Don's Log

   19 August - 31 August: Towards a Rendezvous with the Oden

Friday 19 August
Aboard Healy Northbound in the Arctic Ocean
78 50.571 N, 176 23.568 W
We arrived at the coring station a little early and had our boat briefing at 2115. There are a number of interesting floes in the neighborhood, but they are all kind of small, 100 m or less. I picked one of the bigger floes; it was a nice mixture of white ice and blue ponds. The floe looked much bigger from the bridge. Down on the surface it was only 85 m long and 20 m across with two big melt ponds. For a small floe there was considerable complexity, with thin ice and ponds surrounded by hummocks. There was also an area with a highly developed surface scattering layer that was 8-12 cm deep. Jeremy has a nice map of the floe. There is also a panorama from the rail plus plenty of photos on the ice, not to mention countless photos taken on the ice.

I did the standard thickness survey with the EM-31. Since the floe was so small I basically walked back and forth as though I was mowing my lawn getting a total path length of 600 m. The statistics of the floe thickness should be good, but my course was a little too meandering to generate a two-dimensional map of the floe thickness. The average thickness was 136 cm, with thicknesses ranging from 50 to 220 cm. The melt ponds were connected to the ocean and had a salinity of 29 ppt and a temperature of -1.5 C. There was undercutting of the ice around the edge of ponds by 24 to 75 cm. The floe edges were undercut by more than a meter at some locations.

After a semi-late night, it was time to catch up on data. After the morning flight briefing we all started working to archive the data from last night. I have a great memory, for one day. I need to archive one day’s activities before starting the next or it all blurs together. Was yesterday the day the sun appeared, or was it the day before? Was the first ice core from the melt pond, or from the bare ice? You get the idea. (The first core was the bare ice). People have likened field work to the movie Groundhog Day. You’re in a groove, working hard and enjoying it, but there is a certain general sameness to the days.

Speaking of sameness, Bruce and I continued the afternoon optical measurements. We made a set of spectral incident measurements followed by an hour of minute by minute reflectance measurements from the flying bridge. The measurements are valuable, but perhaps more valuable is observing the ice and noting its changes. Today the ice surface seemed just a little brighter. A few ponds had a skim of new ice on their surface and there were patches of nilas in some of the leads.

As the photographs show, there was an interesting appearance this afternoon. If there is one thing that gets everyone’s attention it’s a polar bear. This was a big, healthy looking bear that ambled along by the ship for about 10 minutes jumping from floe to floe. I took about 30 digital photographs and none of them were very good. My telephoto is buried with our gear. Luckily one of science party, aptly enough Bjorn, took some beautiful photos and shared them with everyone.

The Captain gave a great lecture this evening on icebreaking. He talked about the capabilities of the Healy and the keys to effective icebreaking. The one thing to remember above everything else is “Keep your rudder amidships when backing.”

1. What can get everyone on the bow of a ship?

2. A polar bear (photo courtesy of Bjorn)

Saturday 20 August
Aboard Healy Northbound in the Arctic Ocean
79 35.6132 N, 172 26.7023 W
Today we are scheduled to arrive at Coring Station 6. It could be a busy day as we hope to do a thickness survey, take an ice core, make some optical measurements, and if the ice looks good maybe install an Ice Mass Balance Buoy. And, of course, weather permitting, do a helo photo survey. But before all that, it’s Saturday morning and time to clean. Bruce and Jeremy take out the trash from the Science Lounge, while Tom and I vacuum.

I was called to the Aloft Con at 1100 to look for good floes. It’s a beautiful day in the Arctic; the fog has lifted and the ceiling is about 1500 feet. The temperature is just below freezing and the wind is very light. The ice cover is mix of a lot of sorry looking ice that is less than a meter thick and some healthier looking floes. There has been considerable discussion about whether the sorry ice is first year, second year, or just thin multiyear. In any case it’s too thin for a buoy. There is a nice piece of multi-year with a white surface and the beautiful blue ponds that mean it’s over a meter thick. After an excellent maneuvering effort we are parked with port adjacent to the floe. Really excellent ship handling.

Unfortunately the edge of the floe is irregular and rotted and there isn’t a good place to lower the basket. Also, unfortunately, while the pack is loose there is little open water and with a lot of brash and small floes the boat can’t be launched. And finally flight operations have been cancelled. So here we are, all dressed up, with nowhere to go. Its definitely a case of look, but don’t touch. But you can always learn about the ice just by looking. So we take photos instead of samples to characterize the surface. Our local ice neighborhood consists of a 100 m x 50 m floe off the bow that is a large pressure ridge surrounded by rubble. The ridge is about 2 to 3 meters tall and is probably 6 to 8 meters deep for a total thickness of 10 m. Right next to it is some of the “sorry looking ice” (this is not an official ice term) that is about half a meter thick. This is typical of the tremendous variability of the ice cover. This spatial variability makes it fascinating to study and difficult to understand.

