WEATHER

1. WEATHER Can you weather a quick review of the atmosphere?

2. The Atmosphere Gravity causes the Earths atmosphere to be MORE dense near the Earth’s surface!So at higher elevations, the air becomes LESS dense!

3. Layers of the atmosphere?

4. Troposphere • Nearest Earth’s surface • About 18 km high • Densest layer • Within this layer temperature decreases as altitude increases

5. Stratosphere • Above Troposphere • 18 km to 50 km • Contains ozone layer • Ozone* molecules absorb UV energy from the sun and heat up this layer • Therefore, temperature Increases as altitude increases *Ozone O3 reduce UV radiation that reaches the Earth

6. Mesosphere • Above the Stratosphere • 50 km to 80 km high • Coldest layer • Temperature decreases as altitude increases

7. Thermosphere • Farthest from Earths surface • 80km-550 km • N2 and O2 absorb solar radiation • Temperatures of 2000 C • Molecules in this layer absorb harmful x-rays and gamma rays from the sun, causing atoms to become electrically charged ions

8. The Movement of Air Around the Earth • Weather – state of the atmosphere at a given time and place • Or a change in the state of the atmosphere at a given time • Most weather occurs in the Troposphere • So, less dense air warmed by the Earth’s surface rises, as air currents rise, they cool, become more dense, and sink. • The continual process of warm air rising and cool air sinking in a circular motion- Convection Currents!

9. Convection Currents in the Atmosphere Where else have we seen convection currents?

10. Weather vs. Climate Climate  Average weather of some place over a long period of time

11. The Greenhouse Effect Process in which gases trap heat neat the Earth’s surface

12. Greenhouse Effect and Global Warming • Is global warming affecting the occurrence of hurricanes and tornadoes?