The Next Generation of Ocean Drifters – Autonomous Underwater Explorers

In an effort to plug gaps in knowledge about key ocean processes, the National Science Foundation (NSF)’s division of ocean sciences has awarded nearly $1 million to scientists at the Scripps Institution of Oceanography in La Jolla, Calif. The Scripps marine scientists will develop a new breed of ocean-probing instruments. Jules Jaffe and Peter Franks will spearhead an effort to design and deploy autonomous underwater explorers, or AUEs. AUEs will trace the fine details of oceanographic processes vital to tiny marine inhabitants.

While oceanographers have been skilled in detailing large-scale ocean processes, a need has emerged to zero in on functions unfolding at smaller scales. By defining localized currents, temperature, salinity, pressure and biological properties, AUEs will offer new and valuable information about a range of ocean phenomena.

“We’re seeing great success in the global use of ocean profiling floats to document large-scale circulation patterns and other physical and chemical attributes of the deep and open seas,” said Phillip Taylor of NSF’s division of ocean sciences. “These innovative AUEs will allow researchers to sample the environments of coastal regions as well, and to better understand how small organisms operate in the complex surroundings of the oceans.”

The miniature robots will aid in obtaining information needed for developing marine protected areas, determining critical nursery habitats for fish and other animals, tracking harmful algae blooms, and monitoring oil spills.

For marine protected areas, AUEs will help inform debates about the best areas for habitat protection. With harmful algal blooms and oil spills, the instruments can be deployed directly into outbreak patches to gauge how they develop and change over time. In the case of an airplane crash over the ocean, AUEs should be able to track currents to determine where among the wreckage a black box may be located.

“AUEs will fill in gaps between existing marine technologies,” said Jaffe. “They will provide a whole new kind of information.”

AUEs work through a system in which several soccer-ball-sized explorers are deployed with many tens–or even hundreds–of pint-sized explorers. Collectively, the entire “swarm” of AUEs will track ocean currents that organisms at a small-scale, such as tiny abalone larvae, for example, experience in the ocean.

“AUEs will give us information to figure out how small organisms survive, how they move in the ocean, and the physical dynamics they experience as they get around,” said Franks. “AUEs should improve ocean models and allow us to do a better job of following ‘the weather and climate of the ocean,’ as well as help us understand things like carbon fluxes.”

Franks, who conducts research on marine phytoplankton, says that “plankton are somewhat like the balloons of the ocean floating around out there. With AUEs, we’re trying to figure out how the ocean works at scales that matter to plankton.

“If we place 100 AUEs in the ocean and let them go, we’ll be able to look at how they move to get a sense of the physics driving current flows.”

During the pilot phase of the project, Jaffe and colleagues will build five to six of the soccer-ball-sized explorers and 20 of the smaller versions. An outreach component of the project will enlist school children in building and ultimately deploying AUEs.

In a related funding award, the researchers have also been given $1.5 million from NSF’s Cyber-Enabled Discovery and Innovation initiative to design and develop the systems necessary to control the movement of AUEs.

That aspect brings Jaffe and Franks together with researchers at the Cymer Center for Control Systems and Dynamics at the University of California at San Diego’s Jacobs School of Engineering and the San Diego Supercomputer Center.

-NSF-

http://www.nsf.gov/news/news_summ.jsp?org=NSF&cntn_id=115887&preview=false

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Drifter Newsletter #3

November 2009

Satellite Account Setup

Our satellite service-provider has recently instituted a new policy.  Those of you  who get billed directly (or plan to get billed directly in the future) now need to fill out a one-time “business agreement form”. If you haven’t already done so and you plan to deploy drifters in 2010, please let me know. I will email a copy of this form partially filled out for you to fax or email to ComTech Inc.

Note: Those of you funded by the MATE project do not have to worry about this until your “message count” exceeds a few thousand. You can see your message count on the 8th column of the sensservice.com spreadsheet.

New Drifter Designs

Two new designs were tested in November 2009:

  • “Kathleen” Bucket

Dan McDonald and his crew from UMASS Dartmouth successfully deployed 26 bucket drifters off the mouth of the Merrimack River (Newburyport, MA) on Nov 7th after a large runoff event. All units, many of them fitted with additional sensors (temp, salinity, GPS, high-powered strobes), worked well and were successfully recovered after being quickly expelled into the open ocean. See figures below with stacked buckets and their tracks on the ocean.

