Category: silbo (Page 11 of 22)

Hey All,

So Silbo puzzled us a number of times today, leaving us with a few questions we are still investigating and will update everyone on once we find the answers.

First off, when Silbo surfaced on the 12:03am on August 1, he mysteriously popped up in a very unexpected location:

He had flown backwards nearly a day and a half worth of progress, surfacing directly where he crossed on the 30th.

To add to the mystery, the last two surfacings have taken longer than normal, up to ~12 hrs between surfacings (up from 10.5 for the previous days).  These two issues will be further investigated by our team over the next couple days.

Looking at my rough vertical velocity plot below, we can see that the previous two surfacings show that our average velocity seems to be a bit lower than previous segments.  We will look further in depth soon to see if we can find out what may have caused this.

Finally, we do have a bit of good news!  The battery estimates below are showing that we potentially have enough battery power to last us through September 2013!

Silbo is currently equipped with 3 lithium battery packs, which makes these numbers believable.  Although it shouldn’t take us that long to complete our mission, it is a nice security blanket seeing those numbers

Force Wind Sea & Honor

Antonio & Nilsen

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

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 over the past couple days Antonio and I have been working on analyzing the biological growth that we found on Silbo upon recovery.  This began with the analysis of growth on another epic glider mission which preceded Silbo’s : The Trans Atlantic Crossing of Ru27, The Scarlet Knight.

Scarlet was at sea for 221 days covering 7400km on her crossing from New Jersey to Spain.  While on this journey, Scarlet became severely plagued by biological growth as populations of Goose neck barnacles latched on.  This produced a large amount of drag, similar to the flaps being extended on an air plane’s wings for breaking, which resulted in Scarlet’s velocity being reduced to 10%.  In the first image, we have a comparison between a time series of temperature across the Atlantic between NJ and Spain, compared with Scarlet’s velocity profiles.

In the velocity profiles, we see 3 distinct decreases in velocity, which when compared to temperature, we can conclude defines the presence of a new cohort’s existence.

The first cohort, which took hold pretty early on in the mission, took roughly 90 days to reduce the velocity to 10%.

On top of that, Scarlet then hit a strong heat signature which accelerated this decrease in velocity to nearly zero, leaving Scarlet to be nearly at the point of a drifter.  This only took about 12 days, meaning a jump in the growth of the first cohort, or the uprising of a second.  This resulted in an emergency excursion to the Azores by Rutgers technicians Chip and Tina where the barnacles were then washed off.

After Scarlet was cleaned off and returned to full throttle,  a new cohort latched on, but at this point being out of the main branch of the Gulf Stream,  the temperatures that fueled the growth were absent and it took the last 140 days of the mission to reduce Scarlet’s velocity once again.

From this information, Antonio applied the von Bertalanffy model to project our findings to apply to the growth we measured on Silbo upon recovery.

Another finding was that as long as the temperature is below 15˚C we will see no growth on the glider.

Combining what we had previously found, we then looked into the sizes of the barnacles found on Silbo compared with the temperatures along the way.

From the measurements we saw two cohorts, one about 8mm and one that was less than 2.

Then back tracking through Silbo’s mission to compare with the data and von Bertalanffy model, we concluded that the first cohort was from the very beginning of the mission while the second could only be about a few weeks old.

I then went back and plotted each dive from Silbo and found that at the beginning of the mission, Silbo spent about a day diving to 500m where the waters were relatively warm.  Then on March 12, it looks like we had an abort which led to Silbo sitting at the surface for at least half of a day.  This scenario mixed with warm temperatures and the productive waters associated with the islands led to conditions in which the barnacles were able to latch on and begin to grow.

Then later in the mission as Silbo was passing the island of Madeira, Silbo dropped a call and spent nearly a day sitting at the surface on May 4.  Again in the presence of warm productive waters (provided by the island) we saw the presence of the second cohort

Looking to the future, the waters between Gran Canaria and Cape Verde are much warmer than we are seeing in teh crossing between Cape Verde and Brazil.  This means that we will likely see a situation much like when Scarlet reached the Azores, and so a cleaning will most likely be needed by the time Silbo reaches Cape Verde.  Then as we cross the equatorial counter current, we should not see any problems.  As seen below, we can see that even though at the surface the equator is significantly warmer, by 200m the temperature plummets to a level which we believe will be safe for Silbo.

On a final note, Silbo’s new batteries will arrive soon and redeployment will likely follow soon after.

Force Wind Sea & Honor

Antonio Ramos & Nilsen Strandskov

Hey all,

Yesterday was quite an amazing day.  First off, I would just like to acknowledge that yesterday, May 22, was National Maritime Day where in the US we honor those who are dedicated to promoting commerce and protecting our freedom.

