Download or read book Modeling the Dispersion of Radioactive Contaminants in the Arctic Using a Coupled Ice Ocean Model written by and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although several countries dispose of their radioactive waste in the world's oceans, recent revelations by the former Soviet Union concerning disposal of radioactive waste in the shallow water of the Kara Sea have created widespread environmental concern. The Yablokov Report or the White Book is the official Russian documentation of source locations, the time of dumping and the amounts and types of radioactive materials that have been dumped. The report states that low level liquid waste was dumped into the Kara and Barents Seas with lesser amounts dumped into the White Sea and the Baltic. Low to intermediate waste was dumped into the Kara and Barents Seas. The material assumed the most environmentally hazardous was solid radioactive waste with spent nuclear fuel. Nuclear reactors containing the spent nuclear fuel were deposited along the eastern coast of Novaya Zemlya island in water with average depths between 20-40 m. Major river/estuary systems located in the Kara and Barents Seas, particularly the larger Ob and Yenisei rivers as well as the smaller Pechora river, are additional sources. The disposal of liquid radioactive waste at the Sellafield site in the Irish Sea has also been suggested as a source of radioactivity for the Barents and the Kara Sea.
Download or read book Nuclear Wastes in the Arctic written by United States. Congress. Office of Technology Assessment and published by . This book was released on 1995 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines enviromental and human health impacts from wastes dumped in Arctic and North Pacific regions, from nuclear contaminants discharged into these environments, and from radioactive releases from both past and future nuclear activities in region.
Download or read book Nuclear wastes in the Arctic an analysis of Arctic and other regional impacts from Soviet nuclear contamination written by and published by DIANE Publishing. This book was released on 1995 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report examines the environmental and human health impacts from wastes dumped into the Arctic and North Pacific regions, from nuclear contaminants discharged into these environments, and from radioactive releases from both past and future nuclear activities in the region. The report presents what is known and unknown about this waste and contamination and how it may affect public health. Because so many factors are involved and science cannot provide absolute answers to many questions, this study emphasizes the need for care, caution, awareness, and prudence. It also stresses the need for a stable and enduring institutional framework and international cooperation for long term observation and monitoring.
Download or read book Arctic Alpine Ecosystems and People in a Changing Environment written by Jon Børre Ørbaek and published by Springer Science & Business Media. This book was released on 2007-01-10 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European Arctic and Alpine regions are experiencing large environmental changes. These changes may have socio-economic effects if the changes affect the bioproduction, which form the basis for the marine and terrestrial food chains. This uniquely multidisciplinary book presents the various aspects of contemporary environmental changes in Arctic and Alpine Regions.
Download or read book Modelling Radioactivity in the Environment written by E.M. Scott and published by Elsevier. This book was released on 2003-05-22 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Just as an environmental model typically will be composed of a number of linked sub-models, representing physical, chemical or biological processes understood to varying degrees, this volume includes a series of linked chapters exemplifying the fundamental nature of environmental radioactivity models in all compartments of the environment. Why is a book on modelling environmental radioactivity necessary? There are many reasons why such a boook is necessary, perhaps the most important that: - modelling is an often misunderstood and maligned activity and this book can provide, to a broad audience, a greater understanding of modelling power but also some of the limitations. - modellers and experimentalists often do not understand and mistrust each other's work yet they are mutually dependent, in the sense that good experimental science can direct good modelling work and vice-versa; we hope that this book can dispel mistrust and engender improved understanding. - there is an increasing reliance on model results in environmental management, yet there is also often misuse and misrepresentation of these results. This book can help to bridge the gap between unrealistic expectations of model power and the realisation of what is possible, practicable and feasible in modelling of environmental radioactivity; and finally, - modelling tools, capacity and power have increased many-fold in a relatively short period of time. Much of this is due to the much-heralded computer revolution, but much is also due to better science. It is useful to consider what gap if any still remains between what is possible and what is necessary.
Download or read book Radioactivity and Pollution in the Nordic Seas and Arctic written by Olaf M. Johannessen and published by Springer Science & Business Media. This book was released on 2011-04-25 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes a new tool called the Generic Model System for simulations and assessment of potential radioactive spreading in the Arctic regions. It considers the present and future potential for spreading of radionuclear pollution from sources such as from the major Russian processing plants as well as from European sources such as the UK Sellafield plant. The book combines the expertise of professionals from the radionuclear and climate-change sciences.