Figure 1. Pressure ridge with a 2-3 meter sail (height above the surface).

Figure 2. “Sorry looking ice”; Thin, gray ice that is about 0.5 m thick.

Sunday 21 August
Aboard Healy Northbound in the Arctic Ocean
80 04.875 N, 173 22.343 W
Sundays often start out slow, particularly after a big station on Saturday. Sunday breakfast is from 7 to 9 followed by brunch from 10 to 12. We will be in transit to Station 7 all day and no flight operations are scheduled. This means an easy morning and optical measurements in the afternoon. An easy morning consists of laundry and a workout in the gym. One big load of laundry and an hour on the bike.

The weather feels late November back home in New Hampshire. Its snowing, but in a wet sputtering sort of way. The ponds and the smaller leads are beginning to freeze over, but only a little. The smaller leads have a couple of centimeters of slushy sea ice called nilas (see photo). This ice is mushy and bendable. The wind can push one layer of nilas on top on another, rafting the ice and doubling its thickness. You definitely do not want to try to walk on this.

Bruce and I made incident irradiance spectral measurements and reflectance measurements from the rail. We measured from 1415 to 1520 ADT with the instrument and computer covered by plastic bags. The instrument works fine in the cold, but not so well in the wet. In general the reflectance from the ice was higher today. Why? The ice had a 1 centimeter layer of snow on it, enough to increase the amount of light reflected.

One of the goals of our program is to understand the partitioning of solar radiation by the ice cover. Or more simply to answer the question: where does all the sunshine go? Sunlight can either be reflected by the ice cover, absorbed in the snow and ice, or transmitted to the ocean. A key element in this question is how much light is there to start with – what is the incident solar irradiance. We have been measuring the incident solar spectral irradiance every afternoon. As the plot demonstrates the spectral incident shows a peak in the visible part of spectrum and is lower at longer wavelengths. The x-axis of the plot shows wavelength. For reference, visible light is from about 400 nanometers (blue) to about 750 (red). A nanometer is one billionth of a meter – this is very, very, very small. The dips in the spectrum are wavelengths that are strongly absorbed in the atmosphere. If we measured the incident sunlight in outer space, the values would be larger and the curve would be smoother.

Later this afternoon, we crossed the 80th parallel. It was just a coincidence, but just then it started to snow for real.

Figure 1. Nilas ice forming in a lead. Leads are areas of open water.

Figure 2. Plot of the incident spectral solar irradiance. This is the amount of sunlight reaching the surface as a function of the wavelength of the light.

Monday 22 August
Aboard Healy Northbound in the Arctic Ocean
81 13.4809 N, 177 11.5813 W
Each morning, on the way to breakfast, I look outside just to check the weather. Today I saw a most unusual sight – the sky. Not all of it, mind you, but a small sliver across the horizon. It looks promising for a photo flight. Sure enough there is a flight brief on the bridge and we are good to go for a photo survey flight. Even better after the survey flight is to do a “hot deck refuel” and then do a second flight where we can install our buoy. The weather holds and Jeremy gets his first complete helo survey flight. They fly our standard 80 nm box (10 east, 10 north, 20 west, 20 south, 10 east, 10 north to the ship) at an altitude of 1000 feet. We cranked up the sampling rate to a photo every 3 seconds so that we can mosaic a strip 130 km long and 300 m wide. It did take 1000 photos to do it, but that’s only 3.3 GB, less than a DVD.

After the helo flight is completed, Jeremy and the camera pod get off, and Bruce and I and the buoy on. Before flying, the pilots asked us about the weight of our gear. I estimated the weight at 250 pounds. Everything was weighed so that the fuel could be calculated. It weighed exactly 250 pounds. Boy, am I good. Scientists are notorious for lowballing estimates. 100 pounds is more like 200 and an hour is often three.
After takeoff we quickly found a good floe to install the buoy. There were numerous good choices. Our pick was a few hundred meters across. There was a substantial ridge on one end (Figure 1) and a few melt ponds. The ridge portion was very thick, but at the buoy location the ice was 1.4 m thick. We got everything installed and did a quick melt pond survey in less than an hour. The local ponds were 28 cm deep, with 2 cm of new, clear, fresh ice on the surface. We lifted off, took a few aerial photos of the site, and had an excellent flight back to the ship, as there were lots of interesting melt ponds to photograph. My new digital camera is great. Of course I am totally out of control taking 100 photos just of the site and the flight back. Somehow I don’t think I would have taken 4 rolls of film using my old camera. The helicopter is definitely the way to install these buoys. It’s quick, easy, and there is a wide choice of floes.

