Investigating how ice melting and mixing affects the ocean deepens our understanding of the scale of the climate crisis.
When we think of oceanography, we often think of beautiful, dramatic landscapes and adventures on the high seas, but the reality is colder, wetter and involves a lot of troubleshooting, says Kevin McGraw, a PhD researcher at the University of Galway.
McGraw’s research uses a robotic instrument called the Air-Sea Interaction Profiler (ASIP) to investigate fine-scale turbulence in the upper ocean.
“Oceanography can feel abstract, especially when it involves turbulence or remote regions, so I try to show what it looks like behind the scenes,” he says.
“Whether that’s a robotic profiler being deployed in icy water or a map showing where we’ve been, I think visuals make the science more tangible.”
Since starting in 2022, McGraw has taken part in several oceanographic campaigns aboard the RV Celtic Explorer, focusing on the waters around Greenland and the subpolar North Atlantic.
“These expeditions have allowed me to collect in situ observations of dynamic and understudied regions where physical processes like mixing and stratification strongly influence climate-relevant phenomena.”
Tell us about your current research.
One of the main phenomena I’m studying is called cabbeling, a process that occurs when two water masses with the same density but different temperature and salinity mix, resulting in a denser mixture that sinks. This sets off turbulence and vertical mixing, which plays a role in how heat and freshwater are distributed in the ocean, especially in the Arctic.
During a 2022 expedition to the Greenland Sea, we used ASIP to capture one of the first fine-scale observations of this process in the wild.
Because cabbeling is short-lived and hard to detect using conventional tools, we were only able to observe it thanks to the high temporal resolution and autonomous operation of ASIP.
In your opinion, why is your research important?
Processes such as ice melt and warming seas are rapidly altering the structure of the upper ocean, especially at high latitudes. These changes affect everything from the vertical movement of heat and nutrients to the seasonal cycling of carbon.
A related area of interest for me is how physics influences the biological carbon pump, which helps regulate atmospheric carbon dioxide through the seasonal growth and sinking of phytoplankton.
During our 2023 campaign in the Labrador Sea, we observed clear links between physical conditions like stratification and biological indicators such as chlorophyll and oxygen.
By improving our understanding of small-scale turbulence and mixing, this research helps refine the larger picture of ocean-climate interactions.
What inspired you to become a researcher?
Before starting my PhD, I spent several years working in field-based technical roles that gave me a front-row seat to oceanographic data collection in action.
As an airborne system operator, I found myself flying low over the ocean in small airplanes using high-resolution digital imaging systems to survey the distribution and abundance of marine wildlife in support of offshore wind environmental assessments.
Later I was employed at sea supporting autonomous underwater vehicle operations for deep-sea mapping, marine exploration and shipwreck discovery. We operated around the clock in challenging conditions launching and recovering vehicles, troubleshooting systems and monitoring survey data in real time. That work gave me an appreciation for the scale and complexity of ocean operations.
That dual exposure to shipboard and aerial perspectives gradually pulled me towards research. I realised I wanted to go beyond just collecting data and start asking questions about the processes shaping what we were seeing.
The ocean’s surface, once just a backdrop to the work, became the focus of my curiosity. That interest eventually brought me to the University of Galway, where I now study small-scale physical processes in the upper ocean using robotic profilers, returning to the sea now as part of the scientific team.
What are some of the biggest challenges or misconceptions you face as a researcher in your field?
One of the biggest challenges is the fieldwork itself. Being at sea for weeks at a time means working long shifts, in close quarters, and in unpredictable conditions. It’s physically demanding and mentally tiring but it’s also where the most valuable data is collected.
There’s often a romantic idea of oceanography involving dramatic landscapes and clear skies, but the reality is usually cold, wet and full of troubleshooting. Still, the sense of purpose and collaboration that comes from working with a dedicated team at sea makes it incredibly rewarding.
Do you think public engagement with science and data has changed in recent years?
Absolutely it has, in both positive and complicated ways. The Covid-19 pandemic brought science and data into people’s daily lives in an unprecedented way. Terms such as ‘modelling’, ‘uncertainty’, and ‘transmission rate’ became part of everyday conversation. That exposure helped more people understand that science is a process, not a fixed set of facts, and that evidence evolves over time. It also highlighted the importance of clear, transparent communication.
At the same time, it sparked wider discussions about trust both in science itself and in how it’s used by governments or institutions. In some cases, public engagement with science became polarised, with people treating scientific findings as something to support or challenge based on personal or political views. That’s a challenge we still face.
In ocean science, I’ve seen a stronger emphasis on open data, real-time observations, and visual storytelling ways of helping people connect with the natural world and understand how changes in the ocean affect their lives.
There’s a growing sense that scientists need to meet the public where they are, not assume understanding or trust by default. That shift has made science communication more intentional and, I think, more effective.
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