Archive for the ‘Atlantic Crossing’ Category

Scarlet’s 7,000th Kilometer.

Wednesday, November 4th, 2009

Three glider experiments looking through three breaks in the clouds.

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Oscar is posting updates on the NSF experiment on the Middle Atlantic Bight Blog.

http://www.i-cool.org/?cat=5

Here we'll focus on the two Trans-Atlantic gliders.  Teledyne Webb's deep thermal glider Drake is approaching its first test along the 26.5 N line.  There is a clockwise rotating eddy centered on the line at 51 W.  How Drake crosses right through the middle of this feature will be interesting to watch in the current vectors, how its track is deflected, and in the resulting temperature structure and heat flux.  Once past this eddy, Drake looks to have a tail current along 26.5 N all the way to the edge of this plot at 45 W.

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Scarlet crossed the 7000 km mark today, with it's current path length reading at 7022 km.

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The approaches to Spain and Portugal are shown here. The red circle is the area of uncertainty discovered this past weekend - the area we are working to avoid. The green circle is our target region for the end of November. The eastern side of the circle is 120 nautical miles from Vigo (orange line), and the western side is at the edge of the Spanish Exclusive Economic Zone, 200 nautical miles offshore.  Inshore of the vertical yellow line, a strong current heads south along much of the peninsula towards Lisbon.  This alongshore current is likely to be faster than Scarlet can fly.  We'll try to stay just offshore of these as we wait for pickup in early December.

 

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Zooming into Scarlet's local area, she is now just less than 200 km from Spanish waters.  We hope to follow the looping white line into the green circle, then spin around the eddy towards its shoreward side.  Once in this region, there are several options depending on timing.  We can either continue to spin in the eddy or head into the strong alongshore current to move along the coast.  Whichever is preferred for pickup.

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Drake’s first challenge along the MOC line

Tuesday, November 3rd, 2009

Drake encounters his first challenge along the 26.5 N line. He is about to cross the southern edge of a clockwise rotating eddy. The surface currents will be against him.  But Drake is a deep glider, diving to 1200 m.  We'll see how we do over the next few days.

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Scarlet continues to keep her nose pointed east as we move south with the currents.  The combination is a southeast track.  The objective is to use all of Scarlet's speed to fly perpendicular to all the current arrows, trying to move along the thin white line that takes it through currents to the east and then currents to the northeast.  The distance along the wavey white pathline to the Spainish EEZ (thin yellow arc) is 250 km.  The white line is extended into Spanish waters another 200 km, so that its total length is 450 km.  If we did 15 km/day, thats 30 days.  We likely will not keep this speed for the full 30 days.  The think yellow stright line marks 12 W.  This is the western boundary of the strong alongshore current that runs south, and the outer boundary of the vessel traffic we see in the AIS.  Crossing that boundary will like put is in a current that is faster than the glider, and we would be advected south along the coast towards Lisbon as we waited for pick up.

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Still trying to break free

Monday, November 2nd, 2009

That long Trans-Atlantic band of clouds persists, with the New Jersey shelf emerging on the western side.  Looks like high pressure and clear weather behind it, meaning clear skies for the NSF experiment that starts this morning.  Glad we have an ocean all those satellites can look at instead of cloud tops.

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Activities later in the day will focus on the Jersey shelf.  We'll set the Trans-Atlantic fleet here for the day.  Drake remains a rock star - heading east on the 26.5 N line.  And the waypoint was moved farther downstream to the east as we head across.  Next job this week for Drake is to slide the altimetry geostrophic current map a bit to the east so that Drake has about 1/3 of the map behind it and 2/3 of the map in front of it.

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Scarlet reported even stronger currents overnight.  Up to 34 cm/sec.  We are not out of this feature (eddy?, jet?) yet. One good thing is that we are following it closely, continuing to update Scarlet's flight direction to be 90 degrees to the currents, and keep her nose pointed east.  The other good thing on the ocean side is that the current direction did not change between 7 pm last night and 3 am this morning, but the currents decreased to 22 cm/sec. This could be a sign that we have crossed through the maximum velocity core, and we are moving through a shear zone with lower and lower current speeds.

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The third good thing is that in spite of the clouds, there was a small break yesterday that resulted in a partial Sea surface temperature shot.  Maybe today we'll see some ocean color that will reveal the nature of this feature.