So what exactly is an ice mass balance buoy? It’s a field experiment in a box. The ice mass balance is a simple concept. It is the amount of ice growth and melt and the snow accumulation and melt. A few of us at CRREL developed an autonomous buoy to measure this. There are four pieces. The brain resides in an 8 inch steel tube and consists of a datalogger, multiplexer board, and a satellite transmitter. There is a string of temperature sensors placed every 10 cm that extends from the air through the snow and the ice into the ocean. There are also two acoustic sensors; one monitors the position of the surface and the other the position of the ice bottom. The data are transmitted from the buoy to our office by satellite. When you put it all together it’s the ice mass balance. Figure 2 gives an example of results from one of our buoys. For more information check our web site at http://www.crrel.usace.army.mil/sid/IMB/index.htm.

Figure 1. Photograph of ice mass balance buoy site 1.

Figure 2. Sample results from an ice mass balance buoy. The middle panel represents the snow and ice. Gray is the snow and dark blue is the ocean. The colorful contours show the temperatures in the ice. Blue is cold and red is warm.

Tuesday 23 August
Aboard Healy Northbound in the Arctic Ocean
82 22.891 N, 178 48.804 W
We got out on the ice last night for Ice Site 4. Everything went really well and we got a full suite of measurements done in one and a half hours on the ice. The measurements included an ice core, two light transmission sites (bare ice and melt pond), a 1.1 km ice thickness survey, soot samples, melt pond thickness, temperature, and salinity measurement, and a profile of a lead. The average ice thickness on the floe was 1.4 m and the ponds were about 30 to 40 cm deep. We also made some measurements in the lead. You have to be a little careful when approaching the edge of a floe because often the ice is undercut by wave action. It looks like thick ice, but is only a few cm thick. Maybe enough to support your weight, maybe not. Usually I stop a meter away from the edge and lie down to take a look. This spreads your weight out so you are less likely to break the ice. The edge was worth studying as was undercut by about half a meter. We also measured the salinity of the top meter of the lead. The salinity of the very top of the water was only 18 parts per thousand compared to 29 deeper down. This is because fresh water is less dense than sea water. With all the ice melt occurring, fresh water runs into the leads and if it isn’t windy tends to stay on top. All in all, Monday was an incredible data day.

This morning was not quite as nice as yesterday, but still good enough for flying. The helo plan is to do a photo survey flight first with Jeremy operating the camera, followed by Bruce and me on an on-ice measurement flight. The helo is rolled out, the camera pod is mounted, and the fog rolls in and the snow starts and the flight is cancelled. So instead of flying, we work on data reduction and backup.

By afternoon it was snowing fairly heavily and the wind had picked up to 15 miles per hour. The snow was wet with large flakes and temperatures were right around the freezing point. It was snowing hard enough that we had to wrap the spectroradiometer and the computer in garbage bags to make sure that didn’t get wet. We are monitoring the ice cover by a wide variety of observations with an assortment of instruments. However, we can also feel a very noticeable change that has occurred the past day. More bangs and bumps and grinding noises on the hull tell us that icebreaking has gotten a bit tougher. We are still making excellent progress, but we are encountering thicker ice and more ridges.

Figure 1. A photo of Site 4 with our measurement locations.

Figure 2. Healy 1, the zodiac that transports us to the ice.

Figure 3. Bruce and Jeremy messing around in a pond.

Wednesday 24 August
Aboard Healy Northbound in the Arctic Ocean
82 59.375 N, 177 41.812 W
The plan was the same as yesterday. A morning helo survey flight followed by a helo flight for on-ice observations – weather permitting. That of course is a big if. Today is a good example. It’s trying to be nice. Occasionally you can even see some blue sky and the sun, but the fog continually comes and goes. After waiting all morning for the weather to improve, science flights are cancelled for the day.

It was the usual shipboard afternoon optics measurements – spectral incidence followed by a spectral reflectance survey. Conditions were sunnier than usual, enough so that we needed to worry about shadows when taking the measurements.

Tag team science talk this evening about the Swedish Beringa 2005 field experiment and about the deep coring down in the Arctic last year. The coring experiment had 3 icebreakers; one doing the coring and the other two upstream of it smashing the ice. There was a good video of the experiment. For more information about the Beringa experiment check out this web site: www.polar.se/beringia2005

Time to go to bed early tonight. Conditions permitting, tomorrow may be very busy.