Secondly, the company SpaceX launched its first commercial space craft, carrying cargo to the international space station, taking a huge step towards regular space travel post NASA’s Shuttle Program.

In other news, THE BEAR IS IN THE IGLOO!!!!  Yesterday morning at about 11am Canary time, Silbo was picked out of the water thus completing the mission he set forth on nearly 11 months ago.  Although there were some complications near the Azores which led to a hiatus as we waited upon new batteries, Silbo spent 238 days at sea covering 5555km as he bravely made the journey from the arctic waters of Iceland to the subtropical waters of the Canaries.

Some small fish swimming around Silbo in celebration

The morning started when we all (Antonio (ULPGC), Lauren(TWR), Alvaro(PLOCAN, and myself (Rutgers) ) met at the marina at 7:30.

We then met with the crew, Jose Blanco and Juan Carlos Gacia, and talked with the captain, Patricio Morenes and he described the strategy of how they wanted to pull Silbo on board when we got on site.  After we went and grabbed some coffee, we left port aboard the “patrullera SALVAMAR -NUNKI” by a little past 9am.

On our way out the seas were a little rough, with waves of 2.5 m (~8.5 feet) but with little wind.  The boat we were on was very fast, capable of traveling over 35 knots, however we stayed around that speed except when the Captain would cut the engine when we hit waves that were too big.

After a little over an hour of sailing out, it was time to set up the recovery station.

After the freewave and computer were set up, the waiting commenced as Silbo was set to surface somewhere near 11am.  So we waited…

Until finally, the computer chirped indicating Silbo was finally calling in!  We got an updated gps point from Chris back on shore in the US (thanks again for being up with us so early!) and we adjusted our position a little until Juan made the first sighting!

After sighting, the captain slowly approached the little droid, bringing it to the starboard side.  The strategy: lasso Silbo to drag him to the stern where there was a platform where we could easily pull him aboard.  On the first attempt, we didn’t even have a chance to throw the rope as Silbo zipped by the ship just narrowly missing the hull.

On the second try however, we roped him!

Juan and Jose moved Silbo around back making sure he kept a safe distance from the ship as they prepared to pull him on board.

And then, shortly after 11am on May 22, 2012, THE BEAR was officially IN THE IGLOO!!!

El oso está en el iglú!

So finally, after crossing through subarctic waters, the Gulf Stream, Azores Front, Mediterranean subsurface eddies, investigated the effects of two powerfull storms (Irene and Katia) over the North Atlantic, and finally touched the Antarctic Intermediate Waters, Silbo is safe on shore.  Truly Silbo has shown the capabilities of the glider for future ocean exploration.

Lastly, today Silbo received a warm welcoming as a press conference was held at the University of Las Palmas, Gran Canaria.

http://eldia.es

The Next: We had a small amount of biofouling, the dreaded Gooseneck Barnacles again!  What I plan to do is to measure the length of the barnacles and Antonio will use his algorithm to predict when and where they latched on.

This will give us valuable information of what conditions we will need to keep an eye on for future missions as we then cross track the estimated date with the data collected from the CTD and any archived ocean model data we have.  However, Silbo’s siesta will not last very long.

Next on our agenda, is to take Silbo from Gran Canaria, and pass by Cape Verde on our way to Brazil and beyond!  The new battery packs will arrive in Gran Canaria shortly, so once they are through customs, Chris DeCollibus from TWR will make his way out to re-battery and redeploy!

But as for now,

Force Wind Sea and Honor

Nilsen, Antonio & Lauren

P.S.
Articles Celebrating Silbo’s Success (en Espanol):

• http://www.canarias7.es/articulo.cfm?id=261993
• http://eldia.es/2012-05-23/SOCIEDAD/15-robot-submarino-recoge-datos-marinos-ineditos-Islandia-Canarias.htm
• http://www.laprovincia.es/sociedad/2012/05/23/cientificos-ulpgc-recuperan-glider-viaja-alrededor-mundo/459171.html
• http://www.laprovincia.es/sociedad/2012/05/24/silbo-viaja-rumbo-brasil/459421.html
• http://www.ulpgc.es/index.php?pagina=noticia&ver=210512silbo
• http://www.diariodeavisos.com/2012/05/23/actualidad/un-robot-submarino-recoge-datos-ineditos/
• http://carlosbas.wordpress.com/2011/09/15/silbo-se-acerca-a-canarias-navegando-desde-islandia-sorteando-las-tormentas-katia-e-irene/
• http://canarias24horas.com/ciencia-y-tecnologia/el-planeador-submarino-silbo-hara-escala-en-gran-canaria-tras-recorrer-casi-3000-millas-desde-islandia.html
• Silbo Media Press (pdf)

Hey All!

So we are now just about 8 hrs away from leaving port on our way to recover Silbo!

