1. Natural Variations in Climate

2. 1. El Nino and La Nina Natural changes in climate due to warmer or cooler than normal surface water in the eastern Pacific

3. Normal Conditions/Trade Winds Normally, strong trade winds blow from the east along the equator, pushing warm water into the Pacific Ocean.

4. El Nino El Nino – unusual ________ of ocean temperatures of Pacific Ocean results from weakened or a reverse in trade winds in the western Pacific Ocean, allowing piled-up warm water to flow toward South America. warming

5. El Nino Weather in the US Northeast United States is warmer Western US is stormy Southern US is cold and wet

6. La Nina unusual _________ of ocean temperatures of Pacific Ocean Results in stronger low-level winds along the equator Northern US  harsh winter conditions Southern US  drier and warmer condition cooling

7. El Nino or La Nina – 2014/2015? El Nino La Nina Based on our winter, do you think its an El Nino year or a La Nina year?

10. 2. Solar Cycle

11. 3. Ice Ages Milankovitch Cycle – Gradual changes in Earth’s rotation and orbit have changed the intensity of sunlight received in our planet’s polar and equatorial regions

13. Ice Ages are cyclic. The last one occurred ~12,000 years ago The exact cause of what triggers an ice age is not known

14. Earth’s Tilt

15. Earth’s Wobble Currently points toward Polaris but every 13000 years it will point toward Vega

16. Earth’s orbit B.

19. http://www.youtube.com/watch?v=gaJJtS_ WDmI

20. 4. Volcanic Eruptions Large quantities of Volcanic Ash that are released into atmosphere which blocks incoming solar radiation, Thus, cools the earth

21. Mt. Pinatubo Erupted in 1991, caused cooler temps around the world for about 2 years.