Gerhard's Journal: August 8 - August 22
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A log entry of August 2nd or 3rd describes the weather balloons that
Peter Guest of the Naval Postgraduate School sends up daily at 11 am and
11 pm. He is the atmosphere guy. Yesterday's log describes the weather
mast he had on the ice. The everyday kite, a là Ben Franklin, is
today's topic.
While we had access to the ice, or when the ship is stopped for an extended time near an opening in the ice, Peter flies a kite. The kite supports a radiosonde, just as Ben Franklin's kite held a key. He maneuvers the kite over the ice and over leads in the ice. The radiosonde records data on temperature, air pressure, and humidity while he flies the kite over these stretches of open water and ice. This is the short version on the kite: Peter's goal is to calculate how much heat is coming out of the lead; he does this by measuring how much warmer and moister the air is downwind of the lead. 
No long version like yesterday, unless you want the equation that Peter is working on which contains some constants and variables of temperature, wind, and widths of the lead. On the ice, kite flying is easier because of the open space. On the ship, he has to do his flyig from the bow, with the wind blowing away from the ship. He uses a standard, nylon kite with heavy duty line. For control, the line is attached to a deep sea fishing rod. Because the kite goes a tremendous distance in a short period of time, and because Peter wants to get in multiple flights over an area, a battery powered motor on the reel helps him haul in the kite. Typical flights reach 200 meters away (think two soccer fields) and 120 meters high (think an entire football field). Relatively low tech equipment, but some high powered results. |
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A log entry of August 2nd or 3rd describes the weather balloons that
Peter Guest of the Naval Postgraduate School sends up daily at 11 am and
11 pm. He is the atmosphere guy. While everyone else dunks devices into
the water and analyzes water structure, he records what's happening above
the ice surface. Peter has three other tools in his meteorological kit:
a weather mast, an instrument on the ship to measure short wave and long
wave radiation, and a kite. More on the kite tomorrow.
This is the short version on the mast: Peter's goal is to calculate heat exchange between the surface of the ice and the atmosphere. Here's the longer version: Long wave radiation emanates from all matter, but in the atmosphere, the greatest sources are carbon dioxide, water vapor, and clouds. The downward looking sensor measures the long wave radiation going up; essentially how much heat is being taken away from the surface. On the ship, Peter has upward facing sensors measuring the long wave radiation coming down from the atmosphere and the short wave radiation coming from the sun; essentially how much heat is being delivered to the surface. Now, add the affect of turbulent air (think about the air coming from a fan or blow drier) over the ice; essentially more heat added to the surface of the ice (in the same way turbulent water brings heat to the underside of the ice). Using all this data, Peter calculates the total heat exchange between the ice and the atmosphere. Whew!
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Ship Life
Rest; you gotta have it, even if a person wants/needs to drive himself hard. Most rooms have bunk beds, a shower/toilet, and dresser space for 2. While there is a desk and chair and a TV/VCR, the room is best suited as a place to change clothes, shower, and sleep. Principal Investigators usually have a room to themselves. The most senior scientists and the licensed crew members have their own rooms or small suites. The hallways bear reminders to be considerate and BE QUIET, because there are people trying to sleep 24 hour a day, due to the 24 hour a day schedules. Recreation; everyone needs diversions. Books...everyone brought some and the ship's library has 100's. Movies...many people brought some and the ship's library has 100's. Music...everyone brought some and the ship's computer houses 100's of titles. One lounge invites movie goers. A conference room has a library atmosphere. And a second lounge is set aside for smokers. The exercise room has a treadmill, bikes, a rowing machine, a stair stepper, and a complete weight machine. A sauna helps take the chill off if you've been outside a while. Thanks to Laura de Steur, the science group has occasional parties to celebrate a birthday, our work on the ice, or the half-way mark of the cruise. The captain and crew make the bridge a welcoming place. With the best view of the sea at 5 levels above the main deck, the bridge is another place to simply hang out and relax. Water vapor drifts upwards through cracks in the ice or from the wash off the stern. The landscape of sea ice is endlessly fascinating. At night, the darkened bridge, which allows for the best night vision, has a combination of mystery and safety whether it's a miraculously clear night or a stormy, snowy evening. Stunning sunrises and sunsets, which are protracted due to the low angle of the winter sun, invite pleasantly long gazing. Right now, we are enjoying views of a full moon.
