of ocean acidification on plankton communities that play a major role in the global carbon cycle and in the consumption of atmospheric CO2 via the so-called biological pump. Recently, several mesocosm experiments reported on the effect of ocean acidification on marine plankton communities, although the majority were performed in eutrophic conditions or following nutrient addition. The objective of the present study was to perform two mesocosm experiments in the oligo- to meso-trophic Northwestern Mediterranean Sea during two seasons with contrasting environmental conditions: in summer 2012 in the Bay of Calvi (Corsica, France) and in winter 2013 in the Bay of Villefranche (France). This paper describes the objectives of these experiments, the study sites, the experimental set-up and the environmental and experimental conditions during the two experiments. The 20-day experiment in the Bay of Calvi was undoubtedly representative of summer conditions in the Northwestern Mediterranean Sea with low nutrient and chlorophyll a concentrations, warm waters and high surface solar irradiance. In contrast, the winter experiment, which was reduced to 12 days because of bad weather conditions, failed to reproduce the mesotrophic conditions typical of the wintertime in this area. Indeed, a rapid increase in phytoplankton biomass during the acidification phase led to a strong decrease in nitrate concentrations and an unrealistic N and P co-limitation at this period of the year. An overview of the 11 other papers related to this study and published in this special issue is provided.

MODELING OF MOVING DEFORMABLE CONTINENTS BY ACTIVE TRACERS: CLOSING AND OPENING OF OCEANS, RECIRCULATION OF OCEANIC CRUST

Directory of Open Access Journals (Sweden)

A. V. Bobrov

2018-01-01

Full Text Available The evolution of the ‘mantle – moving deformable continents’ system has been studied by numerical experiments. The continents move self-consistently with the mantle flows of thermo-compositional convection. Our model (two-dimensional mantle convection, non-Newtonian rheology, the presence of deformable continents demonstrates the main features of global geodynamics: convergence and divergence of continents; appearance and disappearance of subduction zones; backrolling of subduction zones; restructuring of mantle flows; stretching, breakup and divergence of continents; opening and closing of oceans; oceanic crust recirculation in the mantle, and overriding of hot mantle plumes by continents. In our study, the continental crust is modeled by active markers which transfer additional viscosity and buoyancy, while the continental lithosphere is marked only by increased viscosity with neutral buoyancy. The oceanic crust, in its turn, is modeled by active markers that have only an additional buoyancy. The principal result of our modeling is a consistency between the numerical calculations and the bimodal dynamics of the real Earth: the oceanic crust, despite its positive buoyancy near the surface, submerges in subduction zones and sinks deep into the mantle. (Some part of the oceanic crust remains attached to the continental margins for a long time. In contrast to the oceanic crust, the continental crust does not sink in subduction zones. The continental lithosphere, despite its neutral buoyancy, also remains on the surface due to its viscosity and coupling with the continental crust. It should be noted that when a continent overrides a subduction zone, the subduction zone disappears, and the flows in the mantle are locally reorganized. The effect of basalt-eclogite transition in the oceanic crust on the mantle flow pattern and on the motion of continents has been studied. Our numerical experiments show that the inclusion of this effect in the

Shallow Carbon Export from an Iron fertilised Plankton Bloom in the Southern Ocean

Science.gov (United States)

Sanders, R.; Pollard, R.; Morris, P.; Statham, P.; Moore, C. M. M.; Lucas, M.

2009-04-01

Some regions of the global ocean, notably the Southern Ocean, have high levels of macronutrients yet low levels of chlorophyll (the high nutrient, low chlorophyll or HNLC condition). Numerous artificial iron fertilization experiments conducted in the Southern Ocean have resulted in enhanced phytoplankton biomass and macronutrient drawdown. However the subsequent long-term biogeochemical consequences of such iron fertilization are unclear due in part to the limited size and duration of such experiments. An alternative way to assess the affect of iron over the Southern Ocean biological carbon pump is to observe the evolution of plankton production in regions of the Southern Ocean where shallow topography and Ocean currents interact to promote to release terrestrial iron into HNLC waters. During 2004-5 RRS Discovery conduced a complex programme of observations in such a region around the Crozet Islands in the SW Indian Ocean. The results of this programme, focussing on a quantitative estimate of carbon export per unit iron addition, will be presented.

How ocean acidification can benefit calcifiers.

Science.gov (United States)

Connell, Sean D; Doubleday, Zoë A; Hamlyn, Sarah B; Foster, Nicole R; Harley, Christopher D G; Helmuth, Brian; Kelaher, Brendan P; Nagelkerken, Ivan; Sarà, Gianluca; Russell, Bayden D

2017-02-06

Reduction in seawater pH due to rising levels of anthropogenic carbon dioxide (CO 2 ) in the world's oceans is a major force set to shape the future of marine ecosystems and the ecological services they provide [1,2]. In particular, ocean acidification is predicted to have a detrimental effect on the physiology of calcifying organisms [3]. Yet, the indirect effects of ocean acidification on calcifying organisms, which may counter or exacerbate direct effects, is uncertain. Using volcanic CO 2 vents, we tested the indirect effects of ocean acidification on a calcifying herbivore (gastropod) within the natural complexity of an ecological system. Contrary to predictions, the abundance of this calcifier was greater at vent sites (with near-future CO 2 levels). Furthermore, translocation experiments demonstrated that ocean acidification did not drive increases in gastropod abundance directly, but indirectly as a function of increased habitat and food (algal biomass). We conclude that the effect of ocean acidification on algae (primary producers) can have a strong, indirect positive influence on the abundance of some calcifying herbivores, which can overwhelm any direct negative effects. This finding points to the need to understand ecological processes that buffer the negative effects of environmental change. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interactions of the tropical oceans. Rev.ed.

International Nuclear Information System (INIS)

Latif, M.; Barnett, T.P.

1994-01-01

We have investigated the interactions of the tropical oceans on interannual time scales by conducting a series of uncoupled atmospheric and oceanic general circulation experiments and hybrid coupled model simulations. Our results illustrate the key role of the El Nino/Southern Oscillation (ENSO) phenomenon in generating interannual variability in all three tropical ocean basins. Sea surface temperature (SST) anomalies in the tropical Pacific force via a changed atmospheric circulation SST anomalies of the same sign in the Indian Ocean and SST anomalies of the opposite sign in the Atlantic. However, although air-sea interactions in the Indian and Atlantic Oceans are much weaker than those in the Pacific, they contribute significantly to the variability in these two regions. The role of these air-sea interactions is mainly that of an amplifyer by which the ENSO induced signals are enhanced in ocean and atmosphere. This process is particularly important in the tropical Atlantic region. We investigated also whether ENSO is part of a zonally propagating ''wave'' which travels around the globe with a time scale of several years. Consistent with observations, the upper ocean heat content in the various numerical simulations seems to propagate slowly around the globe. SST anomalies in the Pacific Ocean introduce a global atmospheric response which in turn forces variations in the other tropical oceans. Since the different oceans exhibit different response characteristics to low-frequency wind changes, the individual tropical ocean responses can add up coincidentally to look like a global wave, and that appears to be the situation. In particular, no evidence is found that the Indian Ocean can significantly affect the ENSO cycle in the Pacific. Finally, the potential for climate forecasts in the Indian and Atlantic Oceans appears to be enhanced if one includes, in a coupled way, remote influences from the Pacific. (orig.)

Adubação nitrogenada e potássica de bromeliáceas cultivadas em fibra de coco e esterco bovino Nitrogen and potassium fertilization of Bromeliaceae grown in coconut fiber and cattle manure

Directory of Open Access Journals (Sweden)

Tatiana L do Amaral

2009-09-01

. The experiment was a factorial (4x4 with four nitrogen (N and potassium (K levels (0; 375; 562.6 and 750 mg L-1of N and 0; 468.8; 703.2 e 937.6 mg L-1 of K, in randomized blocks, using four replications for Aechmea blanchetiana and Neoregelia 'Sheba' and three replications for Orthophytum gurkenii and Vriesea gigantea, and two plants per plot. Aechmea blanchetiana and Neoregelia 'Sheba' plants were grown in 50% coconut fiber + 50% cattle manure, whereas Orthophytum gurkenii and Vriesea gigantea were grown in 100% coconut fiber. The N (0; 375; 562.6 and 750 mg L-1 and K levels (0; 468.8; 703.2 and 937.6 mg L-1, on the substrate, correspond, respectively, to 0; 187.5; 281.3; 375 mg/plant of N and 0; 234.4; 351.6; 468.8 mg/plant of K. The P fertilization was fixed as 50 mg L-1 of P corresponding to 25 mg/plant of P, except for Neoregelia 'Sheba' which was inoculated with 25 mL/container (0.5 L of the mixed inoculum (Glomus geosporum, Acaulospora laevis, Acaulospora mellea without P fertilization. The fertilization with 305.1 mg/plant of N was the most efficient for Aechmea blanchetiana increment of plant height. In Orthophytum gurkenii the fertilization with 250 mg/plant of N caused the highest leaf number and rosette diameter. The N and K fertilization was not beneficial for Vriesea gigantea plants. In Neoregelia 'Sheba' 315 mg/plant of N caused the greatest plant height and rosette diameter.

Ocean acidification effects on mesozooplankton community development: Results from a long-term mesocosm experiment

Science.gov (United States)

Algueró-Muñiz, María; Alvarez-Fernandez, Santiago; Thor, Peter; Bach, Lennart T.; Esposito, Mario; Horn, Henriette G.; Ecker, Ursula; Langer, Julia A. F.; Taucher, Jan; Malzahn, Arne M.; Riebesell, Ulf; Boersma, Maarten

2017-01-01

Ocean acidification may affect zooplankton directly by decreasing in pH, as well as indirectly via trophic pathways, where changes in carbon availability or pH effects on primary producers may cascade up the food web thereby altering ecosystem functioning and community composition. Here, we present results from a mesocosm experiment carried out during 113 days in the Gullmar Fjord, Skagerrak coast of Sweden, studying plankton responses to predicted end-of-century pCO2 levels. We did not observe any pCO2 effect on the diversity of the mesozooplankton community, but a positive pCO2 effect on the total mesozooplankton abundance. Furthermore, we observed species-specific sensitivities to pCO2 in the two major groups in this experiment, copepods and hydromedusae. Also stage-specific pCO2 sensitivities were detected in copepods, with copepodites being the most responsive stage. Focusing on the most abundant species, Pseudocalanus acuspes, we observed that copepodites were significantly more abundant in the high-pCO2 treatment during most of the experiment, probably fuelled by phytoplankton community responses to high-pCO2 conditions. Physiological and reproductive output was analysed on P. acuspes females through two additional laboratory experiments, showing no pCO2 effect on females’ condition nor on egg hatching. Overall, our results suggest that the Gullmar Fjord mesozooplankton community structure is not expected to change much under realistic end-of-century OA scenarios as used here. However, the positive pCO2 effect detected on mesozooplankton abundance could potentially affect biomass transfer to higher trophic levels in the future. PMID:28410436

Flight dynamics facility operational orbit determination support for the ocean topography experiment

Science.gov (United States)

Bolvin, D. T.; Schanzle, A. F.; Samii, M. V.; Doll, C. E.

1991-01-01

The Ocean Topography Experiment (TOPEX/POSEIDON) mission is designed to determine the topography of the Earth's sea surface across a 3 yr period, beginning with launch in June 1992. The Goddard Space Flight Center Dynamics Facility has the capability to operationally receive and process Tracking and Data Relay Satellite System (TDRSS) tracking data. Because these data will be used to support orbit determination (OD) aspects of the TOPEX mission, the Dynamics Facility was designated to perform TOPEX operational OD. The scientific data require stringent OD accuracy in navigating the TOPEX spacecraft. The OD accuracy requirements fall into two categories: (1) on orbit free flight; and (2) maneuver. The maneuver OD accuracy requirements are of two types; premaneuver planning and postmaneuver evaluation. Analysis using the Orbit Determination Error Analysis System (ODEAS) covariance software has shown that, during the first postlaunch mission phase of the TOPEX mission, some postmaneuver evaluation OD accuracy requirements cannot be met. ODEAS results also show that the most difficult requirements to meet are those that determine the change in the components of velocity for postmaneuver evaluation.

Regional impacts of ocean color on tropical Pacific variability

OpenAIRE

W. Anderson; A. Gnanadesikan; A. Wittenberg

2009-01-01

The role of the penetration length scale of shortwave radiation into the surface ocean and its impact on tropical Pacific variability is investigated with a fully coupled ocean, atmosphere, land and ice model. Previous work has shown that removal of all ocean color results in a system that tends strongly towards an El Niño state. Results from a suite of surface chlorophyll perturbation experiments show that the mean state and variability of the tropical Pacific is highly se...

History of critical experiments at Pajarito Site

International Nuclear Information System (INIS)

Paxton, H.C.

1983-03-01

This account describes critical and subcritical assemblies operated remotely at the Pajarito Canyon Site at the Los Alamos National Laboratory. Earliest assemblies, directed exclusively toward the nuclear weapons program, were for safety tests. Other weapon-related assemblies provided neutronic information to check detailed weapon calculations. Topsy, the first of these critical assemblies, was followed by Lady Godiva, Jezebel, Flattop, and ultimately Big Ten. As reactor programs came to Los Alamos, design studies and mockups were tested at Pajarito Site. For example, nearly all 16 Rover reactors intended for Nevada tests were preceded by zero-power mockups and proof tests at Pajarito Site. Expanded interest and capability led to fast-pulse assemblies, culminating in Godiva IV and Skua, and to the Kinglet and Sheba solution assemblies

History of critical experiments at Pajarito Site

Energy Technology Data Exchange (ETDEWEB)

Paxton, H.C.

1983-03-01

This account describes critical and subcritical assemblies operated remotely at the Pajarito Canyon Site at the Los Alamos National Laboratory. Earliest assemblies, directed exclusively toward the nuclear weapons program, were for safety tests. Other weapon-related assemblies provided neutronic information to check detailed weapon calculations. Topsy, the first of these critical assemblies, was followed by Lady Godiva, Jezebel, Flattop, and ultimately Big Ten. As reactor programs came to Los Alamos, design studies and mockups were tested at Pajarito Site. For example, nearly all 16 Rover reactors intended for Nevada tests were preceded by zero-power mockups and proof tests at Pajarito Site. Expanded interest and capability led to fast-pulse assemblies, culminating in Godiva IV and Skua, and to the Kinglet and Sheba solution assemblies.

Ocean acidification and marine microorganisms: responses and consequences

Directory of Open Access Journals (Sweden)

Surajit Das

2015-10-01

Full Text Available Ocean acidification (OA is one of the global issues caused by rising atmospheric CO2. The rising pCO2 and resulting pH decrease has altered ocean carbonate chemistry. Microbes are key components of marine environments involved in nutrient cycles and carbon flow in marine ecosystems. However, these marine microbes and the microbial processes are sensitive to ocean pH shift. Thus, OA affects the microbial diversity, primary productivity and trace gases emission in oceans. Apart from that, it can also manipulate the microbial activities such as quorum sensing, extracellular enzyme activity and nitrogen cycling. Short-term laboratory experiments, mesocosm studies and changing marine diversity scenarios have illustrated undesirable effects of OA on marine microorganisms and ecosystems. However, from the microbial perspective, the current understanding on effect of OA is based mainly on limited experimental studies. It is challenging to predict response of marine microbes based on such experiments for this complex process. To study the response of marine microbes towards OA, multiple approaches should be implemented by using functional genomics, new generation microscopy, small-scale interaction among organisms and/or between organic matter and organisms. This review focuses on the response of marine microorganisms to OA and the experimental approaches to investigate the effect of changing ocean carbonate chemistry on microbial mediated processes.

The impact of ocean acidification on the early life stages of surf clams and the interactive effects of feeding and temperature from laboratory experiment studies from 2011-07-12 to 2012-06-17 (NODC Accession 0123314)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of ocean acidification on the Atlantic surfclam, Spisula...

Changes in summer sea ice, albedo, and portioning of surface solar radiation in the Pacific sector of Arctic Ocean during 1982-2009

Science.gov (United States)

Lei, Ruibo; Tian-Kunze, Xiangshan; Leppäranta, Matti; Wang, Jia; Kaleschke, Lars; Zhang, Zhanhai

2016-08-01

SSM/I sea ice concentration and CLARA black-sky composite albedo were used to estimate sea ice albedo in the region 70°N-82°N, 130°W-180°W. The long-term trends and seasonal evolutions of ice concentration, composite albedo, and ice albedo were then obtained. In July-August 1982-2009, the linear trend of the composite albedo and the ice albedo was -0.069 and -0.046 units per decade, respectively. During 1 June to 19 August, melting of sea ice resulted in an increase of solar heat input to the ice-ocean system by 282 MJ·m-2 from 1982 to 2009. However, because of the counter-balancing effects of the loss of sea ice area and the enhanced ice surface melting, the trend of solar heat input to the ice was insignificant. The summer evolution of ice albedo matched the ice surface melting and ponding well at basin scale. The ice albedo showed a large difference between the multiyear and first-year ice because the latter melted completely by the end of a melt season. At the SHEBA geolocations, a distinct change in the ice albedo has occurred since 2007, because most of the multiyear ice has been replaced by first-year ice. A positive polarity in the Arctic Dipole Anomaly could be partly responsible for the rapid loss of summer ice within the study region in the recent years by bringing warmer air masses from the south and advecting more ice toward the north. Both these effects would enhance ice-albedo feedback.

Ocean Acidification: Adaptive Challenge or Extinction Threat?

Science.gov (United States)

Caldeira, K.

2012-12-01

Most of the carbon dioxide that we emit to this atmosphere through fossil-fuel burning and deforestation is ultimately absorbed by the oceans. The effects of excess carbon dioxide on the inorganic chemistry of the ocean are largely well understood, but it is less clear what these chemical changes mean for the future of marine biota. Excess dissolved CO2 increases hydrogen-ion concentration (i.e., decreases pH) and decreases carbonate-ion concentrations, affecting the chemical speciation of nutrients and other chemicals dissolved in the ocean, and affecting the ability of organisms to form calcium carbonate shells or skeletons. Some organisms, such as corals, develop shells or skeletons made from aragonite, a particularly soluble form of calcium carbonate. The uptake of O2 and the release of CO2 from the blood of fish are affected by pH, with lower pH leading to a decrease in both O2 uptake and CO2 release. Of these concerns, the effects of excess CO2 on calcification may be the most worrisome. Doubling or quadrupling of atmospheric CO2 content within the space of a few centuries means doubling or quadrupling hydrogen-ion concentrations and halving or quartering the carbonate-ion concentration within a few centuries. Experiments and theory indicate that chemical changes of this magnitude could have important biotic consequences. Changes of this magnitude and rapidity have not occurred on this planet with the possible exception of various paroxysmal extreme events buried deep in Earth history. Most major changes to ocean chemistry occurred over millions of years allowing (i) seawater chemistry to be in approximate equilibrium with respect to riverine and sedimentary fluxes and (ii) marine biota to adapt in evolutionary time. Man's great geochemical experiment will go on at global scale for thousands of years. But experiments can be done in the laboratory in small tanks or in the sea in small enclosures only for limited periods of time. It is difficult to infer from

The Heterotrophic Bacterial Response During the Meso-scale Southern Ocean Iron Experiment (SOFeX)

Science.gov (United States)

Oliver, J. L.; Barber, R. T.; Ducklow, H. W.

2002-12-01

Previous meso-scale iron enrichments have demonstrated the stimulatory effect of iron on primary productivity and the accelerated flow of carbon into the surface ocean foodweb. In stratified waters, heterotrophic activity can work against carbon export by remineralizing POC and/or DOC back to CO2, effectively slowing the biological pump. To assess the response of heterotrophic activity to iron enrichment, we measured heterotrophic bacterial production and abundance during the Southern Ocean Iron Experiment (SOFeX). Heterotrophic bacterial processes primarily affect the latter of the two carbon export mechanisms, removal of DOC to the deep ocean. Heterotrophic bacterial production (BP), measured via tritiated thymidine (3H-TdR) and leucine (3H-Leu) incorporation, increased ~40% over the 18-d observation period in iron fertilized waters south of the Polar Front (South Patch). Also, South Patch BP was 61% higher than in the surrounding unfertilized waters. Abundance, measured by flow cytometry (FCM) and acridine orange direct counts (AODC), also increased in the South Patch from 3 to 5 x 108 cells liter-1, a 70% increase. Bacterial biomass increased from ~3.6 to 6.3 μg C liter-1, a clear indication that production rates exceeded removal rates (bactivory, viral lysis) over the course of 18 days. Biomass within the fertilized patch was 11% higher than in surrounding unfertilized waters reflecting a similar trend. This pattern is in contrast to SOIREE where no accumulation of biomass was observed. High DNA-containing (HDNA) cells detected by FCM also increased over time in iron fertilized waters from 20% to 46% relative to the total population suggesting an active subpopulation of cells that were growing faster than the removal rates. In iron fertilized waters north of the Polar Front (North Patch), BP and abundance were ~90% and 80% higher, respectively, than in unfertilized waters. Our results suggest an active bacterial population that responded to iron fertilization

Ocean acidification: the other CO2 problem.

Science.gov (United States)

Doney, Scott C; Fabry, Victoria J; Feely, Richard A; Kleypas, Joan A

2009-01-01

Rising atmospheric carbon dioxide (CO2), primarily from human fossil fuel combustion, reduces ocean pH and causes wholesale shifts in seawater carbonate chemistry. The process of ocean acidification is well documented in field data, and the rate will accelerate over this century unless future CO2 emissions are curbed dramatically. Acidification alters seawater chemical speciation and biogeochemical cycles of many elements and compounds. One well-known effect is the lowering of calcium carbonate saturation states, which impacts shell-forming marine organisms from plankton to benthic molluscs, echinoderms, and corals. Many calcifying species exhibit reduced calcification and growth rates in laboratory experiments under high-CO2 conditions. Ocean acidification also causes an increase in carbon fixation rates in some photosynthetic organisms (both calcifying and noncalcifying). The potential for marine organisms to adapt to increasing CO2 and broader implications for ocean ecosystems are not well known; both are high priorities for future research. Although ocean pH has varied in the geological past, paleo-events may be only imperfect analogs to current conditions.

Examples and applications in long-range ocean acoustics

International Nuclear Information System (INIS)

Vera, M D

2007-01-01

Acoustic energy propagates effectively to long ranges in the ocean interior because of the physical properties of the marine environment. Sound propagation in the ocean is relevant to a variety of studies in communication, climatology and marine biology. Examples drawn from ocean acoustics, therefore, are compelling to students with a variety of interests. The dependence of sound speed on depth results in a waveguide that permits the detection of acoustic energy at ranges, in some experiments, of thousands of kilometres. This effect serves as an illustration of Snell's law with a continuously variable index of refraction. Acoustic tomography also offers a means for imaging the ocean's thermal structure, because of the dependence of sound speed on temperature. The ability to perform acoustic thermometry for large transects of the ocean provides an effective means of studying climate change. This application in an area of substantial popular attention allows for an effective introduction to concepts in ray propagation. Aspects of computational ocean acoustics can be productive classroom examples in courses ranging from introductory physics to upper-division mathematical methods courses

Benthic disturbance and monitoring experiment in the Central Indian Ocean Basin

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.; Nath, B.N.

Environmental impact assessment studies for deep-sea manganese nodule mining have been initiated in the Central indian Ocean Basin since 1995. As a part of the first phase for collecting the benthic baseline data, echosounding, subbottom profiling...

Wave hindcast experiments in the Indian Ocean using MIKE 21 SW ...

Indian Academy of Sciences (India)

Wave prediction and hindcast studies are important in ocean engineering, coastal ... wave data can be used for the assessment of wave climate in offshore and coastal areas. In the .... for the change in performance during SW monsoon.

The geological record of ocean acidification

NARCIS (Netherlands)

Hönisch, B.; Ridgwell, A.; Schmidt, D.N.; Thomas, E.; Gibbs, S.J.; Sluijs, A.; Zeebe, R.; Kump, L.; Martindale, R.C.; Greene, S.E.; Kiessling, W.; Ries, J.; Zachos, J.C.; Royer, D.L.; Barker, S.; Marchitto Jr., T.M.; Moyer, R.; Pelejero, C.; Ziveri, P.; Foster, G.L.; Williams, B.

2012-01-01

Ocean acidification may have severe consequences for marine ecosystems; however, assessing its future impact is difficult because laboratory experiments and field observations are limited by their reduced ecologic complexity and sample period, respectively. In contrast, the geological record

Hydrovolcanic activity in the Central Indian Ocean Basin. Does nature mimic laboratory experiments?

Digital Repository Service at National Institute of Oceanography (India)

Iyer, S.D.; ShyamPrasad, M.; Gupta, S.M.; Charan, S.N; Mukherjee, A.D.

of Kilauea Iki, Hawaii (Heiken and Lofgren, 197 l), basaltic hydromagmatic ash (Heiken, 1972; Wohletz, 1983), basaltic microspherules from the eastern Pacific Ocean (#l 1, Table 2; Melson et al., 1988) and the basaltic microlapilli from the Pacific Ocean.... Craters, calderas and hyaloclastites on young Pacific seamounts. J. Geophys. Res. 89, 8371-8390. Blanchard, M.B., Brownlee, D.E., Bunch, T.E., Hodge, P.W.. Kyte, F.T., 1980. Meteoroid ablation spheres from deep-sea sediments. Earth Planet. Sci. Lett...

Sensitivity of the regional ocean acidification and carbonate system in Puget Sound to ocean and freshwater inputs

Directory of Open Access Journals (Sweden)

Laura Bianucci

2018-03-01

Full Text Available While ocean acidification was first investigated as a global phenomenon, coastal acidification has received significant attention in recent years, as its impacts have been felt by different socio-economic sectors (e.g., high mortality of shellfish larvae in aquaculture farms. As a region that connects land and ocean, the Salish Sea (consisting of Puget Sound and the Straits of Juan de Fuca and Georgia receives inputs from many different sources (rivers, wastewater treatment plants, industrial waste treatment facilities, etc., making these coastal waters vulnerable to acidification. Moreover, the lowering of pH in the Northeast Pacific Ocean also affects the Salish Sea, as more acidic waters get transported into the bottom waters of the straits and estuaries. Here, we use a numerical ocean model of the Salish Sea to improve our understanding of the carbonate system in Puget Sound; in particular, we studied the sensitivity of carbonate variables (e.g., dissolved inorganic carbon, total alkalinity, pH, saturation state of aragonite to ocean and freshwater inputs. The model is an updated version of our FVCOM-ICM framework, with new carbonate-system and sediment modules. Sensitivity experiments altering concentrations at the open boundaries and freshwater sources indicate that not only ocean conditions entering the Strait of Juan de Fuca, but also the dilution of carbonate variables by freshwater sources, are key drivers of the carbonate system in Puget Sound.

Seasonal carbonate chemistry covariation with temperature, oxygen, and salinity in a fjord estuary: implications for the design of ocean acidification experiments.

Science.gov (United States)

Reum, Jonathan C P; Alin, Simone R; Feely, Richard A; Newton, Jan; Warner, Mark; McElhany, Paul

2014-01-01

Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall). pCO2 exceeded the 2008-2011 mean atmospheric level (392 µatm) at all depths and seasons sampled except for the near-surface waters (Salinity, which varied little (27 to 31), was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight the wide range of carbonate chemistry conditions organisms may currently experience in this and similar coastal ecosystems.

The next generation of iron fertilization experiments in the southern Ocean

Digital Repository Service at National Institute of Oceanography (India)

Smetacek, V.; Naqvi, S.W.A.

Of the various macro-engineering schemes proposed to mitigate global warming, ocean iron fertilization (OIF) is one that could be started at short notice on relevant scales. It is based on the reasoning that adding trace amounts of iron to iron...

Calibration of Ocean Forcing with satellite Flux Estimates (COFFEE)

Science.gov (United States)

Barron, Charlie; Jan, Dastugue; Jackie, May; Rowley, Clark; Smith, Scott; Spence, Peter; Gremes-Cordero, Silvia

2016-04-01

Predicting the evolution of ocean temperature in regional ocean models depends on estimates of surface heat fluxes and upper-ocean processes over the forecast period. Within the COFFEE project (Calibration of Ocean Forcing with satellite Flux Estimates, real-time satellite observations are used to estimate shortwave, longwave, sensible, and latent air-sea heat flux corrections to a background estimate from the prior day's regional or global model forecast. These satellite-corrected fluxes are used to prepare a corrected ocean hindcast and to estimate flux error covariances to project the heat flux corrections for a 3-5 day forecast. In this way, satellite remote sensing is applied to not only inform the initial ocean state but also to mitigate errors in surface heat flux and model representations affecting the distribution of heat in the upper ocean. While traditional assimilation of sea surface temperature (SST) observations re-centers ocean models at the start of each forecast cycle, COFFEE endeavors to appropriately partition and reduce among various surface heat flux and ocean dynamics sources. A suite of experiments in the southern California Current demonstrates a range of COFFEE capabilities, showing the impact on forecast error relative to a baseline three-dimensional variational (3DVAR) assimilation using operational global or regional atmospheric forcing. Experiment cases combine different levels of flux calibration with assimilation alternatives. The cases use the original fluxes, apply full satellite corrections during the forecast period, or extend hindcast corrections into the forecast period. Assimilation is either baseline 3DVAR or standard strong-constraint 4DVAR, with work proceeding to add a 4DVAR expanded to include a weak constraint treatment of the surface flux errors. Covariance of flux errors is estimated from the recent time series of forecast and calibrated flux terms. While the California Current examples are shown, the approach is

Tracer filamentation at an unstable ocean front

Science.gov (United States)

Feng, Yen Chia; Mahadevan, Amala; Thiffeault, Jean-Luc; Yecko, Philip

2017-11-01

A front, where two bodies of ocean water with different physical properties meet, can become unstable and lead to a flow with high strain rate and vorticity. Phytoplankton and other oceanic tracers are stirred into filaments by such flow fields, as can often be seen in satellite imagery. The stretching and folding of a tracer by a two-dimensional flow field has been well studied. In the ocean, however, the vertical shear of horizontal velocity is typically two orders of magnitude larger than the horizontal velocity gradient. Theoretical calculations show that vertical shear alters the way in which horizontal strain affects the tracer, resulting in thin, sloping structures in the tracer field. Using a non-hydrostatic ocean model of an unstable ocean front, we simulate tracer filamentation to identify the effect of vertical shear on the deformation of the tracer. In a complementary laboratory experiment, we generate a simple, vertically sheared strain flow and use dye and particle image velocimetry to quantify the filamentary structures in terms of the strain and shear. We identify how vertical shear alters the tracer filaments and infer how the evolution of tracers in the ocean will differ from the idealized two-dimensional paradigm. Support of NSF DMS-1418956 is acknowledged.

A Research Experiences for Undergraduates program (REU) Program Designed to Recruit, Engage and Prepare a Diverse Student Population for Careers in Ocean Sciences.

Science.gov (United States)

Clarkston, B. E.; Garza, C.

2016-02-01

The problem of improving diversity within the Ocean Sciences workforce—still underperforming relative to other scientific disciplines—can only be addressed by first recruiting and engaging a more diverse student population into the discipline, then retaining them in the workforce. California State University, Monterey Bay (CSUMB) is home to the Monterey Bay Regional Ocean Science Research Experiences for Undergraduates (REU) program. As an HSI with strong ties to multiple regional community colleges and other Predominantly Undergraduate Institutions (PUIs) in the CSU system, the Monterey Bay REU is uniquely positioned to address the crucial recruitment and engagement of a diverse student body. Eleven sophomore and junior-level undergraduate students are recruited per year from academic institutions where research opportunities in STEM are limited and from groups historically underrepresented in the Ocean Sciences, including women, underrepresented minorities, persons with disabilities, and veterans. During the program, students engage in a 10-week original research project guided by a faculty research mentor in one of four themes: Oceanography, Marine Biology and Ecology, Ocean Engineering, and Marine Geology. In addition to research, students develop scientific self-efficacy and literacy skills through rigorous weekly professional development workshops in which they practice critical thinking, ethical decision-making, peer review, writing and oral communication skills. These workshops include tangible products such as an NSF-style proposal paper, Statement of Purpose and CV modelled for the SACNAS Travel Award Application, research abstract, scientific report and oral presentation. To help retain students in Ocean Sciences, students build community during the REU by living together in the CSUMB dormitories; post-REU, students stay connected through an online facebook group, LinkedIn page and group webinars. To date, the REU has supported 22 students in two

Ocean Literacy After-School

Science.gov (United States)

Hlinka, Lisa

2016-04-01

Ocean Literacy is a topic that is often underrepresented in secondary school science curriculum. To combat this deficit, our School has partnered up with Hudson River Community Sailing (HRCS), a local organization in New York City that offers an after-school program to high-need high school students in the surrounding community. This organization has developed a 9th grade Sail Academy which allows students from participating public high schools to increase their proficiency in math and science by learning basic sailing, navigation, and boat building. Upon successfully completing the 9th grade Sail Academy curriculum, students enter the "First Mates Program" which offers a scaffolded set of youth development experiences that prepare students for college, career, leadership, and stewardship. This program is built in the context of a new Ocean Literacy Curriculum focused around 3 major topics within Ocean Literacy: Marine Debris, Meteorology, and Ecology (specifically water quality). The learning experiences include weekly data collection of marine debris, weather conditions, and water quality testing in the Hudson River adjacent to the HRCS Boathouse. Additionally there are weekly lessons engaging students in the fundamentals of each of the 3 topics and how they are also important in the lens of sailing. During the marine debris portion of the curriculum students identify sources of marine debris, impacts on the local environment, and study how debris can travel along the ocean currents leading in to larger garbage gyres. To supplement the curriculum, students embarked on a day trip to the Newtown Creek Wastewater Treatment Facility in Brooklyn, NY to learn how and where NYC receives its drinking water, how wastewater is treated, and how water quality in the local area can be easily influenced. While on the trip, students did their data collection of marine debris, weather conditions, and water quality testing at Newtown Creek, and then they compared their results

The new version of the Institute of Numerical Mathematics Sigma Ocean Model (INMSOM) for simulation of Global Ocean circulation and its variability

Science.gov (United States)

Gusev, Anatoly; Fomin, Vladimir; Diansky, Nikolay; Korshenko, Evgeniya

2017-04-01

) Improvement river runoff algorithm accounting the total amount of discharged water. 6) Using explicit leapfrog time scheme for all lateral operators and implicit Euler scheme for vertical diffusion and viscosity. The INMSOM is tested by reproducing World Ocean circulation and thermohaline characteristics using the well-proved CORE dataset. The presentation is devoted to the analysis of new INMSOM simulation results, estimation of their quality and comparison to the ones previously obtained with the INMOM. The main aim of the INMSOM development is using it as the oceanic component of the next version of INMCM. The work was supported by the Russian Foundation for Basic Research (grants № 16-05-00534 and № 15-05-07539) References 1. Danabasoglu, G., Yeager S.G., Bailey D., et al., 2014: North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part I: Mean states. Ocean Modelling, 73, 76-107. 2. Danabasoglu, G., Yeager S.G., Kim W.M. et al., 2016: North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part II: Inter-annual to decadal variability. Ocean Modelling, 97, 65-90. 3. Downes S.M., Farneti R., Uotila P. et al. An assessment of Southern Ocean water masses and sea ice during 1988-2007 in a suite of interannual CORE-II simulations. Ocean Modelling (2015), 94, 67-94. 4. Farneti R., Downes S.M., Griffies S.M. et al. An assessment of Antarctic Circumpolar Current and Southern Ocean Meridional Overturning Circulation during 1958-2007 in a suite of interannual CORE-II simulations, Ocean Modelling (2015), 93, 84-120. 5. Gusev A.V. and Diansky N.A. Numerical simulation of the World ocean circulation and its climatic variability for 1948-2007 using the INMOM. Izvestiya, Atmospheric and Oceanic Physics, 2014, V. 50, N. 1, P. 1-12 6. Large, W., Yeager, S., 2009. The global climatology of an interannually varying air-sea flux data set. Clim Dyn, V. 33, P. 341-364. 7. Ushakov K.V., Grankina T.B., Ibraev R

Dosimetry at the Los Alamos Critical Experiments Facility: Past, present, and future

International Nuclear Information System (INIS)

Malenfant, R.E.

1993-10-01

Although the primary reason for the existence of the Los Alamos Critical Experiments Facility is to provide basic data on the physics of systems of fissile material, the physical arrangements and ability to provide sources of radiation have led to applications for all types of radiation dosimetry. In the broad definition of radiation phenomena, the facility has provided sources to evaluate biological effects, radiation shielding and transport, and measurements of basic parameters such as the evaluation of delayed neutron parameters. Within the last 15 years, many of the radiation measurements have been directed to calibration and intercomparison of dosimetry related to nuclear criticality safety. Future plans include (1) the new applications of Godiva IV, a bare-metal pulse assembly, for dosimetry (including an evaluation of neutron and gamma-ray room return); (2) a proposal to relocate the Health Physics Research Reactor from the Oak Ridge National Laboratory to Los Alamos, which will provide the opportunity to continue the application of a primary benchmark source to radiation dosimetry; and (3) a proposal to employ SHEBA, a low-enrichment solution assembly, for accident dosimetry and evaluation

Amino Acid Stability in the Early Oceans

Science.gov (United States)

Parker, E. T.; Brinton, K. L.; Burton, A. S.; Glavin, D. P.; Dworkin, J. P.; Bada, J. L.

2015-01-01

It is likely that a variety of amino acids existed in the early oceans of the Earth at the time of the origin and early evolution of life. "Primordial soup", hydrothermal vent, and meteorite based processes could have contributed to such an inventory. Several "protein" amino acids were likely present, however, based on prebiotic synthesis experiments and carbonaceous meteorite studies, non-protein amino acids, which are rare on Earth today, were likely the most abundant. An important uncertainty is the length of time these amino acids could have persisted before their destruction by abiotic and biotic processes. Prior to life, amino acid concentrations in the oceans were likely regulated by circulation through hydro-thermal vents. Today, the entire ocean circulates through vent systems every 10(exp 7) years. On the early Earth, this value was likely smaller due to higher heat flow and thus marine amino acid life-time would have been shorter. After life, amino acids in the oceans could have been assimilated by primitive organisms.

Impact of hydrothermalism on the ocean iron cycle.

Science.gov (United States)

Tagliabue, Alessandro; Resing, Joseph

2016-11-28

As the iron supplied from hydrothermalism is ultimately ventilated in the iron-limited Southern Ocean, it plays an important role in the ocean biological carbon pump. We deploy a set of focused sensitivity experiments with a state of the art global model of the ocean to examine the processes that regulate the lifetime of hydrothermal iron and the role of different ridge systems in governing the hydrothermal impact on the Southern Ocean biological carbon pump. Using GEOTRACES section data, we find that stabilization of hydrothermal iron is important in some, but not all regions. The impact on the Southern Ocean biological carbon pump is dominated by poorly explored southern ridge systems, highlighting the need for future exploration in this region. We find inter-basin differences in the isopycnal layer onto which hydrothermal Fe is supplied between the Atlantic and Pacific basins, which when combined with the inter-basin contrasts in oxidation kinetics suggests a muted influence of Atlantic ridges on the Southern Ocean biological carbon pump. Ultimately, we present a range of processes, operating at distinct scales, that must be better constrained to improve our understanding of how hydrothermalism affects the ocean cycling of iron and carbon.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'. © 2016 The Author(s).

Ocean thermal energy: concept and resources, history and perspectives

International Nuclear Information System (INIS)

Nihous, Gerard

2015-10-01

Two articles address the possibility of exploiting a higher than 20 degrees temperature difference between ocean surfaces and 1 km deep waters to produce electricity. The first article describes the operation principle in closed cycle and briefly presents the open cycle approach. The global energetic assessment is discussed. The author analyses available thermal resources in relationship with the main ocean streams. He outlines that the design of an ocean thermal energy project requires the acquisition and knowledge of a lot of data, modelling and simulations. In the second article, the author notices that past experiments highlighted the difficulties of implementation of the concept. He notably evokes works performed by Georges Claude during the 1920's, projects elaborated at the end of the 20. century, the realisation of a mini OTEC (Ocean Thermal Energy Conversion) station in Hawaii, the OTEC-1 project, a Japanese project in Nauru, the test of a suspended cold water duct, the net power producing experiment in the USA. Perspectives and costs are finally briefly discussed, and recent and promising projects briefly evoked (notably that by DCNS and Akuo Energy in Martinique)

Stable Composition of the Nano- and Picoplankton Community during the Ocean Iron Fertilization Experiment LOHAFEX

KAUST Repository

Thiele, Stefan

2014-11-17

The iron fertilization experiment LOHAFEX was conducted in a cold-core eddy in the Southern Atlantic Ocean during austral summer. Within a few days after fertilization, a phytoplankton bloom developed dominated by nano- and picoplankton groups. Unlike previously reported for other iron fertilization experiments, a diatom bloom was prevented by iron and silicate co-limitation. We used 18S rRNA gene tag pyrosequencing to investigate the diversity of these morphologically similar cell types within the nano- and picoplankton and microscopically enumerated dominant clades after catalyzed reported deposition fluorescence in situ hybridization (CARD-FISH) with specific oligonucleotide probes. In addition to Phaeocystis, members of Syndiniales group II, clade 10–11, and the Micromonas clades ABC and E made up a major fraction of the tag sequences of the nano- and picoplankton community within the fertilized patch. However, the same clades were also dominant before the bloom and outside the fertilized patch. Furthermore, only little changes in diversity could be observed over the course of the experiment. These results were corroborated by CARD-FISH analysis which confirmed the presence of a stable nano- and picoplankton community dominated by Phaeocystis and Micromonas during the entire course of the experiment. Interestingly, although Syndiniales dominated the tag sequences, they could hardly be detected by CARD-FISH, possibly due to the intracellular parasitic life style of this clade. The remarkable stability of the nano- and picoplankton community points to a tight coupling of the different trophic levels within the microbial food web during LOHAFEX.

