Aerosol 1: A small droplet or particle suspended in the atmosphere, typically containing sulfur. Aerosols are emitted naturally (e.g., in volcanic eruptions) and as the result of human activities (e.g., by burning fossil fuels).
Aerosol 2: A product that relies on a pressurized gas to propel substances out of a container. Traditional propellants included CFC-11 and HCFC-22, while today's aerosols use hydrocarbons and compressed gases.
Amphipods: A taxonomic group of animals belonging to the phylum Arthropoda and the Class Crustacea. They are animals that show a flattening of the body laterally (as opposed to dorso-ventrally (top to bottom) like slaters) including sand hoppers.
Antarctic Convergence: An area in the southern ocean where warmer northern waters meet coold Antarctic waters. This temperature difference effectively isolates life in the southern ocean.
Auroras: A phenomena of moving streams or curtains of light, caused by interactions of charged particles from the sun with the outer fringes of the earth's atmosphere.
Air Pressure: The total weight of air above a specific point. The unit of measure is the millibar (mb) or hecto pascal (hp). Atmospheric (air) pressure is highest at the earth's surface. Air masses are never at exactly the same pressure. An area of low pressure is known as a depression. An area of high pressure is known as an anticyclone. Increasing air pressure usually indicates an improving weather situation with calm conditions likely.
Anemometer: An instrument used to measure wind speed.
Aneroid barometer: An instrument used to measure air pressure through the expansion and contraction of a sealed metal chamber which has been partially emptied of air.
Anticyclone or High: An area of high pressure air surrounded by a clockwise pattern of wind in the southern Hemisphere and an anticlockwise pattern of wind in the Northern Hemispher.
Atmosphere: The envelope of gases surrounding the earth. The upper limit of earth's atosphere is difficult to determine but, conventionally, it is regarded as occurring at 1,000 kilometres above sea level.
Beaufort Scale: In 1805, Sir Francis Beaufort developed a scale used to measure wind force. The scale ranges from 0 (calm) to 12 (hurricane force).
Biotic: Factors of the environment due to living things eg predation, food supply, competition.
Blizzard: A combination of strong wind and blowing or fallen snow.
Blubber: A layer of fat under the skin and over the muscles which protects an animal from cold; can be eaten by humans.
Calve: The word used to describe the breaking off of ice from ice shelves (eg the Ross Ice Shelf) to form icebergs.
Cirrus: High altitude cloud (6,000 to 12,000m) composed of ice crystals with a delicate and whispy appearance.
Centrigrade (C): A temperature scale
in which the melting point of water is 0 degrees and the boiling point
is 100 degrees C. 100 degrees C is equal to 212 degrees Fahrenheit. To convert Fahrenheit
to Centigrade: C degrees x9/5+32.
Russian researchers at the Vostok Base, Antarctica report the lowest temperature found on Earth, -128.6 degrees Fahrenheit (89.2 C).
Chlorofluorocarbon (CFC): A compound consisting of chlorine, fluorine, and carbon. CFCs are very stable in the troposphere. They are broken down by strong ultraviolet light in the stratosphere and release chlorine atoms that then deplete ozone. Commonly used as refrigerants, solvents, and foam blowing agents. The most common CFCs are CFC-11, CFC-12, CFC-113, CFC-114, and CFC-115.
Cloud: When water vapour in the air condenses as a mass of air rises and cools, clouds are formed. Clouds consist of water droplets and ice crystals. Cloud cover is usually measured in eighths. eg 4/8ths is half the sky covered in cloud.
Coriolis Force: Earth's rotation from east to west exerts a dragging force on the atmosphere. This "coriolis"force is greater near the poles, where earth's surface spins faster, than at the equator, where the surface moves comparatively slowly.
Crevasse: The deep cracks in ice caused by ice movement.
Cumulus: A type of cloud form with massive or globular appearance.
Cyclone: An area of low pressure around which strong winds circulate clockwise I the southern hemisphere and anticlockwise in the northern hemisphere.
Dehydrated: Dried out. Usually referred to food that has had most of its water removed for preservation. See Freeze Dried
Depression:Sometimes called a low; an area of low pressure around which wind circulates in a clockwise direction in the Southern Hemisphere. (see also cyclone).
