Shout-Out to Our Classrooms!

One of the best parts about being out here is hearing from our shore-side partners!

And I do mean partners! Before setting out on this adventure, Climate Central teamed up with eight science teachers from six different schools...and most importantly, their students. Each of the science classrooms is using the SOCCOM floats to study earth science and how the climate is changing, and we couldn't be prouder of them!

But this relationship is symbiotic! They use our data, but they help us too! How? By adopting the floats! Through the "Adopt-A-Float" program, SOCCOM is allowing elementary, middle and high school students take ownership and participate in the science.

Now that we've deployed the last float, each of our floats has been named by the students, and each of them is successfully collecting data.

Here are the names the students chose and where their floats were deployed:

Float Number            Release   Deployment Location              School                           Float Name
SOCCOM01 12575  12/27/16  1255Z 057.338 S 068.293 W  Princeton Day School     RE Byrd
SOCCOM02 12573  12/28/16  0615Z 059.008 S 068.498 W  Princeton Day School     RF Scott
SOCCOM03 F0569  12/29/16  0348Z 061.991 S 068.818 W  Bear Tavern Elementary Titus
SOCCOM04 12545  12/29/16, 2150Z 064.189 S 069.101 W  Melvin H. Kreps M.S.      Southstar
SOCCOM05 12543  01/01/17  2145Z 066.383 S 074.468 W  Princeton University        Jorge
SOCCOM06 F0567  01/03/17  0056Z 067.258 S 084.231 W  Melvin H. Kreps M.S.      Kirby
SOCCOM07 12559  01/04/17  0738Z 068.289 S 095.441 W  Passaic Valley H.S          Darwin
SOCCOM08 12549  01/05/17  1941Z 069.666 S 109.093 W  Passaic Valley H.S.         Mann
SOCCOM09 12390  01/08/17  2043Z 068.249 S 128.484 W  John Witherspoon M.S.   Bell
SOCCOM10 12551  01/10/17  0522Z 070.651 S 136.483 W  Sandia Prep School         Sundevil Sam
SOCCOM11 12541  01/11/17  1016Z 072.346 S 146.343 W  Sandia Prep School         Sundevil Lion
SOCCOM12 12381  01/12/17  2243Z 075.644 S 156.968 W  Princeton Day School      EH Shackleton

John Witherspoon Middle School's "Bell" begins its journey

You can find all the data from the floats at http://www3.mbari.org/SOCCOM/AdoptAFloatviz.htm

It's exciting for the scientists on board the Palmer to find out the names the students choose and hear the questions they ask. Not only do the students get to participate in the deployment of the instruments, but now that the floats are returning data, these classrooms will be using the data directly from the floats (the same data that scientists use!) to understand the dynamics of pressure, pH, nutrients, and phytoplankton across the world's oceans.

Just being an observer on the Palmer has opened my eyes to a variety of new worlds - the macro-world of the Southern Ocean with penguins, seals, whales and icebergs as well as the micro-world of phytoplankton and nutrients that can travel across the world. This isn't my last post, but I hope through this journey so far, I've helped to open your eyes to these new worlds too, whether you're a student in the Adopt-A-Float program or you're a student of our world in any other sense!

Greta

Wait! First let’s talk about batteries and bladders!

I’ve gotten a few questions about how the floats work, and now’s as good a time as any to answer them!

How does the float control its depth in the water? 

Inside the float, near the base, there’s a bladder containing oil—mineral oil to be exact. The bladder has a pump that can either inflate the bladder or deflate it. Since we can’t change the mass, all we can do is change the volume. When the float needs to descend, the oil is compressed, using the pump. That increases the density, and the float sinks. When the float needs to rise, the pump releases pressure, and the density decreases, allowing the float to rise. This of course all means that the float itself has to have a very specific mass.

How long does the float “live”?

Technically, a SOCCOM float has enough battery life to take 268 profiles in the Southern Ocean. If we take a profile every 10 days. That gives us over over 7 years of data! Battery life isn’t the only thing that matters though. During the winters, the float is especially strained. Even with sea ice avoidance software, ice can still damage the float in stormy waters. The SOCCOM scientists will estimate the life of a float to be between 5 and 6 years—weathering 4 or 5 winters before it becomes unreliable or the battery runs out.

What happens when the float runs out of power?

When the battery dies, the float sinks sinks to the ocean floor, but sometimes, it can get washed ashore if it’s close enough to land. That’s why it’s got a sticker with contact information on it:

If someone finds a float, he or she can contact the scientists, and SOCCOM will retrieve and potentially be able to reuse the parts or learn more from the how it fared in the water. It would be great to be able to retrieve all the floats once they’re running low on battery, but ship time in the Southern Ocean is expensive and hard to come by. It’s far more cost-effective to use any and all ship time to deploy more floats, especially because the pollution caused by these floats is far and away less than any other data-collection method. Just think about a ship trying to collect all the profiles that a float collects! Just the fuel cost alone would be far dirtier than a float doing the job.

What uses the energy?

The lithium-metal battery inside the float powers three things: the bladder pump, the iridium satellite communications, and the sensors. About one half of the energy goes toward the pump; one quarter goes toward communication, and one quarter for the sensors.

P.S. We're about to deploy Sundevil Lion, named by Sandia Prep School in Albuquerque, NM!

Here's a photo of the float:

... and a photo of us together!

How Do They Work?

By now, you know that these SOCCOM floats open incredible windows into a vitally important part of our climate system, the Southern Ocean, but how exactly do they do that?

Let’s take a look. First off, there are the sensors.

Here’s a photo of the top of one of the floats with the sensors labeled.

To start, take a look at the temperature and salinity sensor. That’s the black tower that has the tall holes in it. Salinity is measured by measuring the water’s conductivity. If the water has higher conductivity, that means there are more ions in the water, which means a higher salinity. If you know the temperature and pressure, you can calculate an exact number for the salinity of the water from this device.

The temperature probe is actually called a “thermistor” not a thermometer. The traditional mechanics of a thermometer use mercury, but a thermistor is actually a resistor (a metal, ceramic or polymer) whose resistance changes very precisely with temperature. Put thermo- and resistor together, and what do you get? Thermistor!

The reason why the pressure sensor is labeled differently is because you can’t actually see it! It’s behind all the other sensors, but it measures the pressure of the water around the float, and from that you can calculate the depth.

Because the float has these three sensors (T, S, and P), scientists will say that this float has a “CTD,” which stands for Conductivity, Temperature and Density, and that’ll get you your bread and butter parameters that you need to know about the water in every profile.

The pH sensor is connected to the temperature and salinity sensor by a tube that pumps water over from the temperature and salinity tower. That means the pH sensor is measuring exactly the same water that just had its temperature and salinity taken. This pH sensor is called an “FET,” which stands for Field-Effect Transistor. You might know that transistors can be used to precisely measure voltage, but what you might not know is that the voltage this sensor measures is directly proportional to the pH of the water! The tricky thing with this sensor is being able to package it in a way that we can get reliable data at different depths, temperatures and salinities. This particular sensor has just the right packaging to keep it going no matter what kind of punch Southern Ocean packs!

Next up is the oxygen sensor, over on the right. It’s an optical sensor, and it works by shining a blue LED into the water. The fluorescence properties of the water are determined by number of O2 molecules around. With no oxygen content, you’ll have maximum fluorescence, but any oxygen molecules in the water will quench a certain amount of the photoluminescence.

The oxygen sensor is kind of a variation on the nitrate sensor, which is short, and looks a little bit like a whistle. Instead of just blue light, the nitrate sensor sends many different frequencies of light into the water and measures the absorption spectrum of the water across the different frequencies.

Last but not least are the backscatter and chlorophyll sensors which we’ll talk about together because they’re wrapped up in one package down at the bottom of the float. (Why are they at the bottom? Because they’re heavy, and we want the float to stay vertical as it rises and sinks!)

Here’s a photo of Steve Riser with Southstar, named by Melvin H. Kreps Middle School. Down by his foot is the chlorophyll and backscatter sensor. The chlorophyll sensor optically measures something called chlorophyll fluorescence, which is slightly different from chlorophyll itself. When we deploy the floats, we calibrate that sensor using samples that we’ve collected from the larger rosette-shaped CTD.

Here’s a photo of that CTD. There are two parts to it—the 24 bottles around the edge, and the sensors at the bottom. This photo was taken right before it went out that door and sunk to a depth of 2000 meters. At different depths, the scientists will close the bottles, one at a time, in order to capture water from different depths, all the while monitoring the sensor readings from the ship.

The cable that holds the CTD from the boat is conductive, so as the rosette sinks, we can watch the data come in from the sensors, meter-by-meter. If there’s something particularly interesting at any depth, the scientists can actively “fire bottles,” or close them, capturing the water at that depth, on its ascent.

The CTD can also be sent all the way to the bottom of the ocean (which sits at around 4000 meters below the surface). Sometimes the scientists like to do “deep casts” like this. We’ve done that twice now, sending along some styrofoam cups. At 4000 meters, they’re under a heck of a lot of pressure. Oceanographers tend to measure pressure in decibars because it just so happens that the numerical value for pressure in decibels is close to the numerical value for depth in meters!

Take at look at this poor old Styrofoam cup!

Next up: we’ll take a look at exactly what these measurements tell us about the Southern Ocean!

Greta

Ending 2016 at Rothera

As we approached, the British base, Rothera, we got our first taste of ice-breaking. It was thin sheet ice that stood between us and the Brits, the kind that took only a bit of pressure break. A long dark
crack shot down the ice in front of us. It widened quickly as we sailed forward.

The wind is fierce. I and a few of the scientists, including Stephen Riser, stood at the bow of the ship. Our hats, hoods, mittens, and heavy coats were doing their best to protect us from the chilling wind
that came straight to our faces and made our eyes tear up.

Every few minutes, we'd pass a pair of seals lying on the pancaked ice. They'd awaken from their peaceful nap in the summer sun, look up at us lazily and gave us a chiding roar. We couldn't really hear them over the sound of ice sloshing against our bow and the loud hum of the ship.

Rothera is the largest British Antarctic Survey base. There's an island just west of the Antarctic Peninsula mainland called Adelaide, and Rothera is located on the eastern coast of that island, so you can see the mainland from it. Once we docked, we stepped foot on solid ground for just a few hours. Each of us chose between taking a tour of the coastline around the base, the glacier, their marine aquarium, or their air facility. Ted and I opted for the glacier.

Up we went in the "Tucker-Terra," a monster Snow-Cat truck that conveyed us up the glacier to a snowy pass. The people working at Rothera take full advantage of their physical location. They're
rock-climbers, ice-climbers, skiiers, snow-campers, as well as scientists... and runners.

December 31st was the day of their annual 10k race. It took place on the runway at the base. The Rothera-rians invited the Palmer-ians to join in the race, and we gladly accepted!

Some of us even pulled together a 5-person relay team, (snagging first place in our division... by default).

In the summertime at Rothera, (which is right now), the sun never really sets. It might resemble dusk around midnight, but that's it. At 0300, it may as well be 0800. And it's bright... the ice and snow
reflect so much light. That makes it easy to spot the tiny dots that are actually penguins!

After our visit to Rothera, we returned to the ship and began sailing back out into the deep ocean. Our next float will go into the water later tonight. I'll keep you in suspense of the name...

I'll be back with a summary of how it goes and a walk-through of a typical float profile!

Greta