2Air MovementWind is the horizontal movement of air from high pressure to low pressure. It is caused by differences in air pressureThe greater the difference, the faster the wind moves
3Air PressureDifferences in air pressure are caused by the uneven heating of EarthCool, denser air with a higher pressure flows underneath the warm, less dense air. This forces the warm air to rise.
4Wind Vane- measures wind direction Wind Vane- measures wind direction.- tells you where the wind is coming from. Ex: a north wind comes FROM the north.Barometer- measures air pressureAnemometer- measures wind speed.Wind chill factor- the increased cooling a wind causes.
5Wind ChillWhy does a cool breeze feel refreshing in the summer, but cold in the winter?Wind blowing over your skin removes body heat. The stronger the wind, the colder you feel.
6Local WindsGenerally move short distances and can blow in any directionCaused by geographic features that produce temperature differencesCaused by the unequal heating of Earth’s surface within a small area.
7It takes more energy to warm up and cool down a body of water than it does to warm up land. Wherever the cool air is located, that is the type of breeze. Ex: sea breeze- cool air is over the sea.
8Sea BreezesHigh pressure is created over the ocean (cooler air) during the day and low pressure (warmer air) over land due to uneven heatingAir moves from the ocean to the land creating a sea breeze
9A. Sea Breeze Happens during the day. Land warms up faster than the water.Air over the land becomes warmer than air over the water.The warm air expands and rises, creating a low-pressure area.Cool air blows inland from over the water and moves underneath the warm air, causing a sea breeze.Sea Breezes blow FROM THE SEA.
12Land BreezesLow pressure occurs over the ocean during the night and high pressure over land due to the uneven heating of earthThis causes wind to move from the land to the ocean creating a land breeze
13B. Land Breeze 1.Happens at night. Land cools more quickly than water. Air over the land becomes cooler than air over the water.Warmer air over the water expands and rises.Cooler air from land moves beneath it.Land Breezes blow FROM THE LAND.
22As warm air rises at the equator and moves toward the poles, it cools Pressure BeltsAs warm air rises at the equator and moves toward the poles, it coolsAs it cools, some of the air sinks around 30° north and south of the equator
23At the poles, cold air sinks and moves towards the equator Pressure BeltsAt the poles, cold air sinks and moves towards the equatorAround 60° north and south, the air begins to heat up and rise
24A. Coriolis EffectAs the winds blow, Earth rotates from West to East underneath them, making it seem as if winds are curving.Global winds in N. Hemisphere turn toward right.S. Hemisphere, winds curve toward left.
25These are polar easterlies, westerlies, and trade winds Global WindsThe combination of pressure belts and the Coriolis Effect cause global windsThese are polar easterlies, westerlies, and trade winds
26Global WindsWinds that blow steadily from specific directions over long distances.Created by the unequal heating of Earth’s surface.Near the equator, sun’s rays strike earth directly. Near the poles, sun’s rays do not strike Earths’ surface directly.The sun’s energy is spread out over a larger area, so it heats the surface less. Therefore, temps. Near the poles are lower than near the equator.
275. Temp. differences btwn equator and poles create giant convection currents, movements of air between the equator and poles.6. Warm air rises at the equator and cold air sinks at the poles.7. Air pressure tends to be lower near the equator and greater near the poles.Winds at the surface blow from poles toward equator. High in the atmosphere, air flows away from the equator toward the poles.They curve because of Earth’s rotation.
29Wind belts that extend from the poles to 60° latitude Polar EasterliesWind belts that extend from the poles to 60° latitudeFormed from cold sinking air moving from the poles creating cold temperatures
30E. Polar EasterliesCold air near poles sinks and flow back toward lower latitudes (away from the poles).Mixing of warm and cold air along the polar front has major effect on weather in US.
32Wind belts found between 30° and 60° latitude WesterliesWind belts found between 30° and 60° latitudeFlow towards the poles from west to east carrying moist air over the Unites States
33D. Prevailing Westerlies mid-latitudes, btwn 30 and 60 North and South, winds blow toward poles are turned toward the east by Coriolis effect.Winds blow west to east.PLAY IMPORTANT ROLE IN WEATHER IN USA.
35Winds that blow from 30° almost to the equator Trade WindsWinds that blow from 30° almost to the equatorCalled the trade winds because of their use by early sailors
36C. Trade WindsCold air over horse latitudes causes high pressure when it sinks.High pressure causes surface winds to blow toward equator and away from it.Winds that blow toward equator are turned west by Coriolis effect.Winds are high and they help ships get across the ocean.In the Northern Hemisphere, they move from the NE. In the Southern Hemisphere, they move from the SE.
38DoldrumsLocated along the equator where no winds blow because the warm rising air creates and area of low pressure
39A. DoldrumsNear equator, sun heats surface strongly. Warm air rises, creating low pressure.Cool air moves into area, but is warmed rapidly and rises before it moves very far.Little or no wind there (very calm)
40B. Horse LatitudesWarm air rises at equator and flows both north and south.At 30 degrees north and south, air stops moving toward poles and sinks.Calm air is here.
41Most deserts on the Earth are located here because of the dry air Horse LatitudesOccur at about 30° north and south of the equator where the winds are very weakMost deserts on the Earth are located here because of the dry air
42Separates warm air from cold air Jet StreamThe jet streams are narrow belts of high speed winds that blow in the upper troposphere and lower stratosphereSeparates warm air from cold air
43F. Jet StreamsBands of high-speed winds about 10km above Earth’s surface.They are hundreds of km wide but only a few km deep.Jet streams blow from west to east at speeds of km/hr.