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Some mighty fine piloting

Sunday, November 1st, 2009

Scarlet's noon surfacing returned much more favorable currents.  Down to 15 cm/sec, mostly south and a very little bit east.  With Scarlet pointed due east, and running 15 cm/sec relative to the water, our resultant direction over the ground was more like southeast.   And we used all of Scarlet's velocity to move us from a strong unfavorable current to a weaker and more favorable place.  We'll continue on this path for another segment or two.  Pretty nice piloting on a weekend.

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More surprises from the eastern North Atlantic

Sunday, November 1st, 2009

Scarlet sent us home some surprising news that currents had increased to 28 cm/sec to the SSW.   We have not seen currents this strong for weeks.  Yesterday's guidance from the altimeter had us in a region with virtually no currents.  Today's altimetry is different again, currents to southeast are back, but not in the form of an eddy.  Some of what we are seeing is the actual evolution of the ocean eddy field.  Some of it is caused by the sampling pattern of the altimeter.  Sometimes you have to wait several days for a satellite to pass near you to update your estimated current fields.  Regardless of why (actual evolution or undersampling) the roadmap is changing every couple days. Antonio's waypoint change to straight east yesterday turned out to be a very good decision. With this morning's reported current stronger than Scarlet's own velocity, the best we can do is fly perpendicular to this current until we break free.  Thats exactly what Scarlet did last night, and its what we'll continue to do today.  Distance to the Spanish EEZ is down to about 240 kilometers.

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Drake's reported currents also increased overnight.  He is riding a tail-current, making 30 km in the last 13 hour segment.  Time to shift his waypoint further east.

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OOI’s Ocean Observing Simulation Experiment begins

Saturday, October 31st, 2009

The Ocean Observing Initiative (OOI) has begun construction. For information of the OOI go tohttp://www.oceanleadership.org/programs-and-partnerships/ocean-observing/ooi/

The OOI has a large effort to build a mature cyberinfrastructure to support OOI and all ocean infrastructure. As part of that 6 effort and growing out of over a decade planning we begin. First things first, we toast with a Halloween pint, the three who got us here, John Delaney, John Orcutt, and Robert Weller. For this effort we are a small piece of the OOI, and we represent a small part of the OOI cyberinfrastructure team. We are teaming up with infrastructure being funded by the NOAA IOOS MarCOOS and the ONR ESPreSSO programs. For the next two weeks, we will be testing all the Planning and Prosecution software during an Observing System Simulation Experiment (OSSE). The OSSE software team is large but anchored by scientists/engineers from Rutgers, Scripps, Cal-IT, MIT, USGS, and NASA’s Jet Propulsion Lab.

We will be testing several distinct software programs (to be highlight in several blogs to follow in the next few days) trying to coordinate real assets in the field during windy rough November weather in the angry seas on the Mid-Atlantic Bight. During this week we highlight in a series of blogs the range of technologies we will be deploying. The observation assets that we will use are satellites including AVHRR, MODIS, GOES 11+12, FY1D, OCM, TMI+AMSRE, and AASTR. These images will be complemented with a full nested CODAR array. The in situ robotic systems will consist of a fleet of Teledyne Webb Slocum gliders complemented with a fleet of propellered REMUS and Iver AUV systems. These field assets are complemented with NOAA NODC moorings. For models, we are utilizing numerical models from U Mass Dartmouth (Avijit Gangopadhyay), Stevens Institute (Alan Blumberg), University of North Carolina (outer boundary condition, Ruoying He), Massachusetts Institute of Technology (Pierre Lermusiaux), Rutgers (John Wilkin), Jet Propulsion Lab (Yi Chao). These ocean models are complemented by the atmospheric NAM model. The model and observation data can be accessed through the our ocean data portal constructed by the Jet Propulsion Lab.

To follow along, go to: http://ourocean.jpl.nasa.gov/CI

A social network site will be unveiled on Monday to collate all efforts To people who use the ocean in the Mid-Atlantic, please send us your comments. Join the network at: http://cyber.marine.rutgers.edu/
Note this site will be cleaned but please come join the network to give us your feedback. We need your eyes and brains. Our goal is to collect all the goods, bads, and ALL suggestions to make the infrastructure good for those use the ocean. The next blog will talk about the status of the mid-Atlantic Ocean today.

