Arlene Fiore got interested in air pollution first as a kid in the Boston suburbs, partly because she suffered from bad asthma, and that taught her that the air can be harmful. Even though her interest in the Earth’s atmosphere was there from an early age on, the path that led her to her current position as a professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences was, in her own words, a circuitous one, partly because of life's inherent unpredictability and coincidences, but also because of Arlene's wide array of interests. When it came to thinking about what to do in college, she struggled to make a decision: "And then when I was thinking about college I really didn't know what I wanted to do. I mean, I really had broad interests—I liked history, I liked math and science, I liked English. […] The things that I started thinking about though were really probably more geared towards engineering, and that was because my dad was an engineer. I was [also] pretty serious about track and cross country running, [and so] I was trying to find places where I could run and do all these things. In the end I applied to a bunch of places, and my mom had really wanted to see if I could get into Harvard, and so I applied there and I vividly remember telling her she was wasting her $50 application fee because there was no way." Those $50, as history would have it, became a pivotal investment in Arlene's life—she got into Harvard, where it was eventually the earth and planetary science courses that captivated her, and where she soon started to do research in atmospheric chemistry in Daniel Jacob’s group. She ended up staying at Harvard for a PhD, a decision that had taken some nudging by those around her, who saw Arlene’s potential more clearly than she saw it herself. Arlene has become an expert in atmospheric chemistry, air pollution, atmospheric transport, and climate. She uses numerical models to understand all the different factors that influence the concentration of constituents that affect human health, especially ozone. Her early work was about defining the “background” ozone that sets the floor for air quality regulations, and especially understanding the role of long-range transport of ozone itself as well as its precursors. Her work has uncovered linkages between air quality and climate change, for example by highlighting the role of methane, a greenhouse gas, in regulating ground level ozone. And she’s made important contributions on a range of other topics, including not just chemistry but, more lately, physical climate, including extreme events. From the beginning Arlene’s research has had direct implications for policy. Translating between the abstract world of atmospheric chemistry and the concrete realities of policy and regulation, Arlene has been working with a range of stakeholders to influence regulation and practice at the federal, state and local levels. Yet she does this stakeholder-engaged policy work while remaining a highly productive basic researcher whose work contributes to fundamental understanding. Listening to Arlene, you’ll notice that she has a rare combination of personal talent and a profound commitment to collective scientific progress, and an ability to shine while ensuring others do too. The interview with Arlene Fiore was recorded in September 2023. Image credit: Steph Stevens website of Arlene's group at MIT