Chores: they are inevitable, but minor. Everyone has to do their own laundry. And while the decks are swept and mopped, and bathrooms around the ship are cleaned daily by the crew, one's own room needs vacuuming and personal bathrooms require regular cleaning...just like home. Workstations, whether computer or lab bench, need to be kept tidy (or not)...just like the office back home. Annoyances; they are inevitable, too. It's winter in the Antarctic, so we crunch through ice. The noise is deafening in the galley, and can make it tough to sleep. Some kind of engine or fan is on all the time, so every room is filled with a low level drone. The ship is constantly taking data on current and the depth of the ocean floor. A very loud 24 hour-a-day CHIRP lets us know this system is working, and it can be heard on many of the decks. The human touch; thankfully, this is inevitable, too. Thrown together from different parts of the world and coming together with different backgrounds, 30 scientific and 24 ship crew members become a community. Individuals share their professional expertise and their personal lives. Topics range from the most technical oceanographic theories, to side-splitting tales of our children, to discussions about the arts and poignant stories. More pictures and information available at the Palmer's own website: http://www.polar.org/science/marine/nbp/. It's quite a ride. |
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Polar Oceanography, High Latitude Science, Arctic or Antarctic Research...all
these titles include at least one assumption about the work: it's going
to be cold. Even summers at or near the poles are awfully cold. Occasionally,
the bitter conditions can be avoided, such as working from the warmth
and safety of a ship or performing tasks in a heated hut or building.
During the ice drift phase of our cruise, one set of questions could only
be answered by getting right down into snow and ice.
Here are the characteristics of the ice Dirk Notz, from the Max Planck Institute for Meteorology in Hamburg, Germany wants to know whenever we can get onto a floe:
Dirk, aided by Dan Goldberg of New York University, drills lots of holes in the ice, spends lots of time kneeling on the ice, and pokes his hands and tools into lots of cold places. This team uses some fairly basic tools to get their data:
Dirk calculates the mean (average) for most of the above measurements. Here's what he's found so far; other measurements such as salinity require lab work or more calculations (the warmer jobs):
Remember, these are averages. On our last floe, a routine inspection found a 50cm thickness ten meters from a 15cm thickness. Think about that heat flux. That's enough energy to run a 40 W light bulb continuously. Are you amazed, like I was, at this "heat flux" through nearly 40cm of ice in an air temperature of -18.5oC; or that 3.2cm of ice could melt in one day? This happens because of the difference between ocean temperature (about -1.7oC) and air temperature: the "heat" of the ocean is escaping through the ice and snow layer, even 40cm of it. Small changes in ocean temperature, even a tenth of a degree, can make all the difference between melting, or more ice formation. Extra turbulence from wind or horizontal currents in the water can be another cause of greater heat flux. As sea ice forms, it "squeezes out" the salt, causing the ocean water to become denser and sink, also causing a mixing of ocean waters and heat flux. Those changes in temperature, wind, currents, or salinity can have widespread impacts on the ice and the ocean's behavior. There is a lot to know and understand about sea ice and its role in the ocean. It's a cold job, but someone's got to do it. |
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As an Elementary School teacher, the playground is an important place
for kids and it is a school-wide management issue. In a way, the ice became
the investigators playground. The ship was moored to an ice floe for almost
a week, and every scientist was involved in taking measurements from the
ice. There is a small chance we will get some additional ice time over
the next three weeks. And, yup, there are playground rules for us. Lots
of them.