Figure 1. An unusual sight in the Arctic Ocean in summer: blue sky.

Figure 2. The melt ponds are freezing with interesting patterns of frazil ice and snow ice.

Thursday 25 August
Aboard Healy Northeast bound in the Arctic Ocean
83 10.9421 N, 174 04.9479 W
Its time for Buoy-O-Rama! The plan (hope?) is to install 10 buoys today while we are stopped at Coring Station 8. I’m up early at 0600 and head up to the bridge to see what is happening. The maneuvering for Station 8 has just ended and there is a nice floe portside with easy access from the basket. The floe has a nice central region about 25 x 50 m that is pond free. Getting there might be a little tricky. There is the direct way that entails crossing only one narrow (2 m) crossing of a network of melt ponds. There is also the circuitous no pond way that is about 300 m long rather than 100m. Not only that, the weather seems to be decent. Not great, but possibly good enough to deploy the deformation buoy array. There is time for a quick breakfast (scrambled eggs to go with the usual cereal) and off to the 0730 flight brief. The weather is good enough to try.

Meanwhile Bruce and Jeremy are lugging the 6 “tubs of fun” from the bow to the helo deck. Each deformation buoy is a yellow tub with a global position sensor, a satellite transmitter, and a lot of batteries. The batteries make them a heavy and awkward 90 pounds a piece. The plan is to take three, install them, return to the ship, hot gas, pick up the other three, install them and return. The buoys will be placed in a hexagonal array with the ship in the center, each buoy 10 nm away placed at bearings of 0, 60, 120, 180, 240, and 300 degrees. Installation is straightforward, pick a good floe, land on the ice, drag the buoy away from the helo, drill a hole to anchor the buoy, lift off, and repeat 5 times. The flight crew and Ruben, a high school teacher from Sweden, will have the challenge of making it all happen.

The weather isn’t great, but its workable. The visibility would be insufficient for a helo survey flight, but it is enough to install the buoys. It’s relatively warm, just about freezing, but its windy averaging 15 knots, with gusts up to 25 knots. There is some light precipitation that is a mix of snow and sleet. The ice has firmed up considerably from just a few days ago. Most of the bare ice has a hard firm surface. Unlike the ponds, which are covered with soft mushy ice a few cm thick. Freeze up is coming, but slowly. With the ponds freezing and leads freezing and a patchy dusting of snow the albedo has increased noticeably.

Meanwhile on the adjacent floe there are four buoys to install. The second of the CRREL ice mass balance buoys, a PMEL web cam, a JAMSTEC meteorological buoy, and a JAMSTEC ocean profiling buoy. Total weight of all the equipment is about 1000 pounds. And of course we also want to do all the usual thickness surveying, ice coring, optics, surface characterization, etc. The helo lifts off at 0830 streaking north. By 0850 the deck is cleared and the basket is ready. So what is “the basket”? It’s a metal frame attached to the crane. A couple of people plus their gear can easily fit in. It’s a very smooth ride to the surface. The first trip is the bear guard, me, and a sled load of coring equipment. I’m off to check out the shortcut. The edges break off making the pond 3 m across and it’s about 50 cm deep. Not too bad for one person to traverse, but not a route for 9 people and half a ton of gear. It’s the long way, which also has a few pitfalls. Good word pitfalls. There are some small ponds that have partially frozen and drifted over with snow. The pond ice is strong enough to hold the snow, but not us. There are lots of deep boot prints full of water. There are two ways to avoid falling in. One is to let somebody else go first and make all the mistakes. The second is to look very carefully and try to avoid the places that look just a bit whiter than the surroundings. With no one to follow, I look and do pretty well, only breaking through twice. No problem, since the water wasn’t higher than the top of my boot.

Our best auger the “Finn-Bore” is on the helo to be used for installing the deformation buoys. Second choice is the 2-inch auger. This does not drill anywhere near as well. Drilling became difficult only 30 cm into the ice, when the auger started to get stuck a little. When this happens you just add more muscle. Unfortunately when I added more muscle I sheared the handle off the drill. Plan B is to hook the drill up to the motor, which works fine, for a while. We get all the holes drilled and the buoy installed in about one hour and fifteen minutes, and includes the time it took to drag the sleds. Not too bad.

