Chapter 19 the Atmosphere in Motion

Chapter 19 The Atmosphere in Motion

I Air pressure and the wind

A.  What is air pressure?

1.  A column of air that reaches from sea level to the tom of the atmosphere pushes down at ______per square inch

2.  Air pressure – is the ______of the overlying atmosphere

3.  It is exerted in ______directions

4.  Force pushing on your body is balanced by your body ______out

5.  The higher you go into the atmosphere the ______the pressure

6.  Barometers – used to measure air ______

Aneroid – ______can with read outs attached and barograph

a.  Mercury p 414

7.  Units of air pressure

a.  inches or millimeters – used to read ______

b.  ______bars used on weather maps – these are adjusted to sea level pressure due to altitude differences

B.  Why does air pressure Change

1.  Elevation – higher up _____air pressure

2.  Temperature – the ______(more spread out) the less Air P.

3.  Water Vapor – the more water vapor the ______the A.P. – H2O molecules weigh less than the N & O molecules in the air

4.  ______– lines of equal pressure – closed isobar forms a closed lop on a map

5.  If pressure increases toward center it is a _____Pressure Center

6.  Low pressure center – pressure is______

7.  Pressure Gradient – how ______the isobars are. Close together – large gradient

C.  What makes the wind blow

1.  Difference in A.P. – the greater the difference the faster the winds. The ______the ______the faster the wind

2.  A wind blows form______. to low ______

e.g. Hot air on an island rises (form L.P.) Cool air from the water (H.P) rushes in, this is known as a ______

D.  Measuring surface wind direction and speed.

1.  ______– measure the direction from which the wind is blowing – Winds are named by the direction they come ______

e.g. westerly or sea breeze

2.  Anemometer – measure ______

II Factors affecting Wind

1.  ______Effect

1.  If the earth did not spin and was perfectly smooth air would flow strait from ______pressure areas(poles) directly to ______pressure areas(equator)

2.  Coriolis effect causes objects traveling freely over the earth to curve

a.  In n. hemisphere curve ______

b.  In s. hemisphere curve ______

c.  The effect is greater near the ______

d.  The effect is also greater in ______diastase travel vs. short travel

e.  The effect increases with increased ______

3.  Friction – with the earth’s surface slows winds down. The ______surface(water) the faster wind can blow the ______coriolis effect

4.  The coriolis effect is a strong factor in determining wind direction as is a ______gradient speed

5.  Coriolis causes winds to blow ______in a low, clockwise in high

6.  Jet stream – swift winds due to ______– direct path of storms

III Global Wind Patterns

1.  Non rotating earth would allow warm air to ______at the equator, move to the poles and ______to travel back to the equator, resulting in large circulation cell

2.  The corriolis effect (______of earth) prevents this from happening

3.  3 ______circulation model

4.  Weakness of 3Celled model

a.  gives simplified view of circulation between ______and ______

b.  No effect given to continents or season

c.  Simplifies upper level winds

B. Description of Wind and Pressure Belts

1.  ITCZ (______) occurs at the equator

a.  ______and humid with little or no wind

b.  ______is common

c.  historically been called the ______P_

2.  between 20° and 35° air sinks forming ______highs, location of earth’s deserts. Known as ______

3.  between the doldrums and the horse latitudes are the easterly ______

a. Warm and ______(speed and direction) winds

IV Continental and Local Winds

A.  effects of Seasons and continents

1.  Seasons, land masses and topography causes ______to vary from global patterns depicted in the 3cell model

2.  Hot air above land is summer creates ______-pressure cold air. Above oceans in summer creates high pressure

e.g. ______Highs bring winds off the ocean into the eastern sea board. Winter is reversed

3.  ______– winds caused by seasonal pressure changes

B.  Local winds – extent 100 km or less include ______breeze, lond breeze, mountain breeze and valley breeze

1.  Sea – land breeze - During day land is warmer creating low pressure above` causes the ______air(H) to blowing from the water (sea) and night it reverse

2.  Mnt. Breeze – at night the air against the mountain cools more than the surround air and ______down hill

3.  ______breeze – mountain heats the air causing it to rise and the air from the valley flows up hill