The oceanic forecasting system near the Shimokita Peninsula, Japan

International Nuclear Information System (INIS)

In, Teiji; Nakayama, Tomoharu; Matsuura, Yasutaka; Shima, Shigeki; Ishikawa, Yoichi; Awaji, Toshiyuki; Kobayashi, Takuya; Kawamura, Hideyuki; Togawa, Orihiko; Toyoda, Takahiro

2007-01-01

The oceanic forecasting system off the Shimokita Peninsula was constructed. To evaluate the performance of this system, we carried out the hindcast experiment for the oceanic conditions in 2003. The results showed the system had good reproducibility. Especially, it was able to reproduce the feature of seasonal variation of the Tsugaru Warm Water (TWW). We expect it has enough performance in actual forecasting. (author)

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

Science.gov (United States)

Yu, Yan

North Africa is highly vulnerable to hydrologic variability and extremes, including impacts of climate change. The current understanding of oceanic versus terrestrial drivers of North African droughts and pluvials is largely model-based, with vast disagreement among models in terms of the simulated oceanic impacts and vegetation feedbacks. Regarding oceanic impacts, the relative importance of the tropical Pacific, tropical Indian, and tropical Atlantic Oceans in regulating the North African rainfall variability, as well as the underlying mechanism, remains debated among different modeling studies. Classic theory of land-atmosphere interactions across the Sahel ecotone, largely based on climate modeling experiments, has promoted positive vegetation-rainfall feedbacks associated with a dominant surface albedo mechanism. However, neither the proposed positive vegetation-rainfall feedback with its underlying albedo mechanism, nor its relative importance compared with oceanic drivers, has been convincingly demonstrated up to now using observational data. Here, the multivariate Generalized Equilibrium Feedback Assessment (GEFA) is applied in order to identify the observed oceanic and terrestrial drivers of North African climate and quantify their impacts. The reliability of the statistical GEFA method is first evaluated against dynamical experiments within the Community Earth System Model (CESM). In order to reduce the sampling error caused by short data records, the traditional GEFA approach is refined through stepwise GEFA, in which unimportant forcings are dropped through stepwise selection. In order to evaluate GEFA's reliability in capturing oceanic impacts, the atmospheric response to a sea-surface temperature (SST) forcing across the tropical Pacific, tropical Indian, and tropical Atlantic Ocean is estimated independently through ensembles of dynamical experiments and compared with GEFA-based assessments. Furthermore, GEFA's performance in capturing terrestrial

A Field Course in Ocean Sciences that Emphasizes Sustainabilty

Science.gov (United States)

Macko, S. A.; O'Connell, M. T.

2016-12-01

Sustainability awareness is increasingly a subject in educational settings. Marine science classes are perfect settings of establishing sustainability awareness owing to declining populations of organisms and perceived collapse in fisheries worldwide. Students in oceanography classes often request more direct exposure to actual ocean situations or field trips. During regular session (18 week) or shorter term (4 week) summer classes such long trips are logistically difficult owing to large numbers of students involved or timing. This approach, to use a field basis for a course supplement addresses the requests by utilizing local resources and trips for a limited number of students (20) to locations in which Ocean experiences are available, and are often supported through education and outreach components. The vision of the class was a mixture of classroom time, readings, along with paper and laboratories. In addition, short day-long trips to locations where the ocean was "captured" were also used to supplement the experience as well as speakers involved with aquaculture. Central Virginia is a fortunate location for such a class, with close access for travel to the Chesapeake Bay and numerous field stations, museums with ocean-based exhibits (the Smithsonian and NOAA) that address both extant and extinct Earth history, as well as national/state aquaria in Baltimore and Virginia Beach. Furthermore, visits to local seafood markets at local stores, or larger city markets in Washington, Baltimore and Virginia Beach and International distribution centers, enhanced the understanding of productivity in the ocean, and viability of the fisheries sustainability. The course could then address not only the particulars of the marine science, but also aspects of sustainability with discussions on ethics, including keeping animals in captivity or overfishing of particular species and the special difficulties that arise from captive or culturing ocean populations. In addition, the

Ocean FEST (Families Exploring Science Together)

Science.gov (United States)

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

2009-12-01

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

Simulating the Oceanic Migration of Silver Japanese Eels.

Directory of Open Access Journals (Sweden)

Yu-Lin Chang

Full Text Available The oceanic migration of silver Japanese eels starts from their continental growth habitats in East Asia and ends at the spawning area near the West Mariana Ridge seamount chain. However, the actual migration routes remain unknown. In this study, we examined the possible oceanic migration routes and strategies of silver Japanese eels using a particle tracking method in which virtual eels (v-eels were programmed to move vertically and horizontally in an ocean circulation model (Japan Coastal Ocean Predictability Experiment 2, JCOPE2. Four horizontal swimming strategies were tested: random heading, true navigation (readjusted heading, orientation toward the spawning area (fixed heading, and swimming against the Kuroshio. We found that all strategies, except random swimming, allowed v-eels swimming at 0.65 m s-1 to reach the spawning area within eight months after their departure from the south coast of Japan (end of the spawning season. The estimated minimum swimming speed required to reach the area spawning within eight months was 0.1 m s-1 for true navigation, 0.12 m s-1 for constant compass heading, and 0.35 m s-1 for swimming against the Kuroshio. The lowest swimming speed estimated from tracked Japanese eels at sea was 0.03 m.s-1, which would not allow them to reach the spawning area within eight months, through any of the tested orientation strategies. Our numerical experiments also showed that ocean circulation significantly affected the migration of Japanese v-eels. A strong Kuroshio could advect v-eels further eastward. In addition, western Pacific ocean currents accelerated the migration of navigating v-eels. The migration duration was shortened in years with a stronger southward flow, contributed by a stronger recirculation south of Japan, an enhanced subtropical gyre, or a higher southward Kuroshio velocity.

Simulating the Oceanic Migration of Silver Japanese Eels.

Science.gov (United States)

Chang, Yu-Lin; Miyazawa, Yasumasa; Béguer-Pon, Mélanie

2016-01-01

The oceanic migration of silver Japanese eels starts from their continental growth habitats in East Asia and ends at the spawning area near the West Mariana Ridge seamount chain. However, the actual migration routes remain unknown. In this study, we examined the possible oceanic migration routes and strategies of silver Japanese eels using a particle tracking method in which virtual eels (v-eels) were programmed to move vertically and horizontally in an ocean circulation model (Japan Coastal Ocean Predictability Experiment 2, JCOPE2). Four horizontal swimming strategies were tested: random heading, true navigation (readjusted heading), orientation toward the spawning area (fixed heading), and swimming against the Kuroshio. We found that all strategies, except random swimming, allowed v-eels swimming at 0.65 m s-1 to reach the spawning area within eight months after their departure from the south coast of Japan (end of the spawning season). The estimated minimum swimming speed required to reach the area spawning within eight months was 0.1 m s-1 for true navigation, 0.12 m s-1 for constant compass heading, and 0.35 m s-1 for swimming against the Kuroshio. The lowest swimming speed estimated from tracked Japanese eels at sea was 0.03 m.s-1, which would not allow them to reach the spawning area within eight months, through any of the tested orientation strategies. Our numerical experiments also showed that ocean circulation significantly affected the migration of Japanese v-eels. A strong Kuroshio could advect v-eels further eastward. In addition, western Pacific ocean currents accelerated the migration of navigating v-eels. The migration duration was shortened in years with a stronger southward flow, contributed by a stronger recirculation south of Japan, an enhanced subtropical gyre, or a higher southward Kuroshio velocity.

Impact of ocean model resolution on CCSM climate simulations

Energy Technology Data Exchange (ETDEWEB)

Kirtman, Ben P.; Rousset, Clement; Siqueira, Leo [University of Miami, Rosenstiel School for Marine and Atmospheric Science, Coral Gables, FL (United States); Bitz, Cecilia [University of Washington, Department of Atmospheric Science, Seattle, WA (United States); Bryan, Frank; Dennis, John; Hearn, Nathan; Loft, Richard; Tomas, Robert; Vertenstein, Mariana [National Center for Atmospheric Research, Boulder, CO (United States); Collins, William [University of California, Berkeley, Berkeley, CA (United States); Kinter, James L.; Stan, Cristiana [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); George Mason University, Fairfax, VA (United States)

2012-09-15

The current literature provides compelling evidence suggesting that an eddy-resolving (as opposed to eddy-permitting or eddy-parameterized) ocean component model will significantly impact the simulation of the large-scale climate, although this has not been fully tested to date in multi-decadal global coupled climate simulations. The purpose of this paper is to examine how resolved ocean fronts and eddies impact the simulation of large-scale climate. The model used for this study is the NCAR Community Climate System Model version 3.5 (CCSM3.5) - the forerunner to CCSM4. Two experiments are reported here. The control experiment is a 155-year present-day climate simulation using a 0.5 atmosphere component (zonal resolution 0.625 meridional resolution 0.5 ; land surface component at the same resolution) coupled to ocean and sea-ice components with zonal resolution of 1.2 and meridional resolution varying from 0.27 at the equator to 0.54 in the mid-latitudes. The second simulation uses the same atmospheric and land-surface models coupled to eddy-resolving 0.1 ocean and sea-ice component models. The simulations are compared in terms of how the representation of smaller scale features in the time mean ocean circulation and ocean eddies impact the mean and variable climate. In terms of the global mean surface temperature, the enhanced ocean resolution leads to a ubiquitous surface warming with a global mean surface temperature increase of about 0.2 C relative to the control. The warming is largest in the Arctic and regions of strong ocean fronts and ocean eddy activity (i.e., Southern Ocean, western boundary currents). The Arctic warming is associated with significant losses of sea-ice in the high-resolution simulation. The sea surface temperature gradients in the North Atlantic, in particular, are better resolved in the high-resolution model leading to significantly sharper temperature gradients and associated large-scale shifts in the rainfall. In the extra-tropics, the

The Active Role of the Ocean in the Temporal Evolution of Climate Sensitivity

Science.gov (United States)

Garuba, Oluwayemi A.; Lu, Jian; Liu, Fukai; Singh, Hansi A.

2018-01-01

The temporal evolution of the effective climate sensitivity is shown to be influenced by the changing pattern of sea surface temperature (SST) and ocean heat uptake (OHU), which in turn have been attributed to ocean circulation changes. A set of novel experiments are performed to isolate the active role of the ocean by comparing a fully coupled CO2 quadrupling community Earth System Model (CESM) simulation against a partially coupled one, where the effect of the ocean circulation change and its impact on surface fluxes are disabled. The active OHU is responsible for the reduced effective climate sensitivity and weaker surface warming response in the fully coupled simulation. The passive OHU excites qualitatively similar feedbacks to CO2 quadrupling in a slab ocean model configuration due to the similar SST spatial pattern response in both experiments. Additionally, the nonunitary forcing efficacy of the active OHU (1.7) explains the very different net feedback parameters in the fully and partially coupled responses.

Sea level variability in the eastern tropical Pacific as observed by TOPEX and Tropical Ocean-Global Atmosphere Tropical Atmosphere-Ocean Experiment

Science.gov (United States)

Giese, Benjamin S.; Carton, James A.; Holl, Lydia J.

1994-01-01

Sea surface height measurements from the TOPEX altimeter and dynamic height from Tropical Ocean-Global Atmosphere Tropical Atmosphere-Ocean (TOGA TAO) moorings are used to explore sea level variability in the northeastern tropical Pacific Ocean. Afetr the annual harmonic is removed, there are two distinct bands of variability: one band is centered at 5 deg N to 7 deg N and extends from 165 deg W to 110 deg W, and the other band is centered at 10 deg N to 12 deg N and extends from 120 deg W to the coast of Central America. The correspondence between the two independent observation data sets at 5 deg N is excellent with correlations of about 90%. The variability at 5 deg-7 deg N is identified as instability waves formed just south of the North Equatorial Countercurrent during the months of July and March. Wave amplitudes are largest in the range of longitudes 160 deg-140 deg W, where they can exceed 10 cm. The waves disappear when the equatorial current system weakens, during the months of March and May. The variability at 11 deg N in 1993 has the form of anticyclone eddies. These eddies propagate westward at a speed of about 17 cm/s, consistent with the dispersion characteristics of free Rossby waves. The eddies are shown to have their origin near the coast of central America during northern fall and winter. Their formation seems to result from intense wind bursts across the Gulfs of Tehuantepec and Papagayo which generate strong anticyclonic ocean eddies. The disappearance of the eddies in the summer of 1993 coincidences with the seasonal intensification of equatorial currents. Thus the variability at 11 deg N has very little overlap in time with the variability at 5 deg N.

Ammonium uptake by phytoplankton regulates nitrification in the sunlit ocean.

Science.gov (United States)

Smith, Jason M; Chavez, Francisco P; Francis, Christopher A

2014-01-01

Nitrification, the microbial oxidation of ammonium to nitrate, is a central part of the nitrogen cycle. In the ocean's surface layer, the process alters the distribution of inorganic nitrogen species available to phytoplankton and produces nitrous oxide. A widely held idea among oceanographers is that nitrification is inhibited by light in the ocean. However, recent evidence that the primary organisms involved in nitrification, the ammonia-oxidizing archaea (AOA), are present and active throughout the surface ocean has challenged this idea. Here we show, through field experiments coupling molecular genetic and biogeochemical approaches, that competition for ammonium with phytoplankton is the strongest regulator of nitrification in the photic zone. During multiday experiments at high irradiance a single ecotype of AOA remained active in the presence of rapidly growing phytoplankton. Over the course of this three day experiment, variability in the intensity of competition with phytoplankton caused nitrification rates to decline from those typical of the lower photic zone (60 nmol L-1 d-1) to those in well-lit layers (ammonium than they are by light itself. This finding advances our ability to model the impact of nitrification on estimates of new primary production, and emphasizes the need to more strongly consider the effects of organismal interactions on nutrient standing stocks and biogeochemical cycling in the surface of the ocean.

Coral Carbonic Anhydrases: Regulation by Ocean Acidification.

Science.gov (United States)

Zoccola, Didier; Innocenti, Alessio; Bertucci, Anthony; Tambutté, Eric; Supuran, Claudiu T; Tambutté, Sylvie

2016-06-03

Global change is a major threat to the oceans, as it implies temperature increase and acidification. Ocean acidification (OA) involving decreasing pH and changes in seawater carbonate chemistry challenges the capacity of corals to form their skeletons. Despite the large number of studies that have investigated how rates of calcification respond to ocean acidification scenarios, comparatively few studies tackle how ocean acidification impacts the physiological mechanisms that drive calcification itself. The aim of our paper was to determine how the carbonic anhydrases, which play a major role in calcification, are potentially regulated by ocean acidification. For this we measured the effect of pH on enzyme activity of two carbonic anhydrase isoforms that have been previously characterized in the scleractinian coral Stylophora pistillata. In addition we looked at gene expression of these enzymes in vivo. For both isoforms, our results show (1) a change in gene expression under OA (2) an effect of OA and temperature on carbonic anhydrase activity. We suggest that temperature increase could counterbalance the effect of OA on enzyme activity. Finally we point out that caution must, thus, be taken when interpreting transcriptomic data on carbonic anhydrases in ocean acidification and temperature stress experiments, as the effect of these stressors on the physiological function of CA will depend both on gene expression and enzyme activity.

Coral Carbonic Anhydrases: Regulation by Ocean Acidification

Directory of Open Access Journals (Sweden)

Didier Zoccola

2016-06-01

Full Text Available Global change is a major threat to the oceans, as it implies temperature increase and acidification. Ocean acidification (OA involving decreasing pH and changes in seawater carbonate chemistry challenges the capacity of corals to form their skeletons. Despite the large number of studies that have investigated how rates of calcification respond to ocean acidification scenarios, comparatively few studies tackle how ocean acidification impacts the physiological mechanisms that drive calcification itself. The aim of our paper was to determine how the carbonic anhydrases, which play a major role in calcification, are potentially regulated by ocean acidification. For this we measured the effect of pH on enzyme activity of two carbonic anhydrase isoforms that have been previously characterized in the scleractinian coral Stylophora pistillata. In addition we looked at gene expression of these enzymes in vivo. For both isoforms, our results show (1 a change in gene expression under OA (2 an effect of OA and temperature on carbonic anhydrase activity. We suggest that temperature increase could counterbalance the effect of OA on enzyme activity. Finally we point out that caution must, thus, be taken when interpreting transcriptomic data on carbonic anhydrases in ocean acidification and temperature stress experiments, as the effect of these stressors on the physiological function of CA will depend both on gene expression and enzyme activity.

Fritz Schott's Contributions to the Understanding of the Ocean Circulation

Science.gov (United States)

Visbeck, M.

2009-04-01

The ocean circulation and its central significance for global climate lay at the heart of Fritz's research. In the context of hard-won data from his more than 30 research cruises to key regions of the Atlantic and Indian oceans, he made fundamental contributions to our understanding of the wind-driven and thermohaline ocean circulation. His insights and explorations of circulation and dynamics of the tropical Indian and Atlantic Oceans have led the field and provided a large part of the basis for planning large, international experiments. Fritz's work is also distinguished by his making exceptional use of modeling results, increasingly as the models have improved. His research has provided a much clearer correspondence between the observed ocean-structure and dynamical theory-noting both theoretical successes and limitations. Besides his general interest in the physical oceanography of the World Oceans, most of his research was devoted to the dynamics of tropical oceans with its intense and highly variable current systems. Concerning the Indian Ocean, Fritz's investigated the response of the Somali Current system to the variable monsoon winds in the early 1980's, obtaining high-quality, hydrographic surveys and the first long term direct measurement of ocean currents from moored arrays. His analyses and interpretations provided a synthesis of the complex circulations there. In the tropical Atlantic Ocean Fritz research focused on the western boundary circulation with important contributions to the understanding of the North Brazil Current retroflection, and the variability of the shallow and deep western boundary currents. Trying to solve the fundamental question ‘what is the role of the tropical ocean for climate variability', Fritz initiated large multinational research programs under the umbrella of the World Climate Research Projects WOCE (World Ocean Circulation Experiment) and CLIVAR (Climate Variability and Predictability). Fritz was the initiator and

The Eddington approximation calculation of radiation flux in the atmosphere–ocean system

International Nuclear Information System (INIS)

Shi, Chong; Nakajima, Teruyuki

2015-01-01

An analytical approximation method is presented to calculate the radiation flux in the atmosphere–ocean system using the Eddington approximation when the upwelling radiation from the ocean body is negligibly small. Numerical experiments were carried out to investigate the feasibility of the method in two cases: flat and rough ocean surfaces. The results show good consistency for the reflectivity at the top of atmosphere and transmissivity just above the ocean surface, in comparison with the exact values calculated by radiative transfer models in each case. Moreover, an obvious error might be introduced for the calculation of radiation flux at larger solar zenith angles when the roughness of the ocean surface is neglected. - Highlights: • The Eddington approximation method is extended to the atmosphere–ocean system. • The roughness of ocean surface cannot be neglected at lager solar zenith angles. • Unidirectional reflectivity for rough ocean surface is proposed

Experiences of ocean literacy with different users of operational oceanography services and with high school students

Science.gov (United States)

Agostini, Paola; Coppini, Giovanni; Martinelli, Sara; Bonarelli, Roberto; Lecci, Rita; Pinardi, Nadia; Cretì, Sergio; Turrisi, Giuseppe; Ciliberti, Stefania Angela; Federico, Ivan; Mannarini, Gianandrea; Verri, Giorgia; Jansen, Eric; Lusito, Letizia; Macchia, Francesca; Montagna, Fabio; Buonocore, Mauro; Marra, Palmalisa; Tedesco, Luca; Cavallo, Arturo

2017-04-01

According to a common definition, ocean literacy is an understanding of the ocean's influence on people and people influence on the ocean. An ocean-literate person is able to make informed and responsible decisions regarding the ocean and its resources. To this aim, this paper presents operational oceanographic tools developed to meet the needs of different users, and activities performed in collaboration with high school students to support new developments of the same tools. Operational oceanography allows to deal with societal challenges such as maritime safety, coastal and marine environment management, climate change assessment and marine resources management. Oceanographic products from the European Copernicus Marine Monitoring Service - CMEMS are transformed and communicated to public and stakeholders through adding-value chains (downstreaming), which consider advanced visualization, usage of multi-channels technological platforms and specific models and algorithms. Sea Situational Awareness is strategically important for management and safety purposes of any marine domain and, in particular, the Mediterranean Sea and its coastal areas. Examples of applications for sea situational awareness and maritime safety are here presented, through user-friendly products available both by web and mobile channels (that already reach more than 100.000 users in the Mediterranean area). Further examples of ocean literacy are web bulletins used to communicate the technical contents and information related to oceanographic forecasts to a wide public. They are the result of a collaboration with high school students, with whom also other activities on improving products visualization and online communication have been performed.

Public affairs events at Ocean Sciences Meeting

Science.gov (United States)

Uhlenbrock, Kristan

2012-02-01

AGU public affairs will be cohosting two special events at Ocean Sciences 2012 that offer scientists opportunities to expand their communication, policy, and media experience. Join the conversations that highlight two important topics to connect science to society.

Satellite-based Calibration of Heat Flux at the Ocean Surface

Science.gov (United States)

Barron, C. N.; Dastugue, J. M.; May, J. C.; Rowley, C. D.; Smith, S. R.; Spence, P. L.; Gremes-Cordero, S.

2016-02-01

Model forecasts of upper ocean heat content and variability on diurnal to daily scales are highly dependent on estimates of heat flux through the air-sea interface. Satellite remote sensing is applied to not only inform the initial ocean state but also to mitigate errors in surface heat flux and model representations affecting the distribution of heat in the upper ocean. Traditional assimilation of sea surface temperature (SST) observations re-centers ocean models at the start of each forecast cycle. Subsequent evolution depends on estimates of surface heat fluxes and upper-ocean processes over the forecast period. The COFFEE project (Calibration of Ocean Forcing with satellite Flux Estimates) endeavors to correct ocean forecast bias through a responsive error partition among surface heat flux and ocean dynamics sources. A suite of experiments in the southern California Current demonstrates a range of COFFEE capabilities, showing the impact on forecast error relative to a baseline three-dimensional variational (3DVAR) assimilation using Navy operational global or regional atmospheric forcing. COFFEE addresses satellite-calibration of surface fluxes to estimate surface error covariances and links these to the ocean interior. Experiment cases combine different levels of flux calibration with different assimilation alternatives. The cases may use the original fluxes, apply full satellite corrections during the forecast period, or extend hindcast corrections into the forecast period. Assimilation is either baseline 3DVAR or standard strong-constraint 4DVAR, with work proceeding to add a 4DVAR expanded to include a weak constraint treatment of the surface flux errors. Covariance of flux errors is estimated from the recent time series of forecast and calibrated flux terms. While the California Current examples are shown, the approach is equally applicable to other regions. These approaches within a 3DVAR application are anticipated to be useful for global and larger

Ammonium uptake by phytoplankton regulates nitrification in the sunlit ocean.

Directory of Open Access Journals (Sweden)

Jason M Smith

Full Text Available Nitrification, the microbial oxidation of ammonium to nitrate, is a central part of the nitrogen cycle. In the ocean's surface layer, the process alters the distribution of inorganic nitrogen species available to phytoplankton and produces nitrous oxide. A widely held idea among oceanographers is that nitrification is inhibited by light in the ocean. However, recent evidence that the primary organisms involved in nitrification, the ammonia-oxidizing archaea (AOA, are present and active throughout the surface ocean has challenged this idea. Here we show, through field experiments coupling molecular genetic and biogeochemical approaches, that competition for ammonium with phytoplankton is the strongest regulator of nitrification in the photic zone. During multiday experiments at high irradiance a single ecotype of AOA remained active in the presence of rapidly growing phytoplankton. Over the course of this three day experiment, variability in the intensity of competition with phytoplankton caused nitrification rates to decline from those typical of the lower photic zone (60 nmol L-1 d-1 to those in well-lit layers (<1 nmol L-1 d-1. During another set of experiments, nitrification rates exhibited a diel periodicity throughout much of the photic zone, with the highest rates occurring at night when competition with phytoplankton is lowest. Together, the results of our experiments indicate that nitrification rates in the photic zone are more strongly regulated by competition with phytoplankton for ammonium than they are by light itself. This finding advances our ability to model the impact of nitrification on estimates of new primary production, and emphasizes the need to more strongly consider the effects of organismal interactions on nutrient standing stocks and biogeochemical cycling in the surface of the ocean.

Experimentally Testing Hydrothermal Vent Origin of Life on Enceladus and Other Icy/Ocean Worlds.

Science.gov (United States)

Barge, Laura M; White, Lauren M

2017-09-01

We review various laboratory strategies and methods that can be utilized to simulate prebiotic processes and origin of life in hydrothermal vent systems on icy/ocean worlds. Crucial steps that could be simulated in the laboratory include simulations of water-rock chemistry (e.g., serpentinization) to produce hydrothermal fluids, the types of mineral catalysts and energy gradients produced in vent interfaces where hydrothermal fluids interface with the surrounding seawater, and simulations of biologically relevant chemistry in flow-through gradient systems (i.e., far-from-equilibrium experiments). We describe some examples of experimental designs in detail, which are adaptable and could be used to test particular hypotheses about ocean world energetics or mineral/organic chemistry. Enceladus among the ocean worlds provides an ideal test case, since the pressure at the ocean floor is more easily simulated in the lab. Results for Enceladus could be extrapolated with further experiments and modeling to understand other ocean worlds. Key Words: Enceladus-Ocean worlds-Icy worlds-Hydrothermal vent-Iron sulfide-Gradient. Astrobiology 17, 820-833.

Effects of ocean acidification on phytoplankton physiology and nutrition for fishery-based food webs from laboratory experiment studies from 2011-05-31 to 2013-02-07 (NODC Accession 0121255)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of elevated levels of CO2 on phytoplankton physiology and...

Origin of the ``Ocean Bible"

Science.gov (United States)

Munk, W. H.

2002-12-01

``The Oceans" is such a landmark for Sverdrup and the Scripps Institution that one ought to take a look at how it came about. The book came very close to NOT being written. Sverdrup was about to decline an invitation by Prentice Hall when his secretary persuaded him to accept. The contract called for 500-600 pages, it ended up with 1087 pages. Royalty was 10% (\\$0.27 to each author for the copy I purchased in 1943). Sverdrup had estimated a market of 550 copies. By the end of 1965 23,766 copies of the American edition alone had been sold. The book was completed in the early war years under very trying conditions for Sverdrup personally. When it did appear in print, a year after Pearl Harbor, the distribution was restricted to the continental United States because ``...it would be of great aid to the enemy should it fall into his hands." The book carries the mark of Sverdrup's lifelong emphasis on the synthesis of observations: ``we have preferred definite statements to mere enumeration of uncorrelated observations and conflicting interpretations." The result was a coherent presentation of ocean science, a remarkable achievement considering how badly the ocean was undersampled. I will describe my experience as a willing listener while Sverdrup was contemplating of how to organize Chapter XV: The Water Masses and Currents of the Oceans.

Single photon light detector for deep ocean applications

International Nuclear Information System (INIS)

Matsuno, S.; Babson, J.; Learned, J.G.; O'Connor, D.; Grieder, P.K.F.; Wilson, C.

1989-01-01

We have developed a single photon sensitive light detector module which can be operated in the ocean to a depth of 5000 m. It was designed primarily to be used as a Cherenkov light detector in conjunction with the DUMAND (Deep Underwater Muon And Neutrino Detector) experiment. After calibration in the laboratory, seven detectors, assembled in a vertical string geometry, have been operated simultaneously in the deep ocean off the coast of the island of Hawaii. Cosmic ray muons have been recorded successfully at dephts ranging from 2000 to 4000 m. The results have demonstrated the capability of the detector; it fulfills the specifications required for the modules to be used in a deep ocean muon and neutrino detector. (orig.)

Studying ocean acidification in the Arctic Ocean

Science.gov (United States)

Robbins, Lisa

2012-01-01

The U.S. Geological Survey (USGS) partnership with the U.S. Coast Guard Ice Breaker Healey and its United Nations Convention Law of the Sea (UNCLOS) cruises has produced new synoptic data from samples collected in the Arctic Ocean and insights into the patterns and extent of ocean acidification. This framework of foundational geochemical information will help inform our understanding of potential risks to Arctic resources due to ocean acidification.

Calibration, characterization, and first results with the Ocean PHILLS hyperspectral imager

Science.gov (United States)

Davis, Curtiss O.; Kappus, Mary E.; Bowles, Jeffrey H.; Fisher, John; Antoniades, John A.; Carney, Megan

1999-10-01

The Ocean Portable Hyperspectral Imager for Low-Light spectroscopy (Ocean PHILLS), is a new hyperspectral imager specifically designed for imaging the coastal ocean. It uses a thinned, backside illuminated CCD for high sensitivity, and an all-reflective spectrograph with a convex grating in an Offner configuration to produce a distortion free image. Here we describe the instrument design and present the results of laboratory calibration and characterization and example results from a two week field experiment imaging the coastal waters off Lee Stocking, Island, Bahamas.

Ocean Acidification: Hands-On Experiments to Explore the Causes and Consequences

Science.gov (United States)

Bruno, Barbara C.; Tice, Kimberly A.; Puniwai, Noelani; Achilles, Kate

2011-01-01

Ocean acidification is one of the most serious environmental issues facing the planet (e.g., Doney 2006; Guinotte and Fabry 2009). It is caused by excess carbon dioxide (CO[subscript 2]) in the atmosphere. Human activities such as burning fossil fuels put CO[subscript 2] and other heat-trapping gases into the atmosphere, which causes the Earth's…

Ocean tides

Science.gov (United States)

Hendershott, M. C.

1975-01-01

A review of recent developments in the study of ocean tides and related phenomena is presented. Topics briefly discussed include: the mechanism by which tidal dissipation occurs; continental shelf, marginal sea, and baroclinic tides; estimation of the amount of energy stored in the tide; the distribution of energy over the ocean; the resonant frequencies and Q factors of oceanic normal modes; the relationship of earth tides and ocean tides; and numerical global tidal models.

Effects of ocean acidification on growth and otolith condition of juvenile scup, Stenotomus chrysops from laboratory experiment studies from 2011-08-24 to 2011-10-19 (NODC Accession 0117506)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of elevated levels of CO2 on the growth, survival, otolith (ear...

Mediterranean climate change and Indian Ocean warming

International Nuclear Information System (INIS)

Hoerling, M.; Eischeid, J.; Hurrel, J.

2006-01-01

General circulation model (GCM) responses to 20. century changes in sea surface temperatures (SSTs) and greenhouse gases are diagnosed, with emphasis on their relationship to observed regional climate change over the Mediterranean region. A major question is whether the Mediterranean region's drying trend since 1950 can be understood as a consequence of the warming trend in tropical SSTs. We focus on the impact of Indian Ocean warming, which is itself the likely result of increasing greenhouse gases. It is discovered that a strong projection onto the positive polarity of the North Atlantic Oscillation (NAO) index characterizes the atmospheric response structure to the 1950-1999 warming of Indian Ocean SSTs. This influence appears to be robust in so far as it is reproduced in ensembles of experiments using three different GCMs. Both the equilibrium and transient responses to Indian Ocean warming are examined. Under each scenario, the latitude of prevailing mid latitude westerlies shifts poleward during the November-April period. The consequence is a drying of the Mediterranean region, whereas northern Europe and Scandinavia receive increased precipitation in concert with the poleward shift of storminess. The IPCC (TAR) 20. century coupled ocean-atmosphere simulations forced by observed greenhouse gas changes also yield a post-1950 drying trend over the Mediterranean. We argue that this feature of human-induced regional climate change is the outcome of a dynamical feedback, one involving Indian Ocean warming and a requisite adjustment of atmospheric circulation systems to such ocean warming

Plane-parallel biases computed from inhomogeneous Arctic clouds and sea ice

Science.gov (United States)

Rozwadowska, Anna; Cahalan, Robert F.

2002-10-01

Monte Carlo simulations of the expected influence of nonuniformity in cloud structure and surface albedo on shortwave radiative fluxes in the Arctic atmosphere are presented. In particular, plane-parallel biases in cloud albedo and transmittance are studied for nonabsorbing, low-level, all-liquid stratus clouds over sea ice. The "absolute bias" is defined as the difference between the cloud albedo or transmittance for the uniform or plane-parallel case, and the albedo or transmittance for nonuniform conditions with the same mean cloud optical thickness and the same mean surface albedo, averaged over a given area (i.e., bias > 0 means plane-parallel overestimates). Ranges of means and standard deviations of input parameters typical of Arctic conditions are determined from the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment Artic Cloud Experiment (FIRE/ACE)/Surface Heat Budget of the Arctic Ocean (SHEBA)/Atmospheric Radiation Measurement Program (ARM) experiment, a cooperative effort of the Department of Energy, NASA, NSF, the National Oceanic and Atmospheric Administration, the Office of Naval Research, and the Atmospheric Environment Service. We determine the sensitivity of the bias with respect to the following: domain averaged means and spatial variances of cloud optical thickness and surface albedo, shape of the surface reflectance function, presence of a scattering layer under the clouds, and solar zenith angle. The simulations show that the biases in Arctic conditions are generally lower than in subtropical stratocumulus. The magnitudes of the absolute biases are unlikely to exceed 0.02 for albedo and 0.05 for transmittance. The "relative bias" expresses the absolute bias as a percentage of the actual cloud albedo or transmittance. The magnitude of the relative bias in albedo is typically below 2% over the reflective Arctic surface, while the magnitude of the relative bias in transmittance can exceed 10%.

Modeling study on nuclide transport in ocean - an ocean compartment method

International Nuclear Information System (INIS)

Lee, Youn Myoung; Suh, Kyung Suk; Han, Kyoung Won

1991-01-01

An ocean compartment model simulating transport of nuclides by advection due to ocean circulation and interaction with suspended sediments is developed, by which concentration breakthrough curves of nuclides can be calculated as a function of time. Dividing ocean into arbitrary number of characteristic compartments and performing a balance of mass of nuclides in each ocean compartment, the governing equation for the concentration in the ocean is obtained and a solution by the numerical integration is obtained. The integration method is specially useful for general stiff systems. For transfer coefficients describing advective transport between adjacent compartments by ocean circulation, the ocean turnover time is calculated by a two-dimensional numerical ocean method. To exemplify the compartment model, a reference case calculation for breakthrough curves of three nuclides in low-level radioactive wastes, Tc-99, Cs-137, and Pu-238 released from hypothetical repository under the seabed is carried out with five ocean compartments. Sensitivity analysis studies for some parameters to the concentration breakthrough curves are also made, which indicates that parameters such as ocean turnover time and ocean water volume of compartments have an important effect on the breakthrough curves. (Author)

Temperature profile data collected using XBT from the CHAIN from the Atlantic Ocean during the International Decade of Ocean Exploration / Mid-Ocean Dynamics Experiment (IDOE/MODE) project, 1975-01-22 to 1975-02-02 (NODC Accession 7601423)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from CHAIN in the Atlantic Ocean from January 22, 1975 to February 2, 1975. Data were...

Dispersion and Cluster Scales in the Ocean

Science.gov (United States)

Kirwan, A. D., Jr.; Chang, H.; Huntley, H.; Carlson, D. F.; Mensa, J. A.; Poje, A. C.; Fox-Kemper, B.

2017-12-01

Ocean flow space scales range from centimeters to thousands of kilometers. Because of their large Reynolds number these flows are considered turbulent. However, because of rotation and stratification constraints they do not conform to classical turbulence scaling theory. Mesoscale and large-scale motions are well described by geostrophic or "2D turbulence" theory, however extending this theory to submesoscales has proved to be problematic. One obvious reason is the difficulty in obtaining reliable data over many orders of magnitude of spatial scales in an ocean environment. The goal of this presentation is to provide a preliminary synopsis of two recent experiments that overcame these obstacles. The first experiment, the Grand LAgrangian Deployment (GLAD) was conducted during July 2012 in the eastern half of the Gulf of Mexico. Here approximately 300 GPS-tracked drifters were deployed with the primary goal to determine whether the relative dispersion of an initially densely clustered array was driven by processes acting at local pair separation scales or by straining imposed by mesoscale motions. The second experiment was a component of the LAgrangian Submesoscale Experiment (LASER) conducted during the winter of 2016. Here thousands of bamboo plates were tracked optically from an Aerostat. Together these two deployments provided an unprecedented data set on dispersion and clustering processes from 1 to 106 meter scales. Calculations of statistics such as two point separations, structure functions, and scale dependent relative diffusivities showed: inverse energy cascade as expected for scales above 10 km, a forward energy cascade at scales below 10 km with a possible energy input at Langmuir circulation scales. We also find evidence from structure function calculations for surface flow convergence at scales less than 10 km that account for material clustering at the ocean surface.

Grass Roots Design for the Ocean Science of Tomorrow

Science.gov (United States)

Jul, S.; Peach, C. L.; Kilb, D. L.; Schofield, O.; Fisher, C.; Quintana, C.; Keen, C. S.

2010-12-01

Current technologies offer the opportunity for ocean science to expand its traditional expeditionary base by embracing e-science methods of continuous interactive real-time research. The Ocean Observatories Initiative Cyberinfrastructure (OOI CI) is an NSF-funded effort to develop a national cyberinfrastructure that will allow researchers, educators and others to share in this new type of oceanography. The OOI is an environmental observatory spanning coastal waters to the deep ocean, enabled by the CI to offer scientists continuous interactive access to instruments in the ocean, and allow them to search, subscribe to and access real-time or archival data streams. It will also supply interactive analysis and visualization tools, and a virtual social environment for discovering and realizing collaborative opportunities. Most importantly, it provides an extensible open-access cyberinfrastructure that supports integration of new technologies and observatories, and which will allow adoption of its tools elsewhere, such as by the Integrated Ocean Observing System (IOOS). The eventual success of such a large and flexible system requires the input of a large number of people, and user-centered design has been a driving philosophy of the OOI CI from its beginning. Support for users’ real needs cannot be designed as an add-on or casual afterthought, but must be deeply embedded in all aspects of a project, from inception through architecture, implementation, and deployment. The OOI CI strategy is to employ the skills and knowledge of a small number of user experience professionals to channel and guide a very large collective effort to deliver tools, interfaces and interactions that are intellectually stimulating, scientifically productive, and conducive to innovation. Participation from all parts of the user community early in the design process is vital to meeting these goals. The OOI user experience team will be on hand to meet members of the Earth and ocean sciences

Evaluation of Oceanic Surface Observation for Reproducing the Upper Ocean Structure in ECHAM5/MPI-OM

Science.gov (United States)

Luo, Hao; Zheng, Fei; Zhu, Jiang

2017-12-01

Better constraints of initial conditions from data assimilation are necessary for climate simulations and predictions, and they are particularly important for the ocean due to its long climate memory; as such, ocean data assimilation (ODA) is regarded as an effective tool for seasonal to decadal predictions. In this work, an ODA system is established for a coupled climate model (ECHAM5/MPI-OM), which can assimilate all available oceanic observations using an ensemble optimal interpolation approach. To validate and isolate the performance of different surface observations in reproducing air-sea climate variations in the model, a set of observing system simulation experiments (OSSEs) was performed over 150 model years. Generally, assimilating sea surface temperature, sea surface salinity, and sea surface height (SSH) can reasonably reproduce the climate variability and vertical structure of the upper ocean, and assimilating SSH achieves the best results compared to the true states. For the El Niño-Southern Oscillation (ENSO), assimilating different surface observations captures true aspects of ENSO well, but assimilating SSH can further enhance the accuracy of ENSO-related feedback processes in the coupled model, leading to a more reasonable ENSO evolution and air-sea interaction over the tropical Pacific. For ocean heat content, there are still limitations in reproducing the long time-scale variability in the North Atlantic, even if SSH has been taken into consideration. These results demonstrate the effectiveness of assimilating surface observations in capturing the interannual signal and, to some extent, the decadal signal but still highlight the necessity of assimilating profile data to reproduce specific decadal variability.