A "Science Watch" is in place 24 hours a day with ice work. That means someone from the bridge is monitoring every person who leaves and returns to the ship, and the watch personnel can be in immediate contact with every science group member on the ice. Someone is routinely walking the ice on a regular basis, looking for cracks or shifts. The ship's crew on the bridge keeps a close watch on ice conditions, as well. These folks are like the principal, or the teachers on duty. Just as children are encouraged to enjoy the playground, the science party is encouraged to engage in their work or to watch others at work. However...don't forget the rules:
Is it really that dangerous? Yup. A crack in the ice can develop quickly. We found that out, multiple times. A fall through a hidden crack or hole is disorienting, and with temperatures and wind-chill into the -20 to -40oC range, even a short distance back to the ship can be impossible to negotiate. Whiteout conditions can develop rapidly, especially if a person is engrossed in work inside a hut, and getting back to the ship can be difficult. Individuals are prone to mistakes as they get cold or tired, or both. The parting words from John Evans were: "Don't do something stupid." Even if human endurance is willing, equipment such as winches or huts cannot always function in extreme cold and fierce winds. We've found out twice that having these rules in place made a quick evacuation proceed smoothly. No data, no science objectives, no piece of equipment are more important that a person's health and safety.
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The mixed layer floats and the ice buoys strike me as tools from the
arsenal of James Bond (see 8/8 and 8/9). The CTD appears to be the workhorse,
pumping out mountains of data on temperature and salinity during its 80+
casts (see 8/3 and 8/4). This next set of devices is a mixture of both.
A third mast of instruments, the variable depth turbulence frame, is lowered from the fore-deck of the ship and is attached to a computer-controlled winch. This allows the 25 foot long instrument frame to move up and down in the ocean slowly tracking features within the water column. Another computer controlled winch lowers a mast of temperature, salinity and microstructure sensors through a hole in the deck, called a moonpool. This hole goes through the hull, and allows devices to be lowered into the water from the stability of the ship's deck. This CTD/microstructure profiler moves up and down continuously, between 50 and 300 meters, looking for interesting (turbulent) locations in the water column. It's been coined the "Yo-Yo CTD." The data it collects will also "drive" the variable depth turbulence frame, on the fore-deck of the ship. Finally, later in the cruise, more profiling will happen over the fantail, which is the very back of the ship. 
The scientists who put these together bring an amazing set of talents to the lab bench. First, they are leading oceanographers with foundations in physics and math. The equations used to describe the ocean water look more like hieroglyphics than math. They must also be part inventor, electrician, electrical engineer, mechanical engineer, computer programmer, winch operator, and plumber. I also think it takes some childhood experience with Lego or an Erector Set. Miles McPhee of McPhee Research; Tim Stanton, Jim Stockel, and Bill Shaw of the Naval Postgraduate School; Anders Sirevaag of the University of Bergen (Norway), and Jamie Morison and David Morison of the Applied Physics Lab at Univ. of Washington are the contributors to this system. What are they trying to find out? Remember, the waters over Maud Rise are unique because historical data show large areas of thin sea ice coverage, or even enormous openings in the sea ice. These sensitive instruments, moving in different water columns and descending from different platforms, are looking at how the water is mixing at various depths; looking for changes in current, temperature, salinity, and pressure. This, in turn, helps the scientists understand the heat flux: the energy transfer between lower and upper parts of a water column. That's the flux part. The behavior of water and the heat flux is thought to be a clue to the ocean's distinctive behavior in the Maud Rise area. Well, it's getting old, but once again, cracks around the ship have forced everybody and everything off the ice. During the past 5 days, scientists made the most of the time we did have, especially these flux clusters. So we are off to greener pastures...well...at least a different part of Maud Rise. |
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Names mean a lot, whether they are for people or things. I'm named after
my father. The Grand Canyon describes itself well. In oceanography, the
CTD earns its name because it records conductivity, temperature,
and depth. What would you call a slender, sleek, black
device with shiny, stainless steel probes that look like fangs? It wears
a cape of black brushes near the top to help it fall through the water.