SMCC-built bucket drifters stacked in the lab. The buckets float upside-down with only an inch or two above the waterline.

SMCC-built bucket drifters stacked in the lab. The buckets float upside-down with only an inch or two above the waterline.

UMASS Dartmouth Nov 2009 River Plume Study

UMASS Dartmouth Nov 2009 River Plume Study

  • “Ruben” Radio-tracked

I spent an afternoon on Buzzards Bay with Ruben Davis of Datissystems Inc of Catamet, MA a few weeks ago. Ruben, a retired electronic engineer, has devised a radio-tracked GPS drifter that can be monitored from a laptop on board or at a base station ashore. He demonstrated the successful operation of his prototype and plans to work on expanding the range capabilities of these units this winter. So, those of you interested in near-shore applications that are free of satellite costs, let me know.

Viewing Tracks in GoogleEarth

Some of you had trouble accessing and viewing the kml files. They are linked from the www.nefsc.noaa.gov/drifter site under the “drogue depth” column of the 2nd table. Please note that the best way to do this is to click on the link and then “viewèpage source” on the upper toolbar of your browser. This is the file you input to GoogleEarth. If your track does not have a kml file linked, or you have trouble viewing it, call  my cell at 508-566-4080 or email james.manning@noaa.gov .

Buoy sticks and toggle supplies

Some of you have had trouble obtaining more drifter parts that are NOT sold in most hardware/marinas. The buoy sticks and toggles (ie flotation component attached to the end of the fiberglass spars), for example, are sold specifically in Maine for the lobster and herring fishermen, respectively.  For help in obtaining these parts, you may contact erin@gomlf.org.

Proposals in the works

We have two proposals in the works that include drifter deployments. One is a small part of the Northeast Regional Associations of Coastal Ocean Observing Systems (NERACOOS) request to the 2010 NOAA IOOS. While we do not have much hope that it will be funded, we have nevertheless suggested routine deployments by fishermen at selected sites around the Gulf of Maine throughout the HAB season (Apr-Sep). Another proposal, in the early stages of development, is a follow-up to the eMOLT project in 2004 where, similar to the NERACOOS objective, lobstermen deploy student-made instrumentation around the Northeast region to obtain data for the purposes of validating numerical simulations. If any of you are interested in similar proposals in your region, let me know. I’ll send you a copy. If you have other ideas for drifter proposals, let’s hear them!

Drifter-related books

For an entertaining read about things that float in the ocean look up “Flotsametrics and the floating world”.  For more technical discussions on the science of things floating in the ocean see “Lagrangian Analysis and Prediction of Coastal and Ocean Dynamics”.

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CFCC Deploys 2 Drifters Off NC Coast

Jacqui and I have been working on ways to incorporate the tracks of the drifters into the program and coming up with some great ideas.

I just sent out a P.O. to purchase 2 more transmitters and around 2000 transmissions, so next year we will be ready!

 

 

Pictures are out of order. Will do better on second post!

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Drifter Newsletter #2

October 2009

Urethane Foam

There has been some discussion about what  “2-part marine urethane foam” to use when filling the PVC pipe. While SMCC suggests “Poly-U-Foam” (available on line for about $40/quart), there are probably other types in smaller qquantities that will do the job.  US Composites sells a “4-lb kit” for about $20 (catalog # “FOAM-0204”).  In fact, as Jason Hyatt (Mass Maritime) suggest, we MAY be able to get by with a can of “Great Stuff” from your local hardware but we do not know yet how well this will hold up in seawater.  Note that we did not use any foam at all for the first few years we deployed drifters. We only added this extra buoyancy within the pipe in hopes that the transmitter stays afloat  despite the inevitable loss of the other flotation.

MATE Drifter Blog

Thanks to our colleagues at MATE, you can follow a blog of drifter experiences at: http://coseenow.net/mate/ .  To make an entry in the blog, click on the “Register” link , “Log in”, and blog away. Note that they already have a set of “categories” to choose from including, for example, “curriculum development”, “collaborating with scientists”, etc. Under the “resources” page, there is a link back to the various SMCC/GoMLF/NOAA effort. I plan to enter this newsletter in their “Tracking the Drifter” blog.

Drifter Photos

We have compiled a gallery of drifter photos (linked from the bottom of the “drifter construction and technology” document at http://www.nefsc.noaa.gov/drifter/ ) and may harvest some more from the blog. Please send your contributions to james.manning@noaa.gov (or upload them to the blog) and supply the photographer’s name so that we can give the proper credit.