Download or read book Arctic Studies with Coupled Ice Ocean Models written by and published by . This book was released on 1989 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The upper ocean is modeled in the framework of a three dimensional mixed-layer approximation and is coupled to the Hiber thermodynamic dynamic ice model. Two different modeling approaches are used for the interior ocean. In one, the geostrophic velocity is obtained from an inverse, Beta-spiral, type of model. In another, the barotrophic velocity is calculated prognostically. Topography is included in both approaches. The model is initialized form Levitus climatology and is forced by NOGAPS atmospheric forcing. Studies of diurnal and seasonal regimes are performed. The nature of the boundary layer under ice, in the marginal ice zone, and open water is analyzed. Transmission of wind stress through the ice is considered. The resultant Ekman pumping and the forcings of the interior ocean are calculated. In the Greenland Sea and Norwegian Sea areas, major changes in the behavior of the upper ocean are observed from the Arctic Basin outwards. Deep neutrally stable mixed layers tend to occur outside the MIZ. The heat and salt budgets of these regions are computed.
Download or read book Global Environmental Change written by Kirill Y. Kondratyev and published by Springer Science & Business Media. This book was released on 2002-09-11 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing number of published works dedicated to global environmental change leads to the realization that protection of the natural environment has become an urgent problem. The question of working out principles of co evolution of man and nature is being posed with ever-increasing persistence. Scientists in many countries are attempting to find ways of formulating laws governing human processes acting on the environment. Numerous national and international programs regarding biosphere and climate studies contribute to the quest for means of resolving the conflict between human society and nature. However, attempts to find efficient methods of regulating human activity on a global scale encounter principal difficulties. The major difficulty is the lack of an adequate knowledge base pertaining to climatic and biospheric processes as wen as the largely incomplete state of the databases concerning global processes occurring in the atmosphere, in the ocean, and on land. Another difficulty is the inability of modern science to formulate the requirements which must be met by the global databases necessary for reliable evaluation of the state of the environ ment and fore casting its development for sufficiently long time intervals.
Download or read book Proceedings of the ONR NRL Workshop on Modeling the Dispersion of Nuclear Contaminants in the Arctic Seas October 18 19 1994 Monterey California written by Robert Edson and published by . This book was released on 1995 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: A workshop focusing on modeling the dispersion of radionuclides which have been dumped into the Arctic Ocean was held in Monterey, CA, in October 1994. This workshop was sponsored by the Office of Naval Research and hosted by the Naval Research Laboratory. Over 40 participants attended this meeting during which 23 oral presentations were given. The focus of this workshop was on the existing modeling effort within the Arctic Nuclear Waste Assessment program, complementary data sets and the future direction of these efforts. The goal of the workshop was to foster communication through presentations of ongoing work. The intent was that discussions, brought about by these presentations would help the most important processes, effects, and issues that should be addressed by present and future modeling efforts. (AN).
Download or read book Modelling of the Radiological Impact of Radioactive Waste Dumping in the Arctic Seas written by International Arctic Seas Assessment Project and published by . This book was released on 2003-04-01 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Arctic Seas Assessment Project ( ASAP) was launched by the IAEA in 1993 in response to widespread concern arising from reports that the former Soviet Union had dumped radioactive waste in the Arctic Seas for more than thirty years. The objectives of IASAP were to assess the risk to human health and to the environment associated with the radioactive waste disposed of in the Kara and Barents Seas, and to examine the possible remedial actions related to the dumped waste and to advise on whether they are necessary and justified. Within the framework of IASAP, the Modelling and Dose Assessment Working Group was established to develop a predictive model for the dispersal of radioactive contaminants both within and from the Arctic Ocean and to evaluate the contributions of dominating transfer mechanisms to the dispersal and hence the risks to human health and the environment it. This report (IAEA-TECDOC-1330) summarizes the work undertaken by the Modelling and Dose Assessment Working Group between 1994 and 1996.
Download or read book Modeling the seasonal variability of a coupled Arctic ice ocean system written by S. HAKKINEN and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and implementation of a computer code for modelling the dispersion of radioactive pollutants around dumping sites written by Matjaž Četina and published by . This book was released on 1996 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 3D mathematical model LMT3D has been developed and adapted to simulate the transport and dispersion of radioactive (RA) pollutants around dumping sites. The model consists of two coupled sub-models:hydrodynmic sub-model and mass-transport submodel. The hydrodynamic sub-model is 3D, non-linear and baroclinic. A finite hybrid numerical scheme is used in a orthogonal grid to solve the basic equations. The mass-transport sub-model solves the advection-diffusion equation by a lagrangian-based particle tracking method. Several forcing factors can be occounted for in both sub-models: wind forcing,thermo-haline forcing, inflow of rivers or inflow/outflow through straits. The integrated model was applied to carry out a detailed study of transport-dispersion of RA pollutants in the Japan Sea. The report presents a description of the problem, the model and the results. A large amount of radioactive (RA) waste has been deposited in the Japan Sea at the sea bottom, at a depth of about 3500 meters. Although several measurements of RA pollution in this sea have shown no increase of radioactivity over the natural values, concern exists that there may be some leakage of the RA pollutants from the dumped waste. The question is where they might be transported by currents and dispersion, and especially after what time and where they would reach the surface layers, where they might contaminate fish and other marine organisms.
