Category: silbo (Page 20 of 22)

Hey All!

Well after a week of amazing flying, Challenger 1 has now made it south past the 60° N Latitudinal mark and is now in the 50’s!  This past week, the glider has maneuvered it’s way through the solar system of eddies Antonio has described previously of the warm core eddy surrounded by a number of cold core ones spinning in the opposite direction.  By using these gyres, we were able to fly south at a pretty awesome speed (reaching 1.35km/hr at some pooints) going nearly 30 km in one day, even though the overall geostrophic flow of the surface currents were to the North.

Total Currents Field from Antonio

In the above image, Antonio plotted up for us the total current field along with sea surface height to best show the position and movement of the eddies in our area.  You can see how to the North West of us there is the warm core eddy that we just used to send us to the south into the cold eddy that we now plan to utilize to swing us around along the path of the arrow.

Even in the presence of all of the storms we have seen, we are still making progress.  It is looking like for the weekend at least we are going to have good weather but as the beginning of next week rolls around we may see a shift in wind and another storm headed our way. In the bottom left side of the pic below you can see the next storm system that will be making its way towards Challenger 1…

Satellite Map of the storms from Antonio

Also Looking at the forecast for the jet stream, it confirms that we have what looks like favorable weather for the next 2 days or so but that starting early next week we may have some violent shifts in the wind patterns above us.  Below is a picture of the current conditions for the jet stream, but if you click on it, it links to a gif that will show the forecasted progression over the next week.

It should be interesting what we see over the next couple days, as this will be the first weekend we fly without current correction on.  Our plan is to follow the path of the cold core eddy we are currently flying near and following it around to the south, allowing Challenger 1 to drift with it.  This will use less energy as we will not be trying to fight the currents as the glider tries to fly directly to it’s most recent way point (opposed to flying with current correction on and fighting the currents to fly a direct path).

After now being at sea for 3 weeks Challenger 1 has flown over 500km and collected some really cool looking data.  Below we have nearly continuous cross sections from the deployment through the most recent surfacing of Density, Salinity, Temperature, and Sound Velocity respectfully.

Density

Salinity

Temperature

Speed of sound through water column

Finally, we have an update on what has been going on over the past couple days with the deployment of RU 28 that we helped with on Wednesday.

It’s Wednesday, July 13, a beautiful afternoon in Jersey City, New Jersey, today is the day where we deploy our first shallow (30m) glider. As we (Nilsen, Alberto, Ruben, Lindsay, Garz, and myself) are unloading the glider van, taking out RU28, a CTD, and other various instruments; we are greeted by our captain and two EPA members. The view as we left the dock was quite humorous, to our right was a huge landfill with a squadron of cranes, swiveling about moving who-knows-what; to our left was Manhatten with the Chrysler Building and the Statue of Liberty in all their glory. The seas were excellent that day, only the occasional semi-massive wave would knock you slightly off balance. As we sailed to our destination, we passed some bluefish, packs of seagulls, shipping boats, sailboats, and a lonely beachball, forever deprived of the playfulness of a child. When we reached our destination, Sandy Hook was visible on the horizon and deployment mode was switched on, Lindsay and Mike delved into the pre-launching routine while everyone else got RU28 ready to depart from the back of the boat.

Oliver Standing by on the back deck with RU28 as we sailed out to the deployment site

All systems were go, Dave from IMCS gave us the green light and RU28 was cast off. After a preliminary dive and surfacing, RU28’s job had begun and we sailed back to base, escorted by seagulls and terns.

Garz and Nilsen deploying RU28 off the NJ Coast by Sandy Hook

So now we have two gliders out in the water, Challenger 1 and RU28, located off the coast of Iceland and Sandy Hook, respectively.

Nilsen & Oliver

Hey all,

Well Challenger 1 has really had a run for its money since deployed almost 3 weeks ago.  We are now being affected by our 5th storm!

Even after being battered and bruised over the past few weeks, we are still making good progress!  In the midst of the storm, the currents are for the time being moving North East as Challenger 1 cuts to the south west thus avoiding the direct head current.  By doing so we have gone 9 km two surfacings ago and just over 11 on the most recent! (much better progress than we have been seeing recently)

In the above picture, we can also see the liquid meccano that our friend Antonio has been mentioning over the weeks.  There are a number of eddies in our area that have caused curves to appear in the overall northern current.  In the upcoming weeks we will take advantage of these as we continue our progress to the south.