Dobson Unit (DU): A measurement of ozone levels. If 100 DU of ozone were brought to the Earth's surface, it would form a layer 1 millimeter thick. In the tropics, ozone levels are typically between 250 and 300 DU year-round. In temperate regions, seasonal variations can produce large swings in ozone levels. For instance, measurements in Leningrad have recorded ozone levels as high as 475 DU and as low as 300 DU. These variations occur even in the absence of ozone depletion, but they are well understood. Ozone depletion refers to reductions in ozone below normal levels after accounting for seasonal cycles and other natural effects.
DNA: Deoxyribosenucleic acid. The stuff that gives life its characteristics. Found in the nuclei of all our cells and in viruses and bacteria etc.
Dry Valleys: That area of the Antarctic continent in Victoria Land close to the coast where the glaciated valleys are ice free. The Dry Valleys were formed by the uplift of the Transantarctic Mountains being faster than the glaciers were able to cut there way through to the coast. The glaciers then became trapped behind the lip of rock at the head of the valleys. Dry winds blowing down from the polar plateau to the coast have kept the valleys ice free for over 2 million years.
Ecosystem: A biological community of plants and animals and the physical environment around the community. Ecosystems can be large eg the earths biosphere or small eg a cow pat. Ecosystems are usually named after the most dominant feature; eg temperate rainforest ecosystem, Southern Ocean ecosystem.
Electromagnetic spectrum:The range of frequencies of radiation having electrical and magnetic characteristics. The spectrum includes radio waves at one end with the longest wave lengths, then infra red, visible light, ultra violet, x-rays, gamma rays and finally cosmic rays with the shortest wavelengths.
Fahrenheit: A temperature scale in which the melting point of water is 32 degrees and the boiling point is 212 degrees F. 32 degrees F is equal to 0 degrees Centigrade. One Fahrenheit degree is 5/9ths of a Centigrade degree. To convert Fahrenheit degrees into Centigrade: F degrees-32x5/9.
Firn: An intermediate stage in the conversion of snow to ice through accumulation
Fossil: The remains of something previously living which has been preserved in the ground or ice.
Freeze dried food: Food that has been dried (dehydrated) by evaporation of ice in a vacuum.
Front: Fronts are boundaries between masses of warm and cold air in a depression.
Frostbite: An inflammation of the skin, especially of the feet, face and hands, caused by exposure to extreme cold.
Glaciology: A study of the formation, movement and evolution of ice.
GIS: Geographical Information Systems; a system for storing, analysing and presenting spatial data in digital form. GIS uses computers to reassemble data about geographical and other spatial data eg land use, demographic data etc.
Glacier: A glacier is any natural accumulation of ice that moves. Glaciers are ofen described as rivers of ice. The Antarctic is covered by one large ice sheet that moves - under the influence of gravity - toward the coastline (much like icing flowing off the top of a cake). Near the coast the ice sheet divides into smaller rivers of ice - glaciers - that in most cases flow into ice shelves, the permanent floating slabs of ice that fringe 45% of the coastline.The largest glacier in the world is the Lambert Glacier. This glacier drains an area of over 1 million square kilometres of East Antarctica, flowing through the Prince Charles Mountains into the Amery Ice Shelf. The glacier is 400 km long and over 40km wide and the ice shelf adds another 300km to its length. On average 35 cubic kilometres of ice a year flows down the glacier and breaks off as ice bergs from the ice front which is 200 km wide where it meets the sea. The glacier moves at around 230 metres a year through the mountains but a fast 1km a year at the ice shelf.
Global Warming Potential: A number that refers to the amount of global warming caused by a substance. The GWP is the ratio of the warming caused by a substance to the warming caused by a similar mass of carbon dioxide. Thus, the GWP of CO2 is defined to be 1.0 . CFC-12 has a GWP of 8,500, while CFC-11 has a GWP of 5,000. Various HCFCs and HFCs have GWPs ranging from 93 to 12,100. Water, a substitute in numerous end-uses, has a GWP of 0.
Gondwana: A super-continent situated in the southern hemisphere that contained Antarctica, South America, Africa, Australia, India and New Zealand. About 160 million years ago Gondwana began to break up and the individual land masses moved to their current positions.
GPS: The Global Positioning system- a system for fixing one's position on the eareth's surface using a computer which calculates inputs from several satellite signals.
Greenhouse effect: The heating of the earth's atmosphere caused by the increased levels of carbon dioxide, which prevents the escape of reflected solar energy.
Greenhouse gases: The gases that together produce the Greenhouse effect. They include carbon dioxide, methane and water vapour.