At 7:30am (canary time, 2:30am Eastern Time) we will be meeting at the port as we make final preparations to head out and recovery after Silbo has been at sea for 238 days while covering 5555km!  Silbo has been through probably more than any other glider, pushing the frontier as he sailed from the Arctic waters off of Iceland, fought his way against the gulf stream, took the Azores front head on, was tossed by over 50 storms, touched the edge of the Mediterranean outflow passed by sea mounts, dodged ships, surfed the Canary Current, and tasted the tongue of the Antarctic Intermediate Waters- and that is only the stuff we know of from on shore!

Today, our team met to make some decisions about where to recover.  Over the past day and a half now, Silbo has been drifting to the east, so it was proposed by Antonio to move  the wp west in order to correct for this and keep us out of the shipping lanes.

However, there is always more one side to the story, as we then looked at the activity of the currents from multiple models:

Comparing the currents derived by silbo, hycom and ncom, we had 3 different stories of what was going on. With this in the back of our minds, we also had to take bathymetry into account as we didnt want silbo running aground.  Luckily, we have at least 20 km between Silbo’s location and any need to panic there.

So finally, as we cross our fingers and wait for the morning to come, we look into what the rest of the models are telling us about how the currents and remnants of eddies, broken up by the location of the islands, are dictating the movement of the waters around silbo.

Hycom Salinity

Hycom SSH

Another useful tool we have access to thanks to the ftp site created by our friends at ULPGC is making a gif allowing us to see the progression of marine conditions over a number of days:

Ncom/Nlom Currents and Sea Surface Height May 16-20

This can give us a ball park estimate of what to expect in the times to come.

Antonio also provided us with fascinating imagery of the regions showing the temperature, sea surface height and salinity over the last 5 days of the mission.

Sea Surface Temperature May 17-21

Sea Surface Height May 17-21

Sea Surface Salinity May 17-21

Salinity at 900m depth May 17-21

What is really outstanding is the purple and blue colors at the bottom of the last image showing the antarctic intermediate waters reaching up and interacting with the mediterranean outflow creating the spectacular design.

Tomorrow morning is going to be a long day, current forecast is showing seas of about 2.5m so it is going to be a bumpy ride on our little rescue boat. So I need everyone to pray for a flawless recovery mission and I will update everyone tomorrow with the news!

ps- Ru25, another deep glider owned by Rutgers, has been deployed off of the Azores and is ready to make its way up to Iceland!

Force Wind Sea & Honor!

Nilsen, Antonio & Lauren

Hey All!

So I (Nilsen) am officially in the Canary Islands where over the next month I will be at PLOCAN working on Silbo’s recovery, rebattery,  redeployment and piloting.  I will also be assisting our friend Alvaro who has been helping Rutgers since the RU 27 trans atlantic mission, working on the adcp data from plocan’s slocum glider and helping with the prep for another deployment.

Yesterday, I attended the Liquid Robotics/PLOCAN deployment of a wave glider off of the southern coast of the island.

The wave glider (pictured above) is pretty different than the slocums I am used to.  This type of glider is tethered to a float that stays on the surface and is laden with solar panels and various sensors for surface waters and meteorology.  Instead of using a pump as its drive of propulsion, the wave glider has a total of 12 fins that pivot with the motion of the sub surface waves thus driving it forward.  It then drags the surface float along at the surface.

I have also begun to settle in at my desk in the cool room on the other side of the Atlantic which I have only seen in the back ground of numerous skype sessions with plocan.

As for silbo, he is now less than 35 km from where we will recover on the morning of Tuesday, May 22. 

At 8am Tuesday, Antonio(ULPGC), Lauren(TWR), Alvaro(PLOCAN) and myself will leave from Muelle deportivo as we make our way out to recover the brave little Silbo on this ship:

We will meet silbo about 45 km to the North West of Las Palmas (designated by the last way point).

The weather also doesnt seem to bad for recovery even though the winds and waves from the north gradually increase.  However with the ship we have it should not be a problem.  (Below we can see the correlation between the increases winds and wave activity)

Wave Forecast provided by Antonio

Wind Forecast from Antonio

Finally we have the all mighty ship traffic.  Over the past few days we have been playing the old “Frogger game” of crossing the shipping highways to and from the island.

And so taking all of this into account, we have chosen the last way point of the mission and wish silbo luck on the final days of the mission.  It is truly incredible what this little droid has been through over the past 11 months.  From being deployed in the arctic waters of Iceland, to breaking the plane of the gulf stream, riding the azores front and canary current and finally, reaching the antarctic intermediate water.  He has set forth quite a legacy to follow that of RU 27 and which will most definitely be upheld by his upcoming missions accompanied with the growing challenger fleet.

As always, Force Wind Sea & Honor

Nilsen & Antonio