2. Texas Flood Stevie Ray Vaughan Geosc040, Lecture 23. Tides: Sun, Moon, Rise and Fall Swimming With Sharks Hoodie Allen Swimming in the Flood, Passion Pit Feel The Tide Mumford And Sons Thanks to Mary C.

3. Quiz 2: On Apr. 13 OLA 11 Due today Homework 4 Due Apr. 19 Extra Credit Letters: I’m reading them now… Grades posted by Apr 20 Read about the ocean Review Sheet Linked on Course Web Site

4. Relay for Life is this weekend. Sat. April 9 th ! Cell phones will be accepted for relay for Life until Apr. 14 Apr 26 is the last day to report problems with your clickers and/or in-class activity credit. Check grade info. on Angel I will not make changes for problems with in-class activity credit reported after April 26

5. No Class meeting on April 21 or April 26: Read about the ocean! and study on-line materials. http://www3.geosc.psu.edu/Courses/Geosc040/Syllabus.html

6. http://vimeo.com/89868953 North Atlantic stock: spawn in Sargasso Sea then larvae migrate to freshwater

7. Spawning Behavior Catadromous vs. Anadromous Fishes Catadromous fishes migrate from freshwater to saltwater to spawn http://www.pc.gc.ca/eng/nature/eep-sar/itm3/eep-sar3aa/1.aspx

8. Waves and wind Using satellite data to track swells and heir relationship to wind ( storms)

9. Waves and wind Using satellite data to track swells and heir relationship to wind ( storms) JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY

11. http://journals.ametsoc.org/doi/pdf/10.1175/1520-0426(2002)019%3C1849%3AAGVOSA%3E2.0.CO%3B2

12. Waves Using satellite data to track swells and their relationship to wind ( storms) -The guys in Point Break would be interested!

13. Today’s Clicker Questions A.I will receive full credit for answering 80% or more of the questions B.I will receive no credit if I answer less than 80% of the questions C.If there are 10 questions and I answer at least 8 of them I’ll get full credit for today (100%); If I answer 7 or fewer questions, I will receive no credit for today. D.If I answer the question correctly I’ll get a bonus point, up to a maximum of 105% for today’s in-class exercise E.All of the above (this is the correct answer, choose E!)

14. My Job in Geosc040 100 Thomas is a big room. Talking is distracting to your neighbors… Wait for clicker questions Don’t chat during lecture slides

15. Origin of Tides Two Approaches 1)Equilibrium theory. Makes simplifying assumptions, provides a basic understanding of tides 2) Dynamic theory. Complexities of coastlines, bays, ocean basin geometry, Earth deformation.

16. Fig 10.13 Fig 10.14 Global Distribution of Tide Types Note dominance of Semidiurnal tides

17. Tidal Regimes Macrotidal Mont St. Michel, France

18. Why are there Two Tidal Bulges! -Gravity and Inertia (centrifugal force) Gravity Inertia

19. Why are there Two Tidal Bulges! -Gravity and Inertia (centrifugal force) http://www.fearofphysics.com/SunMoon/sunmoon1.html

20. Basic elements of tidal variation over one month

21. Note Asymmetry in highs and lows

22. A Higher High Tide Lower High Tide

23. Timing and Predictability of Tides Semidiurnal tides have a range that cycles over a 14 day period. This coincides with the moon’s 28 day orbital period. Monthly inequality Max semi-diurnal tides occur when spring tides coincide with lunar perigee. Predicting tides is difficult Factors to consider: lunar distance solar distance lunar declination solar apparent declination relative alignment of sun and moon coastal morphology location of amphidromic point must also take into account storms, wind patterns, etc.

24. Variations in tidal amplitude Moon’s orbit around Earth is elliptical (eccentricity ~0.055) Apogee (farthest ~0.40x10 6 km) Perigee (closest ~0.36x10 6 km) Apogee Perigee Difference (4 x10 4 km) is important because gravitational attraction is proportional to square of distance Declination of lunar orbit varies 28.5 degrees above and below equator during lunar month

25. Note that the Spring Tide during days 22 through 26 is bigger than the Spring Tide during days 6-8. Apogee Perigee Max semi-diurnal tides occur when spring tides coincide with lunar perigee. Moon’s orbit around Earth is elliptical Apogee (farthest ~0.40x10 6 km) Perigee (closest ~0.36x10 6 km)

26. Diurnal and semi-diurnal Variations in tidal amplitude

27. Your Job in Geosc040 100 Thomas is a big room. Talking is distracting to your neighbors… Wait for clicker questions Don’t chat during lecture slides

28. Origin of Tides Two Approaches 1)Equilibrium theory. Makes simplifying assumptions, provides a basic understanding of tides 2) Dynamic theory. Complexities of coastlines, bays, ocean basin geometry, Earth deformation.

