I-COOL

Hey All,

Now 5 days into his new mission, Silbo is making some slow progress as he reluctantly leaves the sunny shores of Gran Canaria behind.

As we get back into the swing of things, we have been working on covering all of our bases: ocean models, bathymetry maps, battery plots and means of monitoring biofouling.

Silbo has covered roughly 100km in 5 days, however he is slowing down the further south we go.  This is due to an average northern flux that we are slowly entering, resulting in the gradual slowing we have seen.

ocean currents provided by Antonio Ramos and ULPGC

Real Time Ocean Forecasting System Sea Surface Height and Currents

As displayed in the two images above, I proposed to move the way point to the east to try and get us into more friendly currents.

It is crucial that we try and get back to the south east at first, as these northward currents persist for nearly the entire water column

Finally, Silbo has become the first glider to navigate both Arctic AND Antarctic Waters!

The image above is from Antonio Ramos, showing the temperature of the water at roughly 900m below the surface.  The purple and blue jets we are seeing are bands of Antarctic Intermediate Water that rises from the deep ocean in this region.

Force Wind Sea and Honor

Antonio & Nilsen

Hey all,

So after this mornings deployment, Silbo is now only a few kilometers south of Maspalomas, GC.  Due to the short distance traveled from shore, we are not quite yet in water deep enough to fly to a full 1000m, and so we are diving to about 300m until we hit the shelf.  Much like with Ru29's shelf crossing, Silbo will see a very steep drop off in which the bathymetry drops off 1000m to a depth of 1400m in just 4 km.

We have also begun to think about path planning as Silbo distances himself from shore.  To the south west, there is a strong warm core eddy swirling in a clockwise manner.  I suggested to the group that we shift the way point to the south east corner of the eddy, as to ride the eddy instead of fighting it.

Once we round the eddy, there is a very nice current flying to the south-west which we should try and catch on our way towards Cape Verde.

Force, Wind Sea and Honor

Hey All

Roughly an hour ago, Silbo was deployed once again as he pushes the limits and continues his mission from one pole to the other!

Now that he is in the water, Silbo will fight the currents as he makes his way from Gran Canaria, south to Cape Verde, and then across the equator to the coast of Brazil.

We will update again as we get an update from the team on board the deployment vessel.

Force Wind Sea & Honor

One of our "yellow submarines" is in the news http://t.co/o5YGVGWm

Hey All,

So after another long weekend, we are at the eve of Silbo's next deployment.  This time, the destination is Brazil.

After quite a few delays, Chris DeCollibus of TWR arrived in Gran Canaria and immediately met with Alvaro at PLOCAN to begin preparations for the deployment.

Among a number of issues to cover, they worked on ballasting, measuring the h-moment, replacing the membrane on the oil bladder, applying anti bio surfaces to the hulls, and upgrading the software.

One difficulty found while ballasting, is that there is not just one density Silbo will encounter on this journey.  He will by flying from 1025 to 1022 sigma units as he moves from the Canaries to Brazil.  To get the most accurate density readings, we drew data from the extensive argo buoy fleet along the proposed path we will take

As for the bio fouling, Silbo is now equipped with a single hull sheet sticker which causes the hull to be slick, preventing anything from latching on.  There is also a potential of a diaper cream of urethane based tape that will go over the seams in order to prevent growth on those surfaces.

Antonio also chimed in with his forecasts for the upcoming week, providing us with sea surface height, wind speed, and wave data for the area of deployment.

Wave Forecast for the next couple of days

Wind Forecast for the next few days

Sea Surface Height near the Canaries

From the forecasts that Antonio provided, the weather isn't too bad and only gets better as the week goes on.  Also we can clearly see that upon deployment, Silbo will begin his journey by riding the strong warm eddy to the south around in a clockwise fashion as he makes his way south towards Cape Verde.

Early this afternoon, deployment details were finalized and the last of the preparations were made.  At noon tomorrow (Canary Time +5 hrs from EST) our team will set sail from the southern shores of Gran Canaria on The Blue Spirit (pictured below) out of Pasito Blanco yacht club.

Chris and Alvaro will lead the deployment and get back to us with further details.

Force, Wind, Sea & Honor!

Nilsen & Antonio

Hey All,

So we had quite a hectic weekend...

Saturday afternoon I received an emergency call from Tina and Dave that 29 was in trouble.  On the previous Thursday, the RUDICS server went down, preventing 29 along with gliders nation wide to be unable to call their respective doc servers.  This resulted in the gliders all calling in to Teledyne's Doc Server as it was listed as a back up number.  Due to the overwhelming number of calls now flooding their lines, TWR's doc server went down as well.  All along, we had little to no contact with 29.  Even worse was that this occurred just as we crossed the shelf, making the crossing even more stressful than normal.

