Earth-Sun Relationships Chapter 3 Section 1 Earth-Sun Relationships

Key terms Weather Climate Axis Temperature Revolution Equinox Solstice Greenhouse effect Global Warming

Climate and Weather Weather- condition of the atmosphere in one place during a limited period of time. Climate- weather patterns that an area typically experienced over a long period of time.

Earth’s Tilt and Rotation Earth’s tilt is one reason for variations in sunlight. Axis- an imaginary line running from North Pole to South Pole. The angle is 23 ½ degrees. Temperature- the measure of how hot or cold a place is.

Fahrenheit and Celsius

Earth’s Revolution Earth is rotating on its axis but it also is traveling in an orbit around the sun. It takes the Earth 365 days and 6 hours to travel around the sun. Revolution- trip around the sun. Seasons are reversed north and south of the Equator. Spring in Northern Hemisphere means fall in Southern Hemisphere.

Tropics of Cancer and Capricorn

The Equinox and The Poles Equinox- one of two days (about March 21 and September 23) on which the sun is directly above the Equator, making day and night equal in length. At the North Pole the sun never sets from about March 20 to September 23. At the South Pole the sun never sets from about September 23 to March 20. Alaska and Northern Europe have been popular tourist destinations as “lands of the midnight sun”

The Greenhouse Effect Even on the sunniest days in the warmest climates only part of the sun's radiation passes through the earth’s atmosphere. The atmosphere traps the sun’s warmth for growing plants even in cold weather. This process is known as the GREENHOUSE EFFECT. Global Warming- caused by human activities, such as burning of coal, oil, and natural gas.