Arctic

Atmospheric chemistry in the Arctic has been the subject of studies for many years, in part because of the observation of Arctic haze decades ago. This haze is composed of particles with significant amounts of sulfate, about half of which is due to long-range transport from other regions, particularly Eurasia during the winter (e.g., Barrie and Bottenheim, 1991 Polissar et al., 1998a, 1998b). 

An unusual phenomenon was reported in the Arctic in the mid-1980s. Ozone measured at ground level was observed to decrease rapidly to small concentrations, at times near zero (Bottenheim et al., 1986 Oltmans and Komhyr, 1986). As seen in Fig. 6.37, an increase in bromide ion collected on filters (f-Br) was inversely correlated with the 03 decrease (Barrie et al., 1988 Oltmans et al., 1989 Sturges et al., 1993 Lehrer et al., 1997) this could reflect either particle bromide or a sticky gas such as HBr that could be collected on the filter simultaneously. This correlation suggested that the loss of ozone was due to gas-phase chain reactions 

FIGURE 6.37 (a) Surface-level 03 at Alert, Canada, and (b) filter-collected bromide (f-Br) during an ozone depletion episode (adapted from Barrie el al., 1988). 

Subsequently, additional reactions for the chain destruction of ozone were suggested, including one involving CIO (Le Bras and Platt, 1995)  

Such chain reactions imply low NO, concentrations, which would otherwise terminate the chains by reacting with BrO and CIO to form Br0N02 and C10N02, respectively. Unless the nitrates could be recycled rapidly back to active forms of the halogens, they would terminate the chain. NO, concentrations do indeed appear to be small during O-, depletion episodes. Beine et al. (1997), for example, measured NOx 4.5 ppt during 03 depletion episodes in Norway. 

---

Specifications for density, distillation curve and viscosity shown above are for products distributed in temperate climates. Other limits are required for arctic regions, particularly the Scandinavian countries. See Tables 5.13 and 5.14. 

In Europe, the classification of diesel fuels according to cold behavior is shown in Tables 5.13 and 5.14. The products are divided into ten classes, six for temperate climates, four for arctic zones. 

European diesel fuel specifications (EN 590 Standard). Requirements for "arctic" climatic zones. 

The European specifications require a minimum cetane number of 49 for the temperate climatic zones and the French automotive manufacturers require at least 50 in their own specifications. The products distributed in France and Europe are usually in the 48-55 range. Nevertheless, in most Scandinavian countries, the cetane number is lower and can attain 45-46. This situation is taken into account in the specifications for the arctic zone (Table 5.14). In the United States and Canada, the cetane numbers for diesel fuels are most often less than 50. 

Though the type of processing required is largely dependent upon fluid composition at the wellhead, the equipment employed is significantly influenced by location whether for example the facilities are based on land or offshore, in tropical or arctic environments. Sometimes conditions are such that a process which is difficult or expensive to perform offshore can be exported to the coast and handled much more easily on land. 

Derived plant and animal products make better use or upgrade the nutritional quaHty of already existing materials or products. Synthetic and manufactured products arose from knowledge of the functional properties of food ingredients and of human and animal nutrition that involved more precise definition of nutrient requirements for growth, reproduction, lactation, and body maintenance in both humans and domestic Hvestock. Pood products have been developed to meet human needs under abnormal environments, eg, military rations for arctic, tropical, or desert environments, and special products for astronauts ia space flights. 

High strength, low alloy (HSLA) steels often contain 0.10—0.30% molybdenum. These steels exhibit toughness at low temperatures and good weldabiHty. They are used extensively for undersea pipelines (qv) transporting gas and oil from offshore weUs to pumping stations on shore, and are also used extensively in remote Arctic environments. 

The Russian icebreaker Eenin, launched ia 1959, had three 90 MWt PWRs, one of which was a spare. It operated for many years ia the Arctic Ocean. 

Second European Stratospheric Arctic Mid-Eatitide Experiment, U.K. Dept, of the Environment (London) News Release, Mar. 30,1995. 

G. Leduc and co-workers, Arctic Eand Use Research Report, AEUR, 74-75-34, Ottawa, Canada, 1976. 

Malaria affects an estimated 270 million people and causes 2—3 million deaths annually, approximately one million of which occur in children under the age of five. While primarily an affliction of the tropics and subtropics, it has occurred as far north as the Arctic Circle. The disease essentially has been eradicated in most temperate-zone countries, but some 1100 cases of malaria in U.S. citizens returning from abroad were reported to the Centers for Disease Control during 1990. Malaria is seen today in Southeast Asia, Africa, and Central and South America. It is on the increase in Afghanistan, Brazil, China, India, Mexico, the Philippines, Sri Lanka, Thailand, and Vietnam. Escalation of the disease is because of the discontinued use of the insecticide DDT which effectively kills mosquito larvae, but has been found to be toxic to Hvestock and wildlife. Also, chloroquine (6), a reUable dmg for the prophylaxis and treatment of falcipamm malaria, is ineffective in many parts of the world because of the spread of dmg-resistant strains. 

A minimum volatihty is frequently specified to assure adequate vaporization under low temperature conditions. It can be defined either by a vapor pressure measurement or by initial distillation temperature limits. Vaporization promotes engine start-up. Fuel vapor pressure assumes an important role particularly at low temperature. For example, if fuel has cooled to —40°C, as at arctic bases, the amount of vapor produced is well below the lean flammabihty limit. In this case a spark igniter must vaporize enough fuel droplets to initiate combustion. Start-up under the extreme temperature conditions of the arctic is a major constraint in converting the Air Force from volatile JP-4 to kerosene-type JP-8, the military counterpart of commercial Jet Al. 

Limestone (marble) Sandstone Granite Ice Largely CaCOj Largely SiOj Aluminium silicates H2O jbuilding foundations, construction. Arctic engineering. 

To recover oil from the continental shelf of arctic Canada and Alaska, drilling and production platforms must be built some miles offshore, in roughly 40 m of water. This is not a great depth, and would present no new problems were it not that the sea freezes in winter to a depth of around 2 m. Wind blowing across the surface of the ice sheet causes it to move at speeds up to 1 m s pressing it against the structure. Ice is... 

Winter temperatures in the arctic range between -50°C and -4°C. Expressed as a fraction of the melting point of sea ice, these correspond to the range 0.82 to 0.99 T. ... 

This is a large force - enough to demolish a structure which was merely designed to withstand large waves. Lighthouses have been lost in northern Sweden and arctic Canada in just this way. 

Chemical Designations - Syrwnyms Arctic Chloromethane Chemical Formula CH3CI. Observable Characteristics - Physical State (as shipped) Liquefied gas Color Colorless Odor Faint, sweet, non-irritating faint ether-like. 

---