Author: admin (Page 10 of 36)

In preparation for the recovery early tomorrow morning, Scott and Chip took a trip out to the ship that will be used for the operation.  It is a larger ship than can dock in the area, so it gets parked close by and a zodiac is used to load.

view from the zodiac ride out to the USP RV Alpha Delphini

Upon arriving at the boat, they took to the bridge to see where they would set up the equipment to communicate with the glider once on location.

View of the bridge aboard the Alpha Delphini

View of the A-frame

Once on location, the plan will be to get the glider on a cart into the zodiac and then use the A-frame to transfer the glider from the zodiac to the aft deck.  Once on board, the team will then return to the shore lab, and the glider will be sailed south to Santos where it will be handed over to be inspected by customs on monday.  If it clears customs,  29 will be transported back to the shore lab by truck monday night (hopefully) or tuesday morning (more likely) where Scott and Chip will then get to work preparing her for the next leg.

Assessing the situation and getting the work done as quickly as possible is crucial as we need to leave the dock wednesday and try to get way offshore.  Running the numbers for distance vs battery life on the upcoming leg, there is not a lot of wiggle room.  Each day in shallow water looks to be equivalent to about 2.5 days in deep, so we need to minimize the amount of time spent in the shallows as much as possible.

Tomorrow will be an early morning for our team both in the field and providing shore support.  To them we wish good luck

Force Wind Sea & Honor

3 Days until recovery.  Our field team is in place in Ubatuba going over their plan for recovery.  Tripped up by our batteries not making it to Brazil on time, Marcelo has very graciously not only offered to give us the lithium batteries from his gliders in exchange for ours when they eventually arrive, but his team has brought their glider to Ubatuba so there is a full suite of spare parts available to us if there is any staggering damage done to our glider.  When having a glider at sea as long as 29 has been and expecting to redeploy within a mere few days for the glider’s longest journey to date, collaboration with friends like this is absolutely crucial.

The waypoint has now been set in the direction of land and the plan going forward is to aim for the valley that lies ahead between the two hills reaching up to 70m as we try and avoid the shallower bathymetry along our final approach.

Force Wind Sea & Honor

With less than 90km remaining between Challenger and Ubatuba, we have halted our steam and taken up post just outside the 100m isobath.  The bathymetry that lies ahead of us has a number of hills and valleys and without a working altimeter, we would prefer to stick to this spot than push on further for the moment.  The plan now is to do our best to hold this location by bouncing between a number of tightly knit waypoints as the week remaining before recovery dwindles down.

The shipping traffic density plots continue to appear to be in our favor for the larger ships. Unfortunately there is a decent amount of fishing in this area as Dr Brandini pointed out, so we are doing our best to avoid getting snagged in any equipment.

Within the next couple days, the way point will be put on shore once again and we will make our final approach towards Ubatuba.

Force Wind Sea & Honor

Our good friend Antonio has done it again, filling our inboxes with spectacular images crucial to the success of this mission.  After doing some digging on the MarineTraffic website, Antonio was able to create a density plot of shipping traffic in the area.  From this, we are able to see a relatively safe path from our latest location to the endzone. Amazingly, this almost matches up with the Endurance Line defined weeks earlier- a good sign for future glider missions.

Antonio also sent along the 4-D ocean state visualization cube Pinzon, featuring sea surface height which depicts an eddy solar system to our south along the shelf where a number of warm core eddies are circling a cold eddy.

With the recovery now slotted for the early hours of Sunday May 18, our team makes final preparations for the main event.  Scott and Chip will travel down to Brazil on the 14th where they will soon meet up with Marcelo Dottori at the field station in Ubatuba.  While they get themselves on their way, Challenger will be set to cross the shelf and head in towards shore. Depending on our progress, we may pick a spot to loiter to kill time, but the overarching goal is to get as far in shore as possible so there is not a whole lot of time spent on the boat.  We would rather reserve that time for servicing on shore.

Until then, we will head shore ward just to the north east of our proposed Brazilian endurance line.

According to MarineTraffic’s ship tracking service, the South Brazil Bight is the place to be.  Over the past week or so now we have been monitoring the movement of ships around our brave glider and it has been a bit nerve racking to say the least.

Putting that nightmare aside, the results of the past week and a half of traversing eddies has produced something quite interesting:

Through the middle of that time period, lining up almost exactly where we were pushed to the south, there is a bulge of cold water rising from the depths.  The thermal structure of the water column certainly looks like that of a cold eddy, which would match more closely with what the MyOcean model showed throughout that time period.

Now that we are through that event, Challenger has made her way close to the shelf at about the 500m isobath.  From here, we will fly to the south parallel to the shelf for a few days before making our approach to shore.

Force Wind Sea & Honor

Probably the largest feat of the Challenger Glider Mission was achieved this week, as our budding fleet reached not only the 1,000th day at sea, but also flew the 20,000th km!

The Challenger Fleet has now succeeded in flying from the polar waters off of Iceland down to the tropical waters of the Caribbean in the North Atlantic and spanned the South Atlantic bridging Cape Town South Africa to the waters of Brazil by way of Ascension Island.

Taking a quick look at 29’s progress, she is continuing to cruise through the eddy we discussed in the previous post.