The Experience of Using Autonomous Drifters for Studying the Ice Fields and the Ocean Upper Layer in the Arctic

Directory of Open Access Journals (Sweden)

S.V. Motyzhev

2017-04-01

Full Text Available The constructional and operational features of the BTC60/GPS/ice temperature-profiling drifters, developed in Marine Hydrophysical institute RAS for investigation of polar areas, are considered in this article. The drifters operated in completely automatic mode measuring air pressure, water temperatures at 17 depths down to 60 m, ocean pressures at 20, 40 and 60 m nominal depths and current locations. Accuracies of measurements were: +/-2 hPa for air pressure, +/-0.1°C for temperatures, +/-30 hPa for ocean pressure, 60 m for locations. Iridium satellite communication system was used for data transfer. Time delay between sample and delivery to a user did not exceed 10 minutes. More than 30 thermodrifters were developed in the Beaufort Sea – Canada Basin and central Arctic for the period from September 2012 to September 2014. Total duration of drifting buoys in operation was more of 4800 days. It was accepted the data of hourly samples about variability of ice-flows and ice field as a whole movements, thermo processes within upper water layer below ice, air pressure in near surface atmosphere of the Arctic region. The article includes some results of statistical analysis of data from drifter ID247950, the 3-year trajectory of which depended on the processes of transfer and evolution of ice fields in the Beaufort Sea – Canada Basin. Over a long period of time the Arctic buoy in-situ experiments allowed resulting about capability and reasonability to create reliable, technological and low-cost buoy network on basis of BTC60/GPS/ice drifters to monitor Arctic area of the World Ocean.

Transgenerational acclimation of fishes to climate change and ocean acidification

OpenAIRE

Munday, Philip L.

2014-01-01

There is growing concern about the impacts of climate change and ocean acidification on marine organisms and ecosystems, yet the potential for acclimation and adaptation to these threats is poorly understood. Whereas many short-term experiments report negative biological effects of ocean warming and acidification, new studies show that some marine species have the capacity to acclimate to warmer and more acidic environments across generations. Consequently, transgenerational plasticity may be...

The aluminum anode in deep ocean environments

International Nuclear Information System (INIS)

Schreiber, C.F.

1989-01-01

Results of field and mini-plant studies are presented for A1 + 0.045% Hg + 0.1% Si + 0.45% Zn* and A1 + 0.015% In + 0.1% Si + 3% Zn** anodes in varying depths of natural seawater. Current capacity and potential information are presented. In addition to information on anode current capacity and potential, polarization curves were obtained on both aluminum alloys using potentiostatic techniques at a simulated ocean depth of 1090 ft. (332 m). These data were compared with similarly run experiments at ocean surface pressures. As a basis of comparison, zinc anodes (U.S. Mil-A-18001H) were included as a companion alloy. Information gained on zinc is sufficient to accurately represent the behavior of this alloy. Results conclude that conditions of high pressure (and low temperature) associated with the alloys under test did not alter their galvanic behavior from that noted at the ocean surface

Ocean Prediction Center

Science.gov (United States)

Social Media Facebook Twitter YouTube Search Search For Go NWS All NOAA Weather Analysis & Forecasts of Commerce Ocean Prediction Center National Oceanic and Atmospheric Administration Analysis & Unified Surface Analysis Ocean Ocean Products Ice & Icebergs NIC Ice Products NAIS Iceberg Analysis

Ocean Robotic Networks

Energy Technology Data Exchange (ETDEWEB)

Schofield, Oscar [Rutgers University

2012-05-23

We live on an ocean planet which is central to regulating the Earth’s climate and human society. Despite the importance of understanding the processes operating in the ocean, it remains chronically undersampled due to the harsh operating conditions. This is problematic given the limited long term information available about how the ocean is changing. The changes include rising sea level, declining sea ice, ocean acidification, and the decline of mega fauna. While the changes are daunting, oceanography is in the midst of a technical revolution with the expansion of numerical modeling techniques, combined with ocean robotics. Operating together, these systems represent a new generation of ocean observatories. I will review the evolution of these ocean observatories and provide a few case examples of the science that they enable, spanning from the waters offshore New Jersey to the remote waters of the Southern Ocean.

Water Partitioning in Planetary Embryos and Protoplanets with Magma Oceans

Science.gov (United States)

Ikoma, M.; Elkins-Tanton, L.; Hamano, K.; Suckale, J.

2018-06-01

The water content of magma oceans is widely accepted as a key factor that determines whether a terrestrial planet is habitable. Water ocean mass is determined as a result not only of water delivery and loss, but also of water partitioning among several reservoirs. Here we review our current understanding of water partitioning among the atmosphere, magma ocean, and solid mantle of accreting planetary embryos and protoplanets just after giant collisions. Magma oceans are readily formed in planetary embryos and protoplanets in their accretion phase. Significant amounts of water are partitioned into magma oceans, provided the planetary building blocks are water-rich enough. Particularly important but still quite uncertain issues are how much water the planetary building blocks contain initially and how water goes out of the solidifying mantle and is finally degassed to the atmosphere. Constraints from both solar-system explorations and exoplanet observations and also from laboratory experiments are needed to resolve these issues.

The Ocean deserts:salt budgets of northern subtropical oceans and their

KAUST Repository

Carton, Jim

2011-04-09

The Ocean deserts: salt budgets of northern subtropical oceans and their relationship to climate variability The high salinity near surface pools of the subtropical oceans are the oceanic deserts, with high levels of evaporation and low levels of precip

Student research in criticality safety at the University of Arizona

International Nuclear Information System (INIS)

Hetrick, D.L.

1997-01-01

A very brief progress report on four University of Arizona student projects is given. Improvements were made in simulations of power pulses in aqueous solutions, including the TWODANT model. TWODANT calculations were performed to investigate the effect of assembly shape on the expansion coefficient of reactivity for solutions. Preliminary calculations were made of critical heights for the Los Alamos SHEBA assembly. Calculations to support French experiments to measure temperature coefficients of dilute plutonium solutions confirmed feasibility

Ocean acidification research in the 'post-genomic' era: Roadmaps from the purple sea urchin Strongylocentrotus purpuratus.

Science.gov (United States)

Evans, Tyler G; Padilla-Gamiño, Jacqueline L; Kelly, Morgan W; Pespeni, Melissa H; Chan, Francis; Menge, Bruce A; Gaylord, Brian; Hill, Tessa M; Russell, Ann D; Palumbi, Stephen R; Sanford, Eric; Hofmann, Gretchen E

2015-07-01

Advances in nucleic acid sequencing technology are removing obstacles that historically prevented use of genomics within ocean change biology. As one of the first marine calcifiers to have its genome sequenced, purple sea urchins (Strongylocentrotus purpuratus) have been the subject of early research exploring genomic responses to ocean acidification, work that points to future experiments and illustrates the value of expanding genomic resources to other marine organisms in this new 'post-genomic' era. This review presents case studies of S. purpuratus demonstrating the ability of genomic experiments to address major knowledge gaps within ocean acidification. Ocean acidification research has focused largely on species vulnerability, and studies exploring mechanistic bases of tolerance toward low pH seawater are comparatively few. Transcriptomic responses to high pCO₂ seawater in a population of urchins already encountering low pH conditions have cast light on traits required for success in future oceans. Secondly, there is relatively little information on whether marine organisms possess the capacity to adapt to oceans progressively decreasing in pH. Genomics offers powerful methods to investigate evolutionary responses to ocean acidification and recent work in S. purpuratus has identified genes under selection in acidified seawater. Finally, relatively few ocean acidification experiments investigate how shifts in seawater pH combine with other environmental factors to influence organism performance. In S. purpuratus, transcriptomics has provided insight into physiological responses of urchins exposed simultaneously to warmer and more acidic seawater. Collectively, these data support that similar breakthroughs will occur as genomic resources are developed for other marine species. Copyright © 2015 Elsevier Inc. All rights reserved.

Winter/Summer Monsoon Experiment

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Winter/Summer Monsoon Experiment (MONEX) was conducted during the First Global GARP (Global Atmospheric Research Program) Experiment (FGGE). An international...

Cascadia Initiative Ocean Bottom Seismograph Performance

Science.gov (United States)

Evers, B.; Aderhold, K.

2017-12-01

The Ocean Bottom Seismograph Instrument Pool (OBSIP) provided instrumentation and operations support for the Cascadia Initiative community experiment. This experiment investigated geophysical processes across the Cascadia subduction zone through a combination of onshore and offshore seismic data. The recovery of Year 4 instruments in September 2015 marked the conclusion of a multi-year experiment that utilized 60 ocean-bottom seismographs (OBSs) specifically designed for the subduction zone boundary, including shallow/deep water deployments and active fisheries. The new instruments featured trawl-resistant enclosures designed by Lamont-Doherty Earth Observatory (LDEO) and Scripps Institution of Oceanography (SIO) for shallow deployment [water depth ≤ 500 m], as well as new deep-water instruments designed by Woods Hole Oceanographic Institute (WHOI). Existing OBSIP instruments were also deployed along the Blanco Transform Fault and on the Gorda Plate through complementary experiments. Station instrumentation included weak and strong motion seismometers, differential pressure gauges (DPG) and absolute pressure gauges (APG). All data collected from the Cascadia, Blanco, and Gorda deployments is available through the Incorporated Research Institutions for Seismology (IRIS) Data Management Center (DMC). The Cascadia Initiative is the largest amphibious seismic experiment undertaken to date, encompassing a diverse technical implementation and demonstrating an effective structure for community experiments. Thus, the results from Cascadia serve as both a technical and operational resource for the development of future community experiments, such as might be contemplated as part of the SZ4D Initiative. To guide future efforts, we investigate and summarize the quality of the Cascadia OBS data using basic metrics such as instrument recovery and more advanced metrics such as noise characteristics through power spectral density analysis. We also use this broad and diverse

Temperature profile data collected using XBT casts from the CHAIN from the Atlantic Ocean during the International Decade of Ocean Exploration / Mid-Ocean Dynamics Experiment (IDOE/MODE) project, 1975-05-25 to 1975-06-07 (NODC Accession 7601261)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from CHAIN in the Atlantic Ocean from May 25, 1973 to June 7, 1973. Data were submitted...

Do swimming animals mix the ocean?

Science.gov (United States)

Dabiri, John

2013-11-01

Perhaps. The oceans are teeming with billions of swimming organisms, from bacteria to blue whales. Current research efforts in biological oceanography typically focus on the impact of the marine environment on the organisms within. We ask the opposite question: can organisms in the ocean, especially those that migrate vertically every day and regionally every year, change the physical structure of the water column? The answer has potentially important implications for ecological models at local scale and climate modeling at global scales. This talk will introduce the still-controversial prospect of biogenic ocean mixing, beginning with evidence from measurements in the field. More recent laboratory-scale experiments, in which we create controlled vertical migrations of plankton aggregations using laser signaling, provide initial clues toward a mechanism to achieve efficient mixing at scales larger than the individual organisms. These results are compared and contrasted with theoretical models, and they highlight promising avenues for future research in this area. Funding from the Office of Naval Research and the National Science Foundation is gratefully acknowledged.

Norwegian Ocean Observatory Network (NOON)

Science.gov (United States)

Ferré, Bénédicte; Mienert, Jürgen; Winther, Svein; Hageberg, Anne; Rune Godoe, Olav; Partners, Noon

2010-05-01

The Norwegian Ocean Observatory Network (NOON) is led by the University of Tromsø and collaborates with the Universities of Oslo and Bergen, UniResearch, Institute of Marine Research, Christian Michelsen Research and SINTEF. It is supported by the Research Council of Norway and oil and gas (O&G) industries like Statoil to develop science, technology and new educational programs. Main topics relate to ocean climate and environment as well as marine resources offshore Norway from the northern North Atlantic to the Arctic Ocean. NOON's vision is to bring Norway to the international forefront in using cable based ocean observatory technology for marine science and management, by establishing an infrastructure that enables real-time and long term monitoring of processes and interactions between hydrosphere, geosphere and biosphere. This activity is in concert with the EU funded European Strategy Forum on Research Infrastructures (ESFRI) roadmap and European Multidisciplinary Seafloor Observation (EMSO) project to attract international leading research developments. NOON envisions developing towards a European Research Infrastructure Consortium (ERIC). Beside, the research community in Norway already possesses a considerable marine infrastructure that can expand towards an international focus for real-time multidisciplinary observations in times of rapid climate change. PIC The presently established cable-based fjord observatory, followed by the establishment of a cable-based ocean observatory network towards the Arctic from an O&G installation, will provide invaluable knowledge and experience necessary to make a successful larger cable-based observatory network at the Norwegian and Arctic margin (figure 1). Access to large quantities of real-time observation from the deep sea, including high definition video, could be used to provide the public and future recruits to science a fascinating insight into an almost unexplored part of the Earth beyond the Arctic Circle

Ocean for all, a different way to see oceanography

Directory of Open Access Journals (Sweden)

Bruna Ramos

2017-11-01

Full Text Available Oceanography as a science is still not very widespread in Brazilian society, making it difficult to strengthen the ties between society and the ocean. Thus, the creation of methodologies associated with new teaching techniques, improved with the help of technology, may build a more inclusive society and provide the experience of oceanographic phenomena for all. The extension project "Ocean for all", executed between March and July of 2016, performed an experience in oceanography to the elderly members of the Associação Catarinense para Integração do Cego (ACIC in Florianópolis (SC. In order to do so, a methodology was created to pass on knowledge about oceanography in its biological, geological, chemical and physical aspects to the visually impaired. During the execution of the experience, as well as the development of the methodology, problems in the coastal marine environment with anthropological origin were presented.

Ocean One: A Robotic Avatar for Oceanic Discovery

KAUST Repository

Khatib, Oussama; Yeh, Xiyang; Brantner, Gerald; Soe, Brian; Kim, Boyeon; Ganguly, Shameek; Stuart, Hannah; Wang, Shiquan; Cutkosky, Mark; Edsinger, Aaron; Mullins, Phillip; Barham, Mitchell; Voolstra, Christian R.; Salama, Khaled N.; L'Hour, Michel; Creuze, Vincent

2016-01-01

The promise of oceanic discovery has long intrigued scientists and explorers, whether with the idea of studying underwater ecology and climate change or with the hope of uncovering natural resources and historic secrets buried deep in archaeological sites. This quest to explore the oceans requires skilled human access, yet much of the oceans are inaccessible to human divers; nearly ninetenths of the ocean floor is at 1 km or deeper [1]. Accessing these depths is imperative since factors such as pollution and deep-sea trawling threaten ecology and archaeological sites. While remotely operated vehicles (ROVs) are inadequate for the task, a robotic avatar could go where humans cannot and still embody human intelligence and intentions through immersive interfaces.

Ocean One: A Robotic Avatar for Oceanic Discovery

KAUST Repository

Khatib, Oussama

2016-11-11

The promise of oceanic discovery has long intrigued scientists and explorers, whether with the idea of studying underwater ecology and climate change or with the hope of uncovering natural resources and historic secrets buried deep in archaeological sites. This quest to explore the oceans requires skilled human access, yet much of the oceans are inaccessible to human divers; nearly ninetenths of the ocean floor is at 1 km or deeper [1]. Accessing these depths is imperative since factors such as pollution and deep-sea trawling threaten ecology and archaeological sites. While remotely operated vehicles (ROVs) are inadequate for the task, a robotic avatar could go where humans cannot and still embody human intelligence and intentions through immersive interfaces.

Seasonal Carbonate Chemistry Covariation with Temperature, Oxygen, and Salinity in a Fjord Estuary: Implications for the Design of Ocean Acidification Experiments

Science.gov (United States)

Reum, Jonathan C. P.; Alin, Simone R.; Feely, Richard A.; Newton, Jan; Warner, Mark; McElhany, Paul

2014-01-01

Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall). pCO2 exceeded the 2008–2011 mean atmospheric level (392 µatm) at all depths and seasons sampled except for the near-surface waters (aragonite were widespread (Ωar<1). We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31), was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight the wide range of carbonate chemistry conditions organisms may currently experience in this and similar coastal

South Atlantic Ocean circulation: Simulation experiments with a quasi-geostrophic model and assimilation of TOPEX/POSEIDON and ERS 1 altimeter data

Science.gov (United States)

Florenchie, P.; Verron, J.

1998-10-01

Simulation experiments of South Atlantic Ocean circulations are conducted with a 1/6°, four-layered, quasi-geostrophic model. By means of a simple nudging data assimilation procedure along satellite tracks, TOPEX/POSEIDON and ERS 1 altimeter measurements are introduced into the model to control the simulation of the basin-scale circulation for the period from October 1992 to September 1994. The model circulation appears to be strongly influenced by the introduction of altimeter data, offering a consistent picture of South Atlantic Ocean circulations. Comparisons with observations show that the assimilating model successfully simulates the kinematic behavior of a large number of surface circulation components. The assimilation procedure enables us to produce schematic diagrams of South Atlantic circulation in which patterns ranging from basin-scale currents to mesoscale eddies are portrayed in a realistic way, with respect to their complexity. The major features of the South Atlantic circulation are described and analyzed, with special emphasis on the Brazil-Malvinas Confluence region, the Subtropical Gyre with the formation of frontal structures, and the Agulhas Retroflection. The Agulhas eddy-shedding process has been studied extensively. Fourteen eddies appear to be shed during the 2-year experiment. Because of their strong surface topographic signature, Agulhas eddies have been tracked continuously during the assimilation experiment as they cross the South Atlantic basin westward. Other effects of the assimilation procedure are shown, such as the intensification of the Subtropical Gyre, the appearance of a strong seasonal cycle in the Brazil Current transport, and the increase of the mean Brazil Current transport. This last result, combined with the westward oriention of the Agulhas eddies' trajectories, leads to a southward transport of mean eddy kinetic energy across 30°S.

Cosmic ray muons in the deep ocean

Energy Technology Data Exchange (ETDEWEB)

Babson, J.; Becker-Szenzy, R.; Cady, R.; Dye, S.; Gorham, P.; Learned, J.; Matsuno, S.; O' Conner, D.; Peterson, V.; Roberts, A.; Stenger, V. (Hawaii Univ., Honolulu (USA)); Barish, B. (California Inst. of Tech., Pasadena (USA)); Bradner, H. (California Univ., San Diego, La Jolla (USA)); Clem, J.; Roos, C.; Webster, M. (Vanderbilt Univ., Nashville, TN (USA)); Gaidos, J.; Wilson, C. (Purdue Univ., Lafayette, IN (USA)); Grieder, P. (Bern Univ. (Switzerland)); Kitamura, T.; Mitsui, K.; Ohashi, Y.; Okada, A. (Tokyo Univ. (Japan). Inst. for Cosmic Ray Research); Kropp, W.; Price, L.; Reines, F.; Sobel, H. (California Univ., Irvine (USA)); March, R. (Wisconsin Univ., Madison (USA)); DUMAND Collaboration

1990-03-01

A measurement of cosmic ray muon flux was obtained at ocean depths ranging from 2 km to 4 km at 500 m intervals off the West Coast of the Big Island of Hawaii. A brief description of the experiment and the results will be presented in this paper. (orig.).

GARP Atlantic Tropical Experiment

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The GARP Atlantic Tropical Experiment (GATE) was the first major international experiment of the Global Atmospheric Research Program (GARP). It was conducted over...

Evaluation of an ensemble of Arctic regional climate models

DEFF Research Database (Denmark)

Rinke, A.; Dethloff, K.; Cassano, J. J.

2006-01-01

Simulations of eight different regional climate models (RCMs) have been performed for the period September 1997-September 1998, which coincides with the Surface Heat Budget of the Arctic Ocean (SHEBA) project period. Each of the models employed approximately the same domain covering the western......, temperature, cloud cover, and long-/shortwave downward radiation between the individual model simulations are investigated. With this work, we quantify the scatter among the models and therefore the magnitude of disagreement and unreliability of current Arctic RCM simulations. Even with the relatively...... constrained experimental design we notice a considerable scatter among the different RCMs. We found the largest across-model scatter in the 2 m temperature over land, in the surface radiation fluxes, and in the cloud cover which implies a reduced confidence level for these variables....

OceanSITES format and Ocean Observatory Output harmonisation: past, present and future

Science.gov (United States)

Pagnani, Maureen; Galbraith, Nan; Diggs, Stephen; Lankhorst, Matthias; Hidas, Marton; Lampitt, Richard

2015-04-01

The Global Ocean Observing System (GOOS) initiative was launched in 1991, and was the first step in creating a global view of ocean observations. In 1999 oceanographers at the OceanObs conference envisioned a 'global system of eulerian observatories' which evolved into the OceanSITES project. OceanSITES has been generously supported by individual oceanographic institutes and agencies across the globe, as well as by the WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology (under JCOMMOPS). The project is directed by the needs of research scientists, but has a strong data management component, with an international team developing content standards, metadata specifications, and NetCDF templates for many types of in situ oceanographic data. The OceanSITES NetCDF format specification is intended as a robust data exchange and archive format specifically for time-series observatory data from the deep ocean. First released in February 2006, it has evolved to build on and extend internationally recognised standards such as the Climate and Forecast (CF) standard, BODC vocabularies, ISO formats and vocabularies, and in version 1.3, released in 2014, ACDD (Attribute Convention for Dataset Discovery). The success of the OceanSITES format has inspired other observational groups, such as autonomous vehicles and ships of opportunity, to also use the format and today it is fulfilling the original concept of providing a coherent set of data from eurerian observatories. Data in the OceanSITES format is served by 2 Global Data Assembly Centres (GDACs), one at Coriolis, in France, at ftp://ftp.ifremer.fr/ifremer/oceansites/ and one at the US NDBC, at ftp://data.ndbc.noaa.gov/data/oceansites/. These two centres serve over 26,800 OceanSITES format data files from 93 moorings. The use of standardised and controlled features enables the files held at the OceanSITES GDACs to be electronically discoverable and ensures the widest access to the data. The Ocean

Panorama 2011: Ocean renewable energies

International Nuclear Information System (INIS)

Demoulin, P.; Vinot, S.

2011-01-01

Our society is looking increasingly to renewable energy sources in the face of the energy and environmental challenges with which it is grappling. As far as ocean renewable energies are concerned, a wide range of technologies is currently being experimented with, including wind power and energy derived from waves and tidal currents. They are all at varying levels of maturity, and bring with them very different technical and economic challenges. (author)

Youth Science Ambassadors: Connecting Indigenous communities with Ocean Networks Canada tools to inspire future ocean scientists and marine resource managers

Science.gov (United States)

Pelz, M.; Hoeberechts, M.; Hale, C.; McLean, M. A.

2017-12-01

This presentation describes Ocean Networks Canada's (ONC) Youth Science Ambassador Program. The Youth Science Ambassadors are a growing network of youth in Canadian coastal communities whose role is to connect ocean science, ONC data, and Indigenous knowledge. By directly employing Indigenous youth in communities in which ONC operates monitoring equipment, ONC aims to encourage wider participation and interest in ocean science and exploration. Further, the Youth Science Ambassadors act as role models and mentors to other local youth by highlighting connections between Indigenous and local knowledge and current marine science efforts. Ocean Networks Canada, an initiative of the University of Victoria, develops, operates, and maintains cabled ocean observatory systems. These include technologies developed on the world-leading NEPTUNE and VENUS observatories as well as community observatories in the Arctic and coastal British Columbia. These observatories, large and small, enable communities, users, scientists, teachers, and students to monitor real-time and historical data from the local marine environment from anywhere on the globe. Youth Science Ambassadors are part of the Learning and Engagement team whose role includes engaging Indigenous communities and schools in ocean science through ONC's K-12 Ocean Sense education program. All of the data collected by ONC are freely available over the Internet for non-profit use, including disaster planning, community-based decision making, and education. The Youth Science Ambassadors support collaboration with Indigenous communities and schools by facilitating educational programming, encouraging participation in ocean data collection and analysis, and fostering interest in ocean science. In addition, the Youth Science Ambassadors support community collaboration in decision-making for instrument deployment locations and identify ways in which ONC can help to address any areas of concern raised by the community. This

The Ocean Literacy Campaign

Science.gov (United States)

Schoedinger, S. E.; Strang, C.

2008-12-01

"Ocean Literacy is an understanding of the ocean's influence on you and your influence on the ocean." This simple statement captures the spirit of a conceptual framework supporting ocean literacy (COSEE et al., 2005). The framework comprises 7 essential principles and 44 fundamental concepts an ocean literate person would know (COSEE et al., 2005). The framework is the result of an extensive grassroots effort to reach consensus on (1) a definition for ocean literacy and (2) an articulation of the most important concepts to be understood by ocean-literate citizen (Cava et al., 2005). In the process of reaching consensus on these "big ideas" about the ocean, what began as a series of workshops has emerged as a campaign "owned" by an ever-expanding community of individuals, organizations and networks involved in developing and promoting the framework. The Ocean Literacy Framework has provided a common language for scientists and educators working together and serves as key guidance for the ocean science education efforts. This presentation will focus on the impact this Ocean Literacy Campaign has had to date as well as efforts underway to provide additional tools to enable educators and educational policy makers to further integrate teaching and learning about the ocean and our coasts into formal K-12 education and informal education. COSEE, National Geographic Society, NOAA, College of Exploration (2005). Ocean Literacy: The Essential Principles of Ocean Sciences Grades K-12, a jointly published brochure, URL: http://www.coexploration.org/oceanliteracy/documents/OceanLitChart.pdf Cava, F., S. Schoedinger , C. Strang, and P. Tuddenham (2005). Science Content and Standards for Ocean Literacy: A Report on Ocean Literacy, URL: http://www.coexploration.org/oceanliteracy/documents/OLit2004-05_Final_Report.pdf.

Ocean acidification challenges copepod phenotypic plasticity

Science.gov (United States)

Vehmaa, Anu; Almén, Anna-Karin; Brutemark, Andreas; Paul, Allanah; Riebesell, Ulf; Furuhagen, Sara; Engström-Öst, Jonna

2016-11-01

Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ˜ 365-1231 µatm) and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm) or quality (C : N) weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

Blue ocean strategy.

Science.gov (United States)

Kim, W Chan; Mauborgne, Renée

2004-10-01

Despite a long-term decline in the circus industry, Cirque du Soleil profitably increased revenue 22-fold over the last ten years by reinventing the circus. Rather than competing within the confines of the existing industry or trying to steal customers from rivals, Cirque developed uncontested market space that made the competition irrelevant. Cirque created what the authors call a blue ocean, a previously unknown market space. In blue oceans, demand is created rather than fought over. There is ample opportunity for growth that is both profitable and rapid. In red oceans--that is, in all the industries already existing--companies compete by grabbing for a greater share of limited demand. As the market space gets more crowded, prospects for profits and growth decline. Products turn into commodities, and increasing competition turns the water bloody. There are two ways to create blue oceans. One is to launch completely new industries, as eBay did with online auctions. But it's much more common for a blue ocean to be created from within a red ocean when a company expands the boundaries of an existing industry. In studying more than 150 blue ocean creations in over 30 industries, the authors observed that the traditional units of strategic analysis--company and industry--are of limited use in explaining how and why blue oceans are created. The most appropriate unit of analysis is the strategic move, the set of managerial actions and decisions involved in making a major market-creating business offering. Creating blue oceans builds brands. So powerful is blue ocean strategy, in fact, that a blue ocean strategic move can create brand equity that lasts for decades.

Modern and ancient geochemical constraints on Proterozoic atmosphere-ocean redox evolution

Science.gov (United States)

Hardisty, D. S.; Horner, T. J.; Wankel, S. D.; Lu, Z.; Lyons, T.; Nielsen, S.

2017-12-01

A detailed understanding of the spatiotemporal oxygenation of Earth's atmosphere-ocean system through the Precambrian has important implications for the environments capable of sustaining early eukaryotic life and the evolving oxidant budget of subducted sediments. Proxy records suggest an anoxic Fe-rich deep ocean through much of the Precambrian and atmospheric and surface-ocean oxygenation that started in earnest at the Paleoproterozoic Great Oxidation Event (GOE). The marine photic zone represented the initial site of oxygen production and accumulation via cyanobacteria, yet our understanding of surface-ocean oxygen contents and the extent and timing of oxygen propagation and exchange between the atmosphere and deeper ocean are limited. Here, we present an updated perspective of the constraints on atmospheric, surface-ocean, and deep-ocean oxygen contents starting at the GOE. Our research uses the iodine content of Proterozoic carbonates as a tracer of dissolved iodate in the shallow ocean, a redox-sensitive species quantitatively reduced in modern oxygen minimum zones. We supplement our understanding of the ancient record with novel experiments examining the rates of iodate production from oxygenated marine environments based on seawater incubations. Combining new data from iodine with published shallow marine (Ce anomaly, N isotopes) and atmospheric redox proxies, we provide an integrated view of the vertical redox structure of the atmosphere and ocean across the Proterozoic.

Nuclear criticality research at the University of New Mexico

International Nuclear Information System (INIS)

Busch, R.D.

1997-01-01

Two projects at the University of New Mexico are briefly described. The university's Chemical and Nuclear Engineering Department has completed the final draft of a primer for MCNP4A, which it plans to publish soon. The primer was written to help an analyst who has little experience with the MCNP code to perform criticality safety analyses. In addition, the department has carried out a series of approach-to-critical experiments on the SHEBA-II, a UO 2 F 2 solution critical assembly at Los Alamos National Laboratory. The results obtained differed slightly from what was predicted by the TWODANT code

Ocean acidification alters fish populations indirectly through habitat modification

Science.gov (United States)

Nagelkerken, Ivan; Russell, Bayden D.; Gillanders, Bronwyn M.; Connell, Sean D.

2016-01-01

Ocean ecosystems are predicted to lose biodiversity and productivity from increasing ocean acidification. Although laboratory experiments reveal negative effects of acidification on the behaviour and performance of species, more comprehensive predictions have been hampered by a lack of in situ studies that incorporate the complexity of interactions between species and their environment. We studied CO2 vents from both Northern and Southern hemispheres, using such natural laboratories to investigate the effect of ocean acidification on plant-animal associations embedded within all their natural complexity. Although we substantiate simple direct effects of reduced predator-avoidance behaviour by fishes, as observed in laboratory experiments, we here show that this negative effect is naturally dampened when fish reside in shelter-rich habitats. Importantly, elevated CO2 drove strong increases in the abundance of some fish species through major habitat shifts, associated increases in resources such as habitat and prey availability, and reduced predator abundances. The indirect effects of acidification via resource and predator alterations may have far-reaching consequences for population abundances, and its study provides a framework for a more comprehensive understanding of increasing CO2 emissions as a driver of ecological change.

High-level radioactive waste disposal in the deep ocean

International Nuclear Information System (INIS)

Hill, H.W.

1977-01-01

A joint programme has begun between the Fisheries Laboratory, Lowestoft and the Institute of Oceanographic Sciences, Wormley to study the dispersion of radioactivity in the deep ocean arising from the possible dumping of high level waste on the sea bed in vitrified-glass form which would permit slow leakage over a long term scale. The programme consists firstly of the development of a simple diffusion/advection model for the dispersion of radioactivity in a closed and finite ocean, which overcomes many of the criticisms of the earlier model proposed by Webb and Morley. Preliminary results from this new model are comparable to those of the Webb-Morley model for radio isotopes with half-lives of 10-300 years but are considerably more restrictive outside this range, particularly for those which are much longer-lived. The second part of the programme, towards which the emphasis is directed, concerns the field programme planned to measure the advection and diffusion parameters in the deeper layers of the ocean to provide realistic input parameters to the model and increase our fundamental understanding of the environment in which the radioactive materials may be released. The first cruises of the programme will take place in late 1976 and involve deep current meter deployments and float dispersion experiments around the present NEA dump site with some sediment sampling, so that adsorption experiments can be started on typical deep sea sediments. The programme will expand the number of long-term deep moored stations over the next five years and include further float experiments, CTD profiling, and other physical oceanography. In the second half of the 5-year programme, attempts will be made to measure diffusion parameters in the deeper layers of the ocean using radioactive tracers

Organophosphorus esters in the oceans and possible relation with ocean gyres

International Nuclear Information System (INIS)

Cheng, Wenhan; Xie, Zhouqing; Blais, Jules M.; Zhang, Pengfei; Li, Ming; Yang, Chengyun; Huang, Wen; Ding, Rui; Sun, Liguang

2013-01-01

Four organophosphorus esters (OPEs) were detected in aerosol samples collected in the West Pacific, the Indian Ocean and the Southern Ocean from 2009 to 2010, suggesting their circumpolar and global distribution. In general, the highest concentrations were detected near populated regions in China, Australia and New Zealand. OPE concentrations in the Southern Ocean were about two orders of magnitude lower than those near major continents. Additionally, relatively high OPE concentrations were detected at the Antarctic Peninsula, where several scientific survey stations are located. The four OPEs investigated here are significantly correlated with each other, suggesting they may derive from the same source. In the circumpolar transect, OPE concentrations were associated with ocean gyres in the open ocean. Their concentrations were positively related with average vorticity in the sampling area suggesting that a major source of OPEs may be found in ocean gyres where plastic debris is known to accumulate. -- Highlights: •We provide OPE concentrations in aerosols in a circumpolar expedition. •We find strong anthropogenic source of OPE pollution. •We suggest potential relationship between ocean gyres and OPE pollution. -- Our work provides a circumpolar investigation on OPEs in the Southern Ocean and we suggest a possibility that ocean currents and gyres may act as important roles in global transport of OPEs

Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from XIANG YANG HONG 05 and SHI YAN 3 in the Philippine Sea, Indian Ocean and South Pacific Ocean from 1991-11-01 to 1993-11-30 (NODC Accession 9400186)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Conductivity, Temperature and Depth (CTD) and other data were collected as part of the Coupled Ocean Atmosphere Response Experiment. Data were collected from Ships...

Anomalous intraseasonal events in the thermocline ridge region of Southern Tropical Indian Ocean and their regional impacts

Science.gov (United States)

Jayakumar, A.; Gnanaseelan, C.

2012-03-01

The present study explores the mechanisms responsible for the strong intraseasonal cooling events in the Thermocline Ridge region of the southwestern Indian Ocean. Air sea interface and oceanic processes associated with Madden Julian Oscillation are studied using an Ocean General Circulation Model and satellite observations. Sensitivity experiments are designed to understand the ocean response to intraseasonal forcing with a special emphasis on 2002 cooling events, which recorded the strongest intraseasonal perturbations during the last well-observed decade. This event is characterized by anomalous Walker circulation over the tropical Indian Ocean and persistent intraseasonal heat flux anomaly for a longer duration than is typical for similar events (but without any favorable preconditioning of ocean basic state at the interannual timescale). The model heat budget analysis during 1996 to 2007 revealed an in-phase relationship between atmospheric fluxes associated with Madden Julian Oscillation and the subsurface oceanic processes during the intense cooling events of 2002. The strong convection, reduced shortwave radiation and increased evaporation have contributed to the upper ocean heat loss in addition to the slower propagation of active phase of convection, which supported the integration of longer duration of forcing. The sensitivity experiments revealed that dynamic response of ocean through entrainment at the intraseasonal timescale primarily controls the biological response during the event, with oceanic interannual variability playing a secondary role. This study further speculates the role of oceanic intraseasonal variability in the 2002 droughts over Indian subcontinent.

IAEA To Launch Centre On Ocean Acidification

International Nuclear Information System (INIS)

2012-01-01

activities which are not currently funded at national or international levels. The centre's role will be to facilitate, promote and communicate these activities related to global actions on ocean acidification, including international observation, joint platforms and facilities, collaboration between natural and social sciences, exchange of students and scientists, joint experiments, definition of best practices, open-access bibliographic database, data management, capacity building and dissemination. (IAEA)

Experiences in multiyear combined state-parameter estimation with an ecosystem model of the North Atlantic and Arctic Oceans using the Ensemble Kalman Filter

Science.gov (United States)

Simon, Ehouarn; Samuelsen, Annette; Bertino, Laurent; Mouysset, Sandrine

2015-12-01

A sequence of one-year combined state-parameter estimation experiments has been conducted in a North Atlantic and Arctic Ocean configuration of the coupled physical-biogeochemical model HYCOM-NORWECOM over the period 2007-2010. The aim is to evaluate the ability of an ensemble-based data assimilation method to calibrate ecosystem model parameters in a pre-operational setting, namely the production of the MyOcean pilot reanalysis of the Arctic biology. For that purpose, four biological parameters (two phyto- and two zooplankton mortality rates) are estimated by assimilating weekly data such as, satellite-derived Sea Surface Temperature, along-track Sea Level Anomalies, ice concentrations and chlorophyll-a concentrations with an Ensemble Kalman Filter. The set of optimized parameters locally exhibits seasonal variations suggesting that time-dependent parameters should be used in ocean ecosystem models. A clustering analysis of the optimized parameters is performed in order to identify consistent ecosystem regions. In the north part of the domain, where the ecosystem model is the most reliable, most of them can be associated with Longhurst provinces and new provinces emerge in the Arctic Ocean. However, the clusters do not coincide anymore with the Longhurst provinces in the Tropics due to large model errors. Regarding the ecosystem state variables, the assimilation of satellite-derived chlorophyll concentration leads to significant reduction of the RMS errors in the observed variables during the first year, i.e. 2008, compared to a free run simulation. However, local filter divergences of the parameter component occur in 2009 and result in an increase in the RMS error at the time of the spring bloom.

Risk management for operations of the Los Alamos critical experiments facility

International Nuclear Information System (INIS)

Paternoster, R.; Butterfield, K.

1998-01-01

The Los Alamos Critical Experiments Facility (LACEF) currently operates two burst reactors (Godiva-IV and Skua), one solution assembly (SHEBA 2--Solution high-Energy Burst Assembly), two fast-spectrum benchmark assemblies (Flattop and Big Ten), and five general-purpose remote assembly machines which may be configured with nuclear materials and assembled by remote control. SNM storage vaults support these and other operations at the site. With this diverse set of operations, several approaches are possible in the analysis and management of risk. The most conservative approach would be to write a safety analysis report (SAR) for each assembly and experiment. A more cost-effective approach is to analyze the probability and consequences of several classes of operations representative of operations on each critical assembly machine and envelope the bounding case accidents. Although the neutron physics of these machines varies widely, the operations performed at LACEF fall into four operational modes: steady-state mode, approach-to-critical mode, prompt burst mode, and nuclear material operations which can include critical assembly fuel loading. The operational sequences of each mode are very nearly the same, whether operated on one assembly machine or another. The use of an envelope approach to accident analysis is facilitated by the use of classes of operations and the use of bounding case consequence analysis. A simple fault tree analysis of operational modes helps resolve which operations are sensitive to human error and which are initiated by hardware of software failures. Where possible, these errors and failures are blocked by TSR LCOs

Parameterized and resolved Southern Ocean eddy compensation

Science.gov (United States)

Poulsen, Mads B.; Jochum, Markus; Nuterman, Roman

2018-04-01

The ability to parameterize Southern Ocean eddy effects in a forced coarse resolution ocean general circulation model is assessed. The transient model response to a suite of different Southern Ocean wind stress forcing perturbations is presented and compared to identical experiments performed with the same model in 0.1° eddy-resolving resolution. With forcing of present-day wind stress magnitude and a thickness diffusivity formulated in terms of the local stratification, it is shown that the Southern Ocean residual meridional overturning circulation in the two models is different in structure and magnitude. It is found that the difference in the upper overturning cell is primarily explained by an overly strong subsurface flow in the parameterized eddy-induced circulation while the difference in the lower cell is mainly ascribed to the mean-flow overturning. With a zonally constant decrease of the zonal wind stress by 50% we show that the absolute decrease in the overturning circulation is insensitive to model resolution, and that the meridional isopycnal slope is relaxed in both models. The agreement between the models is not reproduced by a 50% wind stress increase, where the high resolution overturning decreases by 20%, but increases by 100% in the coarse resolution model. It is demonstrated that this difference is explained by changes in surface buoyancy forcing due to a reduced Antarctic sea ice cover, which strongly modulate the overturning response and ocean stratification. We conclude that the parameterized eddies are able to mimic the transient response to altered wind stress in the high resolution model, but partly misrepresent the unperturbed Southern Ocean meridional overturning circulation and associated heat transports.