Oscar & Scott (aka Scotscar)

Antonio Earns a Gold Star

Saturday, October 31st, 2009

Sitting here at my dining room table on a Saturday morning, I look out at 2 worlds.  Out the window is the center of Hopewell, the same streets walked by Charles Lindbergh. Staring at my wireless laptop screen, the internet takes me into the COOLroom, and the COOLroom takes me out to sea.

Checking on the North Atlantic Fleet, a band of clouds stretches all the way across the middle of the basin, separating the northern stormy weather from the clear skies of the south.  Scarlet is working on our second attempt at a summer Atlantic crossing along the northern route, nearing the Spanish coast and racing the coming of winter. Meanwhile, Drake is enjoying the sunny weather of the tropics on our first attempt at a winter Atlantic crossing on the southern route.  Peering out through the clouds on the left is the fleet currently deployed in the Mid Atlantic Bight.  Lets check in on them first.

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Zooming into the Middle Atlantic Bight of North America, and into the New Jersey coast, we have a Sea Surface temperature image showing us a series of eddies in the Slope Sea, interacting with the shelf water at shelf break. RU15 has reached the outer edge of the Tuckerton Endurance line and is on its way in along a well trod path. I remember back in 2003 when we ran the Endurance line for the first time for Steve Ackleson at ONR.  Yes, we were very worried we could loose the vehicle, but we also knew we had to establish the first glider Endurance line to demonstrate their value.  Now, in the robot world, the Tuckerton Endurance line is nearly as good as the safety of home. Its one of the most trafficed glider lines in the world. While RU15 is heading in, three gliders from the NSF experiment, RU05, RU21 and RU23, are flying out in formation to meet it. It is definitely the hottest collection of ocean optics ever deployed on a fleet of autonomous underwater vehicles.  One hope is to draw these gliders close for an intercomparison test over the weekend.

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The NSF experiment starts on monday, and the gliders are likely to be sent out in different directions. The website to follow along is  http://ourocean.jpl.nasa.gov/CI/.  We just submitted the Year 4 renewal for the Mid Atlantic Regional Coastal Ocean Observing System (MARCOOS) proposal on friday, so all 38 MARCOOS Partners are turning away from text editing and heading out to sea with us on this joint experiment.  Wendell Brown is coming down from the observatory lab at UMass to sit in the COOLroom next week to be the voice of IOOS on the video feed.  Typically we broadcast voice with the video only at noon to the 4H groups concentrated in the center of our country (the 6 million in the middle), but we are looking at 10 am for live broadcasts this week to fit with our usual MARCOOS conference call time. To this we add the DHS Center of Excellence for Port Security.  While NSF and IOOS focus on the environmental side, DHS will focus a security experiment in the exact same location at the exact same time.  The DHS folks need to understand what is going on in the environment to improve Maritime Domain Awareness, and the NSF/IOOS folks need to know more about the what the people are doing if we are to properly study and monitor urbanized environments.

Now back to the tropics.  The deep thermal glider Drake continues to amaze us with its ability to track a line in the open ocean.  We are resetting the web page this weekend to prepare the displays to be of better use to both us and the scientists working out of the U. Southampton (UK), U. Miami (U.S.) and Max Planck (Germany) on Rapid Climate Change.  The Southhampton program is on Meridional Overturning Circulation, or MOC. Their wesbsite is http://www.noc.soton.ac.uk/rapidmoc/ .  In this case the undergraduate students in our Atlantic Crossing class are way out in front of the professors.  The students have already contacted many of the scientists on the website and are talking about exchanges of data that will help Drake fly. Just as scientists and students in Spain and Portugal have been critical partners in our efforts to fly Scarlet across the Atlantic along the northern route, we are hoping the U.S. students make friends with the British students, combining their expertise to get Drake across along the southern route.  We find the U.S. students are diving into this without waiting for their distracted professors to catch up.

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Finally,  across the Atlantic to Scarlet and Antonio's story.  In the last blog we were all amazed by the rapid change in the guidance provided by the satellite altimeter.  The geostrophic currents in the image totally changed character in the space of a day. The route east located to our south was gone, replaced by a series of eddies that drew us to a more northern route.  The new eddy is circled below in red.

