I’m writing this on Friday morning because Thursday was so busy I didn’t have time to collect my thoughts enough to write this.

Harper had a great day yesterday! He recovered all three of his moorings in one day. The winds did indeed blow the ice away from Harper’s site so it was decided to go for it while the getting is good. During the 8:00 a.m. briefing, there was a fog that limited visibility to only about 150 m so it was decided to triangulate the position of his mooring to within 10 m. The triangulation took about an hour so the sun had climbed higher and hotter into the arctic sky. The fog had thinned enough to see almost to the horizon. It turns out we didn’t need such good visibility because the floats popped up to the surface just a couple hundred meters in front of the ship just as they were supposed to. Healy 2, the small recovery boat, ran out a line, hooked the mooring float to the winch and the mooring crew went into their dance routine. Harper’s first mooring was missing the thermistor string off the top which means it had some how gotten ripped away by the ice over the winter. The data logger was still intact so he was able to quickly down load the temperature data and found that the string lasted until November 14. He soon generated a graph of the data that shows the changes in the ocean water temperature with depth just below the ice as the ocean freezes. This is important stuff because it is so difficult to get data just below the ice and this layer is central for understanding the relationships between atmospheric storms (winds), sea ice motion and subsurface ocean currents.

Along with the data recorder for the thermistor is a microcat. I don’t know what microcat stands for but it’s a small unit that measures CTD, Conductivity, Temperature and Depth, just like the CTD scans they perform almost every night. CTDs are the standard oceanographic measurements because from that the seawater density can be calculated and density difference is a major driving force of subsurface ocean currents.

The next instrument on the mooring line to come out was the ADCP. ADCP stands for Acoustic Doppler Current Profiler. This device sends out pings, pulses of sound waves, and then listens to the echo that comes back. When the reflector of the sound wave is moving, the return pulse is Doppler shifted. That is, the return pulse’s frequency is slightly higher if the reflector is moving towards the instrument and slightly lower if the reflector is moving away. From the amount of frequency shift you can calculate the speed of the reflector. The ADCP has four beams so it can also calculate the direction of the reflector. Usually the ADCP listens for return pulses off of bits of marine organisms drifting in the water, which ultimately gives current. Along with subsurface water current, Harper is using the ADCP to measure the velocity of the ice above the mooring. His second mooring ended up in deeper water than he had originally hoped for so he is concerned that maybe the ADCP was too deep to get accurate reflections off the ice far above. He won’t know until later this year when he has time to carefully analyze the data.
Under the ADCP is the MMP, McLane Marine Profiler. This baby has a motor in it so it can power its way up and down the mooring line measuring CTDs and ADCP all along the line. These guys do it all. Because they do it all they are also expensive and fragile. Fragile is not something you want on board a ship with heavy equipment which could potentially bang around if the waves were to get large so MMPs have to be treated with love and respect.

After the first two moorings were recovered I got to go to work washing the gear with fresh water and preparing to pack it away for eventual shipping back to Fairbanks. Dave Leech, a mooring tech with UAF, gave me advice. His tips not only saved me time but I’m sure I would have been rolling around the cargo hold with severe back pain if I had tried to muscle the acoustic releases into the storage cage doing it my way. Dave’s been doing this for quite some time so I was grateful that he spoke up and saved me rather than stepping back to laugh. By the time the acoustic releases were packed away, some of the microcats had downloaded their data. Emily Shroyer took charge of that task. When she finished with each download she marked them and placed them on a bench for me to open and remove the batteries so they could be safely packed away.

Just before dinner, Harper and I managed to untangle his surviving thermistor string. We took it up onto the flight deck so we could spread it out and then separated the mooring line rope from the wire with the actual thermistors. When I first looked at the tangled mess thought for sure I would be missing dinner if I were to finish with this task before bedtime. After we got it spread out a bit the twists and turns weren’t so formidable and we had it all separated and neatly coiled up within twenty minutes. That sure made my day. I get nervous when I think something might get in the way of all the wonderful desserts served at dinner.

