thin, gaseous envelope of gases
99% lies within 30 km of earth's surface
No definite upper limit
protects us from UV rays
varying concentration depending upon where/when you are. All weather and climate are associated this.
Permanent gases:Nitrogen 78%, Oxygen 21%
Variable gases: Water vapor (H2O), Carbon dioxide (CO2),
Ozone (O3), Aerosols & Pollutants
Variable gas - Water Vapor
More vapor in warmer locations, less in colder
Only substance that exists in 3 phases near the surface, Phase changes (condensation) form clouds and drive weather
Greenhouse gas - absorbs earth's radiation to keep the surface warm
Carbon Dioxide Sources
Decay of plants
Exhalation of animals
Burning fossil fuels
Why is Ozone high in the atmosphere a good thing?
blocks out harmful UV rays, and is formed naturally. When it is low it create photochemical smog (created by humans)
What causes an Ozone hole?
1) CFC's breaking down into chlorine in the presence of UV radiation then
2) the chlorine reacts with ozone resulting in ozone destruction
Variable component - Pollutants
products from incomplete combustion of fossil fuels react with sunlight to form smog and acid rain
Vertical Structure of Atmos
Atmosphere has no definite top, rather thinning out gradually.
Changes in atmospheric properties describe vertical structure.
Vertical structure determines weather and climate.
Where is atmosphere most crowded and most dense?
Most of atmosphere is crowded near the surface
More dense closer to the surface, with density decreasing rapidly with height
is a measure of the weight of a column or air over an area. It is defined as force divided by the area
decrease in temperature, day to day weather. All weather occurs here Strong turbulent mixing forced by surface heating. (7 miles)
is the current state of the atmosphere at a specific time and place. This constantly changes because of temperature, precipitation, pressure, visibility, humidity, winds.
is the average weather at a particular location. Accumulation of daily and seasonal weather events over a long period. This happens very slow.
List the four most abundant gases in today's atmosphere.
Nitrogen, Carbon Dioxide, oxygen, Water vapor
Of the four most abundant gases in our atmosphere,
which one shows the greatest variation at the earth's surface?
What are some of the important roles that water plays in our atmosphere?
It absorbs CO2, It plays an important role in the heat energy balance. 1) helps transformation from gas to liquid help form latent heat (this an important source for Atmospheric energy), 2) It is also a green house that absorbs the earths out going radiant energy,