She was successful in making it across the shelf untouched by fisherman, boats or the rapidly changing bathymetry, however, once she entered the shallow waters of the NJ Shelf, she was still commanded to make her top inflections 50m from the surface while diving to roughly 60m.  Now the pump that 29 is equipped with is of course a deep pump meant to be most effective when diving to a full 1000m.  So when 29 was then commanded to fly in 1% of the expected range for the pump, 29 chewed through the remaining battery available.

Waiting until Tuesday as planned for 29's recovery was no longer an option especially with the weather becoming more severe as the week went on.  So we began preparing for an emergency recovery possibly that night.  After seeing what boats were available, we decided on Sea Tow's Cape Hatteras which was the vessel used for deployment.  However, the earliest doc time available was 5pm, and with there being easily a 3 hr ride out to 29, that would leave us searching for her in the dark.

The next option was a 7am doc time which we agreed upon, and at 3:45 am, Austin and I departed from IMCS in the Glider Van to meet Dave in Atlantic City and try and recover our glider.  Upon arrival, we boarded the ship and left the marina at the Golden Nugget.

After about 3 hrs we made it the 60 miles off shore to where 29 patiently waited.  We then ran a ctd cast to compare to the data collected by 29 while we waited for the most recent gps location.

Although sunny, there was a storm brewing and throughout the day the waves and wind gradually picked up.  We then received a new gps point and started to close in on the location while 29 did one last dive to compare to our ctd cast.

When we got to the latest position, 29 sprung up right next to us, surfacing no more than 20 ft from the ship.  We then prepared to pull her on board.

Dave laid down on the deck while Austin took position with the dog catcher, and I took control of the recovery cart.

After some skilled maneuvering, we were able to slide 29 on to the cart and pull her up on board the ship and secure her in the cart.

As we headed back home, our friends back on shore spread the word that the "bear is in the igloo," marking the success of the mission.

Click the link below to be redirected to the RuCool YouTube page and the recovery video for Ru 29!

RU29 Recovery Video

Hey all,

Over the past two and a half weeks, 29 has been put through a number of test missions in an attempt to see if she is suited for her long duration flight as she kicks off the Challenger Mission in the upcoming months.

First off, we set the limits for our testing area.  Where we crossed the shelf, we were dealt an area bound by two large warm eddies, one to our north and one to the south, the Gulf Stream to our east, and the New Jersey Shelf to our west.

The test path we chose was to run back and forth in our test bed parallel to the shelf.  However, before we even had a chance to start our test missions, we found our first anomaly.

As we approached the way point before our turn to the North West, 29 mysteriously turned to the south even though the current was pushing us directly at our way point.  After further investigation, we discovered that this was due to the gliders thought process.  What had happened was that Challenger got close enough to the way point that given the strength of the current, she thought that she was going to over shoot the way point while on her dive.  Because of this, 29 aimed itself in the opposite direction as to fight the current that was helping us, thus causing the turn to the south.

As for the tests, we started off with making sure she is capable of diving the full water column.  This is done by stepping down, or pushing the depth we dive to gradually down over the course of a number of segments:

Once we completed this, the next on our list was to do a spin test.  This test sets the fin to one side and holds it there for the entirety of the dive.

By keeping the fin stationary to one side, the glider is sent into a spin as it dives and climbs.  In theory, the glider should then go down and come back up in the same location, but due to currents, both surface and subsurface, we drift.  Then by comparing the drift to the gliders calculation of the currents, we can measure the accuracy of the gliders calculation for depth average currents.  After completing the test, we found the error to be a little over 20˚ which was deemed acceptable.

Next we looked into some of the engineering variables needed to optimize flight for the gliders.  This included adjustments made to the placement of the fin offset, dead band, and gain with various combinations of the three to see which settings would be optimal for our missions. A full listing of the tests and results can be found here.

Our final test was to see if we could successfully inflect at depth.  This was proposed a few times over the course of Silbo's flight from Iceland to the Canaries due to strong surface currents that were harmful while at depth the currents were more favorable.  So if we were able to make our top inflections at depth, we could minimize our time spent in the poorer conditions.

It was a success!  29 did two tests, one test with two dives between 100m and 400m, and a second test with dives between 200m and 400m.

Now that we accomplished a majority of what we wanted to test (also our batteries have run pretty low), we have set the way point back towards Atlantic City to try and cross the shelf before the weekend in preparation for a recovery early next week.