Dinner and dessert gave us all the energy we needed to retrieve Harper’s final mooring. The crew had it all on the boat by a little after 8:00 p.m.. The ship did three retrievals in 12 hours. It was a great day! My day and that of the mooring crew was not yet done however. Harper and Emily still had to download data from the last mooring while I tried to help the mooring crew clean up the deck to make room for tomorrow’s work. A shower and a trip to the galley for a late night snack made the perfect ending for another great day in the Arctic.

~John Petersen

It’s been a relatively slow day for science aboard the Healy today. Last night we steamed back towards Barrow overnight and then the CTD crew went to work through the morning taking data out and across the Barrow canyon.

When most people think of Barrow they think of flat, flat, flat. Oceanographers think of the famous submarine canyon that is just off shore following the coastline along Barrow. Water from the Bearing Sea funnels into the Arctic Ocean through this canyon carrying nutrients. The bottom of the food chain thrives on these nutrients and of course the higher organisms follow the little critters. Man then follows the big critters, seals and whales, and that’s why there is a Native settlement at Barrow.
By lunch time the CTD crew had finished so we went back to Barrow to let our distinguished Naval guests go back to their other admirable duties and we made tracks to deploy one of Kate’s hydrophones.

Being near Barrow aboard the ship can be a treat because we can get cell phone coverage. I called my daughters to see how life is going for them and then I went up to the bridge to let George Neakok call home. George’s six year old answered the phone and did not recognize his garbled voice over the poor cell phone connection so she told her older sister that someone was on the phone who said he was Daddy. His little girl then politely asked him if he would like to speak to her sister.
I spent the most of the rest of the after noon up on the bridge with George and listened to his stories of growing up in Barrow. I especially enjoyed learning about what goes into a successful whale hunt. They have to drill their young men almost as if they were in boot camp to learn to work together as a team. It takes discipline and teamwork if they expect to quietly paddle a small skin covered boat close enough to a 70-foot whale in a vital spot. He continued by explaining the process of butchering a 20-ton whale. It can take as much as three days to cut up a large one. Preparation and making skin boats is also hard and time-consuming work. Only a skin boat will do, as a modern aluminum or fiberglass boat will be too noisy. Skins from bearded seals are best for the covering and the hunters have to be careful to shoot the seals in just the right spot in the belly or the bullet holes in the skin hide covering will eventually leak even if they are sewn up tight. When I asked about head shots, George said that if the seal is shot in the head it will quickly sink and all is lost.

Now that Kate’s hydrophone is in the water we are heading out to Harper’s and Bob’s line of mooring sites. There is currently a bit of apprehension over whether or not we’ll find ice covering the outer most sites. The last sea ice satellite images show pack ice over some of the moorings but there are currently 25-knot winds blowing the ice away. I’m just hoping it’s ice free and the winds stay calm enough to start retrieving tomorrow at 8:00 a.m.

During this cruise I’ve had the pleasure to meet the ice imaging experts Georgette Holmes and Steve Lilgreen. Georgette is a civilian and Steve is Navy. They’ve been sent on this cruise to provide satellite imaging and take photographs of any ice we might encounter so they can better correlate what they see in the images with what the ice is really like. Steve and I are both originally from Minnesota so I’ve enjoyed talking with him about the old country.

I tried to eat healthy tonight but the meals are just too good! I again ate too much and had two desserts so now I’m guilted into going down to the cardio room to pay my penance. I really don’t want to leave this ship ten pounds heavier than when I came aboard.

