*Atmospheric Pressure

*aka air pressure*Caused by*Units

*14.7 psi*Why aren’t we crushed?*Air pushing out*Used to it

*Decreases with altitude/elevation

*Wind – What is it?*Air moves from high

pressure to low pressure*Wind*Larger pressure

differences = stronger winds

*Named for direction*Wind chill*What temp. feels like to us*Humans only

*Cause*Related to dangerousness

of wind and cold temp.*Frostbite*Hypothermia

*Local Wind*Land warms/cools faster*Hot air rises*Lower pressure over land

*Breeze from ocean (high to low pressure)*Cools the land

*Opposite at night

*Chinook Winds*What?*Warm winter winds*Dramatic temperature changes

*Where?*Mountains*Moist air

*How?*Clouds formed*Heat released

*Warmer air than without clouds*Red belt

*Changing Weather -

Air Masses*Similar temp. and humidity*Air that has stayed in a place*Quickly change because they move

*Named for where they form*Maritime vs. Continental*Tropical vs. Polar

*Daily Review #3

3. What is wind chill and why is it important to humans?

4. What creates wind?5. How are Chinook winds created?6. How can the wind be a benefit to

you when you live on the ocean shoreline?

7. A maritime tropical air mass exists over Colorado today, what would the air be like?

*Fronts*Air masses don’t mix*Front = boundary

between them*What happens?*Warm, less dense

air moves up*Cold, more dense

air sinks

*Types*Cold*Warm*Stationary*Occluded

*Type of cloud can tell you what type of front

*Tornadoes*Form in severe thunderstorms*Wind at different altitudes is

different speeds*Creates swirling winds*Eventually become vertical

*Swirling cloud reaches ground = tornado*Not on ground for long*Extremely low pressure*Winds 100-400 mph*Not well understood

*Daily Review #4

8.Describe how warm, cold, stationary and occluded fronts are different.

9.Explain how a tornado is formed.

10. Where would you probably not find tornadoes and why?

*Global Wind*Unequal heating at different

latitudes*Equator (lower latitudes)*Warmer air*Rises, lower pressure*Moves towards poles* Sinks when cools, higher pressure

*Convection cells* Patterns of moving air and high/low

pressure*Create areas of high and low winds

* Jet stream*High speed wind*Upper troposphere, lower

stratosphere*No consistent path* Effect weather patterns

*Coriolis Effect*Wind moves in a straight line*Earth’s rotation*Causes appearance of curving*Northern Hemisphere = clockwise (right)*Southern Hemisphere = counter-clockwise (left)

*Cyclones*Large weather systems* Impacted by Coriolis

effect*Cyclone*Low pressure*Pulls air in and

upward*Produces storms

*Anti-cyclone*High pressure*Air moves out and

downward*Clear skies

*Hurricanes*Winds at least 74 mph*Form over tropics*Warm, moist air forms

clouds*Rotating*More water evaporates*Creates low pressure “eye”*Lacks wind

*Gets larger with more evaporation

*Loses energy once it hits land*No more “fuel”

*Cyclones, typhoons, hurricanes