Tag: Nilsen Strandskov (Page 1 of 11)

Continuing the Legacy

Hey All!


As Silbo continues his mission to Brazil, I would like to take a step back and talk about the future for not only Silbo, but the expanding Challenger Fleet.

Since the initial deployment on June 25, 2011, Silbo has flown over 8,241 km over the course of 379 days making progress from Iceland south past the Cape Verde Islands.  Although we have been struggling with the strong head current that we have been in the midst of for nearly a month and a half now, Silbo is just over 2,000km from the Brazilian coast line and 4,500km from our expected end point of Rio de Janeiro; a distance we hope to cover by June 2013.

Once in Rio, Silbo will get a break as we get a team down there to clean and rebattery the little droid.  Once the maintenance is done, Silbo will get back in the water with our eyes set on the Antarctic.  We hope to take Silbo across the Drake Passage and make landfall at Palmer Station in Antarctica.  If you click on the link below, you can see a video created in Google Earth Pro reviewing Silbo’s progress and highlighting his future goals.

Silbo’s Mission: Connecting Poles from North to South

Last week on Tuesday Dec 4 2012, the 3 year anniversary of the conclusion of Scarlet’s legendary crossing of the Atlantic connecting NJ to Spain, Zdenka Willis, Director of the US Integrated Ocean Observing System payed Scott Glenn, Oscar Schofield and Josh Kohut’s Ocean Observatory course a visit.  After giving an inspiring presentation to the class on the progress IOOS has made over the past decade, Zdenka concluded her talk with the Christening of RU 29, CHALLENGER.  She explained that the christening of a vessel is a tradition that dates back to the Third Millennium BC in stories from ancient Babylon.

“Even though the actual ceremony has changed over time, the tradition, meaning, and spiritual overtones remain constant. The vast size, power, and unpredictability of the sea must certainly have awed the first sailors to venture far from shore. Instinctively, they would seek divine protection for themselves and their craft from the capricious nature of wind and water. “

These traditions follow the same process as the saying we have adopted over the course of Silbo’s mission: FORCE WIND SEA & HONOR

Click here for all of the pictures from the ceremony.

We received 29 back in the spring of this year, being Rutgers first Stretch G2 glider meant for the long duration flights that The Challenger Mission will comprise of.  This summer we had 29 fly for a month off of the NJ Shelf so we could run a number of tests and get a feel for how the glider would fly.  As we have previously mentioned, the test mission ran smoothly until the weekend where we planned on crossing the shelf to head back into shore, where there was a communication problem that led to a massive drop in battery power.

Now after a few months in the lab, 29 is entering the final preparations for its first leg of the Challenger Mission.  After getting a coating of anti biology paint, 29 will be shipped down to Cape Town South Africa where in early January it will be deployed.

The plan at this point is to take 29 and make a mirror image to what Silbo has done, crisscrossing his path flying from South Africa, past the Ascension Islands to Fortaleza Brazil, North towards the Caribbean and Gulf of Mexico, further North past NJ to Halifax Nova Scotia and then cross towards Ireland and finally end in Svalbard; effectively connecting the two poles in the same fashion as Silbo.  If you click the following link, there is a video highlighting the path we hope to take with 29.

Challenger’s Mission: Connecting Poles from South to North

In preparation for the deployment, we have been looking into the bathymetry of the region.  Our friends in the glider program out of South Africa have mentioned a valley that they have flown gliders in previously that we plan to take as we fly out out to International waters.  Once there, we will then head north along the route highlighted above.

Another piloting aspect we have given some thought to has been the presence of Great White Sharks.  The waters off of South Africa are known for the presence the Great Whites have their, and we have had some bad experiences that involved glider interactions with these sharks.  Just this past summer, we had a shark try and swallow a glider off of California resulting in the wings being snapped off.

We predict that these missions will take us through until late 2014

These Missions that 29 and Silbo have been working on, as we have mentioned previously, are part of the Challenger Mission.  This goal is to take a fleet of 16 gliders and recreate the path of the HMS Challenger circumnavigating the globe in the name of science.  As Silbo and 29 run these test missions, we will continue to build the fleet which we plan to have in the water from 2014- 2016. The map below is a rough path we hope to take over the course of the two years.