Preparing to Predict: The Second Autonomous Ocean Sampling Network (AOSN-II) Experiment in the Monterey Bay

Science.gov (United States)

2008-06-06

MBARI buoy M2, profiling to 250 m depth (Figure 1). Instruments on board included a CTD, fluorometer, oxygen and nitrate sensors, bioluminescence, and...dimensional multiscale ocean variability: Massachusetts Bay. Journal of Marine Systems, Special issue on “Three-dimensional ocean circulation: Lagrangian...Oceanography”, T. Paluszkiewicz and S. Harper, Eds., Vol. 19, 1, 172-183. Liang, X.S. and Anderson, D.G.M. (2007) Multiscale Window Transform, SIAM J

Practical global oceanic state estimation

Science.gov (United States)

Wunsch, Carl; Heimbach, Patrick

2007-06-01

The problem of oceanographic state estimation, by means of an ocean general circulation model (GCM) and a multitude of observations, is described and contrasted with the meteorological process of data assimilation. In practice, all such methods reduce, on the computer, to forms of least-squares. The global oceanographic problem is at the present time focussed primarily on smoothing, rather than forecasting, and the data types are unlike meteorological ones. As formulated in the consortium Estimating the Circulation and Climate of the Ocean (ECCO), an automatic differentiation tool is used to calculate the so-called adjoint code of the GCM, and the method of Lagrange multipliers used to render the problem one of unconstrained least-squares minimization. Major problems today lie less with the numerical algorithms (least-squares problems can be solved by many means) than with the issues of data and model error. Results of ongoing calculations covering the period of the World Ocean Circulation Experiment, and including among other data, satellite altimetry from TOPEX/POSEIDON, Jason-1, ERS- 1/2, ENVISAT, and GFO, a global array of profiling floats from the Argo program, and satellite gravity data from the GRACE mission, suggest that the solutions are now useful for scientific purposes. Both methodology and applications are developing in a number of different directions.

Temperature profile data collected using BT and XBT from the CHAIN from the Atlantic Ocean during the International Decade of Ocean Exploration / Mid-Ocean Dynamics Experiment (IDOE/MODE) project, 1973-06-06 to 1973-06-13 (NODC Accession 7400724)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using BT and XBT casts from CHAIN in the Atlantic Ocean from June 6, 1973 to June 13, 1973. Data were submitted by Harvard...

Temperature profile data collected using CTD casts from the CHAIN from the Atlantic Ocean during the International Decade of Ocean Exploration / Mid-Ocean Dynamics Experiment (IDOE/MODE) project from 01 April 1973 to 30 June 1973 (NODC Accession 7400161)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using CTD casts from the CHAIN in the Atlantic Ocean from April 1, 1973 to June 30, 1973. Data were submitted by Woods Hole...

MONITORING HIGH-FREQUENCY OCEAN SIGNALS USING LOW-COST GNSS/IMU BUOYS

Directory of Open Access Journals (Sweden)

Y.-L. Huang

2016-06-01

Full Text Available In oceans there are different ocean signals covering the multi-frequencies including tsunami, meteotsunami, storm surge, as sea level change, and currents. These signals have the direct and significant impact on the economy and life of human-beings. Therefore, measuring ocean signals accurately becomes more and more important and necessary. Nowadays, there are many techniques and methods commonly used for monitoring oceans, but each has its limitation. For example, tide gauges only measure sea level relative to benchmarks and are disturbed unevenly, and satellite altimeter measurements are not continuous and inaccurate near coastal oceans. In addition, high-frequency ocean signals such as tsunami and meteotsunami cannot be sufficiently detected by 6-minutes tide gauge measurements or 10-day sampled altimetry data. Moreover, traditional accelerometer buoy is heavy, expensive and the low-frequency noise caused by the instrument is unavoidable. In this study, a small, low-cost and self-assembly autonomous Inertial Measurement Unit (IMU that independently collects continuous acceleration and angular velocity data is mounted on a GNSS buoy to provide the positions and tilts of the moving buoy. The main idea is to integrate the Differential GNSS (DGNSS or Precise Point Positioning (PPP solutions with IMU data, and then evaluate the performance by comparing with in situ tide gauges. The validation experiments conducted in the NCKU Tainan Hydraulics Laboratory showed that GNSS and IMU both can detect the simulated regular wave frequency and height, and the field experiments in the Anping Harbor, Tainan, Taiwan showed that the low-cost GNSS buoy has an excellent ability to observe significant wave heights in amplitude and frequency.

Ocean carbon sequestration by fertilization: An integrated bioeochemical assessment

Energy Technology Data Exchange (ETDEWEB)

Gruber, N.; Sarmiento, J.L.; Gnandesikan, A.

2005-05-31

Under this grant, the authors investigated a range of issues associated with the proposal to fertilize the ocean with nutrients (such as iron) in order to increase the export of organic matter from the ocean's near surface waters and consequently increase the uptake of CO{sub 2} from the atmosphere. There are several critical scientific questions that have the potential to be make-or-break issues for this proposed carbon sequestration mechanism: (1) If iron is added to the ocean, will export of organic carbon from the surface actually occur? Clearly, if no export occurs, then there will be no sequestration. (2) if iron fertilization does lead to export of organic carbon from the surface of the ocean, how much CO{sub 2} will actually be removed from the atmosphere? Even if carbon is removed from the surface of the ocean, this does not guarantee that there will be significant removal of CO{sub 2} from the atmosphere, since the CO{sub 2} may be supplied by a realignment of dissolved inorganic carbon within the ocean. (3) What is the time scale of any sequestration that occurs? If sequestered CO{sub 2} returns to the atmosphere on a relatively short time scale, iron fertilization will not contribute significantly to slowing the growth of atmospheric CO{sub 2}. (4) Can the magnitude of sequestration be verified? If verification is extremely difficult or impossible, this option is likely to be viewed less favorably. (5) What unintended consequences might there be from fertilizing the ocean with iron? If these are severe enough, they will be a significant impact on policy decisions. Most research on carbon sequestration by fertilization has focused on the first of these issues. Although a number of in situ fertilization experiments have successfully demonstrated that the addition of iron leads to a dramatic increase in ocean productivity, the question of whether this results in enhanced export remains an open one. The primary focus of the research was on the

Impacts of ocean acidification on sediment processes in shallow waters of the Arctic Ocean.

Science.gov (United States)

Gazeau, Frédéric; van Rijswijk, Pieter; Pozzato, Lara; Middelburg, Jack J

2014-01-01

Despite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO2 and usually have a lower buffering capacity than warmer waters, acidification rates in these areas are faster than those in sub-tropical regions. The present study investigates the effects of ocean acidification on sediment composition, processes and sediment-water fluxes in an Arctic coastal system. Undisturbed sediment cores, exempt of large dwelling organisms, were collected, incubated for a period of 14 days, and subject to a gradient of pCO2 covering the range of values projected for the end of the century. On five occasions during the experimental period, the sediment cores were isolated for flux measurements (oxygen, alkalinity, dissolved inorganic carbon, ammonium, nitrate, nitrite, phosphate and silicate). At the end of the experimental period, denitrification rates were measured and sediment samples were taken at several depth intervals for solid-phase analyses. Most of the parameters and processes (i.e. mineralization, denitrification) investigated showed no relationship with the overlying seawater pH, suggesting that ocean acidification will have limited impacts on the microbial activity and associated sediment-water fluxes on Arctic shelves, in the absence of active bio-irrigating organisms. Only following a pH decrease of 1 pH unit, not foreseen in the coming 300 years, significant enhancements of calcium carbonate dissolution and anammox rates were observed. Longer-term experiments on different sediment types are still required to confirm the limited impact of ocean acidification on shallow Arctic sediment processes as observed in this study.

Ocean acidification genetics - Genetics and genomics of response to ocean acidification

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — We are applying a variety of genetic tools to assess the response of our ocean resources to ocean acidification, including gene expression techniques, identification...

Ocean acidification in the Mediterranean Sea: pelagic mesocosm experiments. A synthesis

OpenAIRE

Maugendre , L.; Guieu , C.; Gattuso , J.-P.; Gazeau , F.

2017-01-01

International audience; Planet Earth has entered a new geological era, the Anthropocene, in which geologically significant conditions and processes are profoundly altered by human activities (Waters et al., 2016). Among many impacts, human activities have released excessive amounts of carbon dioxide (CO2) in the atmosphere leading to warming and ocean acidification: a decrease in pH and CO32- concentration and an increase in CO2 and HCO3- concentrations (Gattuso and Hansson, 2011). On average...

Temperature profile data collected using BT and XBT from the HUNT from the Atlantic Ocean during the International Decade of Ocean Exploration / Mid-Ocean Dynamics Experiment (IDOE/MODE) project, 1973-05-25 to 1973-06-01 (NODC Accession 7400623)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and other data were collected using BT and XBT casts from HUNT in the Atlantic Ocean from May 25, 1973 to June 1, 1973. Data were submitted by US...

Ocean acidification does not affect the physiology of the tropical coral Acropora digitifera during a 5-week experiment

Science.gov (United States)

Takahashi, A.; Kurihara, H.

2013-03-01

The increase in atmospheric CO2 concentration, which has resulted from the burning of fossil fuels, is being absorbed by the oceans and is causing ocean acidification. Ocean acidification involves the decrease of both the pH and the calcium carbonate saturation state. Ocean acidification is predicted to impact the physiology of marine organisms and reduce the calcification rates of corals. In the present study, we measured the rates of calcification, respiration, photosynthesis, and zooxanthellae density of the tropical coral Acropora digitifera under near-natural summertime temperature and sunlight for a 5-week period. We found that these key physiological parameters were not affected by both mid-CO2 (pCO2 = 744 ± 38, pH = 7.97 ± 0.02, Ωarag = 2.6 ± 0.1) and high-CO2 conditions (pCO2 = 2,142 ± 205, pH = 7.56 ± 0.04, Ωarag = 1.1 ± 0.2) throughout the 35 days experimental period. Additionally, there was no significant correlation between calcification rate and seawater aragonite saturation (Ωarag). These results suggest that the impacts of ocean acidification on corals physiology may be more complex than have been previously proposed.

Sensitivity experiments with an adaptation model of circulation of western tropical Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Bahulayan, N.; Shaji, C.; Rao, A.D.; Dube, S.K.

circulation at 10 m depth is controlled by both wind stress and sea surface topography. Circulation at 50 m depth is mainly controlled by thermohaline forcing and sea surface topography. The current speed in the western tropical Indian Ocean is of the order...

78 FR 32556 - Safety Zone; 2013 Ocean City Air Show, Atlantic Ocean; Ocean City, MD

Science.gov (United States)

2013-05-31

... FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information The... Atlantic Ocean in Ocean City, MD. In recent years, there have been unfortunate instances of jets and planes...

Comparison of the ocean surface vector winds from atmospheric reanalysis and scatterometer-based wind products over the Nordic Seas and the northern North Atlantic and their application for ocean modeling

Science.gov (United States)

Dukhovskoy, Dmitry S.; Bourassa, Mark A.; Petersen, Gudrún Nína; Steffen, John

2017-03-01

Ocean surface vector wind fields from reanalysis data sets and scatterometer-derived gridded products are analyzed over the Nordic Seas and the northern North Atlantic for the time period from 2000 to 2009. The data sets include the National Center for Environmental Prediction Reanalysis 2 (NCEPR2), Climate Forecast System Reanalysis (CFSR), Arctic System Reanalysis (ASR), Cross-Calibrated Multiplatform (CCMP) wind product version 1.1 and recently released version 2.0, and QuikSCAT. The goal of the study is to assess discrepancies across the wind vector fields in the data sets and demonstrate possible implications of these differences for ocean modeling. Large-scale and mesoscale characteristics of winds are compared at interannual, seasonal, and synoptic timescales. A cyclone tracking methodology is developed and applied to the wind fields to compare cyclone characteristics in the data sets. Additionally, the winds are evaluated against observations collected from meteorological buoys deployed in the Iceland and Irminger Seas. The agreement among the wind fields is better for longer time and larger spatial scales. The discrepancies are clearly apparent for synoptic timescales and mesoscales. CCMP, ASR, and CFSR show the closest overall agreement with each other. Substantial biases are found in the NCEPR2 winds. Numerical sensitivity experiments are conducted with a coupled ice-ocean model forced by different wind fields. The experiments demonstrate differences in the net surface heat fluxes during storms. In the experiment forced by NCEPR2 winds, there are discrepancies in the large-scale wind-driven ocean dynamics compared to the other experiments.

Temperature profile and other data collected using current meter from the CHAIN from the Atlantic Ocean in part of the International Decade of Ocean Exploration / Mid-Ocean Dynamics Experiment from 12 February 1969 to 16 March 1972 (NODC Accession 7601355)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile, current meter, and wind speed/direction data were collected using current meter from the TRIDENT, KNORR, and BILLIE 2 in the Atlantic Ocean from...

Stochastic Ocean Predictions with Dynamically-Orthogonal Primitive Equations

Science.gov (United States)

Subramani, D. N.; Haley, P., Jr.; Lermusiaux, P. F. J.

2017-12-01

The coastal ocean is a prime example of multiscale nonlinear fluid dynamics. Ocean fields in such regions are complex and intermittent with unstationary heterogeneous statistics. Due to the limited measurements, there are multiple sources of uncertainties, including the initial conditions, boundary conditions, forcing, parameters, and even the model parameterizations and equations themselves. For efficient and rigorous quantification and prediction of these uncertainities, the stochastic Dynamically Orthogonal (DO) PDEs for a primitive equation ocean modeling system with a nonlinear free-surface are derived and numerical schemes for their space-time integration are obtained. Detailed numerical studies with idealized-to-realistic regional ocean dynamics are completed. These include consistency checks for the numerical schemes and comparisons with ensemble realizations. As an illustrative example, we simulate the 4-d multiscale uncertainty in the Middle Atlantic/New York Bight region during the months of Jan to Mar 2017. To provide intitial conditions for the uncertainty subspace, uncertainties in the region were objectively analyzed using historical data. The DO primitive equations were subsequently integrated in space and time. The probability distribution function (pdf) of the ocean fields is compared to in-situ, remote sensing, and opportunity data collected during the coincident POSYDON experiment. Results show that our probabilistic predictions had skill and are 3- to 4- orders of magnitude faster than classic ensemble schemes.

Rain-shadow: An area harboring "Gray Ocean" clouds

Science.gov (United States)

Padmakumari, B.; Maheskumar, R. S.; Harikishan, G.; Morwal, S. B.; Kulkarni, J. R.

2018-06-01

The characteristics of monsoon convective clouds over the rain-shadow region of north peninsular India have been investigated using in situ aircraft cloud microphysical observations collected during Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX). The parameters considered for characterization are: liquid water content (LWC), cloud vertical motion (updraft, downdraft: w), cloud droplet number concentration (CDNC) and effective radius (Re). The results are based on 15 research flights which were conducted from the base station Hyderabad during summer monsoon season. The clouds studied were developing congestus. The clouds have low CDNC and low updraft values resembling the oceanic convective clouds. The super-saturation in clouds is found to be low (≤0.2%) due to low updrafts. The land surface behaves like ocean surface during monsoon as deduced from Bowen ratio. Microphysically the clouds showed oceanic characteristics. However, these clouds yield low rainfall due to their low efficiency (mean 14%). The cloud parameters showed a large variability; hence their characteristic values are reported in terms of median values. These values will serve the numerical models for rainfall simulations over the region and also will be useful as a scientific basis for cloud seeding operations to increase the rainfall efficiency. The study revealed that monsoon convective clouds over the rain-shadow region are of oceanic type over the gray land, and therefore we christen them as "Gray Ocean" clouds.

Breaking Waves on the Ocean Surface

Science.gov (United States)

Schwendeman, Michael S.

In the open ocean, breaking waves are a critical mechanism for the transfer of energy, momentum, and mass between the atmosphere and the ocean. Despite much study, fundamental questions about wave breaking, such as what determines whether a wave will break, remain unresolved. Measurements of oceanic breakers, or "whitecaps," are often used to validate the hypotheses derived in simplified theoretical, numerical, or experimental studies. Real-world measurements are also used to improve the parameterizations of wave-breaking in large global models, such as those forecasting climate change. Here, measurements of whitecaps are presented using ship-based cameras, from two experiments in the North Pacific Ocean. First, a method for georectifying the camera imagery is described using the distant horizon, without additional instrumentation. Over the course of the experiment, this algorithm correctly identifies the horizon in 92% of images in which it is visible. In such cases, the calculation of camera pitch and roll is accurate to within 1 degree. The main sources of error in the final georectification are from mislabeled horizons due to clouds, rain, or poor lighting, and from vertical "heave" motions of the camera, which cannot be calculated with the horizon method. This method is used for correcting the imagery from the first experiment, and synchronizing the imagery from the second experiment to an onboard inertial motion package. Next, measurements of the whitecap coverage, W, are shown from both experiments. Although W is often used in models to represent whitecapping, large uncertainty remains in the existing parameterizations. The data show good agreement with recent measurements using the wind speed. Although wave steepness and dissipation are hypothesized to be more robust predictors of W, this is shown to not always be the case. Wave steepness shows comparable success to the wind parameterizations only when using a mean-square slope variable calculated over the

The influence of UV irradiation on the photoreduction of iron in the Southern Ocean

NARCIS (Netherlands)

Rijkenberg, M J A; Fischer, AC; Kroon, JJ; Gerringa, LJA; Timmermans, KR; Wolterbeek, HT; de Baar, H J W

2005-01-01

An iron enrichment experiment, EisenEx, was performed in the Atlantic sector of the Southern Ocean during the Antarctic spring of 2000. Deck incubations of open ocean water were performed to investigate the influence of ultraviolet B (UVB: 280-315 nm) and ultraviolet A (UVA: 315-400 nm) on the

Temperature profile data from STD/CTD casts from the KNORR and other platforms from the Atlantic Ocean during the International Decade Of Ocean Exploration / Mid-Ocean Dynamics Experiment (IDOE/MODE) project, 23 March 1972 to 20 December 1976 (NODC Accession 7617996)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data were collected using SDT/CDT casts from KNORR and other platforms in the Atlantic Ocean from March 23, 1972 to December 20,...

Sensitivity of decadal predictions to the initial atmospheric and oceanic perturbations

Energy Technology Data Exchange (ETDEWEB)

Du, H.; Garcia-Serrano, J.; Guemas, V.; Soufflet, Y. [Institut Catala de Ciencies del Clima (IC3), Barcelona (Spain); Doblas-Reyes, F.J. [Institut Catala de Ciencies del Clima (IC3), Barcelona (Spain); Institucio Catalana de Recerca i Estudis Avancats (ICREA), Barcelona (Spain); Wouters, B. [Royal Netherlands Meteorological Institute (KNMI), De Bilt (Netherlands)

2012-10-15

A coupled global atmosphere-ocean model is employed to investigate the impact of initial perturbation methods on the behaviour of five-member ensemble decadal re-forecasts. Three initial-condition perturbation strategies, atmosphere only, ocean only and atmosphere-ocean, have been used and the impact on selected variables have been investigated. The impact has been assessed in terms of climate drift, forecast quality and spread. The simulated global means of near-surface air temperature (T2M), sea surface temperature (SST) and sea ice area (SIA) for both Arctic and Antarctic show reasonably good quality, in spite of the non-negligible drift of the model. The skill in terms of correlation is not significantly affected by the particular perturbation method employed. The ensemble spread generated for T2M, SST and land surface precipitation (PCP) saturates quickly with any of the perturbation methods. However, for SIA, Atlantic meridional overturning circulation (AMOC) and ocean heat content (OHC), the spread increases substantially during the forecast time when ocean perturbations are applied. Ocean perturbations are particularly important for Antarctic SIA and OHC for the middle and deep layers of the ocean. The results will be helpful in the design of ensemble prediction experiments. (orig.)

Proceedings of oceans '91

International Nuclear Information System (INIS)

Anon.

1991-01-01

This volume contains the proceedings of the Oceans '91 Conference. Topics addressed include: ocean energy conversion, marine communications and navigation, ocean wave energy conversion, environmental modeling, global climate change, ocean minerals technology, oil spill technology, and submersible vehicles

An inventory of Arctic Ocean data in the World Ocean Database

Science.gov (United States)

Zweng, Melissa M.; Boyer, Tim P.; Baranova, Olga K.; Reagan, James R.; Seidov, Dan; Smolyar, Igor V.

2018-03-01

The World Ocean Database (WOD) contains over 1.3 million oceanographic casts (where cast refers to an oceanographic profile or set of profiles collected concurrently at more than one depth between the ocean surface and ocean bottom) collected in the Arctic Ocean basin and its surrounding marginal seas. The data, collected from 1849 to the present, come from many submitters and countries, and were collected using a variety of instruments and platforms. These data, along with the derived products World Ocean Atlas (WOA) and the Arctic Regional Climatologies, are exceptionally useful - the data are presented in a standardized, easy to use format and include metadata and quality control information. Collecting data in the Arctic Ocean is challenging, and coverage in space and time ranges from excellent to nearly non-existent. WOD continues to compile a comprehensive collection of Arctic Ocean profile data, ideal for oceanographic, environmental and climatic analyses (https://doi.org/10.7289/V54Q7S16" target="_blank">https://doi.org/10.7289/V54Q7S16).

Ocean Hydrodynamics Numerical Model in Curvilinear Coordinates for Simulating Circulation of the Global Ocean and its Separate Basins.

Science.gov (United States)

Gusev, Anatoly; Diansky, Nikolay; Zalesny, Vladimir

2010-05-01

The original program complex is proposed for the ocean circulation sigma-model, developed in the Institute of Numerical Mathematics (INM), Russian Academy of Sciences (RAS). The complex can be used in various curvilinear orthogonal coordinate systems. In addition to ocean circulation model, the complex contains a sea ice dynamics and thermodynamics model, as well as the original system of the atmospheric forcing implementation on the basis of both prescribed meteodata and atmospheric model results. This complex can be used as the oceanic block of Earth climate model as well as for solving the scientific and practical problems concerning the World ocean and its separate oceans and seas. The developed program complex can be effectively used on parallel shared memory computational systems and on contemporary personal computers. On the base of the complex proposed the ocean general circulation model (OGCM) was developed. The model is realized in the curvilinear orthogonal coordinate system obtained by the conformal transformation of the standard geographical grid that allowed us to locate the system singularities outside the integration domain. The horizontal resolution of the OGCM is 1 degree on longitude, 0.5 degree on latitude, and it has 40 non-uniform sigma-levels in depth. The model was integrated for 100 years starting from the Levitus January climatology using the realistic atmospheric annual cycle calculated on the base of CORE datasets. The experimental results showed us that the model adequately reproduces the basic characteristics of large-scale World Ocean dynamics, that is in good agreement with both observational data and results of the best climatic OGCMs. This OGCM is used as the oceanic component of the new version of climatic system model (CSM) developed in INM RAS. The latter is now ready for carrying out the new numerical experiments on climate and its change modelling according to IPCC (Intergovernmental Panel on Climate Change) scenarios in the

Oceans Melting Greenland: Early Results from NASA's Ocean-Ice Mission in Greenland

DEFF Research Database (Denmark)

Fenty, Ian; Willis, Josh K.; Khazendar, Ala

2016-01-01

the continental shelf, and about the extent to which the ocean interacts with glaciers. Early results from NASA's five-year Oceans Melting Greenland (OMG) mission, based on extensive hydrographic and bathymetric surveys, suggest that many glaciers terminate in deep water and are hence vulnerable to increased...... melting due to ocean-ice interaction. OMG will track ocean conditions and ice loss at glaciers around Greenland through the year 2020, providing critical information about ocean-driven Greenland ice mass loss in a warming climate....

Reversal of ocean acidification enhances net coral reef calcification.

Science.gov (United States)

Albright, Rebecca; Caldeira, Lilian; Hosfelt, Jessica; Kwiatkowski, Lester; Maclaren, Jana K; Mason, Benjamin M; Nebuchina, Yana; Ninokawa, Aaron; Pongratz, Julia; Ricke, Katharine L; Rivlin, Tanya; Schneider, Kenneth; Sesboüé, Marine; Shamberger, Kathryn; Silverman, Jacob; Wolfe, Kennedy; Zhu, Kai; Caldeira, Ken

2016-03-17

Approximately one-quarter of the anthropogenic carbon dioxide released into the atmosphere each year is absorbed by the global oceans, causing measurable declines in surface ocean pH, carbonate ion concentration ([CO3(2-)]), and saturation state of carbonate minerals (Ω). This process, referred to as ocean acidification, represents a major threat to marine ecosystems, in particular marine calcifiers such as oysters, crabs, and corals. Laboratory and field studies have shown that calcification rates of many organisms decrease with declining pH, [CO3(2-)], and Ω. Coral reefs are widely regarded as one of the most vulnerable marine ecosystems to ocean acidification, in part because the very architecture of the ecosystem is reliant on carbonate-secreting organisms. Acidification-induced reductions in calcification are projected to shift coral reefs from a state of net accretion to one of net dissolution this century. While retrospective studies show large-scale declines in coral, and community, calcification over recent decades, determining the contribution of ocean acidification to these changes is difficult, if not impossible, owing to the confounding effects of other environmental factors such as temperature. Here we quantify the net calcification response of a coral reef flat to alkalinity enrichment, and show that, when ocean chemistry is restored closer to pre-industrial conditions, net community calcification increases. In providing results from the first seawater chemistry manipulation experiment of a natural coral reef community, we provide evidence that net community calcification is depressed compared with values expected for pre-industrial conditions, indicating that ocean acidification may already be impairing coral reef growth.

Ocean acidification challenges copepod phenotypic plasticity

Directory of Open Access Journals (Sweden)

A. Vehmaa

2016-11-01

Full Text Available Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC as a function of acidification (fCO2  ∼  365–1231 µatm and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm or quality (C : N weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

Ocean acidification challenges copepod reproductive plasticity

Science.gov (United States)

Vehmaa, A.; Almén, A.-K.; Brutemark, A.; Paul, A.; Riebesell, U.; Furuhagen, S.; Engström-Öst, J.

2015-11-01

Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia bifilosa in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ~ 365-1231 μatm), and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal if transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female copepod size and egg hatching success. In addition, we found a threshold of fCO2 concentration (~ 1000 μatm), above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon ~ 55 μm) or quality (C : N) weakens the transgenerational effects. However, females with high ORAC produced eggs with high hatching success. Overall, these results indicate that A. bifilosa could be affected by projected near future CO2 levels.

Regional impacts of ocean color on tropical Pacific variability

Science.gov (United States)

Anderson, W.; Gnanadesikan, A.; Wittenberg, A.

2009-08-01

The role of the penetration length scale of shortwave radiation into the surface ocean and its impact on tropical Pacific variability is investigated with a fully coupled ocean, atmosphere, land and ice model. Previous work has shown that removal of all ocean color results in a system that tends strongly towards an El Niño state. Results from a suite of surface chlorophyll perturbation experiments show that the mean state and variability of the tropical Pacific is highly sensitive to the concentration and distribution of ocean chlorophyll. Setting the near-oligotrophic regions to contain optically pure water warms the mean state and suppresses variability in the western tropical Pacific. Doing the same above the shadow zones of the tropical Pacific also warms the mean state but enhances the variability. It is shown that increasing penetration can both deepen the pycnocline (which tends to damp El Niño) while shifting the mean circulation so that the wind response to temperature changes is altered. Depending on what region is involved this change in the wind stress can either strengthen or weaken ENSO variability.

An Optimization Method for Virtual Globe Ocean Surface Dynamic Visualization

Directory of Open Access Journals (Sweden)

HUANG Wumeng

2016-12-01

Full Text Available The existing visualization method in the virtual globe mainly uses the projection grid to organize the ocean grid. This special grid organization has the defects in reflecting the difference characteristics of different ocean areas. The method of global ocean visualization based on global discrete grid can make up the defect of the projection grid method by matching with the discrete space of the virtual globe, so it is more suitable for the virtual ocean surface simulation application.But the available global discrete grids method has many problems which limiting its application such as the low efficiency of rendering and loading, the need of repairing grid crevices. To this point, we propose an optimization for the global discrete grids method. At first, a GPU-oriented multi-scale grid model of ocean surface which develops on the foundation of global discrete grids was designed to organize and manage the ocean surface grids. Then, in order to achieve the wind-drive wave dynamic rendering, this paper proposes a dynamic wave rendering method based on the multi-scale ocean surface grid model to support real-time wind field updating. At the same time, considering the effect of repairing grid crevices on the system efficiency, this paper presents an efficient method for repairing ocean surface grid crevices based on the characteristics of ocean grid and GPU technology. At last, the feasibility and validity of the method are verified by the comparison experiment. The experimental results show that the proposed method is efficient, stable and fast, and can compensate for the lack of function of the existing methods, so the application range is more extensive.

GFDL CM2.1 Global Coupled Ocean-Atmosphere Model Water ...

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. GFDL CM2.1 Global Coupled Ocean-Atmosphere Model Water Hosing Experiment with 1 Sv equivalent of Freshening Control Expt: 100 yrs After Hosing: 300 yrs.

Pliocene palaeoceanography of the Arctic Ocean and subarctic seas.

Science.gov (United States)

Matthiessen, Jens; Knies, Jochen; Vogt, Christoph; Stein, Ruediger

2009-01-13

The Pliocene is important in the geological evolution of the high northern latitudes. It marks the transition from restricted local- to extensive regional-scale glaciations on the circum-Arctic continents between 3.6 and 2.4Ma. Since the Arctic Ocean is an almost land-locked basin, tectonic activity and sea-level fluctuations controlled the geometry of ocean gateways and continental drainage systems, and exerted a major influence on the formation of continental ice sheets, the distribution of river run-off, and the circulation and water mass characteristics in the Arctic Ocean. The effect of a water mass exchange restricted to the Bering and Fram Straits on the oceanography is unknown, but modelling experiments suggest that this must have influenced the Atlantic meridional overturning circulation. Cold conditions associated with perennial sea-ice cover might have prevailed in the central Arctic Ocean throughout the Pliocene, whereas colder periods alternated with warmer seasonally ice-free periods in the marginal areas. The most pronounced oceanographic change occurred in the Mid-Pliocene when the circulation through the Bering Strait reversed and low-salinity waters increasingly flowed from the North Pacific into the Arctic Ocean. The excess freshwater supply might have facilitated sea-ice formation and contributed to a decrease in the Atlantic overturning circulation.

An Oceanic General Circulation Model (OGCM) investigation of the Red Sea circulation, 1. Exchange between the Red Sea and the Indian Ocean

Science.gov (United States)

Sofianos, Sarantis S.; Johns, William E.

2002-11-01

The mechanisms involved in the seasonal exchange between the Red Sea and the Indian Ocean are studied using an Oceanic General Circulation Model (OGCM), namely the Miami Isopycnic Coordinate Ocean Model (MICOM). The model reproduces the basic characteristics of the seasonal circulation observed in the area of the strait of Bab el Mandeb. There is good agreement between model results and available observations on the strength of the exchange and the characteristics of the water masses involved, as well as the seasonal flow pattern. During winter, this flow consists of a typical inverse estuarine circulation, while during summer, the surface flow reverses, there is an intermediate inflow of relatively cold and fresh water, and the hypersaline outflow at the bottom of the strait is significantly reduced. Additional experiments with different atmospheric forcing (seasonal winds, seasonal thermohaline air-sea fluxes, or combinations) were performed in order to assess the role of the atmospheric forcing fields in the exchange flow at Bab el Mandeb. The results of both the wind- and thermohaline-driven experiments exhibit a strong seasonality at the area of the strait, which is in phase with the observations. However, it is the combination of both the seasonal pattern of the wind stress and the seasonal thermohaline forcing that can reproduce the observed seasonal variability at the strait. The importance of the seasonal cycle of the thermohaline forcing on the exchange flow pattern is also emphasized by these results. In the experiment where the thermohaline forcing is represented by its annual mean, the strength of the exchange is reduced almost by half.

Exploiting Thread Parallelism for Ocean Modeling on Cray XC Supercomputers

Energy Technology Data Exchange (ETDEWEB)

Sarje, Abhinav [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jacobsen, Douglas W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Williams, Samuel W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ringler, Todd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Oliker, Leonid [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-05-01

The incorporation of increasing core counts in modern processors used to build state-of-the-art supercomputers is driving application development towards exploitation of thread parallelism, in addition to distributed memory parallelism, with the goal of delivering efficient high-performance codes. In this work we describe the exploitation of threading and our experiences with it with respect to a real-world ocean modeling application code, MPAS-Ocean. We present detailed performance analysis and comparisons of various approaches and configurations for threading on the Cray XC series supercomputers.

Oceanic archipelagos

DEFF Research Database (Denmark)

Triantis, Kostas A.; Whittaker, Robert James; Fernández-Palacios, José María

2016-01-01

Since the contributions of Charles Darwin and Alfred Russel Wallace, oceanic archipelagos have played a central role in the development of biogeography. However, despite the critical influence of oceanic islands on ecological and evolutionary theory, our focus has remained limited to either the i...... of the archipelagic geological dynamics that can affect diversity at both the island and the archipelagic level. We also reaffirm that oceanic archipelagos are appropriate spatiotemporal units to frame analyses in order to understand large scale patterns of biodiversity....

Our Storied Sea: Crafting a Collective Narrative of the Ocean through Accompaniment

Science.gov (United States)

Savoie, Gianna M.

Never before have we had such broad access to scientific information about the sea, yet as the world's oceans slip into a state of crisis, the American public's grasp of the issues is far from firm. But how do we begin to understand something as vast as the ocean, an area that covers more than two-thirds of our planet, when less than ten-percent of it has been explored? The ocean we "know" represents many things to many people; for some, it is a realm to be feared, for others, it is a resource to be exploited, and yet for others, it is a home to protect. This dissertation tracks an ever-evolving narrative of the ocean and examines how we come to infuse it with meaning. I contend that many Westerners relate to this space that we call the sea as a place not through a personal history, but via a translated history by those who have conveyed that experience to the public through visual storytelling. As we have been primarily on the receiving end of narratives "owned" and dictated by select voices, I argue there has remained a disconnect with the sea that has troubled our relationship with it. In today's rapidly expanding media landscape, we now have the opportunity to participate in the ocean's story as never before. I propose we disrupt the notion of "narrative ownership" as it may serve to limit understanding, and turn instead to a shared narrative that embraces diverse perspectives in order to broaden our depth of knowledge and our relationship with the sea. Further, this work examines the ways in which the shifting digital and social media terrain is enabling ocean scientists to blur the lines between science and advocacy in order to invest the public in stewardship. I argue that in order to be effective, the science narrative can no longer simply inform; it must engage the public by incorporating human agency into the story of the ocean. Only when we share a collective narrative of the ocean, will we be able to fully invest in its protection. To that end, I

Biotic and human vulnerability to projected changes in ocean biogeochemistry over the 21st century.

Science.gov (United States)

Mora, Camilo; Wei, Chih-Lin; Rollo, Audrey; Amaro, Teresa; Baco, Amy R; Billett, David; Bopp, Laurent; Chen, Qi; Collier, Mark; Danovaro, Roberto; Gooday, Andrew J; Grupe, Benjamin M; Halloran, Paul R; Ingels, Jeroen; Jones, Daniel O B; Levin, Lisa A; Nakano, Hideyuki; Norling, Karl; Ramirez-Llodra, Eva; Rex, Michael; Ruhl, Henry A; Smith, Craig R; Sweetman, Andrew K; Thurber, Andrew R; Tjiputra, Jerry F; Usseglio, Paolo; Watling, Les; Wu, Tongwen; Yasuhara, Moriaki

2013-10-01

Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world's ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world's ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions.

Biotic and human vulnerability to projected changes in ocean biogeochemistry over the 21st century.

Directory of Open Access Journals (Sweden)

Camilo Mora

2013-10-01

Full Text Available Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world's ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world's ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions.

Ocean water cycle: its recent amplification and impact on ocean circulation

Science.gov (United States)

Vinogradova, Nadya

2016-04-01

Oceans are the largest reservoir of the world's water supply, accounting for 97% of the Earth's water and supplying more than 75% of the evaporated and precipitated water in the global water cycle. Therefore, in order to predict the future of the global hydrological cycle, it is essential to understand the changes in its largest component, which is the flux of freshwater over the oceans. Here we examine the change in the ocean water cycle and the ocean's response to such changes that were happening during the last two decades. The analysis is based on a data-constrained ocean state estimate that synthesizes all of the information available in the surface fluxes, winds, observations of sea level, temperature, salinity, geoid, etc., as well as in the physical constraints, dynamics, and conservation statements that are embedded in the equations of the MIT general circulation model. Closeness to observations and dynamical consistency of the solution ensures a physically realistic correspondence between the atmospheric forcing and oceanic fluxes, including the ocean's response to freshwater input. The results show a robust pattern of change in the ocean water cycle in the last twenty years. The pattern of changes indicates a general tendency of drying of the subtropics, and wetting in the tropics and mid-to-high latitudes, following the "rich get richer and the poor get poorer" paradigm in many ocean regions. Using a closed property budget analysis, we then investigate the changes in the oceanic state (salinity, temperature, sea level) during the same twenty-year period. The results are discussed in terms of the origin of surface signatures, and differentiated between those that are attributed to short-term natural variability and those that result from an intensified hydrological cycle due to warming climate.

Pb, Nd and Sr isotopes in oceanic ferromanganese deposits and ocean floor basalts

International Nuclear Information System (INIS)

O'Nions, R.K.; Carter, S.R.; Cohen, R.S.; Evensen, N.M.; Hamilton, P.J.

1978-01-01

The Pb-, Nd-, and Sr-isotope compositions of oceanic ferromanganese deposits, together with the Nd- and Sr-isotope compositions of altered ocean-floor basalts, are here reported. These data are used to evaluate these metals as sources in both the oceans and ocean ferromanganese deposits and the extent to which ocean-floor basalts may be a source of, or a sink for, these metals. (author)

Ethane ocean on Titan

Science.gov (United States)

Lunine, J. I.; Stevenson, D. J.; Yung, Y.L.

1983-01-01

Voyager I radio occultation data is employed to develop a qualitative model of an ethane ocean on Titan. It is suggested that the ocean contains 25 percent CH4 and that the ocean is in dynamic equilibrium with an N2 atmosphere. Previous models of a CH4 ocean are discounted due to photolysis rates of CH4 gas. Tidal damping of Titan's orbital eccentricity is taken as evidence for an ocean layer approximately 1 km deep, with the ocean floor being covered with a solid C2H2 layer 100 to 200 m thick. The photolytic process disrupting the CH4, if the estimates of the oceanic content of CH4 are correct, could continue for at least one billion years. Verification of the model is dependent on detecting CH4 clouds in the lower atmosphere, finding C2H6 saturation in the lower troposphere, or obtaining evidence of a global ocean.

Risk management for operations of the LANL Critical Experiments Facility

International Nuclear Information System (INIS)

Paternoster, R.; Butterfield, K.

1998-01-01

The Los Alamos Critical Experiments Facility (LACEF) currently operates two burst reactors (Godiva-IV and Skua), one solution assembly [the Solution High-Energy Burst Assembly (SHEBA)], two fast-spectrum benchmark assemblies (Flattop and Big Ten), and five general-purpose remote assembly machines that may be configured with nuclear materials and assembled by remote control. Special nuclear materials storage vaults support these and other operations at the site. With this diverse set of operations, several approaches are possible in the analysis and management of risk. The most conservative approach would be to write a safety analysis report (SAR) for each assembly and experiment. A more cost-effective approach is to analyze the probability and consequences of several classes of operations representative of operations on each critical assembly machine and envelope the bounding case accidents. Although the neutron physics of these machines varies widely, the operations performed at LACEF fall into four operational modes: steady-state mode, approach-to-critical mode, prompt burst mode, and nuclear material operations, which can include critical assembly fuel loading. The operational sequences of each mode are very nearly identical, whether operated on one assembly machine or another. The use of an envelope approach to accident analysis is facilitated by the use of classes of operations and the use of bounding case consequence analysis. A simple fault tree analysis of operational modes helps resolve which operations are sensitive to human error and which are initiated by hardware of software failures. Where possible, these errors and failures are blocked by TSR LCOs. Future work will determine the probability of accidents with various initiators

Ocean Ambient Noise Measurement and Theory

CERN Document Server

Carey, William M

2011-01-01

This book develops the theory of ocean ambient noise mechanisms and measurements, and also describes general noise characteristics and computational methods.  It concisely summarizes the vast ambient noise literature using theory combined with key representative results.  The air-sea boundary interaction zone is described in terms of non-dimensional variables requisite for future experiments.  Noise field coherency, rare directional measurements, and unique basin scale computations and methods are presented.  The use of satellite measurements in these basin scale models is demonstrated.  Finally, this book provides a series of appendices giving in-depth mathematical treatments.  With its complete and careful discussions of both theory and experimental results, this book will be of the greatest interest to graduate students and active researchers working in fields related to ambient noise in the ocean.

Southern hemisphere ocean CO2 uptake: reconciling atmospheric and oceanic estimates

International Nuclear Information System (INIS)

Roy, T.; Matear, R.; Rayner, P.; Francey, R.

