Post on 07-Jan-2016
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Puget Sound Oceanography• An introduction by Fritz
Stahr & Christian Sarason
• Outline – estuary definition
– examples - PS, SF Bay, Chesapeake
– tides & other cycles (view model runs)
– exercise with real data
An estuary is...A place where river(s) meets the ocean...
Where the Mississippi River meets the Gulf of
Mexico is not an estuary, though some
side drainage is.
that has surrounding land and a limited opening...
San Francisco Bay where the Central
Valley rivers meets the Pacific is an estuary.
An estuary is...A place where river(s) meet the ocean that has surrounding land and a limited opening...
and where the fresh and salt water mix.Puget Sound is an estuary; it is connected to the Pacific ocean through the Straits of Juan de Fuca.
U.S. Estuary ExamplesChesapeake Bay
Different bathymetry makes for different circulation and mixing
“Standard” deep mouth - e.g., Chesapeake, Tampa & SF Bay
With a sill - “fjord” - e.g., Puget Sound
Different river flow makes for different circulation and mixing
High river flow + weak tides = strong salt wedge
Low river flow + stong tides = well mixed
A quick reminder on tides in Puget Sound...
Each day there are two high and two low tides here, but they’re unequal...we call it “semi-diurnal mixed.”
Every other week, the “phase” or type of tidal range changes between “spring” - large differences between high and low- and “neap” - smaller differences. This plays a role in circulation within the Sound.
A quick reminder on tides in Puget Sound...
Predicitons for Seattle, WA 24 Feb 2004 - 21 Mar 2004
Let’s see some of this in Puget Sound via a
numerical model - courtesy of Mitsuhiro
Kawase, UW and Christian Sarason, OIP