And, if this device made its debut on October 31, would that influence
what you might call it? The technical name is the Vertical
Microstructure Profiler.
With all that, it begs it to be called...Vampire.
The senior scientists at Earth and Space Research, Robin Muench and Laurie Padman, are using this instrument to add to the data about the waters in Maud Rise. While it may sound gruesome and looks a little like a weapon, this is an extremely sensitive piece of equipment. It drops through the layers of ocean water at 60 cm a second (2ft/sec). As it descends, delicate sensors constantly measure temperature, salinity, pressure, and currents in very, very small pockets of water, 2 cm3, or about the size of a die. The resulting data are high quality measurements of turbulent mixing rates. This turbulence is one key to understanding the water conditions that are so unique to this region. Remember, historically the Maud Rise has shown thin ice or large openings in the sea ice cover. Laurie, Robin, and Kristin Richter study the data after each cast to determine how deep to send subsequent casts of the Vampire, always "fishing" around for interesting parcels of water. In addition, this data will be compared to historical data collected from this area to see how conditions may have changed. Then, the data is added to ship's current collection to help decide where the cruise should go next in search of unstable water conditions. Finally, the data will go through more scrutiny in the home offices. Vampire deploys through a hole in the ice while the ship is moored to an ice floe. (Despite Sunday's cracks, we're hanging in here and everyone is back on the ice!) In this way, the device can collect data from different depths and different locations as the ice floe drifts with the current and wind. Because it requires constant monitoring, a helo hut (so named because a helicopter can transport it) protects the operation and the operators. Later in the cruise, Vampire will be lowered off the back of the ship (the fantail) while the ship is in small leads or large open water areas, called polynyas.
Like all these instruments, you just don't plug Vampire in. So, like many of the science crew, Laurie has to be part electrician, plumber, mechanic, electrical engineer, and computer programmer as he assembles, cleans, prepares, calibrates, repairs, and deploys this instrument. Throw in a short list of unforeseen problems such as grounding issues, sensor malfunction, and parts damaged in transit, and Laurie spent close to 24 hours (most of it in the hut on the ice) getting Vampire ready to swim. It's an ongoing process to make sure it accurately records data. And because it is so sensitive, expensive, and crucial to gathering data, he's part anxious and loving parent as well, even if it is a Vampire |
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It's not the kind of excitement you hope for.
The ethic of safety first kicked in, and we started packing up right away. Another ethic kicked in, too: cool heads prevailed. Science Watch, the Big Brother of Safety took control on the ship, doling out information, steering help in the right direction, and keeping track of people. Every scientist quickly and methodically began the task of getting expensive and valuable equipment out of the water and the ice. The Raytheon Techs zoomed onto the scene like paramedics at an accident and began loading sleds and the Zodiac with all the "stuff" that had been set out two days earlier. Why did this happen? No one can possibly calculate the thickness under every square meter of ice. As described a few days ago, picking a good floe relies on a recipe that includes observation, satellite data, weather forecasts, experience, and common sense. Ongoing examinations of the floe found thickness varying from 60cm to 16cm. It's those random thin sections that succumb to wind stress, the currents, or warm water. The ice goes from stunning scientific playground to hazardous area instantly. Everyone and everything got off the ice safely, a good ending to a potentially horrible story. There is, however, an obvious unfortunate side. The Vertical Microstructure Profiler, run by Laurie Padman and Robin Muench of ESR, had to come out of the water along with the helo hut that housed it. Peter Guest's weather mast, too, had to come off the ice. Anders Sirevaag and Miles McPhee's turbulence masts were also plucked from their holes, interrupting data collection. By this afternoon, less than 20 meters separated our old property