Over the past couple of days, the eddy has migrated to the North, its strong southern region seemingly pushing us off course a bit as it moves through.  Contrary to that, RTOFS is showing a better developed eddy who’s center is to our south, it’s strong side being the northern edge that also aligns with the dip in our path.

Another major event that occurred today was the final presentations for the Ocean Observatory Class- a course taught each semester by the founders of the Center for Ocean Observing Leadership, Scott  Glenn Oscar Schofield and Josh Kohut where a class of ~60 students break up into tiger teams to create their own research projects to pursue throughout the semester.  The final for the course is a research symposium held in the lobby of the Institute of Marine and Coastal Sciences where a special guest comes to review the student’s research.  This semester, Dr. John Manderson of NOAA attended as the featured guest and joined a number of IMCS faculty and staff in learning of the progress the students made over the course of the semester. Click here to see some of the research conducted.  View photos from the symposium

Dr Manderson watches as a group of students demonstrates their semesters research

There has been quite a buzz amongst the scientists down in Brazil as 29 makes her way south along the shelf.  The region we are presently flying through is notorious for eddy formation and researchers are keen on looking at the data as Challenger makes her way through the region.  Last week, looking at the models it seems we may have cut our way through the position of a potential eddy while we may be on the verge of entering a new one.

Looking at the forecasted structure of the water column, in the top few hundred meters there appears to be a strong clockwise spinning eddy while at depth there is a northward jet flowing along the shelf when inquiring the MyOcean model.  The RTOFS model on the other hand shows a counter clockwise spinning eddy at depth to the south east of the gliders location.  The eddy most evident in the surface layers of the MyOcean model will be a prime subject to delve into in the coming weeks.

Force Wind Sea and Honor

With just 500 km remaining between RU29 and the port of Ubatuba, our team is working to pull all of the moving parts together to make this mission a success.

By the mere luck of the draw, Dr Frederico Brandini of the University of Sao Paulo colleague of Dr Marcelo Dottori who will be the Chief Scientist running the recovery operation for 29, is on sabbatical here at Rutgers.  Brandini gave a fascinating talk highlighting his work at the University with ecosystems along the Brazilian shelf break that our team was eager to attend.  One topic discussed was the immense fishing that takes place along the South Brazil Bight- the northern portion being where the recovery is being planned.  After the talk he met with our team where he was able to point out where the main shipping lanes were and helped us plan our approach.

In the image above we can see the result of the meeting being the red line which leads from Challenger’s latest location south along the shelf and then crosses the shelf perpendicularly and makes a B-line in to port.  At the University of Sao Paulo, they have a budding glider program that will soon be monitoring the coastal waters of their region.

In cooperation with their program, Brandini and our team planned the location of that B-Line to be the foundation of a future long term survey to be run by gliders- similar to the Endurance Line that we have run off of New Jersey for over a decade.  If all goes according to plan. Challenger’s final approach into Ubatuba will be the first of many glider runs along that line.

As for the conditions forecasted around our glider now, At the surface both models are showing evidence of a cold eddy to our south and warm eddy to the north creating the strong flux at the surface that is confirmed by the surface drift seen by the glider.  Subsurface however, RTOFS shows that there is movement northward in the water column that MyOcean doesnt pick up .  This push north seems to hold true when compared to the depth average current calculated by the glider showing an overall northward resistance.

Force Wind Sea & Honor

They Shoot! … and they miss.

We can’t win them all, but the important thing is that Challenger has officially crossed the Southern Atlantic, the first complete crossing of an ocean basin in nearly 5 years!

Looking ahead, we are planning on flying a path roughly 750 km towards the port at Ubatuba. As of right now we are not sure what sort of boat will be available to us for recovery, so we will do our best to take care of our team taking part in the operations being led by members of the University of Sao Paulo, and get the glider as close as possible.  This way we aren’t waisting precious time on deck and will have more time in the lab assessing the condition of the glider and being able to make the necessary repairs for the following deployment.  For now, the plan is to still travel down to Brazil in mid may for the recovery and redeployment so we shall keep our fingers crossed as we navigate the final stretch into port and move the necessary equipment to our friends in the southern hemisphere.

Force Wind Sea & Honor

According to the currents being calculated by the glider, 29 has been seeing a consistent push northward throughout the water column.  This overall flux shows the currents at depth are strong to the north, redirecting our trajectory as we power forward towards shore. This flux we believe may be part of the Antarctic deep water that Antonio described during Silbo’s crossing from the Canaries to the Caribbean.  The presence of this water mass moving to the north is what we believe to be the reason why Silbo was unable to follow the intended path across the equator and into the South Atlantic and instead had to divert to the west.

This resistance however is not too worrying this time around as flying perpendicular to it is allowing us to make consistent progress to the west.  Last night we shifted the way point a bit to the south as we aim for our next goal: The Trifecta.

The Trifecta that we are shooting for is as follows:

1. Crossing of the Tropic Of Capricorn

2. Crossing of the Exclusive Economic Zone of Brazil

3. Leaving international waters concludes our crossing of the Southern Atlantic Ocean Basin

As we define the end zone, we look to the US and European current forecasts to see if we can attain our goal…

Looking at the currents, MyOcean seems to match more closely to what Challenger is reporting as it shows the entirety of the water column weaving to the north-northwest while RTOFS shows the outer edge of the near by eddies resulting in a flux to the south.

Force Wind Sea & Honor