1. Severe Weather! © The GlobalEd 2 Project Photo credit: Tyrone Turner, National Geographic Homes destroyed by Hurricane Katrina

2. Essential Questions 1.What is severe weather? Is it just one type of weather? 2.Why should anyone care about severe weather? 3.How do greenhouse gases affect severe weather? © The GlobalEd 2 Project

3. Enduring Understandings 1.There are several different types of severe weather. 2.Severe weather impacts our lives in many ways. 3.Scientists believe that an increase in greenhouse gases, will increase severe weather patterns. © The GlobalEd 2 Project

4. Examples of Severe Weather Hurricanes, typhoons, tropical cyclone, monsoons Floods Tornadoes Drought © The GlobalEd 2 Project Photo credit: Carsten Peter, National Geographic

5. Definitions A hurricane is an intense, rotating oceanic weather system that possesses maximum sustained winds exceeding 119 km/hr (74 mph). It forms and intensifies over tropical oceanic regions A tropical cyclone is composed of a system of thunderstorms that shows a cyclonic rotation around a central core or eye.cyclonic rotationeye © The GlobalEd 2 Project

6. Definitions (continuation) A typhoon is a violent tropical hurricane/cyclone that occurs in the west Pacific and the Indian Ocean. A typhoon is also a natural disaster. A tropical storm that forms over the Pacific Ocean, when winds reach 74 mph, it is considered to be a typhoon. The word typhoon comes from the Chinese term tai-fung meaning “great wind”... © The GlobalEd 2 Project

7. Definitions (continuation) A tornado is a powerful column of winds spiraling around a center of low atmospheric pressure. It looks like a large black funnel hanging down from a storm cloud. The narrow end will move over the earth, whipping back and forth like a tail. The word "tornado" comes from the Latin tonare, meaning "to thunder." The Spanish developed the word into tornear, to turn or twist. © The GlobalEd 2 Project

8. Definitions (continuation) Monsoons are seasonal winds that bring moist air from oceans and seas over land. The winds are in the reverse direction of flow from the non-monsoon season, and can generate great amounts of precipitation, as well as changes in the surface currents in the sea. © The GlobalEd 2 Project

9. Global Warming & Severe Weather Research Meteorologists found that the temperature changes brought on by global warming are significant enough to cause an increase in the occurrence of severe storms. Severe storms are those that cause flooding, have damaging winds, hail and could cause tornados. Their study revealed that by the end of this century, the number of days that favor severe storms could more than double in certain locations, such as Atlanta and New York. Source: The American Meteorological Society and the American Geophysical Union; http://www.sciencedaily.com/videos/2009/0109-global_warming_causes_severe_storms.htmAmerican Meteorological SocietyAmerican Geophysical Union © The GlobalEd 2 Project

10. Global Warming & Severe Weather “There is observational evidence for an increase of intense tropical cyclone activity in the North Atlantic since about 1970, correlated with increases of tropical sea surface temperatures.” “It is very likely that the human-induced increase in greenhouse gases has contributed to the increase in sea surface temperatures in the hurricane formation regions. “ Source: http://www.usgcrp.gov/usgcrp/links/hurricanes.htm © The GlobalEd 2 Project

11. Impact of Severe Weather Severe weather events cost billions in dollars every year Severe weather causes thousands of deaths every year No one around the world is safe from severe weather events. Temperatures can plummet or soar, winds can reach devastating levels, and rains can wipe out an area. © The GlobalEd 2 Project

12. Impact of Severe Weather Understanding the science behind these storms is crucial for both safety and public knowledge. © The GlobalEd 2 Project