line from the ice edge. This ice-drift phase of the cruise, planned to last 8-10 days, has now logged about a half dozen failed attempts at finding a drift from which to collect a week's data. Once again, I witnessed a third ethic: level headed problem solving. If my plans had been dashed, yet again, by the fickle nature of the ice or the uncooperative winds, I might resort to some public displays of a well-deserved emotion like frustration, anger, depression, or blame. To their credit, these scientists took their lumps, gathered in the conference room the next morning, and charted the possible next steps. Everyone got on to the business of deciding how to best continue collecting data, in the most important areas of Maud Rise, with the time remaining on the ship. Someone even joked that a floe lasting two days was a sign of steady improvement! With that excitement behind us, these logs will cover the instruments that were on the ice, and have found a way to continue despite this setback. |
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Ice Operation Logistics We found solid ice, or maybe it found us. The scientific playground
has been humming since late Friday afternoon. Here's a welcome summary
from Miles McPhee, the chief scientist: Subject: Plan of the day 14 Aug Sun 14 Aug 2005 Sunday All of the main Phase 2 instrument systems are deployed and operating. A hut is home to a vertical microstructure profiler (more on that tomorrow) that descends through a hole in the ice. A shallow turbulence mast and a mid-level mast have their own holes and are collecting data. A mast with a CTD is yo-yo-ing in the moonpool. A fourth mast is working over the bow, going into the water column at various depths (more on the masts on Tuesday). A meteorological tower is recording weather data. A brave crew continues to take numerous ice measurements and ice samples.
What does it take to set up and keep this kind of operation going? All the complicated scientific instruments deserve their own detailed explanations over the next few days. But what else? Well, there's a lot of stuff that isn't necessarily "scientific," like...heaters, lights, winches, generators (to run the heaters, lights, winches and computers), extra gasoline, transformers, long lines of power cords, long lines of data cords, wire fasteners, propane heaters, propane cylinders, different sizes of ice drills, an ice saw, ice axes, chisels, shovels, lots of rope, ice screws and toggles (to hold things down in the ice), steel cables, bamboo, bungee cords, tables, a chair, electrical tape, a snowmobile to cart things around, a sled with runners for heavy items, plastic banana sleds for lighter ones, an inflatable boat (Zodiac) for an emergency getaway, flashlights, strainers (for scooping out chunks of ice), thermoses for warm drinks, a whisk broom, good 'ole pen and paper, post-it notes, paper towels, various shapes and cuts of wood, a tool box, trash bag, grease, sponges, and yup...duct tape.
It takes a lot of clothing, like…sock liners, wool socks, thermal boots, thermal underpants, fleece pants, insulated overalls, thermal undershirt, fleece jacket, down vest, neck gaiter, an insulated float coat, face mask, ski goggles, a hat with ear muffs, glove liners, wool gloves, windproof and insulated mittens. Minus 20oC is cold, and with any kind of wind, it's a lot colder! Think of getting dressed and undressed as part of the commute time. It also takes lots of people. Marine Techs pilot the snowmobile, assist with loading/unloading, and provide tools or repair. Electronic techs maintain the generators, help with sensors, and provide electrical support. The Information techs make sure data is being stored, processed, and backed up. A science watch has a 24 hour eye on safety, keeping track of who is on or off the ship and continually checking the ice conditions. The ship's crew keeps the "hotel services" running to provide a comfortable return and assists in assessing the safety of our location. Here's another part of Miles McPhee's science update: "The amps weather forecast for 13 Aug was truncated at about 0600 tomorrow; however the imagery shows a pretty well organized system west of us. Today winds should pick up to about 20 kt from the NNE this afternoon." That's good news. The winds get the ice pack moving which could result in the interesting ocean conditions we hoped to find. |
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There's no such thing as a sure thing. Well, science at sea isn't a sure
thing.