The following link is a Google Earth Pro movie of the paths we plan to take.


Finally, we have another branch of our expanding fleet that is being volunteered by our partners at Teledyne Webb.  They are in the process of designing a new Thermal Glider that they will fly jointly with Rutgers to kick off the legs of the Challenger Mission in the Pacific.  We plan on deploying two of these Thermal Gliders over the course of the next year.  This design builds off of the previous collaboration TWR and Rutgers has had piloting Thermals in the Atlantic in 2009 and 2010 with Cook and Drake.

As for now, the first of the two Thermal Gliders is planned to be deployed out of San Diego in late Winter/Early Spring and will head south west.

Force Wind Sea & Honor

0 – 3

Hey All!

Over the past few weeks Silbo has continued his way past the Cape Verde archipelago and on into the open ocean.  Progress has been slow however as the currents have been strong to the North, North-West and North-East; the opposite of what we see as ideal.

After rounding the most western island of Cape Verde and fighting a pretty strong head current as we tried to make progress south, we moved the way point out west to try and increase the ground covered between surfacings.   By doing so, we are trying to take a more northern route across the Atlantic so that at the later end of the mission, we are in better shape for an emergency recovery off of Brazil rather than being stuck in the middle of the ocean.

Another reason behind this decision, is that at the moment, we have very little options for routes to the south.  For weeks now, the current in our vicinity has largely been flowing to the North.  So as we slowly make progress, we are hoping to find an outlet that may help us in the direction we want to go.

Unfortunately, our road maps are not always as reliable as we would like.  Of the three different ocean models that we have been using throughout the mission, all three are showing a current that disagrees with what Silbo is showing us.  While Silbo is showing the currents moving to the north in a pretty strong jet, the RTOFS, MyOcean and NCOM models all show a current flowing to the south:

Real Time Ocean Forecast System Sea Surface Height & Currents

NCOM Currents & NLOM Sea Surface Height

MyOcean Sea Surface Height & Averaged Currents 0-1000 m

MyOcean Sea Surface Height & Averaged Currents 0-1000 m

As the current continues to look unfavorable, Silbo and our team will persist in our attempts to fight back and try and make progress towards Brazil.  Hopefully a new path will reveal itself soon and Silbo can coast a little after fighting for so long.

Force Wind Sea & Honor

Nilsen & Antonio

The Long Awaited Photos

Hey All,

sorry about the delay on my end, but here are the photos from Silbo’s inspection mission!

A special thanks to Alvaro Lorenzo and Laura Cardona from PLOCAN for taking part in this mission and getting Silbo ready to cross the Atlantic

Current Analysis

Hey all!

Over the past week, I have been looking at a way to check the accuracy of the tools we use to pilot our long duration gliders. So far, we have been using wind mapping sensors and wave height analysis from Marinemet, NCOM geostrophic currents, myocean currents at various depths through the water column,  and the ROTFS model.  This week I was able to run a preliminary analysis on the myocean and ncom data sets.

As both data sets are available in netcdf format, I was able to dissect them and easily pull out the data for the area around the glider.  While the NCOM data is the geostrophic average, there is only one data point to directly analyze, but with myocean, we are able to take a number of points throughout the water column from surface to the depths Silbo dives to (in this case 1000m) to average.  The myocean data is pretty interesting to compare, as in order to do so, I take a number of points and take the average, similar to how we arrive at the currents that Silbo records.

At the beginning of the week, I calculated the the % error of the values for the models using the numbers recorded by Silbo as the accepted value, and both were roughly within 15% from the magnitude of Silbo, and 20% when direction was compared.

Towards the end of the week I began making these plots that I will keep up when I have the chance, visualizing the magnitude and direction or the currents, withe the blue arrow being of the myocean data set, green being NCOM and red being Silbo.


Force Wind Sea & Honor

A Triumphant Examination

Hey All!

Well the inspection mission was a success!  Saturday morning, Alvaro and our team from PLOCAN arrived on site to meet Silbo aboard the Islandia after leaving port late the night before.