~John Petersen

Kate’s hydrophone was dry and she got her data! There is one problem though. The files are in a format that makes it very difficult to transfer and save data onto a new disc. The first ten thousand files are all named sequentially. The next seven thousand files after that are also named sequentially except the computer in the hydrophone did not include the ten thousands place in the name. So files numbered 10000 to 17000 have the same names as her first 7000 files. When she goes to copy the second set of files the computer asks if she wants to write over the first set. She’s devoted most of her day trying to come up with a method to some how saving all the data intact. She and David Mellinger, her partner in this project, are both smart people and I’m sure they will find a way to transfer all the data.

Last night we steamed into Barrow and picked up two Navy admirals along with some of their staff. They came out to observe a mooring recovery and to get a first hand feeling for how Arctic research is done and how the Coast Guard supports that research. They need this direct experience to help them make major funding decisions and give them the information they need to lobby Congress for more projects like this. They genuinely impressed me. They were very interested in the research and they asked good questions. I’m happy to know that my tax dollars are in the hands of competent people.
Bob and Harper gave talks to the Admirals and the rest of the science staff, which gave overviews of why they are doing the research and what they hope to learn from it. The main point I got from Bob’s talk was that storms over the Bearing Sea, that are centered 2000 km away, can reverse subsurface ocean currents and cause the upwelling of deep, warm seawater at more than 200 meters depth.

Harper’s talk centered more on research into how the ice on the surface can create open leads or pile together to make ice ridges in response to atmospheric storms. Harper’s and Bob’s research interests overlap except that Harper is looking at higher frequency responses and Bob is looking at lower frequency responses. This is why they have teamed up and placed their moorings, along with Tom Weingartner (UAF), to create a line from shallow near shore moorings to deeper moorings off the edge of the continental shelf.

About the time the science talk finished it was time for supper where I had a peach cobbler that couldn’t be beat. The cobbler had me obsessed for more sweets and then I realized that this was nature’s way of telling me to eat more to stay warm in the cool Arctic so I then had ice cream.

Recovering a mooring after supper was the big event of the evening. There was again some drama as the acoustic release did not want to respond at first. I’m not sure of the details but John Kemp, the chief mooring tech from WHOI, somehow got it to listen and release which then also released a lot of the tension that had been building for Bob. The Coast Guard crew in the small boat attached a line from the ship to the floats. The mooring crew performed their work almost like a dance and within a few minutes gear was on board.

The highlight was the recovery of an Arctic winch, which consists of a large buoy that contains enough batteries to run a winch on top. The winch raises and lowers a smaller buoy with instruments on top until it reaches the surface of the ocean or hits the bottom of the sea ice. Sampling the ocean near the ice has always been difficult with a conventional mooring because if it is placed too close to the surface, a large ice ridge might float by and rip off the top of the mooring. With the Arctic winch, data can be obtained below the ridge several times a day.

The weather was beautiful for watching a mooring recovery. The sky was blue and the sea was calm. It was a relaxing evening to stand out in the sunshine and watch the mooring crew work so hard.

Eventually, seeing the mooring crew work so hard made me feel like I should do some work too so I went to the cardio room to ride the stationary bike. While I was riding and watching the Terminator on TV the bike started rocking slowly to the right and then it would jolt to the left. It felt like a very slow but very major earthquake. On the way to the next string of CTD casts we ran into a large raft of drift ice. The ship would slide up on top of the ice and then crash down as the ice broke sending water and ice chunks splashing.

CTD rosette being deployed

Styrofoam cup shrunken by water pressure (see post from Monday 7/27/09)

Hydrophone mooring recovery

It’s been a Monday morning of mooring madness. This morning, Kate’s fourth mooring communicated just fine and told the technicians just where it was but it refused to release. This story has a happy ending and I’ll tell you how it ends after I tell about CTD casts.

I stayed up late last night to observe how the CTDs were done. A CTD is a Conductivity, Temperature and Depth measurement. A large rosette is lowered from the ship that has instruments that continuously measure the electrical conductivity, temperature and pressure. The rosette also has bottles that open up to collect samples of seawater at various depths.

