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A Satellite Scientist Visits the Ice, Alaska 2016: Sea ice morphology and charismatic mega fauna

May 31st, 2016 by Maria-Jose Viñas

By Walt Meier

Walt Meier on a snowmobile.

Walt Meier on a snowmobile.

May 27, afternoon – After our morning orientation and introduction sessions, I headed out onto the ice for the first time. We were split into four teams; each team will rotate through a different activity every day with each activity being led by one or two experts that will serve as our guide. I was assigned to the Red Team. Our activity for the day was sea ice morphology, or studying the forms of sea ice, and it was led by Chris Polashenski at the U.S. Army Cold Regions Research and Engineering Lab and Andy Mahoney at the University of Alaska, Fairbanks. All the other activities were being conducted within a short walk of the beach, but in order to see different types of ice, we needed to roam farther. This meant using snowmobile. After getting comfortable on the machines, we headed out. Our first stop was on a first-year ice floe, or is ice that has grown since the previous summer. This type of ice is generally thinner than multi-year ice (ice that has survived at least one summer melt season) and its thickness is largely controlled by the air temperature during the winter (though how much snow falls is important too). Colder temperatures mean more ice growth and thicker ice at the end of winter. We measured the thickness by drilling a hole through the ice using an auger. Then we dropped down a measuring tape. The tape has a folding metal bar at the end that catches the ice at the bottom of the hole; the tape is pulled taut and the thickness is read off the tape.

An ice mass balance station in Barrow, AK.

An ice mass balance station in Barrow, AK.

According to Chris and Andy, first-year ice in the area normally should be about 1.5 meters (5 feet) thick. We measured only 0.75 m. That means it’s been a very warm winter around here. But that is nothing new; in recent years, warm winters have become the norm as indicated by thickness measurements. For the past several years, Andy has been installing a sea ice mass balance station on the ice, automatically taking thickness readings every 15 minutes through the winter. The data is available online here.

A polar bear in the distance.

A polar bear in the distance.

Next we head further north, past Point Barrow, the northernmost land in the U.S., toward the fast ice edge. On the way, we spotted two polar bears in the distance. Polar bears are not an uncommon sight. They usually hang out near the ice edge hunting seals, though they sometimes wander into town, which can be a problem. At this time of year they are attracted by the whale carcasses that the native populations pull onto the ice as part of their traditional whale hunts. The bears were distant and barely visible, but it was quite exciting to see a bear. Polar bears can be dangerous and during all of our activities on the ice, we will have a polar bear spotter –a trained local resident carrying a shotgun – with us at all times.

We left the polar bears to their business and rode further out to a multi-year ice floe that was more than 5 meters (16.4 feet) thick. We attempted to measure the thickness, but we didn’t break through the bottom of the ice at our auger’s (boring tool) maximum 5-meter length. To my untrained eye, the multiyear ice didn’t really look much different than first year. But with careful viewing, one could see an elevation change compared to the first-year ice. It wasn’t a lot, but a just little more elevation on the surface that floats above the ocean translates into much thicker ice because roughly 90 percent of the ice thickness lies beneath the surface of the waters. So a 5-meter thick floe of sea ice rises only about 50 cm (20 inches) above the waterline. The most distinguishing characteristic, at least at this time of year, are the brilliant blue melt ponds that form on the surface. As the snow melts, the melt water will accumulate in depressions in the ice, pooling into ponds. The crystal clear water on top of the pure multi-year ice produces a distinctive turquoise color reminiscent of the water around a tropical island. Melt ponds are very important because they absorb much more solar energy than the surrounding ice, which accelerates the melting process. But to be honest, when seeing a pond in person, the first thought one has is how pretty they are.

May27_meltpond

Walt, standing on a melt pond.

Walt, standing on a melt pond.

Just a few meters away, back on first-year ice, was another melt pond. But this had a much darker color due to the thinner and flatter ice. The water was also somewhat salty because first-year ice still retains some salt. The salt gets flushed out of the multiyear ice, so the blue ponds on the multiyear ice are fresh water suitable for drinking. We tried some and it was quite refreshing – ice cold!

