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

June 3rd, 2016 by Maria-Jose Viñas

By Walt Meier

A site at the the Inupiat Heritage Center in Barrow, AK.

A sign at the the Inupiat Heritage Center in Barrow, AK.

Jun. 1, 2016 — We started our last day of the camp with a morning visit to the Inupiat Heritage Center to learn more about the indigenous local culture. Many of the Inupiat in Barrow still live their traditional subsistence lifestyle – hunting, trapping, and fishing for food. They do however take advantage of modern technology to make their way of life a bit easier and safer. For example, now machines have replaced dogsleds and rifles have replaced harpoons. But for some things, the old ways did not need to be modernized: the sealskin umiaq kayaks are lighter (easier to carry across the ice) and more navigable in the narrow leads of open water common to the area than anything manufactured today. And the fur-lined coats, pants, and boots are lighter, warmer, and repel moisture better than any modern outdoor gear.

A painting of whale hunting at the Inupiat Heritage Center.

A painting of whale hunting at the Inupiat Heritage Center.

The Inupiat way of life is governed by the seasons. There is a season for whale hunting, for seal hunting, for polar bear hunting. The dark, cold winter season is a time to stay indoors and sew new clothes or repair old clothes. Festivals mark the seasons where the community comes together to celebrate and reinforce the bonds between families.

After visiting the heritage center, we headed back to our base for a final meal. Several times during the week, our field leader, Don Perovich, said that the key for a successful field expedition is “to eat as much as you can as often as you can.” And we were certainly well fed throughout, with plentiful sandwiches, instant soups, chips and crackers, and all-important chocolate for our typical mid-day meals. But our final meal in Barrow was a step above, thanks to Elizabeth Hunke at Los Alamos National Laboratory. She proved herself not only a top-notch sea ice modeler but also a great chef, putting together a delicious meal of spaghetti, garlic bread, and salad.

Last meal in Barrow.

Last meal in Barrow.

Then it was time for our final sessions, presenting the data we collected and discussing our Grand Challenge efforts. Unfortunately, the data collection the previous day did not go as smoothly as we had hoped. We couldn’t collect albedo measurements because the instrument didn’t work yesterday. But this type of things is not at all unusual in field work. As Don said: “In Arctic field research, it’s important to make a plan; it’s also important to not become too enamored of that plan” because something inevitably will go awry and you have be prepared to adapt.

So we couldn’t directly compare one of the key surface features between the two sites. However, we had other data we could look at. The new site to the north was 10-20 centimeters (4-8 inches) thicker than the original southern site. So there was less melt there and the ice was likely to last longer there. And while we lacked some data, we had models we could use. Many people think of modeling simply as predicting the future – and indeed models are used for that purpose (e.g., weather forecasts), but models, particularly climate ones, are also used to investigate processes and learn how climate responds to different parameters. Though we didn’t have albedo data, we could adjust albedo in the model and see how that affected how the modeled sea ice evolves in the future.

Grand Challenge results.

Grand Challenge results.

Several folks worked late into the previous night to process data and run the sea ice model. We obtained climatological weather data, input the data into the model and run it for the first two weeks in June. The results showed that the melt was strongly affected by the albedo of the surface and the amount of incoming sunlight, and that there will likely be substantial differences between the two sites. In a sense this isn’t terribly surprising, but to see such variation over such a small distance (the two sites were separated by only a couple miles) and within such short time periods (two weeks) is sobering. Large-scale complex models and satellite data cannot (yet) resolve such variability. There is still much research to do, and those of us at the camp have come away a greater appreciation for the challenge.

We finished up by discussing future plans. The goal of this camp wasn’t simply to get everyone together for one week, but to start new collaborations between modelers, satellite folks, and field researchers. We discussed several ideas to build upon the start we’ve made, keep momentum going, and convey what we learned to the broader sea ice research community. With that, it was time to head to the airport and begin our long journeys home.

Another tradition Don has is to bring a lollipop to each field expedition. When the expedition is done, he pulls it out as a reward for a job well done. At the beginning of our camp, he gave each of us a lollipop. It was up to us to decide when we were done. Some pulled theirs out after we wrapped up the meeting; some enjoyed theirs at the airport. I waited until the plane left the ground.

