Jennifer Hutchings

Jennifer Hutchings and a team of researchers headed north to the Arctic Ocean in April 2007. Their destination was the Applied Physics Laboratory Ice Station approximately 190 miles north of Prudhoe Bay in the Arctic's Beaufort Sea. Hutchings, a physicist at the International Arctic Research Center at the University of Alaska, Fairbanks, studies the mechanics of sea ice, and for now, the Beaufort Sea offers up plenty of fodder for her study.

Every summer the pack of ice that circulates throughout the Arctic Ocean shrinks as the ice melts, and every winter it builds back up. The specifics of this cyclical pattern–how much ice melts and reforms and when–varies year to year, and researchers aren't entirely sure how a variety of factors affect these patterns. As the global climate warms, they are intent on better understanding this process.

The 2007 Sea Ice Experiment: Dynamic Nature of the Arctic (SEDNA) project, which Hutchings led, measured the movements and dynamics of the Beaufort ice pack. In an effort to better illuminate the effects of global warming, the Bulletin spoke with Hutchings about the state of Arctic ice pack research.

BAS: Why is it important to understand how ice melts in the Arctic?

HUTCHINGS: Sea ice is at a critical phase. It only takes a small increase in temperature for you to see dramatic changes to the Arctic ice pack. And when you see these dramatic changes, you can see a reduction in the total area of ice, which is what we've seen in recent summers. This reduction affects the albedo of the Arctic Ocean as a whole. Because the ice is white, it reflects solar radiation back to space, and if you have less ice, you see less solar radiation reflected back to space. More is absorbed by the ocean, and that can act to melt more ice. If, during the summer, you have a thin ice pack that melts out early, the melt is going to be accelerated by this albedo feedback. We're trying to understand how the dynamics of ice in a previous winter affects the albedo feedback and how it affects the summertime minimum ice pack.

BAS: What type of data did you collect on the ice pack during your 2007 field experiments?

HUTCHINGS: The best way to think of the ice pack is to compare it to plate tectonics. In the ice pack, though, the plates are moving much faster than they do in the solid earth. Stress builds up in the ice when weather systems move across it, and that stress is dissipated through failure of the ice. Climate models typically model ice as a plastic material, so this failure happens along linear discontinuities. The pieces of broken ice slide against each other, and those linear features form leads [channels of water] where the ice pack opens up in a long linear feature.

We typically find that over hundreds of kilometers where you have these linear discontinuities, the leads line up, and they form along a band that's typically about 10 kilometers wide. It's a very fine feature compared to the scale of the pack ice, but that's where all of the deformation in the ice pack is occurring.

These leads are very interesting from a climate perspective, and for the oceanography of the area too, because when the ice pack opens up, you have a huge heat source to the atmosphere. The ice is essentially insulating the ocean from the atmosphere, and that's why you get very cold temperatures in the Arctic. When a lead opens up, you can grow new ice, and if the lead closes, you build these huge ridges, which can be 40- to 50-feet high.

When the ice pack closes up it's weak to compression, so the two plates will ride up against each other. Again, it's very similar to plate tectonics. It's like you're building a mountain range, except the ice breaks into blocks. The keels, the portion of that ridge that's below the water, are much larger than the sails, the portion above, due to buoyancy. What we're interested in, in this experiment, is how much of the ice is being redistributed into these ridges, and how much new ice we're seeing growing in leads.

BAS: Why is it necessary to understand this?

HUTCHINGS: The yield criteria that's been developed for sea ice models is based on a set of assumptions about how ice behaves, and these assumptions were developed during large field campaigns in the 1970s–the AIDJEX field campaigns. We now know that some of those assumptions are untrue, such as that ice fails isotropically [in all directions equally]. It doesn't. We now know that these huge failures are traveling 500 kilometers through the ice pack–that's anisotropic behavior.

BAS: Does the size of the data set on sea ice increase the accuracy of the models?

HUTCHINGS: I don't think the size of the data set matters. I can have a very small data set based in the Beaufort Sea, which is what the SEDNA project is, and because ice behaves the same across the Arctic Ocean, I can extrapolate from this project as to how ice is going to behave in the Laptev Sea. What I'm trying to get at is the geophysical properties of the ice, and when weather systems go across, how does the ice fail? The main problem with prior projects is that they simply did not have the technology to be able to bring all of the data together into a coordinated data set.

The best way to think of the ice pack is to compare it to plate tectonics. In the ice pack, though, the plates are moving much faster than they do in the solid earth. Stress builds up when weather moves across it, and that stress has to be dissipated through failure of the ice.

BAS: Have the dynamics of sea ice changed over time?

