ISS test 3 - ISS test 3 The u.s. has the most severe...

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ISS test 3 The u.s. has the most severe weather of any place air masses – a large body of air that moves as a single unit and it relatively uniform in character. Can vary based on temperature, moisture content and stability. Air masses reflect the location of its source region – any body of water or land that makes a strong impression on the temperature, moisture content and stability of an air mass. Meteorologists have developed a naming convention for air masses that is based on source region. NAMING The latitudinal position of a source region relates to an air mass's temperature, while the source region's surface relates to an air mass's moisture content. For example, a high-latitude source region is very cold to cool, whereas a low-latitude source region is warm to hot. Likewise, air masses that form over ocean surfaces tend to have higher moisture contents than those that form over land. Air-masses are named using a two-letter code. The first letter is lowercase and provides information about the air mass's source region: continental (c) for those that form over land or maritime (m) for those that form over water. The second letter is uppercase and describes the latitudinal position of the source area. The most important of the latitudinal descriptors for North America are Polar (P) and Arctic (A) in high latitudes and Tropical (T) in the low latitudes. Air masses generally move north and south because of mountain ranges rather than east and west. Jet stream wind direction is always west to east along the westerlies. Cyclone- low pressure. Very large. Responsible for daily weather and precipitation. Associated with conflict of unlike air masses and once formed along the polar front, travel with the jet stream. 1. Horizontal air flow of a low pressure system is always counter clockwise in the northern hemisphere 2. At the center of low pressure, air converges and rises. Associated with stormy weather. It moves west to east and drags cold dry air from the north southward behind it and pulls warm moist air from the south northward in front of it. Warm moist air begins to cool. anticyclone - high pressure. Large cell of high pressure that migrates with the westerlies through the midlatitudes. Larger and slower than most midlatititude weather systems. It rotates in a clockwise direction. Air converges from above and sinks down through the center of the high and when it reaches the bottom it diverges out at the surface. They contain no fronts . Winds are minimal at the center but increase with distance away from the high’s center. Generally stable, dry, clear weather.
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The two fronts can feed off each other. When they pair it draws cold polar air from the north to south. Cyclogenesis –
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This note was uploaded on 04/06/2011 for the course ISS 310 online taught by Professor Arbogast during the Spring '08 term at Michigan State University.

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ISS test 3 - ISS test 3 The u.s. has the most severe...

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