Tracks of the Month

There are always particular tracks that stands out from the rest. This month, the Cape Fear Community College drifters have provided some interesting tracks.  Their first drifter that was deployed just a few weeks ago has traveled over 2000 kilometers in the Gulf Stream but, even more amazing,   their 2nd drifter traveled over  hundred kilometers in one direction, turned around and came directly back nearly to where it started. CFCC is now working on building more drifters and some of the students are designing a wooden (ie biodegradable) drifter!

New Drifter Designs

Two new-style drifters will be deployed within the next few weeks. One is the “Kathleen” bucket drifter  which will track the very-near surface waters of the Merrimack River Plume for Dr. Dan McDonald of UMASS Dartmouth. Many of these units have powerful strobes, Garmin receivers, temperature and salinity sensors installed along with the TrackPacks.  There will be a total of 27 units deployed at the river mouth during an outgoing tide after a large runoff event. Stay tuned.

The other new style drifter, developed recently by Ruben Davis of  DatisSystems of N. Falmouth, MA, eliminates the need for satellite transmissions by implementing a radio-based system for near-shore high resolution applications. Stay tuned for the result of these prototypes.

TrackStick GPS receiver

Jason Goldstein and Win Watson (UNH) have come across the TrackStick.  Google this and you will see a compact device that may be a nice alternative to the Garmin units (for internal storage of fixes) and apparently provides more battery life.

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A Drifter Lab Exercise

Our Vice president of Academic Affairs asked me the other day if the tsunami affected the motion of the drifters here in Monterey Bay. “Voile!” I thought, what a great idea for a lab. If our vice president thinks that the tsunami might have affected the drifters, then our students must have the same question. So I developed the lab linked below.

I developed the lab to generate interest in the motion of the drifters. My students started on this lab on Monday and will finish it today. What I’m realizing is that perhaps the main benefit will be that in order to understand why the tsunami did not affect the motion of the drifters, the students will have to internalize how waves move about in the ocean, that it is not the flow of water parcels, but rather the water parcels interacting with each other to cause a wave. Ships out at sea are not affected by tsunamis, and neither are our drifters.

A Word format of the lab is available here:
http://www.mpcfaculty.net/alfred_hochstaedter/ocean/lab/DrifterTsunami.doc

 It is also available on the MPC Oceanography website:
http://www.mpcfaculty.net/alfred_hochstaedter/oceanography.htm

-Fred

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Ever Feel Like You’re Just Drifting in Circles


The MPC Drifters are back in the water this week as our MBARI collaboration continues for a second week. The data on the image above represents about 27 hours of data, from the afternoon of October 5 to about 6 pm local time of October 6. It illustrates quite nicely the 24-hour periodicity that is evident in much of our data. We have semi-diurnal tides here on the coast of California, so that pattern is not tidal. The drifters tend to have a stronger SE component of motion in the afternoons and a stronger NW component of motion in the early morning hours.

I’m trying to get some images of students deploying and retrieving the drifters. I’ll post them as soon as I get them.

-Fred

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MPC Drifters Retrieved!

A couple of MPC Oceanography students accompanied the MBARI team to recover the drifters yesterday. They quickly found both of them and brought them back on board. They were out for almost exactly 48 hours. After drifting south for the first 12 hours or so, perhaps due to strong NW winds that day, they turned and drifted north and west, along the expected counterclockwise rotation of surface water in Monterey Bay.

Here is a quick and dirty cut and paste job of their complete paths. I don’t have the software set up yet to make my own maps of their paths. These are from the AeroStar tracking website. They generally drifted from southeast to northwest.

We’re very happy with this first deployment of the drifters and thank the MBARI team of John Ryan and Erick Rienecker. The MPC students seemed to enjoy it as well. Four of the five we sent came back very enthused about the whole experience. They took some pictures, but I haven’t been able to get their pics downloaded onto my computer. Maybe we’ll see some next week.

So I’m thinking about how to integrate this stuff into my lesson plans for next week. I’m thinking of creating a short activity where we ask the question, “Did the tsunami affect the movement of the drifters?” This will involve the following aspects of data manipulation:

  • Determining the time the Tsunami hit Monterey
  • Making a hypothesis about whether or not the tsunami affected the drift
  • Identifying exactly what we would see, and on what timescale, if the tsunami affected motion.
  • Manipulating the Aerostar tracking site to find times and positions of data points
  • Looking at the data to determine if the identified changes in motion did or did not take place.

