Atmosphere Flashcards
What is atmosphere?
thin layer of homogeneous mixture of gases extending 90KM above Earth
What is the composition of air?
Nitrogen 78%
Oxygen 21%
Other 1%
What is density of air controlled by?
temperature
water vapor
altitude
What is the relationship between air temperature and density?
Warm air is less dense than cold air
What is the relationship between air humidity and density?
Humid air is more dense that dry air
What is the relationship between air compression and density?
more compression means more dense
What is atmospheric pressure?
pressure at any given point on Earth exerted by the atmosphere as a consequence of gravatational force exerted on the colum of air directly above.
What is the average sea pressure?
1013.25 Milibars
14.7 lbs. in
What are low pressure zones?
density of air is less than average
What happens to air in low pressure zones?
Air rises
What are high pressure zones?
density of air is more than average
What happens to air in high pressure zones?
Sinks
Why does air move?
less dense air rises
more dense air sinks to Earth
Which way does Earth Rotate?
West ot East
How does latitude impact speed of rotation?
As latitude decreases, roation speed increases
What is the coriolis effect?
Force acting on a body in motion due to the rotation of the Earth causing deflection.
How does the coriolis effect impact the hemispheres?
Earth Rotates to the **right **in the North hemisphere
and Left in the Southern hemispere
What is deflection in relation to the coriolis effect?
amounts of deflected win is dependent on **speed **and location
Which winds deviate the most?
polar, and fast winds
Which wind deviates the least?
tropical, and slow winds
How are winds named?
By the direction they are moving
What are rising air areas?
Doldrums
What are high pressure areas?
horse latitudes
What is the ITCZ?
Intrtropical convergence zone
What happens at the ITCZ
area of rising air and high atmospheric pressure near equator
Where wind systems of Northern and Southern Hemispheres converge
What happens to land and ocean in summer months?
land is warmer than the ocean
low pressures develop global high pressure belt
What happens to air in the summer?
moves away and deflects right.
What happens to land and ocean during winter months?
land is colder than the ocean.
high pressure zones separate low pressure zones over water
How does air move during winter months
Pulls in and deflects right
How does air move when theres counterclockwise roation at low pressure?
Moves in and deflects right
What are modern scale circulations?
rising air over land replaced by warm moist air
Carried on southwest winds from Indian ocean
Offshore airflow causes condensation
What is rain shadow?
Mountains deflect wind upward:cools
riding on windward side of mountain; heavy precipitation
Descending air on leeward side: low precipitation
What is an example of a small scale circulation pattern?
land sea breezes
What are hurricanes?
tropical cyclonic storm wind speeds of 73 mph
When do hurricanes occur?
tropical oceans when surface water temperature exceeds 28 celcius
What is a storm surge?
elevation of sea surface beneath the center of a storm caused by low intense pressure
What is a storm tide?
**max. sea surface elevation **when storm surge collides with high tide
