Citation for Jiwen Fan

Jiwen Fan
Jiwen Fan

The Atmosphere Sciences section of the American Geophysical Union (AGU) is pleased to award one of the four 2015 Ascent Awards to Dr. Jiwen Fan of the Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory (PNNL) for “her outstanding contributions in improving understanding of fundamental physical processes in aerosol-cloud interactions.”

Jiwen’s research covers a broad scope ranging from tropospheric chemistry to aerosol-cloud interactions. Among her most impressive contributions is her dedicated effort in providing better understanding of aerosol effects on deep convective clouds. Over the last 10 years, she conducted a series of seminal studies in which she used advanced methodologies and computationally intensive modeling tools to demonstrate how aerosols can impact convection, clouds, weather, and climate through various mechanisms. Of these studies, her findings that vertical wind shear is one of the key environmental factors determining whether aerosols invigorate or suppress convection and that aerosol microphysical invigoration is a dominant mechanism explaining the ubiquitously observed increase of cloud cover and cloud top height by aerosols are widely recognized. Additionally, Jiwen has also been at the forefront of addressing the challenge of improving cloud microphysics parameterizations, particularly on ice nucleation for models.

Her accomplishments and contributions are succinctly summarized in a statement in one of her supporting letters: “I consider that the combination of the breadth, productivity, and impact of her research most uniquely distinguishes her from most of her peers.” Another stated that “she is the most creative, productive, and diligent young scientist I have ever known and worked with.”

We are extremely pleased to present a 2015 Atmospheric Sciences Ascent Award to Dr. Jiwen Fan.

—William K. M. Lau, University of Maryland, College Park


Thank you, Bill, for the generous citation. I am honored to be selected as one of the recipients of the Ascent Award. I am grateful to the AGU Atmospheric Sciences section and the selection committee for this recognition. I humbly accept on behalf of the many people who helped make this possible. Deepest thanks to Zhanqing Li for the nomination and to Daniel Rosenfeld, Bob Houze, and Gerald North, who wrote supporting letters.

I am extremely grateful to my Ph.D. dissertation adviser, Renyi Zhang, for introducing me to the atmospheric field, mentoring me in my efforts to become a scientist, and guiding my career development over the years. I extend many thanks to my postdoc mentors Jennifer Comstock and Mikhail Ovchinnikov for bringing me to PNNL and to the field of atmospheric observation.

I consider myself very fortunate to be able to sustain long-term collaborative relationships with several people through working on challenging problems in the field of aerosol-cloud-climate interactions. I would like to mention especially Zhanqing Li, Danny Rosenfeld, Ruby Leung, Alex Khain, Wei-Kuo Tao, and, more recently, Guang Zhang, Kuan-Man Xu, and Steve Ghan. Whatever success I have had in research is due in large part to them, as well as to my past and current postdocs, visiting scientists, and graduate students. I hope that we are able to keep working together in the future as well.

In my very early career, I learned a lot from colleagues in Renyi’s group, Wei-Kuo Tao’s group, and Zhanqing’s group, and I appreciate their help and collaboration. I wish to thank my PNNL colleagues and managers for their help and support of my professional growth.

I also want to thank Department of Energy program managers Ashley Williamson, Sally McFarlane, Renu Joseph, and Dorothy Koch and PNNL project managers Ruby Leung, Steve Ghan, and Jerome Fast for their funding support of my research.

Finally, I want to thank my family, my parents, sisters, and brother and my husband and our two sons, for their love and support.

—Jiwen Fan, Pacific Northwest National Laboratory, Richland, Wash.

Citation for Andrew Gettelman

Andrew Gettelman
Andrew Gettelman

Andrew is best known for his powerful contributions to the understanding of exchange processes between the stratosphere and troposphere and the representation of clouds in global climate models. His work led to substantially improved understanding of the mechanisms responsible for the dehydration of air entering the tropical stratosphere. His transformative studies on the tropical tropopause layer helped define a new research area. “Andrew’s studies on tropical tropopause layer, cloud microphysics and aerosol-cloud interactions place him at the top of his field,” stated one of the supporting letters. His nominator pointed out that “Andrew’s work is unique in that it links basic processes and observations with global models. Andrew is an exceptional scientist: I know very few atmospheric scientists at his stage of career whose accomplishments have Andrew’s breadth and depth.”

