Feature Stories 2024: From apprentice to expert: A UMass Dartmouth mentorship story

PhD student Agata Piffer Braga and Professor Dan MacDonald at SMAST looking at the autonomous underwater vehicle T-REMUS
Feature Stories 2024: From apprentice to expert: A UMass Dartmouth mentorship story
From apprentice to expert: A UMass Dartmouth mentorship story

Engineering/SMAST professor Daniel MacDonald and PhD student Agata Piffer Braga share their research and their perspectives from both sides of mentorship

At UMass Dartmouth, doctoral students become full-fledged researchers through the guidance of a faculty mentor. Professors and students work together on exciting and innovative research projects that have local and global implications. But beyond the research itself, the mentor-mentee relationship helps new scientists gain the confidence and experience they need to be successful in their fields.

Agata Piffer Braga PhD '24 came to UMass Dartmouth from Sao Paulo, Brazil to work with Professor Daniel MacDonald in the Engineering and Applied Science: Computational Science and Engineering program.  Using first-of-its-kind autonomous underwater vehicle technology at UMassD's School for Marine Science and Technology (SMAST), Piffer Braga and MacDonald study the dynamics of river plumes that form where rivers meet the ocean. 

Here, they give us a behind-the-scenes look at their research and the transformation that takes place as PhD students go from apprentice to expert.  

An aerial view of a boat on the Merrimack River

The research: Where rivers meet the ocean 

Funded by the National Science Foundation and in collaboration with the University of Maine and the University of Connecticut, MacDonald and Piffer Braga's research project focuses on what happens when fresh water from rivers meets the ocean. This project is focused specifically on the frontal zone of the plume and the mixing that occurs there.  

Why does this research matter? 

"In March 2011, an accident at a New Hampshire sewage treatment center sent millions of plastic discs floating down the Merrimack River and out to sea, eventually washing up on the shores of Europe," MacDonald explained. "That's just one example that illustrates how what's in our rivers gets into our oceans, carrying nutrients, pollutants, sediments, and more. This work also has potential implications for climate change models. As glaciers melt, they release tons of freshwater into the sea, with some of the same dynamics we're observing in the river plumes. This project can improve our understanding of what happens when freshwater goes into saltwater, and what we learn here can be applied to other areas." 

Piffer Braga added, "Understanding the fate of the plume will affect coastal management, water quality around the river mouth, and the people that live nearby in these coastal communities.  I like that my work is connected to the surrounding coastal communities. It brings oceanography closer to real life."   

Agata Piffer Braga catches a drone in midair
Piffer Braga catches a drone in midair

At work on the water 

The research begins with getting out in the field to collect data. For oceanographers, that means taking to the water. Piffer Braga and MacDonald boarded a boat on the Merrimack River near Newburyport to collect measurements and observations. They employed a unique, first-of-its-kind sampling system using an autonomous underwater vehicle (AUV) equipped with turbulence sensors, a drone to capture aerial images, and water samples taken from the boat.  

New methods of discovery 

"Our AUV is called the T-REMUS, or turbulence microsensor-equipped remote environmental monitoring units. Ours is the first REMUS AUV equipped with these kinds of turbulence sensors. It was acquired by SMAST in 2004, and I inherited it from a mentor of mine, Louis Goodman, when he retired from UMass Dartmouth." 

The T-REMUS is programmed to travel around a buoy stationed in the front of the river plume, all while the drone is capturing images overhead. This combination of multiple data sources produces a fuller picture than scientists have previously had. 

"No one has data like this," MacDonald said. "I'm excited for Agata to get to do this for her thesis." 

"This new sampling method is challenging because it gives us so much data to work with, but we're able to get much higher-resolution measurements," Piffer Braga added.  

Merrimack River plume where freshwater meets the ocean
Merrimack River plume where the river meets the ocean, observable by the difference in color between fresh and salt water

The transformative power of mentorship

From the mentor's perspective: 

"I see it as a partnership with the student," MacDonald says of his role as a mentor. "It's like an apprenticeship; PhD students learn the craft of conducting research, asking the right questions, and telling a story with science. That's something I got from my own PhD advisor; it's not just about data, it's also about telling a story. We want to be able to communicate about our work with both the public and the scientific community. 

"When a PhD student comes in, they may have some research experience, but they're not a full-fledged research scientist yet. Agata came to UMassD with phenomenal computational and coding skills. What we do at the PhD level is harness those skills and strengths and build upon them."  

MacDonald describes the transformation he has witnessed after working with Piffer Braga since 2019: "Over the years I can see her thought process evolving. As we progress, she starts to take charge and I become more of a sounding board than an instructor. That's a sign of personal growth as she becomes more confident, more independent, and more an expert on this project than I am. 

"Apart from this one project, I encourage Agata to take advantage of other opportunities that come her way. She's had the opportunity to travel abroad, to teach, and to collaborate with other researchers. I think it's important for her to have these experiences and get a broader view of science."  

From the mentee's perspective: 

"Working with Dr. MacDonald has been fantastic. He is very patient and understanding when I'm struggling, but he also gives me autonomy and independence to analyze the data on my own and then we discuss it together. It's fun to sit down at our weekly research meetings and ask questions and explore different ideas.  

"I've grown so much throughout this process. When I started, I didn't know anything about river plumes; it was all very new to me. I see things more clearly and I can see the bigger picture now. I've learned how to search for answers; if I don’t know something, I know how to find out." 

Dr. Dan MacDonald and Agata Piffer Braga in the lab
MacDonald and Piffer Braga in the lab

Q&A with Agata Piffer Braga PhD '24

Why did you choose to come to UMass Dartmouth for your PhD? 

"My advisor at the University of Sao Paulo Ilson Silveira has a longstanding relationship with UMass Dartmouth. I came to visit SMAST when I was an undergraduate student, and always wanted to come here for my PhD. I knew if I came here, I would have a great advisor and get to work on interesting projects." 

What do you like most about UMass Dartmouth and SMAST? 

"This school is in a great location; we're right on the water, and I love seeing the seasons change. The classes are great. I spend most of my time at SMAST, but I also enjoy going to the library on the main campus to work.  The staff here – like Andre Schmidt and Arlene Wilkinson – have been so helpful to me and have made me feel at home away from home. Even given the challenges of adjusting to a new place and a new language, I would do it all again." 

What are your plans for the future? 

"I hope to obtain a post-doctoral position and continue research in physical oceanography. I hope to work with Dr. MacDonald and the people I've met here at SMAST throughout the rest of my career."