Day 1 of SIO (Feddersen/Guza) deployments

Today was the first day of the SIO Feddersen/Guza deployments.   We installed all the pipes to mount Nortek Vectors, EcoTripplets, and marker poles at five locations denoted V1, V2, V3, V7, & V8.    For reference see the deployment map below.   The vector locations are labeled.     The idea is to be able to measure the dye dilution as dye is carried alongshore up and downcoast from the inlet – and the ADV current meters are to measure fluxes.     It is unlikely that there will be a strong tidal jet carrying tracer far offshore.   In our two test dye deployments the dye just went along the coast essentially.

Next up on Wed is 3 tripods at locations V4, V5, and V6.  These we’ll need the help of the LARC.    In the meantime  WHOI (Raubenheimer/Elgar) are cruising with their deployments and UNH has 2/3 ADCPs deployed.    Things are cooking!

 

Tidal elevation and currents: progressive or standing?

Inlet goons:

We deployed a current meter for 24 hours near the mouth of the inlet, just offshore of the
access road (where UW is building a condo complex out of pipes).

The currents  are close to in-phase with the tides. High tide=strong  flood, low tide=strong ebb. Slack is 90-degrees out of phase relative to a sinusoid, and thus slack is about 3 hours after high or low tide. The plot shows this.

The green dots are the pressure in dbars (close to m), so about a 1.2 m tide range on April 20-21, 2012. The blue dots are the currents along the channel (major axis) (1.25 m/s ebb (at low tide) and 0.8 m/s flood (at high tide)).

For this 24 hr period, max flood was maybe 1/2 hr before high tide, max ebb was maybe 1/2 hr before low tide.

Yesterday (April 23) the ebb was almost 3 knots (1.5 m/s) up the channel a km or so (around the bend) (drifting boats with GPS). Our marker floats were pulled under and we could not see them until the flow slowed way down! These are interesting conditions in which to work. The divers are tough as nails and a little bit insane, so they are getting the job done.

[Plot by Sean Kilgallin and Seth Zippel, data provided by Britt Raubenheimer, CAR-E, Danik, Jenna, Levi, Regina, David drove boats and hauled lines and heavy frames up and down in wicked currents.]