May27_meltpond2

Next, we headed over to a large piece of ridged ice. Ice ridges form due to ice floes being piled into each other due to winds or waves. The fast ice does not move, but the drifting ice beyond does and when the winds blow toward the land, the drifting ice collides with the fast ice, forming mountains of ice. The one we investigated was around 5 meters (16.4 feet) high. This means the ice could extend 50 meters (164 feet) deep below the surface. However, the water is fairly shallow off the coast and in reality, the ridge was likely grounded to the sea floor. These grounded ridges actually stabilize the fast ice by acting like big support columns, holding the fast ice in place. This explains why the coastal ice remains in place long after the drifting ice has retreated.

The morphology activity was quite humbling to us satellite data scientists and modelers. We work at scales of 5 to 50 kilometers (3 to 31 mi) – i.e., we’re observing or modeling sea ice in 5-50 km aggregates. Here over just a few kilometers we saw a tremendously varied icescape. Even over just a few meters, we saw multiyear ice, first-year ice with melt ponds on each. How can interpret our satellite data to account for such variability and how can we simulate it the models?

With the ridged ice, we completed our tour of the various forms of ice found in the Barrow area at this time of year. We hopped on our snow machines for the ride home. In front of us the sun broke through the clouds, behind us the polar bears roamed, and all around us, a lovely landscape of ice.

A Satellite Scientist Visits the Ice, Alaska 2016: Beachfront Resort

May 27th, 2016 by Maria-Jose Viñas

By Walt Meier

the house

I have arrived in Barrow, Alaska. It was an interesting flight up from Anchorage: the plane had seats only in the back half of the plane because the front half is used for cargo. That is because there are no roads into Barrow, so supplies need to be brought in by plane or, during the short summers, by barge. After a stopover in Prudhoe Bay, we arrived to gloomy skies, which are quite typical for this time of year. Temperatures are right around freezing. We are staying at the NARL, which originally was the Naval Arctic Research Laboratory. Various research groups and other activities –even a college– now share this facility.

The accommodations are spare, but comfortable. Most people are staying in Quonset huts (prefabricated huts made of galvanized steel), but I’m with four others in “The House”, which is more like, well, a house. We have a living room, kitchen, full bath, and four bedrooms. Because we have a kitchen, we are the base for meals where the whole group meets up to eat breakfast and lunch. Last night we all gathered for a light meal after arriving and, with 24 people, it got pretty crowded. But it was nice to catch up with old friends and meet new colleagues. Already the collaborations have begun as we informally discussed each other’s research.

The whole campus is on a narrow spit of land north of town sticking out into the Beaufort Sea. I can see the sea ice from the house. So you might say we’re staying at a beachfront resort! With the ice right out the window, it was tempting to take a walk out there last night. However, we were told to not go out on the ice until we get a safety orientation. The ice off the coast is landfast ice – ice that is attached to the coast, so it doesn’t drift with the winds. However, it can still shift with the tides, as evidenced by piles of ice ridged formed as ice got pushed together. So one doesn’t want to just run out on the ice without being familiar with the hazards. Oh, and there are also potentially polar bears roaming around – another very good reason not to go roaming off by oneself.

Our view of sea ice from The House.

Our view of sea ice from The House.

Now we’re heading off to our orientation session and introductory discussions where we’ll start learning about modeling, satellite data, and field observations. This afternoon we’ll take our first trip out onto the ice. When the week is over, each of us will have broadened our expertise beyond each of our core research areas and hopefully we may find new areas of research to collaborate on and advance our understanding of sea ice.

A Satellite Scientist Visits the Ice, Alaska 2016: A Satellite Scientist Visits the Ice

May 26th, 2016 by Maria-Jose Viñas

By Walt Meier

Walt Meier

Whenever I tell people that I’m a polar scientist or that I study sea ice, inevitably one of the first questions I’m asked is, “so, have you been to the ice?” I’ve always had to answer no. I’m a remote sensing scientist who works with satellite data. Other than a few aircraft flights over the ice several years ago, I’ve spent my career in front of a computer analyzing satellite images. When I’ve needed field data, e.g., to validate satellite measurements, I could always obtain it from colleagues. So there has never been any need for me to go out on the ice. And to be honest, spending days or weeks in the field, as many researchers do, does not have particular appeal to me – I like the comforts of my heated office! Nonetheless, I’ve always wanted to get out at least once in my career and see the ice close up, feel it crunching under my feet, hear it creak and groan as it strains under the winds and currents.

An image of sea ice in northwest Greenland, capture by NASA's Operation IceBridge.

An image of sea ice in northwest Greenland, captured by NASA’s Operation IceBridge.

Now I am getting that chance, thanks to a National Science Foundation funded Summer Sea Ice Camp workshop. I and a couple dozen fellow scientists are heading to Barrow, Alaska – the northernmost point in the United States at 71 degrees N latitude – to partake in a unique project. The goal of this project isn’t specifically to collect data (though I hope that some of the data we collect will be useful), but rather to foster communication between remote sensing scientists like myself, sea ice modelers, and field researchers.

While there is a lot of collaboration in the sea ice community in terms of sharing data and results, scientists tend be silo-ed within their own area of expertise when it comes their actual work. Modelers focus on model development, validation, and results. Remote sensing folks like myself analyze satellite data. And field researchers collect and analyze in situ observations. Partly this is simply due to time – just focusing on one area keeps one plenty busy. But it is also partly due to a lack of communication. For example, I know a bit about modeling, but I don’t really understand the details of how a sea ice model is put together, how it can and should be used. Similarly, while modelers often use remote sensing data to compare with their model results, they don’t often understand the capabilities and limitations of satellite data. This can lead to under use or misuse of the data. And neither modelers nor remote sensing scientists may have much understanding of how to best take advantage of in situ data.

The goal of this workshop is to bring the three groups together for a week to talk and work with each other to better understand each of the three specialty areas and how perhaps the three groups can better work with each other to advance our understanding of sea ice. So now I’m on my way to Barrow, Alaska, looking forward to helping others understand satellite data, as well as running sea ice models and feeling that crunch of ice and snow under my feet as I collect data from on top of the Arctic Ocean. More in my next blog post from Barrow!

Nansen Ice Shelf, Antarctica 2015: The End of Our Adventure

January 11th, 2016 by Maria-Jose Viñas
Credit: NASA/Christine Dow

Credit: NASA/Christine Dow

By Christine Dow

We have arrived back safe and sound after 11 days crossing the Southern Ocean. Our exit from Jang Bogo involved one last (very short) helicopter ride taking us to the Araon icebreaker so that they didn’t have to re-break ice to get back into port. I stayed up till the wee hours on the top deck watching us motoring away from my home for the last month, pushing large chunks of sea ice out the way. Some Adélie penguins were also witness to our departure along with snow and cape petrels diving and swooping around the wave tops. It was a very idyllic sight and I was sad to say goodbye to the Antarctic (until next time).

Credit: NASA/Christine Dow

Credit: NASA/Christine Dow

Onward ho. Over the next few days we crashed and bumped our way through the sea ice. This was a good chance to get used to the (very) rolly motion of the boat. Icebreakers are designed with highly rounded keels, excellent for smashing through ice packs but not so great on the stomach. A very good distraction was the on-board table tennis table. Many doubles games were played over the course of the voyage, some more successful than others depending on whether the boat allowed both balls and players to be on a sensible trajectory.

Credit: NASA/Christine Dow

Credit: NASA/Christine Dow

After two days, we were almost out of the sea ice pack when we suddenly had to turn around and return south. There had been a distress call from a fishing boat stuck in the ice and R/V Araon went to the rescue. We successfully hauled the boat free from the ice that it had become wedged on and escorted them to a region easier to navigate through. On the return journey we also stopped to collect some long sediment cores that the Korean scientists will analyze later.

The timing of our journey meant that we had Christmas on board the boat. Our party was on Christmas Eve and involved a veritable feast – the chefs had been very busy all day kindly preparing this for us. One of the Korean scientists also played some clarinet and saxophone music to get us in the Christmassy mood. We even had a Christmas tree, lashed to a railing to stop it flying all over the place.

Credit: NASA/Christine Dow

Credit: NASA/Christine Dow

On the 11th day of our journey we could see land. It was very strange to see trees and green again after so long with just hues of blue and white. We had also been slowly getting used to the dark as we moved north following our time in 24-hour daylight; the first sunset of the voyage had been spectacular with giant albatross swooping behind the boat. I watched as we finally docked at the port of Lyttleton in New Zealand, feeling that “normal” life would be a little surreal after our adventure. It was time to say goodbye to our friends and colleagues and go home, just in time for the New Year. After such a trip it’s not surprising that one of my resolutions for the new year is to get back to the frozen continent…some day.