2003-01-01

Using an atmospheric inversion model we investigate the southern hemisphere ocean CO 2 uptake. From sensitivity studies that varied both the initial ocean flux distribution and the atmospheric data used in the inversion, our inversion predicted a total (ocean and land) uptake of 1.65-1.90 Gt C/yr. We assess the consistency between the mean southern hemisphere ocean uptake predicted by an atmospheric inversion model for the 1991-1997 period and the T99 ocean flux estimate based on observed pCO 2 in Takahashi et al. (2002; Deep-Sea Res II, 49, 1601-1622). The inversion can not match the large 1.8 Gt C/yr southern extratropical (20-90 deg S) uptake of the T99 ocean flux estimate without producing either unreasonable land fluxes in the southern mid-latitudes or by increasing the mismatches between observed and simulated atmospheric CO 2 data. The southern extratropical uptake is redistributed between the mid and high latitudes. Our results suggest that the T99 estimate of the Southern Ocean uptake south of 50 deg S is too large, and that the discrepancy reflects the inadequate representation of wintertime conditions in the T99 estimate

Application of deep convolutional neural networks for ocean front recognition

Science.gov (United States)

Lima, Estanislau; Sun, Xin; Yang, Yuting; Dong, Junyu

2017-10-01

Ocean fronts have been a subject of study for many years, a variety of methods and algorithms have been proposed to address the problem of ocean fronts. However, all these existing ocean front recognition methods are built upon human expertise in defining the front based on subjective thresholds of relevant physical variables. This paper proposes a deep learning approach for ocean front recognition that is able to automatically recognize the front. We first investigated four existing deep architectures, i.e., AlexNet, CaffeNet, GoogLeNet, and VGGNet, for the ocean front recognition task using remote sensing (RS) data. We then propose a deep network with fewer layers compared to existing architecture for the front recognition task. This network has a total of five learnable layers. In addition, we extended the proposed network to recognize and classify the front into strong and weak ones. We evaluated and analyzed the proposed network with two strategies of exploiting the deep model: full-training and fine-tuning. Experiments are conducted on three different RS image datasets, which have different properties. Experimental results show that our model can produce accurate recognition results.

On usage of CABARET scheme for tracer transport in INM ocean model

International Nuclear Information System (INIS)

Diansky, Nikolay; Kostrykin, Sergey; Gusev, Anatoly; Salnikov, Nikolay

2010-01-01

The contemporary state of ocean numerical modelling sets some requirements for the numerical advection schemes used in ocean general circulation models (OGCMs). The most important requirements are conservation, monotonicity and numerical efficiency including good parallelization properties. Investigation of some advection schemes shows that one of the best schemes satisfying the criteria is CABARET scheme. 3D-modification of the CABARET scheme was used to develop a new transport module (for temperature and salinity) for the Institute of Numerical Mathematics ocean model (INMOM). Testing of this module on some common benchmarks shows a high accuracy in comparison with the second-order advection scheme used in the INMOM. This new module was incorporated in the INMOM and experiments with the modified model showed a better simulation of oceanic circulation than its previous version.

Global Ocean Phytoplankton

Science.gov (United States)

Franz, B. A.; Behrenfeld, M. J.; Siegel, D. A.; Werdell, P. J.

2014-01-01

Marine phytoplankton are responsible for roughly half the net primary production (NPP) on Earth, fixing atmospheric CO2 into food that fuels global ocean ecosystems and drives the ocean's biogeochemical cycles. Phytoplankton growth is highly sensitive to variations in ocean physical properties, such as upper ocean stratification and light availability within this mixed layer. Satellite ocean color sensors, such as the Sea-viewing Wide Field-of-view Sensor (SeaWiFS; McClain 2009) and Moderate Resolution Imaging Spectroradiometer (MODIS; Esaias 1998), provide observations of sufficient frequency and geographic coverage to globally monitor physically-driven changes in phytoplankton distributions. In practice, ocean color sensors retrieve the spectral distribution of visible solar radiation reflected upward from beneath the ocean surface, which can then be related to changes in the photosynthetic phytoplankton pigment, chlorophyll- a (Chla; measured in mg m-3). Here, global Chla data for 2013 are evaluated within the context of the 16-year continuous record provided through the combined observations of SeaWiFS (1997-2010) and MODIS on Aqua (MODISA; 2002-present). Ocean color measurements from the recently launched Visible and Infrared Imaging Radiometer Suite (VIIRS; 2011-present) are also considered, but results suggest that the temporal calibration of the VIIRS sensor is not yet sufficiently stable for quantitative global change studies. All MODISA (version 2013.1), SeaWiFS (version 2010.0), and VIIRS (version 2013.1) data presented here were produced by NASA using consistent Chla algorithms.

Intraspecific variations in responses to ocean acidification in two branching coral species.

Science.gov (United States)

Sekizawa, Ayami; Uechi, Hikaru; Iguchi, Akira; Nakamura, Takashi; Kumagai, Naoki H; Suzuki, Atsushi; Sakai, Kazuhiko; Nojiri, Yukihiro

2017-09-15

Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO 2 , respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO 2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration. Copyright © 2017 Elsevier Ltd. All rights reserved.

First evaluation of MyOcean altimetric data in the Arctic Ocean

DEFF Research Database (Denmark)

Cheng, Yongcun; Andersen, Ole Baltazar; Knudsen, Per

2012-01-01

The MyOcean V2 preliminary (V2p) data set of weekly gridded sea level anomaly (SLA) maps from 1993 to 2009 over the Arctic region is evaluated against existing altimetric data sets and tide gauge data. Compared with DUACS V3.0.0 (Data Unification and Altimeter Combination System) data set, MyOcean...... V2p data set improves spatial coverage and quality as well as maximum temporal correlation coefficient between altimetry and tide gauge data. The estimated amplitude of sea level annual signal and linear sea level trend from MyOcean data set are evaluated against altimetry from DUACS and RADS (Radar...... Altimeter Database System), the SODA (Simple Ocean Data Assimilation) ocean reanalysis and tide gauge data sets from PSMSL (Permanent Service for Mean Sea Level). The results show that the MyOcean data set fits in-situ measurements better than DUACS data set with respect to amplitude of annual signal...

The Southern Ocean Observing System

OpenAIRE

Rintoul, Stephen R.; Meredith, Michael P.; Schofield, Oscar; Newman, Louise

2012-01-01

The Southern Ocean includes the only latitude band where the ocean circles the earth unobstructed by continental boundaries. This accident of geography has profound consequences for global ocean circulation, biogeochemical cycles, and climate. The Southern Ocean connects the ocean basins and links the shallow and deep limbs of the overturning circulation (Rintoul et al., 2001). The ocean's capacity to moderate the pace of climate change is therefore influenced strongly by the Southern Ocean's...

Importance of 3D Processes Near the Ocean's Surface for Material Transport

Science.gov (United States)

Ozgokmen, T. M.

2014-12-01

There are a number of practical problems that demand an accurate knowledge of ocean currents near the surface of the ocean. It is known that oceanic coherent features transport heat and carry out vertical exchange of biogeochemical tracers. Ocean currents can affect biological primary production, air-sea gas exchanges and global tracer budgets. Ocean currents are also important for the dispersion of substances that pose a danger to society, economy and human health. Examples of such events include algal blooms, the Fukushima nuclear plant incident in the Pacific Ocean in 2011, and repeated large oil spills in the Gulf of Mexico, namely the IXTOC in 1978 and the Deepwater Horizon event in 2010. Such incidents demand accurate answers to questions such as ``where will the pollutant go?", ``how fast will it get there?" and ``how much pollutant will arrive there?", and in some instances ``where did the pollutant come from?". The answers to these questions are critical to the allocation of limited response resources, and in determining the overall impact of the events. We will summarize the efforts by the Consortium for Advanced Research on Transport of Hydrocarbon in the Environment (CARTHE). One of the primary objectives of CARTHE is to improve predictive modeling capability for flows near the air-sea interface. In particular, two large experiments, Grand Lagrangian Deployment (GLAD) and Surf-zone and Coastal Oil Pathways Experiment (SCOPE), coordinated with real-time modeling were instructive on processes influencing near-surface material transport. Findings on submesoscale flows as well as model deficiencies to capture processes relevant to transport will be discussed. Insight into future modeling and observational plans will be provided.

Seasonal carbonate chemistry covariation with temperature, oxygen, and salinity in a fjord estuary: implications for the design of ocean acidification experiments.

Directory of Open Access Journals (Sweden)

Jonathan C P Reum

Full Text Available Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall. pCO2 exceeded the 2008-2011 mean atmospheric level (392 µatm at all depths and seasons sampled except for the near-surface waters (< 10 m in the summer. Further, undersaturated conditions with respect to the biogenic carbonate mineral aragonite were widespread (Ωar<1. We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31, was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight

Ship Track for The Hidden Ocean Arctic 2005 - Office of Ocean Exploration

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Ship track of the US Coast Guard icebreaker Healy during the "Hidden Ocean Arctic 2005" expedition sponsored by the National Oceanic and Atmospheric Administration...

Ocean technology

Digital Repository Service at National Institute of Oceanography (India)

Peshwe, V.B.

stream_size 2 stream_content_type text/plain stream_name Voices_Oceans_1996_113.pdf.txt stream_source_info Voices_Oceans_1996_113.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

Completing the Feedback Loop: The Impact of Chlorophyll Data Assimilation on the Ocean State

Science.gov (United States)

Borovikov, Anna; Keppenne, Christian; Kovach, Robin

2015-01-01

In anticipation of the integration of a full biochemical model into the next generation GMAO coupled system, an intermediate solution has been implemented to estimate the penetration depth (1Kd_PAR) of ocean radiation based on the chlorophyll concentration. The chlorophyll is modeled as a tracer with sources-sinks coming from the assimilation of MODIS chlorophyll data. Two experiments were conducted with the coupled ocean-atmosphere model. In the first, climatological values of Kpar were used. In the second, retrieved daily chlorophyll concentrations were assimilated and Kd_PAR was derived according to Morel et al (2007). No other data was assimilated to isolate the effects of the time-evolving chlorophyll field. The daily MODIS Kd_PAR product was used to validate the skill of the penetration depth estimation and the MERRA-OCEAN re-analysis was used as a benchmark to study the sensitivity of the upper ocean heat content and vertical temperature distribution to the chlorophyll input. In the experiment with daily chlorophyll data assimilation, the penetration depth was estimated more accurately, especially in the tropics. As a result, the temperature bias of the model was reduced. A notably robust albeit small (2-5 percent) improvement was found across the equatorial Pacific ocean, which is a critical region for seasonal to inter-annual prediction.

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

Science.gov (United States)

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

2017-06-01

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

Communicating Ocean Sciences to Informal Audiences (COSIA): Universities, Oceanographic Institutions, Science Centers and Aquariums Working Together to Improve Ocean Education and Public Outreach

Science.gov (United States)

Glenn, S.; McDonnell, J.; Halversen, C.; Zimmerman, T.; Ingram, L.

2007-12-01

Ocean observatories have already demonstrated their ability to maintain long-term time series, capture episodic events, provide context for improved shipboard sampling, and improve accessibility to a broader range of participants. Communicating Ocean Sciences, an already existing college course from COSEE-California has demonstrated its ability to teach future scientists essential communication skills. The NSF-funded Communicating Ocean Sciences to Informal Audiences (COSIA) project has leveraged these experiences and others to demonstrate a long-term model for promoting effective science communication skills and techniques applicable to diverse audiences. The COSIA effort is one of the pathfinders for ensuring that the new scientific results from the increasing U.S. investments in ocean observatories is effectively communicated to the nation, and will serve as a model for other fields. Our presentation will describe a long-term model for promoting effective science communication skills and techniques applicable to diverse audiences. COSIA established partnerships between informal science education institutions and universities nationwide to facilitate quality outreach by scientists and the delivery of rigorous, cutting edge science by informal educators while teaching future scientists (college students) essential communication skills. The COSIA model includes scientist-educator partnerships that develop and deliver a college course that teaches communication skills through the understanding of learning theory specifically related to informal learning environments and the practice of these skills at aquariums and science centers. The goals of COSIA are to: provide a model for establishing substantive, long-term partnerships between scientists and informal science education institutions to meet their respective outreach needs; provide future scientists with experiences delivering outreach and promoting the broader impact of research; and provide diverse role models

Ocean acidification postcards

Science.gov (United States)

Schreppel, Heather A.; Cimitile, Matthew J.

2011-01-01

The U.S. Geological Survey (USGS) is conducting research on ocean acidification in polar, temperate, subtropical, and tropical regions including the Arctic, West Florida Shelf, and the Caribbean. Project activities include field assessment, experimental laboratory studies, and evaluation of existing data. The USGS is participating in international and interagency working groups to develop research strategies to increase understanding of the global implications of ocean acidification. Research strategies include new approaches for seawater chemistry observation and modeling, assessment of physiological effects on organisms, changes in marine ecosystem structure, new technologies, and information resources. These postcards highlight ongoing USGS research efforts in ocean acidification and carbon cycling in marine and coastal ecosystems in three different regions: polar, temperate, and tropical. To learn more about ocean acidification visit: http://coastal.er.usgs.gov/ocean-acidification/.

Decadal climate predictability in the southern Indian Ocean captured by SINTEX-F using a simple SST-nudging scheme.

Science.gov (United States)

Morioka, Yushi; Doi, Takeshi; Behera, Swadhin K

2018-01-26

Decadal climate variability in the southern Indian Ocean has great influences on southern African climate through modulation of atmospheric circulation. Although many efforts have been made to understanding physical mechanisms, predictability of the decadal climate variability, in particular, the internally generated variability independent from external atmospheric forcing, remains poorly understood. This study investigates predictability of the decadal climate variability in the southern Indian Ocean using a coupled general circulation model, called SINTEX-F. The ensemble members of the decadal reforecast experiments were initialized with a simple sea surface temperature (SST) nudging scheme. The observed positive and negative peaks during late 1990s and late 2000s are well reproduced in the reforecast experiments initiated from 1994 and 1999, respectively. The experiments initiated from 1994 successfully capture warm SST and high sea level pressure anomalies propagating from the South Atlantic to the southern Indian Ocean. Also, the other experiments initiated from 1999 skillfully predict phase change from a positive to negative peak. These results suggest that the SST-nudging initialization has the essence to capture the predictability of the internally generated decadal climate variability in the southern Indian Ocean.

NWFSC OA facility water chemistry - Ocean acidification species exposure experimental facility

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — We have developed a unique facility for conducting high-quality experiments on marine organisms in seawater with controlled carbon chemistry conditions. The...

Radioisotope studies on the paradox in dispersion and agglomeration of sewage greases discharged from ocean outfalls

International Nuclear Information System (INIS)

Davison, A.; Easy, J.F.; Seatonberry, B.W.

1981-04-01

Experiments have been undertaken in the ocean off Sydney, Australia to monitor the movement and the dispersion of sewage solids. These solids were labelled with a radioisotope, gold-198 prior to ocean discharge. The labelled material was followed at sea using submersible scintillation detectors. Lateral and vertical dispersion coefficients were determined. The experiments showed that under some conditions the labelled sewage grease dispersed and under others the grease agglomerated. This variation is explained in terms of non-conservative processes

Spacebased Observation of Water Balance Over Global Oceans

Science.gov (United States)

Liu, W.; Xie, X.

2008-12-01

We demonstrated that ocean surface fresh water flux less the water discharge into the ocean from river and ice melt balances the mass loss in the ocean both in magnitude and in the phase of annual variation. The surface water flux was computed from the divergence of the water transport integrated over the depth of the atmosphere. The atmospheric water transport is estimated from the precipitable water measured by Special Sensor Microwave Imager, the surface wind vector by QuikSCAT, and the NOAA cloud drift wind through a statistical model. The transport has been extensively validated using global radiosonde and data and operational numerical weather prediction results. Its divergence has been shown to agree with the difference between evaporation estimated from the Advanced Microwave Scanning Radiometer data and the precipitation measured by Tropical Rain Measuring Mission over the global tropical and subtropical oceans both in magnitude and geographical distribution for temporal scales ranging from intraseasonal to interannual. The water loss rate in the ocean is estimated by two methods, one is from Gravity Recovery and Climate Experiment and the other is by subtracting the climatological steric change from the sea level change measured by radar altimeter on Jason. Only climatological river discharge and ice melt from in situ measurements are available and the lack of temporal variation may contribute to discrepancies in the balance. We have successfully used the spacebased surface fluxes to estimate to climatological mean heat transport in the Atlantic ocean and is attempting to estimate the meridional fresh water (or salt) transport from the surface flux. The approximate closure of the water balance gives a powerful indirect validation of the spacebased products.

Simulating and understanding the gap outflow and oceanic response over the Gulf of Tehuantepec during GOTEX

Science.gov (United States)

Hong, Xiaodong; Peng, Melinda; Wang, Shouping; Wang, Qing

2018-06-01

Tehuantepecer is a strong mountain gap wind traveling through Chivela Pass into eastern Pacific coast in southern Mexico, most commonly between October and February and brings huge impacts on local and surrounding meteorology and oceanography. Gulf of Tehuantepec EXperiment (GOTEX) was conducted in February 2004 to enhance the understanding of the strong offshore gap wind, ocean cooling, vertical circulations and interactions among them. The gap wind event during GOTEX was simulated using the U.S. Navy Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®). The simulations are compared and validated with the observations retrieved from several satellites (GOES 10-12, MODIS/Aqua/Terra, TMI, and QuikSCAT) and Airborne EXpendable BathyThermograph (AXBT). The study shows that the gap wind outflow has a fanlike pattern expending from the coast and with a strong diurnal variability. The surface wind stress and cooling along the axis of the gap wind outflow caused intense upwelling and vertical mixing in the upper ocean; both contributed to the cooling of the ocean mixed layer under the gap wind. The cooling pattern of sea surface temperature (SST) also reflects temperature advection by the nearby ocean eddies to have a crescent shape. Two sensitivity experiments were conducted to understand the relative roles of the wind stress and heat flux on the ocean cooling. The control has more cooling right under the gap flow region than either the wind-stress-only or the heat-flux-only experiment. Overall, the wind stress has a slightly larger effect in bringing down the ocean temperature near the surface and plays a more important role in local ocean circulations beneath the mixed layer. The impact of surface heat flux on the ocean is more limited to the top 30 m within the mixed layer and is symmetric to the gap flow region by cooling the ocean under the gap flow region and reducing the warming on both sides. The effect of surface wind stress is to induce more cooling

Climate Ocean Modeling on a Beowulf Class System

Science.gov (United States)

Cheng, B. N.; Chao, Y.; Wang, P.; Bondarenko, M.

2000-01-01

With the growing power and shrinking cost of personal computers. the availability of fast ethernet interconnections, and public domain software packages, it is now possible to combine them to build desktop parallel computers (named Beowulf or PC clusters) at a fraction of what it would cost to buy systems of comparable power front supercomputer companies. This led as to build and assemble our own sys tem. specifically for climate ocean modeling. In this article, we present our experience with such a system, discuss its network performance, and provide some performance comparison data with both HP SPP2000 and Cray T3E for an ocean Model used in present-day oceanographic research.

Ejecta from Ocean Impacts

Science.gov (United States)

Kyte, Frank T.

2003-01-01

Numerical simulations of deep-ocean impact provide some limits on the size of a projectile that will not mix with the ocean floor during a deep-ocean impact. For a vertical impact at asteroidal velocities (approx. 20 km/s), mixing is only likely when the projectile diameter is greater than 112 of the water depth. For oblique impacts, even larger projectiles will not mix with ocean floor silicates. Given the typical water depths of 4 to 5 km in deep-ocean basins, asteroidal projectiles with diameters as large as 2 or 3 km may commonly produce silicate ejecta that is composed only of meteoritic materials and seawater salts. However, the compressed water column beneath the projectile can still disrupt and shock metamorphose the ocean floor. Therefore, production of a separate, terrestrial ejecta component is not ruled out in the most extreme case. With increasing projectile size (or energy) relative to water depths, there must be a gradation between oceanic impacts and more conventional continental impacts. Given that 60% of the Earth's surface is covered by oceanic lithosphere and 500 m projectiles impact the Earth on 10(exp 5) y timescales, there must be hundreds of oceanic impact deposits in the sediment record awaiting discovery.

Current measurements from acoustic doppler current profilers (ADCP) in the southwest Atlantic Ocean from the World Ocean Circulation Experiment (WOCE) from 1991-01-03 to 1992-11-26 (NODC Accession 0087597)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data from the ADCP instruments of BE/335 and BW/333 from January 3, 1991 to November 26, 1992 collected as part of the World Ocean Circulation...

Ocean acidification

National Research Council Canada - National Science Library

Gattuso, J.P; Hansson, L

2011-01-01

The fate of much of the CO 2 we produce will be to enter the ocean. In a sense, we are fortunate that ocean water is endowed with the capacity to absorb far more CO 2 per litre than were it salt free...

Increased exposure of Southern Ocean phytoplankton to ultraviolet radiation

Science.gov (United States)

Lubin, Dan; Arrigo, Kevin R.; van Dijken, Gert L.

2004-05-01

Satellite remote sensing of both surface solar ultraviolet radiation (UVR) and chlorophyll over two decades shows that biologically significant ultraviolet radiation increases began to occur over the Southern Ocean three years before the ozone ``hole'' was discovered. Beginning in October 1983, the most frequent occurrences of enhanced UVR over phytoplankton-rich waters occurred in the Weddell Sea and Indian Ocean sectors of the Southern Ocean, impacting 60% of the surface biomass by the late 1990s. These results suggest two reasons why more serious impacts to the base of the marine food web may not have been detected by field experiments: (1) the onset of UVR increases several years before dedicated field work began may have impacted the most sensitive organisms long before such damage could be detected, and (2) most biological field work has so far not taken place in Antarctic waters most extensively subjected to enhanced UVR.

Using Deep-Sea Scientific Drilling to Enhance Ocean Science Literacy

Science.gov (United States)

Passow, Michael; Cooper, Sharon; Kurtz, Nicole; Burgio, Marion; Cicconi, Alessia

2017-04-01

Beginning with confirmation of sea floor spreading in Leg 3 of the Deep Sea Drilling Project in 1968, scientific ocean drilling has provided much of the evidence supporting modern understanding of the Earth System, global climate changes, and many other important concepts. But for more than three decades, results of discoveries were published primarily in scientific journals and cruise volumes. On occasion, science journalists would write articles for the general public, but organized educational outreach efforts were rare. Starting about a decade ago, educators were included in the scientific party aboard the JOIDES Resolution. These "teachers-at-sea" developed formats to translate the technical and scientific activities into language understandable to students, teachers, and the public. Several "Schools of Rock" have enabled groups of teachers and informal science educators to experience what happens aboard the JOIDES Resolution. Over the past few years, educational outreach efforts based on scientific drilling expanded to create a large body of resources that promote Ocean Science Literacy. Partnerships between scientists and educators have produced a searchable database of inquiry-centered classroom and informal science activities. These are available for free through the JOIDES Resolution website, joidesresolution.org. Activities are aligned with the Ocean Literacy Principles (http://oceanliteracy.wp2.coexploration.org/) and Science Education Standards. In addition to a suite of lessons based on the science behind scientific drilling, participants have developed a range of educational resources that include graphic novels ("Tales of the Resolution" (http://joidesresolution.org/node/263) ; children's books ("Uncovering Earth's Secrets" and "Where the Wild Microbes Grow" http://joidesresolution.org/node/2998); posters, videos, and other materials. Cooper and Kurtz are currently overseeing improvements and revisions to the JR education website pages. The

Marine ecosystem community carbon and nutrient uptake stoichiometry under varying ocean acidification during the PeECE III experiment

Directory of Open Access Journals (Sweden)

R. G. J. Bellerby

2008-11-01

Full Text Available Changes to seawater inorganic carbon and nutrient concentrations in response to the deliberate CO₂ perturbation of natural plankton assemblages were studied during the 2005 Pelagic Ecosystem CO₂ Enrichment (PeECE III experiment. Inverse analysis of the temporal inorganic carbon dioxide system and nutrient variations was used to determine the net community stoichiometric uptake characteristics of a natural pelagic ecosystem perturbed over a range of pCO₂ scenarios (350, 700 and 1050 μatm. Nutrient uptake showed no sensitivity to CO₂ treatment. There was enhanced carbon production relative to nutrient consumption in the higher CO₂ treatments which was positively correlated with the initial CO₂ concentration. There was no significant calcification response to changing CO₂ in Emiliania huxleyi by the peak of the bloom and all treatments exhibited low particulate inorganic carbon production (~15 μmol kg⁻¹. With insignificant air-sea CO₂ exchange across the treatments, the enhanced carbon uptake was due to increase organic carbon production. The inferred cumulative C:N:P stoichiometry of organic production increased with CO₂ treatment from 1:6.3:121 to 1:7.1:144 to 1:8.25:168 at the height of the bloom. This study discusses how ocean acidification may incur modification to the stoichiometry of pelagic production and have consequences for ocean biogeochemical cycling.

Oceanic Precondition and Evolution of the Indian Ocean Dipole Events

Science.gov (United States)

Horii, T.; Masumoto, Y.; Ueki, I.; Hase, H.; Mizuno, K.

2008-12-01

Indian Ocean Dipole (IOD) is one of the interannual climate variability in the Indian Ocean, associated with the negative (positive) SST anomaly in the eastern (western) equatorial region developing during boreal summer/autumn seasons. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been deploying TRITON buoys in the eastern equatorial Indian Ocean since October 2001. Details of subsurface ocean conditions associated with IOD events were observed by the mooring buoys in the eastern equatorial Indian Ocean in 2006, 2007, and 2008. In the 2006 IOD event, large-scale sea surface signals in the tropical Indian Ocean associated with the positive IOD started in August 2006, and the anomalous conditions continued until December 2006. Data from the mooring buoys, however, captured the first appearance of the negative temperature anomaly at the thermocline depth with strong westward current anomalies in May 2006, about three months earlier than the development of the surface signatures. Similar appearance of negative temperature anomalies in the subsurface were also observed in 2007 and 2008, while the amplitude, the timing, and the relation to the surface layer were different among the events. The implications of the subsurface conditions for the occurrences of these IOD events are discussed.

Remote sensing for global change, climate change and atmosphere and ocean forecasting. Volume 1

International Nuclear Information System (INIS)

1992-01-01

This volume is separated in three sessions. First part is on remote sensing for global change (with global modelling, land cover change on global scale, ocean colour studies of marine biosphere, biological and hydrological interactions and large scale experiments). Second part is on remote sensing for climate change (with earth radiation and clouds, sea ice, global climate research programme). Third part is on remote sensing for atmosphere and ocean forecasting (with temperatures and humidity, winds, data assimilation, cloud imagery, sea surface temperature, ocean waves and topography). (A.B.). refs., figs., tabs

Deglacial Millennial-scale Calcium Carbonate Spikes in the North Pacific Ocean

Science.gov (United States)

Chikamoto, M. O.; Timmermann, A.; Harada, N.; Okazaki, Y.

2015-12-01

Numerous paleoproxy records from the subarctic Pacific Ocean show two very pronounced deglacial peaks in calcium carbonate content for the Heinrich 1/ Bolling-Allerod (H1-BA) transition (at 14 ka) and for the Younger Dryas/Preboreal transition (at 11 ka). Focusing on the H1-BA transition, some model simulations capture the North Pacific shift from ventilated to stratified conditions and from cooling to warming conditions via oceanic and atmospheric connections between Atlantic and Pacific Oceans. To test the impact of these physical scenarios (variations in ocean stratification and temperature during the H1-BA transition) on calcite production or preservation, we conduct a series of idealized experiments using the Earth System Model Intermediate Complexity LOVECLIM. The variations in North Pacific Ocean stratification by anomalous freshwater forcing show low calcite productivity in associated with the subsurface nutrient decline. On the other hand, the rapid H1-BA warming of the North Pacific Ocean induced by anomalous heat forcing in turn increases calcite productivity due to the temperature-dependent growth rate of phytoplankton. These results suggest the possibility that the millennial-scale calcium carbonate peaks are the result of surface biogeochemical responses to the climate transition, not by the deep circulation response.

High-precision GNSS ocean positioning with BeiDou short-message communication

Science.gov (United States)

Li, Bofeng; Zhang, Zhiteng; Zang, Nan; Wang, Siyao

2018-04-01

The current popular GNSS RTK technique would be not applicable on ocean due to the limited communication access for transmitting differential corrections. A new technique is proposed for high-precision ocean RTK, referred to as ORTK, where the corrections are transmitted by employing the function of BeiDou satellite short-message communication (SMC). To overcome the limitation of narrow bandwidth of BeiDou SMC, a new strategy of simplifying and encoding corrections is proposed instead of standard differential corrections, which reduces the single-epoch corrections from more than 1000 to less than 300 bytes. To solve the problems of correction delays, cycle slips, blunders and abnormal epochs over ultra-long baseline ORTK, a series of powerful algorithms were designed at the user-end software for achieving the stable and precise kinematic solutions on far ocean applications. The results from two long baselines of 240 and 420 km and real ocean experiments reveal that the kinematic solutions with horizontal accuracy of 5 cm and vertical accuracy of better than 15 cm are achievable by convergence time of 3-10 min. Compared to commercial ocean PPP with satellite telecommunication, ORTK is of much cheaper expense, higher accuracy and shorter convergence. It will be very prospective in many location-based ocean services.

Naturally acidified habitat selects for ocean acidification-tolerant mussels.

Science.gov (United States)

Thomsen, Jörn; Stapp, Laura S; Haynert, Kristin; Schade, Hanna; Danelli, Maria; Lannig, Gisela; Wegner, K Mathias; Melzner, Frank

2017-04-01

Ocean acidification severely affects bivalves, especially their larval stages. Consequently, the fate of this ecologically and economically important group depends on the capacity and rate of evolutionary adaptation to altered ocean carbonate chemistry. We document successful settlement of wild mussel larvae ( Mytilus edulis ) in a periodically CO 2 -enriched habitat. The larval fitness of the population originating from the CO 2 -enriched habitat was compared to the response of a population from a nonenriched habitat in a common garden experiment. The high CO 2 -adapted population showed higher fitness under elevated P co 2 (partial pressure of CO 2 ) than the non-adapted cohort, demonstrating, for the first time, an evolutionary response of a natural mussel population to ocean acidification. To assess the rate of adaptation, we performed a selection experiment over three generations. CO 2 tolerance differed substantially between the families within the F 1 generation, and survival was drastically decreased in the highest, yet realistic, P co 2 treatment. Selection of CO 2 -tolerant F 1 animals resulted in higher calcification performance of F 2 larvae during early shell formation but did not improve overall survival. Our results thus reveal significant short-term selective responses of traits directly affected by ocean acidification and long-term adaptation potential in a key bivalve species. Because immediate response to selection did not directly translate into increased fitness, multigenerational studies need to take into consideration the multivariate nature of selection acting in natural habitats. Combinations of short-term selection with long-term adaptation in populations from CO 2 -enriched versus nonenriched natural habitats represent promising approaches for estimating adaptive potential of organisms facing global change.

Regional impacts of ocean color on tropical Pacific variability

Directory of Open Access Journals (Sweden)

W. Anderson

2009-08-01

Full Text Available The role of the penetration length scale of shortwave radiation into the surface ocean and its impact on tropical Pacific variability is investigated with a fully coupled ocean, atmosphere, land and ice model. Previous work has shown that removal of all ocean color results in a system that tends strongly towards an El Niño state. Results from a suite of surface chlorophyll perturbation experiments show that the mean state and variability of the tropical Pacific is highly sensitive to the concentration and distribution of ocean chlorophyll. Setting the near-oligotrophic regions to contain optically pure water warms the mean state and suppresses variability in the western tropical Pacific. Doing the same above the shadow zones of the tropical Pacific also warms the mean state but enhances the variability. It is shown that increasing penetration can both deepen the pycnocline (which tends to damp El Niño while shifting the mean circulation so that the wind response to temperature changes is altered. Depending on what region is involved this change in the wind stress can either strengthen or weaken ENSO variability.

Consensuses and discrepancies of basin-scale ocean heat content changes in different ocean analyses

Science.gov (United States)

Wang, Gongjie; Cheng, Lijing; Abraham, John; Li, Chongyin

2018-04-01

Inconsistent global/basin ocean heat content (OHC) changes were found in different ocean subsurface temperature analyses, especially in recent studies related to the slowdown in global surface temperature rise. This finding challenges the reliability of the ocean subsurface temperature analyses and motivates a more comprehensive inter-comparison between the analyses. Here we compare the OHC changes in three ocean analyses (Ishii, EN4 and IAP) to investigate the uncertainty in OHC in four major ocean basins from decadal to multi-decadal scales. First, all products show an increase of OHC since 1970 in each ocean basin revealing a robust warming, although the warming rates are not identical. The geographical patterns, the key modes and the vertical structure of OHC changes are consistent among the three datasets, implying that the main OHC variabilities can be robustly represented. However, large discrepancies are found in the percentage of basinal ocean heating related to the global ocean, with the largest differences in the Pacific and Southern Ocean. Meanwhile, we find a large discrepancy of ocean heat storage in different layers, especially within 300-700 m in the Pacific and Southern Oceans. Furthermore, the near surface analysis of Ishii and IAP are consistent with sea surface temperature (SST) products, but EN4 is found to underestimate the long-term trend. Compared with ocean heat storage derived from the atmospheric budget equation, all products show consistent seasonal cycles of OHC in the upper 1500 m especially during 2008 to 2012. Overall, our analyses further the understanding of the observed OHC variations, and we recommend a careful quantification of errors in the ocean analyses.

Impacts of pre-existing ocean cyclonic circulation on sea surface chlorophyll-a concentrations off northeastern Taiwan following episodic typhoon passages

Science.gov (United States)

Xu, Fanghua; Yao, Yuan; Oey, Leo; Lin, Yanluan

2017-08-01

Off northeastern Taiwan, enhancement of sea surface chlorophyll-a (Chl-a) concentration is frequently found after typhoon passages. From 1998 to 2013, 46 typhoon events are analyzed to examine the variations in Chl-a concentration from satellite ocean color data. On average, Chl-a concentration increased by 38% after a typhoon passage. Noticeably, four remarkable Chl-a increases after typhoons coincide with pre-existing oceanic cyclones in the study area. The Chl-a increase is significantly anticorrelated (p typhoons, we conduct a series of numerical experiments to simulate the oceanic response to Typhoon Kaemi (2006) with or without a pre-existing oceanic cyclone, and with or without strong typhoon winds. The results show that the experiment with a pre-existing oceanic cyclone produces the largest upwelling due to cyclone intensification, mainly induced by the positive wind stress curl dipole northeast of Taiwan.

Evaluation of Release-05 GRACE time-variable gravity coefficients over the ocean

Directory of Open Access Journals (Sweden)

D. P. Chambers

2012-10-01

Full Text Available The latest release of GRACE (Gravity Recovery and Climate Experiment gravity field coefficients (Release-05, or RL05 are evaluated for ocean applications. Data have been processed using the current methodology for Release-04 (RL04 coefficients, and have been compared to output from two different ocean models. Results indicate that RL05 data from the three Science Data Centers – the Center for Space Research (CSR, GeoForschungsZentrum (GFZ, and Jet Propulsion Laboratory (JPL – are more consistent among themselves than the previous RL04 data. Moreover, the variance of residuals with the output of an ocean model is 50–60% lower for RL05 data than for RL04 data. A more optimized destriping algorithm is also tested, which improves the results slightly. By comparing the GRACE maps with two different ocean models, we can better estimate the uncertainty in the RL05 maps. We find the standard error to be about 1 cm (equivalent water thickness in the low- and mid-latitudes, and between 1.5 and 2 cm in the polar and subpolar oceans, which is comparable to estimated uncertainty for the output from the ocean models.

Ocean Observations of Climate Change

Science.gov (United States)

Chambers, Don

2016-01-01

The ocean influences climate by storing and transporting large amounts of heat, freshwater, and carbon, and exchanging these properties with the atmosphere. About 93% of the excess heat energy stored by the earth over the last 50 years is found in the ocean. More than three quarters of the total exchange of water between the atmosphere and the earth's surface through evaporation and precipitation takes place over the oceans. The ocean contains 50 times more carbon than the atmosphere and is at present acting to slow the rate of climate change by absorbing one quarter of human emissions of carbon dioxide from fossil fuel burning, cement production, deforestation and other land use change.Here I summarize the observational evidence of change in the ocean, with an emphasis on basin- and global-scale changes relevant to climate. These include: changes in subsurface ocean temperature and heat content, evidence for regional changes in ocean salinity and their link to changes in evaporation and precipitation over the oceans, evidence of variability and change of ocean current patterns relevant to climate, observations of sea level change and predictions over the next century, and biogeochemical changes in the ocean, including ocean acidification.

Meteorological conditions in a thinner Arctic sea ice regime from winter to summer during the Norwegian Young Sea Ice expedition (N-ICE2015)

Science.gov (United States)

Cohen, Lana; Hudson, Stephen R.; Walden, Von P.; Graham, Robert M.; Granskog, Mats A.

2017-07-01

Atmospheric measurements were made over Arctic sea ice north of Svalbard from winter to early summer (January-June) 2015 during the Norwegian Young Sea Ice (N-ICE2015) expedition. These measurements, which are available publicly, represent a comprehensive meteorological data set covering the seasonal transition in the Arctic Basin over the new, thinner sea ice regime. Winter was characterized by a succession of storms that produced short-lived (less than 48 h) temperature increases of 20 to 30 K at the surface. These storms were driven by the hemispheric scale circulation pattern with a large meridional component of the polar jet stream steering North Atlantic storms into the high Arctic. Nonstorm periods during winter were characterized by strong surface temperature inversions due to strong radiative cooling ("radiatively clear state"). The strength and depth of these inversions were similar to those during the Surface Heat Budget of the Arctic Ocean (SHEBA) campaign. In contrast, atmospheric profiles during the "opaquely cloudy state" were different to those from SHEBA due to differences in the synoptic conditions and location within the ice pack. Storm events observed during spring/summer were the result of synoptic systems located in the Barents Sea and the Arctic Basin rather than passing directly over N-ICE2015. These synoptic systems were driven by a large-scale circulation pattern typical of recent years, with an Arctic Dipole pattern developing during June. Surface temperatures became near-constant 0°C on 1 June marking the beginning of summer. Atmospheric profiles during the spring and early summer show persistent lifted temperature and moisture inversions that are indicative of clouds and cloud processes.

Ocean Uses: Hawaii (PROUA)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This Pacific Regional Ocean Uses Atlas (PROUA) Project is an innovative partnership between NOAA and the Bureau of Ocean Energy Management (BOEM) designed to...

Nutrient co-limitation at the boundary of an oceanic gyre

Science.gov (United States)

Browning, Thomas J.; Achterberg, Eric P.; Rapp, Insa; Engel, Anja; Bertrand, Erin M.; Tagliabue, Alessandro; Moore, C. Mark

2017-11-01

Nutrient limitation of oceanic primary production exerts a fundamental control on marine food webs and the flux of carbon into the deep ocean. The extensive boundaries of the oligotrophic sub-tropical gyres collectively define the most extreme transition in ocean productivity, but little is known about nutrient limitation in these zones. Here we present the results of full-factorial nutrient amendment experiments conducted at the eastern boundary of the South Atlantic gyre. We find extensive regions in which the addition of nitrogen or iron individually resulted in no significant phytoplankton growth over 48 hours. However, the addition of both nitrogen and iron increased concentrations of chlorophyll a by up to approximately 40-fold, led to diatom proliferation, and reduced community diversity. Once nitrogen-iron co-limitation had been alleviated, the addition of cobalt or cobalt-containing vitamin B12 could further enhance chlorophyll a yields by up to threefold. Our results suggest that nitrogen-iron co-limitation is pervasive in the ocean, with other micronutrients also approaching co-deficiency. Such multi-nutrient limitations potentially increase phytoplankton community diversity.

The impact of wind energy turbine piles on ocean dynamics

Science.gov (United States)

Grashorn, Sebastian; Stanev, Emil V.

2016-04-01

The small- and meso-scale ocean response to wind parks has not been investigated in the southern North Sea until now with the help of high-resolution numerical modelling. Obstacles such as e.g. wind turbine piles may influence the ocean current system and produce turbulent kinetic energy which could affect sediment dynamics in the surrounding area. Two setups of the unstructured-grid model SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) have been developed for an idealized channel including a surface piercing cylindrical obstacle representing the pile and a more realistic test case including four exemplary piles. Experiments using a constant flow around the obstacles and a rotating M2 tidal wave are carried out. The resulting current and turbulence patterns are investigated to estimate the influence of the obstacles on the surrounding ocean dynamics. We demonstrate that using an unstructured ocean model provides the opportunity to embed a high-resolution representation of a wind park turbine pile system into a coarser North Sea setup, which is needed in order to perform a seamless investigation of the resulting geophysical processes.

