Applied Ocean Physics & Engineering Department
Your research focuses on upper ocean and sea ice interactions and sea ice physics. How did you become interested in this field?
I'm generally really interested in understanding how sea ice, which is the ice that forms from the freezing of seawater, is changing in both the Southern and Northern Hemispheres. Most people probably have some inkling that the ice is changing a lot at both poles. We're seeing a lot less sea ice on an annual basis and a lot of that is because the ice is such a thin layer interacting with the upper ocean. I particularly think a lot about how sea ice melts and what that looks like physically. Different physical processes are driving the melting, both from heat that's in the upper ocean and also dynamics like waves and mixing.
I got into this field through my interest in waves. I studied general Earth sciences as an undergraduate, and I became really interested in waves and the role that the energy that waves carry has on coastlines. There are actually a lot of analogs between the way that waves erode coastlines and how they interact with sea ice. By chance, I ended up doing a project for my graduate work looking at waves interacting with sea ice and really fell in love with working in the polar oceans and working on sea ice.
In the Arctic, how waves interact with sea ice is really a new question. On the other hand, the Antarctic is very different because the Southern Ocean has always been very windy and stormy, and there's been a lot of wave action interacting with the sea ice. There’s really a very cool contrast between the two.
That's great, I didn't realize that waves have such a big an impact on sea ice. Continuing off of that, most of your work has focused on the Arctic. How did you become interested in the Antarctic?
The motivation for studying waves and sea ice in the Arctic is largely related to the fact that waves are a new feature in this region. The Arctic is a closed basin where historically there’s been no open water for waves to form. But with the decline of sea ice, we’re seeing a lot more waves interacting with the remaining sea ice. So, in the Arctic, how waves interact with sea ice is really a new question. On the other hand, the Antarctic is very different because the Southern Ocean has always been very windy and stormy, and there's been a lot of wave action interacting with the sea ice. There’s really a very cool contrast between the two. I was excited to explore the difference in the way that waves play a role in the Southern Ocean where a high fraction of the sea ice that forms is impacted by that dynamic environment. Obviously, Antarctic sea ice is changing a lot as well, so the relative role of waves is also changing. So, there are some similarities and also some differences in the way that the processes that we're working to understand will play a role in the two poles.
Very interesting. Do you think what happens with sea ice and waves in the Antarctic is an analog for what will happen in the future in the Arctic?
To a degree, yes, I think some of it is. For example, take pancake ice. Pancake ice is a very fun name, and it's called that because it forms when waves push floes to collide and become round and pancake-like. A high fraction of sea ice in the Antarctic looks like that because of all the wave dynamics, and we're seeing that much more in the Arctic. So, I think there are things that we can learn about the Arctic from the Antarctic.
Can you tell me more about your research in the Antarctic?
In 2017, Steve Ackley invited me on a research cruise to the Southern Ocean for a project called Polynyas, Ice Production and seasonal Evolution in the Ross Sea (PIPERS). From the sea ice perspective, a big goal of that cruise was to understand more about sea ice formation in winter and particularly the role of formation in the marginal ice zone versus the role of polynyas. The marginal ice zone is the ice edge that interacts with the Southern Ocean, while polynyas are areas of open water near the coastline that form due to strong winds blowing off the shelf.
The specific goal that I had within that broader question was to understand the role of waves because of these strong winds. How do they affect sea ice formation and the advection of sea ice? This is important to understand whether we need to be able to capture those interactions when we're modeling and representing Antarctic sea ice. Waves are something that's not traditionally represented in a lot of climate models, but they can play a large role in both hemispheres and especially in the Antarctic. Especially with these localized but regionally very important features like polynyas, it may be important to think more about what the details of those processes are.
Based on what you’ve told me about waves and sea ice, it does seem like there are important processes to incorporate into models. Expanding on your fieldwork, what was your initial impression of the Southern Ocean and how does it compare to the Arctic?
It just feels so expansive and really makes you feel like you're exploring a new place, especially being on the sea ice. For a given piece of sea ice, probably no one has ever been on it before.
It felt more different than I expected! Especially from the perspective of a sea ice scientist, the poles are very different. I think if you plopped a sea ice researcher down on a random piece of ice and gave them a few minutes, they could probably tell the difference between the Arctic and Antarctic because the ice does look pretty different in a lot of ways. There's a lot more snow on Southern Ocean sea ice and it’s largely more dynamic. I was surprised that it felt so different.