We congratulate Dr. Andrew Gettelman, winner of a 2015 Ascent Award “for outstanding contributions to the understanding of stratosphere-troposphere exchange and modeling and understanding of cloud effects in the climate system.”

—William K. M. Lau, University of Maryland, College Park


It is a great honor to receive this award. I have been fortunate in my career to have had the support and the opportunity to learn from some fantastic mentors. These include some who are no longer with us. I want to recognize the enduring impact of Professor Jim Holton, my adviser, and Dr. Byron Boville, one of my postdoctoral supervisors and mentors as a young scientist. I learned from them explicitly and by example not just how to do research but to conduct science collaboratively. Their examples taught me how to critically work with data and models together and also how to work with a community of researchers.

Science, particularly atmospheric science, does not take place in a vacuum. I have also been privileged to work with expert collaborators over the years as well, from whom I have learned much, including Qiang Fu, Bill Randel, Phil Rasch, Hugh Morrison, and Vincent Larson. I thank many different other mentors at the National Center for Atmospheric Research and beyond for believing in me and supporting my work and providing an exciting and amazing environment in which to conduct research and a platform for collaborating with and communicating that research to others.

I hope I can justify my colleagues’ confidence in me with high-quality and impactful future research and by instilling in the next generation of scientists some of the things that I have learned from the previous generation.

Finally, I wish to thank my family, especially my wife, Francesca, and our kids, Fiona and Natalie, for their support and willingness to explore new opportunities and new places with me as I have collaborated with other researchers around the world.

—Andrew Gettelman, National Center for Atmospheric Research, Boulder, Colo.

Citation for Allen L. Robinson

Allen L. Robinson
Allen L. Robinson

Allen Robinson has transformed our understanding of primary aerosol emissions. Fine particles dominate uncertainties in climate forcing and health effects from pollution. Atmospheric evolution receives substantial focus, but sources are often neglected. This is a pity; without good emissions data model results are guaranteed to be garbage. For whatever reason, particle nucleation is a hot topic generating frequent papers in Science and Nature, but primary emissions are an “engineering” problem. Robinson et al. (Science, 2007, doi:10.1126/science.1133061) is a counterexample. Allen’s paper established that primary organic emissions are substantially semivolatile, with a great deal of evaporation happening while plumes dilute down to ambient conditions, along with simultaneous oxidation chemistry driving recondensation of organic oxidation products as secondary organic aerosol.

Allen and his research group have systematically explored this cycle of emission, evaporation, oxidation, and secondary condensation for major primary organic aerosol sources. Another paper in Science (Jimenez et al., 2009, doi:10.1126/science.1180353) put into context ambient observations using an aerosol mass spectrometer, which almost always reveal that most organic particulate matter is highly oxidized, with only a small fraction consisting of reduced material characteristic of primary emissions. This contradicts predictions by chemical transport models representing the state of the art in the mid-2000s that most organic aerosols were primary. The Robinson cycle was key to resolving this apparent contradiction. The same cycle also explains aerosol observations off of the Deep Water Horizon spill (de Gouw et al., Science, 2011, doi:10.1126/science.1200320).

Allen is a fantastic colleague and collaborator. Collaboration comes so easily that it is hard to write the detailed management plans for proposal calls that presume it is hard; “he sits on the couch in my office and we figure it out” does not always review well. He sees real-world problems with clarity and depth and makes the work easy and fun.

—Neil M. Donahue, Carnegie Mellon University, Pittsburgh, Pa.


I am grateful for and humbled by the acknowledgement of this award. Thank you to my nominators and the AGU Atmospheric Sciences section awards committee for this honor.