Download or read book Towards Prediction of Environmental Arctic Change written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our main objective is to use models of the coupled ice-ocean Arctic environment to understand the past and present sea ice and ocean states and to predict future scenarios of environmental change in the Arctic Ocean. To meet this objective we have developed a coupled ice-ocean model of the sea ice covered northern hemisphere at 9-km and 45-level grid. The model has been spun up for 48 years. Three 24-year experiments have been completed following the spin up, all forced with realistic 1979-2002 ECMWF data but with a different surface temperature and salinity restoring times. Results from these integrations are compared to each other and to sea ice data available over this period to address the growing need for understanding the recent warming and the subsequent decrease of the Arctic Ice Pack during the late 1990s and 2000s.
Download or read book The Development of an Ice Ocean Coupled Model for the Northern Hemisphere written by Abe Cheng and published by . This book was released on 1996-12-01 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Polar Ice Prediction System (PIPS), based on the Hibler ice model, has been reformulated into spherical coordinates for the Northern Hemisphere. These spherical coordinates help to avoid a numerical singularity at the North Pole and numerical instabilities in high latitudes. Further, a coordinate transformation was chosen so that a new equator coincides with the 170 deg W - 10 deg E great circle, and a new north pole is located at the intersection of the 100 deg E meridian and the true Equator. The spherical coordinate PIPS model has been extended southward in a version of the model called PlPS2.0. In another development, the Cox ocean model has been transformed into the same spherical coordinate system as PIPS and then coupled with the sea ice model. The coupling technique of the ice and ocean models is conceptually similar to that described in Hibler and Bryan, but the heat and momentum exchanges have been modified. The two models are coupled by exchanging daily information of ice and ocean. The coupled model has been tested using the 1986 monthly forcing of the Navy Operational Global Atmospheric Prediction System (NOGAPS), as well as other inputs describing river runoff, bottom topography, and climatological water temperature and salinity. Preliminary results have been published. This report describes the coordinate transformation referred to above, the physics of the heat and momentum exchanges, model parameters, variable ice-water drag coefficients, and a test case using the 1986 monthly NOGAPS forcing fields. For the discussions in this report, the model domain was divided into seven subregions: the Sea of Okhotsk, the Bering Sea, the central Arctic, the Barents Sea, Hudson Bay, the Labrador Sea/Baffin Bay, and the Norwegian/East Greenland Seas.
Download or read book Modeling Studies of Seasonal and Interannual Variability of Sea Ice Currents and Transports in the Arctic Ocean written by Yu Zhang and published by . This book was released on 2016 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation research, a high-resolution (up to 2 km), unstructured-grid, fully coupled Arctic sea ice-ocean Finite-Volume Community Ocean Model (AO-FVCOM) was employed to study the seasonal and interannual variability of current and sea ice in the Arctic Ocean over the period 1978-2014. The dissertation consisted of two topics. Topic 1 assessed the performance of Arctic sea ice simulation and examined the sensitivity of the model-produced bias to atmospheric forcing without any assimilation of sea ice. The simulated sea ice was in good agreement with available observed sea ice extent, concentration, drift velocity and thickness, not only in seasonal and interannual variability but also in spatial distribution. Compared with six other Arctic Ocean models, the AO-FVCOM-simulated ice thickness showed a higher correlation coefficient and a smaller residual with observations. Model-produced ice drift speed and direction errors varied with wind speed: the speed and direction errors increased and decreased as the wind speed increased, respectively. Efforts were made to examine the influences of parameterizations of air-ice external and ice-water interfacial stresses on the model-produced bias. The ice drift direction was more sensitive to air-ice drag coefficients and turning angles than the ice drift speed. Increasing or decreasing either 10% in water-ice drag coefficient or 10° in water-ice turning angle did not show a significant influence on the ice drift velocity simulation results; although the sea ice drift speed was more sensitive to these two parameters than the sea ice drift direction. Using the COARE 4.0 derived parameterization of air-water drag coefficient for wind stress did not significantly influence the ice drift velocity simulation. Topic 2 was focused on the variability of current circulation and volume transport through the Canadian Arctic Archipelago (CAA) and their relationship to basin-local atmospheric forcing. The simulated CAA outflow transport was in reasonable agreement with the flux estimated based on measurements across Davis Strait, Nares Strait, Lancaster Sound and Jones Sounds and highly correlated with the along-strait and cross-strait sea surface height (SSH) difference. Compared with the wind forcing, the sea level pressure (SLP) seemed to play a dominant role in establishing the SSH difference in the experiments. Further studies about the impact of wind and SLP on the SSH difference are needed. The change in the simulated CAA outflow transport through Davis Strait showed a negative correlation with the net flux through Fram Strait. This correlation was related to the variation of the spatial distribution and intensity of the slope current over the Beaufort Sea and Greenland shelves.