Hagglund: The Swedish over-snow vehicle used at New Zealand's Scott Base.
Halon: A compound consisting of bromine, fluorine, and carbon. The halons are used as fire extinguishing agents, both in built-in systems and in handheld portable fire extinguishers. Halon production in the U.S. ended on 12/31/93 because they contribute to ozone depletion. They cause ozone depletion because they contain bromine.
Hydrochlorofluorocarbon (HCFC): A compound consisting of hydrogen, chlorine, fluorine, and carbon. The HCFCs are one class of chemicals being used to replace the CFCs. They contain chlorine and thus deplete stratospheric ozone, but to a much lesser extent than CFCs. HCFCs have ODPs ranging from 0.014 to 0.11. Production of HCFCs with the highest ODPs will be phased out first, followed by other HCFCs.
Hydrofluorocarbon (HFC): A compound consisting of hydrogen, fluorine, and carbon. The HFCs are a class of replacements for CFCs. Because they do not contain chlorine or bromine, they do not deplete the ozone layer and have an ODP of 0. Some HFCs have high GWPs.
Hydroponics: A method of growing plants without the use of soil. The nutrients that the plant would normally extract from the soil is provided in (a warm) solution
Hypothermia: The reduction in temperature of the body core to below 35C. Occurs as a result of exposure to extreme cold.
Iceberg: An iceberg is a large chunk of ice that has broken off an ice shelf or glacier.
Ice Shelf: Floating ice 200 to 1300m thick, that form from the coalescing of glaciers. Ice also forms on the underside of ice shelves to increase their thickness. The Ross Ice Shelf covers an area of 508,000 square kilometres - an area equal to the size of France.
The 20,000 year-old expanse of Antarctic ice known as the Larsen Ice Shelf has developed a crack 65 km long. This, combined with the separation of a large iceberg with a surface area of around 2,900 km and a thickness of 200 meters (now making its way north), will require the drafting of new maps of Antarctica. Both changes have been attributed to global warming. (SOURCE: Econet)
Immune system: The system in organisms which resists and overcomes infection.
International Geophysical Year (IGY): Following on from previous international polar research programmes The International Council for Scientific Unions agreed to coordinate a research programme with special emphasis on meteorology, oceanography and geomagnetism in Antarctica during 1957-58.
Twelve nations set up 50 stations with a total of 5,000 scientists and support staff to carry out the research programmes. America established the Amundsen-Scott station at the South Pole and Russia set up Vostok station at the Pole of Inaccessibility, the
point on the continent furthest from all its coasts. The stations were all linked by radio. One important achievement of the IGY was the crossing of the Antarctic continent by Sir Vivian Fuchs from the Weddell Sea to the Ross Sea by Sno-cats.
Sir Edmund Hillary from New Zealand reached the South Pole by Fergusson farm tractors in support of the crossing.
The IGY was so successful in Antarctica that the Scientific Committee on Antarctic Research (SCAR) was set up to continue its work.
Isobars: Lines on a weather map that join places of equal atmospheric air pressures. They often look like whirl pools which tell us where there are low and high air pressure areas.
Jet stream: A tube-like flow of air moving horizontally at very high speed at about 12 kilometres above the earth's surface.
Katabatic winds: An air mass which moves from the interior to the coast, down the slope under the inflence of gravity.
Knot: A knot is a unit of speed and is equal to 1 nautical mile (see below) per hour. (multiply by 1.85 to convert to km/h).
Krill: Small shrimp like creatures that exist in huge numbers in the southern ocean and provide. a vital link in Antarctic food chains between producers (plants) and herbivores.
Latitude (lines of): Imaginary lines that pass around the earth parallel to the equator. The equator itself is latitude 0 degrees while the geographic poles are latitude 90 degrees.
Lenticular hogsback: Clouds that form at the crests of waves of wind. Sometimes called hogsbacks and often indicative of approaching bad weather.
Lichen: Organisms made up of algae living in the threads of a fungus. The algal cells benefit from the protection and water-retaining properties of the fungus; the fungus benefits from being able to share the food made by the photosynthesising algal cells.
Longitude (lines of): Imaginary lines (great circles) that pass around the earth intersecting at the north and south geographic poles. Lines of longitude are numbered from 0 degrees - called the greenwich meridian - to 180 degrees. Lines of longitude are designated as E or W depending on whether they are east or west of the Greenwich Meridan. Scott Base is about 168 degrees east.