The temperature is measured using a thermistor, a small electrical device that changes resistance as the temperature changes. The electrical conductivity is measured by determining how much electrical current flows between some platinum wires for a given voltage.

The pressure is used to determine the depth of the device. The greater the pressure is, the greater the depth. Just like when you dive to the bottom of a swimming pool the pressure on your ears will increase as you go deeper. In fact, the technicians who do the CTDs will sometimes attach Styrofoam coffee cups to the rosette. Under the great pressures of 1000 meters of depth (about 100 atmospheres of pressure) the tiny air bubbles in the foam will collapse leaving a miniature, shrunken cup.
The scientists aren’t really interested in the conductivity alone but along with the temperature they can calculate the salinity of the seawater. The more salt in the seawater the better it will conduct electricity. Also, the warmer the seawater the better it will conduct electricity. Seawater at the surface usually has a salinity of about 35 ppt, or parts per thousand. A salinity of 35ppt means there are 35 grams of salts dissolved in each kilogram of water. When sea ice freezes it ejects the salt into cracks and pore spaces making relatively pure ice and saltier water. Then when sea melts, because it is mostly pure water, local seawater salinity can decrease to about 25 ppt.

Knowing how salty the seawater is might be interesting if you need to sprinkle salt on your food but, again, most of the scientists want to know more. The next thing they start to calculate is the density of the seawater. The density depends upon the salinity and temperature. More salt and lower temperatures make more dense water.

The reason they want to know the density is so they can calculate if a water layer will sink or float on a layer of water below. Just like a raft that floats on water because it is less dense than the water, fresh water will float on salt water because it is less dense than the salt water. If you put ice cubes into a glass of salty water you can see a layer of fresh water forming on top of the salt water as the ice melts.
Occasionally, masses of less dense water will come in contact with more dense water and ocean currents will start to flow as the salty dense water slides under the fresher water. These currents can cause the remains of nutrient rich dead creatures at the bottom of the ocean to be brought up to the surface where they provide fertilizer to organisms that live near the surface. The organisms at the surface provide the food for the bigger creatures, such as salmon. Understanding ocean currents is critical to understanding weather and biological patterns. So, ultimately, understanding life as we know it on Earth depends on measuring the Conductivity, Temperature and Depth of seawater.

Now back to Kate’s mooring recovery. After trying to release her hydrophone several times, the technicians decided to try to drag for it. The ship did more CTD scans while the deck crew got set up for dragging. They eventually attached large hooks to some heavy weights and lowered them to the bottom while the ship crossed over the last known position of the mooring. Technicians closely monitored the tension in the cable as the ship milled about. If the tension were to shoot up dramatically it would indicate they had snagged something big and they would then have to reel in their catch. In this case, the drag hooks must have just shook the release enough that it finally let go and the floats popped up just behind the ship. After a several hours of carefully reeling in the drag lines and then sending a boat out to attach a line to the floats the techs got the gear on board. When I talked to Kate she couldn’t figure out why the release didn’t let go because it appeared to have clean release. But even more mysterious was the fact that two of the top four floats had been ripped off and the mooring had move 150 meters from where it was deployed last year. Obviously, something big came along and messed with her mooring and could this be the same thing that messed up her other moorings?

The next big question is did the seals hold out the seawater for the past year? She was anxiously waiting for the hydrophone to come up to temperature before she opened it to answer that question. She was afraid that if she opened it when it was cold, moisture would condense all over the electronics. I guess we will find out tomorrow if the seals held out the water and if she got good data.

~John Petersen

View the U.S.C.G.C. Healy latest ship track here: http://www.sailwx.info/shiptrack/shipposition.phtml?call=NEPP

This has not been a good day for Kate. I was supposed to video tape the recovery of three of her hydrophone moorings today and then help with the turn around to get them back in the water. Her moorings have been patiently recording the calls of marine mammals through out the past year. She can go through the recordings and get estimates of whale populations and migration routes.