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Saturday mornings are a great time for me to head out to sea in the observatory.  I'm away from the office, my wife is at work, and our kids are sleeping in. Its a tradition I started with Hans Graber from U.Miami during the ONR Shallow Water 2006 Experiment.  On Saturday mornings we would both head out to sea together, Hans from his observatory in Miami and me from mine at Rutgers.  We'd meet on the NJ shelf and discuss the data we were both looking at, and what to do next with our ships, aircraft and gliders.

This morning when I logged in, I found an email from Antonio in the Canaries noting "THE LAST OBSTACLE".  The time for interaction is short during the week, essentially non-existent.  When you physically go to sea, everyone knows you will be intensely focused, and they leave you alone.  But when you go to sea virtually, they see your body is still in the room, and expectations are different.  Antonio was clearly trying to get my attention, and finally, on Saturday morning, I had the time to listen.  Antonio was heading to the beach for some surfing.  The storm we are watching in google earth was stirring up 7 foot waves in the Canaries.  But before heading down the beach, Antonio logged into his observotry, and checked on the datasets he was watching.  His data said the eddy was spinning in the exact opposite direction.  He sent me the image this morning and we put it into google earth. Antonio noted that the guidance from our usual altimeter product would lead us right into the strongest currents to the west, suggesting we go around this region to the south by staying on a straight east course.

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Adjusting the transparency of Antonio's map, and overlaying it on our standard geostrophic currents, we can see the area of disagreement.  If we were on a data assimilation mission, this is the region of greatest uncertainty, since we are not even sure which direction this eddy is spinning.  It is the exact region we would point the glider.  It would have a simple mission.  Determine the sign of the spin - amazingly basic information - but one of these global datasets is wrong, and that error will have a significant impact on the forecast is the wrong choice is made for assimilation.  But Scarlet's mission now is a race with the clock, we need to beat the winter, meaning we need to avoid the regions of highest uncertainty.  We made the decision to change the waypoint to straight east.  But on this Saturday morning, all the glider pilots were watching the NSF fleet.  They where changing the depths of the excursions and keeping the fleet together.   Significant email traffic on this so I did not want to distract them from their main focus.  We would need someone else to fly Scarlet.  Tina - remember Tina? Azores rescue? - was following along over the internet in Antarctica.  She's been down there for a few weeks prepping the Antarctic glider fleet for deployment on a NSF mission.  Tina logged in from Antarctica, took control of Scarlet, and redirected her on a route to the east just as Antonio suggested.  We hope Antonio enjoys the surf.  He earned his gold star for the day.

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Thinking back to Hank Stommel's 1989 fictional account of the The Slocum Mission http://www.tos.org/oceanography/issues/issue_archive/issue_pdfs/2_1/2.1_stommel.pdf, a futuristic look at the oceanography, I am even more convinced the future is now. For today's quote from Hank, we'll use, "There is nothing like the need to make decisions to lay bare areas of ignorance that are papered over in textbooks".  Today we found a sign error in one of the world's textbooks, and we are not even sure which one is right.

Next week we take another step forward in the tranformation with the start of the NSF OSSE on the Mid Atlantic continental shelf.  I wonder what we'll discover on monday.

An Anniversary is Noted

Thursday, October 29th, 2009

On October 29, 1992, Mike Crowley powered up Rutgers' new SeaSpace Satellite Data Acquisition System and tracked an overpass of one of the NOAA sea surface temperature sensing satellites.  It was our first use of the Coastal Ocean Observation Lab's control center, what has come to be known as the COOLroom. Today Mike reminded me it was not much of a room back then.  It still had no ceiling, some internal walls where still missing, and we had to wear hard hats to work on the computer. But on this day 17 years ago, the Coastal Ocean Observation Lab began sensing the ocean off the U.S. East Coast and has never stopped since.

Checking in on the Atlantic fleet, a band of clouds stretches straight across the Atlantic from the U.S. nearly to Spain. We'll need to check how this weather is affecting currents on the European side later on friday.  I keep seeing emails from Antonio specifically on the currents, so I know he is keeping a watchful eye on us.  Its good we have a distributed team.

