Weather, Climate, Air Masses, and Global Winds
WEATHER and Climate Vocabulary
 jet stream
 ocean currents
 global winds
 latitude
 longitude
 altitude
 air mass
 Gulf Stream
 weather
 climate
WEATHER VS. CLIMATE
 The average weather conditions for an area over a long period
of time are referred to as climate.
 Latitude is one of the most important factors that
determines a regions climate
 Climate is different from weather
Weather
Climate
Patterns That Affect Temperature
Temperature is affected by latitude, altitude, distance from large bodies of
water, and ocean currents.
Latitude areas near the equator are warmer than areas far from the equator
because the sun’s rays hit Earth’s surface more directly at the equator than at
the poles.
Tropical Zone
Polar Zone
Temperate Zone
Patterns That Affect Temperature (cont.)
Distance from Large Bodies of Water
Alaska is about twice the size of Texas. Factors influencing temperature, such as
distance from large bodies of water, affect this big state in different ways.
•
•
•
Where are Juneau and
Fairbanks located in relation
to each other?
Which climate data do you
think describe Juneau?
Fairbanks?
Which city on the map do
you think represents the set
of data for City C? Why?
Patterns That Affect Temperature (cont.)
Areas along the coasts are influenced by ocean currents. Some ocean
currents warm the air above it therefore bringing mild, humid air to certain
areas that have mild, wet climates (usually high latitude areas). Cold
currents can also affect weather patterns by bringing cool air.
Global Winds
Patterns That Affect Precipitation
The main factors that affect precipitation are prevailing winds, the
presence of mountains, jet streams, and seasonal winds.
• What happens to the humid air when it encounters the mountains?
• Shade in the landscape below to show what the vegetation may look
like on the windward and leeward sides of the mountain range.
Patterns That Affect Precipitation
 Jet streams cause a strong “river” of strong winds high
above the surface of the earth. Jet Streams are a narrow
band of strong winds in the upper atmosphere.
 Jet Streams are stronger in the winter, since the
temperature difference at the front boundaries are greater
during this time.
Patterns That Affect Precipitation
Jet Streams are narrow bands of high-speed winds. These winds blow
west to east and occur along the boundary of warm and cold air masses.
Which arrow shows the polar jet stream on the diagram? Which arrow
shows the subtropical jet stream?
AIR MASS
A
large body of air throughout which temperature and
moisture are similar.
EX:
Continental air mass: form over large landmasses
Maritime air mass: form over oceans
Tropical air mass: form over deserts of the
southwestern U.S.
Polar Air Masses: form over ice and snow covered
land.
Air Masses and Their Movements
Types of Air Masses
Air masses can be
classified according to
temperature and humidity.
Air Masses and Their Movements
North American Air Masses
Air masses can be warm or cold,
and humid or dry.
Air Masses and Their Movements
Types of Fronts
What type of weather is
brought by each front?
Warm Front
Cold Front
Occluded Front
Stationary Front
How can local winds effect weather and climate?
The unequal heating of Earth’s surface within a small area causes local
winds.
DEMO
Sea Breeze
Wind that moves
from a large
body of water to
land
Land Breeze
The flow of air
from land to a
body of water
LOCAL WINDS
 Sea breeze: Cooler air that moves in toward the land
again to replace the warm air that is rising. This air then
moves inland from the water
 Land breeze: Since land cools quicker than water, air
over the warmer water rises and flows toward the cooler
land where the air sinks.
Gizmo
Practice