Through no fault of the scientists or the technicians, not one of the three moorings was recovered. The first acoustic release was completely silent. It wouldn’t answer its wake up call. A technician will lower an acoustic transponder (microphone/speaker) over the side and then send coded pings to talk to the acoustic release. The acoustic release is attached to a heavy weight at the bottom of a mooring. When given the correct code, it will release the heavy weight and the floats at the top of the mooring will pull the scientific instruments to the surface. If an acoustic release is healthy and ready to release it will give fifteen pings as an answer to its wake up call. Mooring number two responded with seven which means it is laying on its side. Some how the floats at the top of the mooring flooded or came loose, which allowed the release to fall to the ocean floor in a horizontal position.

Mooring number three has caused the most mischief. It would ping back its location of say 1500 meters away. So the technicians would draw a 1500 m circle around the ship on a map. They then knew that the mooring was somewhere on that circle. Armed with this information they would move the ship to a new location where they would get another distance signal of say 1200 m. They would then draw a 1200 m circle around their new location on the map. The mooring should have been where the two circles intersect. At this point the ship would steam up to a third point to again start a conversation with the acoustic release. Unfortunately, mooring number three was playing a game of hide and seek so it would either remain silent or give a signal that said it had moved to a new location. The technicians and the ship played this game with the release all afternoon and were never able to get three distance readings in a row that made sense enough to accurately locate the mooring. If the mooring releases too far from the ship, the technicians run the risk of loosing it into some ice or maybe have it drift away in rough waters.

The rumor is that now the plan is to do CTD (conductivity, temperature and depth) measurements through the night and then try to recover a fourth hydrophone mooring tomorrow morning. After the recovery, we’ll steam back to Barrow to pick up some Navy Brass to observe the recovery of one of Bob Pickart’s moorings.

~John Petersen

A sense of excitement gripped me as the helicopter descended smoothly and gently placed me back on the deck of the Healy. I made it back for another cruise in the Arctic Ocean to recover the moorings that were deployed almost one year ago.

I’m John Petersen and I teach science and math at West Valley High School in Fairbanks, Alaska. Harper Simmons asked me to come back on this second recovery cruise with him aboard the U.S. Coast Guard Cutter Healy. We’re about ten miles north of Barrow, Alaska and we’ll be heading East into the Beaufort Sea.

The big questions for the next several days will be if we can find the instruments and if we do, are all the electronics still dry? It’s possible to lose instruments if there is ice cover to prevent the floats from reaching the surface and sometimes the acoustic releases don’t work. A piece of lint or any other minute speck of dust can cause a seal to leak. A slowly leaking seal can eventually let in enough corrosive seawater to completely ruin any electronics in the instrument making it worthless. To win in this game it requires careful and meticulous work and then a bit of luck. Harper and Mathew Alford provided the careful and meticulous work last year and now over the next two weeks we’ll find out if Neptune provided the luck.

My adventure began in the Fairbanks airport where I met Harper in the terminal. It didn’t take long before we were greeted by other scientists I met last year. Kate Stafford, an oceanographer/marine biologist, checked in after stopping off in Fairbanks to visit a friend on her way up from the Applied Physics lab at the University of Washington. She had deployed microphones under the ice to help with whale census surveys and to study migration patterns. Bob Pickart, the chief scientist on this cruise from Woods Hole Oceanographic Institute, also appeared at the gate.

After we arrived in Barrow and got settled into an old Quonset hut in what used to be called NARL, Navy Arctic Research Lab, and is now called BASC, Barrow Arctic Science Consortium, we all went out to dinner at a Thai restaurant and got reacquainted with people we knew from last year and acquainted with people that were new. The restaurant was small and the service was slow but the food was great. I don’t know what I ate because the waiter/cook served us family style. I just tried to eat some of everything he brought out. By the time I walked out of the warm restaurant and into the cool Barrow air I was stuffed and had four large cartons of left over noodles.