Coupled model of INM-IO global ocean model, CICE sea ice model and SCM OIAS framework

Science.gov (United States)

Bayburin, Ruslan; Rashit, Ibrayev; Konstantin, Ushakov; Vladimir, Kalmykov; Gleb, Dyakonov

2015-04-01

Status of coupled Arctic model of ocean and sea ice is presented. Model consists of INM IO global ocean component of high resolution, Los Alamos National Laboratory CICE sea ice model and a framework SCM OIAS for the ocean-ice-atmosphere-land coupled modeling on massively-parallel architectures. Model is currently under development at the Institute of Numerical Mathematics (INM), Hydrometeorological Center (HMC) and P.P. Shirshov Institute of Oceanology (IO). Model is aimed at modeling of intra-annual variability of hydrodynamics in Arctic and. The computational characteristics of the world ocean-sea ice coupled model governed by SCM OIAS are presented. The model is parallelized using MPI technologies and currently can use efficiently up to 5000 cores. Details of programming implementation, computational configuration and physical phenomena parametrization are analyzed in terms of intercoupling complex. Results of five year computational experiment of sea ice, snow and ocean state evolution in Arctic region on tripole grid with horizontal resolution of 3-5 kilometers, closed by atmospheric forcing field from repeating "normal" annual course taken from CORE1 experiment data base are presented and analyzed in terms of the state of vorticity and warm Atlantic water expansion.

A System of Oceanic Reanalysis (SOR) fot the Nordic Seas

Science.gov (United States)

Pnyushkov, A.

2009-04-01

A system of oceanic reanalysis of the Nordic seas (Norwegian, Greenland and Barents seas) directed to the investigations of long period changes in the oceanic climate of the Arctic sub-polar seas was developed. The system of oceanic reanalysys (SOR) includes hybrid coordinate 22-th level ocean model HYCOM [Bleck,2002] and modern oceanographic data assimilation technique based on spectral nudging method. A series of test experiments was carried out and optimal parameters for assimilation routine were choused. These parameters take into account the accuracy of spatial restoring by means objective analysis procedure and phase distortion in modeling fields during monotonous assimilation of monthly distributions. On the basis of modeling results a set of monthly mean hydrological distributions of thermohaline parameters was created for the Nordic seas that was used for climatic field compilations on the standard levels for period 1957-1990. The data of reanalysis system projections allow us to restore the information about structure and dynamic of oceanographic fields for the periods and areas with a small number of direct measurements, for example East-Greenland currents area, north and north-east parts of the Barents sea. A series of additional experiments with SOR were performed directed to the simple assimilation of sea ice concentration data. A significant improvement of the system of objectively analyzed field preparation was done during 2008 including additional validation procedure of gridded arrays with using the direct data of oceanographic stations. This work was supported by Russian Foundation for Basic Research (grant 07-05-00393).

Spatial distribution of meteorological parameters around 900 hPa level over the Arabian Sea and Indian Ocean regions during the IFP-99 of the INDOEX programme as revealed from the constant altitude balloon experiments conducted from Goa

Digital Repository Service at National Institute of Oceanography (India)

Appu, K.S.; Nair, S.M.; Kunhikrishnan, P.K.; Moorthy, K.K.; Sarode, P.R.; Rao, L.V.G.; Bajpai, S.R.; Prakash, L.H.; Viswanathan, G.; Mitra, A.P.; Sadourny, R.; Basdevant, C.; Ethe, C.; Ovarlez, H.; Chapuis, R.; Dartiguelongue, B.; Vianeys, P.

of the payload Operational life Electric power Helium ~ 900 hPa 100?5hPa 1350?20g ~3kg ~3kg Several days to a week Lithium batteries INDIAN OCEAN EXPERIMENT duct such experiments as was demonstrated from the balloon flights carried out during the FFP-98...

Cloud-Scale Numerical Modeling of the Arctic Boundary Layer

Science.gov (United States)

Krueger, Steven K.

1998-01-01

The interactions between sea ice, open ocean, atmospheric radiation, and clouds over the Arctic Ocean exert a strong influence on global climate. Uncertainties in the formulation of interactive air-sea-ice processes in global climate models (GCMs) result in large differences between the Arctic, and global, climates simulated by different models. Arctic stratus clouds are not well-simulated by GCMs, yet exert a strong influence on the surface energy budget of the Arctic. Leads (channels of open water in sea ice) have significant impacts on the large-scale budgets during the Arctic winter, when they contribute about 50 percent of the surface fluxes over the Arctic Ocean, but cover only 1 to 2 percent of its area. Convective plumes generated by wide leads may penetrate the surface inversion and produce condensate that spreads up to 250 km downwind of the lead, and may significantly affect the longwave radiative fluxes at the surface and thereby the sea ice thickness. The effects of leads and boundary layer clouds must be accurately represented in climate models to allow possible feedbacks between them and the sea ice thickness. The FIRE III Arctic boundary layer clouds field program, in conjunction with the SHEBA ice camp and the ARM North Slope of Alaska and Adjacent Arctic Ocean site, will offer an unprecedented opportunity to greatly improve our ability to parameterize the important effects of leads and boundary layer clouds in GCMs.

Ocean fertilization with iron: effects on climate and air quality

International Nuclear Information System (INIS)

Liss, Peter; Chuck, Adele; Bakker, Dorothee; Turner, Suzanne

2005-01-01

It is well known that iron fertilization can increase primary production and hence CO 2 drawdown over a significant fraction of the oceans. What is less well established is the extent to which this leads to long-term sequestration of carbon to the deep oceans, and to feedbacks to the atmosphere arising from increased biological activity. In this note results for changes in trace gas concentrations during an iron addition experiment in the Southern Ocean are presented. They demonstrate that a complex situation exists; some gases (DMS, CH 3 I, CHBr 2 Cl) show increases in concentration following fertilization with iron while others show no change (CH 3 ONO 2 , CH 2 ClI) or even a decrease (CHBr 3 ). The concomitant effects on air/sea fluxes of these gases are potentially important for climate and atmospheric composition

OceanNOMADS: Real-time and retrospective access to operational U.S. ocean prediction products

Science.gov (United States)

Harding, J. M.; Cross, S. L.; Bub, F.; Ji, M.

2011-12-01

The National Oceanic and Atmospheric Administration (NOAA) National Operational Model Archive and Distribution System (NOMADS) provides both real-time and archived atmospheric model output from servers at the National Centers for Environmental Prediction (NCEP) and National Climatic Data Center (NCDC) respectively (http://nomads.ncep.noaa.gov/txt_descriptions/marRutledge-1.pdf). The NOAA National Ocean Data Center (NODC) with NCEP is developing a complementary capability called OceanNOMADS for operational ocean prediction models. An NCEP ftp server currently provides real-time ocean forecast output (http://www.opc.ncep.noaa.gov/newNCOM/NCOM_currents.shtml) with retrospective access through NODC. A joint effort between the Northern Gulf Institute (NGI; a NOAA Cooperative Institute) and the NOAA National Coastal Data Development Center (NCDDC; a division of NODC) created the developmental version of the retrospective OceanNOMADS capability (http://www.northerngulfinstitute.org/edac/ocean_nomads.php) under the NGI Ecosystem Data Assembly Center (EDAC) project (http://www.northerngulfinstitute.org/edac/). Complementary funding support for the developmental OceanNOMADS from U.S. Integrated Ocean Observing System (IOOS) through the Southeastern University Research Association (SURA) Model Testbed (http://testbed.sura.org/) this past year provided NODC the analogue that facilitated the creation of an NCDDC production version of OceanNOMADS (http://www.ncddc.noaa.gov/ocean-nomads/). Access tool development and storage of initial archival data sets occur on the NGI/NCDDC developmental servers with transition to NODC/NCCDC production servers as the model archives mature and operational space and distribution capability grow. Navy operational global ocean forecast subsets for U.S waters comprise the initial ocean prediction fields resident on the NCDDC production server. The NGI/NCDDC developmental server currently includes the Naval Research Laboratory Inter-America Seas

Educational Experiences in Oceanography through Hands-On Involvement with Surface Drifters: an Introduction to Ocean Currents, Engineering, Data Collection, and Computer Science

Science.gov (United States)

Anderson, T.

2015-12-01

The Northeast Fisheries Science Center's (NEFSC) Student Drifters Program is providing education opportunities for students of all ages. Using GPS-tracked ocean drifters, various educational institutions can provide students with hands-on experience in physical oceanography, engineering, and computer science. In building drifters many high school and undergraduate students may focus on drifter construction, sometimes designing their own drifter or attempting to improve current NEFSC models. While learning basic oceanography younger students can build drifters with the help of an educator and directions available on the studentdrifters.org website. Once drifters are deployed, often by a local mariner or oceanographic partner, drifter tracks can be visualised on maps provided at http://nefsc.noaa.gov/drifter. With the lesson plans available for those interested in computer science, students may download, process, and plot the drifter position data with basic Python code provided. Drifter tracks help students to visualize ocean currents, and also allow them to understand real particle tracking applications such as in search and rescue, oil spill dispersion, larval transport, and the movement of injured sea animals. Additionally, ocean circulation modelers can use student drifter paths to validate their models. The Student Drifters Program has worked with over 100 schools, several of them having deployed drifters on the West Coast. Funding for the program often comes from individual schools and small grants but in the future will preferably come from larger government grants. NSF, Sea-Grant, NOAA, and EPA are all possible sources of funding, especially with the support of multiple schools and large marine education associations. The Student Drifters Program is a unique resource for educators, students, and scientists alike.

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

Science.gov (United States)

2010-09-08

.... SUMMARY: The EPA is designating the Guam Deep Ocean Disposal Site (G- DODS) as a permanent ocean dredged... administration of ocean disposal permits; (2) development and maintenance of a site monitoring program; (3... include: (1) Regulating quantities and types of material to be disposed, including the time, rates, and...

AFSC/RACE/FBEP/Hurst: Effects of ocean acidification on hatch size and larval growth of walleye pollock (Theragra chalcogramma)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from laboratory experiments that examined the direct effects of projected levels of ocean acidification on the eggs and larvae of walleye pollock.

Oceanic Platform of the Canary Islands: an ocean testbed for ocean energy converters

Science.gov (United States)

González, Javier; Hernández-Brito, Joaquín.; Llinás, Octavio

2010-05-01

The Oceanic Platform of the Canary Islands (PLOCAN) is a Governmental Consortium aimed to build and operate an off-shore infrastructure to facilitate the deep sea research and speed up the technology associated. This Consortium is overseen by the Spanish Ministry of Science and Innovation and the Canarian Agency for Research and Innovation. The infrastructure consists of an oceanic platform located in an area with depths between 50-100 meters, close to the continental slope and four kilometers off the coast of Gran Canaria, in the archipelago of the Canary Islands. The process of construction will start during the first months of 2010 and is expected to be finished in mid-year 2011. PLOCAN serves five strategic lines: an integral observatory able to explore from the deep ocean to the atmosphere, an ocean technology testbed, a base for underwater vehicles, an innovation platform and a highly specialized training centre. Ocean energy is a suitable source to contribute the limited mix-energy conformed in the archipelago of the Canary Islands with a total population around 2 million people unequally distributed in seven islands. Islands of Gran Canaria and Tenerife support the 80% of the total population with 800.000 people each. PLOCAN will contribute to develop the ocean energy sector establishing a marine testbed allowing prototypes testing at sea under a meticulous monitoring network provided by the integral observatory, generating valuable information to developers. Reducing costs throughout an integral project management is an essential objective to be reach, providing services such as transportation, customs and administrative permits. Ocean surface for testing activities is around 8 km2 with a depth going from 50 to 100 meters, 4km off the coast. Selected areas for testing have off-shore wind power conditions around 500-600 W/m2 and wave power conditions around 6 kW/m in the East coast and 10 kW/m in the North coast. Marine currents in the Canary Islands are

Captivating Broad Audiences with an Internet-connected Ocean

Science.gov (United States)

Moran, K.; Elliott, L.; Gervais, F.; Juniper, K.; Owens, D.; Pirenne, B.

2012-12-01

NEPTUNE Canada, a network of Ocean Networks Canada and the first deep water cabled ocean observatory, began operations in December 2009. Located offshore Canada's west coast, the network streams data from passive, active, and interactive sensors positioned at five nodes along its 800 km long looped cable to the Internet. This technically advanced system includes a sophisticated data management and archiving system, which enables the collection of real-time physical, chemical, geological, and biological oceanographic data, including video, at resolutions relevant for furthering our understanding of the dynamics of the earth-ocean system. Scientists in Canada and around the world comprise the primary audience for these data, but NEPTUNE Canada is also serving these data to broader audiences including K-16 students and teachers, informal educators, citizen scientists, the press, and the public. Here we present our engagement tools, approaches, and experiences including electronic books, personal phone apps, Internet-served video, social media, mini-observatory systems, print media, live broadcasting from sea, and a citizen scientist portal.NEPTUNE Canada's ibook available on Apple's iBook store.

Regional Ocean Data Assimilation

KAUST Repository

Edwards, Christopher A.

2015-01-03

This article reviews the past 15 years of developments in regional ocean data assimilation. A variety of scientific, management, and safety-related objectives motivate marine scientists to characterize many ocean environments, including coastal regions. As in weather prediction, the accurate representation of physical, chemical, and/or biological properties in the ocean is challenging. Models and observations alone provide imperfect representations of the ocean state, but together they can offer improved estimates. Variational and sequential methods are among the most widely used in regional ocean systems, and there have been exciting recent advances in ensemble and four-dimensional variational approaches. These techniques are increasingly being tested and adapted for biogeochemical applications.

MERSEA, the European Gate to Ocean Data

Science.gov (United States)

Blanc, F. P.; Manzella, G.; Maudire, G.; Bahurel, P.; Bell, M.; Haines, K.

2004-12-01

Mersea ('Marine Environment and Security for the European Area'), a European project to manage the oceans, aims to develop by 2008 the GMES ocean component ('Global Monitoring for Environment and Security'), a system for operational monitoring and forecasting on global and regional scales of the ocean physics, bio-geochemistry and ecosystems. Mersea project started on April 1st, 2004. This ocean monitoring system is envisioned as an operational network that systematically acquires data and disseminates information to serve the needs of intermediate users and policy makers, in support of safe and efficient off-shore activities, environmental management, security, and sustainable use of marine resources. Three real-time data streams have been identified: remote sensed from satellites, in situ from ocean observing networks, and surface forcing fields from numerical weather prediction agencies. Mersea will ensure the availability of near real time and delayed mode products over the period 2004-2008, global and regional products optimised for supporting operational oceanography. Historical data sets for the last 15 years will also be prepared. Mersea is also the European center serving Godae goals ('Global Ocean Data Assimilation Experiment', 2003-2005). The timely delivery of high quality and reliable information to many user categories is essential for the success of such integrated project. There is consequently a large effort to coordinate all delivery actions giving special attention on the users' needs. This effort will cover many issues like product presentation, products and web services catalogue and how to deal for an interdisciplinary and integrated use. A first major difficulty is to reach at many levels product coherency and standardisation, which is needed to facilitate the visibility, understanding and exchange of the ocean observing data. A first task will therefore be to write a common unified framework guide, a kind of member chart, which will require

Mapping of lithologic and structural units using multispectral imagery. [Afar-Triangle/Ethiopia and adjacent areas (Ethiopian Plateau, Somali Plateau, and parts of Yemen and Saudi Arabia)

Science.gov (United States)

Kronberg, P. (Principal Investigator)

1974-01-01

The author has identified the following significant results. ERTS-1 MSS imagery covering the Afar-Triangle/Ethiopia and adjacent regions (Ethiopian Plateau, Somali Plateau, and parts of Yemen and Saudi Arabi) was applied to the mapping of lithologic and structural units of the test area at a scale 1:1,000,000. Results of the geological evaluation of the ERTS-1 imagery of the Afar have proven the usefullness of this type of satellite data for regional geological mapping. Evaluation of the ERTS images also resulted in new aspects of the structural setting and tectonic development of the Afar-Triangle, where three large rift systems, the oceanic rifts of the Red Sea and Gulf of Aden and the continental East African rift system, seem to meet each other. Surface structures mapped by ERTS do not indicate that the oceanic rift of the Gulf of Aden (Sheba Ridge) continues into the area of continental crust west of the Gulf of Tadjura. ERTS data show that the Wonji fault belt of the African rift system does not enter or cut through the central Afar. The Aysha-Horst is not a Horst but an autochthonous spur of the Somali Plateau.

Springer handbook of ocean engineering

CERN Document Server

Xiros, Nikolaos

2016-01-01

The handbook is the definitive reference for the interdisciplinary field that is ocean engineering. It integrates the coverage of fundamental and applied material and encompasses a diverse spectrum of systems, concepts and operations in the maritime environment, as well as providing a comprehensive update on contemporary, leading-edge ocean technologies. Coverage includes but is not limited to; an overview of ocean science, ocean signals and instrumentation, coastal structures, developments in ocean energy technologies, and ocean vehicles and automation. The handbook will be of interest to practitioners in a range of offshore industries and naval establishments as well as academic researchers and graduate students in ocean, coastal, offshore, and marine engineering and naval architecture.

Relocation of earthquakes at southwestern Indian Ocean Ridge and its tectonic significance

Science.gov (United States)

Luo, W.; Zhao, M.; Haridhi, H.; Lee, C. S.; Qiu, X.; Zhang, J.

2015-12-01

The southwest Indian Ridge (SWIR) is a typical ultra-slow spreading ridge (Dick et al., 2003) and further plate boundary where the earthquakes often occurred. Due to the lack of the seismic stations in SWIR, positioning of earthquakes and micro-earthquakes is not accurate. The Ocean Bottom Seismometers (OBS) seismic experiment was carried out for the first time in the SWIR 49 ° 39 'E from Jan. to March, 2010 (Zhao et al., 2013). These deployed OBS also recorded the earthquakes' waveforms during the experiment. Two earthquakes occurred respectively in Feb. 7 and Feb. 9, 2010 with the same magnitude of 4.4 mb. These two earthquakes were relocated using the software HYPOSAT based on the spectrum analysis and band-pass (3-5 Hz) filtering and picking up the travel-times of Pn and Sn. Results of hypocentral determinations show that there location error is decreased significantly by joined OBS's recording data. This study do not only provide the experiences for the next step deploying long-term wide-band OBSs, but also deepen understanding of the structure of SWIR and clarify the nature of plate tectonic motivation. This research was granted by the Natural Science Foundation of China (41176053, 91028002, 91428204). Keywords: southwest Indian Ridge (SWIR), relocation of earthquakes, Ocean Bottom Seismometers (OBS), HYPOSAT References:[1] Dick, H. J. B., Lin J., Schouten H. 2003. An ultraslow-spreading class of ocean ridge. Nature, 426(6965): 405-412. [2] Zhao M. H., et al. 2013. Three-dimensional seismic structure of the Dragon Flag oceanic core complex at the ultraslow spreading Southwest Indian Ridge (49°39' E). Geochemistry Geophysics Geosystems, 14(10): 4544-4563.

Response of Southern Ocean circulation to global warming may enhance basal ice shelf melting around Antarctica

Energy Technology Data Exchange (ETDEWEB)

Hattermann, Tore; Levermann, Anders [Potsdam University, Earth System Analysis, Potsdam Institute for Climate Impact Research, Potsdam (Germany)

2010-10-15

We investigate the large-scale oceanic features determining the future ice shelf-ocean interaction by analyzing global warming experiments in a coarse resolution climate model with a comprehensive ocean component. Heat and freshwater fluxes from basal ice shelf melting (ISM) are parameterized following Beckmann and Goosse [Ocean Model 5(2):157-170, 2003]. Melting sensitivities to the oceanic temperature outside of the ice shelf cavities are varied from linear to quadratic (Holland et al. in J Clim 21, 2008). In 1% per year CO{sub 2}-increase experiments the total freshwater flux from ISM triples to 0.09 Sv in the linear case and more than quadruples to 0.15 Sv in the quadratic case after 140 years at which 4 x 280 ppm = 1,120 ppm was reached. Due to the long response time of subsurface temperature anomalies, ISM thereafter increases drastically, if CO{sub 2} concentrations are kept constant at 1,120 ppm. Varying strength of the Antarctic circumpolar current (ACC) is crucial for ISM increase, because southward advection of heat dominates the warming along the Antarctic coast. On centennial timescales the ACC accelerates due to deep ocean warming north of the current, caused by mixing of heat along isopycnals in the Southern Ocean (SO) outcropping regions. In contrast to previous studies we find an initial weakening of the ACC during the first 150 years of warming. This purely baroclinic effect is due to a freshening in the SO which is consistent with present observations. Comparison with simulations with diagnosed ISM but without its influence on the ocean circulation reveal a number of ISM-related feedbacks, of which a negative ISM-feedback, due to the ISM-related local oceanic cooling, is the dominant one. (orig.)

EPOCA/EUR-OCEANS data compilation on the biological and biogeochemical responses to ocean acidification

NARCIS (Netherlands)

Nisumaa, A.-M.; Pesant, S.; Bellerby, R.G.J.; Delille, B.; Middelburg, J.J.; Orr, J.C.; Riebesell, U.; Tyrrell, T.; Wolf-Gladrow, D.; Gattuso, J.P.

2010-01-01

The uptake of anthropogenic CO2 by the oceans has led to a rise in the oceanic partial pressure of CO2, and to a decrease in pH and carbonate ion concentration. This modification of the marine carbonate system is referred to as ocean acidification. Numerous papers report the effects of ocean

Remote Sensing of Ocean Color

Science.gov (United States)

Dierssen, Heidi M.; Randolph, Kaylan

The oceans cover over 70% of the earth's surface and the life inhabiting the oceans play an important role in shaping the earth's climate. Phytoplankton, the microscopic organisms in the surface ocean, are responsible for half of the photosynthesis on the planet. These organisms at the base of the food web take up light and carbon dioxide and fix carbon into biological structures releasing oxygen. Estimating the amount of microscopic phytoplankton and their associated primary productivity over the vast expanses of the ocean is extremely challenging from ships. However, as phytoplankton take up light for photosynthesis, they change the color of the surface ocean from blue to green. Such shifts in ocean color can be measured from sensors placed high above the sea on satellites or aircraft and is called "ocean color remote sensing." In open ocean waters, the ocean color is predominantly driven by the phytoplankton concentration and ocean color remote sensing has been used to estimate the amount of chlorophyll a, the primary light-absorbing pigment in all phytoplankton. For the last few decades, satellite data have been used to estimate large-scale patterns of chlorophyll and to model primary productivity across the global ocean from daily to interannual timescales. Such global estimates of chlorophyll and primary productivity have been integrated into climate models and illustrate the important feedbacks between ocean life and global climate processes. In coastal and estuarine systems, ocean color is significantly influenced by other light-absorbing and light-scattering components besides phytoplankton. New approaches have been developed to evaluate the ocean color in relationship to colored dissolved organic matter, suspended sediments, and even to characterize the bathymetry and composition of the seafloor in optically shallow waters. Ocean color measurements are increasingly being used for environmental monitoring of harmful algal blooms, critical coastal habitats

A modeling experiment on the grounding of an ice shelf in the central Arctic Ocean during MIS 6

Science.gov (United States)

Jakobsson, M.; Siegert, M.; Paton, M.

2003-12-01

High-resolution chirp sonar subbottom profiles from the Lomonosov Ridge in the central Arctic Ocean, acquired from the Swedish icebreaker Oden in 1996, revealed large-scale erosion of the ridge crest down to depths of 1000 m below present sea level [Jakobsson, 1999]. Subsequent acoustic mapping during the SCICEX nuclear submarine expedition in 1999 showed glacial fluting at the deepest eroded areas and subparallel ice scours from 950 m water depth to the shallowest parts of the ridge crest [Polyak et al., 2001]. The directions of the mapped glaciogenic bed-forms and the redeposition of eroded material on the Amerasian side of the ridge indicate ice flow from the Barents-Kara Sea area. Core studies revealed that sediment drape the eroded areas from Marine Isotope Stage (MIS) 5.5 and, thus, it was proposed that the major erosional event took place during Marine Isotope Stage (MIS) 6 [Jakobsson et al., 2001]. Glacial geological evidence suggests strongly that the Late Saalian (MIS 6) ice sheet margin reached the shelf break of the Barents-Kara Sea [Svendsen et al. in press] and this gives us two possible ways to explain the ice erosional features on the Lomonosov Ridge. One is the grounding of a floating ice shelf and the other is the scouring from large deep tabular iceberg. Here we apply numerical ice sheet modeling to test the hypothesis that an ice shelf emanating from the Barents/Kara seas grounded across part of the Lomonsov Ridge and caused the extensive erosion down to a depth of around 1000 m below present sea level. A series of model experiments was undertaken in which the ice shelf mass balance (surface accumulation and basal melting) and ice shelf strain rates were adjusted. Grounding of the Lomonosov Ridge was not achieved when the ice shelf strain rate was 0.005 yr-1 (i.e. a free flowing ice shelf). However this model produced two interesting findings. First, with basal melt rates of up to 50 cm yr-1 an ice shelf grew from the St. Anna Trough ice stream

Deep Water Ocean Acoustics (DWOA): The Philippine Sea, OBSANP, and THAAW Experiments

Science.gov (United States)

2015-09-30

variability of the ambient noise field, and (v) understanding the relationship between the acoustic field in the water column and the seismic field in the...acoustic field in the water column and the seismic field in the seafloor for both ambient noise and signals transmitted by a J15-3 source and (2) the...frequent periods of low ambient noise.  Ice cover is still present throughout much of the year, insulating the ocean from wind and solar forcing and

Response of halocarbons to ocean acidification in the Arctic

NARCIS (Netherlands)

Hopkins, F.E.; Kimmance, S.A.; Stephens, J.A.; Bellerby, R.G.J.; Brussaard, C.P.D.; Czerny, J.; Schulz, K.G.; Archer, S.D.

2013-01-01

The potential effect of ocean acidification (OA) on seawater halocarbons in the Arctic was investigated during a mesocosm experiment in Spitsbergen in June-July 2010. Over a period of 5 weeks, natural phytoplankton communities in nine similar to 50 m(3) mesocosms were studied under a range of pCO(2)

Response of halocarbons to ocean acidification in the Arctic

NARCIS (Netherlands)

Hopkins, F.E.; Kimmance, S.A.; Stephens, J.A.; Bellerby, R.G.J.; Brussaard, C.P.D.; Czerny, J.; Schulz, K.G.; Archer, S.D.

2013-01-01

The potential effect of ocean acidification (OA) on seawater halocarbons in the Arctic was investigated during a mesocosm experiment in Spitsbergen in June-July 2010. Over a period of 5 weeks, natural phytoplankton communities in nine ~ 50 m3 mesocosms were studied under a range of pCO2 treatments

Adaptation of an unstructured-mesh, finite-element ocean model to the simulation of ocean circulation beneath ice shelves

Science.gov (United States)

Kimura, Satoshi; Candy, Adam S.; Holland, Paul R.; Piggott, Matthew D.; Jenkins, Adrian

2013-07-01

Several different classes of ocean model are capable of representing floating glacial ice shelves. We describe the incorporation of ice shelves into Fluidity-ICOM, a nonhydrostatic finite-element ocean model with the capacity to utilize meshes that are unstructured and adaptive in three dimensions. This geometric flexibility offers several advantages over previous approaches. The model represents melting and freezing on all ice-shelf surfaces including vertical faces, treats the ice shelf topography as continuous rather than stepped, and does not require any smoothing of the ice topography or any of the additional parameterisations of the ocean mixed layer used in isopycnal or z-coordinate models. The model can also represent a water column that decreases to zero thickness at the 'grounding line', where the floating ice shelf is joined to its tributary ice streams. The model is applied to idealised ice-shelf geometries in order to demonstrate these capabilities. In these simple experiments, arbitrarily coarsening the mesh outside the ice-shelf cavity has little effect on the ice-shelf melt rate, while the mesh resolution within the cavity is found to be highly influential. Smoothing the vertical ice front results in faster flow along the smoothed ice front, allowing greater exchange with the ocean than in simulations with a realistic ice front. A vanishing water-column thickness at the grounding line has little effect in the simulations studied. We also investigate the response of ice shelf basal melting to variations in deep water temperature in the presence of salt stratification.

Monitoring of ocean storage projects

Energy Technology Data Exchange (ETDEWEB)

Caldeira, K. [Energy and Environment Directorate, Lawrence Livermore National Laboratory, Livermore, CA (United States)

2003-02-01

It has been proposed that atmospheric CO2 accumulation could be slowed by capture of CO2 from point sources and subsequent storage of that CO2 in the ocean. If applied, such sequestration efforts would need to be monitored for compliance, effectiveness, and unintended consequences. Aboveground inspection and monitoring of facilities and practices, combined with ocean observations, could assure compliance with ocean sequestration guidelines and regulations. Ocean observations could be made using a variety of sensors mounted on moorings or underwater gliders. Long-term effectiveness and leakage to the atmosphere must be estimated from models, since on large spatial scales it will be impossible to observationally distinguish carbon stored by a project from variable concentrations of background carbon. Furthermore, the ocean naturally would absorb roughly 80% of fossil fuel CO2 released to the atmosphere within a millennium. This means that most of the CO2 sequestered in the ocean that leaks out to the atmosphere will be reabsorbed by the ocean. However, there is no observational way to distinguish remaining carbon from reabsorbed carbon. The science of monitoring unintended consequences in the deep ocean interior is at a primitive state. Little is understood about ecosystems of the deep ocean interior; and even less is understood about how those ecosystems would respond to added CO2. High priority research objectives should be (1) to improve our understanding of the natural ecosystems of the deep ocean, and (2) to improve our understanding of the response of these ecosystems to increased oceanic CO2 concentrations and decreased ocean pH.

Ocean energy

International Nuclear Information System (INIS)

2006-01-01

This annual evaluation is a synthesis of works published in 2006. Comparisons are presented between the wind power performances and European Commission White Paper and Biomass action plan objectives. The sector covers the energy exploitation of all energy flows specifically supplied by the seas and oceans. At present, most efforts in both research and development and in experimental implementation are concentrated on tidal currents and wave power. 90% of today worldwide ocean energy production is represented by a single site: the Rance Tidal Power Plant. Ocean energies must face up two challenges: progress has to be made in finalizing and perfecting technologies and costs must be brought under control. (A.L.B.)

Ocean acidification impacts bacteria-phytoplankton coupling at low-nutrient conditions

Science.gov (United States)

Hornick, Thomas; Bach, Lennart T.; Crawfurd, Katharine J.; Spilling, Kristian; Achterberg, Eric P.; Woodhouse, Jason N.; Schulz, Kai G.; Brussaard, Corina P. D.; Riebesell, Ulf; Grossart, Hans-Peter

2017-01-01

The oceans absorb about a quarter of the annually produced anthropogenic atmospheric carbon dioxide (CO2), resulting in a decrease in surface water pH, a process termed ocean acidification (OA). Surprisingly little is known about how OA affects the physiology of heterotrophic bacteria or the coupling of heterotrophic bacteria to phytoplankton when nutrients are limited. Previous experiments were, for the most part, undertaken during productive phases or following nutrient additions designed to stimulate algal blooms. Therefore, we performed an in situ large-volume mesocosm ( ˜ 55 m3) experiment in the Baltic Sea by simulating different fugacities of CO2 (fCO2) extending from present to future conditions. The study was conducted in July-August after the nominal spring bloom, in order to maintain low-nutrient conditions throughout the experiment. This resulted in phytoplankton communities dominated by small-sized functional groups (picophytoplankton). There was no consistent fCO2-induced effect on bacterial protein production (BPP), cell-specific BPP (csBPP) or biovolumes (BVs) of either free-living (FL) or particle-associated (PA) heterotrophic bacteria, when considered as individual components (univariate analyses). Permutational Multivariate Analysis of Variance (PERMANOVA) revealed a significant effect of the fCO2 treatment on entire assemblages of dissolved and particulate nutrients, metabolic parameters and the bacteria-phytoplankton community. However, distance-based linear modelling only identified fCO2 as a factor explaining the variability observed amongst the microbial community composition, but not for explaining variability within the metabolic parameters. This suggests that fCO2 impacts on microbial metabolic parameters occurred indirectly through varying physicochemical parameters and microbial species composition. Cluster analyses examining the co-occurrence of different functional groups of bacteria and phytoplankton further revealed a separation of

Methyl bromide: ocean sources, ocean sinks, and climate sensitivity.

Science.gov (United States)

Anbar, A D; Yung, Y L; Chavez, F P

1996-03-01

The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

Pelagic ecology of the South West Indian Ocean Ridge seamounts: Introduction and overview

Science.gov (United States)

Rogers, A. D.

2017-02-01

The Indian Ocean was described by Behrman (1981) as the "Forlorn Ocean", a region neglected by science up to the late-1950s. For example, the Challenger Expedition from 1872 to 1876 largely avoided the Indian Ocean, sailing from Cape Town into Antarctic waters sampling around the Prince Edward Islands, Kerguelen Island and Crozet Islands before heading to Melbourne. From 1876 to the 1950s there were expeditions on several vessels including the Valdivia, Gauss and Planet (Germany), the Snellius (Netherlands), Discovery II, MahaBiss (United Kingdom), Albatross (Sweden), Dana and Galathea (Denmark; Behrman, 1981). There was no coordination between these efforts and overall the Indian Ocean, especially the deep sea remained perhaps the most poorly explored of the world's oceans. This situation was largely behind the multilateral effort represented by the International Indian Ocean Expedition (IIEO), which was coordinated by the Scientific Committee for Ocean Research (SCOR), and which ran from 1959-1965. Work during this expedition focused on the Arabian Sea, the area to the northwest of Australia and the waters over the continental shelves and slopes of coastal states in the region. Subsequently several large-scale international oceanographic programmes have included significant components in the Indian Ocean, including the Joint Global Ocean Flux Study (JGOFS) and the World Ocean Circulation Experiment (WOCE). These studies were focused on physical oceanographic measurements and biogeochemistry and whilst the Indian Ocean is still less understood than other large oceans it is now integrated into the major ocean observation systems (Talley et al., 2011). This cannot be said for many aspects of the biology of the region, despite the fact that the Indian Ocean is one of the places where exploitation of marine living resources is still growing (FAO, 2016). The biology of the deep Indian Ocean outside of the Arabian Sea is particularly poorly understood given the presence

Proceedings of international workshop on utilization of nuclear power in oceans (N'ocean 2000)

International Nuclear Information System (INIS)

Yamaji, A.; Nariyama, N.; Sawada, K.

2000-03-01

Human beings and the ocean have maintained close relations for a long time. The ocean produced the life at very old time and human beings have been benefited by ocean, particularly in Japan that is surrounded by the ocean. In the utilization of nuclear power in ocean, Japan has been very active from the beginning of the development of nuclear power. The nuclear powered ship MUTSU has been developed and completed the experimental voyage. Besides the nuclear powered ship, we are using the ocean for the transportation of radioactive materials. This International Workshop aimed at offering further information about nuclear utilization in oceans such as icebreakers, deep-sea submarines, high speed carriers, floating plant, desalination and heating plants, radioactive materials transport ships, and so on. The discussions on the economical, environmental and scientific effects are included. The 36 of the present papers are indexed individually. (J.P.N.)

Ocean Uses: California

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This Ocean Uses Atlas Project is an innovative partnership between NOAA's National Marine Protected Areas Center and Marine Conservation Biology Institute. The...

Characterization of Prochlorococcus clades from iron-depleted oceanic regions.

Science.gov (United States)

Rusch, Douglas B; Martiny, Adam C; Dupont, Christopher L; Halpern, Aaron L; Venter, J Craig

2010-09-14

Prochlorococcus describes a diverse and abundant genus of marine photosynthetic microbes. It is primarily found in oligotrophic waters across the globe and plays a crucial role in energy and nutrient cycling in the ocean ecosystem. The abundance, global distribution, and availability of isolates make Prochlorococcus a model system for understanding marine microbial diversity and biogeochemical cycling. Analysis of 73 metagenomic samples from the Global Ocean Sampling expedition acquired in the Atlantic, Pacific, and Indian Oceans revealed the presence of two uncharacterized Prochlorococcus clades. A phylogenetic analysis using six different genetic markers places the clades close to known lineages adapted to high-light environments. The two uncharacterized clades consistently cooccur and dominate the surface waters of high-temperature, macronutrient-replete, and low-iron regions of the Eastern Equatorial Pacific upwelling and the tropical Indian Ocean. They are genetically distinct from each other and other high-light Prochlorococcus isolates and likely define a previously unrecognized ecotype. Our detailed genomic analysis indicates that these clades comprise organisms that are adapted to iron-depleted environments by reducing their iron quota through the loss of several iron-containing proteins that likely function as electron sinks in the photosynthetic pathway in other Prochlorococcus clades from high-light environments. The presence and inferred physiology of these clades may explain why Prochlorococcus populations from iron-depleted regions do not respond to iron fertilization experiments and further expand our understanding of how phytoplankton adapt to variations in nutrient availability in the ocean.

Our Changing Oceans: All about Ocean Acidification

International Nuclear Information System (INIS)

Rickwood, Peter

2013-01-01

The consequences of ocean acidification are global in scale. More research into ocean acidification and its consequences is needed. It is already known, for example, that there are regional differences in the vulnerability of fisheries to acidification. The combination of other factors, such as global warming, the destruction of habitats, overfishing and pollution, need to be taken into account when developing strategies to increase the marine environment’s resilience. Among steps that can be taken to reduce the impact is better protection of marine coastal ecosystems, such as mangrove swamps and seagrass meadows, which will help protect fisheries. This recommendation was one of the conclusions of a three-day workshop attended by economists and scientists and organized by the IAEA and the Centre Scientifique de Monaco in November 2012. In their recommendations the workshop also stressed that the impact of increasing ocean acidity must be taken into account in the management of fisheries, particularly where seafood is a main dietary source

Development of improved space sampling strategies for ocean chemical properties: Total carbon dioxide and dissolved nitrate

Science.gov (United States)

Goyet, Catherine; Davis, Daniel; Peltzer, Edward T.; Brewer, Peter G.

1995-01-01

Large-scale ocean observing programs such as the Joint Global Ocean Flux Study (JGOFS) and the World Ocean Circulation Experiment (WOCE) today, must face the problem of designing an adequate sampling strategy. For ocean chemical variables, the goals and observing technologies are quite different from ocean physical variables (temperature, salinity, pressure). We have recently acquired data on the ocean CO2 properties on WOCE cruises P16c and P17c that are sufficiently dense to test for sampling redundancy. We use linear and quadratic interpolation methods on the sampled field to investigate what is the minimum number of samples required to define the deep ocean total inorganic carbon (TCO2) field within the limits of experimental accuracy (+/- 4 micromol/kg). Within the limits of current measurements, these lines were oversampled in the deep ocean. Should the precision of the measurement be improved, then a denser sampling pattern may be desirable in the future. This approach rationalizes the efficient use of resources for field work and for estimating gridded (TCO2) fields needed to constrain geochemical models.

Ocean transport and variability studies of the South Pacific, Southern, and Indian Oceans

Science.gov (United States)

Church, John A.; Cresswell, G. R.; Nilsson, C. S.; Mcdougall, T. J.; Coleman, R.; Rizos, C.; Penrose, J.; Hunter, J. R.; Lynch, M. J.

1991-01-01

The objectives of this study are to analyze ocean dynamics in the western South Pacific and the adjacent Southern Ocean and the eastern Indian Ocean. Specifically, our objectives for these three regions are, for the South Pacific Ocean: (1) To estimate the volume transport of the east Australian Current (EAC) along the Australian coast and in the Tasman Front, and to estimate the time variability (on seasonal and interannual time scales) of this transport. (2) To contribute to estimating the meridional heat and freshwater fluxes (and their variability) at about 30 deg S. Good estimates of the transport in the western boundary current are essential for accurate estimates of these fluxes. (3) To determine how the EAC transport (and its extension, the Tasman Front and the East Auckland Current) closes the subtropical gyre of the South Pacific and to better determine the structure at the confluence of this current and the Antarctic Circumpolar Current. (4) To examine the structure and time variability of the circulation in the western South Pacific and the adjacent Southern Ocean, particularly at the Tasman Front. For the Indian Ocean: (5) To study the seasonal interannual variations in the strength of the Leeuwin Current. (6) To monitor the Pacific-Indian Ocean throughflow and the South Equatorial and the South Java Currents between northwest Australia and Indonesia. (7) To study the processes that form the water of the permanent oceanic thermocline and, in particular, the way in which new thermocline water enters the permanent thermocline in late winter and early spring as the mixed layer restratifies. For the Southern Ocean: (8) To study the mesoscale and meridional structure of the Southern Ocean between 150 deg E and 170 deg E; in particular, to describe the Antarctic frontal system south of Tasmania and determine its interannual variability; to estimate the exchanges of heat, salt, and other properties between the Indian and Pacific Oceans; and to investigate the

Validation and Inter-comparison Against Observations of GODAE Ocean View Ocean Prediction Systems

Science.gov (United States)

Xu, J.; Davidson, F. J. M.; Smith, G. C.; Lu, Y.; Hernandez, F.; Regnier, C.; Drevillon, M.; Ryan, A.; Martin, M.; Spindler, T. D.; Brassington, G. B.; Oke, P. R.