Ultimately, the science gets done...most of it. Ultimately, students learn and achieve...most of them. Scientists and teachers continue to endeavor...starting with the best laid plans. |
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We are no longer a ship moving through countless miles of sea ice, taking
data and dropping instruments into the water as we go. Since Tuesday,
August 8th, we are part of the ice. During Phase Two, the ship is moored
to an ice floe with the intention of doing work from, and through, the
ice for the about 10 days. During this "drift' with the ice, a lot of
science will happen.
The goal is to remain lodged in the ice for at least 10 days, collecting data as we drift with the current and wind, right along with the sea ice. A drift of about 1 knot an hour is expected, meaning we will drift 15-25 miles a day. We are at this spot in Maud Rise because a drift was started here in 1994 which uncovered lots of interesting water characteristics. That drift was done as an afterthought because an ice camp was shortened due to thin ice. The resulting data was so interesting it lead to this cruise, a more in-depth study of the waters of this area. Preparations for this drift began as soon as we left Punta Arenas. As Phase Two of the cruise approached, the pace matched what parents do on a Christmas Eve. The weather and turbulence masts needed final assembly. The moonpool needed flushing. A hut that houses the microstructure profiler had to be constructed and furnished with a winch and lights. Naturally, computer programs were fine-tuned. Generators, heaters, and a snow machine needed checking. Ropes and sleds and boxes of all kinds required arranging and staging. The logistics of getting people and things on the ice, safely and in the most efficient manner, had to be worked out.
But, it's not as if the ship can simply set the parking brake at a certain longitude and latitude. As they say in the real estate business: location, location, location. For much of Tuesday morning, August 8th (chief scientist, Miles McPhee's birthday), the experienced polar scientists and the experienced pilots of the Palmer scanned the ice from the bridge. Oh, sure, they used radar and infrared satellite photos. But they relied on binoculars, keen eyes, and decades of experience to pick out a floe we could call home. They looked for, and talked about, things like grey patches and rough areas, relying on gut instinct as much as anything.
Ultimately, a small crew of these seasoned veterans walked the ice, poked holes through it, scraped through drifts of snow, and basically checked out the neighborhood. At 10:30, they had planted a few bamboo stakes that marked our new property. At 10:45, a crack snaked its way from a distant lead right to our ship, basically telling us to leave, and we were back to the home hunting phase. Thankfully, nothing had been unpacked, so it may have been one of those fortuitous disappointments. By dinner Tuesday evening, we had found a new location, the unpacking commenced, and some science work had begun. Wednesday promised to be a productive day of science, with only the weather mast, the VMP hut, and one of the turbulence masts still waiting their turns for final set up. But just as Tuesday's 10:45 crack signaled us to find a new place, 40-50 knot winds delivered more "vacate the premises" cracks in this neighborhood. Once again, we were sent packing, looking for another floe to call home. As I write, it's Thursday around noon and our search for a floe with which we can drift continues to a new section of Maud Rise. When you're out in the field doing science, whether it's a stream in your backyard or the middle of the Antarctic waters, the conditions are never guaranteed. |
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James Bond Oceanography, Part II: The Autonomous Ocean Flux Ice Buoys
We've mentioned a basic fact about ocean water: warmer or fresher water (less dense) tends to float on top of colder or saltier water (more dense). It is also true that the ocean receives many inputs such as wind, colder air temperatures, deep currents, and salt as it is squeezed out of sea ice. Therefore, water layers mix all the time. With this mixing comes an exchange of heat, the heat flux. The Weddell Sea is a fascinating place because these changes in ocean heat are thought to cause a thinning of ocean ice, and to have caused huge openings in the sea ice during the 1970's. How can you measure the movement of heat in the mixed layer? How about the Autonomous Ocean Flux Buoy? These buoys "float" on the sea ice, with the long section going through a hole in the ice. At the bottom, a probe is suspended 7 meters below the buoy measuring temperature and salinity. Next to it, a pole (mast) is placed through the ice, and it holds more temperature monitors. Together, this system can measure the heat flux in three ways: the heat conducted through the molecules