Climate and Weather

1. Climate and Weather

2. Climate vs. Weather • Climate and weather are NOT the same • Weather – the condition of the atmosphere in one place during a limited period of time • Climate – the weather patterns that an area typically experiences over a long period of time. • Example: What is the weather today? vs. What is the climate of Kentucky?

3. Earth’s Tilt and Rotation • The Earth is tilted on its axis – an imaginary line running from the North to South pole through the middle of the earth • The tilt of the earth affects the temperature – the measure of how hot or cold a place is • Areas that are tilted toward the sun have warmer temperatures while areas tilted away from the sun have colder temperatures • The earth rotates. The area facing toward the sun has daylight. The area facing away from the sun has night time.

5. Earth’s Revolution • The earth not only rotates, but also revolves. • One revolution around the sun takes 365 days. • The earth’s revolution and tilt cause changes in the amount of sunlight that reach different locations on the planet. This is why we have seasons • When our area is faced more directly to the sun we experience summer. When our area is faced away from the sun we experience winter.

7. Equinox • The seasons of the world are reversed north and south of the equator • Around March 21 the sun’s rays fall directly on the equator, meaning the amount of daylight and sunlight is equal • Around September 23 it happens again

8. The Tropic of Cancer and Tropic of Capricorn • Tropic of Cancer – a line of latitude at 23.5 degrees north. The northernmost point at which sunlight directly hits the earth. • The suns rays reach the Tropic of Cancer around June 21 (the summer solstice), marking the beginning of summer in the Northern Hemisphere • Tropic of Capricorn – a line of latitude at 23.5 degrees south. The southernmost point at which sunlight directly hits the earth • The suns rays reach the Tropic of Capricorn around December 22 (the winter solstice), marking the beginning of winter in the Northern Hemisphere

10. The Poles • The amount of sunlight at the Poles varies most dramatically during the year • At the North Pole the sun never sets from March 20 to September 23. This happens at the South Pole from September 23 to March 20. • The tilt of the earth’s axis causes this phenomenon. • Since people don’t live on the poles it goes mostly unnoticed, but some living near the Arctic experience the “lands of the midnight sun”

12. The Greenhouse Effect • Only about half of the sun’s radiation passes through the earth’s atmosphere. • Some radiation is reflected back into space, and just enough passes through to warm the air, land, and water. • Earth’s atmosphere acts like a greenhouse in that it traps heat even during cold weather

14. Global Warming • Carbon dioxide (CO2) helps to absorb the heat that is reflected off the earth and send it back to the surface. • Too much CO2 could cause overheating on the earth’s surface • Global warming – a rise in atmospheric CO2 levels due to the burning of fossil fuels • Scientists do not agree on the extent of global warming but it is possible that global warming could spark climate change across the earth.