HUTCHINGS: This is one question we have asked ourselves. I recently wrote a paper with Ignatius Rigor [a scientist at the Polar Science Center], and we were looking at deformation of the ice pack in the Beaufort Sea during winter. There are indications from buoy motion collected over the last 30 years that the ice pack is now opening more in the late winter. This could be because the ice pack is thinner and therefore weaker, and more susceptible to opening. It could also be because there's an increase in the number of storm systems going through this area, which is opening up the ice pack. This is very interesting, because when the ice pack opens up that dramatically in the late winter you end up with areas of thin ice that grow across the leads. That thin ice then melts earlier in the summer, therefore enhancing the albedo feedback. So yes, it is very likely that ice pack dynamics have changed dramatically in the last decade.

BAS: What are some of the other mechanisms that are causing sea ice changes?

HUTCHINGS: On the Eurasian side of the Arctic, there's a strong indication that the changes in the ice-edge minimum are strongly correlated to the atmospheric temperature during the summer. Whereas that's less the case in the American and Canadian Arctic.

In the Arctic system, the ice is confined by land and circulates around the Arctic Ocean, eventually exiting through the Fram Strait. In the Canadian and Alaskan Arctic, the ice tends to be older, because it's been circulating back on itself for many years. Therefore, the ice at the lower latitudes is ultimately less susceptible to variability. When you're looking at the ice extent, it's less susceptible to variability in surface temperature during the summer, simply because the ice can withstand larger temperature changes. That has been changing in the last decade, where we're seeing a younger ice pack in the southern Beaufort. In the Laptev Sea, the ice regrows every year, you're in a marginal ice zone, and therefore the interannual variability is more susceptible to changes in the surface air temperature.

What we're seeing is that an increase in surface air temperature in the Arctic is probably having an effect on the ice, as are changes in storm tracks into the Arctic. The other factor that is interesting is the change in the Pacific water inflow. The Pacific's water comes in through the Bering Strait, and it's actually very close to the surface–about 20 meters below the surface. That Pacific water has been observed to extend further out into the Chukchi and Beaufort Seas, and this might be releasing more heat into the layer of water below the ice and helping melt the ice.

BAS: If the climate weren't warming, would the sea ice still be quaking, thinning, and melting?

HUTCHINGS: During every winter the ice quakes, and during every summer the ice melts. I, for one, am not sure that we can distinguish between natural and anthropogenic forcing in the case of sea ice. That's because it's such a highly non-linear system that each one of these mechanisms is affecting the ice pack dramatically. We can't say how much of the ice mass loss can be assigned to either one of these causes.

What we're trying to do at the moment is to understand the magnitudes of the feedback. What is the impact of wintertime dynamics on the summertime ice mass? We're not really at the stage of being able to look at all of the forcing going into the system and to understand how the system responds to changes.

BAS: How do you respond when the media or public suggests that your research disproves the impact of humans on the climate?

HUTCHINGS: I find that frustrating, because it's so shortsighted and narrow-minded.

We're trying to say that the system is changing–it's changing dramatically. What's more interesting is that the system has this potential to change to such an extent. At the moment, we don't understand if this is something that has happened since the last glacial maximum, or not. All indications are that this is something that's unique.

Is the loss of sea ice a precursor to a dramatic change in the ice pack, where we could lose all perennial ice and go into a state where we have very low ice pack in the summer? If that is the case, the climate models indicate that the Arctic climate will go into a dramatically different state, and that's going to have huge implications for the global climate and for the weather the United States experiences. The fact that the ice system has the potential to flip into that state is interesting.

In general, I don't think the question of causality should be the lead question that determines policy. It doesn't change the fact that we are seeing change. Whether that change is driven by natural forces or by humans, it's still going to dramatically impact human society. We need to address how it's going to impact society, and how we're going to react to it. The more knowledge you have, the better for making a plan to react. Which is why I think my work to try and understand how well global climate models are representing sea ice is actually relevant.

Whether change in the ice pack is driven by natural forces or by humans, it's still going to dramatically impact human society. We need to address how it's going to impact society, and how we're going to react to it.

BAS: How do we know if ice loss has reached a tipping point?

HUTCHINGS: We'll know in the next decade if we have reached the tipping point. Basically, what we're looking for is an ice-free summer. At the moment, we really don't know what the natural variability is in the ice pack over a century time scale. The mass of the Arctic ice pack has approximately a 10-year memory. During the last decade, the ice pack has gotten younger, which means that the memory of the ice pack is becoming shorter. A tipping point would be if we get to a place where the Arctic Ocean is unable to maintain a perennial pack. It would then take a dramatic change in the climate to rebuild an older ice pack. We're not at that stage yet, because we still have a perennial ice pack that's still circulating around the Arctic, but I'm not confident that the perennial ice pack can survive the current situation.

