patterns in time of extreme tides and sea level rise over the 21 st century: puget sound and the...

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

Reference Tide Stations:Reference Tide Stations:

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 --

Elliott Bay, SeattleElliott Bay, Seattle

Observed Mean Monthly Sea Level (MMSL) at SeattleObserved Mean Monthly Sea Level (MMSL) at Seattle

Friday Harbor -- San Juan IslandsFriday Harbor -- San Juan Islands

Observed Friday Harbor MMSL Observed Friday Harbor MMSL

Neah Bay -- Olympic PeninsulaNeah Bay -- Olympic Peninsula

Example of a Tide Gauge -- Neah BayExample of a Tide Gauge -- Neah Bay

Observed MMSL at Neah BayObserved MMSL at Neah Bay

Toke Point -- Outer CoastToke Point -- Outer Coast

Observed MMSL at Toke PointObserved MMSL at Toke Point

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

PUGET SOUNDPUGET SOUND

NW PENINSULANW PENINSULA

CENTRAL & SOUTHERN COASTCENTRAL & SOUTHERN COAST

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

Olympia -- Southern Puget SoundOlympia -- Southern Puget Sound

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 Tides (May-June 2008)Seattle Tides (May-June 2008)

SEATTLE TIDE STATION: SAMPLE OF

EXTREME PREDICTED TIDES SEATTLE TIDE STATION: SAMPLE OF

EXTREME PREDICTED TIDES

SEATTLE EXTREME PREDICTED TIDESSEATTLE EXTREME PREDICTED TIDES

Nodal Variations of Tidal AmplitudesNodal Variations of Tidal Amplitudes

SEATTLE HIGHEST PREDICTED TIDESSEATTLE HIGHEST PREDICTED TIDES

SEATTLE: HIGHEST PREDICTED TIDESSEATTLE: HIGHEST PREDICTED TIDES

SEATTLE: TIMES OF HIGHEST PREDICTED TIDESSEATTLE: TIMES OF HIGHEST 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 LOWEST PREDICTED TIDESSEATTLE LOWEST PREDICTED TIDES

SEATTLE: LOWEST PREDICTED TIDESSEATTLE: LOWEST PREDICTED TIDES

SEATTLE: TIMES OF LOWEST PREDICTED TIDESSEATTLE: TIMES OF LOWEST PREDICTED TIDES

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

SEATTLE TIDAL DATUMS(Without Sea Level Rise)

SEATTLE TIDAL DATUMS(Without Sea Level Rise)

Adding Sea Level Rise To The Extreme Predicted Tides At Seattle

Adding Sea Level Rise To The Extreme Predicted Tides At Seattle

SEATTLE HIGHEST PREDICTED TIDESSEATTLE HIGHEST PREDICTED TIDES

SEATTLE LOWEST PREDICTED TIDESSEATTLE LOWEST PREDICTED TIDES

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)

FRIDAY HARBOR EXTREME TIDESFRIDAY HARBOR EXTREME TIDES

NEAH BAY EXTREME TIDESNEAH BAY EXTREME TIDES

NW PENINSULANW PENINSULA

TOKE POINT EXTREME TIDESTOKE POINT EXTREME TIDES

CENTRAL & SOUTHERN COASTCENTRAL & SOUTHERN COAST

Pilot Study for Washington’s Marine Waters:

Summary of Results


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


Summary of Results


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


Summary of Results


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


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


Some Next Steps


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







Harold O. MofjeldJISAO Senior Fellow

and UW/Oceanography Affiliate Professor

patterns in time of extreme tides and sea level rise over the 21 st century: puget sound and the...

Documents

seattle slide

govshorephotos slide

developed shoreline

sea level rise scenarios

large embayments slide

private development

groups public slide

natural habitat slide