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Meteorology. Pg.75. Causes of weather. Greek meaning of meteor- high in the air Types of atmospheric meteors: Hydrometeors- cloud droplets and forms of precipitation Lithometeors - smoke, haze, dust, and other condensation nuclei Electrometeors - thunder and lightning. Climate vs. weather.
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Meteorology Pg.75
Causes of weather • Greek meaning of meteor- high in the air • Types of atmospheric meteors: • Hydrometeors- cloud droplets and forms of precipitation • Lithometeors- smoke, haze, dust, and other condensation nuclei • Electrometeors- thunder and lightning
Climate vs. weather Weather is the current state Climate is the long term variations in weather Climate is usually measured over the course of 30 years
Distribution of radiation Sun’s rays are more spread out when they strike at a lower angle Why its cooler in the morning and evening than mid-day Same amount of energy is spread out more Poles receive less radiation
Balancing radiation continual motion of air allows for distribution of heat and radiation tropics are able to maintain constant temperatures instead of constantly rising Any type of weather changes brings redistribution of heat energy
Air masses When air over a warm surface is warmer than surrounding air and stays for a long period- air mass Takes on the characteristics (including temp) of the area over which it forms The area is called the source region Can form over land or water Over land-drier air masses
Classifying air masses • Warm and dry continental tropical (cT) • Warm and humid maritime tropical (mT) • Cold and dry continental polar (cP) • Cold and humid maritime polar (mP) • Arctic (A) • Same as continental polar but much colder • Associated with high pressure
Source regions All 5 air masses are found in North America mP- forms over North Atlantic and North Pacific; primarily affects the west coast cP- forms over interior Canada and Alaska; frigid winters but pleasant spring and summers because dry mT- Caribbean sea and Gulf of Mexico; brings hot oppressively humid weather to eastern US and Canada cT- desert Southwest and Mexico; hot and dry A- develops over latitudes above 60o N in Siberia; during winter receives almost no radiation
Air mass modifications Stability of an air mass is important- factor in ability to produce clouds When an air mass moves to another location, it takes on new characteristics of source region Undergoes air mass modification Eventually loses all characteristics of original region