Nansen Ice Shelf, Antarctica 2015: Final Data Collection and Farewell to Jang Bogo

December 15th, 2015 by Maria-Jose Viñas

By Ryan Walker

Credit: NASA/Christine Dow

Credit: NASA/Christine Dow

Before it was time to recheck our GPS stations and download data from them, the icebreaker Araon arrived at Jang Bogo, bringing new scientists, a new helicopter crew, fresh food, and other supplies. Because of heavy sea ice cover on the bay, the arrival was in slow motion, taking most of a day from the time the ship was visible from the station until it stopped a few hundred yards offshore due to unbreakable eight-foot-thick ice. Thick ice often requires an icebreaker to back up a considerable way, then charge forward into the ice, breaking through either by pure impact or by sliding the bow up onto the ice, causing it to collapse under the ship’s weight. One passenger told Christine and me that it was “like being in a car crash — all day.” We’re quite happy that there will already be a clear path out of the bay when we take the Araon back to Christchurch. Before leaving again for a roughly week-long science cruise, the ship also dropped off quite a lot of equipment for the various science teams, including most of the instruments to be installed by our hosts, the Extreme Geophysics Group. This meant that the time between Araon’s departure and return would be very busy, with limited time to install instruments before most of the scientists leave on the ship. On top of this, we had several days of bad weather that prevented any helicopter flights. In order to finish our work on the GPS stations, we had to squeeze into a busy flight schedule, which meant that Christine and I would go on separate flights.

Credit: NASA/Christine Dow

Credit: NASA/Christine Dow

I was on the first flight on December 10, which began with Dr. Choon-ki Lee installing a new GPS station on a large piece of ice at the front of Nansen Ice Shelf that looks ready to calve off into a tabular iceberg. There’s a huge crack, miles long and sometimes over a hundred yards wide, which runs more or less parallel to the front of the ice shelf. Over the winter, the sea surface freezes and traps small icebergs in the crack, producing a fascinatingly broken icescape. Comparing ice velocities between this new GPS and our stations should let us monitor the calving process and learn more about how it works. When we moved on to check the first of our GPS stations, I found that it wasn’t operating at all. After checking the wiring, I worked out that the problem was either in the wire to the receiver, the regulator (the electrical component that connects the solar panel, battery, and receiver), or the GPS receiver itself (potentially big trouble) — but had no idea which one. I pulled out those three components to check back at Jang Bogo, and we secured the rest of the station and moved on. Fortunately, after an unpromising start, the two other GPS stations we visited were working perfectly. While downloading the data, which involved about fifteen minutes of connecting my laptop and then sitting on the ice typing obscure commands, I was amused by how much this aspect of field work resembled the computer modeling work I usually do, though with vastly better scenery. We then returned to Jang Bogo with two stations in good shape, two yet to be checked, and one hopefully to be repaired.

Christine says: It was getting worryingly close to the time when we would be leaving the Antarctic and we still had some data to collect and the GPS to fix. I found that the GPS problem had been due to a faulty solar regulator and replaced it with a spare back at base. Luckily I managed to piggy back on a flight out to the Nansen Ice Shelf with the Extreme Geophysics Group while they were putting out seismic stations. Replacing the GPS was quick, with the satellite lights blinking encouragingly; now we just have to hope the system will continue working for the next couple of months. At the next station, I downloaded the data while wind blew some loose snow all over me and the computer. I probably looked a little like a snowman by the end of that. The final job was to replace the tethers on the last GPS (see our previous blog post). It was not without sadness that I waved goodbye to the plucky little machines, which would sit out on the ice on their own until the end of February. At that stage one of our Korean colleagues who is overwintering at Jang Bogo will collect them for us and send them back on the ship.

Speaking of the ship, we’re off. It is due to arrive tomorrow and we will set sail for our 7-10 day ‘cruise’ back to Christchurch in New Zealand. Its hard to believe we’ve been here 5 weeks already and it feels a bit strange to be packing up and leaving. We’re hoping for some wildlife spottings on the boat and more importantly not to be completely debilitated by sea sickness. Internet is not readily available on the Araon so we will report back when we reach dry land. Wish us luck!

Goodbye, Jang Bogo! (Credit:NASA/Christine Dow)

Goodbye, Jang Bogo! (Credit:NASA/Christine Dow)

Notes from the Field