Chapter 4 Section 1The Role of Climate

• Objectives:– Identify what influences climate– Explain how Earth’s temperature range is

maintained– Identify Earth’s three main climate zones

What is Weather

• The day-to-day condition of Earth’s atmosphere at a particular time and place

• What the meteorologist gives you when you watch the news

What is Climate?

The average, year-after-year conditions of temperature

and precipitation in a particular region

Conditions that affect weather and climate:

Solar NRG

Latitude

Elevation above sea level

Greenhouse Gases in the atmosphere

Ocean and Wind currents

Greenhouse Gases

• Carbon dioxide (CO2), methane (CH4), water vapor, and a few others trap heat NRG and maintain Earth’s temperature range

Greenhouse Effect:•Natural situation in which heat is retained in Earth’s atmosphere by greenhouse gasses

Some heat

escapes

into space

Greenhouse

gases trap

some heat

As a result of differences in latitude and thus the angle of heating (angle at which the sun’s rays strike Earth), Earth has three main climate zones:

Sunlight

Most direct sunlight

Sunlight

Sunlight

Sunlight

90°N North Pole

90°S South Pole

Arctic circle

Tropic of Cancer

Equator

Tropic of Capricorn

Antarctic circle

66.5°N

23.5°N

23.5°S

66.5°S

Tropical Zone: Receives the sun’s rays most directly,

warm climateLocated between 23.50 North and 23.50

South latitudes

Temperate Zone: Climate ranges from hot to cold

according to a change in seasonsLocated between polar and tropical

zones

Polar Zone:

Cold areas where the sun’s rays strike Earth at a very low angle

Located between 66.50 and 900 N. and S. Latitudes

Unequal heating of Earth’s surface drives wind and ocean currents which distributes heat NRG throughout the biosphere

Interpret ocean and wind currents on page 89.