The Epsilometer and the biological hotspots ...

In April 2018, a team of Scripps graduate students designed a 3 days experiment on the R/V Sproul in order to explore a biological hotspot south of San Clemente Island, only a few miles west of San Diego. This area is known to support large populations of demersal and pelagic fish, such as rockfish and tuna. While both the scientific and local fisheries communities are well aware of such biological productivity, little is known about the physical mechanisms that aid the high productivity at this site. The students proposed to investigate the flow in order to test several hypotheses and determine the physical mechanism that drives the elevated biological productivity.

In addition to the Del Mar mooring recovery and deployment of a WireWalker, the students tested new sensors developed by Scripps physical oceanographers Matthew Alford and Arnaud Le Boyer. Dubbed the epsilometer or “epsi,” the device uses advances in electronics borrowed from the cell phone industry to measure water turbulence (epsilon) in a low-cost, low-power manner. 🎥: Isabela Le Bras

Iceland cruise: survived

Team MOD successfully deployed two wire walkers, the fast CTD and two epsi-fish microstructure profilers in challenging conditions (up to 50 knot winds and 8-m seas) on R/V Armstrong.

We learned much about the generation of internal waves and the modulation of mixed-layer turbulence by the wind - and the effects of the wind on the ship and its scientists!

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8 cruises, 5 oceans

The MOD group has been working for what seems like months now to prepare our gear for 8 cruises in 5 different oceans: The Gulf of Mexico, The South China Sea, the Arctic, the Atlantic and the Indian Ocean.  We've now shipped 5 containers to various places and built several new systems that didn't exist before.  

We are tired.

And so far, things are going OK.

 

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New toys!

We had an incredibly successful test cruise of our new turbulence instrumentation last week.  The team worked tirelessly to get the epsilometer working, and to design the new "epsi-fastCTD" vehicle up and running.  All went well and now we can measure turbulence in several new, modular and flexible ways!

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Making a difference

MOD is inspired by Mai Bui, who wanted to help after hurricane Harvey and took the simple - but not easy - action of jumping on a plane and pitching in.  In addition to spending several days packing food and cleaning up, her group raised over $14,000 for the people of Houston.

You're amazing Mai!

 Mai Bui and coworkers bagging food in Houston.

Mai Bui and coworkers bagging food in Houston.

Epsilometer testing

 The epsi (short for epsilometer, as it measures the turbulent quantity epsilon) has two shear probes, two thermistors and accelerometers.

The epsi (short for epsilometer, as it measures the turbulent quantity epsilon) has two shear probes, two thermistors and accelerometers.

We are really making progress on the Navy-funded epsilometer!  It is now capable of streaming serial data or writing to compact flash, has a 1000-m pressure case, and can run for a couple of days on AA batteries.  We're beginning to put it on everything, including wire walkers and a newly designed fast CTD vehicle.  

 

We have a test early November on R/V Sproul and are hoping for excellent results.

Postdoc opportunity!

We are currently looking for a postdoc to work with us on the Samoan Passage project. Research tasks include analysis of a dense 3D dataset of moorings and tows resolving hydraulically controlled flows, breaking internal waves, turbulent mixing and other processes in the Samoan Passage, a constriction in the abyssal Pacific Ocean. In addition, we have results from a very high resolution numerical model of the region at hand to help with the analysis.

Click here to learn more

Inner Shelf extravaganza gets underway!

Scientists from ours and other groups at Scripps, as well as other institutions around the country, are gearing up for a major initiative to better understand the "inner shelf".  This is the region just offshore of the surf zone (yes that is the technical term) but still in the relatively shallow water of the coastal ocean.  This area is governed by unique but complex physical processes, including wind-driven circulation, upwelling, breaking waves, wakes and instabilities, and internal waves (that ride on density interfaces below the surface).  Funded by the Office of Naval Research, we will spend the next couple months observing and trying to detangle the complexities of this system using a combination of mooring and ship-based observations.  Befitting the complexities of this part of the ocean, we are attacking with with everything but the kitchen sink, including a staggering 119 moorings(!), 7 ships (!) working in concert, arrays of drifters, dedicated scientific aircraft surveys, and more.  We're just loading up gear right now, more details once we get underway!  https://scripps.ucsd.edu/projects/innershelf/readying-gear-on-the-rv-sally-ride/