Archive for the ‘Atlantic Crossing’ Category

Pinzon’s plan – heading downstream.

Thursday, November 26th, 2009

Cloud band has moved south, just below Scarlet's track.

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Here is our worst case vessel traffic image.  There is the intense north-south routes along 10 W, plus another couple of traffic routes running from Northeast to southwest marked by the two red lines.

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SST shows we are in some relatively warmer water, and to our east, we see southward flowing colder water.

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And zooming all the way in, but keeping the red traffic lines up are are heading northeast along one of the lines. Currents have been favorable this week, alternating between NE and very small. This has been making everyone happy on both sides of the Atlantic.  We are making some distance, getting ourselves closer to shore for next week's trip to Spain.

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Uncertain Seas

Monday, November 23rd, 2009

Our last course change over the weekend was to turn Scarlet towards shore in Baiona and Vigo.  Current speeds had dropped, and we saw our chance the head towards shore and try to get out of this southwest current that has been holding us back.  Currents reported by Scarlet this morning have now switched, and we see the first northerly flow in over a week.  Our waypoint is northeast, currents are northwest, we are good.  A positive development after a week of difficult navigation.  One very interesting development, in fact the first map I have seen like this along the entire trip, the overlay of the different current guidance products shows we have all compass points covered.  The satellite altimeters (black arrows) say the currents are to the SE.  The HYCOM model (white arrows) say the currents are to the SW.  The glider (white lines along the track) says the currents are to the NW. And we are flying Scarlet to the NE.  Today we continue to examine why our uncertainties in the state of the ocean are so high in this location.

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Small Steps Along a Historic Route

Saturday, November 21st, 2009

Tina changed Scarlet's waypoint from Antarctica last night and turned her to the Northeast.   I know, nothing particularly newsworthy about a scientist in Antarctica flying an underwater glider off the coast of Spain, except for yesterday's visitors to the glider lab at Palmer Station. Below is a picture of NASA Astronaut Neil Armstrong and his wife Carol (front row) sitting with RU06 (second row) and Rutgers scientists Brian, Tina and Alex (third row) in the Antarctic snow just outside the Rutgers glider lab.  The gray boxes are the glider shipping containers for the Antarctic fleet.  For the folks at Puertos in Spain, we just sent two of those same crates to Vigo filled with equipment a couple days ago.

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Another remarkable thing about last night's waypoint change was that it was based on ocean forecasts.  Antonio has a new glider pathfinder system he calls Pinzon, in honor of Martin Alonso Pinzon, the Captain of the Pinta.  Antonio noted that Scarlet was in a similar situation as Pinzon and Columbus back in February of 1493. Their story as Antonio told me is that the Nina and the Pinta had just suffered through a great storm where the Pinta was severely damaged, and were left struggling with strong westerly currents. Columbus chose the southern route with the Nina towards Portugal, but Pinzon, in the damaged Pinta, was dragged by the westerly currents, and could not keep up.  Pinzon decided to steer his vessel north rather than head try to fight the currents, and when the wind switched to the Southeast, he turned the Pinta towards Baiona.  

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For the last 4 days, Scarlet has been experiencing stong currents to the west and southwest, greatly slowing our progress.  We have been steering her generally to the north, zig zagging with the currents, fighting for every kilometer in the east direction while trying not to loose ground to the currents pushing us south.  We have only traveled 29 kilometers over the last 4 days fighting these currents.  But yesterday, we have forecasts from both sided of the Atlantic saying the currents would change today.  Antonio's pathfinding program reads the forecast data files and plots a best course, suggesting Scarlet follow Pinzon's route, steering north till the wind shifts and then heading east.  Based on the forecast for today, Tina turned Scarlet last night.  The 3 am surfacing has currents to the southeast, the first easterly currents we have seen in 4 days.  We hope this trend continues.

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 Checking the Navy HYCOM forecast, we see the currents are heading northeast over much of the region.  We turned Scarlet to fly directly downwind with these currents.  Our hope is to move us closer to shore for the pick up in early December.

 

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Comparing the HYCOM currents with the geostrophic currents observered by the altimeter, there is not a lot of agreement.  But there is a reason for this.  The geostrophic currents is the component of the current forced by the highs and lows of sea surface height.  These currents change very slowing.  HYCOM includes all the influences on the currents, including the winds and tides.  There is going to be a lot more variability in the HYCOM model than the geostrophic currents, and as we get closer and closet to shore, that variability will begin to dominate.  Antonio suggests it is time to start reducing the time between surfacings now that we are in the Spanish waters where the variability will increase.  When people are back in the COOLroom on Monday, we'll start the process of reducing the time we spend underwater, first from 8 hours down to 6 hours.  As we get even closer, we'll consider the next step down from 6 hours to 3 hours.  These steps are standard procedures for bringing a glider home.

