Antarctica

When considering how the evolution of life could have come about, the seeding of terrestrial life by extraterrestrial bacterial spores traveling through space (panspermia) deserves mention. Much is said about the possibility of some form of life on other planets, including Mars or more distant celestial bodies. Is it possible for some remnants of bacterial life, enclosed in a protective coat of rock dust, to have traveled enormous distances, staying dormant at the extremely low temperature of space and even surviving deadly radiation The spore may be neither alive nor completely dead, and even after billions of years it could have an infinitesimal chance to reach a planet where liquid water could restart its life. Is this science fiction or a real possibility We don t know. Around the turn of the twentieth century Svante Arrhenius (Nobel Prize in chemistry 1903) developed this theory in more detail. There was much recent excitement about claimed fossil bacterial remains in a Martian meteorite recovered from Antarctica (not since... 

Rice is grown in more than 100 countries and on every continent except Antarctica. In the world economy rice is an extremely important food, second only to wheat in total world production, and its yield per hectare exceeds that of wheat (57). Rice is the main staple food for more than half of the world s population and it accounts for one-third to one-half of the daily caloric intake in many Asian countries. It is also the major source of protein for the masses of Asian people. In many African and South American countries rice is rapidly becoming the staple food for much of the population. 

Every continent, except Antarctica, grows com 40% of the present world crop is produced in the United States. In the 1987—1988 crop year, 12 states (Iowa, HI., Nebr., Minn., Ind., Ohio, Wis., Mo., S. Dak., Mich., Kans., and Tex. in order of production) produced 157.5 million metric tons (6.2 biUion bushels) that was 88% of the United States and 36% of the world s crop (66). Yield is influenced by many factors, including climate, pest control, planting density, and fertilization. Yield in the United States has increased from about 1.5 metric tons /hectare in the 1930s to about 7.5 metric tons /hectare. In 1985, a test plot produced 23.2 metric tons /hectare and yields approaching 40 metric tons /hectare are considered possible com is the most productive of the principal food crops. 

Among the rarest of all meteorites are the lunar meteorites. Isotopic, mineralogical, and compositional properties of these samples provide positive identification as lunar samples because of the unique properties of lunar materials that have been discovered by extensive analyses of lunar materials returned by the manned ApoUo and unstaffed Luna missions. AH but one of the lunar meteorites that have been found to date have been recovered from Antarctica. 

Tar sands have been reported on every continent except AustraHa and Antarctica. The best known deposits are the Athabasca of Canada, where almost 60,000 km in northeastern Alberta is underlain with an estimated 138 x 10 (870 x 10 bbl) of recoverable bitumen (157). The Alberta deposits... 

The first reactor, SM-1, was operated at Fort Belvoir, Virginia. Others were located ia Wyoming, Greenland, Alaska, and Antarctica. The fuel consisted of highly enriched uranium as the dioxide, dispersed ia stainless steel as plates or rods. Details are available ia Reference 18. 

Heterogeneous chemistry occurring on polar stratospheric cloud particles of ice and nitric acid trihydrate has been estabUshed as a dorninant factor in the aggravated seasonal depletion of o2one observed to occur over Antarctica. Preliminary attempts have been made to parameterize this chemistry and incorporate it in models to study ozone depletion over the poles (91) as well as the potential role of sulfate particles throughout the stratosphere (92). 

The Montreal Protocol of July 1987 resulted in an international treaty in which the industrialized nations agreed to halt the production of most ozone-destroying chlorofluorocarbons by the year 2000. This deadline was hastily changed to 1996, in February 1992, after a U.S. National Aeronautics and Space Administration (NASA) satellite and high-altitude sampling aircraft found levels of chlorine monoxide over North America that were 5i % greater than that measured over Antarctica. 

During the mid-1980s, each September scientists began to observe a decrease in ozone in the stratosphere over Antarctica. These observations are referred to as "ozone holes." In order to understand ozone holes, one needs to know how and why ozone is present in the earth s stratosphere. 

The discovery of ozone holes over Antarctica in the mid-1980s was strong observational evidence to support the Rowland and Molina hypothesis. The atmosphere over the south pole is complex because of the long periods of total darkness and sunlight and the presence of a polar vortex and polar stratospheric clouds. However, researchers have found evidence to support the role of CIO in the rapid depletion of stratospheric ozone over the south pole. Figure 11-3 shows the profile of ozone and CIO measured at an altitude of 18 km on an aircraft flight from southern Chile toward the south pole on September 21, 1987. One month earlier the ozone levels were fairly uniform around 2 ppm (vol). 

Fig. 11-3. Stratospheric ozone and CIO concentrations at an altitude of 18 km measured by aircraft flying south over Antarctica on September 27,1987. The dramatic decrease in ozone at a latitude of 71 degrees is attributed to the role of CIO in catalytic destruction of ozone. Adapted from Anderson et al. (13).