The anticipated outcome is that the tsunami did not, in fact, influence the movement of the drifters. Hopefully, this will be a useful realization that wave motion and current motion can be totally different because they are totally different processes. We know, for example, in the northeastern part of Monterey Bay that the longshore drift of the sand on the beaches is in exactly the opposite direction (west and southwest towards Moss Landing) than the surface currents (north and west, as our drifters demonstrated). So it would follow that tsunami motion would not necessarily be detected, especially at the temporal resolution available to the drifters (one measurement every half hour).

I’ll share this if I get it going.

Over and out.

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Serendipity Strikes the Drifter Project

Sometimes it seems like articles in newspapers are published as if they were planned to coincide with my syllabus. This was one such week. We set the drifters adrift on Tuesday and only two days earlier, on Sunday, the New York Times published a piece on surface currents in Monterey Bay, Finding Order in the Apparent Chaos of Currents.

The story has a big flashy graphic that decorated most of the cover of the Sunday Science section of the Times, and comes complete with an accompanying flash video and podcast. Click image for a larger, more readable version.

The article reveals how theoretical scientists are doing some pretty wild stuff with Lagrangian flow models and “Lagrangian coherent structures”. Now, I can barely pronounce “Langrangian”, much less explain it to my students, but there are fascinating revelations in all kinds of fields such as blood flow from ventricles, turbulence in atmospheric flow patterns, and, of course, dispersal of pollutants in the ocean currents.  On this image, the bright colors show the “amount of stretching and chaotic stirring in surface water”. I’m OK with the chaotic stirring, but stretching? Every semester I explain to my oceanography class about the incompressibility of water is the basis of hydraulic brakes working properly. Now I have to explain that water gets stretched somehow? Maybe now that you have taken the time to read this can explain this one to me.

 In any case, the article is very cool, even though I still don’t get a real, physical feel for how water circulates through the bay. It’s a different way of looking at flow with which I have no experience.

 I haven’t decided yet whether to ask my students to read this article. What do you think?

 Drifters come out of the bay today. More on that later.

 -Fred

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Drifters survive a tsunami on their maiden voyage


This is what the path of one of the drifters looks like today, approximately 24 hours after deployment. Remember yesterday, the drifter was taking a southerly route. Today, the drifters have turned northwards. Today is not as windy as yesterday.


This is what the other drifter path looks like today. It has also turned north after drifting south the first day. This one may have drifted further south the first day because it was deployed closer to the Salinas Valley, where the onshore winds are strongest. Well, maybe.


Here’s what the winds look like today. You can definitely see that the wind speeds are lower today, especially in the northeast portion of the bay where the drifters were deployed.

We had a bit of a distraction today with the Samoan earthquake and tsunami. The tsunami made it all the way to Monterey by yesterday evening, although its amplitude was only a few centimeters by the time it made it here.


In the image above (click on it for a larger image), you can see that the tsunami entered Monterey Bay at just past 0400 on Day 273, which is Sept 30, 2009. I guess we can say that the drifters survived a tsunami on their maiden voyage.

I just got word from the MBARI guys that the drifters will be recovered tomorrow. We’ll be sending a few more students on the cruise with them.

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The drifters are adrift here in Monterey Bay

Well, the drifters are adrift here in Monterey Bay. They were deployed mid day today, local time by a team from the Monterey Bay Aquarium Research Institute (MBARI) and three Oceanography students from Monterey Peninsula College. The study is part of an intensive effort to look at the physical oceanography associated with harmful algal blooms (HABs) After four messages to the satellite (configured at 48/day), the image looks like this:

 You can see two drifters are out there; the single position is from when the ship was on the way to deployment. Both of the drifters are drifting south or southeast. This is somewhat unexpected as we thought the circulation in Monterey Bay was counterclockwise as I explained in my previous blog.

Wonder why the drifters are drifting southsouthwest? They are moving directly towards the Salinas Valley, probably as a result of seabreezes that pick up every afternoon here. At least that’s my current (ha ha) hypothesis. The winds today are shown on the image above, blowing straight towards the Salinas Valley, which is between Moss Landing and Del Monte Beach on the image above. The drifters were deployed northeast of Moss Landing, somewhat north of the MO buoy as shown on the image above.

 Follow along at the usual spots. I’ll share the response of the students in a later installment.

 Over and out for now,

 -Fred

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