But similar to the Arctic, you feel so far away from everything in the Antarctic. It just feels so expansive and really makes you feel like you're exploring a new place, especially being on the sea ice. For a given piece of sea ice, probably no one has ever been on it before.
Something that was nice and different from being in the Arctic is that, especially being there in polar night, you don’t have to worry a lot about polar bears. It's hard to see and keep watch for polar bears during polar night in the Arctic. You have a very different wildlife around you in the Antarctic.
I think I prefer penguins over polar bears! So, you were down there during austral winter?
Yeah, it was early winter, April to June. That's really when the winter is kicking off, and it’s full darkness in June.
Most people I know do their polar fieldwork in the spring or summer, but it makes sense that you would want to be out there in winter, when the sea ice is starting to form.
Yes, with polar work, there is a bias towards going in the summer because that's when it's easier to do a lot of the science. But then there's a real dearth of observations in the winter and in the shoulder seasons when a lot of rapid changes happen. Since the seasonal cycle is a big part of the long-term trends we're observing, we need to better understand the pieces of the system that we're not typically measuring with summer observations.
Aside from better understanding seasonal dynamics, what future Antarctic research are you excited about? Are there connections with your Arctic research?
Currently the work that I've been doing that relates to the Antarctic is thinking about how we can apply what we've learned about Arctic sea ice from recent expeditions to see if we can improve Antarctic sea ice projections. When we think about sea ice modeling, any of the models that we're using for the globe have to work in both hemispheres. So, any of the new parameterizations that we develop from Arctic observations also have to work for Antarctic sea ice, too.
In that direction, I have a current project that's using novel satellite observations from ICESat-2. This satellite is measuring the freeboard of the sea ice, which is the height of ice above sea level. We now have about five years’ worth of Antarctic sea ice freeboard data, which we’re working on using to figure out how we can constrain sea ice projections, especially in the context of improving climate models with more detailed representations of the ice.
I'm also interested in thinking more about small-scale features in the upper ocean. There are some specific observations from recent Arctic expeditions that I'd love to investigate whether they are similarly seen in the Antarctic. In the Arctic, we’ve observed that these really small-scale upper ocean features change how the melt of the ice evolves. We’re interested in what the implications to coupled systems of the biology and biogeochemistry might be as well. I do hope to get back to do Antarctic field work at some point; I would love to go back down there.
I hope you get to go back soon! Steve also mentioned the connections between sea ice and other fields.
Steve has really forged the way for interdisciplinary collaboration throughout his career. He started the Gordon Research Conference on Polar Marine Science, which has been fundamental to the sea ice community in bringing together people doing physics and more ecology-focused work. He's always been really good about bringing those people together in the field as well, in addition to these workshop and meeting environments.
Speaking of meetings, you attended the 2018 SCAR Open Science Conference in Davos. What was your experience like at that conference and what was your impression of the Antarctic science community?
People really like working together to take advantage of the opportunities globally that are available to do science in this place that's really hard to get to.
That was an awesome meeting, and it was really my first opportunity to join the international Antarctic science community at a meeting. I found it super welcoming and it seems like a pretty tight-knit community on the global scale, which is awesome. People really like working together to take advantage of the opportunities globally that are available to do science in this place that's really hard to get to.
I was also able to attend some side meetings for different projects, learn about data sets, and discover how some of the observations that I made could help support other science that was being done. So, the meeting really did help me build some collaborations.
It’s great that you were able to make new connections! Do you have any advice for early career scientists who want to get involved in Antarctic or polar research?
There are still so many things that we haven't learned from data that we've already collected.
I think that the biggest thing that has helped me in getting my career going is building these connections and getting to know people across the field. Especially in the Antarctic, the opportunities to get there can be limited and it can be quite challenging. Building those connections with established researchers really can help open a lot of doors.
I also think there's a lot of existing and historical data sets that are still really underutilized. Talking to people in the field and learning what data they have that they're really excited about can also open a lot of doors for collaborations. This may be easier to get going than projects that rely on new field data. There are still so many things that we haven't learned from data that we've already collected.
That’s valuable advice, and SCAR provides access to a ton of data and databases! Thank you for sharing, Maddie.