1. Patterns in Time of Extreme Tides and Sea Level Rise over The 21 st Century: Puget Sound and the Other Marine Waters of Washington State Harold O. Mofjeld JISAO Senior Fellow and UW/Oceanography Affiliate Professor

2. Focus of the Talk: Marine Waters of Washington State 21st Century Tides and Sea Level Rise Providing the Best Available Science Marine Waters of Washington State 21st Century Tides and Sea Level Rise Providing the Best Available Science

3. Reporting Results of a Pilot Study to: Provide initial scientific results and insights Identify next steps to improve the science and make it available to those who need it Provide initial scientific results and insights Identify next steps to improve the science and make it available to those who need it

4. Complementary to Ongoing Work by the Climate Impacts Group, e.g.: Mote et al. (2008) on sea level rise in Washington’s marine waters Petersen (2007) Masters thesis on providing useful information to governments and agencies in the region Doug Canning’s work on sea level rise and fieldwork on high waters Mote et al. (2008) on sea level rise in Washington’s marine waters Petersen (2007) Masters thesis on providing useful information to governments and agencies in the region Doug Canning’s work on sea level rise and fieldwork on high waters

5. Some Stakeholders: Counties, cities, and towns Local, state and federal planning and regulatory agencies Property owners and investors Interest groups Public Counties, cities, and towns Local, state and federal planning and regulatory agencies Property owners and investors Interest groups Public

6. Approach: Compute tidal predictions at long- term tide stations Add Mote et al. (2008) sea level rise scenarios Look for patterns in the occurrences of extreme (high and low) water level events Compute tidal predictions at long- term tide stations Add Mote et al. (2008) sea level rise scenarios Look for patterns in the occurrences of extreme (high and low) water level events

7. REF.: TIDAL DATUMS AND THEIR APPLICATIONS NOAA Spec. Publ. NOS CO-OPS 1, 2000

8. Dividing WA Marine Waters into Four Regions: Puget Sound Eastern Straits Northwest Olympic Peninsula Outer & Southern Coast, Including Large Embayments Puget Sound Eastern Straits Northwest Olympic Peninsula Outer & Southern Coast, Including Large Embayments

9. Reference Tide Stations:

10. Examples of Coastal Types in the Four Tidal Regions WA Dept. of Ecology Shoreline Aerial Photos http://apps.ecy.wa.gov/shorephotos/

11. Seattle, Central Puget Sound Highly Developed Shoreline

12. Silverdale, Dyes Inlet Commercial and Private Development

13. Tahuya River Mouth, So. Hood Canal Private Shoreline Development, Habitat

14. Near Padilla Bay NER Reserve, Eastern Straits Shoreside Agricultural, Natural Habitat

15. Ocean Shores, Open Coast Developed, but with Dune Buffer

16. Cape Shoalwater, Open Coast Developed, but Possible Erosion

17. Observed Sea Level Trends at Reference Tide Gauges -- The Recent Past --

18. Elliott Bay, Seattle

19. Observed Mean Monthly Sea Level (MMSL) at Seattle

20. Friday Harbor -- San Juan Islands

21. Observed Friday Harbor MMSL

22. Neah Bay -- Olympic Peninsula

23. Example of a Tide Gauge -- Neah Bay

24. Observed MMSL at Neah Bay

25. Toke Point -- Outer Coast

26. Observed MMSL at Toke Point

27. Assumed Sea Level Rise Profiles for the 21st Century Based on Mote et al. (2008) Scenarios Relative to Mean Sea Level in 2000 Mote et al. (2008) values given for 2050 and 2100 Smooth curve (quadratic) fit through these values Allows for increasing upward trends toward the end of the 21st Century Relative to Mean Sea Level in 2000 Mote et al. (2008) values given for 2050 and 2100 Smooth curve (quadratic) fit through these values Allows for increasing upward trends toward the end of the 21st Century

28. Reference Tide Stations:

29. PUGET SOUND

30. NW PENINSULA

31. CENTRAL & SOUTHERN COAST

32. Predicted Tides For The 21st Century Looking for patterns in the high and low tides in their 18.6-yr cycle Noting that the tides vary significantly with location in the WA marine waters Sea level rise to be added later Looking for patterns in the high and low tides in their 18.6-yr cycle Noting that the tides vary significantly with location in the WA marine waters Sea level rise to be added later

33. Olympia -- Southern Puget Sound

34. Predicted Tides on May 12-13, 2008 -- Straits of JdF and Puget Sound

35. FOCUSING ON SEATTLE EXTREME PREDICTED TIDES: LOOKING AT HEIGHTS AND TIMING REFERENCE LEVEL FIXED AT MLLW FOR THE 1983-2001 TIDAL EPOCH

