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Science;ch.11
vocab
Word | Definition |
---|---|
air mass | a large body of air covering hundreds or thousands of square kilometers that has reletively uniform temp., humidity, and pressure. |
source region | a region with relatively uniform temp. and humidity where air masses form. |
warm air mass | an air mass that is warmer than the surface on which it moves |
cold air mass | an air mass that is colder than the surface on which it moves |
stationary front | a zone of contact between two disimilar air masses when neither is advancing. It usually results in no change in weather for several days. |
warm front | the advancing surface of a warm air mass as it pushes against and over a cooler air mass |
cold front | the advancing surface of a cool air mass as it moves under a warm air mass |
anticyclone | a circulation of winds around a central region of high atmospheric pressure |
mountain breeze | a breeze that is blown down a mountain into the valley |
waterspout | a tornado that occurs at sea |
cyclone | a large-scale, atmospheric wind-and-pressure system characterized by low pressure at its center |
storm surge | an abnormal rise in the level of the sea |
squall line | a line or extended narrow region within which squalls or thunderstorms occur, often several hundred miles long. |
occluded front | a composite front formed when a cold front overtakes a warm front and forces it aloft. |
monsoon | any persistent wind established between water and adjoining land. |
pressure gradient force | horrizontal force exterted on a mass of air that has a higher pressure on one side than on the other |
geostrophic wind | a wind whose velocity and direction are mathematically defined by the balanced relationship of the pressure gradient force and the Coriolis force |
jet stream | strong, generally westerly winds concentrated in a relatively narrow and shallow stream in the upper troposphere of the earth. |
valley breeze | a breeze that blows up the mountain side from a valley |
trade wind | any wind that blows in one regular course, or continually in the same direction. |
hurricane | a strong , large area cyclonic storm strong fast wind speeds |
eye | the circullar center of low pressure in a hurricane |
lightning rod | a rodlike conductor installed to divert lightning away from a structure by providing a direct path to the ground. |
land breeze | a coastal breeze blowing at night from land to sea, caused by the difference in the rate of cooling of their respective surfaces. |
polar easterlies | winds blowing constantley from northeast to west east |
forked lighting | lightning consisting of branches connected to the main stroke |
tornado | a violent , narrow, rotating, funnel shaped local windstorm |
doldrums | a belt of calms and light baffling winds |
horse latitudes | edges of the trade-wind belt, characterized by high atmospheric pressure with calms and light variable winds. |
subpolar low | a prevailing low pressure belt at approximetly 60 degrees north or south latitude |
polar high | an area of high atmoshperic pressure |
thunderstorm | a transient storm of lightning and thunder, usually with rain and gusty winds, sometimes with hail or snow, produced by cumulonimbus clouds. |
thunderhead | the upper portion of a cumulus cloud characterized by dense, sharply defined, cauliflowerlike upper parts and sometimes by great verticality. |
lighting | a brilliant electric spark discharge in the atmosphere, |
stepped leader | prior to a lightning stroke, a zig zag colum of highly ionized air |
return stroke | a faint discharge of blue light from the top of a thunderstorm cloud that propagates upward |
typhoone | what hurricanes are called in the Western Pacific and Indian Ocean regions |
storm swell | the larger than normal surface waves |
sea breeze | a thermally produced wind blowing from a cool ocean surface onto adjoining warm land. |
prevailing westerlies | The west-to-east winds that occur in the temperate zones of the Earth. |