Posts Tagged ‘RU 27’

Preliminary Path Planning

Tuesday, June 21st, 2011

Hey all,

So this morning we were given a brand new mission:  Silbo, now to fly under the name of Challenger 1, will conduct the first leg of the Challenger mission, which is to have a fleet of gliders that circumnavigates the globe.  Challenger 1 is expecting to be deployed Thursday morning (June 23, 2011) out of Reykjavic, Iceland and work its way south over the next couple months to Las Palmas, Canary Islands, Spain.  In order to start preparing for this flight, we began looking at the hycom models of sea surface height with surface currents to try and get an idea of where we will have to steer this glider...

These over lays really show how difficult this mission may become.  In the map above, the black lines depict about where we want to keep Challenger 1 while on its mission as to keep it on the most direct rout possible to the Canaries, while staying far enough from main land Europe to avoid the heavy shipping lanes.

From these figures it seems starting out, the currents are going to pose a problem for us.  The Gulf Stream, which helped us so much during the 27 mission, now is our enemy.  Part of the tail end of this massive current peels off and goes north towards Iceland, meaning we have a number of currents going against us.

The following 4 links are gifs showing the water conditions south of Iceland that also show how tricky these waters will be.  All 4 depict a number of eddies that we will have to fly through.

Sea Surface Height

Sea Surface Temperature

Sea Surface Salinity

Currents

The figure below shows two possible paths that will put Challenger 1 against the least amount of resistance.

In the hycom model overlay seen above, we can see how we are really going to need to fight our way back and forth through the oncoming currents.  To add urgency to the matter, we are also in a race against the clock to conserve batteries.  Operating in cold water drains battery life faster than in warmer waters, so our need to get a move on will be priority.

However, we have a trump card.  Challenger 1 has the capabilities to dive to depths of about 1,200 meters (nearly 4,000 ft).  With our previous experiences of flying the two gliders, Drake and Cook, we know that if we fly deep enough it is possible to effectively fight unfavorable currents.  Keeping this in mind, we checked out the bathymetry of the region using geomapapp.  In the graph below, we have the bathymetry if we were to draw a straight line from Iceland to the Canaries, along with the map below where the red is shallower waters vs blue being deeper.

Luckily, we don't have to go too far to get to where the water is deep enough to really take advantage of the benefits of using a deep glider.  Some of these being that we can dive further to where the currents are not as persistent, and that because of the extended amount of time it takes for the deep glider to complete one undulation, the pump in the nose of the glider moves less conserving more battery.

That is all for now, and be sure to check for updates as Challenger 1 is expected to be launched early Thursday morning.

 

Nilsen & Oliver

Get a clue, Voltaire!

Tuesday, October 5th, 2010

There's a pretty famous saying by Voltaire, "We are rarely proud when we are alone." Clearly, he did not know Dakota Goldinger or Doug Webb.

Chelsea and I listened to Dakota tell his story about RU27's victory and recovery in Spain. At the end of Scarlet's mission he was able to travel to Spain and celebrate the end of the glider's long journey across the Atlantic with the group he had worked so hard with for so long. It was a HUGGEE accomplishment... something never achieved before in world history. (Way to go Dakota) ... and it was special to him because it was a mission that he had personally worked on for three years. When he and the group finally got to Baiona, Spain to celebrate and congratulate RU 27, among all the fun and honors and there was one moment that stood out in Dakota's mind. Doug Webb, the inventor of the Slocum glider was there.
"Once everyone went inside and the glider was just outside by its self sitting in the rain Doug walked up to the glider with no one else around and just touched it and stood there in awe of his glider that made it across the Atlantic ocean." This touched Dakota because you could just see the pride oozing out of Doug. It was amazing to see someone proud of their accomplishments. After such a ridiculous amount of dedication, that success has to feel pretty damn good. At that moment there was nothing more important to Doug than that gliders accomplishments.

That was the end of Dakota's story, but what I got out of it was that the whole experience kind of fueled Dakota's fire for oceanography and glider missions and everything that the experience was about. Being able to witness how that felt to Doug makes you think about how monumental all of it is, the COOL room, the glider missions - it made us realize that this is not just a simple grade or a fun class to take. WE'RE DOING COOL STUFF! (that is going to make leaps and bounds of relevant and valuable difference in the scientific world.)

So thank you for sharing your absolutely touching story Dakota, we're all looking forward to your "glider in the rain" moment one day :)

-Team Awesome

Us: 1, Barnacles: 0!

Monday, October 19th, 2009

Hello All.

Tonight marks the hurtle over a gigantic milestone in gooseneck barnacle research. From the basement of Mabel Smith Douglass Library, Brian and I finally conquered the barnacle JPEGS, capturing their size in a pixel-to-pixel ratio using the the ruler tool in the Photoshop program. We measured the theoretical, tangential diameter of the glider at the point closest to the sample barnacle, and then measured either the height or the width of the sample barnacle itself. Pretty simple.

The tricky part for us was figuring out how to successfully convert pixel measurements into millimeters. Luckily, there are conversion tools floating around the web, waiting to be found by a pair of eager researchers like Brian and myself. We fished for a bit, and decided to go with a .org site (...based on the mythical legitimacy of the .org genre of websites). The website we chose can be found here. Just put in your pixel measurements, and voila: mm, cm, km, whatever.

By using a proportions formula, that we hope we've set up correctly (...remember, we're biologists, not mathematicians!), we scaled 2 barnacles and a large cluster situated near the front segment of the glider, on the "R" side of the vehicle.

Here is an example of the formula we used (all measurements in millimeters):

Theoretical Glider Diameter/Actual Glider Diameter = Actual Barnacle Height/Theoretical Barnacle Height

"Theoretical" values represent the pixel measurements taken from the JPEG converted to millimeters. The value in bold was the one we were searching for.

We were surprised by the accuracy of the conversion. Our first test subject, Barnacle 1, measured a height - from first visible point of peduncle (stalk) to tip of cirri (featherlike feeding apparatus) - of 43.14 mm after conversion.

lepas anatifera

Lepas anatifera

Our barnacle books have told us that a full grown Lepas anatifera can clock in at around 40 mm! So, Barnacle 1 can be assumed to be a full grown parasite, secreting disulfide fluids with adult-sized vigilance and malice.

The cluster, comprised of 15 visible barnacles, measured 90.58 mm from top to bottom, slightly off-kilter, but helpful. The cluster takes up approximately a little less than half of the glider's diameter (212. 725 mm).

Our third specimen, Barnacle 2, was the sample from which we measured the average height and width of the capitula (flowerhead, or plated body) of the barnacles. The height of B2 was just shy of 30 mm (28.22 mm), and the width was 24.11 mm. The measurements for B2 are interesting because this barnacle rests on (or rather sinisterly cements itself to) the frontmost ring of the vehicle, the width of which is only 15 mm across in actual measurement. So, the capitula of Barnacle 2 is actually both wider and taller than the ring it rests on. The height of B2's capitula (28.22 mm) compared with the total height Barnacle 1, is about half of B1's entire length from tip of stalk to tip of cirri. Just interesting.

The specific measurements themselves, of course, are of vital importance. But, the main point we're trying to make here is: most of barnacles on the glider are full-grown, which means that they were probably residing on the glider itself for around 2 weeks before the photos were taken in the Azores. They also fit within size range suggested for a full-grown barnacle of the Lepas species.

Thanks, Sage, for showing us how to use the Photoshop ruler tool!

Goodevening everyone,

Amanda and Brian