Aiken Fellowship report – Tim Higgins
The George R. Aiken Graduate Fellowship supports CU «Ƶ graduate students conducting water-related research. Tim Higgins, a PhD candidate in the department of Atmospheric and Oceanic Sciences, is investigating the impacts of climate change on atmospheric rivers and extreme precipitation events that affect the western United States. With his fellowship funds, Higgins traveled to the World Climate Research Program (WCRP) Open Science Conference in Kigali, Rwanda to present his research.
In October 2023, I used my fellowship funds to attend the second ever . This conference takes place once every ten years and brought together climate scientists from around the world to discuss recent findings in climate research and solutions towards a more sustainable and resilient future. The conference ended with the “Kigali Declaration”: a statement signed by many of the conference participants that was subsequently submitted to the 28th Conference of Parties (COP28).
At the conference, I presented some of my recent work on changes to atmospheric rivers resulting from climate change and discussed it with other scientists who had a wide variety of different backgrounds and perspectives. Atmospheric rivers are elongated structures of water vapor in the lower atmosphere that can stretch for several thousand kilometers over the ocean. When they collide with elevated terrain on the coastline, they can be destructive and cause flooding. Atmospheric rivers are expected to strengthen in the future because the amount of water that air can hold increases as temperatures increase. My study focuses on understanding changes to rare extreme atmospheric river events impacting the U.S. West Coast.
To understand changes to rare extreme events, a large amount of data from climate model runs is required, which can be computationally expensive. I was able to extract data from a project that addressed this issue by using computing power from many volunteers’ computers. The abundance of model data created another challenge, which was finding a way to efficiently and accurately track the events. I was able to circumvent this by using a machine learning algorithm trained on human expert hand labels and validating it against other common tracking methods in a previous study (Higgins et al. 2023). I generated statistics that quantified changes to the strength of extreme events, seasonal changes to extreme events, and changes to frequencies of extreme events under varying “weather regimes,” which are persistent patterns of atmospheric flow that can last for over a week. The results indicate that unprecedented events are highly likely going to occur in even the mildest warming scenarios. Ultimately, my work is contributing towards solving the puzzle of how we can expect our climate system to change in the future.
Reference: Higgins, T. B., Subramanian, A. C., Graubner, A., Kapp‐Schwoerer, L., Watson, P. A. G., Sparrow, S., et al. (2023). . Journal of Advances in Modeling Earth Systems, 15(4): e2022MS003495. doi 10.1029/2022MS003495
See also
Tim Higgins hikes across a rope bridge in the rainforest in Nyungwe National Park after the conclusion of the conference.
The Kigali Convention Centre, which hosted the 2023 WCRP Open Science Conference.