A Scientist's Life: Grant Deane

Oceanographer studies how much bubbles can reveal about the state of the oceans

Grant Deane is a research oceanographer at Scripps Institution of Oceanography at UC San Diego. He received his bachelor’s degree in physics from the University of Auckland in New Zealand in 1982 and his DPhil (PhD) from Oxford University in 1989. He joined Scripps in 1990.

explorations now: What do you do for a living?

Grant Deane: I study the role of the ocean in weather and climate. And to do that, I study what happens in storms and how bits of the ocean end up in the atmosphere. I go up to the Arctic and I study what happens when ice falls into the ocean. I also do a fair amount of work on bubbles, interestingly enough – bubbles made by breaking waves, bubbles in glacier ice, and bubbles in the ocean.

It may seem odd that bubbles are a serious scientific area of study, but they are. When the wind blows over the ocean and waves break, whitecaps form, and whitecaps are white because the water right where the wave is breaking is filled with a swarm of tiny bubbles. Those bubbles collect material that's in the water. They rise to the surface and they form foam. And when that foam bursts, it produces a spray of tiny droplets that then go into the atmosphere and they form cloud drops and raindrops and snow. Up in Arctic regions, glacier ice is full of bubbles. Glacial ice is white because it's full of little bubbles that have been pressurized over time because of the weight of the ice above.

When those bubbles finally meet the ocean, they burst out into the water, making a lot of noise, and we're using the sound of those bubbles to figure out how quickly the ice is melting. Colleagues and I are using the splashing sounds of icebergs to figure out how much is falling off the glaciers. Bubbles show up in a surprising variety of ways in the ocean. When an iceberg cracks in water, you're hearing the sound of the ice cracking when glacier ice melts. You're hearing the sound of air exploding out of little bubbles. So it's akin but different. In fact, in the 1970s, you could buy a product that contained glacier ice to have with your evening drink. People would put it into their glass and enjoy the sounds of the air bursting out of the ice. Now we're using those sounds to figure out how quickly the glaciers are melting.

en: What are some of the main questions in your field?

GD: Something that we've learned over the last decade is how complicated boundaries are, which are where the ocean meets the atmosphere, where the ice meets the water. And these boundaries involve chemistry, biology, and physics, all of it. One of the goals is to understand the complexity of these boundaries and the role that these boundaries play in weather and climate through truly interdisciplinary studies. You need oceanographers, but you also need atmospheric chemists and you need marine biologists. We're trying to understand the organic chemistry, how the compounds made by marine life end up in the clouds because they alter the properties of the clouds. And we are learning about the transfer process, how the organic compounds get out of the ocean and into the atmosphere, what chemistry is involved, and how that alters the formation of the clouds. These processes are very important and will profoundly impact our future in ways that we don't fully understand yet.

en:  What are some of the tools of your trade?

GD: I like to do experiments. So I have a laboratory where I do experiments. I also like to go out into the field. So I mount expeditions and we go out to sea or we go up to the Arctic and we measure what's going on there. I also like theoretical work. We use mathematics to build theoretical models of what we're looking at to explain nature. We also build new instruments to take with us, new sensors to measure new things as we go out in these field expeditions or with laboratory experiments. We use acoustics extensively, but we also use a wide variety of other sensors. We use cameras. We use devices that measure the properties of the biology in the water. We look at ocean color and how much light propagates through the ocean at different wavelengths, to figure out some of the chemistry in the ocean. We measure the ocean salinity and the ocean temperature.

We're building a new facility at Scripps called the Scripps Ocean-Atmosphere Research Simulator. We call it SOARS. This instrument will replicate the ocean boundary. It's a hundred feet long and eight feet by eight feet square. It will blow winds up to gale force conditions, 19-meter-per-second winds. That's about 40 knots. We can get the water temperature down to freezing and all the way up to tropical conditions and we can make the air freezing so that we can make sea ice in the simulator.

And it's all built from non-toxic construction materials so that we can grow marine organisms. It has bright lights over the top for growing photosynthetic organisms. We can reproduce the chemistry, the biology and the oceanography of the boundary. We're very excited about this new capability. It's a bridge between laboratory-scale experiments and full-scale ocean deployments. 

A colleague, Scripps oceanographer Dale Stokes, and I are building an autonomous glider to go out to sea and photograph the bubbles in the ocean so that we can understand the impact of breaking waves on the exchange of gas. Roughly 30 percent of the carbon dioxide that human activities release into the atmosphere ends up in the ocean and bubbles help transport it. That's a good thing and a bad thing. It's good that it's out of the atmosphere, but it increases the acidity of the ocean. It's important to understand how much of that gas gets transported. During storms, that transport is increased because of the effect of the bubbles in the waves.

en: What made you want to come to Scripps?

GD: When I was younger, I always wanted to be a marine biologist. Although I made it as a physical oceanographer, my passion for marine biology always stayed with me. When I went to school and then graduate school I studied math and physics, but I didn't lose my love of the ocean. When an opportunity came up to take a career position at Scripps Oceanography, I jumped at the chance. I moved here in 1990 and I've been very happy over the last 30 years. I'm really passionate about finding answers to the questions that drive our future. What is sea-level rise going to be 50 years from now, a hundred years from now? What's the average global temperature going to be 50 years from now, a hundred years from now?

What kind of weather are we going to be experiencing? What is the ocean going to look like? What are the polar regions going to look like? And I would really like to work hard to be part of the mission to figure these things out. I'm very excited about the tools that we can build at Scripps Oceanography. SOARS is a great example. I'm excited to get out into the field and I'm most excited about working with younger people, the next generation of scientists who are going to get out there and study these problems and find answers to these pressing and critical questions. So I love working with young people. They're passionate, they're enlivened, and they care about the planet and our future. It's wonderful to work with them. 

 

About Scripps Oceanography

Scripps Institution of Oceanography at the University of California San Diego is one of the world’s most important centers for global earth science research and education. In its second century of discovery, Scripps scientists work to understand and protect the planet, and investigate our oceans, Earth, and atmosphere to find solutions to our greatest environmental challenges. Scripps offers unparalleled education and training for the next generation of scientific and environmental leaders through its undergraduate, master’s and doctoral programs. The institution also operates a fleet of four oceanographic research vessels, and is home to Birch Aquarium at Scripps, the public exploration center that welcomes 500,000 visitors each year.

About UC San Diego

At the University of California San Diego, we embrace a culture of exploration and experimentation. Established in 1960, UC San Diego has been shaped by exceptional scholars who aren’t afraid to look deeper, challenge expectations and redefine conventional wisdom. As one of the top 15 research universities in the world, we are driving innovation and change to advance society, propel economic growth and make our world a better place. Learn more at www.ucsd.edu.

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