I’d like to take this time to introduce our new student allies from the Canary Islands, Rubén Marrero and Juan Alberto González from La Universidad de Las Palmas de Gran Canaria, who will be staying with us for the next few weeks. Rubén is specializing in electronic engineering and Juan Alberto is specializing in oceanography.

Alberto (left) & Ruben (right)

Finally, I would just like to mention another glider related mission our group is working on.  Later today we will be out on the water deploying RU28 which is a shallow glider (depth range of about 30m) off of Sandy Hook and it will work its way down to Cape May NJ after a 3 week cruise.

Nilsen & Oliver

Hey Guys!

Well Challenger 1 has been acting more like a rocket lately than a glider.  Today alone we have gone just over 28 km, hitting speeds up to 1.4km/hr!  However on the last segment we did slow down a bit as we began fighting the currents slightly as they shifted from south to west.  A possible way point change may be helpful in better harnessing these currents and use them to our advantage.

It will be important to use these currents as best we can over the next few days, as they will only be around for a short while longer.  Looking at the jet stream forecast for the next few days, it looks like a storm system will be rolling in by Sunday and wrecking havoc until at least next wednesday (thats as far as the forecast goes and it doesn’t look good).

metcheck.com's forecast for Sunday when the winds begin fighting us

Sunday, the winds are forecasted to shift against us and in the days following we will most likely be hit with the red-orange system as it curls to the North.  So what we want to do is set a few way points over the next couple days to try and maneuver through these currents as they shift with the power of the jet stream.

Antonio also provided us with crucial Sea Surface Height data showing we have a number of cold core eddies (ponds) surrounding a warm core eddy (hill) that are in our path. We think the best course of action is to follow these eddies around and try and shoot ourselves as far south as we can by using the alternating currents caused by the cold and warm eddies (cold eddies spin counter clockwise while warm spin clockwise).

Antonio's SSH image for July, 6

Nilsen & Oliver

Greetings all,

First off, hope everyone had a great Fourth of July! Now back to the Challenger Mission.

Although fighting against the storm has slowed us down, we’re still persevering. Luckily the aftermath of last week’s storm has left us currents flowing to the Southwest as opposed to last week’s currents of directly West. But there is an eddy to our West so we must be mindful of that as we approach the favorable currents. The image to the left depicts our total progress so far with a temperature overlay and the image on the right shows the eddy to our west and the Southwestern currents  a little ways away from us with a sea surface height overview.

The following image is from stormpulse.com and shows that Silbo has braved the storm and is more or less “out of the frying pan,” since that large cloudy band is now to our East.

This massive storm is what has caused the currents to be so unpredictable over the past week, where we were seeing the currents make full 180° shifts every few hours, rendering our 24 hr models unreliable.  Over the weekend when we were hit with a majority of the storm, we saw the strongest effects of the shifting currents as our distance covered per surfacing had huge ranges, going from about 6 km to almost 12!  But now that the storm has passed and the skies are clear (for now) we are more consistent.

Unfortunately, the storm left us back with currents heading West, out into the mid Atlantic.  Although better than a strait on head current, we are still doing quite a bit of fighting as Challenger 1 tries to correct the amount the glider drifts while trying to get to its way point.  To try and help us decrease the amount to which we are fighting the currents and to increase our speed, we are shutting current correction off.  Hopefully this will allow us to go a little more with the current, thus increasing our speed as we fly less directly into the currents pushing us out to the west.

Oliver & Nilsen

Hey all,

First off, we would just like kick off the 4th of July weekend by congratulating Challenger 1 and the rest of its team on making it through the first week and 200km of this mission, roughly 5% complete!

Now looking to the North Atlantic and our glider, it looks like the storm we mentioned yesterday is really causing some havoc.  Where we left off yesterday, we had nice strong currents pushing us along running in the south – south west direction (image with the overlay).  However, today it’s almost the complete opposite as the currents have shifted and are moving to the North West (image without the overlay).

It appears that the storm is changing conditions around us faster than our models our updating, so path planning looks like it just got a little more difficult.  In the up coming days, we will begin checking out satellite data for chlorophyll a (the main pigment in the ocean’s primary producers) along with other data sets in hopes that we can get higher resolution predictions of where the currents are moving.

Another resource we have started looking to try and get an idea of the storms progress, is looking at the Jet Stream.  Towards the  end of 27’s mission, we found a correlation between the presence of the Jet Stream, wave heights, and direction and intensity of the currents.  Bringing these resources back into play, it looks like we are just on the outer edges of the storm and that it may slam right into us.

