It is my great pleasure to introduce Prof. Seulgi Moon as the recipient of the 2022 Luna B. Leopold Early Career Award. In her short career, Prof. Moon has already made several seminal contributions to the current understanding of landscape evolution and surface processes on Earth and other solar system bodies. These contributions reflect her innovative integration of fundamental physics and chemistry, numerical modeling, and state-of-the-art laboratory techniques. First, she has elucidated local, regional, and global budgets of silica weathering. Second, she assessed the interactive and coupled effects of tectonics, climate, topography, and lithology on fluvial and glacial erosion and transport in active orogenic systems. Third, she quantified the impact of topography-induced stresses on physical weathering processes. The latter research subject is specifically relevant regarding current efforts to determine the nature and evolution of the critical zone that supports surface and near-surface biological activity on our planet. In addition to her work on the Earth, Prof. Moon has also made significant contributions to planetary studies including the formation of cold traps on (her namesake body) the Moon and fluvial fans on the Saturnian icy-satellite Titan. Her research also provides, for the first time, a quantitative linkage between engineering-based site parameters and attributes of morphological features. Finally, Prof. Moon and her colleagues developed a new Quaternary dating method using optically stimulated luminescence (OSL) methods. Her exceptional mentoring record and her contribution to broadening the participation of students from underrepresented social groups illustrate her full dimension as a leader in the Earth and planetary science community. It is with all of the above achievements that I present to you this year’s recipient of the AGU Luna B. Leopold Early Career Award. —An Yin, Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles

I am deeply honored to receive the Luna B. Leopold Early Career Award. This award will be a constant reminder for me to be like Luna B. Leopold, who was a quantitative, creative, and inspiring geomorphologist. As a young girl who grew up on a small farm in South Korea, I was fascinated by natural environments. I dreamed about becoming a scientist but never imagined I would receive this prestigious award. I would like to thank An Yin for the generous citation and Taylor Perron, Efi Foufoula-Georgiou, Kelin Whipple, and Bill Dietrich for supporting the nomination. Like Luna, I enjoyed collaborations with scientists from the diverse research fields of geomorphology, geochemistry, geophysics, hydrology, rock mechanics, and critical zone sciences. These collaborations allowed me to appreciate the beauty of interdisciplinary studies on Earth’s surface, seek a comprehensive understanding of surface and subsurface processes, and investigate measurable interactions and consequences of those processes in various landscapes. I share this award with my mentors, colleagues, and collaborators who contributed to my scientific growth. I would like to especially thank my graduate adviser, George Hilley, at Stanford University and postdoc adviser, Taylor Perron, at Massachusetts Institute of Technology, who have significantly affected my career. George guided me through multiple research projects on weathering and erosion processes. He generously and patiently taught me how to develop testable scientific hypotheses, connect field observations to numerical models, and perform rigorous quantitative analysis. Taylor provided me with guidance, support, and inspiration to explore the connections among surface topography, subsurface stress, and bedrock fracturing. I am also grateful for my graduate advisers, YoungSook Huh at Seoul National University and Page Chamberlain at Stanford, who guided my research on chemical weathering in rivers during my early years. My mentors and colleagues helped broaden my research horizons. I would also like to thank Steve Holbrook and Cliff Riebe for guiding me through integrating geophysical and geomorphic techniques; Steve Martel for discussing rock mechanics; the critical zone community including Suzanne Anderson, Sue Brantley, Bill Dietrich, and Team Bedrock for field measurements and comprehensive analysis; and Brad Goodfellow, Diego Mas Ivars, Gen Li, Nathan Brown, and Eitan Shelef for insightful discussions. In the past years, my colleagues, postdocs, and students at the University of California, Los Angeles have provided me an intellectually vibrant environment. I would like to give thanks to An Yin, Kenzie Day, David Paige, Jonathan Mitchell, and others who introduced me to planetary surface studies. Last, I thank my friends and family for their continuing support. —Seulgi Moon, Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles