Archive for October, 2009

“A man without a goal is like a ship without a rudder.” -Thomas Carlyle

Monday, October 26th, 2009

This week we continued to take screenshots in order to track boat traffic and help us to predict where we need to pick up RU27. The beginning of the week did not show much boat traffic and the boats were mostly within the shipping lanes at 10° West.

October 21, 2009 2:22 am EST

October 21, 2009 2:22 am EST

There was not much traffic off the coasts of Portugal and most of the ships seen at this time were inside the shipping lanes.

October 22, 2009 8:37 pm EST

October 22, 2009 8:37 pm EST

We saw an slight increase in the number of vessels this day but again most of the boats were inside the shipping lanes.

October 25, 2009 2:25 pm EST

October 25, 2009 2:25 pm EST

Sunday also appeared to be a somewhat calm day at sea like Wednesday with a small number of ships and only one boat outside the designated shipping lanes.

October 26,2009 4:54 pm EST

October 26,2009 4:54 pm EST

Monday's shots could be seen as a potential concern. The week had not shown too much traffic and most had been within the shipping lanes but today we saw a large increase in shipping activity all along the coast of both Spain and Portugal. Many of the ships seem to be traveling farther out than 10° W.

October 26,2009 7:54 pm EST

October 26,2009 7:54 pm EST

Just a few hours later and the number of ships has once again increased. This shot is of high concern because of the large number of vessels outside of the shipping lanes. Over the coming weeks we will continue to track the shipping traffic and hopefully we can make a final decision on where will be best to pick up RU27 in order to avoid a possible run in with boating traffic.

-Amelia, Leo, Shannon

Oh wait, we lied.

Monday, October 26th, 2009

Hello All-

This is Melissa and Dani from the Waves group.  This week we found a couple of websites with archived weather data from Vigo, Spain (which is the closest city to our wonderful Capo Silliero wave-buoy).  This website, Weather Underground, has day-to-day records of temperature, humidity, pressure, weather and lunar cycles.  This will help us to determine the cause of the "scary" wave heights we've been seeing.  From what we have observed, the scary waves are due to long periods of overcast and rain/storms.

We also looked at a site recommended to us called Windfinder.  This gives us the wave and wind forecasts for the upcoming week.  This does not help us too much; although there is archived data, it comes at a price (literally).  We can at least use this site to forecast the wind patterns for the next week, and look at the Puertos del Estado site to compare the wind, weather and wave data.

From looking at the Puertos del Estado wave data, we are concluding that the waves aren't as scary as we previously thought.  Why, you may ask?  In the graph below of the wave heights from November 2006; the black is the average wave height and the gray is the maximum wave height for that day.  Here, the wave heights are, on average, between 2-4 meters:

picture-11 We can connect this data (from November 2006) to the archived weather data from wunderground.com to explain why the wave heights were so large or small.  For example, the biggest wave heights here are on November 27 and 28.  If we look at the archived weather data of those two days, we can see that both days had heavy rain showers.

From this, we can say that weather has EVERYTHING to do with waves.  If there is a storm, rain, overcast (what have you), there will be bigger waves.

That is all,

M and D

Data for Drake

Monday, October 26th, 2009

We found a data site that has plots of temperature, salinity, and pressure for an eastern boundary buoy at 23.8 degrees N, -24.1005 degrees E in 2005.  They have plots from 20m to 4850 m from the RAPID-MOC monitoring array.

eb1-3tsuThe above plot is a culmination of all of the depths but they also have individual plots from mid November to mid December in 2005.

We also put in a request for more of the mooring data since the data is restricted.

Additionally we looked over the plotted data for the glider mission in Sept. 2008 around the Canaries which includes plots of salinity, potential density, potential temperature, and pitch.

Lastly we looked at the gridded mooring data available for the western and eastern boundaries on the RADID-MOC array.  Below are vertical temperature profiles from April 2004-Oct 2007.  We would be interested in the Eastern boundary which in the bottom profile.

ts_gridded

The Season Begins!

Monday, October 26th, 2009

Palmer Station and the GouldGreetings from Palmer Station Antarctica. This year Alex (veteran from last year), Brian, and myself (Tina) are here for the LTER summer season. Some changes this year are the addition of a third person and a third glider to our group which will hopefully allow us to get even more accomplished. We will be working very closely with Maggie and Dan who are from Hugh Ducklow's group  since we are all sampling the same water and at the same depths. We will also be working closely with Kristen and Jenn who are the Penguin girls from Bill Fraser's group. Together the seven of us form the LTER science group! We have been spending the past week finding all our gear and setting up our respective labs. Today we are hoping will be our first sampling day however we are faced with a very high tide and 20 knot winds. Neither of which yields to successful boating. So instead we play it by ear and hope for a break in the weather.

Adelie Colony on Torgersen Island

It hasn't all been hard labor though... we were all lucky enough to go to Torgersen Island which has a couple Adelie penguin colonies on it. It was a beautiful day and quite the experience.

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.

091025_fleet_storms

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.