The web cam is next on our installation list. This is very easy to install; drill one 10 inch diameter hole down about 3 feet, insert buoy tube, and hook camera onto buoy tube. We get stuck on step 1 when the gear box on our power head breaks. The engine runs, but the auger doesn’t spin. That’s ok because we have a backup. Our general policy to have a backup for everything. Things tend to break in the Arctic and stores are hard to come by. There are a few big ticket items like our electromagnetic thickness device ($25,000), but everything else has at least one spare.

After the buoy installation I do a thickness survey collecting a total of 450 points and covering 2.2 km of transect. I did some serious meandering, not crossing my path but wandering back and forth. The mean ice thickness was 2.10 m and the median was 1.8. The ice thickness ranged from 1 to 7 m. This represents the thickness of the unponded ice. The ponds are two sketchy to be walking in with an expensive instrument as a shoulder bag. Bruce and Jeremy were drilling ponds to get their ice thickness as well. Tom, Jeremy, and Ute were doing light transmission measurements. The first site they selected was too thin, with a pond ice thickness of 25 cm. So they looked for thicker ice and found it in 2.5-m-thick bare ice. We retrieved cores from the bare ice and the adjacent pond.

Everything was completed by 14:20 and the basket retrieved us from the ice. All four buoys were installed at this floe and all six buoys of the deformation array were deployed. Pretty good for a day’s work. We worked through lunch so I brought out a bag of Chips Ahoy sandwich cookies, which four of us finished in 5 minutes. They’re pretty good – chocolate chip cookies with icing in between. They will also serve as my birthday cake, since today is my birthday. They say you only turn 30 once and I did five squared years ago.

Figure 1. Bruce and Ute on the ice, with Healy in the background. Ute is a high school teacher in Brownsville Texas.

Figure 2. CRREL Ice Mass Balance Buoy plus "friend."

Figure 3. Diagram summarizing Buoy 2 site.

Friday 26 August
Aboard Healy Northeast bound in the Arctic Ocean
83 26.992811 N, 172 22.41108 W
The morning weather was the usual low ceiling so a photo flight was not possible. But today is set to be a doubleheader, two sites in one day. Right after breakfast we are ready to start Ice Site 6 at Coring Station 8b. Today we have a new means of transportation to the bridge – the brow. The brow is basically a long gangway that is held in place with a crane and goes from the bow of the bridge to the ice. It is a very convenient way to get on and off the ice. The only drawback is that is rather steep, around 45 degrees. You definitely do not want to be carrying equipment in your arms as you go up and down.

We spend a busy morning from 0930 to 1100 on the ice. Our floe was bigger than the earlier ones. In fact the floes have been getting bigger the past few days. I did an ice thickness survey, as always meandering around floe trying to avoid the ponds. Most of the floe was similar to what we have been measuring before. However, there was a section on one edge that was distinctly different; much thicker and with bluer ponds. The way I’ve been surveying does a good job of examining the unponded ice only. Ideally I would also survey the ponds. Practically speaking that would be a risky business. Many of the ponds have slippery bottoms. One misstep and the EM-31 would be underwater, which is not its preferred habitat. Even worse, a few ponds are “black holes”. These are ponds that either have no bottom, or a very thin bottom. A few centimeters of ice over 2300 m of water is not a good combination. We include the ponds by drilling them individually and measuring the water depth and the underlying ice thickness. We also do light transmission profiles, take an ice core, take snow and ice samples for soot, and characterize the surface layer. Not bad for 90 minutes.

The second site was “Ice Liberty” - two hours (1500 to 1700). Everyone was looking forward to the opportunity to study the morphological properties of the ice. Or maybe it was the chance to have a couple of beers. Chilling the beer was not a problem. People were in high spirits, even before the alcohol kicked in. After three weeks of hard work, it’s a great chance for people to get on the ice and relax. I made a quick thickness survey and goofed off the rest of the time. I got to use my sea ice morphology skills to retrieve a soccer ball from a melt pond after a couple people had gotten wet trying. You have to know where to step. There was a full scale international soccer game going on. I passed, but hit some golf balls with Dennis. He had a right handed 9 iron, which I had to invert to use. Surprisingly I hit the ball pretty straight. Maybe the key is to play in a parka to help control the swing plane. Then a few of us introduced some of the Swedish contingent to American football. It was an interesting way to play catch. The US would throw the ball and Sweden would accurately kick it back. Passing was interesting with an icy ball and tricky winds. The deep routes were really tough. Like playing in Buffalo in December.

Dinner was lively and festive, with everybody feeling great. I spent the evening trying, but not quite succeeding to get caught up with data.

Figure 1. Ice liberty - football, soccer, golf, and relaxation. The UV index was 1.

Figure 2. Captain Oliver of the USCG Icebreaker Healy plus some broken ice.

