Randy Koster: Modeling the Ways of Water

Randy Koster: Modeling the Ways of Water
by Staff Writers
Greenbelt MD (SPX) May 03, 2023

Randal D. "Randy" Koster, a research scientist at NASA's Goddard Space Flight Center, has been modeling Earth's water and land-surface processes for over three decades. In an interview, Koster shared his passion for understanding how the land interacts with the rest of the climate system, aiming to improve climate predictability.

Koster works in the Global Modeling and Assimilation Office (GMAO), where a team of experts model the Earth's system, including the atmosphere, ocean, land surface, and ice sheets. "As a group, we model the Earth's system: the atmosphere, the ocean, the land surface, the ice sheets, and how they all interact. As a part of that, we ingest observations, including satellite observations, into our modeling systems through a process called data assimilation," he explained. By combining modeled physics with observations, Koster and his team can create the best representation of what is happening in the real world, which can then be used as a starting point for weather forecasts.

Koster's favorite research project throughout his career has been the monthly prediction of hydrology-related variables. "Determining whether or not knowing a hydrological state, say soil moisture, tells you something about what will happen with, say, air temperature, precipitation, or streamflow in the next month or two is very exciting," he said. His work contributes to a better understanding of the interconnectedness of the climate system and potential societal benefits.

Koster is driven by his desire to answer questions about the climate system's predictability. "Just how does the land interact with the rest of the climate system? If the land surface affects the atmosphere, does this change turn around and affect the land surface right back, in some sort of feedback loop? There's still a lot about predictability that we don't know," he elaborated.

His broader goal is to continue contributing to the GMAO by testing ideas through data and model experiments. "It's wonderful to sit at my computer and, pressing a button, see a graph come on the screen that tells whether or not the idea worked out. I want to keep being able to do that - to keep trying out new ideas until I retire," Koster shared.

When asked about his advice for those interested in his area of study, Koster emphasized the importance of setting aside time for the fulfilling aspects of science. "Make sure you set aside some time to do the fun stuff in science, which, for me, is coming up with ideas and finding out whether or not they are supported by the available data."

With a six-word memoir summarizing his career, Koster said, "Make sure your work is fun!" His dedication to research and passion for understanding Earth's complex systems will undoubtedly continue to influence the field of hydrology and climate modeling.