J. C. Farman discovered the ozone hole (substantial seasonal depletion of ozone) over Halley Bay, Antarctica. 

Thus, the mean temperature of the atmosphere, which is about 20°C at sea level, falls steadily to about —55° at an altitude of 10 km and then rises to almost 0°C at 50 km before dropping steadily again to about —90° at 90 km. Concern was expressed in 1974 that interaction of ozone with man-made chlorofluorocarbons would deplete the equilibrium concentration of ozone with potentially disastrous consequences, and this was dramatically confirmed by the discovery of a seasonally recurring ozone hole above Antarctica in 1985. A less prominent ozone hole was subsequently detected above the Arctic Ocean. The detailed physical and chemical conditions required to generate these large seasonal depletions of ozone are extremely complex but the main features have now been elucidated (see p. 848). Several accounts of various aspects of the emerging story, and of the consequent international governmental actions to... 

The report from Sheldon and co-workers was the second publication demonstrating the potential use of enzymes in ionic liquids and the first one for lipases (Entry 13) [43]. They compared the reactivity of Candida antarctica lipase in ionic liquids such as [BMIM][PFg] and [BMIM][BF4] with that in conventional organic solvents. In all cases the reaction rates were similar for all of the reactions investigated alcoholysis, ammoniolysis, and per hydrolysis. 

Coal is the most abundant and most economical fossil fuel resource in the world. Proven coal reseiwes exceed 1 trillion tons, and indicated reserves are estimated at 24 trillion tons. Coal is found in eveiy continent of the world, including Antarctica, although the largest quantities of coal are in the Northern Hemisphere. Coal is mined in some sixty countries in nineteen coal basins around the world, but more than 57 percent of the world s total recoverable reserves are estimated to be in the United States, and China, which together account for more than two-thirds of the world s coal production. 

The catalyzed decomposition of ozone is known to be responsible for the ozone hole (Figure A) that develops in Antarctica each year in September and October, at the end of winter in the Southern Hemisphere. No ozone is generated during the long, dark Antarctic winter. Meanwhile, a heterogeneous reaction occurring on clouds of ice... 

Recent research suggests that ozone depletion has affected Antarctica s climate, cooling the interior and warming the extremities. 

ICSID members are professional organizations, promotional societies, educational institutions, government bodies, companies and institutions which aim to contribute to the development of the profession of industrial design. Today ICSID consists of 149 Member Societies, representing 52 countries from all continents (except Antarctica ). These Societies collaborate to establish an international platform through which design institutions worldwide can stay in touch, share common interests and new experiences, and be heard as a powerful voice. 

Mario Molina and Sherwood Rowland used Crutzen s work and other data in 1974 to build a model of the stratosphere that explained how chlorofluorocarbons could threaten the ozone layer. In 1985, ozone levels over Antarctica were indeed found to be decreasing and had dropped to the lowest ever observed by the year 2000, the hole had reached Chile. These losses are now known to be global in extent and it has been postulated that they may be contributing to global warming in the Southern Hemisphere. 

The minimum ozone concentration over Antarctica occurs in September or October. This plot shows how the ozone concentration declined rapidly until 1999, when the phasing out of chlorofluorocarbons allowed it to stabilize. 

The stratosphere is very dry clouds do not form at lower latitudes because the temperature is not low enough. However, the stratosphere over Antarctica is distinctive the temperature can drop to below -90 Celsius during the winter and spring months, leading to the condensation of water vapor and nitric acid vapor, that is, to the formation of ice clouds (polar stratospheric clouds or PSCs). 

Several authors (8,9) suggested that PSCs could play a major role in the depletion of ozone over Antarctica by promoting the release of active chlorine from its reservoir species, mainly by the following reaction ... 

Figure 4. Ozone profiles measured in 1987 over Halley Bay, Antarctica, by Farman (20).

The catalytic cycle described earlier (reactions 8 and 9) cannot explain the rapid depletion of ozone over the South Pole, because reaction 9 requires free oxygen atoms, which are too scarce in the polar stratosphere to react at any appreciable rate with QO. Several catalytic cycles that do not require oxygen atoms have been suggested as being at work over Antarctica. 

A detailed analysis of the atmospheric measurements over Antarctica by Anderson et al. (19) indicates that the cycle comprising reactions 17 -19 (the chlorine peroxide cycle) accounts for about 75% of the observed ozone depletion, and reactions 21 - 23 account for the rest. While a clear overall picture of polar ozone depletion is emerging, much remains to be learned. For example, the physical chemistry of the acid ices that constitute polar stratospheric clouds needs to be better understood before reliable predictions can be made of future ozone depletion, particularly at northern latitudes, where the chemical changes are more subtle and occur over a larger geographical area. 

A month-long study of the effects of ultraviolet radiation (UV) on phytoplankton and ice-algae collected from Arthur Harbor, Anvers Island, Antarctica, was carried out during November-December 1987. The parameters studied included primary production rates, photosynthetic... 

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