1. Atmospheric Circulation Earth and Space Science Ms. Pollock 2009 - 2010

2. Coriolis Effect Circulation of Earth’s atmosphere and oceans affected by Earth’s tilt on axis Circulation of Earth’s atmosphere and oceans affected by Earth’s tilt on axis Air at equator moving faster than air at poles, so it curves Air at equator moving faster than air at poles, so it curves Coriolis effect – tendency of a moving object to follow a curved path rather than a straight path because of Earth’s rotation Coriolis effect – tendency of a moving object to follow a curved path rather than a straight path because of Earth’s rotation

3. Coriolis Effect http://earthsci.org/processes/weather/cycl one/crls.gif http://earthsci.org/processes/weather/cycl one/crls.gif

4. Coriolis Effect Winds blowing from high pressure areas to low pressure areas curve due to the Coriolis effect. Winds blowing from high pressure areas to low pressure areas curve due to the Coriolis effect. The greater the speed, the greater the Coriolis effect. The greater the speed, the greater the Coriolis effect. Generally only detectable in fast-moving objects or over great distances. Generally only detectable in fast-moving objects or over great distances.

5. Global Winds Winds do not blow in straight lines. Winds do not blow in straight lines. Three looping patterns in each hemisphere – convection cells Three looping patterns in each hemisphere – convection cells Convection cells related to wind belts (winds flowing in one general direction) Convection cells related to wind belts (winds flowing in one general direction) Wind belts also called prevailing winds Wind belts also called prevailing winds Six wind belts Six wind belts

6. Global Winds http://www.csa.com/discoveryguides/prednino/images/w inds.gif http://www.csa.com/discoveryguides/prednino/images/w inds.gif

7. Trade Winds 30° to 0° latitude in both hemispheres 30° to 0° latitude in both hemispheres Flow toward equator Flow toward equator Named according to direction of flow Named according to direction of flow Used by trading ships in 18 th and 19 th centuries Used by trading ships in 18 th and 19 th centuries http://www.acmecompan y.com/stock_thumbnails/ 13007.global_winds_1.jp g http://www.acmecompan y.com/stock_thumbnails/ 13007.global_winds_1.jp g

8. Westerlies 60° to 30° latitude 60° to 30° latitude Descending air moving toward poles Descending air moving toward poles Blow throughout contiguous United States Blow throughout contiguous United States http://www.wonderqu est.com/fig-uncut- winds.jpg http://www.wonderqu est.com/fig-uncut- winds.jpg

9. Polar Easterlies 60° latitude 60° latitude Low-pressure areas Low-pressure areas Deflection from polar high-pressure areas Deflection from polar high-pressure areas Strongest off Antarctica Strongest off Antarctica Create fronts/storms at westerlies Create fronts/storms at westerlies http://www.kidsgeo.com/ images/polar- easterlies.gif http://www.kidsgeo.com/ images/polar- easterlies.gif

10. The Doldrums and Horse Latitudes Equator Equator Area where trade winds from Northern hemisphere and Southern hemisphere meet Area where trade winds from Northern hemisphere and Southern hemisphere meet Winds weak and variable Winds weak and variable http://ntsavanna.files.wor dpress.com/2006/12/04_ hadleys3.jpg http://ntsavanna.files.wor dpress.com/2006/12/04_ hadleys3.jpg

11. Horse Latitudes Areas of light or calm wind Areas of light or calm wind Ships sailing to New World often caught for weeks Ships sailing to New World often caught for weeks When food and water ran low, horses were thrown overboard to conserve supplies. When food and water ran low, horses were thrown overboard to conserve supplies. http://www.mostdog.com /_Media/horse_latitudes_t extmedium.jpeg http://www.mostdog.com /_Media/horse_latitudes_t extmedium.jpeg

12. Wind and Pressure Shifts Sun’s rays shift throughout year Sun’s rays shift throughout year Winds shift as rays shift Winds shift as rays shift http://endrino.pntic.m ec.es/hotp0061/p_alo nso/seasons.jpg http://endrino.pntic.m ec.es/hotp0061/p_alo nso/seasons.jpg

13. Jet Streams Narrow bands of high speed winds that blow in upper troposphere and lower stratosphere Narrow bands of high speed winds that blow in upper troposphere and lower stratosphere Cause massive weather changes Cause massive weather changes Affect airline routes and paths of storms Affect airline routes and paths of storms http://www.physicalgeography.net /fundamentals/images/globalairm asses.jpg http://www.physicalgeography.net /fundamentals/images/globalairm asses.jpg

14. Local Winds Land and sea breezes Land and sea breezes Differences in temperature caused by water Differences in temperature caused by water Mountain and valley breezes Mountain and valley breezes Differences in temperature caused by elevation Differences in temperature caused by elevation http://www.physicalgeogra phy.net/fundamentals/imag es/valleybreeze.gif http://www.physicalgeogra phy.net/fundamentals/imag es/valleybreeze.gif