The Atmosphere Flashcards
A ___ studies the ___ (mass of air that surrounds our planet)
meteorologist
atmosphere
Name the four gases that were the predominant components of the atmosphere when the Earth was formed
ammonia
methane
water vapor
carbon dioxide
Regarding the primary components of the Earth’s atmosphere, what are the percentages of -
Nitrogen Oxygen Argon Carbon dioxide Water vapor
78 21 1 .03 and rising varies
Since Oxygen was not present in the atmosphere billions of years ago, how was it formed?
When algae developed on the Earth (~500 million years ago), they performed photosynthesis and produced Oxygen from Carbon Dioxide in the atmosphere
Humidity
Measure of the amount of water vapor in the atmosphere; usually expressed as percentage
We find high humidity in…
A place where the sun strongly heats a body of water like near an ocean and air rises over the water body
We find low humidity in…
A place where the sun heats a dry place and where air descends over land (like the desert)
Why is the sky blue?
Dust particles are present in the atmosphere. Sunlight contains all colors of the spectrum, but most of them pass straight through. The blue light is scattered by the atmosphere and the dust and reaches your eye
4 layers of the atmosphere from closest to farthest from earth
troposphere
stratosphere
ionosphere (or mesosphere)
exosphere (or thermosphere)
Troposphere
layer of atmosphere closest to earth. Between 6-10 mi. high. Weather occurs here. Temp decreases with increasing altitude
Stratosphere
Layer of atmosphere above troposphere. There is no weather here. Air is same comp as the troposphere but less dense. Contains the ozone layer that protects us from UV Radiation. Here, temp increases with height due to concentration of ozone
Ionosphere (Mesosphere)
Atmospheric layer above the stratosphere. Contains electrically charged (ionized) gases. These gases allow radio comm. by reflection of radio waves back to the Earth. Location ranges from 50-500 mi. above earth
Exosphere (Thermosphere)
Layer farthest from earth (above meso/ionosphere). Contains almost no gases (almost a vacuum). At farthest points, particles escape the Earth’s gravity and travel into outer space
Name region between troposphere and stratosphere
Troposause
Region between stratosphere and the mesosphere
Stratopause
Region between ionosphere and exosphere
Mesopause/Ionopause
The Northern Lights (or _____) and the Southern Lights (or ____) are produced by collisions between _____
aurora borealis
aurora australis
high energy particles from the sun and particles in the Earth’s ionosphere
Air pressure
The force of a given area exerted by the weight of the gases in the atmosphere. There are several units of measurement. Normal atmospheric pressure in different units: 14.7 pounds per square inch; 1 atmosphere; 760 torr or mm of mercury; 101.3 kilopascals
Barometer
Device (invented by Torricelli in 1643) for measuring atmospheric pressure. Consists of long tube filled with mercury, open at one end with a vacuum at the other closed end
How does a mercury barometer work?
Open end is immersed in a dish of mercury. When the at. pressure increases, the mercury in tube rises. A pressure decreas causes the mercury level to drop. A scale of marks on the side of the tube tell how much the pressure has changed (in a unit called “torr”)
3 factors that can change atmospheric pressure
altitude
humidity
air temp
As altitude increases, atmospheric pressure ____. Why?
decreases because there is less air that air is less dense
As humidity increases, atmospheric pressure ____. Why?
decreases because water vapor less dense than dry air
As air temp increases, atm. pressure ___. Why?
decreases; heated air particles move faster than cool particles and the air spreads out, becoming less dense/exerting less pressure
World Pressure Belts
Belt shaped regions of more constant atmospheric pressure levels that encircle the globe
4 primary pressure belts and give locations and pressure
- Doldrums - located at Equator; low pressure (due to hot temp)
- Horse latitudes: two bands on either side of doldrums; high pressure
- subpolar: two bands on either side of horse latitudes; low pressure
- polar: located at poles, high pressure (due to cold air temp)
Regarding heat energy: Particles of matter are in constant ….
motion
Regarding heat energy: in a hot substance, the particles move…
quickly