Download or read book Modelling Sea ice and Oceanic Dimethylsulfide Production and Emissions in the Arctic written by Hakase Hayashida and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent field observations suggest that the radiative forcing of aerosol and clouds in the Arctic may be seasonally regulated by the oceanic emissions of the climatically-important biogenic trace gas dimethylsulfide (DMS). However, the validity of the proposed argument is challenged by the limited spatio-temporal coverage of these earlier studies in this difficult-to-access region. In particular, little is known about the pan-Arctic distribution of the oceanic DMS emissions, its temporal variability, and the impacts of sea-ice biogeochemistry on these emissions. In this dissertation, I investigated these unexplored subjects through numerical modelling. Using a one-dimensional (1-D) column modelling framework, I developed a coupled sea ice-ocean biogeochemical model and assessed the impacts of bottom-ice algae ecosystems on the underlying pelagic ecosystems and the associated production and emissions of DMS. The model was calibrated by time-series measurements of snow and melt-pond depth, ice thickness, bottom-ice and under-ice concentrations of chlorophyll-a and dimethylsulfoniopropionate (DMSP), and under-ice irradiance obtained on the first-year landfast sea ice in Resolute Passage during May-June of 2010. Many of the model parameters for the DMSP and DMS production and removal processes were derived from recent field measurements in the Arctic, which is advantageous over the previous Arctic-focused DMS model studies as their model parameters were based on the measurements in extra-polar regions. The impacts of sea-ice biogeochemistry on the DMS production in the underlying water column and its potential emissions into the overlying atmosphere were quantified through sensitivity experiments. To extend the study domain to the pan-Arctic, I implemented the sea-ice ecosystem and the coupled sea ice-pelagic DMS cycling components of the 1-D column model into a three-dimensional (3-D) regional modelling framework. A multi-decadal model simulation was performed over the period 1969-2015 using realistic atmospheric forcing and lateral boundary conditions. The results of the simulation were evaluated by direct comparisons with available data products and reported values based on field and satellite measurements and other model simulations. The decline of Arctic sea ice was successfully simulated by the model. The magnitude of the pan-Arctic sea-ice and pelagic annual primary production and their general spatial patterns were comparable to other model studies. The mean seasonal cycle and the spatial distribution of the model-based surface seawater DMS climatology within the pan-Arctic showed some similarities with in situ measurement- and satellite-based climatologies. However, at the same time, the comparison of the DMS climatologies was challenged by the bias in the measurement-based climatology, emphasizing the need to update this data product, which was created almost a decade ago, by incorporating data acquired during the recent field campaigns. The analysis of the modelled fluxes of DMS at the ice-sea and sea-air interfaces revealed different responses to the accelerated decline of sea ice over the recent decades (1996-2015). There was no trend in the pan-Arctic ice-to-sea DMS flux due to the counteracting effect of vertical thinning and horizontal shrinking of sea ice that drove ice algal production. In contrast, the pan-Arctic sea-to-air DMS flux showed a consistent increase (about 40 % over the last two decades) driven by the reduction of sea ice cover that promoted outgassing and biological productivity. This finding suggests that the climate warming in the Arctic causes an increase in DMS emissions, and encourages further exploration of the biological climate regulation in the Arctic.
Download or read book Comparison of Advanced Arctic Ocean Model Sea Ice Fields to Satellite Derived Measurements written by David S. Dimitriou and published by . This book was released on 1998-09-01 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical models have proven integral to the study of climate dynamics. Sea ice models are critical to the improvement of general circulation models used to study the global climate. The object of this study is to evaluate a high resolution ice-ocean coupled model by comparing it to derived measurements from SMMR and SSM/I satellite observations. Utilized for this study was the NASA Goddard Space Flight (GSFC) Sea Ice Concentration Data Set from the National Snow and Ice Data Center. Using animations of side-by-side presentations, variability comparisons and anomaly values the of similarities and differences between the model and the satellite were noted. The model shows a true representation of the seasonal cycle of ice concentration variation, with natural growth, advection, decay. Model performance is weakest in the East Siberian and Laptev Seas where excessive ice is developed. A 30 day lag in the freezing and melting of ice in Hudson Bay was noted in the model. The use of monthly mean Levitus temperatures adversely affects model performance evidenced by a tendency to grow and retain excess ice in the marginal seas of the Arctic Ocean.