Figure 3. Chief Scientist Dennis Darby goes for the pin on 18.

Saturday 27 August
Aboard Healy Eastbound in the Arctic Ocean
84 11.485 N, 164 5.913 W
The routine is exactly that, a routine. Wake up, eat my Flintstone chewable vitamin, get out of bed, get dressed, go to breakfast, with a stop for a weather check. Skies look reasonable today for a photo flight. It would be nice since its been a few days since we had one. After breakfast, things happen fast. There is a helo briefing at 0830. Not only is the helo flight on, but they are going to put down the brow off the bow (try to say that fast five times), so we can do an ice site. Jeremy has the honors for the helo survey flight. The ice party consists of a bear guard, Tom, Bruce, Ruben, and me.

This was an old multiyear floe. There were a couple of flat areas, but much of the floe was hummocks and old weathered ridges. You got the sense that this floe had seen a lot of dynamics over the years. There was quite a bit of surface topography, though with the flat light and dusting of snow, I tended to trip over the bumps before I saw them. Snow depths ranged from 0 to 15 cm. Most of the floe had less than 2 cm of snow, but there were a few deep areas at the edges of ponds and on the lee sides of ridges. While I was doing the thickness survey, Bruce and Ruben were taking a core and Tom was preparing for a bare ice set of transmission measurements. Before leaving, Tom also took some soot samples and did a surface characterization.

Jeremy made it back in time to join us on the ice. With a few changes to the pattern, the flight was completed albeit at a low elevation of about 450 to 500 feet. The pod camera worked fine and we have another 1000 images to analyze.

After lunch, Bruce and I do “afternoon optics on the rail”. It sounds like the title of a radio talk show. It’s completely overcast, but the sun is occasionally visible. During the hour we do measurements, the ship has to back and ram twice to break through ridges. One ridge was big, with a sail over 2 m tall.

Icebreaking has gotten more difficult the past two days. Most of the time we still are making excellent progress, moving at 3 to 4 knots. However, there are more big ridges that require multiple backing and ramming runs. The ice is changing also. The ponds are freezing, snow is covering more and more of the surface, and the ice surface is getting cold. Drilling holes and taking ice cores has gotten noticeably more difficult the past couple of weeks.

Figure 1. Ruben, a high school teacher from Sweden, drilling a core.

Figure 2. Photograph of ice core taken by Ruben. The top of the core looks white because there are a lot of air bubbles.

Sunday 28 August
Aboard Healy Eastbound in the Arctic Ocean
84 12.771N, 154 35.79 W
I woke up at 0600 and the ship was motionless. That probably means we are on station and that I need to go up to the bridge and find out what is happening. It turns out that we are on station and are scheduled to get out on the ice at 0830. We pack up and take everything to the helo deck since the basket is today’s mode of transportation to the surface. There is a slight delay as we wait for the sediment core to make it to the surface, but we are on the ice at 0940.

The early morning snow has ended and the skies have cleared enough that the sun is visible. There are even shadows on the surface. It’s a beautiful morning. With the sunlight the topography of the floe is clearly visible. It is an old multiyear floe that with lots of ridges and ponds. There is enough new snow that Bruce does a 100 point snow survey, while I am doing a thickness survey. We also perform a calibration of the EM-31 measuring the same site with the instrument at different heights. Tom and Jeremy do two sets of light transmission measurements – bare and ponded ice. And for the first time this trip we walk on a melt pond. The refrozen ponds are just on the edge of walkable. It would take very little effort to break through, but if you are careful and shuffle slowly you can stay on the surface. However, the ice does bend and there are these unnerving little cracking noises. The optics pond had 4 layers: a couple cm of snow, 7 cm of ice, 30 cm of pond water, and 60 cm ice below. We are back on board in time for Sunday lunch, hamburgers, always a big favorite.

In the afternoon, the four of us got together to work on data. The past few days have been very busy and we have gotten behind in our archiving. Then, as always, in was optics in the afternoon. The evening got interesting when we encountered a huge dirty ice floe. The ship stopped and Dennis and Martin went out to get some samples. The floe looked very strange. It was quite dirty in appearance and there has been rafting of the floe. There were also some odd looking features that were probably a result of differential surface melting due to the sediment.

Figure 1. Site 9 with snow-covered melt ponds, ridges, and some sun peaking through the clouds.

Figure 2. The basket, one of the ways we get on the ice.

Figure 3. Dirty ice floe. In the fog it had a surreal appearance.