29. Dynamic theory of Tides and Amphidromic points Continental margins and the Coriolis effect 1) Continents. As Earth spins the tidal bulges attempt to stay below the moon and opposite of it. Therefore water is forced against the continental margin. This occurs on the western margin of the ocean basin (eastern margin of continent)

30. Dynamic theory of Tides and Amphidromic points Continental margins and the Coriolis effect 1) Continents. As Earth spins the tidal bulges attempt to stay below the moon and opposite of it. Therefore water is forced against the continental margin. This occurs on the western margin of the ocean basin (eastern margin of continent) Tides are very long-wavelength shallow water waves. Tidal crests are separated by half of Earth’s circumference! Picture waves trapped in ocean basins between continents. 2) Coriolis. In the northern hemisphere, as water travels north it moves to the right and thus the Eastern side of the ocean basin. The opposite happens for water traveling south. This sets up a counterclockwise wave motion, with water sloshing back and forth in the ocean basins.

31. Dynamic theory of Tides and Amphidromic points 1) Continents. As Earth spins the tidal bulges attempt to stay below the moon and opposite of it. Therefore water is forced against the continental margin. This occurs on the western margin of the ocean basin (eastern margin of continent) Tides are very long-wavelength shallow water waves. Tidal crests are separated by half of Earth’s circumference! Picture waves trapped in ocean basins between continents.

32. Dynamic theory of Tides and Amphidromic points Continental margins and the Coriolis effect Development of Amphidromic Circulation https://www.youtube.com/watch?v=LRDoLDCiNeE

33. Dynamic theory of Tides and Amphidromic points Continental margins and the Coriolis effect Development of Amphidromic Circulation

34. Dynamic theory of Tides and Amphidromic points Continental margins and the Coriolis effect Development of Amphidromic Circulation

35. Dynamic theory of Tides and Amphidromic Circulation

36. https://www.youtube.com/watch?v=LRDoLDCiNeE High Tide

37. Dynamic theory of Tides and Amphidromic Circulation https://www.youtube.com/watch?v=LRDoLDCiNeE High Tide

38. Dynamic theory of Tides and Amphidromic Circulation https://www.youtube.com/watch?v=LRDoLDCiNeE High Tide

39. Dynamic theory of Tides and Amphidromic Circulation https://www.youtube.com/watch?v=LRDoLDCiNeE High Tide

40. Your Job in Geosc040 100 Thomas is a big room. Talking is distracting to your neighbors… Wait for clicker questions Don’t chat during lecture slides

41. Dynamic theory of Tides and Amphidromic Circulation High Tide

42. Dynamic theory of Tides and Amphidromic Circulation High Tide

43. Dynamic theory of Tides and Amphidromic Circulation High Tide

44. Dynamic theory of Tides and Amphidromic Circulation High Tide

45. Dynamic theory of Tides and Amphidromic Circulation High Tide

46. Dynamic theory of Tides and Amphidromic points Continental margins and the Coriolis effect Development of Amphidromic Circulation

47. Dynamic theory of Tides and Amphidromic Circulation High Tide

48. Dynamic theory of Tides and Amphidromic Circulation High Tide Coriolis deflects currents to the right in the N. Hemisphere

49. Amphidromic Circulation Tidal crests move in a counter-clockwise pattern around the basins of the northern hemisphere. Like Fig 10.17 Noon 3 pm 6 pm 9 pm

50. Development of Amphidromic Circulation Tidal crests move in a counter-clockwise pattern around the basins of the northern hemisphere. These rotary waves revolve around a fixed NODE (which experiences no tidal fluctuation-an amphidromic point). The resulting circulation is called an amphidromic system.

51. Amphidromic Circulation and Tides

52. Amphidromic Circulation These rotary waves revolve around a fixed NODE (which experiences no tidal fluctuation-an amphidromic point). The resulting circulation is called an amphidromic system. Tidal crests move in a counter-clockwise pattern around the basins of the northern hemisphere.

53. Development of Amphidromic Circulation Tidal crests move in a counter-clockwise pattern around the basins of the northern hemisphere. These rotary waves revolve around a fixed NODE (which experiences no tidal fluctuation-an amphidromic point). The resulting circulation is called an amphidromic system.

54. Amphidromic Circulation Earth has about 12 amphidromic systems Tidal amplitude increases progressively away from amphidromic points Fig 10.16

55. http://www.die.net/earth/hemisphere.html

56. Tides are shallow water waves, produced by gravity and inertial (centrifugal) forces A tide is a “ forced ” wave, and actually must travel very rapidly to keep up with the forcing (forcing is as fast as 1600 km/hr. at equator) Earth-Moon Rotation Axis REVIEW

57. Dynamic theory of Tides. Complexities of coastlines, bays, ocean basin geometry, Earth deformation.