Magnetometry: A study of magnetic fields, particularly the magnetic field of the earth.
Manhauling: The pulling of sledges by people on a journey eg .
Metamorphic Rock: Rock that has been changed by the action of heat and pressure.
Meteorite: A fragment of rock which has reached the earth from outer space.
Meteorology: The study of the atmosphere, especially for weather forecasting.
Methyl Bromide: A compound consisting of carbon, hydrogen, and bromine. Methyl Bromide's chemical formula is CH3BR. An effective pesticide, this compound is used to fumigate soil and many agricultural products. Because it contains bromine, it depletes stratospheric ozone and has an ODP of 0.6. Production of methyl bromide will end in the U.S. on 12/31/2000.
Millibar (Mb): Unit of atmospheric pressure equal to 100 newtons (N) per square metre, or 100 pascals (Pa).
Montreal Protocol: The treaty governing stratospheric ozone protection and research. The Montreal Protocol, signed in 1987, governs the end of production of ozone-depleting substances. Under the Protocol, various research groups continue to assess the ozone layer through a series of reports. In addition, the Multilateral Fund provides resources to developing nations to promote the transition to ozone-safe technologies.
Nanometer: A distance of one billionth of a meter. The nanometer, or nm, is a common unit used to describe wavelengths of light or other electromagnetic radiation such as UV. For example, green light has wavelengths of about 500-550 nm, while violet light has wavelengths of about 400-450 nm. One billionth is a tiny number; 48 round-trips between Los Angeles and Washington, DC is roughly one billion feet.
Nautical mile: The distance between each minute of latitude (about 1.85km). There are 60 nautical miles to one degree of latitude.
NIWA: Acronym for the National Institute of Water and Atmospheric research Ltd.
Ozone: A bluish gas, very chemically
active that is made up of three atoms of oxygen. Present in the
atmosphere at altitudes of 15 to 30 kilometres. Nearly 90% of the Earth's ozone is in the stratosphere and is referred to as the ozone layer
"Ozone depletion" means more than just the natural destruction of ozone, it means that ozone loss is exceeding ozone creation.
Ozone-Depleting Substance(s) (ODS): A compound that contributes to stratospheric ozone depletion. ODS include CFCs, HCFCs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform. ODS are generally very stable in the troposphere and only degrade under intense ultraviolet light in the stratosphere. When they break down, they release chlorine or bromine atoms, which then deplete ozone.
Ozone Depletion Potential: A number that refers to the amount of ozone depletion caused by a substance. The ODP is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of CFC-11. Thus, the ODP of CFC-11 is defined to be 1.0. Other CFCs and HCFCs have ODPs that range from 0.016 to 1.0. The halons have ODPs ranging up to 10. HFCs have zero ODP because they do not contain chlorine.
Ozone layer: The region of the stratosphere containing the bulk of atmospheric ozone. The ozone layer lies approximately 15-40 kilometers (10-25 miles) above the Earth's surface, in the stratosphere. Depletion of this layer by ODS will lead to higher UVB levels, which in turn will cause increased skin cancers and cataracts and potential damage to some marine organisms, plants, and plastics.
Pascal (Pa): Unit of atmospheric pressure equal to one hundredth of a millibar. One hecto pascal (hp) = 1 millibar.
Pelagic fish: Fish that live in the upper levels of the water column nearer the water surface.
Pemmican: Dried lean meat pounded into a paste with melted fat and pressed into cakes; used as field rations by early expeditions.
Phytoplankton: Microscope plant life (unicellular algae) that lives in the sea. Phytoplankton provide the majority of plant life which Antarctic food chains depend on.
Plate tectonics: The mechanism of continental drift, by which continents move very slowly towards or away from each other, carried on "plates" floating on the earth's molten core.
Polar vortex: A low depression system caused by strong westerly winds that remains stationary over the south pole.
Polynyas: Areas of open water in pack ice.
Propellant: An explosive substance used to fill spray cans; commonly hydrocarbons or chloroflurocarbons.
Protozoan parasites: Parasites belonging to the protozoa group. These are primitive single celled animals
Rookery: A rookery is a colony of penguins (or seals). Male emperor penguins huddle together in a rookery incubating their eggs on their feet. In so doing they reduce the heat loss from their bodies by up to 50%.
Sastrugi: Wind-blown ridges on the surface of hard snow. May reach up to a metre in height.
