Grad Student

Shaina Rogstad, Climate Modeler

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My PhD work focuses on climate modeling, oceanography, and climate change. However, I have many scientific interests and in the past my research has been in astrophysics, physics, and applied mathematics researching a wide variety of topics including galactic evolution, quantum mechanics, and gravitational waves.

Shaina (fourth from right) after she defended her master’s thesis. Here, she is pictured with her research group as part of the Applied Math program at UMass Amherst. The research she presented was on modeling Solitons and Vorticies in Bose Einstein Condensates (or negative mass).

I use computer simulations to look at ways the global climate might change as Antarctica melts. As the ice sheet melts, water runs off and chunks of ice calve off from the sheet and float out into the ocean. The world’s oceans are all connected and water moves around allowing it to distribute heat, salt, and nutrients around the planet.  All of the water and ice running off changes how salty the water is and that in turn impacts that movement altering aspects of the climate such as global temperatures and precipitation patterns. Every part of the climate system is connected in these really complex but deeply beautiful ways. I study those connections to learn what might happen to the climate in the future.

Currently I am using data from Rob DeConto and Dave Pollard’s (2016) regional ice sheet simulations that they developed to model the Antarctic ice sheets. This data are really cool because their modeling techniques are state of the art. When their results were published in 2016 it made a big splash both in the scientific community and in the media. Now I am using their data, which was modeled just for Antarctica, along with the Intergovernmental Panel on Climate Change’s Representative Concentration Pathways data, which describes how greenhouse gas concentrations in the atmosphere could evolve, and putting it into a global model that ties together land, atmosphere, oceans, and ice to take the research one step forward and see what their predictions for Antarctica might mean for the climate system as a whole.

A model image from Shaina’s current PhD work. On the left is the amount of runoff (melted ice that is flowing into the ocean) around Antarctica in year 2017. On the right is the modeled amount of runoff around Antarctica under increased CO2 scenarios in the year 2117. Runoff is measured in sverdrups (SV), which is a unit of volume transport. 1 SV is equal to 264,000,000 US gallons per second!

Most people are aware that the polar ice caps are melting as the planet heats up from all of our greenhouse gas emissions. This melting has significant impacts for how climate will change. There are a lot of feedbacks in the climate system and so there are these interactions where climate change causes the ice caps to melt and the melting of the ice caps then causes the climate to change in other ways such as altering ocean circulation. My research specifically looks at how the melting of the Antarctic ice sheet might change the climate, with a focus on changes in ocean circulation. Ocean circulation has a large influence on the planet with ramifications for global temperatures, sea ice distributions, and wind patterns. There is a subtle interplay between all of these things and I will be trying to determine what might happen based on what the computer simulations predict. The goal is to shed light on what may happen to our climate as the melting occurs in hopes of furthering our knowledge and spurring action to mitigate the severity of climate change.

One of my favorite parts of being a scientist is learning how our universe works. I used to be an astronomer and studied stars and galaxies, then I worked on gravitational waves and quantum mechanics, and now I study the earth and the oceans. I love learning all I can about how natural systems work because they have a fascinating logic to them all centering on physics and mathematics and it is very beautiful to me.

My advice to young scientists is to find a support group who will encourage you to grow and explore. Being a scientist can be difficult and occasionally a bit lonely. Most of what kept me going throughout undergrad and my masters work were my fellow students in the programs and clubs I was involved in, and my mom who is always a great cheerleader for me. There will be a lot of times along the way that it will be discouraging, especially if you are a member of a group traditionally underrepresented in the sciences. It is really helpful to have people to work with, study with, and talk to through the tough times. In addition to giving you the support to continue with your work you will also gain friends and collaborators that you will have going forward in your career and in your life.

To learn more about Shaina and the research she does, follow her on Twitter here!

Helen Habicht, Molecular Paleoclimatologist

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I am a molecular paleoclimatologist, meaning I examine organic molecules (biomarkers) preserved in the geologic record to study past climate and environmental change. Biomarkers are compounds which can be traced to a single organism, class of organisms, or environmental process. They are useful tools for reconstructing climate, environment, and ecosystem changes because they record conditions at the time of their deposition, and can be preserved in sediments for millions of years.

My research is focused on discovering how the climate and environment in the Arctic has changed in the past. Due to anthropogenic (human-induced) climate change, the Arctic is currently undergoing rapid and unprecedented change. Paleoclimate records help us understand the natural variability of the climate system. They provide perspective on the extent and rapidity of current change, and can help predict how climate may change in the future.

A ‘Tree of Life’ illustrating the three domains of life and some biomarkers characteristic of the major groups of organisms. Many of these compounds can be preserved in sediments and rocks. Molecular paleoclimatologists study how the presence, absence, or variations in chemistry of these compounds relates to environmental controls such as temperature or primary productivity. Figure adapted from Briggs and Summons (2014).
Lake sediments contain organic compounds from terrestrial  (land) and aquatic sources such as higher land plants, microbes living in surrounding soils or the lake sediments themselves, and various kinds of algae and microorganisms that live in the water column. Using biomarkers, it is possible to examine contributions to sedimentary organic matter from the three domains of life, bacteria, archaea and eukarya as in the figure on the right, thus providing accurate paleoenvironmental information. As lake sediments accumulate, the oldest material will be at the bottom and the youngest material at the top. By analyzing samples from a sediment core, we observe how climate and environment at the lake change through time. Figure adapted from Castañeda and Schouten (2011).

My study site is Lake El’gygytgyn (Lake E), a meteorite impact crater formed 3.6 million years ago, located in northeast Russia ~100 km north of the Arctic Circle. I generate my data by extracting the organic material from samples from a sediment core from the bottom of the lake. I measure abundances and distributions of the biomarkers preserved in the sediments to reconstruct climatic and ecosystem changes over the last one million years. This period of Earth’s history is part of the Pleistocene, an epoch dominated by strong alternations between cold glacial periods and warm interglacial periods (see the ‘CO2: Past, Present, Future‘ page for a discussion on glacial and interglacial periods). By examining the biomarkers at Lake E, I can determine changes in variables such as temperature and precipitation associated with these climatic cycles. I can also use the biomarkers to identify what plants lived around the lake, and what sorts of primary producers (algae) were present in the lake. This information on past environmental variability is valuable as the climate continues to change rapidly.

I love being a scientist because I get to learn something new every day! There are always new questions to be asked and answers to be found either in my own research or the scientific literature. I enjoy working with colleagues and students to generate datasets that provide new insight about Earth’s climate. I also love that my job provides me with many opportunities to travel and meet new people!

For anyone who wants to be a scientists, know that being a graduate student is often incredibly challenging. There is so much to learn, so much research to be done, and numerous demands on your time. I think it is essential to develop a strong support network. This can include family, friends, your cohort, colleagues, and mentors. These people will help encourage and inspire you if you get discouraged or distressed by the trials of scientific research. They will remind you why you began a career in science in the first place—your love of learning!

Follow Helen on her personal Twitter here and/or on the UMass Biogeochemistry Twitter here to learn more about her research!

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