Jet Stream on July 1 from metcheck.com

Waves as of 6:00 GMT on July 1 from oceanweather.com

Dave and Shannon also have provided us with a new sea surface height model that we have began using.  Now I know you may think ‘hey I thought they already had a model for ssh…’ but it is actually very important to have many perspectives on this sort of thing (this will be our 3rd SSH model).  There actually are some eddies that hadn’t seen previously in our other models, and that is what is to be expected.  By having all of these resources pooled together, we can make more accurate predictions as to what the actual conditions are and more effectively maneuver the glider.  Another important element to this SSH model is the large red feature to the south west.  This is a body of water that is extremely high (nearly 148 cm in some places) and we will be keeping a close eye on how it moves as to try and plan how to take on that sort of challenge if it arises in the future.

And as the old saying goes, speaking “rabbit rabbit” upon waking on the first of the month will grant good luck.  So to Challenger 1 we wish you luck over the next month and to everyone else I hope you enjoy your holiday weekend as we celebrate our great country’s Independence!

-Nilsen & Oliver

Hey all,

Well we are still chugging along, and making good time at that!  Yesterday afternoon, Challenger 1 was given a new waypoint back to the south east, and now we are heading almost directly south at an astonishing 1.35 km/hr (which is excellent for a glider) and have gone about 24.5 km since yesterdays afternoon surfacing.

There has been recent discussion about the currents that the glider is recording.  It seems that no matter which way we are moving, we are recording currents that are going about 90 degrees to the right, which haven’t always correlated with what the Hycom model is telling us, and is also pretty suspicious in itself.  Within the next couple of days, we will begin flying with a program called current correction set on to try and correct for what the glider thinks the currents are doing and see if that makes any changes to our heading.

Next, we continued looking to the depths to make sure we stay a safe distance from the bottom.  Today I overlayed the bathymetry map from geomapapp onto google earth so we could see it along with the hycom currents and current glider position.  The cross section I took follows the path the glider would be drifting if we were continuing to follow the current and even in this scenario, the shallowest water is still about 1300m.  So we should be fine for the time being if we continue to dive to 1000m depths.

Shannon Harrison and Dave Kaminsky who have both been involved with the COOL room for many years also contributed to the path planning this morning; thus increasing our global collaboration to include our fellow Rutgers students currently interning all the way over in Perth, Australia at the University of Western Australia where they are helping with research in the Oceans Institute in conjunction with the Australian National Facility for Ocean Gliders and the Integrated Marine Observing System.  They pointed out that there are two general directions of the currents which they depicted with the two blue arrows, the red line dividing the two.  Both having experience in piloting gliders, they advised us to continue looking at the movement of the eddies to see how they progress now so we may plan for when we reach the areas with the most movement.

Another thing we must worry about, is the intensity and direction of the eddies changing largely unpredictably due to storms.  Due to the kinetic energy of the wind, the eddies may grow in both size and intensity in the presence of a storms.  And just our luck, Antonio pointed out today that there is a massive storm system headed our way!  To minimize the storms interference, we may take a look at our operational depth and make sure we are not rising up into waters that may be disruptive until we need to surface.  We will also need to keep an eye on our current models as the storm may cause eddies to change before the model has a chance to update.  This may lead to some discrepancies along the way.

Lastly I (Nilsen) would just like to apologize to our dear friends Antonio, The University of Las Palmas at Gran Canaria, and PLOCAN for any confusion I may have caused.  I accidentally gave Antonio’s work credit to PLOCAN in two of my previous posts, when his official affiliation is actually with U. Las Palmas GC.  However, U. Las Palmas GC does collaborate quite regularly with PLOCAN.  So again guys my greatest apologies!

-Nilsen & Oliver

Hey all,

So today we we continued our global collaboration to choose our path for Challenger 1.  In order to conserve battery power, we have now turned off our altimeter.  This will causes us to use less battery power which is crucial while we are still in the first days of the mission flying in frigid Arctic water.  However, we are now flying solely off of bathymetry maps.  Luckily, between U. Las Palmas Gran Canaria and Rutgers, we have found two different models showing the depth of the sea floor in the area we are flying that correlate very well and so have boosted our confidence allowing us to do away with the altimeter at least for now.