News from the boat is that there was some barnacle growth on Silbo’s nose cone which we will have photo and possibly video footage of within the next couple days, along with a more in depth play by play of the goings on of the inspection.  However, Alvaro was able to scrape the hitchhikers off and wish our little droid luck as he prepares to cross the Atlantic.

Before he departs on this epic journey, Silbo is doing a lap around Geomar’s mooring that is in our vicinity.  Tomorrow, Silbo will be given instruction to enter into low power mode, proceed to dive to 1000m, head to the north west to round the corner of the western island of the Cape Verde Archipelago and the two seamounts, and leave sight of land as he heads out into the North Atlantic.

Force Wind Sea & Honor


Nilsen & Antonio

Nearing the Cape and Preparing for Inspection

Hey All,


So it has been a hectic month, but Silbo and our team are making final preparations for an inspection that will take in the early hours of the morning.

First let us back track a bit and catch up on what has happened in recent weeks.  Since Antonio and I did the barnacle analysis back in June after recovery, we started making projections for potential growth on the next journey.

From our findings, we saw that due to the temperature variations in the water column of the North Atlantic, it would be more likely that we saw substantial barnacle growth between the Canaries and Cape Verde than Cape Verde to Brazil due to the temperatures at depth (seen in the temperature map above).  Another point supporting our hypothesis was that we were flying Silbo through some of the most productive waters in the world, thus why the islands have been called Cape Verde.  This year has also been a very productive year as there have been a number of strong wind events over the Sahara that have deposited iron rich dust into the waters off the African coast which have sparked some large blooms.  So as we flew Silbo through these productive waters, we began to worry that we may start picking up some hitch hikers.

To try and monitor if we were picking anything up, I began looking at Silbo’s velocity with the help of Dave Aragon.  We initially looked at the raw vertical velocity Silbo reported at each surfacing.

As the weeks went on, we saw some slight indications that we were going slower, but we couldn’t be completely sure of what was going on.  We then started filtering data, taking out times that we were at the surface, and then correcting the data for changes in pitch and ballast to try and get a better estimate on what the velocities were.

We also added a 10 day average to see any trends in the data, and we saw that there was a definite slowing occurring over the course of the last three weeks.


We had previously discussed a collaborative 48 hour station keep in the vicinity of the Geomar mooring site just north of the islands of Cape Verde and we proposed the plan for an inspection.  This would be our last opportunity for contact before Silbo would leave the coast and set sail to cross the Atlantic with Rio De Janeiro as our finish line.

After coordinating with our team,  PLOCAN was able to secure a boat and a crew of scientists and technicians to go out on a boat, while our friends Ben and Lauren at Webb provided ground support for an inspection.   The tricky part it seems will be communication as the boat does not have internet and our team is without a satellite phone.  So what we plan to do, is to use Silbo’s iridium and freewave connection as a sort of instant messaging service, with Ben and Lauren leaving messages for Alvaro via iridium and Alvaro responding through the freewave.

Alvaro and our friends have left harbor a few hours ago now, and plan on being on site by 8am gmt, so as they near the area, Ben and Lauren back in the US will be ready to catch Silbo and stop his mission so that the ship can find him.  While Silbo waits for the boat, he will drift with the currents it looks to the west (red is surface whiel orange and blue are 250m and 500m respectively).

News of the inspection will be relayed back throughout the morning, so over the next couple of days we will make sure to update everyone and release the pictures!


Good luck to our team!

Force Wind Sea & Honor

Nilsen & Antonio

A New Spin on our data sets

Hey all!

As we head into the Labor Day weekend, Silbo is continue to fly along as he continues to keep up a good pace of over .3m/s

With the new way point we set last week, we really started to cruise to the southwest setting our speed record for the mission thus far and keeping an average speed up of roughly .3cm/s.

Looking at the Satellite imagery (curtsy of Antonio &  http://www.afrimet.org/marinemet/ ) although there is quite a bit of cloud coverage blocking our view, we can see there this is quite a bit of productivity in the waters to the south east of Silbo.  Relative to the image below, Silbo currently is flying through the upper left corner of the map, where the imagery cut off.