Monday 29 August
Aboard Healy Eastbound in the Arctic Ocean
84 18.773N, 149 03.821 W
The day started out pretty slow, but that would all change. The schedule was to arrive at Coring Station 9 in the early evening, right after dinner. So we spent a leisurely morning get caught up on yesterday’s data. I was near the front of the line when lunch opened at 1100. I did make two trips to the pasta bar, but I resisted the mozzarella sticks.

The 1300 flight brief was cancelled due to the usual weather; low ceiling with intermittent snow and sleet. It looked like an afternoon of optics at the rail, when at 1330 the ship stopped. Surprise we are at coring station 9a. No problem since we had gotten all of our gear ready in the morning. As always the first question is how will we get on the ice. The basket is not an option since its landing zone is a lead. The bow brow is a possibility, but it will be tricky, because of a big melt pond. Luckily the brow just missed the pond, as long as you swung to the right as you stepped on the ice. In addition to the ice squad and bear guard, we had some guests today; my roommate Howie, Asa the reporter from SPR (Swedish Public Radio), Eva from the Swedish Polar Secretariat, and Kazu from Hokkaido. It was one thick floe, most of the drill holes were 3 m thick.

There was more snow on the ice today. That seems to be a trend. Each day a little more snow. Typically when I go up to the bridge in the morning there are a couple of centimeters of snow on the deck. Day after day this adds up on the ice. Late August through October is the period of greatest snow accumulation on the ice. The atmosphere is cooling and the moisture is being squeezed out as snow. It seemed a little warmer than yesterday. The snow was good for snowballs and there was intermittent snow/sleet. The air temperature has been flirting with the freezing point for the past few days. It varies from just over freezing to a few degrees under.

It was a new floe, but the same old plan; ice thickness, snow depth, pond properties, optics, soot samples, and ice cores. This was probably the thickest floe we have encountered. More of the holes we drilled showed thicknesses over 3 m and there were large ridges all around. The optics melt pond site was 2 m thick! With 8 of us working we completed all of our measurements and were back on board at 1615, just as the seafloor multi-core was finishing.

After dinner it was time for some Christmas shopping at the Healy exchange. I bought an assortment of t-shirts, sweatshirts, patches, and coffee mugs for everyone in the family. The evening plan was to do the 1800 ice watch and then hit the gym. But a patch of dirty ice was spotted so a field trip was quickly organized. 6 of us went out to sample dirty ice. Bruce and I took a core and the rest of the group chopped pieces with ice axes. The weather was actually pretty nice and the whole endeavor only took about an hour.

Figure 1. Spectral albedo measurements of a melt pond at Site 10.

Figure 2. A dirty ice block at Site 11.

Figure 3. A sculpture of ice. The southward facing side of the block had more melting due to sunlight.

Tuesday 30 August
Aboard Healy Westbound in the Arctic Ocean
84 18.773N, 149 03.821 W
Today is scheduled to be déjà vu all over again. The plan is the same as yesterday. A helo survey flight if possible and a station in the afternoon. The usual morning snow and reduced visibility preclude a photo flight so I start working on organizing data. As I work through the data I hear “Flight briefing on the bridge in 10 minutes. Looking out the window, the weather isn’t bad, but the ceiling is fairly low. Up on the bridge I learn that the flight will not be for photography, but to try to get some dirty ice samples. Dennis is going and Bruce will go to assist and possibly take a core. The good news was they found a floe that was incredibly dirty. The bad news was that when they tried to land the skis on the helicopter started to sink in. The floe was just too weak. They did make a very brief stop on a floe that wasn’t quite so dirty and got a couple of samples. It wasn’t dirty enough to make coring worthwhile.

We have entered the realm of dirty ice. It is ubiquitous. There are sections of dirty ice everywhere. Highlights included a dirty section on today’s floe that had mud and bits of grass. At the 1000 ice watch Takashi saw a tree trunk on the ice.

Shortly after lunch (sandwich bar, a personal favorite) we were on station. It was a perfect parking job for the ship. The starboard stern was in open water and the port bow was up against a nice floe. The sediment core goes down to the bottom of the ocean and we go down the brow to the ice. Today’s site was a large floe that was thinner and less ridged than yesterday’s. There is a bit more snow than yesterday. It is still very fluffy and when you walk you sink right down to the ice surface. All the ponds are refrozen and many you can walk on. The question of course is which ones.

