Madden-Julian Oscillation and Atmospheric Rivers: S2S Forecast of High-Impact Weather Extremes

Abstract
Part 1: Atmospheric rivers transport vast quantities of water vapor globally, some of which translates into tremendous rainfall and potential flooding. For atmospheric rivers that make landfall on the West Coast of the U.S., much of that water vapor is sourced from tropical reservoirs in the Pacific Ocean like the Intertropical Convergence Zone. One such source, the Madden Julian Oscillation, has been studied in connection with atmospheric rivers either statistically (its presence increasing the likelihood of intense rainfall) or through its modulation of jet streams in Pacific Basin altering atmospheric rivers’ trajectories. The Madden Julian Oscillation’s impact as a direct water vapor source on atmospheric river intensity and potential rainfall has been relatively unexplored, however. This portion of the talk will present research findings showing that atmospheric rivers with the Madden Julian Oscillation as a direct water vapor source are characteristically different, and notably more intense than atmospheric rivers not using the Madden Julian Oscillation as a direct water vapor reservoir. In particular, these atmospheric rivers are larger, carry more water, and move that water vapor more intensely. These results highlight the Madden Julian Oscillation’s importance in atmospheric river intensification, and as an essential part of our seasonal-to-subseasonal forecasting repertoire.

Part 2: The Madden Julian Oscillation is the largest source of interannual variability in the tropics. This massive system can affect everything from atmospheric rivers to wildfires in the U.S., and abroad. Despite these well-studied impacts, mention of the Madden Julian Oscillation is noticeably absent from news coverage on weather extremes. This portion of the talk will demonstrate how scientists can communicate their research in a way that is salient, digestible, and more likely to be picked up by popular media. In particular, a popular science article on the Madden Julian Oscillation will be used as a case study for how a publicly niche, yet academically well-discussed, topic can be transformed into a reader-friendly format.

Bio: Chad Small is a second year PhD student in Atmospheric Sciences at the University of Washington. Chad’s current research investigates how multiscale phenomena can interact to intensify rainfall, and consequently, potential flooding. He is a recipient of the National Defense Science and Engineering Graduate (NDSEG) Fellowship. Outside of science, Chad has spent the last five years writing as environmental justice reporter and science writer in both freelance and full-time capacities. He is currently the Climate Fellow at the Bulletin of the Atomic Scientists, and his other work has been featured in Grist, Next City, and Gothamist. He holds a BS in Environmental Engineering from Yale University and a MS in Earth and Atmospheric Science from the City College of New York.