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First closer to home, RU15 is about to hit its final offshore waypoint.  Its on a dual use mission.  It has the hottest optics package we ever deployed for the ONR mission, and its following the route to collect temperature data for the NOAA IOOS and NOAA Fisheries missions. It should hit its waypoint at the end of the Tuckerton Endurance line today, then head in for recovery.  On Friday we also deploy 3 gliders for the NSF OOI.  Glider party in the Mid-Atlantic.

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Moving south to Teledyne Webb's thermal glider Drake, we have hit the target latitude of 26.5 N and are heading east.  We are running Drake along this line to determine how gliders can best contribute to the programs to monitor the north-south exchange of heat in the North Atlantic.  The circulation is called the Meridional Overturning Circulation, abbreviated as MOC.  The rapid climate change scenarios are often related to changes in the MOC.  Drake is holding the line quite well so far.  For those of us that grew up in the shallow glider world, it is truly amazing to see how well a deep glider can hold a line in the open ocean.

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On to the glamour shot for Scarlet.  At 8 pm on Oct 29, Scarlet surfaced and reported she had flown a total path length of 6,900.43 km.  We'll round down to 6900.

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Zooming into Scarlet's present location, the altimetry map below shows the path planning shocker from the noon surfacing.  The geostrophic currents on the map have totally changed in character. The jet to the southeast is gone, and the eastward currents we hoped to ride along 42 N are down to zero.  Instead of the stronger currents being to our south, the stronger currents are now to our north.  Luckily, Scarlet was on an eastward heading, so the distance to either route is the same.  With this new information, we turned Scarlet northeast into the region with larger currents. According to this sea-map, the currents should be first to the northeast, and then to the southeast.

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The satelite Sea Surface Temperature map below is in general agreement with the altimetery.  Where the currents are northeast, we see warmer water heading north.  Where the currents are southeast, we see colder water heading south.

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Lastly the recovery planning plot.  Our first task is to get into Spanish waters by crossing the 200 nautical mile limit (thin yellow arcs) that marks the outer edge of the Exclusive Economic Zone (EEZ). As of 8 pm tonight, Scarlet is 269 km from the outer edge of the Spanish EEZ.  Once we cross this line, our job is to position ourselves in Spanish waters at a location that is most favorable for recovery.

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Atlantic Fleet Update

Sunday, October 25th, 2009

The IOOS glider and the Navy Glider where both recovered from the Mid Atlantic Bight testbed this last week.  Both provide subsurface temperatures to compareto fisheries surveys, both provided assimilation data for our three regional dynamical forecast models, and both provided test data from the new Seabird glider CTD.  The storm front with sever rains that we just experienced yesterday is moving offshore, and the tight storm over the western North Atlantic is heading towards Europe.

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RU15 remains in the water on the Middle Atlantic Bight Shelf, completing and ONR optics and data assimilation mission just before the start of the NSF Ocean Observing Initiative Experiment.

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Drake is heading northeast and is only 1/4 of a degree south of 26.5 N.  Once we hit this latitude, somewhere around 55W, we'll turn east.

 

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Scarlet has found some favorable currents within a few degrees of our steering direction. Her navigation calculations indicate that the current is flowing at 16 cm/sec, and she is flying at 20 cm/sec, both in the same direction, clicking off 10 km in the last 8 hour segment.  We'll continue this downstream direction at noon today.

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Zooming out on the atlimeter's surface current map, it is 390 km to the red target star, and 370 km to the edge of Spain's Exclusive Economic Zone (thin yellow arc).

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Path-planning saves time

Saturday, October 24th, 2009

Head and tail current situations are great times to assess your glider speed relative to the water.  At the 4 am surfacing, the currrent direction and Scarlet's flight path were both within 2 degrees of each other.  We made nearly 10 km in the 8 hour segment, with a breakdown that looks like 2/3 Scarlet (6 km/8 hours) and 1/3 ocean (4 km/8 hours).  If that holds for a full day, Scarlet is making 18 km/day by herself and 30 km/day if you add in the boost from the ocean currents.  If we stay at this radius in the eddy, and continue to use its clockwise swirl velocity, we can cover the 210 km loop to 16.5 W in about 7 days at 30 km/day.  If we try to go straight across the eddy using only Scarlet's own speed, the shorter distance is 165 km, but it now takes 9 days at 18 km/day.  Going around the longer loop to the north to take advatage of the eddy swirl velocity saves us 2 days. 

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