“Spotlight Series” is a group of posts designed to introduce you to the other members of the science team on the research expedition. Each scientist and his/her research will be featured – I provided the prompts and the scientists added their own information (my comments will be in brackets: [ ]). Feel free to ask questions about what they are studying and how they became interested in science!
Dr. Sarah Fawcett
Dr. Fawcett, born and raised in South Africa, is currently completing her post-doctoral research at Princeton University.
What is your field of study? I consider myself a marine biogeochemist. Interested in using various chemical tracer to understand biological processes – basically, how are the microscopic plants (phytoplankton) that live in the global surface ocean affected by ocean chemistry, and how do they in turn change ocean chemistry. I work on the nitrogen cycle because nitrogen is essential for life and also determines how much photosynthesis happens in the ocean (plants need N to grow). Photosynthesis is what takes CO2 out of the atmosphere and puts it into the ocean, which ties nitrogen directly to carbon and climate. This is true of all climate – the past, present, and future. We can use the nitrogen tracer to tell us about climate throughout history.
What information do you hope to find on the expedition? I’m collecting phytoplankton by filtering huge volumes of seawater and concentrating the phytoplankton that live in it onto a filter .
Back in the lab, I measure the Nitrogen isotope ratio (i.e. N-15:N-14) of different phytoplankton groups, which tells me about the form of nitrogen (nitrate or ammonium) that they have been consuming. If they rely mainly on nitrate, which is mixed up into sunlit surface waters from the deep ocean, they act as a net remover of atmospheric carbon dioxide, and are therefore important for the C-cycle and climate. Ammonium, on the other hand, is recycled over and over in surface waters so that its consumption by phytoplankton has no net effect on carbon dioxide.
[go back and look at the picture of Dr. Fawcett – next to her you can see the setup of her lab. The large jugs of water on the left are the samples collected from the ocean. Each jug is connected to a clear, round yo-yo looking device . These contain the filters that collect the phytoplankton. Once all the water is filtered through, she removes and freezes the filters so she can study them further]
How did you become interested in science? I have always been interested in marine science because it was such a big part of my life growing up. South Africa is a beautiful country geologically and I’ve always been interested in how things work. I do what I do because I’m really interested in feedback cycles and the balance the Earth has – there’s no better way to think about the world than to think about the biogeochemistry. It’s truly fascinating.
Educational background: I received my undergraduate degree in Earth and Planetary Science from Harvard and my PhD from Princeton in geosciences. I’m currently a post-doctoral research associate.
Plans for the future: I would like to be a professor in Cape Town, South Africa because I’d have access to the South Atlantic, Indian, and Southern Ocean (the ocean around Antarctica). There are so many intriguing questions directly related to how our planet works and why it’s habitable that have to do directly with these oceans (particularly the Southern Ocean, which is the largest). We have no idea how to answer some of these questions, and I think that’s really exciting. We can also learn a lot about past climate: by drilling into the ocean floor and measuring the chemical composition of the shells of microfossils that died and sank to the bottom of the ocean thousands of years ago, we can actually reconstruct what climate was like in the past, and begin to understand, for example, why the Earth has ice ages.
Back to Ms. B:
Dr. Fawcett’s research is truly fascinating and will be hugely beneficial to our understanding of the Earth. I hope she has inspired some ideas of your own!
I will be featuring the other scientists as the voyage continues so you’ll be exposed to lots of different research ideas.
Don’t forget to comment on the posts! You can always use Edmodo to ask a question/comment if you prefer.
Until next time,