Daily Archives March 10, 2016
The incoming energy to the earth system is in the form of solar radiation and roughly corresponds to
that of a black body at the temperature of the sun of approximately 6000 K. The sun’s emissions peak at a wavelength of approximately 0.6 mm and much of this energy is in the visible part of the electromagnetic spectrum, although some extends beyond the red into the infrared and some extends beyond the violet into the ultraviolet. As noted earlier, because of the roughly spherical shape of the earth, at any one time half the earth is in night (Fig. 1) and the average amount of energy incident on a level surface outside the atmosphere is one-fourth of the total solar irradiance or 342 Wm-2...
Although physical geographers have long included solar energy in its various manifestations in their work, only since the late 1970s have geographers actively researched renewable forms of energy. Even so, this research interest tapered off in the late 1980s, seemingly coincident with the crash in world oil prices in 1986. This hiatus was short-lived because by the early 1990s, there was renewed interest in fossil fuel scarcity, namely that of oil and gas. Geographers also began to explore the energy policy implications of the growing concern regarding global climate change, with an emphasis on energy efficiency and renewable energy development.
Although acknowledgment of the ultimate scarcity of petroleum resources dates back to the 1956 work of M...Read More
Public disinterest in nuclear power was shaken by the successful campaign to raise awareness about its purported safety risks. It was a movement that slowly gained momentum, but by 1976 an antinuclear referendum in California received ample public notice and approximately 40% of the votes. Although the referendum failed, it was a watershed for the nuclear industry because it raised many more questions than the industry could successfully answer about the safety and the financial feasibility of the technology. In addition, it prompted more restrictive and demanding siting criteria, and more than anything else it put nuclear power on the map of regular public debate...Read More
Research by geographers on the mixed effects of coal mining dates back to at least the early 1950s. Initially, this work focused on the eastern United States, but by the late 1970s and 1980s it had shifted to the arid West (along with an increasing share of the coal production). This research analyzed the potential socioeconomic impacts of ‘‘boom – town’’ development of coal or synthetic fuels. The declining economic fortunes of some of the eastern coal mining areas such as anthracite towns of Pennsylvania continued to receive attention in the 1980s. Regional input-output (IO) analysis was demonstrated to be an especially useful tool for analyzing economic effects of spatial shifts in the coal industry...Read More
Our planet orbits the sun at an average distance of 1.50 x 1011 m once per year. It receives from the sun an average radiation of 1368 Wm-2 at this distance, and this value is referred to as the total solar irradiance. It used to be called the ‘‘solar constant’’ even though it does vary by small amounts with the sunspot cycle and related changes on the sun. The earth’s shape is similar to that of an oblate spheroid, with an average radius of 6371 km. It rotates on an axis with a tilt relative to the ecliptic plane of 23.5° around the sun once per year in a slightly elliptical orbit that brings the earth closest to the sun on January 3 (called perihelion). Due to the shape of the earth, incoming solar radiation varies enormously with latitude...Read More
The siting patterns of electric power generating stations have been a major research area among energy geographers. Although early papers on this subject were published in 1960, the vast majority of these studies were done in the mid-1970s through the mid-1980s. Perhaps surprisingly, a retrospective discriminant analysis of U. S. power plant siting patterns from 1912 to 1978 showed that fuel choice was more important than regional differences in the siting process. Development of site suitability models for fossil-fueled and nuclear power plant location analysis was pioneered at the Oak Ridge National Laboratory in the late 1970s...Read More
By the early 1970s, the quantitative revolution was firmly entrenched in energy geography. Researchers began to apply several mathematical and statistical techniques to problems of spatial energy resource development and transportation, power plant siting, and socioeconomic and environmental impact analysis. These important research developments, spanning the 1970s through the mid-1990s, are discussed in turn.
Beginning in the 1970s, geographers developed and applied a variety of simulation, mathematical programming, and econometric models to oil and gas issues. Among the early work was a rather extensive analysis of North Sea oil development through 2080...Read More
KEVIN E. TRENBERTH
National Center for Atmospheric Research Boulder, Colorado, United States
El Nino The occasional warming of the tropical Pacific Ocean from the west coast of South America to the central Pacific that typically lasts approximately 1 year and alters weather patterns throughout the world.
El Nino-Southern Oscillation (ENSO) El Nino and the Southern Oscillation together; the warm phase is El Nino and the cold phase is La Nina.
enthalpy The heat content of a substance per unit mass. Used to refer to sensible heat in atmospheric science (as opposed to latent heat).
greenhouse effect The effect produced as certain atmospheric gases allow incoming solar radiation to pass through to the earth’s surface but reduce the outgoing (infrared) radiation, which is reradiated from Earth...Read More