I have so much appreciation for all of those who have influenced my path, starting with my mother, my uncle (Nick Latham), and my grandfather (Allen Latham Jr.). They instilled a love for the outdoors and engineering. I was introduced to environmental engineering as student at Stanford and Berkeley. As a postdoctoral fellow at Sandia, I learned about combustion and emissions. I am grateful for sage advice from my mentors (Gil Masters at Stanford, Rich Sextro and Bill Nazaroff at Lawrence Berkeley National Laboratory/University of California, Berkeley, and Larry Baxter at Sandia). My career took a strong turn toward the atmosphere when I joined the faculty at Carnegie Mellon. The Environmental Protection Agency had recently promulgated a new standard for fine particulate matter. I can still remember my lunch with Spyros Pandis that started me down the path of characterizing particle emissions from combustion systems. I cannot thank my colleagues at Carnegie Mellon enough—Spyros Pandis, Cliff Davidson (now at Syracuse), Neil Donahue, and Peter Adams. I attribute much of my success to our vigorous collaboration. I especially want to thank Neil, with whom I have explored problems ranging from organic aerosols to bike wobble. He is an incredible colleague. I also want to thank my many other colleagues at Carnegie Mellon and other institutions with whom I have worked and from whom I have learned over the years. Finally, none of this would have been possible without the many fantastic students and postdocs with whom I have had the honor to work. It really takes a village.

To my amazing and supportive wife, Kathy, and our two sons, Jack and Gus, thank you for being a constant source of joy.

—Allen L. Robinson, Carnegie Mellon University, Pittsburgh, Pa.

Citation for Allison Steiner

Allison Steiner
Allison Steiner

The Atmosphere Sciences section of AGU is pleased to award one of the four 2015 Ascent Awards to Professor Allison Steiner, Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, for “her outstanding contributions to interdisciplinary studies encompassing biosphere-atmosphere interactions, regional climate, air-quality and chemistry-climate connections.”

Dr. Steiner is a world leader in the field of biosphere-atmosphere interactions. She employs a variety of tools and techniques involving both physical and chemical process models, regional chemistry-climate models, and laboratory measurements. With these tools, she has positioned her research group for decades of discovery at the intersection of fields often considered separately, including climate, atmospheric chemistry, air pollution, and land-biosphere-atmosphere exchange. Allison’s scientific leadership, communication skills, and engaging personality make her a highly sought after speaker at major conferences and workshops. As a testimony to her stature in the field, she was invited by the National Science Foundation and the National Research Council to serve on a highly visible National Academies of Sciences, Engineering, and Medicine panel tasked to help chart the future path for the atmospheric chemistry discipline.

In addition to her outstanding research contributions, Allison has also been a pioneer and leader in strengthening the geoscience community. Examples include serving as founder and leader of the Earth Science Women’s Network and as editor for Journal of Geophysical Research: Atmospheres, with special responsibility in biosphere-land-atmosphere areas.

We are extremely pleased to present a 2015 Atmospheric Sciences Ascent Award to Professor Allison Steiner.

—William K. M. Lau, University of Maryland, College Park


Thank you very much for this award, and I am very grateful to my nominators and the Atmospheric Sciences section awards committee for this honor. I pursued a degree in atmospheric sciences as a way of trying to understand the world around me—looking up at the sky, watching the trees, and visualizing the chemistry of these interactions are a constant source of inspiration to me. This award is particularly meaningful to me as I realize that this pursuit is as much about the scientific community as it is about the science, and I would not be at this point without this community support. I would like to thank my dissertation adviser at Georgia Tech, Bill Chameides, for allowing me to find my own scientific path and providing an amazing example of the ingenuity and commitment required for this career. I thank my postdoctoral advisers at the University of California, Berkeley, including Allen Goldstein, Ron Cohen, and Rob Harley, as well as Inez Fung for providing an extremely exciting and rewarding place to be a postdoc. I would also like to thank my colleagues at Michigan and members of my research group over the past 10 years for helping me to grow as a scientist and develop the research that is being honored today. And perhaps just as important as the formal mentors has been my peer network, including the founding members of the Earth Science Women’s Network (ESWN). ESWN grew out of conversations at a 2002 AGU meeting, and these women continue to advise and inspire me throughout my career. Finally, a special thank you to my family and my husband, Deryl Seale, for his constant support and covering childcare to enable me to take “just one more trip.”

—Allison L. Steiner, University of Michigan, Ann Arbor

Citation: AGU (2015), Fan, Gettelman, Robinson, and Steiner receive the 2015 Atmospheric Sciences Ascent Award, Eos, 96, doi:10.1029/2015EO035185. Published on 10 September 2015.

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