Atmosphere & Ocean Currents Lesson 7, 8, 9,& 10

1. Chapter 9 (lesson 8 & 10)-Surface Currents Atmosphere & Ocean CurrentsLesson 7, 8, 9,& 10 Chapter 8 (lesson 7 & 9)-atmosphere current Angle of Incidence Convection Current Coriolis Effect Trade winds Westerlies Easterlies Sea Breeze Land Breeze • Gyre • Loop Current • Florida Current • Gulf Stream Current • Upwelling • Downwelling • El Nino • La Nina • Thermohaline circulation

2. Circulation of the Atmosphere & The Ocean Marine Science

3. Marine debris tracker • http://marineaffairs.org/marinedebris.html • Mini video of NOAA & japan tsunami debris (2min) • http://marinedebris.noaa.gov/info/japanfaqs.html

4. Introduction • Atmosphere • The volume of gases & particles surrounding Earth • Intertwined with the ocean • Weather • State of the atm at a specific time & place • Climate • Long-term average of weather

5. Composition of the Atm • Most common elements • 78% N, 21% O • Density decreases with altitude • Warm, humid air is less dense than cold, dry air • Air rises, expands, cools, falls & compresses

6. Uneven Solar Heating • Earth is spherical • Sun rays are perpendicular (equator) & slanted (as you move toward the poles) • Axis is tilted (23 degree tilt) • Seasons • Tropic of Cancer & Tropic of Capricorn) • Distance between earth and sun varies with time of year • Elliptical (not round) • Earth is closest to sun in January

7. The Reason for the Seasons • Seasons are caused by the tilt of the Earth • N. hemisphere leans toward the sun in the summer & away in the winter

8. Atm Circulation • Ideally… • Air warms at the equator, rises, expands & moves toward the poles • Air cools at the poles, contracts, sinks & moves back toward the tropics • Two large convection currents

9. The Coriolis Effect • The Coriolis Effect • Winds & waters appear to bend to the right in the N. hemisphere & to the left in the S. hemisphere • Results from the spin of the earth • Air doesn’t simply circulate from the equator  poles & back

10. Wind Systems • Areas of little wind • Equator (air rises) • Doldrums • 30o, 60o latitude (air sinks) • Horse latitudes • Wind Systems • Trade winds (+/- 15o lat) • Westerlies (+/- 45o lat) • Easterlies (+/- 75o lat)

11. Land & Sea Breezes • Result of water’s high heat capacity • Sea Breeze • Morning sun warms land faster than water • Air over land rises & expands • Cooler air from sea moves in • Land Breeze • Situation reverses

12. Monsoons • Large-scale, seasonal land and sea breezes • Spring brings rains as land heats faster than water • 2 billion people depend on monsoon rains for drinking water and agriculture

13. ExtratropicalStorms • From at the polar front (60oN) • Ex: Nor’easters • Erode beaches & barrier islands, disrupt communication, damage harbors & ports

14. Tropical Storms/Cyclones/Hurricanes • Masses of warm, humid, rotating air • Low pressure system • Winds of >73 mph qualify as a hurricane • Generated within one air mass at 10-25o latitude

15. Hurricanes Continued… • 3 aspects that cause property damage/deaths • Wind (100+ mph often) • Rain (extensive flooding) • Storm surge • Mass of water driven by a storm • Most dangerous

16. Galveston, 1900 • Highest point: 9 feet above sea level

17. Galveston, 1900

18. Galveston Today

19. What do these two things have to do with ocean currents? Explain Garabage Pacific Patch BP oil spill • http://www.youtube.com/watch?v=VT4GUhWMjog • (7 min 39 sec) • http://www.youtube.com/watch?v=IxgbvDcmrYQ • (3 min 45 sec)

20. Ocean Surface Currents Chapter 9

21. Ocean Surface Currents • Horizontally-flowing H2O in the upper-most 400m • Follow wind systems (friction) • Currents form large circular patterns: gyres • N. Pacific Gyre • N. Atlantic Gyre • S. Atlantic Gyre, • S. Pacific Gyre • Indian ocean Gyre

22. Pacific Garbage Patch • plastic and other marine debris in the north pacific gyre • Convergence zone • Majority is broken down plastic

23. Oceanic Currents

24. Surface Current Examples • The Loop Current • Current loops into the Gulf of Mexico • Curves around the southern tip of Florida (Florida Current) • When Florida Current mixes with Antilles Current • Gulf Stream • Picks up speed off of North Carolina

25. BP’s Oil spill & current • May 2010- what happens if the oil enters the loop current?? • Florida Keys & Coral Reef • August 2010- • The well is capped

26. Florida Gulf Stream • The Gulf Stream • Fast-moving, pulls warm water toward the N. pole • Gulf Stream moves at 5 mph & is about 45 mi wide • Warms European subcontinent • Notice the latitude of London is equal with N. Canada

27. What do these two things have to do with ocean currents? Explain Garbage Pacific Patch BP oil spill • http://www.youtube.com/watch?v=VT4GUhWMjog • (7 min 39 sec) • http://www.youtube.com/watch?v=IxgbvDcmrYQ • (3 min 45 sec)

28. "It's amazing what a duck can teach you." -Curt Ebbesmeyer, oceanographer

29. Questions • 1. What is ekman transport? • 2. Compare & Contrast Upwelling vs Downwelling • 3. Compare & Contrast El Nino & La Nina.

30. Ekman= net water movement • Upwelling • http://en.wikipedia.org/wiki/File:Upwelling_animated.gif • El nino • http://www.youtube.com/watch?v=UnbWa3E70zg&feature=related • http://alt.coxnewsweb.com/statesman/weather/elnino.swf

31. Upwelling & Downwelling • Vertical movements of water • Upwelling brings cold, nutrient-rich water up • Important for marine food webs • Increase phytoplankton population • Can affect climate • Downwelling • Water becomes denser & sinks

32. El Nino & Southern Oscillation • Southern Oscillation • Pressure systems in the Pacific Ocean change every 3-8 years • Causes trade winds to slacken or reverse • El Nino- the warming phase • Water normally pulled westward “sloshes” back toward the east • Upwelling slows (downwelling starts to occur) • Fisheries suffer • Dry areas see more rain

33. Normal Conditions vs. ENSO Conditions • El Nino • Reduced upwelling • Warmer waters

34. La Nina-the cooling phase • Normal conditions return with more intensity than usual.

35. Thermohaline Circulation • Surface currents join deep currents in areas of upwelling and downwelling • Creates one massive water cycle driven by temperature & density differences • Importance? • Transportation of heat, dissolved gases, solids, nutrients, juvenile organisms

36. Studying Currents • Float Method • Measures rate or direction of flow by watching movement of a drift bottle • Flow Method • Current is measured as it flows past a fixed object

37. Garbage Patch Vortex video • http://www.youtube.com/watch?v=VT4GUhWMjog

38. Pacific Garbage Patch • plastic and other marine debris in the north pacific gyre • Convergence zone • Majority is broken down plastic

40. “Today’s problems cannot be solved if we still think the way we thought when we created them.”-Albert Einstein • Garbage Patch Videos • http://www.youtube.com/watch?v=z7rNYzSH-BA&NR=1 • http://www.youtube.com/watch?v=tnUjTHB1lvM&feature=related • http://www.treehugger.com/galleries/2009/05/great-pacific-garbage-patch.php?page=1 • http://www.vbs.tv/watch/toxic/garbage-island-1-of-3 • Garabage Island: part 1, 2, & 3