Meteorology

read pages 282-303


 * METEOROLOGY**: the study of the entire atmosphere, including its weather
 * air is a mixture of many gases in earth's lower atmosphere
 * nitrogen and oxygen together form about 99% of dry air by volume
 * the remaining 1% is mainly argon and carbon dioxide

__troposphere__: is the lowest layer of the atmosphere (0-12 km) in which all of earth's weather occurs __tropopause__: the top of troposphere where the decrease in temperature stops __stratosphere__: reaches from the tropopause to about 50KM above earth __ozone__: ultraviolet rays make oxygen 03. the ozone layer absorbs sun's U rays and protects us from burning __stratopause__: the top oof the stratosphere where the temperature stops rising __mespsphere__: temperature drops again __thermosphere__: temperature rises again about 500 KM from earth
 * STRUCTURE OF THE ATMOSPHERE**
 * gradually decreases in temp. with an increase in altitude
 * contains al water vapor
 * the jet stream is located between (6-12km)
 * steady winds and few weather changes (planes fly here)
 * steady increase in temperature with the increase of altitude, which is caused by absorption from the ozone

weather: is the state of the atmosphere at a given time and place to try to predict weather you need to observe the clouds, wind, temperature, humidity, air pressure and precipitation over a period of time

energy from the sun results in changes in the weather. heat moves through the atmosphere in 3 ways
 * HEATING OF THE ATMOSPHERE**
 * conduction: an object receives heat when it comes into contact with a hotter object (ex. a pan on a hot stove)
 * radiation: hot bodies radiate energy in short waves (sun); cold bodies radiate energy in longer waves (earth)
 * convection: most effective; the rising of hot air and sinking of cold air results in a steady flow. convection is very important in moving heat through the atmosphere

//INSOLATION// solar energy that reaches the earth; we receive one two-billionth of the sun's rays

//GREENHOUSE EFFECT// short ultra violet waves from the sun are able to reach the earth's surface, then longer infrared waves re-radiated by the earth's surface are trapped by greenhouse gasses (CFC'S and CO2)


 * normal lapse rate**: the rate of cooling with altitude (1 degree C for every 160 meters)
 * temperature inversion**: when the air is especially still cooler air because of its greater density, settles close to the ground, and the warmer air forms a blanket above it in a temperature inversion. pollutants in the air, such as smoke and soot, are also trapper close to the ground.

SPECIFIC HEAT: the amount of heat required to raise the temperature of something 1 degree C
 * water has a high specific heat compared to soil

__absorption__: to take in energy and heat up __reflection__: to bounce back energy __re-radiation__: to absorb hot wave energy and give off long wave energy

water warms much more slowly than land
 * in water, the sun's rays go to a depth of many meters. on land, the suns rays heat only the top few centimeters of soil
 * water can spread heat easily because it is a fluid
 * some solar energy is used in the process of evaporation. thus, less solar energy is available to raise the temperature of the water
 * water cools more slowly than land because its heat is spread through a greater depth


 * TEMPERATURE**: is a measure of the energy of molecules. the more energy the molecules in air have, the hotter it feels.
 * temperature is measured in degrees (Celsius, Fahrenheit, Kelvin)

thermometers are the instruments used to measure temperature thermographs are self-recording thermometers
 * the alcohol expands when heated

isotherms are lines drawn on maps connecting places with the same temperature

differences in air pressure cause the earth;s wind and weather changes
 * AIR PRESSURE**: the weight of the atmosphere per unit area
 * pressure decreases with altitude**

barometer: is an instrument used to measure air pressure aneroid barometer: measures pressure with a thin metal can millibar: is a metric unit of pressure isobar: lines that join points having the same air pressure at a given time high pressure area (high) - the area of the largest pressure. the pressure in a high is greater than the surrounding air low pressure area (low) - this area has lower pressure than the surrounding area pressure gradient - the rate of change for air pressure between 2 points
 * standard sea-level pressure is 1012.3 MB**
 * each line is worth 4 MB

rising barometer - greater pressure usually means cooler, drier weather (sinking air) falling barometer - less pressure because the air is warm and moist and rises. this can be a sign of precipitation

winds blow from high to low ! the horizontal movement of air from areas of high air pressure to areas of low air pressure the closer the spacing between isobars the stronger the winds winds bow across isobars, from high to low air pressure
 * WIND**

global wind belts : wind flows from high pressure at the poles to low pressure at the equator
 * the wind is deflected by the earth's rotation, called the coriolus effect

equator = warm moist air ; low pressure moist air = less dense

l l l wind l H**appy = sinking cool, dry
 * L**ousy= rising warm, moist