36. Seattle Tides (May-June 2008)

37. SEATTLE TIDE STATION: SAMPLE OF EXTREME PREDICTED TIDES

38. SEATTLE EXTREME PREDICTED TIDES

39. Nodal Variations of Tidal Amplitudes

40. SEATTLE HIGHEST PREDICTED TIDES

41. SEATTLE: HIGHEST PREDICTED TIDES

42. SEATTLE: TIMES OF HIGHEST PREDICTED TIDES

43. SUMMERWINTERSUMMERWINTER (UTC) (PDT)(PST) EARLIEST2:3214:215:32 PM6:21 AM AVERAGE3:4415:276:44 PM7:27 AM LATEST5:0416:368:04 PM8:36 AM RANGE (hr):2.532.242.532.24

44. SEATTLE LOWEST PREDICTED TIDES

45. SEATTLE: LOWEST PREDICTED TIDES

46. SEATTLE: TIMES OF LOWEST PREDICTED TIDES

47. SUMMERWINTERSUMMERWINTER (UTC) (PDT)(PST) EARLIEST18:196:259:19 AM10:25 PM AVERAGE19:037:0210:03 AM11:02 PM LATEST19:487:4110:48 AM11:41 PM RANGE (hr): 1.471.261.471.26

48. SEATTLE TIDAL DATUMS (Without Sea Level Rise)

49. Adding Sea Level Rise To The Extreme Predicted Tides At Seattle

50. PUGET SOUND

51. SEATTLE HIGHEST PREDICTED TIDES

52. SEATTLE LOWEST PREDICTED TIDES

53. Extreme Predicted Tides at Seattle: 21st Century with Very High Sea Level Rise (SLR per Mote et al., 2008, for Puget Sound)

54. LOOKING AT THE OTHER TIDAL REGIONS Eastern Straits (Friday Harbor) NW Olympic Peninsula (Neah Bay) Central & Southern Coast (Toke Point) Eastern Straits (Friday Harbor) NW Olympic Peninsula (Neah Bay) Central & Southern Coast (Toke Point)

55. Reference Tide Stations:

56. FRIDAY HARBOR EXTREME TIDES

57. PUGET SOUND

58. NEAH BAY EXTREME TIDES

59. NW PENINSULA

60. TOKE POINT EXTREME TIDES

61. CENTRAL & SOUTHERN COAST

62. Pilot Study for Washington’s Marine Waters: Summary of Results The extreme predicted high tides show very little variation during 18.6-yr nodal cycles, except in the Eastern Straits Hence, they tend to track sea level rise closely Note that ENSO and other interannual variations will be important for potential coastal flooding The extreme predicted high tides show very little variation during 18.6-yr nodal cycles, except in the Eastern Straits Hence, they tend to track sea level rise closely Note that ENSO and other interannual variations will be important for potential coastal flooding

63. Pilot Study for Washington’s Marine Waters: Summary of Results The extreme predicted low tides show more variation during 18.6-yr nodal cycles, with some regional differences There will be periods in the next decades when nodal variations in the tides can mimic apparent sea level rise effects on low tides that may occur much later in the 21st Century The extreme predicted low tides show more variation during 18.6-yr nodal cycles, with some regional differences There will be periods in the next decades when nodal variations in the tides can mimic apparent sea level rise effects on low tides that may occur much later in the 21st Century

64. Pilot Study for Washington’s Marine Waters: Summary of Results The months of the year and the times of day when extreme tides occur change very little throughout the 21st Century Note that the reference levels (datums) for water levels will be adjusted periodically during the Century in response to sea level rise The months of the year and the times of day when extreme tides occur change very little throughout the 21st Century Note that the reference levels (datums) for water levels will be adjusted periodically during the Century in response to sea level rise

65. Predicting Water Level Patterns in Washington’s Marine Waters: SOME NEXT STEPS Use tidal models to extend the coverage of predicted tides from just the reference tide stations to any location in the marine waters Update regional sea level rise predictions as these become available, since these are evolving rapidly Include ENSO and other interannual variations, at least statistically, to better represent actual water levels Use tidal models to extend the coverage of predicted tides from just the reference tide stations to any location in the marine waters Update regional sea level rise predictions as these become available, since these are evolving rapidly Include ENSO and other interannual variations, at least statistically, to better represent actual water levels

66. Predicting Water Level Patterns in Washington’s Marine Waters: Some Next Steps Develop a set of tidal GIS products that can be used for planning purposes, augmenting CIG and WA Dept. of Ecology programs Publish results in appropriate forms (e.g., websites, reports, articles, …) Encourage scientific community to take advantage of upcoming tidal variations in field and modeling studies on marine effects of climate change Develop a set of tidal GIS products that can be used for planning purposes, augmenting CIG and WA Dept. of Ecology programs Publish results in appropriate forms (e.g., websites, reports, articles, …) Encourage scientific community to take advantage of upcoming tidal variations in field and modeling studies on marine effects of climate change

67. Patterns in Time of Extreme Tides and Sea Level Rise over The 21 st Century: Puget Sound and the Other Marine Waters of Washington State Harold O. Mofjeld JISAO Senior Fellow and UW/Oceanography Affiliate Professor