1 / 11

Deep-water Intrusions in the Puget Sound

Deep-water Intrusions in the Puget Sound. Sally Warner Coastal & Estuarine Fluid Dynamics class Friday Harbor Labs Summer 2006. Project goals. Was an intrusion of dense ocean-water occurring during our 36-hour cruise? What processes were working to allow or prevent this intrusion?.

jolene-williamson
Download Presentation

Deep-water Intrusions in the Puget Sound

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Deep-water Intrusions in the Puget Sound Sally Warner Coastal & Estuarine Fluid Dynamics class Friday Harbor Labs Summer 2006

  2. Project goals Was an intrusion of dense ocean-water occurring during our 36-hour cruise? What processes were working to allow or prevent this intrusion?

  3. Estuary dynamics

  4. Fjord dynamics

  5. Intrusions Why are intrusions essential to fjords? What controls the onset of intrusions? What happens in the Puget Sound?

  6. Puget Sound and Admiralty Inlet depth

  7. The Intrusion 30.8 psu 30.8 psu water intruding down the estuary side of the sill

  8. Barotropic vs. Baroclinic Forcing Barotropic excursion distance 31.2 Tidal current t0 t1 t2 time Advection distance of 31.2 psu water: 3.89 and 4.03 km in 5.3 and 5.0 h. Barotropic excursion lengths: 0.95 and 1.60 km

  9. ADCP velocity ubarotropic = 27 cm s-1 ubaroclinic = 25 cm s-1 t3 Baroclinic circulation is essential for the propagation of the intrusion

  10. Historical Data: sx vs. mixing 38 historical transects and our cruise • “Bottom water renewal is controlled by changes in the intensity of mixing due to fortnightly variations in the tidal amplitude.” Geyer & Cannon (1982) • “The onset of intrusions is a result of the fluctuations in the horizontal density gradient caused by salinity variations across the sill.” Cannon et. al. (1990) Our cruise: slack = 14 h s = 1.5 psu, sx=0.03 psu km-1

  11. Conclusions • Yes, an intrusion was occurring when we visited Admiralty Inlet • Reduced tidal velocities allowed baroclinic circulation to develop which carried 30.8 psu water over the sill. • Both the spring/neap change in tidal energy and variation in the horizontal salinity gradient are important mechanisms controlling intrusions of deep water into the Puget Sound, as seen from historical data.

More Related