Climate and What Influences It

Chapter 2, Section 3

Reach Into Your Background

• What is the worst weather you have ever experienced?

• How did you feel? • How did you stay safe?

Weather or Climate?

• Weather the day-to-day changes in the air– Measured primarily by temperature and

precipitation– Temperature how hot or cold the air feels– Precipitation water that falls to the ground as

rain, sleet, hail or snow

Weather or Climate?

• Climate is not the same as weather• Climate of a place is the average weather

over many years• Climate is what people know from experience

happens every year

Latitudes, Landforms, and Climate

• The Earth has many climate regions.• Geographers know climates are different in

the low, middle, and high latitudes, because latitude affects temperature.

• Major landforms such as mountains also affect climates in neighboring areas.

• Wind and water also play a role.

The World: Climate Regions

Wind and Water

• Without wind and water, the Earth would overheat.

The Blowing Winds

• The Earth’s rotation creates our winds.• Air moves in an east-west direction.• Two factors move air in a north-south

direction1. Hot air rises and circulates toward regions where

the air is not as hot.2. Cold air sinks and moves toward regions where

the air is warmer.

The Blowing Air

• As a result, hot, moist air from the Equator rises in the atmosphere, then moves toward the North Pole or the South Pole.

• Cold, dry air from the poles moves toward the Equator.

• This movement helps the Earth from overheating.

Ocean Currents: Hot and Cold

• The Earth’s rotation also creates ocean currents, which are like fast-moving rivers in the oceans.– Ocean currents travel great distances– Warm water from near the Equator moves north

or south.

Ocean Currents: Hot and Cold

• Atlantic Ocean The Gulf Stream– A warm current travels north and east from the

tropics– The Gulf Stream merges with the North Atlantic

Current to carry warm water all the way to the British Isles

– Mild climate

Ocean Currents: Hot and Cold

• Pacific Ocean The Peru Current– Moves north from Antarctica , along the coast of

South America, and on to the Galapagos Islands– These islands sit on the Equator, but the current is

cold enough for penguins to live there

The World: Ocean Currents

The Ocean’s Cooling and Warming Effects

• Bodies of water affect climate in other ways• San Francisco, CA & St. Louis, MO– Both cities have an average temp. or 55 degrees F– Climates are different!• San Francisco borders Pacific Ocean

– In the winter, the ocean current is warmer than the air, so the current gives off warmth and the air temperature rises

• St. Louis midwest– Winter much colder than San Fran.– Summer current is colder than the air, so the current absorbs

heat, making the air temperature fall

Raging Storms

• Wind and water can create storms• Hurricanes wind and rain storms that form

over the tropics in the Atlantic Ocean– Winds at the center can travel 73mph– Can reach speeds of more than 100mph– Produce huge waves called storm surges

• Typhoons take place in the Pacific Ocean• Affect large areas

Raging Storms

• Tornadoes– swirling funnels of wind that can reach 200mph– affect smaller areas– The winds and vacuum they create in their centers

can wreck almost everything in their path

• Blizzards– Dump huge amounts of snow in parts of North

America