Armin Sorooshian has made extraordinary contributions to the cross-disciplinary fields of atmospheric chemistry and environmental engineering, in particular with regard to air pollution and aerosol-cloud interactions, combining both development of innovative measurement technologies with understanding of physical and chemical processes. His contributions to instrument development have advanced measurement capabilities for aerosol particles and clouds on airborne platforms, with data collected crossing a handful of disciplinary boundaries in terms of impact and implications. He characterized the first particle-into-liquid sampler for offline measurement of water-soluble aerosol composition, and now a growing number of groups internationally use this design for aerosol characterization studies. He introduced the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe, which has been used in a number of recent field projects. These studies led to impactful findings, such as how particles can collapse and shrink upon humidification, which impacts remote sensing retrievals and treatment of aerosol-water interactions in models. He has led numerous airborne field campaigns with the above instruments and others that have advanced knowledge of how clouds both redistribute particles spatially and modify aerosol composition. In particular, he is leading a $30 million 6-year (2019-2024) NASA Earth Venture Suborbital mission (ACTIVATE) focused on aerosol-cloud-meteorology interactions over the northwest Atlantic Ocean. Using in-cloud measurements for the first time, his group showed that trace metals in cloud drops can destroy organic species in the aqueous phase. His seminal work on the precipitation susceptibility of clouds to aerosol perturbations discovered that clouds within a finite range of liquid water are most vulnerable to aerosol pollution in terms of precipitation suppression. He also helped unravel processes related to how aqueous-phase drop chemistry produces secondary organic aerosols.

Besides atmospheric sciences, his group’s work has contributed to the multidisciplinary areas of natural hazards, global environmental change, biogeosciences, hydrology and public health. His team’s measurements near mine tailing sites in Arizona have raised public awareness about metal(loid) contamination in local aerosol particles. His multidisciplinary contributions have been recognized by the AGU Atmospheric Sciences Ascent Award and the Office of Naval Research Young Investigator Award. Aside from leading major field missions, Armin has trained a new group of upcoming researchers. He has supervised 19 Ph.D. dissertations and is currently advising 12 Ph.D. students; his graduate and undergraduate students have been included in 111 papers. He has also mentored students from Philippine high schools, the Manila Observatory and other schools such as in Bermuda as part of NASA field missions.

— Xubin Zeng
University of Arizona
Tucson, Arizona

— Antonio J. Busalacchi
University Corporation for Atmospheric Research
Boulder, Colorado

Researching aerosol particles and clouds not only is challenging but has provided me with one of the best career tracks I could have ever imagined over the last 20 years. I am greatly humbled to receive a recognition bearing Joanne Simpson’s name; I am inspired by how she broke barriers with field campaigns, and that motivates me to give the next generation of students unique chances to get involved with field work. I thank AGU and my nominators, led by Xubin Zeng and Antonio Busalacchi. I owe deep credit to my parents, Shirin and Soroosh, and my brother, Jamshid; they have supported me through all my peaks and valleys. My father has served as a role model for many in the AGU community, and I am lucky to have been one of those beneficiaries. I’ve been blessed with remarkable mentors, including my Ph.D. advisers, John Seinfeld and Rick Flagan, at the California Institute of Technology (Caltech). They trusted me in a number of ways, such as with using new custom-made instruments and giving me the amazing experience of doing airborne field work and encouraging me to serve as a flight scientist. My best research training experiences occurred with the Navy Twin Otter and the special group at the Center for Interdisciplinary Remotely Piloted Aircraft Studies, including especially Haf Jonsson, who has had an immeasurable impact on me. The education I got with flying on the Twin Otter was invaluable in helping me reach the point to lead missions with the support of Ron Ferek (Office of Naval Research) and also Hal Maring and Barry Lefer (NASA). I was also lucky to work under the mentorship of Graham Feingold as a postdoc. He has been a constant source of inspiration for me in research. I am thankful as well to Graeme Stephens and also a large contingent from NASA Langley Research Center who worked with me recently in the ACTIVATE field campaign to conduct almost 180 flights during a pandemic, which was one of the hardest yet rewarding parts of my research career. I close by thanking my former and current students at the University of Arizona, with whom I share this recognition; each student has been an important shining light on my path, and I learn each day from them. Last but not least, I thank my wife, Atria, and children, Parsa and Liana, for being a constant source of happiness each day.— Armin Sorooshian, University of Arizona, Tucson, Arizona

