Atmosphere - the Earth's gaseous envelope
Meteorology - the science of the atmosphere and weather
Weather - the state of the atmosphere at a particular place for a short period of time
Climate - an aggregate or composite of weather
Air contains a mixture of gases: 78% nitrogen; 21% oxygen; and 1% other gases
The amount of water vapor varies from 0 to 4%, water vapor is the most significant component of air with regard to weather
Carbon dioxide and water are both greenhouse gases - i.e. they contribute to global warming
other components of air include: dust, ozone, industrial gases, etc.
Dust scatters sunlight and acts as a nuclei for condensation. Ozone exists in the stratoshpere and absorbs uv radiation.
Chlorofluorocarbons (CFCs) destroy ozone in the upper atmosphere.
At sea level the atmosphereic pressure is 14.7 p.s.i. (pounds per square inch)
There is no sharp boundary between the atmosphere and outer space
Four layers of the atmosphere
Troposphere: the region where the air "turns over" vertical mixing of air occurs, clouds; precipitation, violent storms occur in this layer. It is called the "weather sphere". Temperature decreases about 3.5 degrees Fahrenheit for each 1000 feet of altitude. This is the normal lapse rate.
Tropopause: boundary between the troposphere and the stratosphere.
Stratosphere: emperature remains fairly constant then increases, increase caused by the absorption of energy by the ozone
Stratopause: at 50km; boundary between strotsphere and mesosphere
Mesosphere: temperature decreases with height
Mesopause: at 80km (50 miles)
Thermosphere: rarefied outermost layer of air with no upward boundary. Temperature is very high but the air is so sparse these temperatues would not be experienced by an observer.
Earth intercepts less than on billionth of the energy of the sun however this small percentage is extremely significant. Energy from the sun is the most important control of weather and climate.
Motions of the Earth: rotation and revolution
Circle of Illumination - line separating lighted half of Earth from the dark half
Revolution: movement of earth in its orbit around the sun
Rotation: the Earth turns about its axis (line from pole to pole) every 24 hours
The distance from the Earth to the Sun is 93 million miles (150 million km).
January 3rd: 147 million km - perihelion
July 4th: 152 million km - aphelion
The Sun's rays travel through more atmosphere the smaller the angle of incidence of the sunlight. This results in the sun's rays being less concentrated.
The Earth is tilted 23.5 degrees on its axis. This is what causes the seasons.
Solstice: the longest day and night
Equinox: equal hours of day and night
The Tropic of Cancer is 23.5 degrees north of the equator
The Tropic of Capricorn is 23.5 degrees south of the equator
The speed of light and all electromagnetic radiation is 300 million meters per sec. Highlights of the specturm include microwaves, infrared, visible, ultraviolet, x-rays, cosmic rays
Radiation: absorbed, scattered, reflected
Conduction: energy is transferred through collisions
Convection: movement of a mass from one place to another
Albedo: the total radiation reflected from a surface
The atmosphere is heated from the ground up.
Daily Mean = (max + min) /2
Daily Range = max-min
Monthly mean = sum of daily means / number of days in the month
Annual mean = sum of monthly means / 12
Annual temperature range: max monthly mean - min monthly mean
land and water
different surfaces absorb different amounts of solar energy - different albedos
land heats and cools more rapidly than water
Isotherms lines drawn on weather maps connecting areas of equal temperatures.