Gwenn E. Flowers

The 2024 Julia and Johannes Weertman Medal is awarded to Gwenn E. Flowers for outstanding research in the field of the theoretical and observational hydrology of glaciers, ice caps and continental ice masses.

Gwenn Flowers is a Professor and Graduate Program Director in the Department of Earth Sciences, Simon Fraser University. For over two decades she has led the theoretical and observational development of the hydrology of glaciers, ice caps and continental ice masses. This effort is vital for understanding the role that ice masses play in the global climate system, through the impact of subglacial drainage on the dynamic response of glaciers.

Flowers’ work facilitates the utilisation of hydrological resources and evaluation of hazard potential ranging from the dynamics of glacier outburst floods to the fast glacier flow called surging. Flowers has advanced the theoretical and numerical treatment of glacial hydrology by developing time-dependent distributed glaciohydraulic models that yield new insights and deeper understanding of glacier behaviour. One offspring of Flowers’ work led to a coupled sheet-conduit model for jökulhlaup propagation, describing the exceptionally fast flowing 1996 jökulhlaup (outburst flood) from the subglacial lake Grímsvötn, Vatnajökull. Standard models could not explain the rapid drainage, but the new model was able to simulate how floodwater initially disperses in a turbulent subglacial sheet which feeds a nascent system of conduits. This work was a breakthrough for understanding the nature of fast-flowing outburst of water from glacier lakes. Her approach and methods have profound implications for the future development of glaciology.

As a scientist, Flowers is disciplined and focused. She has an outstanding understanding of physics and applied mathematics, exceptional analytical capability, and a rare ability to express herself clearly both in writing and orally. Anyone wishing an example of clear writing should read Flowers’ 2018 Nature comment on the hydrology and the future of the Greenland Ice Sheet. This illustrates her ability to articulate complex topics, and emphasizes the relevance of her research on one of the pre-eminent issues of the day. She summarises the history of our thought about the roles of surface hydrology of glaciers and ice sheets in governing the dynamics of the ice, the difficulties of measuring these roles, and the challenges the community faces. It is as good a call to action as I have read. That Flowers was tapped to craft this comment is testimony to her prominence in the field, and to her ability to play the role of spokesperson for it.

Finally, she is a generous scientist. She unselfishly shares her knowledge with colleagues and the public, as advisor and scientific supervisor of graduate students, mentor, and host of several early career and postdoctoral fellows, bringing forth a future generation of glaciologists.

By all standards, Flowers has an outstanding set of scientific contributions that rise to the eminence expected of candidates for the Julia and Johannes Weertman Medal of the EGU. To this must be added her mentoring of students, and her service to the scientific community that itself deserves recognition.