And so my adventure on the ice has come to an end. I can’t say I’m an expert in the field or ever will be. But it has been a rewarding week for me. I’ve gained a lot of knowledge about what it takes to do field work. I’ve gained an even greater appreciation of the value of field observations, as well as modeling studies. Hopefully I was able to give participants a greater understanding of satellite data. And finally, now when someone asks me if I’ve been on the sea ice, I can say “Indeed I have!” I still have the taste of the lollipop in my mouth to prove it.

June1_lollipop_finish

Until the next time, Walt.

A Satellite Scientist Visits the Ice, Alaska 2016: Tipping Points, Albedo, And The Local Perspective

May 31st, 2016 by Maria-Jose Viñas

By Walt Meier

May29_Don_demonstrating_albedo_instrument

May 29, 2016 — This morning, we had our second modeling exercise, led by Ian Eisenman of the University of California, San Diego, where we investigated whether sea ice loss is irreversible – i.e., is there a tipping point for sea ice, a point of no return? In the simple models, like the one we used yesterday, once the sea ice disappears under warming temperatures, the ice does not come back even if temperatures cool back down to where they started. This means the loss is irreversible. However, the ice loss is reversible in more sophistical models such as those used for most future climate projections. So are the simple models missing something essential, or do the more sophisticated models get it wrong?

We examined an in-between Goldilocks model –not too simple, not too complicated– and found that the simpler models do miss important processes, such as the fact that heat diffuses into larger regions. This spreads out and slows down the ice-albedo feedback so that if the temperatures cool, the sea ice will come back.

In the afternoon, my group did an optics exercise out on the ice. This primarily involved measuring albedo of the ice. Albedo is basically the proportion of sunshine that gets reflected by the surface. At its simplest, it can be thought of as the whiteness of the surface. A perfectly white surface reflects all of the sun’s energy and has an albedo of 1 and a perfectly black surface will absorb all of the sun’s energy and has an albedo of 0. Albedo is key for sea ice because the ice has a much higher albedo than the ocean. So as temperature rises, the ice decreases, the albedo drops and more energy is absorbed. This added energy warms things further and you get what is called the sea ice albedo feedback, which amplifies the effects of warming temperatures. But the ice doesn’t need to disappear to have the sea ice albedo feedback. Changes on the ice surface – such as melting and ponding – also reduce the albedo.

Measuring sea ice albedo.

Measuring sea ice albedo.

Our goal for the day was to measure albedo along a 100-meter (328-feet) line across the ice. It was our first day here with substantial sunlight; we had blue skies interspersed with clouds. Unfortunately, this was a bad day for albedo: to get good measurements, consistent light is desired. So the intermittent clouds make things difficult. Don told us that normally, if he were in the field in such conditions, he would skip the albedo measurements and drill some thickness holes instead. But we went out and gave it our best effort.

DCIM100GOPROGOPR0025.

In the evening, we had a visit from two native Inupiat whale hunters, Billy and Joe. They told us how hunting bowhead whales is a fundamental part of their culture. The hunters go out onto the ice to the edge of fast ice (ice attached to the coast) and wait for the whale to surface. When they catch a whale, they bring it up onto the ice and share it with the rest of the community. Sharing is part of the fabric of their society – though the hunters make the kills, they are supported by the entire community. At the end of the whale-hunting season in June, there is a big celebration throughout the town with food, music, and dancing.

Because they use the ice to hunt, the Inupiat have intimate knowledge of the ice cover. They have shared this knowledge with scientists; this provides a valuable complement to our scientific data because they see things that satellites, models, and even scientific field observations don’t. For example, they can sense the softness of the ice, indicating a weaker ice cover. They also provide a long record from their personal observations and oral histories passed down over generations. The hunters mentioned how the fast ice used to extend at least 4 miles from shore, but now it only about half that distance. The ice moves out earlier as well, which affects their seal hunting. Also, there used to be a lot of multiyear ice in the area, but now it is rare.

The Inupiat work with the scientists to better understand the changes in the sea ice and their changes on the community. The scientists also help Inupiat by providing data and scientific guidance. With the changing ice conditions, going out on the ice has become more dangerous for the Inupiat – ice floes can break off without warning, stranding hunters. They now can use the Barrow sea ice radar to see how the ice is moving to get a sense of when and where it is safe to go out onto the ice. It was really interesting to hear the perspective from the local community, an essential source of knowledge that provides a view of sea ice that we scientists don’t get in the field, in our models, or in our satellite data.

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!

Notes from the Field