091025_ru15_sst

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.

 

091025_drake_alt

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.

091025_ru27_alt_zoom

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).

091025_ru27_alt

 

“Blood clots, I thought we were dealing with barnacles?!”

Saturday, October 24th, 2009

Hello All. 

On the surface, human beings and barnacles don't really seem to have much in common. Sure, we share a kingdom with them, but they're crustaceans and we're homo sapiens. We've evolved to possess the beautiful gift and curse of consciousness and barnacles, well, they've really perfected the art of sticking to things. 

The unexpected biological link between humans and barnacles becomes illuminated by answering a simple question of fluid properties. What fluids, besides barnacle cement, have the capacity to coagulate within a seawater composition? The list is short: blood and semen. Why is this significant to barnacle research? Human blood and barnacle cement don't seem to be related phenotypically (Brian's word), or aesthetically (my word), but genotypically, they are more similar than either of us imagined. 

When we suffer an injury resulting in an open wound, whether a cut by knife or a simple knee scrape, we as a humans rely on Human Factor XIII to form a cross-linked meshwork of fibrin to coagulate the blood seeping from the wound. Human Factor XIII is an important element in the stablization of the meshwork of fibrin, which are agrigation of thrombin, the initial coagulate protein. Human Factor XIII increases the stability of the previously existing fibrin-thrombin matrix, connecting thrombin monomers to fibrin monomers across polymer chains, as the picture below illustrates.

Human Factor XIII stabilizing a protein chain (source: Wikipedia)

Human Factor XIII stabilizing a protein chain (source: Wikipedia)

 HFXIII is that thin blue line connecting the blue dots from one polymer chain (one of the linear chains running horizontally), to the little red dot situated diagonally below the big blue in a polymer chain running parallel to the one above it. The sequence of the coagulate proteins (i.e. the thrombin, fibrin polymer chains) allows for cross-linking to occur on a diagonal plane, creating a meshwork that reinforces the bonds existing vertically between the polymer chains. 

Basically, HFXIII weaves the parallel polymer chains into a kind of protective biochemical fabric. And tada! human blood clots.

A hot new article in Science Daily, Super Sticky Barnacle Glue Cures Like Clots, suggests that the amino acid sequence making up the cross-linking protein, Human Factor XIII, is remarkably similar, and in some regions, identical, to the adhesive proteins present in barnacle cement. Fascinating stuff! For Rittschof, Dickinson, and Wahl, the researchers conducting the study, this means that barnacle adhesion could potentially be classified as a form of "wound healing." 

The biological connection between the parasite plaguing our poor Scarlet and our own bodies really hit Brian and myself pretty hard. We began to re-evaluate the way we had been approaching barnacle-fouling possibilities. Our entire focus on anti-fouling prior had revolved around aggressive chemical compositions of surface coatings. Our main question had been: How could we alter the chemical composition of the surface of the glider? But Human Factor XIII introduced the delicacy of chemical composition into our discussion. If one of the most important factors of barnacle adhesion also exists in a similar biochemical system in our own bodies, chemical composition seems like a delicate thing to be toying with. The biological consequences are now prevalent in our minds...

That said, here's our list for possible chemical bio-fouling techniques as of the moment. They don't look promising:

- urea

- monochloroacetic acid

-  polydimethylsiloxane

- trypsin-like serine protease inhibitor

Each of these possibilities is unsustainable for their own reasons. Obviously, we cannot coat the glider in urea and send it off into the ocean. Monochloroacetic acid is another liquid substance, and a halocarbon, which tends to be insoluable in water, but is also toxic. Polydimethylsiloxane used to be applied to boat bottom in oil form, but is also highly toxic to the marine environment. And a trypsin-like serine protease inhibitor would prevent the polymerization of fibrin into the first matrix of the diagram above, but couldn't possible be crafted into a material that could be coated on the glider to serve as a bio-fouling agent. So, chemically, we are at a standstill.

But, altering the topography of the surface of the glider itself, not the chemical composition of the coating necessarily, could be a viable bio-fouling option. 

Development and Testing of Hierarchically Wrinkled Coatings for Marine Anti-Fouling

This study suggests that altering the topographical surface of a vessel (or vehicle) could be an effective way to prevent bio-fouling up to eighteen months. But, Brian and myself are uncertain as to whether or not this topographical manipulation would actually be something that could be applied to a glider, given the potential drag and piloting issues that could result from a topographically hierarchical surface.

Scott, Oscar, Josh, anyone?? We went on a feverish search for our mentors to ask them about the possible benefits/drawbacks to an option like this, but everyone had mysteriously vanished... very Nancy Drew mystery novel.

 

Until next time,

Amanda and Brian

 

[thanks to Kunal for sending me the Science Daily article!]

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. 

