patterns in time of extreme tides and sea level rise over the 21 st century: puget sound and the...
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Patterns in Time of Extreme Tides and Sea Level Rise over The 21st
Century:Puget Sound and the Other Marine
Waters of Washington State
Patterns in Time of Extreme Tides and Sea Level Rise over The 21st
Century:Puget Sound and the Other Marine
Waters of Washington State
Harold O. MofjeldJISAO Senior Fellow
and UW/Oceanography Affiliate Professor
Focus of the Talk: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
Reporting Results of a Pilot Study to: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
Complementary to Ongoing Work by the Climate Impacts Group, e.g.:
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
Some Stakeholders: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
Approach: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
REF.: TIDAL DATUMS AND THEIR APPLICATIONS NOAA Spec. Publ. NOS CO-OPS 1, 2000
REF.: TIDAL DATUMS AND THEIR APPLICATIONS NOAA Spec. Publ. NOS CO-OPS 1, 2000
Dividing WA Marine Waters into Four Regions: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
Examples of Coastal Types in the Four Tidal Regions
Examples of Coastal Types in the Four Tidal Regions
WA Dept. of Ecology Shoreline Aerial Photos
http://apps.ecy.wa.gov/shorephotos/
Seattle, Central Puget SoundHighly Developed Shoreline
Seattle, Central Puget SoundHighly Developed Shoreline
Silverdale, Dyes InletCommercial and Private Development
Silverdale, Dyes InletCommercial and Private Development
Tahuya River Mouth, So. Hood CanalPrivate Shoreline Development, HabitatTahuya River Mouth, So. Hood Canal
Private Shoreline Development, Habitat
Near Padilla Bay NER Reserve, Eastern StraitsShoreside Agricultural, Natural Habitat
Near Padilla Bay NER Reserve, Eastern StraitsShoreside Agricultural, Natural Habitat
Ocean Shores, Open CoastDeveloped, but with Dune Buffer
Ocean Shores, Open CoastDeveloped, but with Dune Buffer
Cape Shoalwater, Open Coast Developed, but Possible ErosionCape Shoalwater, Open Coast
Developed, but Possible Erosion
Observed Sea Level Trends at Reference Tide Gauges
-- The Recent Past --
Observed Sea Level Trends at Reference Tide Gauges
-- The Recent Past --
Assumed Sea Level Rise Profiles for the 21st Century Based on Mote et al. (2008) ScenariosAssumed 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
Predicted Tides For The 21st CenturyPredicted 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
Predicted Tides on May 12-13, 2008 -- Straits of JdF and Puget Sound
Predicted Tides on May 12-13, 2008 -- Straits of JdF and Puget Sound
FOCUSING ON SEATTLE EXTREME PREDICTED TIDES:
LOOKING AT HEIGHTS AND TIMING
REFERENCE LEVEL FIXED AT MLLW FOR THE 1983-2001 TIDAL EPOCH
FOCUSING ON SEATTLE EXTREME PREDICTED TIDES:
LOOKING AT HEIGHTS AND TIMING
REFERENCE LEVEL FIXED AT MLLW FOR THE 1983-2001 TIDAL EPOCH
SEATTLE TIDE STATION: SAMPLE OF
EXTREME PREDICTED TIDES SEATTLE TIDE STATION: SAMPLE OF
EXTREME PREDICTED TIDES
SEATTLE: TIMES OF HIGHEST PREDICTED TIDESSEATTLE: TIMES OF HIGHEST PREDICTED TIDES
SUMMER WINTER SUMMER WINTER
(UTC) (UTC) (PDT) (PST)
EARLIEST 2:32 14:21 5:32 PM 6:21 AM
AVERAGE 3:44 15:27 6:44 PM 7:27 AM
LATEST 5:04 16:36 8:04 PM 8:36 AM
RANGE (hr): 2.53 2.24 2.53 2.24
SEATTLE: TIMES OF LOWEST PREDICTED TIDES SEATTLE: TIMES OF LOWEST PREDICTED TIDES
SUMMER WINTER SUMMER WINTER
(UTC) (UTC) (PDT) (PST)
EARLIEST 18:19 6:25 9:19 AM 10:25 PM
AVERAGE 19:03 7:02 10:03 AM 11:02 PM
LATEST 19:48 7:41 10:48 AM 11:41 PM
RANGE (hr):
1.47 1.26 1.47 1.26
Adding Sea Level Rise To The Extreme Predicted Tides At Seattle
Adding Sea Level Rise To The Extreme Predicted Tides At Seattle
Extreme Predicted Tides at Seattle:21st Century with Very High Sea Level Rise (SLR per Mote et al., 2008, for Puget Sound)
Extreme Predicted Tides at Seattle:21st Century with Very High Sea Level Rise (SLR per Mote et al., 2008, for Puget Sound)
LOOKING AT THE OTHER TIDAL REGIONSLOOKING 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)
Pilot Study for Washington’s Marine Waters:
Summary of Results
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
Pilot Study for Washington’s Marine Waters:
Summary of Results
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
Pilot Study for Washington’s Marine Waters:
Summary of Results
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
Predicting Water Level Patterns in Washington’s Marine Waters:
SOME NEXT STEPS
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
Predicting Water Level Patterns in Washington’s Marine Waters:
Some Next Steps
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
Patterns in Time of Extreme Tides and Sea Level Rise over The 21st
Century:Puget Sound and the Other Marine
Waters of Washington State
Patterns in Time of Extreme Tides and Sea Level Rise over The 21st
Century:Puget Sound and the Other Marine
Waters of Washington State
Harold O. MofjeldJISAO Senior Fellow
and UW/Oceanography Affiliate Professor