2016-02-01

For weather forecasts, validation of forecast performance is done at the end user level as well as by the meteorological forecast centers. In the development of Ocean Prediction Capacity, the same level of care for ocean forecast performance and validation is needed. Herein we present results from a validation against observations of 6 Global Ocean Forecast Systems under the GODAE OceanView International Collaboration Network. These systems include the Global Ocean Ice Forecast System (GIOPS) developed by the Government of Canada, two systems PSY3 and PSY4 from the French Mercator-Ocean Ocean Forecasting Group, the FOAM system from UK met office, HYCOM-RTOFS from NOAA/NCEP/NWA of USA, and the Australian Bluelink-OceanMAPS system from the CSIRO, the Australian Meteorological Bureau and the Australian Navy.The observation data used in the comparison are sea surface temperature, sub-surface temperature, sub-surface salinity, sea level anomaly, and sea ice total concentration data. Results of the inter-comparison demonstrate forecast performance limits, strengths and weaknesses of each of the six systems. This work establishes validation protocols and routines by which all new prediction systems developed under the CONCEPTS Collaborative Network will be benchmarked prior to approval for operations. This includes anticipated delivery of CONCEPTS regional prediction systems over the next two years including a pan Canadian 1/12th degree resolution ice ocean prediction system and limited area 1/36th degree resolution prediction systems. The validation approach of comparing forecasts to observations at the time and location of the observation is called Class 4 metrics. It has been adopted by major international ocean prediction centers, and will be recommended to JCOMM-WMO as routine validation approach for operational oceanography worldwide.

Ocean Station Vessel

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Ocean Station Vessels (OSV) or Weather Ships captured atmospheric conditions while being stationed continuously in a single location. While While most of the...

Topex/Poseidon: A United States/France mission. Oceanography from space: The oceans and climate

Science.gov (United States)

1992-01-01

The TOPEX/POSEIDON space mission, sponsored by NASA and France's space agency, the Centre National d'Etudes Spatiales (CNES), will give new observations of the Earth from space to gain a quantitative understanding of the role of ocean currents in climate change. Rising atmospheric concentrations of carbon dioxide and other 'greenhouse gases' produced as a result of human activities could generate a global warming, followed by an associated rise in sea level. The satellite will use radar altimetry to measure sea-surface height and will be tracked by three independent systems to yield accurate topographic maps over the dimensions of entire ocean basins. The satellite data, together with the Tropical Ocean and Global Atmosphere (TOGA) program and the World Ocean Circulation Experiment (WOCE) measurements, will be analyzed by an international scientific team. By merging the satellite observations with TOGA and WOCE findings, the scientists will establish the extensive data base needed for the quantitative description and computer modeling of ocean circulation. The ocean models will eventually be coupled with atmospheric models to lay the foundation for predictions of global climate change.

Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms.

Science.gov (United States)

Orr, James C; Fabry, Victoria J; Aumont, Olivier; Bopp, Laurent; Doney, Scott C; Feely, Richard A; Gnanadesikan, Anand; Gruber, Nicolas; Ishida, Akio; Joos, Fortunat; Key, Robert M; Lindsay, Keith; Maier-Reimer, Ernst; Matear, Richard; Monfray, Patrick; Mouchet, Anne; Najjar, Raymond G; Plattner, Gian-Kasper; Rodgers, Keith B; Sabine, Christopher L; Sarmiento, Jorge L; Schlitzer, Reiner; Slater, Richard D; Totterdell, Ian J; Weirig, Marie-France; Yamanaka, Yasuhiro; Yool, Andrew

2005-09-29

Today's surface ocean is saturated with respect to calcium carbonate, but increasing atmospheric carbon dioxide concentrations are reducing ocean pH and carbonate ion concentrations, and thus the level of calcium carbonate saturation. Experimental evidence suggests that if these trends continue, key marine organisms--such as corals and some plankton--will have difficulty maintaining their external calcium carbonate skeletons. Here we use 13 models of the ocean-carbon cycle to assess calcium carbonate saturation under the IS92a 'business-as-usual' scenario for future emissions of anthropogenic carbon dioxide. In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously.

Low helium flux from the mantle inferred from simulations of oceanic helium isotope data

Science.gov (United States)

Bianchi, Daniele; Sarmiento, Jorge L.; Gnanadesikan, Anand; Key, Robert M.; Schlosser, Peter; Newton, Robert

2010-09-01

The high 3He/ 4He isotopic ratio of oceanic helium relative to the atmosphere has long been recognized as the signature of mantle 3He outgassing from the Earth's interior. The outgassing flux of helium is frequently used to normalize estimates of chemical fluxes of elements from the solid Earth, and provides a strong constraint to models of mantle degassing. Here we use a suite of ocean general circulation models and helium isotope data obtained by the World Ocean Circulation Experiment to constrain the flux of helium from the mantle to the oceans. Our results suggest that the currently accepted flux is overestimated by a factor of 2. We show that a flux of 527 ± 102 mol year - 1 is required for ocean general circulation models that produce distributions of ocean ventilation tracers such as radiocarbon and chlorofluorocarbons that match observations. This new estimate calls for a reevaluation of the degassing fluxes of elements that are currently tied to the helium fluxes, including noble gases and carbon dioxide.

Winter snow conditions on Arctic sea ice north of Svalbard during the Norwegian young sea ICE (N-ICE2015) expedition

Science.gov (United States)

Merkouriadi, Ioanna; Gallet, Jean-Charles; Graham, Robert M.; Liston, Glen E.; Polashenski, Chris; Rösel, Anja; Gerland, Sebastian

2017-10-01

Snow is a crucial component of the Arctic sea ice system. Its thickness and thermal properties control heat conduction and radiative fluxes across the ocean, ice, and atmosphere interfaces. Hence, observations of the evolution of snow depth, density, thermal conductivity, and stratigraphy are crucial for the development of detailed snow numerical models predicting energy transfer through the snow pack. Snow depth is also a major uncertainty in predicting ice thickness using remote sensing algorithms. Here we examine the winter spatial and temporal evolution of snow physical properties on first-year (FYI) and second-year ice (SYI) in the Atlantic sector of the Arctic Ocean, during the Norwegian young sea ICE (N-ICE2015) expedition (January to March 2015). During N-ICE2015, the snow pack consisted of faceted grains (47%), depth hoar (28%), and wind slab (13%), indicating very different snow stratigraphy compared to what was observed in the Pacific sector of the Arctic Ocean during the SHEBA campaign (1997-1998). Average snow bulk density was 345 kg m-3 and it varied with ice type. Snow depth was 41 ± 19 cm in January and 56 ± 17 cm in February, which is significantly greater than earlier suggestions for this region. The snow water equivalent was 14.5 ± 5.3 cm over first-year ice and 19 ± 5.4 cm over second-year ice.

Testing Predictions of Continental Insulation using Oceanic Crustal Thicknesses

Science.gov (United States)

Hoggard, Mark; Shorttle, Oliver; White, Nicky

2016-04-01

The thermal blanketing effect of continental crust has been predicted to lead to elevated temperatures within the upper mantle beneath supercontinents. Initial break-up is associated with increased magmatism and the generation of flood basalts. Continued rifting and sea-floor spreading lead to a steady reduction of this thermal anomaly. Recently, evidence in support of this behaviour has come from the major element geochemistry of mid-ocean ridge basalts, which suggest excess rifting temperatures of ˜ 150 °C that decay over ˜ 100 Ma. We have collated a global inventory of ˜ 1000 seismic reflection profiles and ˜ 500 wide-angle refraction experiments from the oceanic realm. Data are predominantly located along passive margins, but there are also multiple surveys in the centres of the major oceanic basins. Oceanic crustal thickness has been mapped, taking care to avoid areas of secondary magmatic thickening near seamounts or later thinning such as across transform faults. These crustal thicknesses are a proxy for mantle potential temperature at the time of melt formation beneath a mid-ocean ridge system, allowing us to quantify the amplitude and duration of thermal anomalies generated beneath supercontinents. The Jurassic break-up of the Central Atlantic and the Cretaceous rifting that formed the South Atlantic Ocean are both associated with excess temperatures of ˜ 50 °C that have e-folding times of ˜ 50 Ma. In addition to this background trend, excess temperatures reach > 150 °C around the region of the Rio Grande Rise, associated with the present-day Tristan hotspot. The e-folding time of this more local event is ˜ 10 Ma, which mirrors results obtained for the North Atlantic Ocean south of Iceland. In contrast, crustal thicknesses from the Pacific Ocean reveal approximately constant potential temperature through time. This observation is in agreement with predictions, as the western Pacific was formed by rifting of an oceanic plate. In summary

Ocean Physicochemistry versus Climate Change

OpenAIRE

Góralski, Bogdan

2014-01-01

It is the dwindling ocean productivity which leaves dissolved carbon dioxide in the seawater. Its solubility is diminished by the rise in ocean water temperature (by one degree Celsius since 1910, according to IPCC). Excess carbon dioxide is emitted into the atmosphere, while its growing concentration in seawater leads to ocean acidification. Ocean acidification leading to lowering pH of surface ocean water remains an unsolved problem of science. My today’s lecture will mark an attempt at ...

The Oceans 2015 Initiative, Part I - An updated synthesis of the observed and projected impacts of climate change on physical and biological processes in the oceans

International Nuclear Information System (INIS)

Howes, Ella L.; Joos, Fortunat; Eakin, Mark; Gattuso, Jean-Pierre

2015-01-01

The oceans have absorbed approximately 93% of the excess heat caused by global warming. Warming increases stratification, limiting the circulation of nutrients from deep waters to the surface. There is evidence that enhanced stratification and increasing temperature are causing a decline in dissolved oxygen concentration and expanding existing oxygen minimum zones (OMZs). Approximately 26% of anthropogenic CO 2 is absorbed by the oceans, resulting in a reduction in pH and carbonate ion concentration, termed ocean acidification. Anthropogenic CO 2 has caused global ocean pH to decrease by 0.1 units since the start of the Industrial Revolution. The ocean ecosystems are responding to the changing environment, but at different rates and magnitudes and with interspecific and geographic variation in responses. Warming causes shifts in species' geographic distribution, abundance, migration patterns and phenology. Organisms that produce shells and skeletons from calcium carbonate are at most risk from ocean acidification as it lowers the saturation state of the mineral, favouring a dissolution reaction. To date, there are few observations of ocean acidification effects in natural communities; however, experimental evidence suggests that the risk to ecosystems will increase over the coming decades. Decreasing dissolved oxygen concentrations and expanding OMZs will favour anaerobic metabolisers such as bacteria and small microbes whilst reducing habitat for larger, oxygen dependent organisms. The interaction of multiple drivers can amplify or alleviate each other's effects. It is likely that marine organisms will experience a combination of warming, acidification and declining oxygen concentrations as well as regionally specific local stressors. This makes it difficult to predict the responses of individual species to multiple drivers, and species interactions make ecosystem- based projections challenging. Using the available evidence, projections have been

People and Oceans.

Science.gov (United States)

NatureScope, 1988

1988-01-01

Discusses people's relationship with oceans, focusing on ocean pollution, use, and protective measures of the sea and its wildlife. Activities included are "Mythical Monsters"; "Globetrotters"; "Plastic in the Sea"; and "Sea of Many Uses." (RT)

Ocean Disposal Sites

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In 1972, Congress enacted the Marine Protection, Research, and Sanctuaries Act (MPRSA, also known as the Ocean Dumping Act) to prohibit the dumping of material into...

Canada Basin Acoustic Propagation Experiment (CANAPE)

Science.gov (United States)

2015-09-30

acoustic communications, acoustic navigation, or acoustic remote sensing of the ocean interior . RELATED PROJECTS The 2015 CANAPE pilot study was a...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Canada Basin Acoustic Propagation Experiment (CANAPE...ocean structure. Changes in sea ice and the water column affect both acoustic propagation and ambient noise. This implies that what was learned

Detecting the progression of ocean acidification from the saturation state of CaCO3 in the subtropical South Pacific

Science.gov (United States)

Murata, Akihiko; Hayashi, Kazuhiko; Kumamoto, Yuichiro; Sasaki, Ken-ichi

2015-04-01

Progression of ocean acidification in the subtropical South Pacific was investigated by using high-quality data from trans-Pacific zonal section at 17°S (World Ocean Circulation Experiment section P21) collected in 1994 and 2009. During this 15 year period, the CaCO3 saturation state of seawater with respect to calcite (Ωcal) and aragonite (Ωarg) in the upper water column (Pacific Ocean.

AFSC/RACE/SAP/Foy: The effects of ocean acidification on ovigerous Tanner crab size, calcium, and magnesium content. : Kodiak Island, Alaska.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — To study the effects of ocean acidification we conducted laboratory experiments with adult ovigerous females of the economically important southern Tanner crab,...

Sharing Data in the Global Ocean Observing System (Invited)

Science.gov (United States)

Lindstrom, E. J.; McCurdy, A.; Young, J.; Fischer, A. S.

2010-12-01

We examine the evolution of data sharing in the field of physical oceanography to highlight the challenges now before us. Synoptic global observation of the ocean from space and in situ platforms has significantly matured over the last two decades. In the early 1990’s the community data sharing challenges facing the World Ocean Circulation Experiment (WOCE) largely focused on the behavior of individual scientists. Satellite data sharing depended on the policy of individual agencies. Global data sets were delivered with considerable delay and with enormous personal sacrifice. In the 2000’s the requirements for global data sets and sustained observations from the likes of the U.N. Framework Convention on Climate Change have led to data sharing and cooperation at a grander level. It is more effective and certainly more efficient. The Joint WMO/IOC Technical Commission on Oceanography and Marine Meteorology (JCOMM) provided the means to organize many aspects of data collection and data dissemination globally, for the common good. In response the Committee on Earth Observing Satellites organized Virtual Constellations to enable the assembly and sharing of like kinds of satellite data (e.g., sea surface topography, ocean vector winds, and ocean color). Individuals in physical oceanography have largely adapted to the new rigors of sharing data for the common good, and as a result of this revolution new science has been enabled. Primary obstacles to sharing have shifted from the individual level to the national level. As we enter into the 2010’s the demands for ocean data continue to evolve with an expanded requirement for more real-time reporting and broader disciplinary coverage, to answer key scientific and societal questions. We are also seeing the development of more numerous national contributions to the global observing system. The drivers for the establishment of global ocean observing systems are expanding beyond climate to include biological and

Drift in ocean currents impacts intergenerational microbial exposure to temperature.

Science.gov (United States)

Doblin, Martina A; van Sebille, Erik

2016-05-17

Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034-1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming.

Use of a free ocean CO₂ enrichment (FOCE) system to evaluate the effects of ocean acidification on the foraging behavior of a deep-sea urchin.

Science.gov (United States)

Barry, James P; Lovera, Chris; Buck, Kurt R; Peltzer, Edward T; Taylor, Josi R; Walz, Peter; Whaling, Patrick J; Brewer, Peter G

2014-08-19

The influence of ocean acidification in deep-sea ecosystems is poorly understood but is expected to be large because of the presumed low tolerance of deep-sea taxa to environmental change. We used a newly developed deep-sea free ocean CO2 enrichment (dp-FOCE) system to evaluate the potential consequences of future ocean acidification on the feeding behavior of a deep-sea echinoid, the sea urchin, Strongylocentrotus fragilis. The dp-FOCE system simulated future ocean acidification inside an experimental enclosure where observations of feeding behavior were performed. We measured the average movement (speed) of urchins as well as the time required (foraging time) for S. fragilis to approach its preferred food (giant kelp) in the dp-FOCE chamber (-0.46 pH units) and a control chamber (ambient pH). Measurements were performed during each of 4 trials (days -2, 2, 24, 27 after CO2 injection) during the month-long period when groups of urchins were continuously exposed to low pH or control conditions. Although urchin speed did not vary significantly in relation to pH or time exposed, foraging time was significantly longer for urchins in the low-pH treatment. This first deep-sea FOCE experiment demonstrated the utility of the FOCE system approach and suggests that the chemosensory behavior of a deep-sea urchin may be impaired by ocean acidification.

Vital Signs: Seismology of Icy Ocean Worlds.

Science.gov (United States)

Vance, Steven D; Kedar, Sharon; Panning, Mark P; Stähler, Simon C; Bills, Bruce G; Lorenz, Ralph D; Huang, Hsin-Hua; Pike, W T; Castillo, Julie C; Lognonné, Philippe; Tsai, Victor C; Rhoden, Alyssa R

2018-01-01

Ice-covered ocean worlds possess diverse energy sources and associated mechanisms that are capable of driving significant seismic activity, but to date no measurements of their seismic activity have been obtained. Such investigations could reveal the transport properties and radial structures, with possibilities for locating and characterizing trapped liquids that may host life and yielding critical constraints on redox fluxes and thus on habitability. Modeling efforts have examined seismic sources from tectonic fracturing and impacts. Here, we describe other possible seismic sources, their associations with science questions constraining habitability, and the feasibility of implementing such investigations. We argue, by analogy with the Moon, that detectable seismic activity should occur frequently on tidally flexed ocean worlds. Their ices fracture more easily than rocks and dissipate more tidal energy than the worlds also should create less thermal noise due to their greater distance and consequently smaller diurnal temperature variations. They also lack substantial atmospheres (except in the case of Titan) that would create additional noise. Thus, seismic experiments could be less complex and less susceptible to noise than prior or planned planetary seismology investigations of the Moon or Mars. Key Words: Seismology-Redox-Ocean worlds-Europa-Ice-Hydrothermal. Astrobiology 18, 37-53.

Impact of effective ocean optical properties on the Pacific subtropical cell: a CGCM study

Science.gov (United States)

Yamanaka, G.; Tsujino, H.; Ishizaki, H.; Nakano, H.; Hirabara, M.

2012-12-01

The choice of ocean radiant scheme is important for modeling the upper ocean. According to the ocean-only simulation (Yamanaka et al., 2012), introduction of the chlorophyll-a dependent ocean radiant scheme results in the decreased mixed layer depth (MLD), the enhanced subtropical cell (STC), and the cooling of the eastern tropical Pacific sea surface temperature (SST). They also found that the enhanced STC results from the velocity profile change associated with the decreased Ekman boundary layer. However, the impact is not well understood when the air-sea feedback process is at work. This study examines the impact of the effective ocean optical properties on the Pacific mean fields, especially focusing on the STC, using a coupled general circulation model (CGCM). The CGCM we employed is the Meteorological Research Institute Earth System Model (MRI-ESM1). The atmospheric model is TL159L48, and the ocean model has a horizontal resolution of 1 x 0.5 deg. with 51 levels in vertical. Experimental design basically follows the CMIP5 protocol. Two experiments (CTL and SLR runs) are performed to investigate the impact of the effective ocean optical properties. In the CTL run, a conventional ocean radiant heating scheme (Paul and Simpson, 1977) is used, whereas a new ocean radiant heating scheme is used in the SLR run, where the satellite-derived chlorophyll-a distribution is taken into consideration based on Morel and Antoine (1994) as well as the effect of the varying solar angle (Ishizaki and Yamanaka, 2010). Each experiment is integrated during the period from 1985 to 2005. It is found that introduction of the new ocean radiant scheme (SLR run) changes the long-term mean wind pattern in the Pacific: easterly winds are strengthened in the equatorial Pacific, but weakened in the off-equatorial region. In the tropical Pacific, the enhanced equatorial upwelling cools the equatorial SST and the MLD becomes shallower. This is similar to the ocean-only simulation, but is more

The mechanism of upper-oceanic vertical motions forced by a moving typhoon

International Nuclear Information System (INIS)

Suzuki, Shin-ichi; Niino, Hiroshi; Kimura, Ryuji

2011-01-01

The upper-oceanic response to a moving typhoon, and the mechanism of the response, are studied based on linear theory and a numerical experiment. The results of the analysis by linear theory are summarized as follows. Three different processes (Ekman pumping, inertial pumping and 'anti-Ekman' pumping) contribute to the upper-oceanic vertical motions caused by a moving atmospheric disturbance. The dominant process depends on the Coriolis parameter f, the moving speed U of the disturbance and the along-track wavenumber spectrum of the wind stress curl. In the case of a typhoon, when the wavenumber spectrum has a dominant amplitude at k< f/U, Ekman pumping is the dominant mechanism and upwelling occurs at the typhoon center, where k is the along-track wavenumber. When the wavenumber spectrum has a significant amplitude near k∼f/U, inertial pumping is dominant and upwelling occurs to the rear of the typhoon center. The results of the numerical experiments show that linear theory performs well in explaining the horizontal structures of the upper-oceanic vertical motions and their dependence on the moving speed of the typhoon.

The Role of Mid-Atlantic Ocean Data Portal in Supporting Ocean Planning

Directory of Open Access Journals (Sweden)

Richard G. Lathrop

2017-08-01

Full Text Available The Mid-Atlantic Regional Council on the Ocean (MARCO was established in 2009 to enhance the vitality of the region's ocean ecosystem and economy. One of MARCO's first action items was the development of the Mid-Atlantic Ocean Data Portal to serve as an on-line platform to engage stakeholders across the region with the objective of improving their understanding of how ocean resources and places are being used, managed, and conserved. A key component is the Marine Planner, an interactive map-based visualization and decision support tool. These types of on-line tools are becoming increasingly popular means of putting essential data and state-of-the-art visualization technology into the hands of the agencies, industry, community leaders, and stakeholders engaged in ocean planning. However, to be effective, the underlying geospatial data has to be seen as objective, comprehensive, up-to-date and regionally consistent. To meet this challenge, the portal utilizes a distributed network of web map services from credible and authoritative sources. Website analytics and feedback received during the review and comment period of the 2016 release of the Mid-Atlantic Ocean Action Plan confirm that the Data Portal is viewed as integral to this ocean planning process by the MidAtlantic Regional Planning Body and key stakeholders. While not all stakeholders may agree with specific planning decisions, there is broad based agreement on the need for better data and making access to that data widely available.

Ocean heat content variability and change in an ensemble of ocean reanalyses

Science.gov (United States)

Palmer, M. D.; Roberts, C. D.; Balmaseda, M.; Chang, Y.-S.; Chepurin, G.; Ferry, N.; Fujii, Y.; Good, S. A.; Guinehut, S.; Haines, K.; Hernandez, F.; Köhl, A.; Lee, T.; Martin, M. J.; Masina, S.; Masuda, S.; Peterson, K. A.; Storto, A.; Toyoda, T.; Valdivieso, M.; Vernieres, G.; Wang, O.; Xue, Y.

2017-08-01

Accurate knowledge of the location and magnitude of ocean heat content (OHC) variability and change is essential for understanding the processes that govern decadal variations in surface temperature, quantifying changes in the planetary energy budget, and developing constraints on the transient climate response to external forcings. We present an overview of the temporal and spatial characteristics of OHC variability and change as represented by an ensemble of dynamical and statistical ocean reanalyses (ORAs). Spatial maps of the 0-300 m layer show large regions of the Pacific and Indian Oceans where the interannual variability of the ensemble mean exceeds ensemble spread, indicating that OHC variations are well-constrained by the available observations over the period 1993-2009. At deeper levels, the ORAs are less well-constrained by observations with the largest differences across the ensemble mostly associated with areas of high eddy kinetic energy, such as the Southern Ocean and boundary current regions. Spatial patterns of OHC change for the period 1997-2009 show good agreement in the upper 300 m and are characterized by a strong dipole pattern in the Pacific Ocean. There is less agreement in the patterns of change at deeper levels, potentially linked to differences in the representation of ocean dynamics, such as water mass formation processes. However, the Atlantic and Southern Oceans are regions in which many ORAs show widespread warming below 700 m over the period 1997-2009. Annual time series of global and hemispheric OHC change for 0-700 m show the largest spread for the data sparse Southern Hemisphere and a number of ORAs seem to be subject to large initialization `shock' over the first few years. In agreement with previous studies, a number of ORAs exhibit enhanced ocean heat uptake below 300 and 700 m during the mid-1990s or early 2000s. The ORA ensemble mean (±1 standard deviation) of rolling 5-year trends in full-depth OHC shows a relatively steady

Survey on utility technology of a tidal and ocean current energy

Science.gov (United States)

Hirose, Manabu; Kadoyu, Masataka; Tanaka, Hiroyoshi

1987-06-01

A study is made to show the current technological levels in Japan and other nations regarding the conversion of tidal current or ocean current energy to electric power and to determine the latent energy quantities and energy-related characteristics of tidal and ocean currents. In Japan, relatively large-scale experiments made so far mostly used one of the following three types of devices: Savonius-wheel type, Darrieus-wheel type, and cross-flow-wheel type. Field experiments of tidal energy conversion have been performed at the Naruto and Kurushima Straits. The energy in the Kuroshio current is estimated at about 170 billion kWh per year. Ocean current energy does not undergo large seasonal variations. The total energy in major straits and channels in the Inland Sea and other sea areas to the west is estimated at about 124 billion kWh per year. Tidal current energy shows large seasonal variations, but it is possible to predict the changes. A survey is made to determine energy-related characteristics of a tidal current at Chichino-seto, Kagoshima Prefecture. At Chichino-seto, the flow velocity ranges from 0 to 2.2m/s, with a latent tidal current energy of about 70 kW, of which about 20 kW can actually be utilized.

Southern Ocean Phytoplankton in a Changing Climate

OpenAIRE

Deppeler, Stacy L.; Davidson, Andrew T.

2017-01-01

Phytoplankton are the base of the Antarctic food web, sustain the wealth and diversity of life for which Antarctica is renowned, and play a critical role in biogeochemical cycles that mediate global climate. Over the vast expanse of the Southern Ocean (SO), the climate is variously predicted to experience increased warming, strengthening wind, acidification, shallowing mixed layer depths, increased light (and UV), changes in upwelling and nutrient replenishment, declining sea ice, reduced sal...

Ocean energies

International Nuclear Information System (INIS)

Charlier, R.H.; Justus, J.R.

1993-01-01

This timely volume provides a comprehensive review of current technology for all ocean energies. It opens with an analysis of ocean thermal energy conversion (OTEC), with and without the use of an intermediate fluid. The historical and economic background is reviewed, and the geographical areas in which this energy could be utilized are pinpointed. The production of hydrogen as a side product, and environmental consequences of OTEC plants are considered. The competitiveness of OTEC with conventional sources of energy is analysed. Optimisation, current research and development potential are also examined. Separate chapters provide a detailed examination of other ocean energy sources. The possible harnessing of solar ponds, ocean currents, and power derived from salinity differences is considered. There is a fascinating study of marine winds, and the question of using the ocean tides as a source of energy is examined, focussing on a number of tidal power plant projects, including data gathered from China, Australia, Great Britain, Korea and the USSR. Wave energy extraction has excited recent interest and activity, with a number of experimental pilot plants being built in northern Europe. This topic is discussed at length in view of its greater chance of implementation. Finally, geothermal and biomass energy are considered, and an assessment of their future is given. The authors also distinguished between energy schemes which might be valuable in less-industrialized regions of the world, but uneconomical in the developed countries. A large number of illustrations support the text. This book will be of particular interest to energy economists, engineers, geologists and oceanographers, and to environmentalists and environmental engineers

Ocean Acidification from space: recent advances

Science.gov (United States)

Sabia, Roberto; Shutler, Jamie; Land, Peter; Fernandez-Prieto, Diego; Donlon, Craig; Reul, Nicolas

2017-04-01

The phenomenon referred to as Ocean Acidification (OA) is gathering increasing attention as one of the major foci of climate-related research, for its profound impact at scientific and socio-economic level. To date, the majority of the scientific studies into the potential impacts of OA have focused on in-situ measurements, laboratory-controlled experiments and models simulations. Satellite remote sensing technology have yet to be fully exploited, despite it has been stressed it could play a significant role by providing synoptic and frequent measurements for investigating globally OA processes, also extending in-situ carbonate chemistry measurements on different spatial/temporal scales [1,2]. Within this context, the purpose of the recently completed ESA "Pathfinders - Ocean Acidification" project was to quantitatively and routinely estimate OA-related parameters by means of a blending of satellite observations and model outputs in five case-study regions (global ocean, Amazon plume, Barents sea, Greater Caribbean and Bay of Bengal). Satellite Ocean Colour, Sea Surface Temperature (SST) and Sea Surface Salinity (SSS) have been exploited, with an emphasis on the latter being the latest addition to the portfolio of satellite measured parameters. A proper merging of these different satellites products allows computing at least two independent proxies among the seawater carbonate system parameters: the partial pressure of CO2 in surface seawater (pCO2); the total Dissolved Inorganic Carbon (DIC), the total alkalinity (TA) and the surface ocean pH. In the project, efforts have been devoted to a systematic characterization of TA and DIC from space in the mentioned case-study regions; in this paper, also through the knowledge of these parameters, the objective is to come up with the currently best educated guess of the surface ocean pH [3] and Aragonite saturation state. This will also include an estimation of the achievable accuracy by propagating the errors in the

The dependence of the oceans MOC on mesoscale eddy diffusivities: A model study

Science.gov (United States)

Marshall, John; Scott, Jeffery R.; Romanou, Anastasia; Kelley, Maxwell; Leboissetier, Anthony

2017-01-01

The dependence of the depth and strength of the ocean's global meridional overturning cells (MOC) on the specification of mesoscale eddy diffusivity (K) is explored in two ocean models. The GISS and MIT ocean models are driven by the same prescribed forcing fields, configured in similar ways, spun up to equilibrium for a range of K 's and the resulting MOCs mapped and documented. Scaling laws implicit in modern theories of the MOC are used to rationalize the results. In all calculations the K used in the computation of eddy-induced circulation and that used in the representation of eddy stirring along neutral surfaces, is set to the same value but is changed across experiments. We are able to connect changes in the strength and depth of the Atlantic MOC, the southern ocean upwelling MOC, and the deep cell emanating from Antarctica, to changes in K.

What can Citizen Science do for Ocean Science and Ocean Scientists?

Science.gov (United States)

Best, M.; Hoeberechts, M.; Mangin, A.; Oggioni, A.; Orcutt, J. A.; Parrish, J.; Pearlman, J.; Piera, J.; Tagliolato, P.

2016-12-01

The ocean represents over 70% of our planet's surface area, over 90% of the living space. Humans are not marine creatures, we therefore have fundamentally not built up knowledge of the ocean in the same way we have on land. The more we learn about the ocean, the more we understand it is the regulatory engine of our planet…How do we catch up? Answers to this question will need to come from many quarters; A powerful and strategic option to complement existing observation programs and infrastructure is Citizen Science. There has been significant and relevant discussion of the importance of Citizen Science to citizens and stakeholders. The missing effective question is sometimes what is the potential of citizen science for scientists? The answers for both scientists and society are: spatial coverage, remote locations, temporal coverage, event response, early detection of harmful processes, sufficient data volume for statistical analysis and identification of outliers, integrating local knowledge, data access in exchange for analysis (e.g. with industry) and cost-effective monitoring systems. Citizens can be involved in: instrument manufacture and maintenance, instrument deployment/sample collection, data collection and transmission, data analysis, data validation/verification, and proposals of new topics of research. Such opportunities are balanced by concern on the part of scientists about the quality, the consistency and the reliability of citizen observations and analyses. Experience working with citizen science groups continues to suggest that with proper training and mentoring, these issues can be addressed, understanding both benefits and limitations. How to do it- implementation and maintenance of citizen science: How to recruit, engage, train, and maintain Citizen Scientists. Data systems for acquisition, assessment, access, analysis, and visualisation of distributed data sources. Tools/methods for acquiring observations: Simple instruments, Smartphone Apps

The effect of ocean acidification and prey availabity on the growth of larval northern rock sole (Lepidopsetta polyxystra) (NCEI Accession 0157081)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment results of the effect of ocean acidification (OA) and prey availability on the growth of larval northern rock...

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean

International Nuclear Information System (INIS)

Eden, H.F.; Mooers, C.N.K.

1990-06-01

The goal of COPS is to couple a program of regular observations to numerical models, through techniques of data assimilation, in order to provide a predictive capability for the US coastal ocean including the Great Lakes, estuaries, and the entire Exclusive Economic Zone (EEZ). The objectives of the program include: determining the predictability of the coastal ocean and the processes that govern the predictability; developing efficient prediction systems for the coastal ocean based on the assimilation of real-time observations into numerical models; and coupling the predictive systems for the physical behavior of the coastal ocean to predictive systems for biological, chemical, and geological processes to achieve an interdisciplinary capability. COPS will provide the basis for effective monitoring and prediction of coastal ocean conditions by optimizing the use of increased scientific understanding, improved observations, advanced computer models, and computer graphics to make the best possible estimates of sea level, currents, temperatures, salinities, and other properties of entire coastal regions

Temperature Data Assimilation with Salinity Corrections: Validation for the NSIPP Ocean Data Assimilation System in the Tropical Pacific Ocean, 1993-1998

Science.gov (United States)

Troccoli, Alberto; Rienecker, Michele M.; Keppenne, Christian L.; Johnson, Gregory C.

2003-01-01

The NASA Seasonal-to-Interannual Prediction Project (NSIPP) has developed an Ocean data assimilation system to initialize the quasi-isopycnal ocean model used in our experimental coupled-model forecast system. Initial tests of the system have focused on the assimilation of temperature profiles in an optimal interpolation framework. It is now recognized that correction of temperature only often introduces spurious water masses. The resulting density distribution can be statically unstable and also have a detrimental impact on the velocity distribution. Several simple schemes have been developed to try to correct these deficiencies. Here the salinity field is corrected by using a scheme which assumes that the temperature-salinity relationship of the model background is preserved during the assimilation. The scheme was first introduced for a zlevel model by Troccoli and Haines (1999). A large set of subsurface observations of salinity and temperature is used to cross-validate two data assimilation experiments run for the 6-year period 1993-1998. In these two experiments only subsurface temperature observations are used, but in one case the salinity field is also updated whenever temperature observations are available.

From laboratory manipulations to Earth system models: scaling calcification impacts of ocean acidification

Directory of Open Access Journals (Sweden)

J. R. Young

2009-11-01

Full Text Available The observed variation in the calcification responses of coccolithophores to changes in carbonate chemistry paints a highly incoherent picture, particularly for the most commonly cultured "species", Emiliania huxleyi. The disparity between magnitude and potentially even sign of the calcification change under simulated end-of-century ocean surface chemical changes (higher pCO₂, lower pH and carbonate saturation, raises challenges to quantifying future carbon cycle impacts and feedbacks because it introduces significant uncertainty in parameterizations used for global models. Here we compile the results of coccolithophore carbonate chemistry manipulation experiments and review how ocean carbon cycle models have attempted to bridge the gap from experiments to global impacts. Although we can rule out methodological differences in how carbonate chemistry is altered as introducing an experimental bias, the absence of a consistent calcification response implies that model parameterizations based on small and differing subsets of experimental observations will lead to varying estimates for the global carbon cycle impacts of ocean acidification. We highlight two pertinent observations that might help: (1 the degree of coccolith calcification varies substantially, both between species and within species across different genotypes, and (2 the calcification response across mesocosm and shipboard incubations has so-far been found to be relatively consistent. By analogy to descriptions of plankton growth rate vs. temperature, such as the "Eppley curve", which seek to encapsulate the net community response via progressive assemblage change rather than the response of any single species, we posit that progressive future ocean acidification may drive a transition in dominance from more to less heavily calcified coccolithophores. Assemblage shift may be more important to integrated community calcification response than species

FEASIBILITY OF LARGE-SCALE OCEAN CO2 SEQUESTRATION

Energy Technology Data Exchange (ETDEWEB)

Dr. Peter Brewer; Dr. James Barry

2002-09-30

We have continued to carry out creative small-scale experiments in the deep ocean to investigate the science underlying questions of possible future large-scale deep-ocean CO{sub 2} sequestration as a means of ameliorating greenhouse gas growth rates in the atmosphere. This project is closely linked to additional research funded by the DoE Office of Science, and to support from the Monterey Bay Aquarium Research Institute. The listing of project achievements here over the past year reflects these combined resources. Within the last project year we have: (1) Published a significant workshop report (58 pages) entitled ''Direct Ocean Sequestration Expert's Workshop'', based upon a meeting held at MBARI in 2001. The report is available both in hard copy, and on the NETL web site. (2) Carried out three major, deep ocean, (3600m) cruises to examine the physical chemistry, and biological consequences, of several liter quantities released on the ocean floor. (3) Carried out two successful short cruises in collaboration with Dr. Izuo Aya and colleagues (NMRI, Osaka, Japan) to examine the fate of cold (-55 C) CO{sub 2} released at relatively shallow ocean depth. (4) Carried out two short cruises in collaboration with Dr. Costas Tsouris, ORNL, to field test an injection nozzle designed to transform liquid CO{sub 2} into a hydrate slurry at {approx}1000m depth. (5) In collaboration with Prof. Jill Pasteris (Washington University) we have successfully accomplished the first field test of a deep ocean laser Raman spectrometer for probing in situ the physical chemistry of the CO{sub 2} system. (6) Submitted the first major paper on biological impacts as determined from our field studies. (7) Submitted a paper on our measurements of the fate of a rising stream of liquid CO{sub 2} droplets to Environmental Science & Technology. (8) Have had accepted for publication in Eos the first brief account of the laser Raman spectrometer success. (9) Have had two

Seismic velocity structure and spatial distribution of reflection intensity off the Boso Peninsula, Central Japan, revealed by an ocean bottom seismographic experiment

Science.gov (United States)

Kono, Akihiro; Sato, Toshinori; Shinohara, Masanao; Mochizuki, Kimihiro; Yamada, Tomoaki; Uehira, Kenji; Shinbo, Takashi; Machida, Yuuya; Hino, Ryota; Azuma, Ryosuke

2016-04-01

Off the Boso Peninsula, central Japan, where the Sagami Trough is in the south and the Japan Trench is in the east, there is a triple junction where the Pacific plate (PAC), the Philippine Sea plate (PHS) and the Honshu island arc (HIA) meet each other. In this region, the PAC subducts beneath the PHS and the HIA, and the PHS subducts beneath the HIA. Due to the subduction of 2 oceanic plates, numerous seismic events took place in the past. In order to understand these events, it is important to image structure of these plates. Hence, many researchers attempted to reveal the substructure from natural earthquakes and seismic experiments. Because most of the seismometers are placed inland area and the regular seismicity off Boso is inactive, it is difficult to reveal the precise substructure off Boso area using only natural earthquakes. Although several marine seismic experiments using active sources were conducted, vast area remains unclear off Boso Peninsula. In order to improve the situation, a marine seismic experiment, using airgun as an active source, was conducted from 30th July to 4th of August, 2009. The survey line has 216 km length and 20 Ocean Bottom Seismometers (OBSs) were placed on it. We estimated 2-D P-wave velocity structure from the airgun data using the PMDM (Progressive Model Development Method; Sato and Kenett, 2000) and the FAST (First Arrival Seismic Tomography ; Zelt and Barton, 1998). Furthermore, we identified the probable reflection phases from the data and estimated the location of reflectors using Travel time mapping method (Fujie et al. 2006). We found some reflection phases from the data, and the reflectors are located near the region where P-wave velocity is 5.0 km/s. We interpret that the reflectors indicate the plate boundary between the PHS and the HIA. The variation of the intensity of reflection along the upper surface of PHS seems to be consistent with the result from previous reflection seismic experiment conducted by Kimura et

Teaching Sustainabilty in the Setting of a Field-based Class on the Oceans in Captivity

Science.gov (United States)

Macko, Stephen; Tuite, Michael; O'Connell, Matthew

2013-04-01

Sustainability awareness is increasingly a subject in educational settings. Marine science classes are perfect settings of establishing sustainability awareness owing to declining populations of organisms and perceived collapsenin fisheries worldwide. Students in oceanography classes often request more direct exposure to actual ocean situations or field trips. During regular session (13 week) or shorter term (4 week) summer classes such long trips are logistically difficult owing to large numbers of students involved or timing. This new approach to such a course supplement addresses the requests by utilizing local resources and short field trips for a limited number of students (20) to locations in which Ocean experiences are available, and are often supported through education and outreach components. The vision of the class was a mixture of classroom time, readings, along with paper and laboratories. In addition short day-long trips to locations where the ocean was "captured" were also used to supplement the experience as well as speakers involved with aquaculture ("cultivated") Central Virginia is a fortunate location for such a class, with close access for "day travel" to the Chesapeake Bay and numerous field stations, museums with ocean-based exhibits (the Smithsonian and National Zoo) that address both extant and extinct Earth history, as well as national/state aquaria in Baltimore, Washington and Virginia Beach. Furthermore, visits to local seafood markets at local grocery stores, or larger city markets) enhance the exposure to productivity in the ocean, and viability of the fisheries sustainability. The course could then address not only the particulars of the marine science, but also aspects of sustainability with discussions on ethics, including keeping animals in captivity or overfishing of particular species and the special difficulties that arise from captive or culturing ocean populations. In addition, the class was encouraged to post web

Atmospheric Concentrations of Persistent Organic Pollutants in the Southern Ocean

Science.gov (United States)

Vlahos, P.; Edson, J.; Cifuentes, A.; McGillis, W. R.; Zappa, C.