091024_ru27_alt

 

Running downstream

Friday, October 23rd, 2009

 After running east with our head down to escape The Wall, we just turned Scarlet northeast at the 8 pm surfacing.  We have northeast currents along a northeast course. We'll run downstream until at least noon tomorrow.  To properly exit on the eastern side, we need to ride one of the outer rings of this eddy. The straight east course was running us a little too close to the center.  The worry is trying to fly due east out of the center - if you don't make it out in time, you risk spinning around for another lap.  The Wall already caused a delay, we don't need another.

091023_ru27_alt_2

Back in the Race

Friday, October 23rd, 2009

Scarlet has broken free of The Wall and is now has a series of four 8-hour segments with currents to the north, in excellent agreement with the geostrophic currents derived from the satellite altimeters.  The Wall explored by Scarlet is still not resolved in the altimetric data, which for us defines the scales of resolution we can expect for the rest of this trip.  We'll now use Scarlets velocity to head east, and use the clockwise swirl velocity of the eddy to spin us up to the north, over to the east, and back down to the south.

091023_ru27_zoom

Looking downstream in the altimeter data, we are about 430 km to our next target point of 42.0 N, 13.5 W, a point that is 5 to 10 km inside the Spanish Exclusive Economic Zone, depending on how you measure it.    We'll follow the wavey line of eastward currents in, so our path will be a little longer, but we'll get the boost from the currents. Assuming we make about 15 km/day from here on out, its about a month to get there.

091023_ru27_alt

If we look at the satellite Sea Surface Temperature map for the same region, we see a similar wavy pattern in the temperature front between the warmer oranges and yellows, and the cooler greens and blues.

 

 

091023_ru27_sst

Overlaying the two satellite products, we see good agreement between the two products derived from different satellites.  Its always good when views of the ocean from different satellites agree.  The cold water flowing south from the Spanish EEZ into the Portuguese EEZ is especially prominent.  We anticipate that the agreement between these two satellites is going to work in our favor for path planning over the next month.

091023_ru27_alt_sst

Moving over to Drake, progress continues to northeast.  We are 75 km from the waypoint, a distance that will be covered in about 4 days.   We'll adjust the waypoints to turn east once we hit 26.5 N.

091023_drake

Persistence Pays Off – Scaling “The Wall”

Thursday, October 22nd, 2009

 

A week ago starting on October 14, Scarlet came upon a counter-current on her trip east.  The westward flowing currents we not present in the large-scale geostrophic currents derived from the satellite altimeter maps of Sea Surface Height, and the area was covered with peristent clouds, blocking the view of the statellite infrared imagers that give us Sea Surface Temperature.  There was a small scale feature out there, and our satellites couldn't see it.  All we had for guidance was the data Scarlet was collecting herself.  Over the next week we would use Scarlet as the explorer, and learn that this small scale feature was actually about 80 km long.  It also would be given a name by people working in the lab.  It came to be known as The Wall.

091022_ru27_4_attempts

It took 4 attempts for Scarlet to cross The Wall. The first was on October 15 when she encountered strong currents to the west that slowed her progress towards Spain to a crawl.  We did have guidance from the satellite altimeters that this westward flowing current extended a couple hundred kilometers to the east, so there was no way to burst through.  We had to go around.  Going around to the south meant warmer water that promotes biological growth and increasing our distance from our targeted pick up point.  So Scarlet turned north, flying perpendicular to the westward current in a sweeping arc for a second attempt 3 days later on October 18.  This route showed promise, with a report of nearly zero currents at one point.  We expected this would be the front we were looking for, something that identified the strong sheer zone we expected to find between strong westward flowing currents and strong northward flowing currents.  But 8 hours later, these hopes were dashed with a report that the westward currents were back, and even stronger.  We went back to flying north, and letting the currents advect us west.  Two days later, on October 20, the first clear satellite image came in, it was digitally enhanced, and we got our first look at The Wall from space.  It was a clockwise rotating eddy that was not being resolved by the satellite altimeters.  We saw the eastern edge of the eddy was only a few 10's of kilometers away, so we again turned Scarlet east for our third attempt.  Again, we encountered strong currents that stopped us dead. We were pretty dissapointed by this news, but we have also been in these situations before. We turned Scarlet north again, persisting in our efforts to explore The Wall and find a way through.  Then earlier yesterday we began to detect a change in the currents.  We saw the current directions switch from flowing mostly to the southeast to almost due south.  That meant we were approaching the outer edge of the eddy on its western side.  With our hope renewed, and for a fourth time, we turned Scarlet east starting yesterday at noon.  This time we would be heading for a distant waypoint so that Scarlet would use all of her energy to just fly east towards what we hoped was the eastern edge of The Wall.  Then, this morning, at the 4 am surfacing, Scarlet reported a nearly 180 degree shift in the current direction.  Currents were now flowing nearly straight north, and are back in agreement with the larger-scale altimetry maps.  After a week of exploring, we had found the eastern edge of The Wall and crossed through it.   Surprizingly the sheer zone between the two water masses on either side is only a few kilometers wide.  Probably the location of a big biological party. 

Thanks to all our partners on both sides of the Atlantic that provided guidance data during this most difficult week since the Azores. Today we begin the recalculations of arrival times.