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One good thing about the recent stormy weather is that the clouds are moving past us.  The clouds are now over the Spanish mainland, with a clear patch opening up over Scarlet.

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Zooming into a SST only image, we see Scarlet in a relatively warm patch if we focus on a west to east transect along 42 N.  Further to our east is a patch of cooler water moving south, and beyond that is a patch of warmer water moving north.  If we follow these currents around the loop, the northward moving leg flows right along 10 W with all the shipping traffic.  This is something we need to avoid, and another reason for choosing the northern route as did Pinzon.

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Looking further up into the atmoshphere, we have the map of the Jet Stream showing the sharp turn to the left it makes as it approaches Spain.

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Overlaying the jet stream map on the satellite images of the clouds, the jet stream is bring clear air from south of Greenland over Scarlet and cloudy air from the tropics over Spain.

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The surface weather chart from Oceanweather has stong winds along this path running across the Atlantic from Canada to Spain.

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The result is big waves.  At least the 30-35 foot (orange-red) waves are north of us.  We are in the green zone, around 20 feet.

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Checking the Puertos wave buoy, they are getting 5 m waves closer to shore.   We'll hope for a window with 2 m waves in early December.

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A New Roadmap from Spain

Monday, November 16th, 2009

Ever since Scarlet entered Spanish waters, she has been fighting with a strong current to the south.  Our usual geostrophic current maps derived from the satellite altimeter have not been of any help.  The currents calculated from space are not agreeing with what Scarlet sees on the ground.  Especially worrisome this morning was the strong current to the southwest running at 22 cm/sec.  This is something we cannot fly against, so we have to turn sideways to it, and find more favorable currents.  But which way to turn?  Should we run perpedicular to this flow to the SE and try to get closer to shore? Or should we try to the NW?  Guidance from our usual source, the geostrophic currents, can't be trusted.

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That means we must turn to the models, where all the forcing is included.  Just minutes ago Antonio sent me this result from the model runs he is looking at.  We find Scarlet is on the western edge of a strong jet up to 0.6 knots in speed that is heading to the southwest.  The current is too broad to cross without being swept back out to sea.  Our best alternative is to favor the NW route, even though it seems like we are turning back away from Spain.

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Below we zoom into the location of Scarlet at the edge of the jet.  We'll start this turn by heading more to the north at the 11 am surfacing.  

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EEZ+6

Saturday, November 14th, 2009

Scarlet completed the 11 am surfacing, took Antonio's waypoint from Tina in Antarctica, and headed off to the northeast. She is now 6 kilometers inside the Spanish Exclusive Economic Zone, otherwise known as the EEZ.  Currents are still strong but the direction continues to rotate counterclockwise - a good sign.  We hope this trend continues.  In the image below, the thin yellow arc now to our west is the offshore side of the Spanish EEZ.  The thin yellow line to our south is the border between the Spanish EEZ and the Portuguese EEZ.  The thin rectangles in the upper right hand corner are the shipping lanes.  Our mission now is to position Scarlet in a safe place for recovery.  The U.S. recovery team leaves New Jersey on Monday, November 30, and meets our Spanish counterparts in Vigo on December 1.

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Antonio in the Canaries has won the competition for the first reported communication with Scarlet inside Spanish waters.  But the science team at Palmer Station in Antarctica wins the competition for the first reported celebration in honor of the crossing.  After Tina transferred Antonio's waypoint to Scarlet and sent her on her way, she led the science team in a traditional Polar Plunge into the near zero degree centigrade waters of the Antarctic Ocean.  I know the water is near zero degrees because I checked the temperature being reported by RU25.

Scientist #1 (Tina) into the water:

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Scientist #2:

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And Scientist #3:

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After the plunge, the traditional warm up in the hot tub.  Hats off to the Palmer Science Team for their game winning entry.

