THE FuTuRE oF NucLear Interests

Safety concerns aside, the perceived atmospheric-friendly power produced by nuclear means that the next few decades for nuclear power generation and production of uranium are solid. Approximately 30 new nuclear plants are under construction and another 200 are in the planning phase around the world. Even the nuclear reticent United States has 49 such facilities in the planning stages, the last one was approved almost 30 years ago in 1979. The resurgence of nuclear power, owing directly to rising energy costs and the global warming phenomenon, has bolstered the stocks of uranium mining companies. These operators have seen spot prices for processed uranium ore rise from $10 a pound to over $130 a pound. Uranium has become a hotter commodity than silver, gold, or steel during the early 21st century because forecast demand will rapidly escalate as new nuclear plants, added to the existing 434 facilities worldwide, are brought online.

Government interest is high in promoting nuclear power, too. As part of the Bush Administration's 2005 Energy Bill, the White House authorized the Department of Energy to achieve the following: ensure by 2050, that the United States and the rest of the world's electricity needs are met by more than 30 percent of it being driven by nuclear power, establish an effective international proliferation regime, where there are nuclear fuel states and nuclear reactor states, and reestablish the United States as the leader in nuclear energy.

The current open fuel cycle used by the United States for its 103 nuclear power plants creates a massive problematic waste stream. If the United States started to store spent nuclear fuel at Yucca Mountain, the proposed U.S. Department of Energy storage facility for spent radioactive waste, it would immediately fill the facility. The challenge is to shift the process from an open to a closed fuel cycle. If not, 10 Yucca Mountain nuclear storage facilities would have to be built, with 10 times the space avail able at Yucca to store nuclear materials. With this in mind, the move to a closed fuel cycle will likely be made, and a smaller, cooler nuclear waste stream could result. The nuclear industry is pressing for this outcome, as well as for the use of Yucca Mountain as soon as possible.

It appears the U.S. government is on a fast track to implement strategies that make nuclear research, development, and deployment happen. This quest is reminiscent of the Space Race of the 1960s, when the United States sought to overtake the Soviets. Nuclear power in the eyes of the public has gone from the status of a pariah to a savior. Industry and government policy reinforces this perception. By looking at nuclear power plants through green-colored glasses, many see the reactor's performance of producing greenhouse gases at an outstanding level of zero. Without the glasses, those viewing the entire nuclear cycle see it as a contributor to global warming and the depletion of the world's uranium stocks as another example of unsustainable behavior.

SEE ALSo: Alternative Energy, Overview; Automobiles; Climatic Data, Atmospheric Observations; International Institute for Sustainable Development (IISD).

BIBLIOGRAphY. R.L. Garwin and Georges Charpak, Megawatts and Megatons: A Turning Point in the Nuclear Age (New York, 2001); IEEE Panel Discussion on the State of Nuclear Energy, with Dr. Dave McCallen and Dr. Jasmina Vujic, (March 28, 2006); R.K. Koslowsky, A World Perspective through 21st Century Eyes (Victoria, 2004); Press Democrat, "Radioactive Spill from Japan Quake," www.press-democrat.com (cited July 2007); San Francisco Chronicle, "PG&E Looking at Nuclear Plants," www.sfgate.com (cited November 2006); Lynda Williams, "Nuclear Power: Is it Green, Cheap, & Safe?" SRJC lecture (April 26, 2006).

Robert Karl Koslowsky Independent Scholar

Ocean Component of Models

CLIMATE MODELs ARE computer simulations representing the Earth in layers and boxes. These models use complex mathematical equations to determine future climate possibilities based on parameters of baseline conditions and changing variables, like increased greenhouse gases, and rising temperature. The equations in the separate cells are used to mathematically calculate numerous conditions including the flow of heat, moisture, sunlight, wind, and the condition of the adjacent cells. Early climate models provided uncertain projections because the equations failed to include the dynamics of the little-understood ocean circulation. Two-thirds of the Earth is covered by ocean, which acts as a heat reservoir and a heat transport system; changes in the ocean can cause widespread changes in climate. Every few years, a warming of the eastern Pacific near the equator creates El NiƱo conditions, altering rainfall and temperature patterns.

