Daily Archives: September 16, 2017

Chasing vorticity off Oceano

The Inner Shelf armada is conducting synchronized along shelf lines off Oceano. Here’s a shot of R/Vs Kalipi and Sounder inshore of Oceanus. They were soon joined by Sally Ann shoreward of Sounder. On the offshore side was Sally Ride. Oceanus’ radar shows the 5 vessels all in a row headed north. The ADCP from Oceanus shows some nice upwelling, with southward flow at both depths and offshore at the surface with onshore at depth. Anyone see eddies in those plots? Thanks to Steve Pierce for the ADCP plots. And thank you V. Walfrid Ekman for the wind-driven flows. Oceanus successfully slalomed through some SWIFT and SIO drifters as they were transported offshore by the Ekman transport. The final shot is of our intrepid Oceanus science team, all 8 of us doing 12-hour shifts of 4 each.

From left to right: Raelynn Heinitz (OSU undergrad, Env. Sci), Mei Sato (OSU postdoc, bioacoustics), Marnie Jo Zirbel (OSU faculty research assistant), Jacqueline (Jack) McSweeney (sitting, OSU postdoc), Jack Barth (OSU), Lisa Nyman (UMiami grad student, marine Doppler radar), Johannes Becherer (OSU postdoc, microstructure) and Steve Pierce (OSU research associate).

 

Dissipation around Pt Sal

Here’s a quick work up of the SWIFT drifts around Pt Sal from the previous few days.  The drifts are all southwards (releases are at the northernmost points for each track), and the color scale is the log10 of the TKE dissipation rate averaged over the upper 5 m.  Looks like there is a region of high dissipation were the flow separates around the headland and changes direction.

Dissipation rates from SWIFTs drifting past Pt Sal

SIO Airborne Flight (9/15/17)

Today the SIO Melville lab had a successful 4.5 hour flight. There were no clouds on site for the duration of the flight and the wind picked up for good wave measurements with the lidar. The flight track included multiple high altitude alongshore passes to capture an overview of the area as well as nine separate cross shore legs at lower altitudes to measure the variation in the wave field throughout the experiment site. An additional calibration flight was also flown in the late afternoon. Click on images for full size.


L to R: Looking South from above Point Sal toward Point Purisima, looking North from above Point Sal toward Oceano, wind and wave conditions offshore from Point Sal.

Bring on the wind!

What a difference a day makes. Here’s a photo of a CTD launch on Oceanus this morning (9/15) giving data as we pass through these internal waves visible on the echosounder

The vertical profiles show two groupings, as the internal waves heave the thermocline up and down.

With some clever changes in the plotting scale, you can make fun patterns like this 🙂

This afternoon the winds picked up to over 30 knots and the ocean started looking like the California Current is supposed to look!

We’re presently sampling side-by-side with the Sally Ride on alongshore legs between the Oceano array moorings, mapping out the vorticity field and waiting for the non-linear bore arrival. We’ll measure the velocity and density fields as the ocean gets a shove from these strong winds.

—Jack Barth and the R/V Oceanus team

scripps oceanography uc san diego