Harper Simmons

The next morning Harper and I ran the three miles along the coast into Browerville from BASC. The run into town seemed warm considering the temperature was only about 45 degrees and we had gray overcast skies. We made a quick pit stop into the Alaska Commercial Company store where the manager was thrilled to see some other runners. He had recently run a marathon in Florida and was training for another. He was so infectiously enthusiastic about running it was hard for us to leave and finish our run. The run back was considerably colder because we now had a strong head wind. To generate enough heat to keep me from freezing we did some sprints so by the time we got back to our Quonset hut I had broken into a good sweat. Harper was kind enough to cook breakfast. He served refried Thai noodles and coffee. I think they were better for breakfast than they were for supper.

A long hot shower put me in a mood for a nap, after which I had enough energy to make my way back to the A.C.C. store deli for lunch. I wanted to do some people watching as the locals stopped in to socialize. Besides, eating there is a lot cheaper than a sit down restaurant. While eating my lunch I started thinking about the ancient sod houses I had seen last year and I started to fantasize about finding artifacts. So with a full belly I walked into Barrow, past Arctic Pizza out across the tundra to the old village site. After poking around the numerous seal bones that had washed out of the cliff I saw a small speck of glimmering stainless steel. My heart stopped beating for a few seconds as I uncovered a Buck pocketknife that probably fell out of the pocket of some tourist as long ago as last week. It wasn’t exactly the stone age knife I was hoping to find, but I scored!

After my long day as an amateur archeologist I went out to eat with some of the others who were destined for the same cruise. Everyone else seemed intent on sushi. I felt like food that was cooked so I ordered a hamburger. My burger was good but not as good as the treat I had on the drive back to BASC. Kate Stafford’s super tuned whale watching eyes spotted a small bowhead whale only about 500 yards off shore. We watched it playfully splash around until we were just about frozen by the cold and damp ocean breeze that can easily cut right through most synthetic fabrics. Besides we had to get ready for the next day when we would helicopter out to the ship.

Since Harper cooked breakfast on Friday morning, I did the cooking on Saturday’s breakfast. I served refried Thai noodles. By 8:30 we had all of the luggage and people shuttled out to the Barrow Search and Rescue hanger. They were kind enough to put us up until the seventeen people going out to the Healy could get air lifted out two to four at a time. As the helicopter burned up more fuel weight the aircraft was able to carry more weight in people. I was about tenth on the list and had a pleasant wait watching cable TV and chatting with George Neakok. George was born and raised in Barrow and was on last year’s cruise. He is along to serve as a marine mammal observer and provide a cultural link to the Barrow community. While we were waiting George got a call from his wife. She told him that a polar bear had just walked by their house along the beach. I would have liked to run the couple of blocks from the airport to the beach to see it but I knew I should stay at my assigned post in front of the TV.

Overall the airlift went smoothly except for one 45 minute delay to wait for some fog to lift. While we were waiting I thought of Will Rogers and Wiley Post who crashed nearby and I was thankful for a cautious pilot. Now that I’m safely on board and in my room writing this, the weather has cleared up completely. I think its time to dig out some sunscreen and go out on deck to enjoy the Arctic scenery.

~ John Petersen

Welcome to the first blog entry for our 2009 mooring recovery cruise on board the USCGC Healy.

Tonight cruise participants will be at BASC in Barrow, Alaska.

We are scheduled for helicopter transport to the Healy on Saturday the 25th.

Barrow weather is typical (from the National Weather Service):

“TODAY…MOSTLY CLOUDY WITH AREAS OF FOG. HIGHS 40 TO 45. NORTHEAST WINDS AROUND 15 MPH. TONIGHT…NE WINDS 20 KT. SEAS 4 FT. FOG.”

Ice has been held offshore as you can see from the Barrow Sea Ice webcam and the most recent ice maps.

With the steady winds and open water, it looks like we can look forward to some chop.