The ocean plays a central role in climate variability, modifying the flux of heat into the atmosphere, stimulating changes in the atmospheric circulation, which, in turn, modify the general circulation of the ocean. Studies of annually-averaged air-sea heat exchange have shown that a large transfer of heat from the ocean to the atmosphere occurs downstream from the subtropical western boundary currents.

examples of models with ocean components

The addition of ocean circulation to climate models is the result of numerous studies that determined the circulation patterns of the ocean with fluid motion. These include the World Ocean Circulation Experiment, with nine years (1990-98) of observations (physical, chemical, and satellite), by approximately 30 nations to determine the baseline conditions for assessing future climate change. The second phase of the World Ocean Circulation experiment was Analysis, Interpretation, Modeling, and Synthesis, ending in 2002. Sophisticated numerical ocean models were also developed to provide a framework for the interpretation of the observations and for the prediction of the future ocean state.

The World Climate Research Programme is studying climate variability and predictability (CLIVAR), with research focusing on interactions between the ocean and the atmosphere and collaboration with companion research projects to study the role of the land surface, snow, ice, and stratospheric processes in climate.

The Global Ocean Data Assimilation Experiment (GODAE) began in 1997, to develop better ocean observations and ocean forecasts utilizing improved technology (in-situ and remote) to observe, measure, model, and assimilate data available worldwide to researchers needing comprehensive ocean and marine data and forecasts.

The Argo project, begun in 2000, deploys 3,000 profiling floats (spaced approximately 3 degrees apart throughout the world's oceans) to collect temperature, velocity, and salinity measurements on the physical state of the upper ocean, with emphasis on seasonal and decadal variability. The collected data will be used for initializing ocean and coupled ocean-atmosphere forecast models, data assimilation, and model testing.

With increasing data on ocean physics, chemistry, and biology, improved models are being created, incorporating the ocean component into computer models, and using more complex computing systems. The Parallel Ocean Program is a publicly available model developed at Los Alamos National Laboratories, using ocean circulation with depth as the vertical coordinate. Researchers, in adapting the Parallel Ocean Program for parallel computers to improve performance, also enhanced the model's physical representation of the real ocean. Higher resolution simulations have shown greater agreement with observations of sea-surface height variability in the Gulf Stream.

The Open Ocean Slab model includes sea ice in its component for figuring the ocean component mixed-layer temperature, including density of ocean water, heat capacity of ocean water, annual mean ocean mixed-layer depth, fraction of the ocean covered by sea ice, net atmosphere to ocean heat flux, internal ocean mixed-layer heat flux, simulating deep water heat exchange and ocean transport, heat exchanged with the sea ice (including solar radiation transmitted through the ice, and heat gained when sea ice grows over open water). The resulting mixed-layer depths in the tropics are generally shallow, while at high latitudes, in both hemispheres, there are large seasonal variations.

The Hadley Center Ocean Carbon Cycle (HadOCC) model includes ocean biology to provide a more accurate estimate of the chemical reactions of carbon dioxide in the surface waters, and for carbon dioxide entering at the surface to reach deep ocean waters. By using a reduced resolution from versions used for climate prediction, the model allows for greater testing of the carbon cycle, though it does show less accuracy in representing ocean physics. The model uses a simplified biological system, using only phytoplankton (nutrient and waste products). Dissolved inorganic carbon is taken up by phytoplankton growth and returned with biological breakdown. The model tracks the amount of carbon in dissolved inorganic carbon and in the four biological components. Even with the multiple simplifications in the model, the correlation with ocean observations for both Atlantic and Pacific models is good. The model does vary widely with observation at the equator, with the model showing excess surfacing of deep-water rich in carbon and releasing that carbon into the atmosphere.

The numerous complexities of interactions and the increasing ability to include these interactions in computer models provides a better picture of climate change possibilities, while maintaining the limitation of including so many real-life variables in a simulation.

sEE ALsO: Climate Models; Computer Models; Oceanic Changes; Oceanography; Wind-Driven Circulation.

BIBLIOGRApHY. Global Ocean Data Assimilation Experiment, www.godae.org (cited November 2007); Hadley Center, www.metoffice.gov.uk (cited November 2007); Los Alamos National Laboratory, "The Parallel Ocean Program (POP)," www.climate.lanl.gov (cited November 2007); National Oceanography Centre, "The World Ocean Circulation Experiment (WOCE) 1990-2002," www.noc. ac.uk (cited November 2007); World Climate Research Programme, www.clivar.org (cited November 2007).

Lyn Michaud Independent Scholar

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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