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Honour All

Saturday, November 14th, 2009

That's how Antonio ended his morning email today. He was the first to see Scarlet cross over the line. Now he has the honor of making Scarlet's first waypoint change in Spanish waters.  As we get closer and closer to Spain, we will rely more and more on local knowledge.  Antonio has asked us to maintain a course to the northeast to compensate for the currents to the southeast.    Because ocean current speeds are nearly matched to Scarlet's own speed through the water, this will result in an eastward path over the ground for Scarlet.  Antonio and I continue watching the forecasts and altimetry products for guidance on current patterns.  The geostrophic currents from the satellite altimeter data we normally use tell us the current should have already turned to the northeast.  Clearly this is not the case.  This morning, Antonio sees that the products on his side have placed that northeast current some nautical miles still to our east.  We'll head towards that current with Antonio's waypoint for the 11 am surfacing.  Tina made the change to Scarlet's course from Palmer Station in Antarctica.

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Checking the rest of the fleet, Teledyne's Drake continues on its climate change mission, maintaining the 26.5 N section.  The agreement between the geostrophic surface currents from the altimeter and the depth average currents from Drake continues to amaze us.  The satellites say Drake just entered a southward flowing current, and thats what Drake is reporting.

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Back to the Middle Atlantic Bight, the coastal glider fleet (Rutgers & U. Delaware) is emerging from the trailing edge of Tropical Storm Ida.  The front between clear weather and clouds is passing right over New Jersey.  The rain has stopped, and people are out assessing the storm damage. Follow the Middle Atlantic Bight Blog at http://www.i-cool.org/?cat=5  for most recent updates.

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Moving way south to the Antarctic continent, Tina and Alex deployed RU25 this week from Palmer Station. Follow along on the Antarctic blog at  http://www.i-cool.org/?cat=21

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Spain!

Saturday, November 14th, 2009

Today we begin a new era of global ocean exploration. The Scarlet Knight has crossed the Altantic.

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Scarlet surfaced inside Spanish waters on Saturday, November 14, 2009 at 8:17 GMT (3:17 am EST).

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To our friends in Spain and Portugal, we look forward to seeing you in December for the recovery.

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To our families back home, 201 days ago on April 27, we launched Scarlet and dedicated this mission to you. Thanks for understanding.

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To our many partners on both sides of the Atlantic that made this possible, this has been a team effort that began over a decade ago.  It is success story shared by all. 

Thanks to all,

The R.U. COOL Team

2 Kilometers To Go

Friday, November 13th, 2009

As we discussed in the last blog, our time for crossing into Spanish waters would depend on the currents. If the currents turned to the east, we would make it across at tonights 7 pm surfacing.  If the currents turned to the south, we would have to wait for tomorrow morning.  Currents turned to the south, and remain strong at 15 cm/sec.  We were 6 kilometers from the line. We only flew 4 kilometers.  That leaves us 2 kilometers shy of the Spanish Exclusive Economic Zone (thin yellow arc). We have flown 7279 kilometers in 200 days.  We have one more 8-hour segment to go. What will 3 am bring us?

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200 Days at Sea. 6 Kilometers to go.

Friday, November 13th, 2009

At 11 am this morning local time, Scarlet surfaced and reported currents to the SE at 15 cm/sec.  So the current speed is still high, but they have rotated around counterclockwise, starting at South and switching to southeast.  If this rotation trend continues, it will align the currents more with the geostrophic currents, and it will push us closer to the Spanish EEZ.  Our glider heading was maintained at NE.

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Looking at the big clock, today is our 200th day at sea.  We have flown 7,275 kilometers. For flight distance remaining, we have measured it several times, and have discovered that precise distance measurement is not a strength of google earth.  Our best estimate is that we are just under 6 km from the edge of the Spanish Exculsive Economic Zone marked by the thin yellow arcs.  Our last segment covered a distance of 6.5 km.  We expect to be very close to Spanish waters at the 7 pm surfacing.  If the current rotates more towards the east, we cross.  If the current rotates more to the south, we'll be a few kilometers shy, and the crossing will occur at the 3 am surfacing. Either way, I bet we are watching.

12 kilometers and an unexpected current

Friday, November 13th, 2009

Just a short blog - wanted to get this over to Antonio in the Canaries right away. Looks like we all will be pouring over our guidance maps today.  Scarlet just reported a strong current 0f 13 cm/sec to the Southeast, almost exactly opposite to what we see in the geostrophic currents from the satellite altimeter.  Strong winds?  Inertial waves? Looks like Antonio and I will be generating a little email traffic in preparation for the 11 am surfacing.  This new current slowed progress to the east a bit.  We only covered about 4 kilometers, bringing us to within 12 kilometers of the Spanish EEZ as of 3 am (eastern standard time) today.

 

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