Air mass
Weather is the result of movement and interaction in air masses in the atmosphere. Air mass is a large body of air that has fairly uniformed physical properties, such as temperature and moisture content, at any given altitude. An air mass forms when a large body of air becomes fairly stationary over a region of Earth’s surface or as air moves over a large uniform region like an ocean. The air is strongly influenced by the properties of the region. An air mass formed over water contains more water vapor than one on land. The air mass on the pole is colder than from the tropics. Air masses are classified by whether they form on land or sea, and the latitude. A maritime air mass forms over water and continental air mass forms over land. If the air mass forms 50 degrees north and south latitude in the cold pole it is called the polar air mass. If an air mass forms in the warm tropics it is called the tropic air mass.
Maritime polar air mass form in the North Pacific and North Atlantic ocean. They are cool and moist and has heavy precipitation in coastal areas. Continental polar air mass form over northern Canada and brings cold dry air to central east US. Maritime tropical air mass originate in the Gulf of Mexico and warm oceans in south. Continental tropical air mass form in Northern Mexico and dry areas in south west. They bring hot dry air from great plain.
Air masses move with the circulation of air throughout the world. The convection currents move the warm air in the equator to the pole and cold air in the pole to the equator. Air mass collides in the middle latitudes. As an air mass moves, it tends to retain the properties of the region where it formed. When such different air mass meet, they don't mix, but instead boundary forms between them.
Maritime polar air mass form in the North Pacific and North Atlantic ocean. They are cool and moist and has heavy precipitation in coastal areas. Continental polar air mass form over northern Canada and brings cold dry air to central east US. Maritime tropical air mass originate in the Gulf of Mexico and warm oceans in south. Continental tropical air mass form in Northern Mexico and dry areas in south west. They bring hot dry air from great plain.
Air masses move with the circulation of air throughout the world. The convection currents move the warm air in the equator to the pole and cold air in the pole to the equator. Air mass collides in the middle latitudes. As an air mass moves, it tends to retain the properties of the region where it formed. When such different air mass meet, they don't mix, but instead boundary forms between them.
Warm and Cold Fronts |
FrontsThe sharply defined boundary that forms when two unlike air masses meet is called front. When continental polar air mass collides with maritime tropical air mass, clouds and precipitation often accompany fronts. There are 4 types of fronts: cold fronts, warm fronts, stationary fronts, and occluded front.
Cold front Cold front occurs when a cold air mass overtakes a warm air mass. Since cold air is denser than warm air, the cold air mass remains close to the ground and moves underneath warm air mass. Cold fronts move quickly and steep so the warm air mass rapidly rises. The rapid rise causes cumulus and cumulonimbus clouds. Strong wind, thunder storms, and large amount of precipitation occurs in cold fronts. But since the cold front is steep the duration is short. Warm fronts Warm fronts occurs when a warm air mass overtakes cold air mass. Since the cold air is denser, it remains close to the ground. The warm air mass rises up over the cold air mass gradually, so the Warm front is not very steep. When warm air rises, stratus clouds form and if the air mass has a lot of moisture, heavy rain and thunderstorms occur. Stationary fronts Sometimes when 2 air masses converge, neither air masses overruns the other. Stationary fronts occur when 2 unlike air masses have formed a boundary but neither of them moves. Stationary front results in clouds and steady rain or snow. Occluded front Occluded front forms when warm air mass is caught between 2 cooler air masses. Cold air masses force the warm air mass to rise, trapping in between the 2 cold air mass. As the warm air rises and cools, water vapor condenses which causes cloudy sky and precipitation. |
Cyclons
Cyclons are weather systems with a center of low air pressure. Cyclons circulate Counter clockwise on the Northern hemisphere and Clockwise on South. Since air moves from high to low pressure, air spins towards the center. Cyclones are associated with clouds, precipitation, and stormy weather. Air is converging so fronts develop. Cyclons move with the global wind.
Air cyclones are weather systems with high air pressure in the center, so air flows away from the center.Weather associated with an anticyclone includes clear skies, very little precipitation, and generally calm conditions.
Air cyclones are weather systems with high air pressure in the center, so air flows away from the center.Weather associated with an anticyclone includes clear skies, very little precipitation, and generally calm conditions.
Storm and Tornado
Major types of storms are thunderstorm, tornadoes, and tropical storms (hurricanes)
Thunderstorm is a small weather system that includes thunder and lightning. Thunderstorms form when columns of air rise within a cumulonimbus cloud. Cold fronts lift the warm air up resulting thunderstorms, also when the rising air is cooled to dew point. Lightning is a sudden electrical discharge in the atmosphere. Positive charges develop in the top of the cloud and negative charge on the base. Thunder is a sound produced by rapidly expanding air along the path of a lightning discharge. When lightning occurs, it heats the surrounding air and produces sound.
Twister is a common name for a tornado, a small intense windstorm that forms a rotating column of air. Tornadoes occur on cold front or thunderstorm where the center has low pressure. Tornado forms when a vertical cylinder of rotating air develops in a thunderstorm.To form there needs to be great difference between the properties of colliding air masses.
Thunderstorms and tornadoes often associated with cyclone of the middle latitudes.
Hurricane is a large tropical cyclone with winds at least 119 kilometres per hour.
Thunderstorm is a small weather system that includes thunder and lightning. Thunderstorms form when columns of air rise within a cumulonimbus cloud. Cold fronts lift the warm air up resulting thunderstorms, also when the rising air is cooled to dew point. Lightning is a sudden electrical discharge in the atmosphere. Positive charges develop in the top of the cloud and negative charge on the base. Thunder is a sound produced by rapidly expanding air along the path of a lightning discharge. When lightning occurs, it heats the surrounding air and produces sound.
Twister is a common name for a tornado, a small intense windstorm that forms a rotating column of air. Tornadoes occur on cold front or thunderstorm where the center has low pressure. Tornado forms when a vertical cylinder of rotating air develops in a thunderstorm.To form there needs to be great difference between the properties of colliding air masses.
Thunderstorms and tornadoes often associated with cyclone of the middle latitudes.
Hurricane is a large tropical cyclone with winds at least 119 kilometres per hour.