in the ice; the heat moving the through the water layer under the ice (the difference in temperature between the ocean temperature and the ice temperature); the heat in small eddies of turbulence within the ocean water, in about 10 cm intervals. It's amazing enough that those measurements can be taken at all, but the sensors take these heat flux measurements 40 times an hour. As it "floats" in the drifting ice, the GPS unit calculates its position four times an hour. Every four hours, a satellite phone on the buoy calls the Naval Postgraduate School in Monterey, CA, delivering the data it has collected. The system at NPS automatically generates an email sending the data on to the scientists here on the Palmer. In the short term, the ship-based scientists can analyze the data to determine if it is worth going back to a certain location to further study the heat flux. In the long term, the buoys will collect 6 months of data to see if there is a major heat flux in the area after we leave. Four buoys will be placed in ice floes at strategic locations in the Maud Rise area. Getting these things in the ice is another mission altogether. People and equipment are hoisted and lowered to the ice by a ship mounted crane. The equipment is then loaded on sleds and dragged about 100 meters away from the ship. A hole is dug in the ice through which part of the buoy descends, with the top part "floating" on the sea ice. Imagine doing all that when the wind chill is about 40 below 0. After making sure the devices are "talking," the last delicate operation is backing the ship away, gently, so that no cracks are sent into the ice where the buoy has just been deployed. Even this smooth getaway is straight from Bond!
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James Bond Oceanography, Part I: The Lagrangian Float or Mixed Layer
Float
A basic fact of water is that colder or saltier water is denser (heavier) than warmer or fresher water. A basic fact of the ocean is that its waters consist of layers: fresher or warmer water rides over colder or saltier water due to the different densities. There is a "mixed layer" where these different densities mingle, ranging from a few meters to over a hundred meters below the surface. There is also a boundary where pressure, temperature, and salinity (and, therefore, density) change drastically. The boundary is called the pycnocline. Scientists are very interested in data in the mixed layer and near the pycnocline. So, someone invented a very cool device that can float right where they want: the Lagrangian Float or Mixed Layer Float. The device is programmed to float in a certain layer of ocean water. When it is first dumped into the water, it sinks slowly, monitoring the ocean levels as it goes. At the bottom of its fall, around 300 meters, a piston in the float changes the displacement of the device allowing it to float at exactly the precise depth or water condition, just as a submarine can rise or fall in the water. For this study, the float will drift just below the pycnocline (seeking a maximum temperature) and record temperature, salinity, depth, and pressure. Six of these floats will record these kinds of data underneath the ice for about two months, and then they will go to sleep. They are programmed to wake up on January 1, 2006, when the sea ice will have melted, and come to the surface. If that weren't cool enough, the float is equipped with a satellite phone. The phone automatically calls the scientists at the Applied Physics Lab at the University of Washington to check in, and to deliver all the data via the satellite phone. Here's another James Bond part, the orange skirt. When it's fully extended, it helps the float remain in the specified layer. The computer brains inside are connected to three small motors on the outer edge. When the float needs to rise or fall a considerable distance, like getting to the surface to transmit data, the motors pull the skirt in, or out, accordingly. That's what it will do for this cruise. Here's what else it can do; more James Bond. When it is deployed in open waters, it can pop up periodically and give its location, send data, and ask if it needs to be reprogrammed. With an internet connection, a scientist can change the depth at which it floats, or tell it to keep going. And if that's not cool enough, the float can be equipped with solar panels to keep it running. Once a week, the float comes up to the surface to be recharged by the sun. It is smart enough to know if it is charged enough for another week. If not, it will come up again the next day in order to complete the charging process. Pretty cool stuff. Eventually, the currents will ground the float somewhere. Occasionally, the finder will call the Applied Physics Lab and the lab will retrieve it. Other times, the float is considered lost and expendable. But, not after it has delivered important data about the ocean and its layers. |
