Wen Li

Boston University / UCLA

2017 James B. Macelwane Medal Winner

Robert E. Kopp, Michael P. Lamb, Yan Lavallée, Wen Li, and Tiffany A. Shaw were awarded the 2017 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held on 13 December 2017 in New Orleans, La. The medal is for “significant contributions to the geophysical sciences by an outstanding early career scientist.”


Wen Li has published several outstanding research papers showing how ­wave–​­particle interactions play a key role in controlling the dynamic evolution of the Earth’s Van Allen radiation belts. She has pioneered the use of ­low-​­altitude satellite data as a proxy for the global distribution of plasma waves at much higher altitudes.

Wen Li started her work on the Earth’s radiation belts as a Ph.D. student at the University of California, Los Angeles. One of her greatest achievements is to show that a particular class of plasma waves, known as electromagnetic ion cyclotron waves, can cause rapid loss of relativistic electrons that are otherwise trapped inside the external magnetic field of the Earth, a region known as the Van Allen radiation belts. She showed that most of the losses occur during the main part of a geomagnetic storm and that later on, as conditions recover from the storm, there is another class of plasma waves that can accelerate electrons to relativistic energies. Thus, she was able to show how ­wave–​­particle interactions play a key role in controlling the dynamic variability of the belts.

In order to quantify acceleration and loss on a global scale, one needs to know the global distribution of plasma waves. However, the properties of these waves vary considerably in space and time, making this a challenging problem. Wen Li developed a novel technique of using particle data from satellites in low-Earth orbit to calculate the properties of plasma waves along the geomagnetic field near the equatorial region. Because there are several satellites in low-Earth orbit, Wen was able to develop a global distribution of plasma waves with much higher spatial and temporal resolution than ever before. This technique has been adopted by other research groups and incorporated into global radiation belt models, which have shown a vast improvement. Wen’s work has had a major impact and illustrates her creativity and lateral thinking.

Wen Li has published 120 papers, including 2 in Nature and 1 in Science. This is astonishing for an ­early-​­career scientist with only 7 years since her Ph.D. She is a member of the NASA Time History of Events and Macroscale Interactions during Substorms (­THEMIS), Van Allen Probes, and now Juno mission science teams, and collaborates widely.

Wen Li has recently taken up a new position as assistant professor at Boston University. She is a shining example of excellent research, international collaboration, and leadership for the next generation.

—Richard Horne, British Antarctic Survey, Cambridge, U.K.


I would like to thank Richard Horne for his generous citation and nomination. I am deeply grateful to Vassilis Angelopoulos, Mary Hudson, and Craig Kletzing for their strong support in this nomination process. I also really thank the Macelwane Medal Committee and AGU for this distinct honor.

My career has significantly benefited from support and encouragement from many of my dear colleagues, to whom I can never express my gratitude sufficiently. As a student, I was very fortunate to work under the guidance of professors who are passionate and dedicated to research and teaching: my Ph.D. adviser, Richard Thorne, at the University of California, Los Angeles (UCLA), and my undergraduate adviser, Youqiu Hu, at the University of Science and Technology of China. They taught me how to have fun in the wonderful world of space physics with their keen scientific insight, enthusiasm for science, and great sense of humor in life.

My Ph.D. research at UCLA started when the new NASA ­THEMIS mission led by Vassilis Angelopoulos was launched. The ­THEMIS mission opened the door for me to learn how to find and solve interesting scientific problems from the satellite data. Over this period, I also received generous help from the theoreticians and modelers, particularly Richard Thorne, Richard Horne, Jacob Bornik, and Yuri Shprits. During my postdoctoral research, I was truly fortunate to work on the Van Allen Probes data with many excellent team members, particularly Mary Hudson and Craig Kletzing, who have been warmly supporting my career development. My early career at UCLA greatly benefited from an extremely productive research atmosphere by working with my outstanding colleagues and friends, particularly Jacob Bortnik, Qianli Ma, Lunjin Chen, Zin Tao, and Binbin Ni, as well as many other colleagues with whom I have had a chance to work.

I am also really grateful to my colleagues at Boston University, who are very supportive of my research and teaching in the present early stage of my career as a faculty member by sharing their valuable experience and providing insightful suggestions. It has also been a great pleasure to work with my dear students and postdocs at Boston University, and I believe the best is yet to come.

Finally, I would like to give my special thanks to my family, in particular, my dearest colleague and husband, Toshi Nishimura, who was a recipient of the Macelwane Medal last year, for sharing numerous precious moments with me both academically and personally.

—Wen Li, Boston University, Boston, Mass.