Weather, Climate, Air Masses, and Global Winds

WEATHER and Climate Vocabulary jet streamocean currentsglobal winds latitude longitudealtitudeair massGulf Streamweatherclimate

WEATHER VS. CLIMATEThe 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 climateClimate is different from weather

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.

Patterns That Affect Temperature

Tropical Zone

Polar Zone

Temperate Zone

Distance from Large Bodies of WaterAlaska 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.

Patterns That Affect Temperature (cont.)

• 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?

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.

Patterns That Affect Temperature (cont.)

Global Winds

Patterns That Affect PrecipitationThe 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 PrecipitationJet 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 MASSA large body of air throughout which temperature and moisture are similar.

EX:Continental air mass: form over large landmassesMaritime air mass: form over oceansTropical 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 MassesAir masses can be classified according to temperature and humidity.

North American Air MassesAir masses can be warm or cold, and humid or dry.

Air Masses and Their Movements

Types of FrontsWhat type of weather is brought by each front?

Air Masses and Their Movements

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.

Sea BreezeWind that moves from a large body of water to land

Land BreezeThe flow of air from land to a body of water

DEMO

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.

GizmoPracti

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