2008-12-01

Long-range transport of persistent organic pollutant (POPs) is a global concern. Remote regions such as the Southern Ocean are greatly under-sampled though critical components in understanding POPs cycling. Over 20 high-volume air samples were collected in the Southern Ocean aboard the RV Brown during the GASEX III experiment between Mar 05 to April 9 2008. The relatively stationary platform (51S,38W) enabled the collection of a unique atmospheric time series at this open ocean station. Air sampling was also conducted across transects from Punto Arenas, Chile and to Montevideo, Uruguay. Samples were collected using glass sleeves packed with poly-urethane foam plugs and C-18 resin in order to collect target organic pollutants (per-fluorinated compounds, currently and historically used pesticides) in this under-sampled region. Here we present POPs concentrations and trends over the sampled period and compare variations with air parcel back trajectories to establish potential origins of their long-range transport.

Anthropogenic radionuclides in the Arctic Ocean. Distribution and pathways

Energy Technology Data Exchange (ETDEWEB)

Josefsson, Dan

1998-05-01

Anthropogenic radionuclide concentrations have been determined in seawater and sediment samples collected in 1991, 1994 and 1996 in the Eurasian Arctic shelf and interior. Global fallout, releases from European reprocessing plants and the Chernobyl accident are identified as the three main sources. From measurements in the Eurasian shelf seas it is concluded that the total input of {sup 134}Cs, {sup 137}Cs and {sup 90}Sr from these sources has been decreasing during the 1990`s, while {sup 129}I has increased. The main fraction of the reprocessing and Chernobyl activity found in Arctic Ocean surface layer is transported from the Barents Sea east along the Eurasian Arctic shelf seas to the Laptev Sea before entering the Nansen Basin. This inflow results in highest {sup 137}Cs, {sup 129}I and {sup 90}Sr concentrations in the Arctic Ocean surface layers, and continuously decreasing concentrations with depth. Chernobyl-derived {sup 137}Cs appeared in the central parts of the Arctic Ocean around 1991, and in the mid 1990`s the fraction to total {sup 137}Cs was approximately 30% in the entire Eurasian Arctic region. The transfer times for releases from Sellafield are estimated to be 5-7 years to the SE Barents Sea, 7-9 years to the Kara Sea, 10-11 years to the Laptev Sea and 12-14 years to the central Arctic Ocean. Global fallout is the primary source of plutonium with highest concentrations found in the Atlantic layer of the Arctic Ocean. When transported over the shallow shelf seas, particle reactive transuranic elements experience an intense scavenging. A rough estimate shows that approximately 75% of the plutonium entering the Kara and Laptev Seas are removed to the sediment. High seasonal riverine input of {sup 239}, {sup 240}Pu is observed near the mouths of the large Russian rivers. Sediment inventories show much higher concentrations on the shelf compared to the deep Arctic Ocean. This is primarily due to the low particle flux in the open ocean

Anthropogenic radionuclides in the Arctic Ocean. Distribution and pathways

International Nuclear Information System (INIS)

Josefsson, Dan

1998-05-01

Anthropogenic radionuclide concentrations have been determined in seawater and sediment samples collected in 1991, 1994 and 1996 in the Eurasian Arctic shelf and interior. Global fallout, releases from European reprocessing plants and the Chernobyl accident are identified as the three main sources. From measurements in the Eurasian shelf seas it is concluded that the total input of 134 Cs, 137 Cs and 90 Sr from these sources has been decreasing during the 1990's, while 129 I has increased. The main fraction of the reprocessing and Chernobyl activity found in Arctic Ocean surface layer is transported from the Barents Sea east along the Eurasian Arctic shelf seas to the Laptev Sea before entering the Nansen Basin. This inflow results in highest 137 Cs, 129 I and 90 Sr concentrations in the Arctic Ocean surface layers, and continuously decreasing concentrations with depth. Chernobyl-derived 137 Cs appeared in the central parts of the Arctic Ocean around 1991, and in the mid 1990's the fraction to total 137 Cs was approximately 30% in the entire Eurasian Arctic region. The transfer times for releases from Sellafield are estimated to be 5-7 years to the SE Barents Sea, 7-9 years to the Kara Sea, 10-11 years to the Laptev Sea and 12-14 years to the central Arctic Ocean. Global fallout is the primary source of plutonium with highest concentrations found in the Atlantic layer of the Arctic Ocean. When transported over the shallow shelf seas, particle reactive transuranic elements experience an intense scavenging. A rough estimate shows that approximately 75% of the plutonium entering the Kara and Laptev Seas are removed to the sediment. High seasonal riverine input of 239 , 240 Pu is observed near the mouths of the large Russian rivers. Sediment inventories show much higher concentrations on the shelf compared to the deep Arctic Ocean. This is primarily due to the low particle flux in the open ocean

Freshening of Antarctic Intermediate Water in the South Atlantic Ocean in 2005–2014

OpenAIRE

Yao, Wenjun; Shi, Jiuxin

2016-01-01

Basin-scaled freshening of Antarctic Intermediate Water (AAIW) is reported to have dominated South Atlantic Ocean during period from 2005 to 2014, as shown by the gridded monthly means Argo (Array for Real-time Geostrophic Oceanography) data. The relevant investigation was also revealed by two transatlantic occupations of repeated section along 30° S, from World Ocean Circulation Experiment Hydrographic Program. Freshening of the AAIW was compensated by the opposing salinity increase o...

Spatial competition dynamics between reef corals under ocean acidification

Science.gov (United States)

Horwitz, Rael; Hoogenboom, Mia O.; Fine, Maoz

2017-01-01

Climate change, including ocean acidification (OA), represents a major threat to coral-reef ecosystems. Although previous experiments have shown that OA can negatively affect the fitness of reef corals, these have not included the long-term effects of competition for space on coral growth rates. Our multispecies year-long study subjected reef-building corals from the Gulf of Aqaba (Red Sea) to competitive interactions under present-day ocean pH (pH 8.1) and predicted end-of-century ocean pH (pH 7.6). Results showed coral growth is significantly impeded by OA under intraspecific competition for five out of six study species. Reduced growth from OA, however, is negligible when growth is already suppressed in the presence of interspecific competition. Using a spatial competition model, our analysis indicates shifts in the competitive hierarchy and a decrease in overall coral cover under lowered pH. Collectively, our case study demonstrates how modified competitive performance under increasing OA will in all likelihood change the composition, structure and functionality of reef coral communities.

Impacts of Interannual Ocean Circulation Variability on Japanese Eel Larval Migration in the Western North Pacific Ocean.

Directory of Open Access Journals (Sweden)

Yu-Lin Chang

Full Text Available The Japanese eel larvae hatch near the West Mariana Ridge seamount chain and travel through the North Equatorial Current (NEC, the Kuroshio, and the Subtropical Countercurrent (STCC region during their shoreward migration toward East Asia. The interannual variability of circulation over the subtropical and tropical regions of the western North Pacific Ocean is affected by the Philippines-Taiwan Oscillation (PTO. This study examines the effect of the PTO on the Japanese eel larval migration routes using a three-dimensional (3D particle tracking method, including vertical and horizontal swimming behavior. The 3D circulation and hydrography used for particle tracking are from the ocean circulation reanalysis produced by the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2. Our results demonstrate that bifurcation of the NEC and the strength and spatial variation of the Kuroshio affect the distribution and migration of eel larvae. During the positive phase of PTO, more virtual eels ("v-eels" can enter the Kuroshio to reach the south coast of Japan and more v-eels reach the South China Sea through the Luzon Strait; the stronger and more offshore swing of the Kuroshio in the East China Sea leads to fewer eels entering the East China Sea and the onshore movement of the Kuroshio to the south of Japan brings the eels closer to the Japanese coast. Significant differences in eel migration routes and distributions regulated by ocean circulation in different PTO phases can also affect the otolith increment. The estimated otolith increment suggests that eel age tends to be underestimated after six months of simulation due to the cooler lower layer temperature. Underestimation is more significant in the positive PTO years due to the wide distribution in higher latitudes than in the negative PTO years.

Impacts of Interannual Ocean Circulation Variability on Japanese Eel Larval Migration in the Western North Pacific Ocean.

Science.gov (United States)

Chang, Yu-Lin; Sheng, Jinyu; Ohashi, Kyoko; Béguer-Pon, Mélanie; Miyazawa, Yasumasa

2015-01-01

The Japanese eel larvae hatch near the West Mariana Ridge seamount chain and travel through the North Equatorial Current (NEC), the Kuroshio, and the Subtropical Countercurrent (STCC) region during their shoreward migration toward East Asia. The interannual variability of circulation over the subtropical and tropical regions of the western North Pacific Ocean is affected by the Philippines-Taiwan Oscillation (PTO). This study examines the effect of the PTO on the Japanese eel larval migration routes using a three-dimensional (3D) particle tracking method, including vertical and horizontal swimming behavior. The 3D circulation and hydrography used for particle tracking are from the ocean circulation reanalysis produced by the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2). Our results demonstrate that bifurcation of the NEC and the strength and spatial variation of the Kuroshio affect the distribution and migration of eel larvae. During the positive phase of PTO, more virtual eels ("v-eels") can enter the Kuroshio to reach the south coast of Japan and more v-eels reach the South China Sea through the Luzon Strait; the stronger and more offshore swing of the Kuroshio in the East China Sea leads to fewer eels entering the East China Sea and the onshore movement of the Kuroshio to the south of Japan brings the eels closer to the Japanese coast. Significant differences in eel migration routes and distributions regulated by ocean circulation in different PTO phases can also affect the otolith increment. The estimated otolith increment suggests that eel age tends to be underestimated after six months of simulation due to the cooler lower layer temperature. Underestimation is more significant in the positive PTO years due to the wide distribution in higher latitudes than in the negative PTO years.

Chemical and physical data from Niskin bottles from the World Ocean Circulation Experiment and Joint Global Ocean Flux Study Hawaii Ocean Time-series (HOT) database during 1988-1998 in the North Pacific Ocean 100 miles north of Oahu, Hawaii (NODC Accession 9900208)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The HOT program makes repeated observations of the physics, biology and chemistry at a site approximately 100 km north of Oahu, Hawaii. Two stations are visited...

Ocean acidification impacts on black sea bass and scup embryos, responses of finfish in laboratory experiments

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Black sea bass (Centropristis striata) and scup (Stenotomus chrysops) compose important recreational and commercial fisheries along the United States Atlantic coast....

Communicating Ocean Science at the Lower-Division Level

Science.gov (United States)

Coopersmith, A.

2011-12-01

Pacific Ocean Literacy for Youth, Publics, Professionals, and Scientists (POLYPPS) is an NSF-funded collaboration between the University of Hawai`i and the Center for Ocean Science Education Excellence (COSEE) - California, which is based at the Lawrence Hall of Science, University of California - Berkeley. One of the objectives of this project is to instutionalize ocean science communications courses at colleges and universities in Hawai`i. Although the focus of most of these communications courses has been on training graduate students and scientists, lower-division students interested in the ocean sciences are finding this background helpful. At the University of Hawai`i Maui College there are several marine science courses and certificate programs that require students to interact with the public through internships, research assistantships, and course-related service-learning projects. Oceanography 270, Communicating Ocean Science, is now offered to meet the needs of these students who engage with the public in informal educational settings. Other students who enroll in this course have a general interest in the marine environment and are considering careers in K-12 formal education. This course gives this group of students an opportunity to explore formal education by assisting classroom teachers and preparing and presenting problem-based, hands-on, inquiry activities. Employers at marine-related businesses and in the tourist industry have welcomed this course with a focus on communication skills and indicate that they prefer to hire local people with strong backgrounds in marine and natural sciences. A basic premise of POLYPPS is that science education must draw not only from the latest advances in science and technology but also from the cultural contexts in which the learners are embedded and that this will achieve increased understanding and stewardship of ocean environments. Students in Oceanography 270 integrate traditional Hawaiian knowledge into their

Remote sensing of ocean surface currents: a review of what is being observed and what is being assimilated

Science.gov (United States)

Isern-Fontanet, Jordi; Ballabrera-Poy, Joaquim; Turiel, Antonio; García-Ladona, Emilio

2017-10-01

Ocean currents play a key role in Earth's climate - they impact almost any process taking place in the ocean and are of major importance for navigation and human activities at sea. Nevertheless, their observation and forecasting are still difficult. First, no observing system is able to provide direct measurements of global ocean currents on synoptic scales. Consequently, it has been necessary to use sea surface height and sea surface temperature measurements and refer to dynamical frameworks to derive the velocity field. Second, the assimilation of the velocity field into numerical models of ocean circulation is difficult mainly due to lack of data. Recent experiments that assimilate coastal-based radar data have shown that ocean currents will contribute to increasing the forecast skill of surface currents, but require application in multidata assimilation approaches to better identify the thermohaline structure of the ocean. In this paper we review the current knowledge in these fields and provide a global and systematic view of the technologies to retrieve ocean velocities in the upper ocean and the available approaches to assimilate this information into ocean models.

Impacts of Ocean Acidification

Energy Technology Data Exchange (ETDEWEB)

Bijma, Jelle (Alfred Wegener Inst., D-27570 Bremerhaven (Germany)) (and others)

2009-08-15

There is growing scientific evidence that, as a result of increasing anthropogenic carbon dioxide (CO{sub 2}) emissions, absorption of CO{sub 2} by the oceans has already noticeably increased the average oceanic acidity from pre-industrial levels. This global threat requires a global response. According to the Intergovernmental Panel on Climate Change (IPCC), continuing CO{sub 2} emissions in line with current trends could make the oceans up to 150% more acidic by 2100 than they were at the beginning of the Anthropocene. Acidification decreases the ability of the ocean to absorb additional atmospheric CO{sub 2}, which implies that future CO{sub 2} emissions are likely to lead to more rapid global warming. Ocean acidification is also problematic because of its negative effects on marine ecosystems, especially marine calcifying organisms, and marine resources and services upon which human societies largely depend such as energy, water, and fisheries. For example, it is predicted that by 2100 around 70% of all cold-water corals, especially those in the higher latitudes, will live in waters undersaturated in carbonate due to ocean acidification. Recent research indicates that ocean acidification might also result in increasing levels of jellyfish in some marine ecosystems. Aside from direct effects, ocean acidification together with other global change-induced impacts such as marine and coastal pollution and the introduction of invasive alien species are likely to result in more fragile marine ecosystems, making them more vulnerable to other environmental impacts resulting from, for example, coastal deforestation and widescale fisheries. The Marine Board-ESF Position Paper on the Impacts of Climate Change on the European Marine and Coastal Environment - Ecosystems indicated that presenting ocean acidification issues to policy makers is a key issue and challenge. Indeed, as the consequences of ocean acidification are expected to emerge rapidly and drastically, but are

The role of ocean-atmosphere interaction in Typhoon Sinlaku (2008) using a regional coupled data assimilation system

Science.gov (United States)

Wada, Akiyoshi; Kunii, Masaru

2017-05-01

For improving analyses of tropical cyclone (TC) and sea surface temperature (SST) and thereby TC simulations, a regional mesoscale strongly coupled atmosphere-ocean data assimilation system was developed with the local ensemble transform Kalman filter (LETKF) implemented with the Japan Meteorological Agency's nonhydrostatic model (NHM) coupled with a multilayer ocean model and the third-generation ocean wave model. The NHM-LETKF coupled data assimilation system was applied to Typhoon Sinlaku (2008) along with the original NHM-LETKF system to investigate the sensitivity of Sinlaku to SST assimilation with the Level 2 Pre-processed (L2P) standard product of satellite SST. SST calculated in the coupled-assimilation experiment with the coupled data assimilation system and the satellite SST (CPL) showed a better correlation with Optimally Interpolated SST than SST used in the control experiment with the original NHM-LETKF (CNTL) and SST calculated in the succession experiment with the coupled system without satellite SST (SUCC). The time series in the CPL experiment well captured the variation in the SST observed at the Kuroshio Extension Observation buoy site. In addition, TC-induced sea surface cooling was analyzed more realistically in the CPL experiment than that in the CNTL and SUCC experiments. However, the central pressure analyzed in each three experiments was overestimated compared with the Regional Specialized Meteorological Center Tokyo best-track central pressure, mainly due to the coarse horizontal resolution of 15 km. The 96 h TC simulations indicated that the CPL experiment provided more favorable initial and boundary conditions than the CNTL experiment to simulate TC tracks more accurately.

Modelling the inorganic ocean carbon cycle under past and future climate change

International Nuclear Information System (INIS)

Ewan, T.L.

2004-01-01

This study used a coupled ocean-atmosphere-sea ice model with an inorganic carbon component to examine the inorganic ocean carbon cycle with particular reference to how climate feedback influences future uptake. In the last 150 years, the increase in atmosphere carbon dioxide (CO 2 ) concentrations have been higher than any time during the Earth's history. Although the oceans are the largest sink for carbon dioxide, it is not know how the ocean carbon cycle will respond to increasing anthropogenic carbon dioxide concentrations in the future. Climate feedbacks could potentially reduce further uptake of carbon by the ocean. In addition to examining past climate transitions, including both abrupt and glacial-interglacial climate transitions, this study also examined the sensitivity of the inorganic carbon cycle to increased atmospheric carbon dioxide. Atmospheric carbon dioxide levels were also projected under a range of global warming scenarios. Most simulations identified a transient weakening of the North Atlantic and increased sea surface temperatures (SST). These positive feedbacks act on the carbon system to reduce uptake. However, the ocean has the capacity to take up 65 to 75 per cent of the anthropogenic carbon dioxide increases. An analysis of climate feedback on future carbon uptake shows that oceans store 7 per cent more carbon when there are no climate feedbacks acting on the system. Sensitivity experiments using the Gent McWilliams parameterization for mixing associated with mesoscale eddies show a further 6 per cent increase in oceanic uptake. Inclusion of sea ice dynamics resulted in a 2 per cent difference in uptake. This study also examined changes in atmospheric carbon dioxide concentration that occur during abrupt climate change events. Changes in ocean circulation and carbon solubility cause significant increases in atmospheric carbon dioxide concentrations when melt water episodes are simulated in both hemispheres. The response of the carbon

EPOCA/EUR-OCEANS data compilation on the biological and biogeochemical responses to ocean acidification

OpenAIRE

Nisumaa Anne-Marin; Pesant Stephane; Bellerby Richard G J; Delille Bruno; Middelburg Jack J; Orr James C; Riebesell Ulf; Tyrrell Toby; Wolf-Gladrow Dieter A; Gattuso Jean-Pierre

2010-01-01

The uptake of anthropogenic CO₂ by the oceans has led to a rise in the oceanic partial pressure of CO₂, and to a decrease in pH and carbonate ion concentration. This modification of the marine carbonate system is referred to as ocean acidification. Numerous papers report the effects of ocean acidification on marine organisms and communities but few have provided details concerning full carbonate chemistry and complementary observations. Additional...

Ocean carbon uptake and storage

International Nuclear Information System (INIS)

Tilbrook, Bronte

2007-01-01

Full text: The ocean contains about 95% of the carbon in the atmosphere, ocean and land biosphere system, and is of fundamental importance in regulating atmospheric carbon dioxide concentrations. In the 1990s an international research effort involving Australia was established to determine the uptake and storage of anthropogenic C02 for all major ocean basins. The research showed that about 118 of the 244 + 20 billion tons of the anthropogenic carbon emitted through fossil fuel burning and cement production has been stored in the ocean since preindustrial times, thus helping reduce the rate of increase in atmospheric C02. The research also showed the terrestrial biosphere has been a small net source of C02 (39 ± 28 billion tons carbon) to the atmosphere over the same period. About 60% of the total ocean inventory of the anthropogenic C02 was found in the Southern Hemisphere, with most in the 30 0 S to 50 0 S latitude band. This mid-latitude band is where surface waters are subducted as Mode and Intermediate waters, which is a major pathway controlling ocean C02 uptake. High storage (23% of the total) also occurs in the North Atlantic, associated with deep water formation in that basin. The ocean uptake and storage is expected to increase in the coming decades as atmospheric C02 concentrations rise. However, a number of feedback mechanisms associated with surface warming, changes in circulation, and biological effects are likely to impact on the uptake capacity. The accumulation or storage-of the C02 in the ocean is also the major driver of ocean acidification with potential to disrupt marine ecosystems. This talk will describe the current understanding of the ocean C02 uptake and storage and a new international research strategy to detect how the ocean uptake and storage will evolve on interannual through decadal scales. Understanding the ocean response to increasing atmospheric C02 will be a key element in managing future C02 increases and establishing

Modelling size-fractionated primary production in the Atlantic Ocean from remote sensing

Science.gov (United States)

Brewin, Robert J. W.; Tilstone, Gavin H.; Jackson, Thomas; Cain, Terry; Miller, Peter I.; Lange, Priscila K.; Misra, Ankita; Airs, Ruth L.

2017-11-01

Marine primary production influences the transfer of carbon dioxide between the ocean and atmosphere, and the availability of energy for the pelagic food web. Both the rate and the fate of organic carbon from primary production are dependent on phytoplankton size. A key aim of the Atlantic Meridional Transect (AMT) programme has been to quantify biological carbon cycling in the Atlantic Ocean and measurements of total primary production have been routinely made on AMT cruises, as well as additional measurements of size-fractionated primary production on some cruises. Measurements of total primary production collected on the AMT have been used to evaluate remote-sensing techniques capable of producing basin-scale estimates of primary production. Though models exist to estimate size-fractionated primary production from satellite data, these have not been well validated in the Atlantic Ocean, and have been parameterised using measurements of phytoplankton pigments rather than direct measurements of phytoplankton size structure. Here, we re-tune a remote-sensing primary production model to estimate production in three size fractions of phytoplankton (10 μm) in the Atlantic Ocean, using measurements of size-fractionated chlorophyll and size-fractionated photosynthesis-irradiance experiments conducted on AMT 22 and 23 using sequential filtration-based methods. The performance of the remote-sensing technique was evaluated using: (i) independent estimates of size-fractionated primary production collected on a number of AMT cruises using 14C on-deck incubation experiments and (ii) Monte Carlo simulations. Considering uncertainty in the satellite inputs and model parameters, we estimate an average model error of between 0.27 and 0.63 for log10-transformed size-fractionated production, with lower errors for the small size class (10 μm), and errors generally higher in oligotrophic waters. Application to satellite data in 2007 suggests the contribution of cells 2 μm to total

Ocean acoustic tomography

International Nuclear Information System (INIS)

Cornuelle, Bruce D; Worcester, Peter F; Dzieciuch, Matthew A

2008-01-01

Ocean acoustic tomography (OAT) was proposed in 1979 by Walter Munk and Carl Wunsch as an analogue to x-ray computed axial tomography for the oceans. The oceans are opaque to most electromagnetic radiation, but there is a strong acoustic waveguide, and sound can propagate for 10 Mm and more with distinct multiply-refracted ray paths. Transmitting broadband pulses in the ocean leads to a set of impulsive arrivals at the receiver which characterize the impulse response of the sound channel. The peaks observed at the receiver are assumed to represent the arrival of energy traveling along geometric ray paths. These paths can be distinguished by arrival time, and by arrival angle when a vertical array of receivers is available. Changes in ray arrival time can be used to infer changes in ocean structure. Ray travel time measurements have been a mainstay of long-range acoustic measurements, but the strong sensitivity of ray paths to range-dependent sound speed perturbations makes the ray sampling functions uncertain in real cases. In the ray approximation travel times are sensitive to medium changes only along the corresponding eigenrays. Ray theory is an infinite-frequency approximation, and its eikonal equation has nonlinearities not found in the acoustic wave equation. We build on recent seismology results (kernels for body wave arrivals in the earth) to characterize the kernel for converting sound speed change in the ocean to travel time changes using more complete propagation physics. Wave-theoretic finite frequency kernels may show less sensitivity to small-scale sound speed structure.

Anomaly transform methods based on total energy and ocean heat content norms for generating ocean dynamic disturbances for ensemble climate forecasts

Science.gov (United States)

Romanova, Vanya; Hense, Andreas

2017-08-01

In our study we use the anomaly transform, a special case of ensemble transform method, in which a selected set of initial oceanic anomalies in space, time and variables are defined and orthogonalized. The resulting orthogonal perturbation patterns are designed such that they pick up typical balanced anomaly structures in space and time and between variables. The metric used to set up the eigen problem is taken either as the weighted total energy with its zonal, meridional kinetic and available potential energy terms having equal contributions, or the weighted ocean heat content in which a disturbance is applied only to the initial temperature fields. The choices of a reference state for defining the initial anomalies are such that either perturbations on seasonal timescales and or on interannual timescales are constructed. These project a-priori only the slow modes of the ocean physical processes, such that the disturbances grow mainly in the Western Boundary Currents, in the Antarctic Circumpolar Current and the El Nino Southern Oscillation regions. An additional set of initial conditions is designed to fit in a least square sense data from global ocean reanalysis. Applying the AT produced sets of disturbances to oceanic initial conditions initialized by observations of the MPIOM-ESM coupled model on T63L47/GR15 resolution, four ensemble and one hind-cast experiments were performed. The weighted total energy norm is used to monitor the amplitudes and rates of the fastest growing error modes. The results showed minor dependence of the instabilities or error growth on the selected metric but considerable change due to the magnitude of the scaling amplitudes of the perturbation patterns. In contrast to similar atmospheric applications, we find an energy conversion from kinetic to available potential energy, which suggests a different source of uncertainty generation in the ocean than in the atmosphere mainly associated with changes in the density field.

Ocean deoxygenation in a warming world.

Science.gov (United States)

Keeling, Ralph E; Körtzinger, Arne; Gruber, Nicolas

2010-01-01

Ocean warming and increased stratification of the upper ocean caused by global climate change will likely lead to declines in dissolved O2 in the ocean interior (ocean deoxygenation) with implications for ocean productivity, nutrient cycling, carbon cycling, and marine habitat. Ocean models predict declines of 1 to 7% in the global ocean O2 inventory over the next century, with declines continuing for a thousand years or more into the future. An important consequence may be an expansion in the area and volume of so-called oxygen minimum zones, where O2 levels are too low to support many macrofauna and profound changes in biogeochemical cycling occur. Significant deoxygenation has occurred over the past 50 years in the North Pacific and tropical oceans, suggesting larger changes are looming. The potential for larger O2 declines in the future suggests the need for an improved observing system for tracking ocean 02 changes.

The ocean planet.

Science.gov (United States)

Hinrichsen, D

1998-01-01

The Blue Planet is 70% water, and all but 3% of it is salt water. Life on earth first evolved in the primordial soup of ancient seas, and though today's seas provide 99% of all living space on the planet, little is known about the world's oceans. However, the fact that the greatest threats to the integrity of our oceans come from land-based activities is becoming clear. Humankind is in the process of annihilating the coastal and ocean ecosystems and the wealth of biodiversity they harbor. Mounting population and development pressures have taken a grim toll on coastal and ocean resources. The trend arising from such growth is the chronic overexploitation of marine resources, whereby rapidly expanding coastal populations and the growth of cities have contributed to a rising tide of pollution in nearly all of the world's seas. This crisis is made worse by government inaction and a frustrating inability to enforce existing coastal and ocean management regulations. Such inability is mainly because concerned areas contain so many different types of regulations and involve so many levels of government, that rational planning and coordination of efforts are rendered impossible. Concerted efforts are needed by national governments and the international community to start preserving the ultimate source of all life on earth.

Synthesis study of an erosion hot spot, Ocean Beach, California

Science.gov (United States)

Barnard, Patrick L.; Hansen, Jeff E.; Erikson, Li H.

2012-01-01

A synthesis of multiple coastal morphodynamic research efforts is presented to identify the processes responsible for persistent erosion along a 1-km segment of 7-km-long Ocean Beach in San Francisco, California. The beach is situated adjacent to a major tidal inlet and in the shadow of the ebb-tidal delta at the mouth of San Francisco Bay. Ocean Beach is exposed to a high-energy wave climate and significant alongshore variability in forcing introduced by varying nearshore bathymetry, tidal forcing, and beach morphology (e.g., beach variably backed by seawall, dunes, and bluffs). In addition, significant regional anthropogenic factors have influenced sediment supply and tidal current strength. A variety of techniques were employed to investigate the erosion at Ocean Beach, including historical shoreline and bathymetric analysis, monthly beach topographic surveys, nearshore and regional bathymetric surveys, beach and nearshore grain size analysis, two surf-zone hydrodynamic experiments, four sets of nearshore wave and current experiments, and several numerical modeling approaches. Here, we synthesize the results of 7 years of data collection to lay out the causes of persistent erosion, demonstrating the effectiveness of integrating an array of data sets covering a huge range of spatial scales. The key findings are as follows: anthropogenic influences have reduced sediment supply from San Francisco Bay, leading to pervasive contraction (i.e., both volume and area loss) of the ebb-tidal delta, which in turn reduced the regional grain size and modified wave focusing patterns along Ocean Beach, altering nearshore circulation and sediment transport patterns. In addition, scour associated with an exposed sewage outfall pipe causes a local depression in wave heights, significantly modifying nearshore circulation patterns that have been shown through modeling to be key drivers of persistent erosion in that area.

Evaluation of the MODIS Aerosol Retrievals over Ocean and Land during CLAMS.

Science.gov (United States)

Levy, R. C.; Remer, L. A.; Martins, J. V.; Kaufman, Y. J.; Plana-Fattori, A.; Redemann, J.; Wenny, B.

2005-04-01

The Chesapeake Lighthouse Aircraft Measurements for Satellites (CLAMS) experiment took place from 10 July to 2 August 2001 in a combined ocean-land region that included the Chesapeake Lighthouse [Clouds and the Earth's Radiant Energy System (CERES) Ocean Validation Experiment (COVE)] and the Wallops Flight Facility (WFF), both along coastal Virginia. This experiment was designed mainly for validating instruments and algorithms aboard the Terra satellite platform, including the Moderate Resolution Imaging Spectroradiometer (MODIS). Over the ocean, MODIS retrieved aerosol optical depths (AODs) at seven wavelengths and an estimate of the aerosol size distribution. Over the land, MODIS retrieved AOD at three wavelengths plus qualitative estimates of the aerosol size. Temporally coincident measurements of aerosol properties were made with a variety of sun photometers from ground sites and airborne sites just above the surface. The set of sun photometers provided unprecedented spectral coverage from visible (VIS) to the solar near-infrared (NIR) and infrared (IR) wavelengths. In this study, AOD and aerosol size retrieved from MODIS is compared with similar measurements from the sun photometers. Over the nearby ocean, the MODIS AOD in the VIS and NIR correlated well with sun-photometer measurements, nearly fitting a one-to-one line on a scatterplot. As one moves from ocean to land, there is a pronounced discontinuity of the MODIS AOD, where MODIS compares poorly to the sun-photometer measurements. Especially in the blue wavelength, MODIS AOD is too high in clean aerosol conditions and too low under larger aerosol loadings. Using the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) radiative code to perform atmospheric correction, the authors find inconsistency in the surface albedo assumptions used by the MODIS lookup tables. It is demonstrated how the high bias at low aerosol loadings can be corrected. By using updated urban/industrial aerosol

The Southern Ocean's role in ocean circulation and climate transients

Science.gov (United States)

Thompson, A. F.; Stewart, A.; Hines, S.; Adkins, J. F.

2017-12-01

The ventilation of deep and intermediate density classes at the surface of the Southern Ocean impacts water mass modification and the air-sea exchange of heat and trace gases, which in turn influences the global overturning circulation and Earth's climate. Zonal variability occurs along the Antarctic Circumpolar Current and the Antarctic margins related to flow-topography interactions, variations in surface boundary conditions, and exchange with northern basins. Information about these zonal variations, and their impact on mass and tracer transport, are suppressed when the overturning is depicted as a two-dimensional (depth-latitude) streamfunction. Here we present an idealized, multi-basin, time-dependent circulation model that applies residual circulation theory in the Southern Ocean and allows for zonal water mass transfer between different ocean basins. This model efficiently determines the temporal evolution of the ocean's stratification, ventilation and overturning strength in response to perturbations in the external forcing. With this model we explore the dynamics that lead to transitions in the circulation structure between multiple, isolated cells and a three-dimensional, "figure-of-eight," circulation in which traditional upper and lower cells are interleaved. The transient model is also used to support a mechanistic explanation of the hemispheric asymmetry and phase lag associated with Dansgaard-Oeschger (DO) events during the last glacial period. In particular, the 200 year lag in southern hemisphere temperatures, following a perturbation in North Atlantic deep water formation, depends critically on the migration of Southern Ocean isopycnal outcropping in response to low-latitude stratification changes. Our results provide a self-consistent dynamical framework to explain various ocean overturning transitions that have occurred over the Earth's last 100,000 years, and motivate an exploration of these mechanisms in more sophisticated climate models.

Controlled environment experiments in pollution studies

Energy Technology Data Exchange (ETDEWEB)

Zeitzschel, B

1978-12-01

In the last decade society has become aware of the increasing negative effects of human waste products introduced to the oceans. There is proof evidence, at least for some areas of the world ocean, that the marine environment is seriously in danger. The scientific community is very concerned, arguing that there is an urgent need for basic research in this field because too little is known on the harzardous effects of man-made pollutants on the structure and functioning of marine ecosystems. There are two wanys to perform experiments under conrolled environment conditions: (1) in the laboratory; (2) in in-situ experiments with enclosures. Most laboratory experiments are designed to study the influence and the tolerance spectrum of specific pollutants, e.g. copper or DDT, on any specific organism, e.g. a mussel or a fish. In these experiments it is fairly difficult to simulate natural conditions. The concentrations of the pollutants are generally fairly high, often several orders of magnitude higher than in the ocean. It is questionable if the results from these experiments can be extrapolated to nature. In the second approach (enclosures of various sizes in-situ or in landbased facilities), fibre-glass containers and plastic bags have been used successfully in the last years, e.g. in the UK, USA, Canada, France, and W. Germany. The main goal of these experiments is to study the long-term effect of low-level perturbations on natural populations of the pelagic or benthic ecosystem. Examples of recent results are discussed in detail. 33 references.

Floating Classroom Outreach as an Introduction to Ocean Studies

Science.gov (United States)

McFadden, M.

2016-02-01

Many children and young adults living within only one hour of the coast never have the opportunity to explore a beach or go out on a boat because of financial challenges or lack of transportation.These types of experiences are the spark that helped many ocean scientists become fascinated with the ocean and later pursue a career related to the ocean. This presentation will discuss a variety of outreach projects and the efficacy of each. Projects vary in age, complexity and cost. These projects include a Beach Clean-Up open to students and their families at a community college organized by a campus volunteer group with a focus on social issues, a Marine Biology and Physical Oceanography class joint floating classroom trip open to college students to introduce non-STEM students to marine science in an exciting setting, and an education outreach trip for 8-12 years old children from the Boys and Girls Club in Newport, RI in collaboration with The International SeaKeepers Society, a non-profit that facilitates ocean research and education by working closely with the yachting community. Emphasis on environmental education in the U.S. has grown considerably over recent years, and the development of unique and innovative approaches to hands-on marine science education are needed to excite students to explore the marine environment and care about environmental stewardship.

Isotopic versus micrometeorologic ocean CO2 fluxes: A serious conflict

International Nuclear Information System (INIS)

Broecker, W.S.; Ledwell, J.R.; Takahashi, T.; Weiss, R.; Merlivat, L.; Memery, L.; Tsung-Hung Peng; Jahne, B.; Otto Munnich, K.

1986-01-01

Eddy correlation measurements over the ocean give CO 2 fluxes an order of magnitude or more larger than expected from mass balance or more larger than expected from mass balance measurements using radiocarbon and radon 222. In particular, Smith and Jones (1985) reported large upward and downward fluxes in a surf zone at supersaturations of 15% and attributed them to the equilibration of bubbles at elevated pressures. They argue that even on the open ocean such bubble injection may create steady state CO 2 supersaturations and that inferences of fluxes based on air-sea pCO 2 differences and radon exchange velocities must be made with caution. We defend the global average CO 2 exchange rate determined by three independent radioisotopic means: prebomb radiocarbon inventories; global surveys of mixed layer radon deficits; and oceanic uptake of bomb-produced radiocarbon. We argue that laboratory and lake data do not lead one to expect fluxes as large as reported from the eddy correlation technique; that the radon method of determining exchange velocities is indeed useful for estimating CO 2 fluxes; that supersaturations of CO 2 due to bubble injection on the open ocean are negligible; that the hypothesis that Smith and Jones advance cannot account for the fluxes that they report; and that the pCO 2 values reported by Smith and Jones are likely to be systematically much too high. The CO 2 fluxes for the ocean measured to data by the micrometeorological method can be reconciled with neither the observed concentrations of radioisotopes of radon and carbon in the oceans nor the tracer experiments carried out in lakes and in wind/wave tunnels

Operational Ocean Modelling with the Harvard Ocean Prediction System

Science.gov (United States)

2008-11-01

tno.nl TNO-rapportnummer TNO-DV2008 A417 Opdrachtnummer Datum november 2008 Auteur (s) dr. F.P.A. Lam dr. ir. M.W. Schouten dr. L.A. te Raa...area of theory and implementation of numerical schemes and parameterizations, ocean models have grown from experimental tools to full-blown ocean...sound propagation through mesoscale features using 3-D coupled mode theory , Thesis, Naval Postgraduate School, Monterey, USA. 1992. [9] Robinson

77 FR 15052 - National Ocean Council-National Ocean Policy Draft Implementation Plan

Science.gov (United States)

2012-03-14

... charge for Federal agencies to implement the National Ocean Policy, the National Ocean Council developed... dollars a year to the national economy, and are essential to public health and national security. Next...

Experimental design for three interrelated marine ice sheet and ocean model intercomparison projects: MISMIP v. 3 (MISMIP +), ISOMIP v. 2 (ISOMIP +) and MISOMIP v. 1 (MISOMIP1)

Energy Technology Data Exchange (ETDEWEB)

Asay-Davis, Xylar S. [Potsdam Inst. for Climate Impact Research (Germany). Earth System Analysis; Cornford, Stephen L. [Univ. of Bristol (United Kingdom). Centre for Polar Observation and Modelling; Durand, Gaël [Centre National de la Recherche Scientifique (CNRS), Grenoble (France); Univ. of Grenoble (France); Galton-Fenzi, Benjamin K. [Australian Antarctic Division and Antarctic Climate and Ecosystems Cooperative Research Centre, Tasmania (Australia); Gladstone, Rupert M. [Antarctic Climate and Ecosystems Cooperative Research Centre, Tasmania (Australia); ETH Zurich (Switzerland). Research Center for Hydraulic Engineering; Gudmundsson, G. Hilmar [British Antarctic Survey, Cambridge (United Kingdom); Hattermann, Tore [Akvaplan-niva, Tromso (Norway); Helmholtz Centre for Polar and Marine Research, Bremerhaven (Germany). Alfred Wegener Inst.; Holland, David M. [New York Univ. (NYU), NY (United States)' . Courant Inst. of Mathematical Sciences; Holland, Denise [New York Univ. (NYU), Abu Dahabi (United Arab Emirates); Holland, Paul R. [British Antarctic Survey, Cambridge (United Kingdom); Martin, Daniel F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mathiot, Pierre [British Antarctic Survey, Cambridge (United Kingdom); Met Office, Exeter (United Kingdom); Pattyn, Frank [Univ. of Libre, Brussels (Belgium). Lab. of Glaciology; Seroussi, Hélène [California Inst. of Technology (CalTech), Pasadena, CA (United States). Jet Propulsion Lab.

2016-01-01

Coupled ice sheet-ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of marine ice sheets and tidewater glaciers, from process studies to future projections of ice mass loss and sea level rise. The Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP) is a community effort aimed at designing and coordinating a series of model intercomparison projects (MIPs) for model evaluation in idealized setups, model verification based on observations, and future projections for key regions of the West Antarctic Ice Sheet (WAIS).

Here we describe computational experiments constituting three interrelated MIPs for marine ice sheet models and regional ocean circulation models incorporating ice shelf cavities. These consist of ice sheet experiments under the Marine Ice Sheet MIP third phase (MISMIP+), ocean experiments under the Ice Shelf-Ocean MIP second phase (ISOMIP+) and coupled ice sheet-ocean experiments under the MISOMIP first phase (MISOMIP1). All three MIPs use a shared domain with idealized bedrock topography and forcing, allowing the coupled simulations (MISOMIP1) to be compared directly to the individual component simulations (MISMIP+ and ISOMIP+). The experiments, which have qualitative similarities to Pine Island Glacier Ice Shelf and the adjacent region of the Amundsen Sea, are designed to explore the effects of changes in ocean conditions, specifically the temperature at depth, on basal melting and ice dynamics. In future work, differences between model results will form the basis for the evaluation of the participating models.

Thermal Coupling Between the Ocean and Mantle of Europa: Implications for Ocean Convection