I-COOL

It happened. Again. Just like last year.  That special day in a teachers life when your students demonstrate they are ready.  You've worked all year for it, never quite knowing whether the transformation would really happen or not. Would this year's group of students rise to the occassion?  Would they form a team that can accomplish more than any one of them individually? Or is the whole idea of undergraduate students trying to fly an underwater robot across the Atlantic unrealistic?  More than once over the past three months it seemed like the last of these three questions was winning.  But one thing we have learned - Even when it seems like the wrong side is winning, you can't stop.  You got to keep going. And keep trying. Keep talking. Keep blogging. Keep flying east. Because if it does work, and the students catch on, you have done your most important job.  And you have accomplished the primary goal of this mission - Education.  Its why NOAA sent us across in the first place.  Its why Teledyne Webb Research chipped in half the money.  Its why the Rutgers alumni are one of our largest contributors.  Its not just about this glider and this flight.  All of the people directly supporting this mission believe in the importance of science and engineering education for our young people, and that we need to prepare them to live in a global community.  And thats why we build gliders, and with the help of our friends on both sides of the Atlantic, try to build the community that will fly them across.

So what just happened 3 months into this flight?  It was Dave Kaminsky's email late last night. I count eight "!" in his email.  Last week, Dave was looking over all the RU27 heading and yo data.  We had talked about the glider starting to show some heading variations at the top inflection points in its dive profile. Colin, another one of the students, was plotting up the glider temperature data, and they noticed this was occuring at the base of the thermocline.  On Friday last week, Dave asked permission to deepen the top inflection depth.  We had tried this once before, and we knew 50 m was too deep, resulting in an abort due to too much pressure pushing the pump back in.  We told him we would try his test in small increments beginning on monday when people were around to watch it.  Dave and the other students spent the weekend watching and steering.  Each had a job.  Anthony was watching the fin offset to make sure we minimized our average heading error.  Colin watched the CTD data and Dani worked on currents. Nilsen monitored the satellite coverage and the storms. Shannon and Dakota watched the glider speed.  Emily, Shannon and Dave did the path planning.  Dave changed the waypoints, taking over the job from Tina.  On monday, Dave got to try his test.  He pushed the depth of the top inflection from 35 m to 40 m.  The students sat in the COOLroom, waiting for the telephone to ring signalling an abort. But it didn't ring.  It flew the full, 8 hour segment.  Dave's new depth test worked.  It flew below the thermocline the entire time.  Anthony's setting for the fin offset resulted in average heading errors of less than 1 degree.  The glider flew 25% farther in this test 8 hour segment than the previous segment. The students had succeeded at increasing the dive depth and adjusting the fin offset, resulting in better tracking of the heading and more distance made good.  They had done it.  The students had designed an experiment for a robot 4,700 km away in the middle of the North Atlantic, and it had worked.  The evening emails announced their results.  The transformation was a step function.  It happened in the middle of the night, with that one discovery moment when they suddenly realized they knew something that no one else knows.  And they were going to announce it to the world with exclamation points!

Then the importance of the global viewpoint came through with a series of emails from one of our collaborators across the Atlantic, Antonio Ramos from the Universidad de Las Palmas de Gran Canaria.  Antonio operates a satellite data reciever at their University, and is part of the network of ground stations providing path planning data for this flight.  The U.S. ground stations can only see the satellites over the western half of the Atlantic, so we rely on European ground stations for the full resolution data over the eastern half. We have been recieving their satellite sea surface temperature feed for some time, but recently Antonio started compositing and sending us the MODIS ocean color data he collects.  The summertime heating of the sea surface often blurs the temperature signature of the warm and cold eddies we are searching for.  The ocean color shows us the phytoplankton distributions, and it is in these distributions that the eddy field lights up, especially in the summer.   The eastern North Atlantic was having some clear weather, and Antonio was emailing image after image with growing excitement as the eddy field was revealed one satellite pass at a time. Dave and Shannon just took the images Antonio sent us and flipped them into Google Earth.   Below is the most recent. The eddy field along the entire path between RU27 and Spain is visible in the changing phytoplankton concentrations.

Zooming in a bit to the regional scale around the Azores, I've highlighted two features in the ocean color image.  The long dark blue feature that runs north south along 32 W is highlighted in green.  A faint light blue feature to our southeast is highlighted in red. Both of these represent advection patterns illuminated by the biology.

We now take those lines highlighting the biological fronts and overlay them on the physics, namely, the geostrophic currents from the CCAR satellite altimetry product.  The alignment is perfect.  The long dark blue feature along 32 W is perfectly aligned with the clockwise circulation in the eddy (light blue) to our northeast.  The red line shoots right between a group of two clockwise eddies (green) and one counterclockwise eddy (dark blue) to our southeast.  Our confidence in the roodmaps just shot up.  Knowing what lies ahead changes the game.  We know where we want to go and what our options are for getting there.  We are no longer just reacting to what the glider is reporting.  We can plan.

Zooming in again, we move to the immediate region around The Scarlet Knight, indicated here by the RU27 tail fin.  The currents are starting to turn to a more favorable direction as we move into that lighter colored band of water that is flowing in between the three eddies. Our waypoint is perpendicular to this current, and flying us more into this band of phytoplankton. But as Dave noted before, we'll try to stay below the thermocline where most of the phytoplankton is concentrated.

Also in this image, we plotted last years track of RU17.  RU17 was lost after 5 months and 1 week at sea just 20 kilometers from the Azores territorial waters, shown here as the thin yellow arc. RU27 is currently only 40 km north of the last reported location for RU17,  and about 46 km shy of the Azores territorial waters. It took us 5 months and a week to get there with RU17.   We are only 3 months and 2 days into the mission of RU27.  Scarlet remains a fast glider.

This entry was posted on Wednesday, July 29th, 2009 at 5:33 am and is filed under Atlantic Crossing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.