1. Winds Wind is the horizontal movement of air. Air always moves from H  L pressure. Temperature differences create pressure differences. Weather is based on the unequal heating of Earth’s surfaces. Some surfaces heat up more than others. This warms up the air and causes pressure differences …

2. Local Winds: Sea & Land Breezes http://www.classzone.com/books/earth_science/terc/content/visualizations/es1903/es1903page01.cfm?chapter_no=vis ualization

3. Local Breezes – over short distances Ex.: Sea breezes – happen during the day because LAND Heats Up FASTER THAN WATER (water takes a long time to heat up and cool down). Local Breezes – over short distances Ex.: Land breezes – happen at night because LAND COOLS DOWN FASTER THAN WATER. Air is mostly heated by I.R. re-radiated off of surfaces. Warmer surfaces  Warmer air  Less dense (more expanded)  Low Pressure Cooler surfaces  Cooler air  Denser  High Pressure Wind moves from H  L pressure

4. Air is mostly heated by I.R. re-radiated off of surfaces. Warmer surfaces  Warmer air  Less dense (more expanded)  Low Pressure Cooler surfaces  Cooler air  Denser  High Pressure Wind moves from H  L pressure Local Breezes – over short distances Ex.: Land breezes – happen at night because LAND COOLS DOWN FASTER THAN WATER.

5. Warm air More Kinetic Energy Less Dense Low Pressure Rises (less dense) Room for moisture Cold air Less Kinetic Energy Denser High Pressure Sinks(denser) Dry (less room for moisture)

6. MOONSOON RAINS are seasonal and experienced in India & S.E. Asia (subtropical locations) Summer – Land is warmer (Low Pressure) than Water (High Pressure). Air moves from water to land carrying moisture --- RAIN. It can rain 37 ft of rain in a few months. Remember … Land heats up faster than water. Winter – Land is cooler than water. Air moves from land to water – this is a DRY SEASON Regional Winds: Monsoon Winds

8. Regional Wind Patterns: El Nino & La Nina Natural short range change in climate due to change in wind pattern and ocean currents.

9. El Nino: Periodic warming of water in the central & eastern Pacific Ocean (off coast of Peru) Normally this water is VERY COLD due to an upwelling from the deep ocean. Warm water  warmer air  Less Pressure = trade winds slacken or weaken Ocean currents in Pacific weaken or reverse direction (b/c trade winds weaken) Result: Abnormal weather (Rain on West Coast; Milder Winter on East coast; more Drought in Austrialia, and S.E Asia When: Every 8 yrs (average)

10. Normal Years Cold water off S. America  High pressure air = Trade Winds blow AWAY from S. America across Pacific (Dry air in Western Americas) El Nino Years Warmer water off S. America  Less High pressure air = Trade Winds WEAKEN or reverse Changes what locations get rain/snow/or draught

11. El Nino year La Nina – cooler water El Nino– Warmer water La Nina = Opposite of El Nino Year when the cold current off the coast of S. America is “extra” cool. Air off coast of S. America = High Pressure

12. GLOBAL WINDS – DUE TO DIFF. IN PRESSURE Warm air rises at the equator and cold dense air sinks at the poles. In general wind want to move from Poles  Equator, but E’s rotation CURVES the path of wind. CORIOLIS EFFECT – DUE TO EARTH’S ROTATION, CURVES THE PATH OF THE WIND. Wind & Surface Currents deflect TO THE RIGHT in the N. Hemi; TO THE LEFT in the S. Hemi. WARM AIR RISES – LOW PRESSURE COOL AIR SINKS – HIGH PRESSURE http:// www.classzone.com/books/earth_science/terc/content/visualizations/es1905/es1905page01.cfm?chapter_no=visualizatiohttp:// www.classzone.com/books/earth_science/terc/content/visualizations/es1905/es1905page01.cfm?chapter_no=visualization http://www.mhhe.com/biosci/genbio/tlw3/eBridge/Chp29/animations/ch29/global_wind_circulation.swf Global Winds

13. http://www.coolschool.ca/lor/GEO12/unit9/U09L03.htm Global Winds: Warm Low Pressure Air (carrying moisture) Rises @ Equator and Sinks @ 30 N & S (dry, sinking, high pressure air)

14. http://www.ukdivers.net/meteorology/coriolis.htm Global Winds: There are 3 major convection cells of rising and sinking air for each hemisphere. Due to Coriolis: Air deflects to the Right in the N. Hemi. And to the Left in the S. Hemi. Remember: start at the BASE of the arrow.

17. Winds Aloft (high in Troposphere) JET STREAM – Rivers of high speed wind at the top of the troposphere. Separates cold Canadian air from warm Gulf air. Steers weather. When jet stream dips south, NJ gets cold Canadian air. When jet streams moves north, NJ gets warm Gulf air. Jet Stream: http://www.wunderground.com/US/Region/US/pxJetStream.html

18. http://www.pbs.org/wgbh/nova/vanished/jet str_giving.html Current Jet Stream Animations: http://www.wunderground.com/global/Regi on/EU/pxJetStream.html