Climates

Climate is… The long-term weather patterns for

an area.

–Climate includes the annual variations of temperature, precipitation, wind, etc.

Ex: NJ is cold in January, Florida is warm and wet in the summer

Latitude At the equator, sunlight hits the Earth vertically

and is concentrated on a smaller surface area. Away from the equator, sunlight hits the Earth at an angle and spreads over a larger surface area.

Near equator (0°-23.5°)= tropics (warm) (23.5°– 66.5°) = temperate zone (moderate) Near poles (66.5°-90°) = polar (cold)

Latitude & Climates The amount of solar radiation received on Earth

decreases in intensity from the equator to the poles.

Climates are caused by:

2) Air CirculationWarm air rises & cold air

sinks

- Wind is formed when cold air

replaces rising warm air.

Warm air can hold more water vapor than cold air

- Areas with warmer temperatures tend to receive large amounts of rain.

Climates are caused by:

3) Oceanic Circulation Patterns–

Water heats up and cools off slower than land

Areas near water (coastal) tend to be warmer in winter and cooler in summer.

Oceanic CirculationEl Nino – short term (6-18 months) periodic

change in which the water is warmer than usual Pacific Ocean. Results in:

- Stronger winds in the western Pacific Ocean

- Warmer water on the west coast of North &

South Americas

- Increased rainfall in the USA & South America - Droughts in Indonesia & Australia.

- Decreased number of hurricanes in the Atlantic

Ocean

Ocean CirculationLa Nina – short term (6-18 months) periodic

change in which the water is colder than usual Pacific Ocean. Results in:

- Weaker winds in the western Pacific Ocean

- Colder water on the west coast of North &

South Americas

- Decreased rainfall in the USA & South America - Floods in Indonesia & Australia.

- Increased number of hurricanes in the Atlantic

Ocean

Climates are caused by:4) Topography–

– Temperatures decrease with increased altitude

The woman is wearing short sleeves, but there is snow on top of the mountain behind her.

Topography Orographic Lifting (high mountains)-

Moist ocean air moves up the coastal side of a mountain range. It condenses and rains or snows. Air then becomes drier as it crosses the range.

Other Influences on Earth’s Climate

The Sun can emit varying amounts of UV rays. More UV rays = more ozone in the stratosphere, warming the atmosphere.

Volcanic Eruptions release gases and ash into the atmosphere, forming dark clouds that can block sunlight and decrease temperatures.

Seasons change because the Earth’s axis is tilted. When the Earth is tilted toward the Sun (summer), the temperature increases. When the Earth is tilted away from the Sun (winter), the temperature decreases.

Seasonal ChangesThe reason for the seasons is the

TILT OF THE EARTH!

Seasonal Changes