We are on the ice from 1320 to 1540 doing our usual assortment of observations. I get a nice long, meandering walk with the EM-31 collecting 427 points. As always I tried to avoid the melt ponds, but it is getting more difficult and I unwittingly crossed a couple. The ice held, but I could hear it cracking. Eva did a 100 point snow survey for us along the beginning of the EM-31 track. Bruce was recruited to lead a dirty ice expedition to the far end of the floe. They hit paydirt both literally and figuratively finding mud and grass. Kazu took an ice core from under his instrument. Tom and Jeremy did the usual double optics site. When that was completed Tom took soot samples and Jeremy drilled some melt ponds. It was a busy and productive stop.

While every day is different there is a certain routine to our measurements. There is also a routine to the weather. The temperatures have been in the 20's, with an inch of snow every “night”. The sun doesn’t set this time of year, but it is higher in the sky at noon and lower at midnight. We pretty much have the same daily weather cycle. It’s snowing at breakfast, clearing by lunch, fairly nice in the afternoon through dinner, increasing fog in the evening, followed by snow. There are the occasional breaks in the fog or the oft present low stratus. We usually see the sun, sort of through the clouds, every day, but blue sky is pretty rare.

We spent the past day and a half going east. After the station we turned around and headed west, retracing our steps. The Oden has been delayed by heavy ice and is now going to the northwest. We are basically shadowing them to the north. They are approximately 120 nm miles away. In good ice conditions that is about a day. In heavier ice it could take a few days.

Figure 1. Eva measuring ice thickness using the EM-31.

Figure 2. Bruce taking a core.

Figure 3. Jeremy measuring thickness.

Wednesday 31 August
Aboard Healy on station in the Arctic Ocean
84 10.249N, 150 59.71 W
Once again I awaken to quiet, which means we are stopped and there is a chance to get out on the ice. So it’s out of bed and up to the bridge. Great news, not only are we up against a very nice floe, but the weather looks reasonable for flying. By the 0830 flight brief the weather has improved even more. The flight is scheduled for joint science photo and ice recon. Rather than our regular box the pattern will be out 50 miles over a few miles and back 50 miles. It’s a different pattern, but still gives us a good sample. Jeremy is all set and ready to go. Of course the visibility begins to deteriorate just as the helo is taking off. They only get a brief 15 minutes at elevations ranging from 500 to 1000 feet.

There was a slight delay in getting on the ice as a bit of fine tuning was needed to position the basket for site 13. Six of us are on the ice at 1040; Mike the bear guard, Emma a sediment core researcher, and the four of us. For a change of pace, I do some spectral albedos first at Tom’s snow covered ice and melt pond sites. The sky conditions are complete overcast with the solar disk visible and light snowfall. First I take incident scans for our incident spectral irradiance observations, and then measure the albedos of Tom’s refrozen melt pond, snow-covered ice, and another pond that was slightly darker. For a point of comparison with the rail observations I use the bare fiber to measure reflectance at 45 degrees for snow covered ice. This will enable us to calibrate the white reference standard. Optics is done so I put the $60,000 instrument into a 50 cent garbage bag to protect it from the snow and move on to a snow/ice thickness survey.

While I was doing optics Bruce and Jeremy finished the core holes for Tom’s transmission measurements. There is enough snow now that we want to measure it in conjunction with the EM-31 observations. The snow is fluffy so we really don’t need to correct for it, but we do want to correlate ice thickness and snow depth. Since we have an extra person, three of us set out. Bruce measured the snow depth, Emma wrote the numbers down, and I did the EM-31. As I mentioned yesterday most of the ponds are frozen, but not all. We successfully navigate a few, but Bruce breaks through one. Luckily it had an ice bottom, so he only fell into 30 cm of water rather than 2300 meters. Jeremy drilled some of the melt ponds. A typical pond was an ice sandwich; 12 cm of ice on top, 25 cm of melt water, and 65 cm of ice below. We got a nice set of data, but at a significant sacrifice. We missed lunch and it was grilled cheese day, one of my all-time favorites.

Shortly after we returned from the ice it was “Set flight quarters to condition 1.” It was the arrival of the helicopter from the Oden. They are about 45 miles to the south of us. A few people from the Oden came to begin discussions about the plan for the next few weeks. There was a science meeting for about an hour followed by dinner. We are entering a portion of the Arctic where the seafloor is very interesting and so the plans are very ambitious. At present the estimated time of arrival at the North Pole is September 10.

After dinner we moved slightly to an adjacent floe for a dirty ice hunt. Bruce and I did a quick snow depth and EM-31 thickness survey. The floe had considerable topography with rolling hills of hummocks and several ridges. The snow was still light and fluffy and there was drifting.

Figure 1. Bruce, Emma, and Jeremy in the basket returning to the ship.

Figure 2. Don measuring reflectance from the white standard.

Figure 3. A rare sight, beautiful blue skies.

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