Download WEATHER

A PERFECT WORLD
COLD
SURFACE IS ALL
OCEAN
NO ROTATION
HOT
NO TILT
Rotational Velocities
EFFECTS OF ROTATION
NORTH POLE
GROUND
ROTATES AT LESS
THAN 1000 MPH
AS YOU MOVE
AWAY FROM
EQUATOR
EQUATOR
AIR AT EQUATOR
ROTATING AT 1000 MPH
WARM AIR RISING FROM THE EQUATOR MOVES NORTH
RESULT:
• AIR MOVING NORTH
FROM EQUATOR
DRIFTS EAST ABOVE
SLOWER MOVING
GROUND
EFFECTS
OF
ROTATION
CORIOLIS
FORCE
Animations of effect of
Coriolis Force
http://www.physics.orst.edu/~mcintyre/coriolis/East_QT.html
http://www.physics.orst.edu/~mcintyre/coriolis/North_Pole_GIF.html
http://www.physics.orst.edu/~mcintyre/coriolis/North_Lon_GIF.html
ZONAL WIND
SYSTEMS
POLAR
LOW
SUBTROPICAL
HIGH
DOLDRUMS
WESTERLIES
TRADE WINDS
ZONAL WIND SYSTEMS
WHERE CONVECTIONS CELLS MEET
convergence
divergence
ZONAL WIND
SYSTEMS convergence
POLAR
LOW
SUBTROPICAL
HIGH
DOLDRUMS
WESTERLIES
TRADE WINDS
divergence
convergence
Seasons Due to Tilt of Earth
CHANGES IN THE ANGLE OF
THE SUNLIGHT PRODUCE
SEASONS
SUMMER
WINTER
SUNLIGHT
WHEN THE SUN IS OVERHEAD THE
LIGHT FOCUSES ON A SMALL AREA
A LOW ANGLE SPREADS THE
ENERGY OUT
Air Masses
• relatively large bodies of air
• fairly horizontally uniform in characteristics
– temperature
– moisture
• may extend across an entire continent
• boundary separating two different air
masses is called a front
Types of Air Masses
• Five air masses affect the United States
during the course of a typical year:
–
–
–
–
–
continental arctic (cA)
continental polar (cP)
continental tropical (cT)
maritime polar (mP)
maritime tropical (mT)
dry, very cold
dry, cold
dry, warm
moist, cold
moist, warm
Air Mass Sources