University of Colorado Boulder
As a University of South Carolina marine sciences undergraduate, Riley Brady initially expected to research whales, sharks or crabs. Instead, he met with a professor who described simulations of ocean currents and climate. “What? That exists in this field?” Brady remembers thinking. Though he had steered toward biology, he’d always had diverse interests. “I couldn't figure out what I wanted to do. All I knew is that I really loved math. I really liked physics. I really liked science.”
Brady, a Department of Energy Computational Science Graduate Fellowship (DOE CSGF) recipient, was soon immersed in multidisciplinary research, learning to program in the MATLAB framework and to use climate models. He also helped his advisor, new faculty member Ryan Rykaczewski, order and build computers. “We just jumped right in when I was 18 years old, and it was amazing,” Brady says.
Brady studies upwelling within a 30-kilometer-wide band that follows the Pacific coast from the U.S.-Canadian border to Baja California. Within this area, cold waters rise from the depths, ferrying nutrients such as nitrates, phosphates, iron and carbon to the surface. This natural fertilizer supports phytoplankton that fish and other sea creatures eat. This current system and others like it cover just 2 percent of the world’s ocean surface but support 25 percent of commercial fish.
At South Carolina, Brady focused on the physics of the California Current and modeled how climate change would affect it. (He also nearly completed a second major in German and spent six months in southeastern Germany.)
For his Ph.D. with Nicole Lovenduski at the University of Colorado Boulder, Brady examines biogeochemistry, with a focus on how coastal upwelling affects the carbon cycle. The ocean absorbs carbon dioxide from the atmosphere over long periods, dissolving and storing it as bicarbonate and carbonate ions. This makes oceans more acidic, especially in the California Current, where waters have already taken up remineralized carbon from organic matter and decomposed shells in the ocean’s depths. Bathing in corrosive water harms corals and makes it more difficult for snails, oysters and other animals to build new shells. Brady recently applied a forecasting system to predict the water’s acidity in these current systems over a five-year period.
Brady’s research on the California Current has involved primarily regional-scale studies using the decades-old Community Earth System Model. During his 2018 Los Alamos National Laboratory practicum with Mathew Maltrud and Phillip Wolfram, he used a newer model: DOE’s Energy Exascale Earth System Model (E3SM). Brady and his Los Alamos colleagues simulated carbon chemistry in the oceans over 50 years. Besides dividing the ocean into a computational grid, they seeded the globe with virtual electronic floats – the equivalent of adding small, rubber duck-like objects and following how currents moved them. In 2020, Brady will head to Oak Ridge National Laboratory for a second practicum with Forrest Hoffman, where he’ll examine carbon cycling on land, a system whose total mitigating effect on carbon emissions equals that of the ocean.
Working at Los Alamos helped Brady achieve one of his primary Ph.D. goals: running his own climate model. He’s also used data visualization skills he learned on his practicum. “I've made some really cool videos,” shared regularly on Twitter. “They communicate to people on a different level.”
Though Brady initially learned programming on his own, he says the DOE CSGF program of study, practicum and annual reviews helped him set a personal mission statement: “I'm doing computing.” Toward that end, he’s built earth sciences software tools in Python, the high-level programming language. In 2019, he and a German colleague released the first version of climpred, a data analysis toolkit for making climate predictions. The package leverages cutting-edge ways to work with high-dimensional data in Python, he says, letting researchers apply analysis tools from weather and climate forecasting.
Brady plans to graduate by spring 2021 and is aiming for a position at a government research laboratory where he can continue working on computational science and climate. “I’ve found something where I can program all day, but I feel extremely passionate about how I'm applying it.”
Video caption: During his 2018 practicum at Los Alamos National Laboratory, Riley Brady explored the carbon cycle in the Southern Ocean using DOE’s Energy Exascale Earth System Model (E3SM). This video shows currents carrying dissolved organic carbon. Yellows are lower concentrations; purples are higher concentrations. Credit: Riley Brady, Stephanie Zeller & Annie Bares.