Scurvy: A disease caused by a deficiency in vitamin C resulting from a lack of fresh fruit and vegetables in the diet.
Sea Ice: The ice formed from sea water that has frozen during the onset of winter. Sea ice surrounds the Antarctic continent during winter reaching its maximum extent in September when it covers 20 million square kilometres. It recedes to a minimum in February of about 4 million square kilometres. The ice thickens rapidly during May and June by the freezing of water underneath and the addition of snow on the surface. In midwinter the ice can reach thicknesses of 3-4 metres. Sea ice can vary in density (or concentration). Sometimes there may be large areas of open water called polynas, within the sea ice flows (pack ice).
Seismic survey: The science of calculating the thickness of an area
Skidoo: Sometimes called motor toboggans or tin dogs. Skidoos are tracked personel carriers for one or two people used on snow or ice. They handle soft snow very effectively and are often used for towing sledges.
Solar radiation: Energy from the sun in the form of electromagnetic waves.
Solvent: A substance usually a liquid that dissolves other substances (called the solute).eg in a solution of water and sugar water is the solvent, sugar is the solute.
Spectrograph: An instrument for photographing spectra eg the electromagnetic spectrum.
SBUV/2: The Solar Backscatter Ultraviolet instrument measures the daily total column of ozone from onboard the NOAA-11 and NOAA-9 satellites.. Maps are made from this data.
Spectrometer: An instrument for measuring spectra eg the electromagnetic spectrum. Sometimes called a Ozone Hole-Ometer??
The ozone spectrophotometer (a device that compares wavelengths of light) that first alerted scientists to the ozone hole over Antarctica in the early 1980's, has changed very little since its invention by Gordon Dobson in 1927. (SOURCE: The Irish Times )
Stratosphere: The layer of atmospheric air above the troposhere.. The stratosphere extends from about 10km to about 50km in altitude. Commercial airlines fly in the lower stratosphere. The stratosphere gets warmer at higher altitudes. In fact, this warming is caused by ozone absorbing ultraviolet radiation. Warm air remains in the upper stratosphere, and cool air remains lower, so there is much less vertical mixing in this region than in the troposphere.
Swim bladder: An organ found in most fish that traps a bubble of air to enable the fish to maintain buoyancy. It is an extension of the oesophagus.
Temperate: An area of the globe north and south of the equator between the arctic circle (60 degrees north)and the tropic of cancer (23 degrees north) and the Antarctic circle (60 degrees south) and the tropic of capricorn (23 degrees soiuth).
TOMS: The Total Ozone Mapping Spectrometer (TOMS) instrument, is managed by The Goddard Space Flight Center (NASA). From satellites such as Nimbus-7 it makes measurements of the total ozone in a column of air (from ground to space). By making 14 polar orbits each day, this single instrument provides daily maps of ozone covering most of the globe. With just the one instrument circling around and around, the problems of calibration differences between sites are very much reduced. With the abundance of global data, one can calculate statistics on ozone changes that are reliable and robust. As of this writing, there are no TOMS instruments measuring ozone. Designed to last about two years, the first TOMS, which flew on board the Nimbus 7 spacecraft (at an altitude of about 950 km), began operations in November 1978 and lasted until May 1993. The second TOMS instrument was launched in August 1991 aboard the Russian Meteor-3 spacecraft (at about 1205 km altitude); it failed in December 1994.
Toxins: Any poisonous substance produced by animals or plants.
Transantarctic mountains: A chain of mountains in the Antarctic that began to rise about 65 million years ago. They stretch from the edge of the Ross Sea at a point 70 degrees south and 165 degrees east across to 85 south and 90 degrees west.
Troposphere: The lowest part of the atmosphere. The troposphere extends from the surface up to about 10 km in altitude, although this height varies with latitude. Almost all weather takes place in the troposphere. Mt. Everest, the highest mountain on Earth, is only 8.8 km high. Temperatures decrease with altitude in the troposphere. As warm air rises it cools, falling back to Earth. This process, known as convection, means there are huge air movements that mix the troposphere very efficiently.
UV: Ultraviolet radiation. Ultraviolet radiation is a portion of the electromagnetic spectrum below visible light. The sun produces UV, which is commonly split into three bands: UVA, UVB, and UVC. UVA is not absorbed by ozone. UVB is mostly absorbed by ozone, although some reaches the Earth. UVC is completely absorbed by ozone.
Windchill: The cooling effect of wind and low temperature.