As for our data, this week we will have a new way of looking at the data we have been using all along.  I have been working on getting the code that Mike Smith uses to visualize the CODAR data we have along the Mid Atlantic Bight and applying it to the data sets Antonio has been supplying us with since Silbo’s deployment off of Iceland over 16 months ago to create kmz’s that will allow us to see satellite and ocean model data accurately visualized in google earth along with Silbo’s latest position, allowing us to see what the conditions of the water are like not only at the surface, but throughout the entire water column.  Although there are still a few more things to work out, below I have an image the currents at the surface, 100m, 300m, 500m and 1000m in the area around Silbo.  This along with temperature, salinity and wave height data will allow us to make more accurate decisions for glider piloting, which will really prove its value as we continue to grow our global glider fleet.

Force Wind Sea & Honor


Nilsen & Antonio

1 Month at sea

Hey All!


well it is hard to believe, but Silbo has been back at sea for a month already as he voyages south towards Cape Verde.

Granted we have had a bit of a sluggish start as we have had unfavorable currents basically since deployment, I have made an estimate of where Silbo will be on the first of each month as he crosses the Atlantic basin.

If we can keep Silbo in more favorable currents (which will easier in the coming weeks) we will undoubtedly fly faster than this projection shows, but Silbo should make landfall in Rio sometime in late spring 2013.

As for our current flight, the currents are pretty mundane and so we are nearly flying at our own will, allowing us to fly a nearly straight line towards the way point.  In the coming days as we move further south, we plan on swinging the way point out west to catch some south westerly currents that will carry us out further from the west african shelf.


Force Wind Sea & Honor


Nilsen & Antonio


We have all of the time in the world… Literally!

Hey all


After our little bought with the strong north east currents, Silbo has gotten back on course towards the south west.  Looking onwards, Silbo has a long and winding road ahead, as he flies south past the Cape Verde Islands, across the Equator and on the Rio de Janeiro.

The distance between Silbo and our ideal recovery sight is roughly 7,400 km, with our only safety net being Cape Verde.  This leaves us with nearly 5,000 km of open ocean flight where if we run into any trouble, it will be tough to get ourselves back out.  But in the name of science and adventure, Silbo is backed with a team that are determined to safely navigate him through the Atlantic and assure his safe arrival.

One way in which we have prepared Silbo for this journey is we have crammed his hull to the brim with lithium batteries, which when coupled with the new low power mode setting released by TWR has given Silbo over a year of energy!


In the plot above, we can see that Silbo’s batteries are projected to last somewhere between 14 and 16 months from now giving us the potential to fly until January 2014.  How low power mode works is that instead of leaving the flight computer on 24/7, the computer is only turned on every 30 seconds during dives and climbs (after becoming situated during the process of inflection).  This conservation of energy has now given Silbo a very nice cushion, relieving us all of the stress of running out of power.


Force Wind Sea & Honor!


Nilsen & Antonio

Clearing up the Mystery

Hey All,

I just wanted to update everyone on what happened last week when we flew backwards.

Last week, Chris DeCollibus (TWR) looked into the surface dialogs from Silbo around those surfacings and found the answer.  It seems that Silbo miscalculated the currents that it was encountering which resulted in the flying backwards.  When the mission was reset after we gave Silbo a new way point, the calculations of the current showed a significant difference, and so when Silbo was flying towards the way point, he flew using his dead reckoning and the incorrect currents.  This lead Silbo to believe that he would surpass the way point and needed to turn in order to arrive in the correct location.  If he were to continue flying without turning, the logic of  the glider believed that it would fly well beyond the way point.  This mishap combined with the strength of these currents resulted in Silbo then flying 14km “backwards”.

Now we have new questions to answer: how can we speed Silbo up?

In the image above, I have taken the average velocity of Silbo for each segment he flies: red indicates the trip from Azores to Canaries and blue is the current mission.  So far on this mission, Silbo has been flying significantly slower than on the previous mission.  This potentially could be from the increased weight from the batteries over the previous configuration, but we need to discuss means of speeding up a bit.  On another note, in figure above, the red line from the previous mission shows how towards the end of the mission the velocity decreasing by nearly 1/3.  This correlates with the presence of the two barnacle cohorts described and analyzed here: http://www.i-cool.org/?p=11984

Force Wind Sea and Honor All!


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