Arctic Oscillation An atmospheric circulation pattern in which the atmospheric pressure over the polar regions varies in opposition with that over middle latitudes (about 45 degrees North) on time scales ranging from weeks to decades.
arctic climate"See polar climate.
arctic desert""Any area in the high latitudes dominated by bare rocks, ice, or snow, and having a sparse vegetation and a low annual precipitation.
Arctic Oscillation (AO) - The Arctic Oscillation is a pattern in which atmospheric pressure at polar and middle latitudes fluctuates between negative and positive phases.
Arctic Front - The boundary or front separating deep, cold arctic air from shallower, relatively less cold polar air. The overrunning of air above this boundary often provides a mechanism for lift.
ARCTIC HIGH - a very cold high pressure that originates over the Arctic Ocean.
ASOS -Automated Surface Observing System. Observes sky conditions, temperature and dewpoint, wind direction and speed, and barometric pressure.
Arctic (A) Air Mass - A bitterly cold air mass that forms over the frozen Arctic Ocean.
Arctic Sea Smoke - A dense and often extensive steam fog occurring over high-latitude ocean areas in winter.
Arid - See Desert.
Arctic Front
Front which separates cold Arctic air originating at high northern latitudes from relatively warm polar air.
Atmosphere
Gaseous envelope which surrounds the Earth.
Arctic air (a) A very cold and dry air mass that forms primarily in winter over the Arctic Basin, Greenland, and the northern interior of North America.
Arctic air—An air mass with characteristics developed mostly in winter over Arctic surfaces of ice and snow. Arctic air extends to great heights, and the surface temperatures are basically, but not always, lower than those of polar air.
Arctic Screamer: Strong, cold winds from North or Northwest, often following cold front.
ARCTIC AIR MASS
An air mass that develops around the Arctic, it is characterized by being cold from surface to great heights. The boundary of this air mass is often defined by the Arctic front, a semi-permanent, semi-continuous feature.
Arctic Circle The parallel of latitude that is approximately 66.5 degrees north of the equator and that circumscribes the northern frigid zone.
Arctic air masses are typically very shallow and have been known to produce devastating ice storms. Behind a cold front, the air mass is maritime polar (mP), but behind an Arctic front, the air mass is continental polar (cP).
Arctic Air masses form over the Arctic regions of Siberia, Greenland and North America, at about 60 degs. N. Lat. These air masses are very cold and dry, and bring very cold air over the United States as far south as the Gulf of Mexico and Florida.
Arctic sea smoke
A type of fog which is formed when cold air moves over relatively warm water.
Average Hsig ...
Arctic Air Mass
NOAA National Weather Service - Cite This Source - This Definition
Browse Related Terms: Air mass, AMS, C AMS, K AMS, WDLY
AAWU - permalink - collapse ...
Arctic Air
A mass of very dry, very cold air that develops over the snow-and-ice-covered regions of the Far North or in the southern hemisphere the far south.
Arctic front ...
Arctic Air - An air mass that originates over Canada and brings us cold temperatures.
Arctic highs, alone, rarely trigger precipitation because of the cloudless weather they produce. However, in combination with other weather-making systems, the cold air they bring can produce massive snowstorms.
Arctic front - divides cold air from extremely cold air.
Frozen precipitation
Diamond dust - fine powdery ice crystals that fall in extremely cold weather, even without clouds.
ARCTIC - Polar geographical region of Earth at latitudes greater than 66.5 degrees south. This region also experiences about 6 months of night followed by six months of day due to the Earth's tilt of 23.5 degrees.
Antarctic Front: Front that develops and persists around the Antarctic Continent, approximately between latitudes 60º and 65ºS, and separates the Antarctic Air Mass from the Maritime Polar Air Mass (Pm) further to the north.
As cold, arctic air moves down and over the United States from the colder northern regions, large bodies of water are generally warmer than the air moving over them.
Continental Arctic Air Mass - an air mass characterized by extremely cold, dry air
Continental Polar Air Mass - an air mass characterized by cold, dry air
Continental Tropical Air Mass - an air mass characterized by warm or hot dry air ...
Continental arctic air mass An air mass characterized by extremely low temperatures and very dry air.
Continental polar air mass An air mass characterized by low temperatures and dry air. Not as cold as arctic air masses.
The British Antarctic Survey first revealed the obvious decreases in ozone in the late 1970s to early 1980s. The Japanese station at Syowa also reported decreases in ozone.
When does the ozone hole occur?
Antarctic Ice Sheet See ice sheet. anthropogenic Man made. Usually used in the context of emissions that are produced as the result of human activities.
See Arctic Sea Smoke for an example. SEA ICE Ice that is formed by the freezing of sea water. It forms first as small crystals, thickens into sludge, and coagulates into sheet ice, pancake ice, or ice floes of various shapes and sizes.
When these products break down they destroy stratospheric ozone, creating the Antarctic Ozone Hole in the Southern Hemisphere spring (Northern Hemisphere autumn).
See ice-crystal haze, arctic mist.Ice GorgeIn hydrologic terms, the gorge or opening left in a jam after it has broken.Ice JamIn hydrologic terms, a stationary accumulation that restricts or blocks streamflow.
In this system, air masses are designated first according to the thermal properties of their source regions: tropical (T); polar (P); and less frequently, arctic or antarctic (A).
When arctic-origin air in winter flows southward (northward in the southern hemisphere) across (relatively) warmer seas, strong surface heating acts both to enhance the degree of instability, and trigger vigorous moist convective towers.
BELLOT WINDS Refers to the winds in the Canadian Arctic that blow through the narrow Bellot Strait between Somerset Island and the Boothia Peninsula, connecting the Gulf of Boothia and Franklin Strait.
It rises like smoke from the warm surface. The low level convection can become quite turbulent. Steam fog is most common in Arctic regions where it is called "Arctic Sea Smoke", but it can and does occur occasionally at all latitudes.
Outflow Winds - Winds that blow down fjords and inlets from the land to the sea. When cold arctic air flows from the interior of BC onto the coast, the windspeeds through mainland inlets can reach over 100 km/h.
A body of air that extends hundreds or thousands of kilometers horizontally and is relatively uniform in temperature and moisture content (see continental arctic, continental polar, continental tropical, maritime polar, ...
Ozone Hole: A depletion of stratospheric ozone that occurs over the Antarctic continent each spring.
Ice Fog - Fog composed of ice crystals instead of water droplets. Ice fog forms when clear and calm conditions prevail in extremely cold arctic air.
It is a radiational fog and the conditions for its formation are the same as for radiational fog except that the temperature must be cold. It occurs mostly in Arctic regions, but it is not unknown in middle latitudes during the cold season.
Diamond dust can also produce a range of halo effects around the sun and moon. Diamond dust forms at temperatures below -30C and is most common over the high antarctic plateau and parts of Canada and Siberia.
Not as severe as frostbite, this distress is primarily the result of the contraction in the blood vessels near the surface of the skin. The medical term used for this condition is "acrocyanosis." Perhaps in reaction to the arctic air mass this week, ...
 See also: High, Center, Antarctic, Radiation, Stratus
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