Francina Dominguez, Jennifer Murphy, David Noone, Armin Sorooshian, and Rainer M. Volkamer received the 2019 Atmospheric Sciences Ascent Award at AGU’s Fall Meeting 2019, held 9–13 December in San Francisco, Calif. The award recognizes “research contributions by exceptional mid-career scientists in the fields of atmospheric and climate sciences.”  

Armin Sorooshian is uniformly cited as one of the most important scholars worldwide in the field of aerosol–water relationships. He is the author of 123 peer-reviewed journal publications (including 41 papers in AGU journals). Early in his career, he was instrumental in bringing the Particle-into-Liquid Sampler (PILS) into the sphere of aircraft studies. He developed the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe (DASH-SP), the first instrument capable of measuring size-resolved aerosol hygroscopicity with fast time resolution. He also developed a novel Counterflow Virtual Impactor (CVI) inlet for airborne platforms to preferentially sample and evaporate cloud droplets to yield residual particles. Armin’s airborne measurements with the PILS and CVI instruments advanced knowledge of how clouds redistribute particles and modify aerosol composition. He was instrumental in unraveling the processes involved in the production of secondary organic aerosol by aqueous droplet chemistry. His work with the DASH-SP was important in several Navy and NASA airborne missions to advance understanding of aerosol hygroscopic properties. As a postdoctoral fellow with Graham Feingold, Armin used a combination of models, satellite data, and in situ observations to study the precipitation susceptibility of clouds to aerosol perturbations. He has been a leader in airborne fieldwork, as demonstrated by his being a principal investigator with the Navy Twin Otter aircraft in 15 airborne field projects. Armin’s impact in coming years will continue to grow, as evidenced by his having been selected recently as the principal investigator of the Aerosol Cloud Meteorology Interactions over the Western Atlantic Experiment (ACTIVATE), a $30-million NASA Earth Venture Class suborbital mission directed toward understanding aerosol–cloud–meteorology interactions over the western North Atlantic Ocean that will be carried out off the U.S. East Coast during 2019–2023. Furthermore, Armin has trained an impressive group of upcoming researchers in chemical engineering, atmospheric sciences, and public health.

—John H. Seinfeld, California Institute of Technology, Pasadena

I am deeply honored to receive the Ascent Award and am in debt to everyone who has had an impact on my career, including remarkable advisors, a wonderful group of graduate students, and my family. I extend appreciation to my nominators and the selection committee. It is with sadness that the atmospheric sciences community felt a great loss as Fuqing Zhang, my principal nominator, passed away recently. The impact felt by his students and the scientific community from his career’s efforts will continue to be strong. My first role model in academia was my father, who is the reason I chose this profession and from whom I still learn by observation. My Ph.D. advisors, John H. Seinfeld and Richard C. Flagan, gave me remarkable opportunities and taught me by example how to be a mentor. Their trust in me during airborne field projects was significant, as I had the inspiring experience of being a flight scientist during Navy Twin Otter missions. My luck with excellent mentors continued with my postdoctoral advisor, Graham Feingold, who inspired me with his creativity, passion for clouds, and genuine desire to support junior scientists. Other significant mentors throughout my career that I thank include Haflidi Jonsson, Graeme Stephens, Eric Betterton, and Xubin Zeng. I want to acknowledge the Office of Naval Research and NASA, who have supported the majority of my research. A very special group of people I share this award with and for whom I am very thankful are my former and current graduate students from the University of Arizona, each of whom I am proud and lucky to have been able to advise. Last, I thank those who have been the constants throughout my career: my parents, Soroosh and Shirin; my brother, Jamshid; my wife, Atria; and our son, Parsa. —Armin Sorooshian, University of Arizona, Tucson