We could also have a few years where the winter weather systems allow for the propagation of the Beaufort Gyre and allow the ice to recirculate in the Arctic. Then we would have an older ice pack, and we would lose less ice the following summer. So, you could envision a scenario where we're not going to precipitously lose ice over this next decade. We could rebound a bit, but then, we could start losing ice again. It's very hard to determine what's going to happen.

BAS: How did the Arctic ice pack fair during this last summer?

HUTCHINGS: We saw less ice loss in the East Siberian Sea region. I hope to talk to some colleagues who have been out to that region, because the only way you can really get a handle on what the ice pack is doing is through visual observation. Given the type of ice that's in that sector right now, I imagine it's fairly thin at the moment. The Beaufort Sea has had the largest melt back of ice I have ever seen in a summer. I was a little surprised by that, but it follows from what I was expecting with this trend in the Beaufort Gyre.

BAS: Is the international cooperation that has been a hallmark of Arctic research being threatened as sea ice melts?

HUTCHINGS: It's certainly interesting, isn't it? There have always been nuclear submarines under the ice, and, actually, the scientific relationship with U.S. nuclear submarines and the British nuclear submarines is very good. The U.S. Navy has collected data on ice thickness for scientists since the 1990s, as part of the SCICEX program. So, there's been a lot of incredible collaboration between the navy and scientists in understanding Arctic change.

The sovereignty issue in the Arctic today is very interesting, particularly now that the oil industry is rushing to explore the Beaufort and Chukchi seas. I'm not sure how that's going to affect scientists. There's the potential for a little more money for scientists, as environmental regulation becomes more important in the Arctic, and as the oil companies want to understand more. They will be very interested in how ice dynamics may affect their operations; where they can put their platforms; and how to work in that environment.

At the moment, though, there seems to be very little interest in creating international treaties for preserving the Arctic, and for ensuring that we don't have environmental catastrophes. That probably needs to be done on an international scale. I've seen some very interesting ideas about the economics of the Arctic, and how its economic system can be pushed. This type of system is either business led, nation led, or regulatory led, and outcomes will vary based on which is the driving force. At the moment, scientists are not the driving force. We're just taking whatever opportunities we can to improve our own understanding.

BAS: The public hears so much about sea ice loss in the Arctic and not so much about activity in the Antarctic. Is the ice melting there too?

HUTCHINGS: Well, in the Antarctic, we actually saw a slight increase in the area of ice during the last several years. A downtrend recently restarted. But the changes to the sea ice in the Antarctic have not been as dramatic. In part, that's because the ice in the Antarctic is very different dynamically from ice in the Arctic. The Antarctic ice pack is basically a seasonal ice pack apart from some isolated patches in the Weddell Sea and close to the continent. And the ice pack is bounded by the circumpolar current, so we're not seeing such dramatic changes because they're masked by the seasonal cycle. In the summer, when you would see the most dramatic changes, the ice is retreating rapidly anyway. Some of my compatriots would tell you that the climate warming signal has been masked due to the cooling effect of the ozone hole, so we might see accelerated ice retreat as this hole repairs itself.

We're not able to measure ice thickness very effectively in the Antarctic either. So we're not really sure what's happened to the massive Antarctic ice. We only really know that the extent has stayed fairly level during the last 50 years. We can't say that we haven't lost ice in the Antarctic, on the other hand I wouldn't expect us to have either.

BAS: How unusual was it to lead your research team with another woman?

HUTCHINGS: Very. Well, Jackie Richter-Menge, who is a coprincipal investigator on this project, has worked in the field since the 1970s, and she said this was the first time that she wasn't the only female principal investigator on a project. I believe she really enjoyed the experience. Jackie, Cathy Geiger, and myself conceived of the idea for the project in 2005, so we spearheaded it. But we do have many male coinvestigators. For me, it was my first experience working with a team of women.

BAS: How was it different?

HUTCHINGS: It was less isolating, I would say. I felt much more comfortable working in that environment. Having gone through a physics degree and PhD, I have mostly worked with men before, so it was a different experience.

BAS: Do you think the gender gap matters when doing scientific research?

HUTCHINGS: I think the gender gap is closing; I see far more female graduate students. And I don't think it matters so much. But yes there are subtle differences in the way the two genders work, and I'm hoping that because we have females spearheading this project, that maybe it will be a little more collaborative.

When we were talking about who would be chief scientist at the ice camp, I thought Jackie should be, because she was the most experienced. Yet Jackie didn't want to do it. She thought I should do it, because I had written the proposal, and Cathy had other skills that should be rolled in. I'm kind of shy, so I was a little bit worried about having to work with 30 people in an ice camp, when I'm probably the least experienced of the group. So we approached the navy and asked them to share the role of chief scientist. And they just went, “Absolutely, not!” I was scratching my head about this–why would it never work? With the right mix of personalities, it can work, but the navy believed we weren't very likely to have that right mix of personalities to make it work, so we went with the standard model with one chief scientist.

BAS: What is day-to-day life like at the Arctic ice station?

HUTCHINGS: Well you're out in the cold all day, so you want to have a lot of good food! It's very comfortable if you compare it to the Russian ice camp, which I have never been to, but I've heard stories. I think we had it quite easy. We're in pretty cramped quarters–six people to a twelve-by-twenty hut–and we tended to work hard all day, and then just go back to the hut to sleep. We have a short time out there, so it's intense. We're collecting as much data as we can, so it all goes by in a bit of a blur. You come back, and you're utterly exhausted because you've been working so hard, and then you feel great.

What I like about working out there is just how beautiful the environment is. You get to spend all day outside in the most fantastically beautiful environment.

BAS: What was the most memorable scene from your time up there?

HUTCHINGS: Sunset. It's very different from South Africa where I lived as a child, because in Africa, the sunsets are red from the dust in the atmosphere. The sunsets are more pinky orange in the Arctic, and they last an incredibly long time. While we're there between March and April you go over the Equinox, so you go from dark nights to light nights in a short period of time. You're watching the aurora one night, and then the next week, the aurora can't be seen anymore. It's pretty dramatic to experience that.

BAS: How has the SEDNA project bridged the communication gap between researchers and the public?

HUTCHINGS: We've had some fun with that. We had a teacher up at the ice camp who Cathy was working with. His name's Robert Harris. It was great working with a teacher, because he was interested in our work on a very different level from the way we're interested in it. He was interested in the experience of being involved with science, but also would ask the kinds of questions that you're asking, to make us think about what we're doing and to explain what we're doing to schoolchildren. It was enlightening to work with him. He had teleconferences with school kids while he was at the ice camp, which brings it home to us that we're not completely isolated from the rest of the world. That we're not just working out here on something completely esoteric is a nice thing.

BAS: Do you think the public understands the implications of climate research?

HUTCHINGS: I don't think it's often portrayed well enough for the public to understand it. The general media tends to just like the big headlines that say, global warming or ice melts. They don't really explain the context of what we're seeing very well. When I talk to people who don't have a scientific background, they are absolutely fascinated by the climate and the weather and the world they live in. So I think that the media could do a better job of explaining the science, but maybe the scientists could also do a better job. I certainly fall down here, because I find it very hard to talk about my work on that level. It's a difficult problem.

What needs to register for the public is not that climate change is somewhere far away, only affecting polar bears, but rather that the whole climate is interconnected, and that the ice melts in Greenland and the ice on the Arctic Ocean really impacts the climate in the United States. For example, there've been some studies looking at droughts in the southwest United States and how they are connected with climate change in the Arctic. These kinds of studies are very important, especially when it comes to public understanding.

BAS: Why doesn't the public ever see any pictures or reporting on the impacts that melting ice is having on indigenous populations in the Arctic?

HUTCHINGS: I interact with a lot of scientists who work out of the Barrow Arctic Science Consortium. The population in Barrow is incredibly interested in sea-ice science, because they're interested in maintaining their culture, and they're interested in whaling and how their livelihood is changing because of changes in the ice pack.

It's hard to distinguish between the socioeconomic change and the changes due to climate, but they've seen dramatic changes in the pack ice, which is making it more difficult to predict when the ice is going to break out, which has implications for hunting on the sea ice. In the past, according to their local knowledge, they didn't have such immense problems in predicting what the ice was going to do.

And then there are other communities in Alaska that are losing coastline very rapidly. This coastline has always been in transition; it's always been moving. But now the increase in summer ice extent could be increasing storm activity and accelerating erosion. The need to relocate villages in Alaska is dramatic. It's something that needs to be addressed right now. These villages are falling into the sea.

BAS: Do you think that humans should make a concerted effort to grow back the ice? Is there even a recipe for growing ice back?

HUTCHINGS: In the current state of knowledge about sea ice change, I would say yes, it is possible, that we could see the situation return to the realm of natural variability during the next 10-20 years. However, all of the climate models indicate that the ice pack will disappear. Whether the climate models are right is another question. And if the ice is on a path to being a seasonal ice pack, it is possible that we've already gone over the threshold. I don't know whether that's true or not, but the climate models could indicate that. In which case, it would be very difficult to grow it back.