Bathymetry Map provided by Antonio

In the above images, the top being from Antonio and University of Las Palmas GC and the bottom two being from Rutgers, we can see that we should be safe of running aground if we stay in the channel between the Mid-Atlantic Ridge and the rise off of Europe.  Zooming in, it looks like we will have to avoid the line going diagonal south in the image below (starting from about 24) if we want to continue safely flying to 1000m without our altimeter on.

So after studying the bottom, now we must take into account where the water is going and how the glider is flying.  After moving the waypoint yesterday to try and get us moving further south, our speed dropped from between 1.2-1.35 km/hr to .87km/hr.  We seem to have hit a small eddy whose currents had started sweeping us west.

Antonio provided another similar model that showed that we are in the midst of a few cold eddies that if we maneuver around correctly, we will be able to shoot ourselves further south and find a few more currents that will aid us along the way.

Sea Surface Height and Currents Provided by Antonio

Another thing which may prove piloting this glider to be a little bit tricky, is we have some reason to believe that Challenger 1’s compass may be slightly off and could possibly be over estimating the power of the currents resulting in a heading error.  On Monday, back before the waypoint was changed, we calculated that our heading was off by about 40 degrees, which from previous experience could be explained by the compass and an over estimation of currents.  Today, we recalculated after finding the loss of speed, and found that today we were off by a little under 50 degrees which again could be a result of the currents that we were now fighting.  Taking this into account along with the eddies we are now trying to navigate, we will have to move our waypoint further east to effectively get Challenger 1 on its way south.  During the next surfacing we will give the new point to the south east and see how we fly.

Finally, yesterday evening back home in the COOL room, visitors from The Ocean Observatories Initiative or OOI, were given a tour of our facilities by Scott.  Our visitors are some of the leading names in modern day Oceanography, and through OOI are revolutionizing the way we study the global ocean.

-Nilsen

Hey all,

Well quite a bit has happened since we last checked in, so lets jump back to Friday afternoon.

After giving us quite a scare less than a day into its mission where Challenger 1 missed its call home due to technical failures on our end, the glider almost mockingly called in once an hour for over 10 strait hours Friday afternoon through Saturday morning.  But it wasn’t just trying to prove a point to its parents like an obnoxious teenager, it was running a series of tests.  The results allowed Challenger 1 to auto tune it’s own ballast settings, which will allow for it to most effectively navigate the depths with its saw tooth flight pattern.  This nifty trick may prove to be very beneficial as we move south to waters with different densities that may require a re ballasting.

The next great update is that on Sunday, Challenger 1 crossed the shelf break and is now flying in deep water.  After the first dive to 1000m, we were already seeing improvements in the flight pattern.  We are flying straighter, meaning that by flying deeper we are being effected less by the surface currents which are moving in a North- West direction (the exact opposite of where we want).  Flying to 1000m depths also really helps us out with battery power.  Going that deep, we only make 2 oscillations over about an 8 hr period which means we are going further along our track while only having to make the internal movements necessary to make climbs or dives twice between surfacings (compared to 6 times when we were in shallower waters).

Today we began our global collaboration to choose waypoints to pilot the glider now that testing is done and we are truly on our way.  Antonio and our friends at University Las Palmas Gran Canaria gave us some great advise on either taking a route that takes us directly to the Canaries, or further out west towards the Azores.  The path heading directly to the Canaries will offer us a more direct route through waters that are very well known and modeled.  The other option will put us in less sampled waters where we will very likely find discrepancies in our models, similar to what we saw during the 27 mission.  The westerly route also leaves us the option of swinging by our old service station, The Azores, if we run into any real trouble along our journey.  There is a draw back however of that this will add about 15% to our journey and may lead to problems if we don’t have sufficient battery.

Our decision for the time being is to just focus on getting south out of the colder waters for now.  The sooner we do this the better, as the cold waters tend to cause our batteries to be drained much faster than if we were in warmer waters.  The good news is that we are moving at break neck speeds!  Typically the gliders we have worked with in the past have gone an average around 1km/hr.  Challenger 1 however has been recording speeds up to 1.35km/hr!  Hopefully if we continue to make good time, we will get out to safer waters and we can continue on our historic journey.

Finally we have a quick update on the conditions Challenger 1 is facing:

The glider is flying smoothly and will now be surfacing every six to eight hours. In this picture you can see her slow but inevitable descent from colder Northern waters into the ever-warming waters of her Southern location.

Here’s a picture of the shipping routes in our general path, the coast is clear for now. As expected, there is a lot of activity along the East of our path but we’ll have Silbo navigate efficiently through whatever comes our way.

-Nilsen & Oliver